11bc38b8fSAlexei Starovoitov // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) 28a138aedSMartin KaFai Lau /* Copyright (c) 2018 Facebook */ 38a138aedSMartin KaFai Lau 43289959bSAndrii Nakryiko #include <byteswap.h> 5cdb2f920SArnaldo Carvalho de Melo #include <endian.h> 696408c43SYonghong Song #include <stdio.h> 78a138aedSMartin KaFai Lau #include <stdlib.h> 88a138aedSMartin KaFai Lau #include <string.h> 9e6c64855SAndrii Nakryiko #include <fcntl.h> 108a138aedSMartin KaFai Lau #include <unistd.h> 118a138aedSMartin KaFai Lau #include <errno.h> 12fb2426adSMartin KaFai Lau #include <sys/utsname.h> 13fb2426adSMartin KaFai Lau #include <sys/param.h> 14fb2426adSMartin KaFai Lau #include <sys/stat.h> 15fb2426adSMartin KaFai Lau #include <linux/kernel.h> 168a138aedSMartin KaFai Lau #include <linux/err.h> 178a138aedSMartin KaFai Lau #include <linux/btf.h> 18e6c64855SAndrii Nakryiko #include <gelf.h> 198a138aedSMartin KaFai Lau #include "btf.h" 208a138aedSMartin KaFai Lau #include "bpf.h" 218461ef8bSYonghong Song #include "libbpf.h" 22d72386feSAndrii Nakryiko #include "libbpf_internal.h" 232fc3fc0bSAndrii Nakryiko #include "hashmap.h" 2490d76d3eSAndrii Nakryiko #include "strset.h" 258a138aedSMartin KaFai Lau 26fb2426adSMartin KaFai Lau #define BTF_MAX_NR_TYPES 0x7fffffffU 27fb2426adSMartin KaFai Lau #define BTF_MAX_STR_OFFSET 0x7fffffffU 288a138aedSMartin KaFai Lau 298a138aedSMartin KaFai Lau static struct btf_type btf_void; 308a138aedSMartin KaFai Lau 318a138aedSMartin KaFai Lau struct btf { 323289959bSAndrii Nakryiko /* raw BTF data in native endianness */ 33b8604247SAndrii Nakryiko void *raw_data; 343289959bSAndrii Nakryiko /* raw BTF data in non-native endianness */ 353289959bSAndrii Nakryiko void *raw_data_swapped; 36b8604247SAndrii Nakryiko __u32 raw_size; 373289959bSAndrii Nakryiko /* whether target endianness differs from the native one */ 383289959bSAndrii Nakryiko bool swapped_endian; 39b8604247SAndrii Nakryiko 40b8604247SAndrii Nakryiko /* 419141f75aSAndrii Nakryiko * When BTF is loaded from an ELF or raw memory it is stored 429141f75aSAndrii Nakryiko * in a contiguous memory block. The hdr, type_data, and, strs_data 439141f75aSAndrii Nakryiko * point inside that memory region to their respective parts of BTF 449141f75aSAndrii Nakryiko * representation: 45b8604247SAndrii Nakryiko * 46b8604247SAndrii Nakryiko * +--------------------------------+ 47b8604247SAndrii Nakryiko * | Header | Types | Strings | 48b8604247SAndrii Nakryiko * +--------------------------------+ 49b8604247SAndrii Nakryiko * ^ ^ ^ 50b8604247SAndrii Nakryiko * | | | 51b8604247SAndrii Nakryiko * hdr | | 52b8604247SAndrii Nakryiko * types_data-+ | 53b8604247SAndrii Nakryiko * strs_data------------+ 54919d2b1dSAndrii Nakryiko * 55919d2b1dSAndrii Nakryiko * If BTF data is later modified, e.g., due to types added or 56919d2b1dSAndrii Nakryiko * removed, BTF deduplication performed, etc, this contiguous 57919d2b1dSAndrii Nakryiko * representation is broken up into three independently allocated 58919d2b1dSAndrii Nakryiko * memory regions to be able to modify them independently. 59919d2b1dSAndrii Nakryiko * raw_data is nulled out at that point, but can be later allocated 60919d2b1dSAndrii Nakryiko * and cached again if user calls btf__get_raw_data(), at which point 61919d2b1dSAndrii Nakryiko * raw_data will contain a contiguous copy of header, types, and 62919d2b1dSAndrii Nakryiko * strings: 63919d2b1dSAndrii Nakryiko * 64919d2b1dSAndrii Nakryiko * +----------+ +---------+ +-----------+ 65919d2b1dSAndrii Nakryiko * | Header | | Types | | Strings | 66919d2b1dSAndrii Nakryiko * +----------+ +---------+ +-----------+ 67919d2b1dSAndrii Nakryiko * ^ ^ ^ 68919d2b1dSAndrii Nakryiko * | | | 69919d2b1dSAndrii Nakryiko * hdr | | 70919d2b1dSAndrii Nakryiko * types_data----+ | 7190d76d3eSAndrii Nakryiko * strset__data(strs_set)-----+ 72919d2b1dSAndrii Nakryiko * 73919d2b1dSAndrii Nakryiko * +----------+---------+-----------+ 74919d2b1dSAndrii Nakryiko * | Header | Types | Strings | 75919d2b1dSAndrii Nakryiko * raw_data----->+----------+---------+-----------+ 76b8604247SAndrii Nakryiko */ 778a138aedSMartin KaFai Lau struct btf_header *hdr; 78919d2b1dSAndrii Nakryiko 79b8604247SAndrii Nakryiko void *types_data; 80919d2b1dSAndrii Nakryiko size_t types_data_cap; /* used size stored in hdr->type_len */ 81b8604247SAndrii Nakryiko 82ba451366SAndrii Nakryiko /* type ID to `struct btf_type *` lookup index 83ba451366SAndrii Nakryiko * type_offs[0] corresponds to the first non-VOID type: 84ba451366SAndrii Nakryiko * - for base BTF it's type [1]; 85ba451366SAndrii Nakryiko * - for split BTF it's the first non-base BTF type. 86ba451366SAndrii Nakryiko */ 87740e69c3SAndrii Nakryiko __u32 *type_offs; 88192f5a1fSAndrii Nakryiko size_t type_offs_cap; 89ba451366SAndrii Nakryiko /* number of types in this BTF instance: 90ba451366SAndrii Nakryiko * - doesn't include special [0] void type; 91ba451366SAndrii Nakryiko * - for split BTF counts number of types added on top of base BTF. 92ba451366SAndrii Nakryiko */ 935b891af7SMartin KaFai Lau __u32 nr_types; 94ba451366SAndrii Nakryiko /* if not NULL, points to the base BTF on top of which the current 95ba451366SAndrii Nakryiko * split BTF is based 96ba451366SAndrii Nakryiko */ 97ba451366SAndrii Nakryiko struct btf *base_btf; 98ba451366SAndrii Nakryiko /* BTF type ID of the first type in this BTF instance: 99ba451366SAndrii Nakryiko * - for base BTF it's equal to 1; 100ba451366SAndrii Nakryiko * - for split BTF it's equal to biggest type ID of base BTF plus 1. 101ba451366SAndrii Nakryiko */ 102ba451366SAndrii Nakryiko int start_id; 103ba451366SAndrii Nakryiko /* logical string offset of this BTF instance: 104ba451366SAndrii Nakryiko * - for base BTF it's equal to 0; 105ba451366SAndrii Nakryiko * - for split BTF it's equal to total size of base BTF's string section size. 106ba451366SAndrii Nakryiko */ 107ba451366SAndrii Nakryiko int start_str_off; 108b8604247SAndrii Nakryiko 10990d76d3eSAndrii Nakryiko /* only one of strs_data or strs_set can be non-NULL, depending on 11090d76d3eSAndrii Nakryiko * whether BTF is in a modifiable state (strs_set is used) or not 11190d76d3eSAndrii Nakryiko * (strs_data points inside raw_data) 11290d76d3eSAndrii Nakryiko */ 113919d2b1dSAndrii Nakryiko void *strs_data; 11490d76d3eSAndrii Nakryiko /* a set of unique strings */ 11590d76d3eSAndrii Nakryiko struct strset *strs_set; 116919d2b1dSAndrii Nakryiko /* whether strings are already deduplicated */ 117919d2b1dSAndrii Nakryiko bool strs_deduped; 11888a82c2aSAndrii Nakryiko 119b8604247SAndrii Nakryiko /* BTF object FD, if loaded into kernel */ 1208a138aedSMartin KaFai Lau int fd; 121b8604247SAndrii Nakryiko 122b8604247SAndrii Nakryiko /* Pointer size (in bytes) for a target architecture of this BTF */ 12344ad23dfSAndrii Nakryiko int ptr_sz; 1248a138aedSMartin KaFai Lau }; 1258a138aedSMartin KaFai Lau 126d7f5b5e0SYonghong Song static inline __u64 ptr_to_u64(const void *ptr) 127d7f5b5e0SYonghong Song { 128d7f5b5e0SYonghong Song return (__u64) (unsigned long) ptr; 129d7f5b5e0SYonghong Song } 130d7f5b5e0SYonghong Song 131192f5a1fSAndrii Nakryiko /* Ensure given dynamically allocated memory region pointed to by *data* with 132192f5a1fSAndrii Nakryiko * capacity of *cap_cnt* elements each taking *elem_sz* bytes has enough 133192f5a1fSAndrii Nakryiko * memory to accomodate *add_cnt* new elements, assuming *cur_cnt* elements 134192f5a1fSAndrii Nakryiko * are already used. At most *max_cnt* elements can be ever allocated. 135192f5a1fSAndrii Nakryiko * If necessary, memory is reallocated and all existing data is copied over, 136192f5a1fSAndrii Nakryiko * new pointer to the memory region is stored at *data, new memory region 137192f5a1fSAndrii Nakryiko * capacity (in number of elements) is stored in *cap. 138192f5a1fSAndrii Nakryiko * On success, memory pointer to the beginning of unused memory is returned. 139192f5a1fSAndrii Nakryiko * On error, NULL is returned. 140192f5a1fSAndrii Nakryiko */ 1413b029e06SAndrii Nakryiko void *libbpf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz, 142192f5a1fSAndrii Nakryiko size_t cur_cnt, size_t max_cnt, size_t add_cnt) 1438a138aedSMartin KaFai Lau { 144192f5a1fSAndrii Nakryiko size_t new_cnt; 145192f5a1fSAndrii Nakryiko void *new_data; 1468a138aedSMartin KaFai Lau 147192f5a1fSAndrii Nakryiko if (cur_cnt + add_cnt <= *cap_cnt) 148192f5a1fSAndrii Nakryiko return *data + cur_cnt * elem_sz; 1498a138aedSMartin KaFai Lau 150192f5a1fSAndrii Nakryiko /* requested more than the set limit */ 151192f5a1fSAndrii Nakryiko if (cur_cnt + add_cnt > max_cnt) 152192f5a1fSAndrii Nakryiko return NULL; 1538a138aedSMartin KaFai Lau 154192f5a1fSAndrii Nakryiko new_cnt = *cap_cnt; 155192f5a1fSAndrii Nakryiko new_cnt += new_cnt / 4; /* expand by 25% */ 156192f5a1fSAndrii Nakryiko if (new_cnt < 16) /* but at least 16 elements */ 157192f5a1fSAndrii Nakryiko new_cnt = 16; 158192f5a1fSAndrii Nakryiko if (new_cnt > max_cnt) /* but not exceeding a set limit */ 159192f5a1fSAndrii Nakryiko new_cnt = max_cnt; 160192f5a1fSAndrii Nakryiko if (new_cnt < cur_cnt + add_cnt) /* also ensure we have enough memory */ 161192f5a1fSAndrii Nakryiko new_cnt = cur_cnt + add_cnt; 1628a138aedSMartin KaFai Lau 163192f5a1fSAndrii Nakryiko new_data = libbpf_reallocarray(*data, new_cnt, elem_sz); 164192f5a1fSAndrii Nakryiko if (!new_data) 165192f5a1fSAndrii Nakryiko return NULL; 1668a138aedSMartin KaFai Lau 167192f5a1fSAndrii Nakryiko /* zero out newly allocated portion of memory */ 168192f5a1fSAndrii Nakryiko memset(new_data + (*cap_cnt) * elem_sz, 0, (new_cnt - *cap_cnt) * elem_sz); 169192f5a1fSAndrii Nakryiko 170192f5a1fSAndrii Nakryiko *data = new_data; 171192f5a1fSAndrii Nakryiko *cap_cnt = new_cnt; 172192f5a1fSAndrii Nakryiko return new_data + cur_cnt * elem_sz; 1738a138aedSMartin KaFai Lau } 1748a138aedSMartin KaFai Lau 1759c6c5c48SAndrii Nakryiko /* Ensure given dynamically allocated memory region has enough allocated space 1769c6c5c48SAndrii Nakryiko * to accommodate *need_cnt* elements of size *elem_sz* bytes each 1779c6c5c48SAndrii Nakryiko */ 1783b029e06SAndrii Nakryiko int libbpf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_cnt) 1799c6c5c48SAndrii Nakryiko { 1809c6c5c48SAndrii Nakryiko void *p; 1819c6c5c48SAndrii Nakryiko 1829c6c5c48SAndrii Nakryiko if (need_cnt <= *cap_cnt) 1839c6c5c48SAndrii Nakryiko return 0; 1849c6c5c48SAndrii Nakryiko 1853b029e06SAndrii Nakryiko p = libbpf_add_mem(data, cap_cnt, elem_sz, *cap_cnt, SIZE_MAX, need_cnt - *cap_cnt); 1869c6c5c48SAndrii Nakryiko if (!p) 1879c6c5c48SAndrii Nakryiko return -ENOMEM; 1889c6c5c48SAndrii Nakryiko 1899c6c5c48SAndrii Nakryiko return 0; 1909c6c5c48SAndrii Nakryiko } 1919c6c5c48SAndrii Nakryiko 192192f5a1fSAndrii Nakryiko static int btf_add_type_idx_entry(struct btf *btf, __u32 type_off) 193192f5a1fSAndrii Nakryiko { 194192f5a1fSAndrii Nakryiko __u32 *p; 1958a138aedSMartin KaFai Lau 1963b029e06SAndrii Nakryiko p = libbpf_add_mem((void **)&btf->type_offs, &btf->type_offs_cap, sizeof(__u32), 197ba451366SAndrii Nakryiko btf->nr_types, BTF_MAX_NR_TYPES, 1); 198192f5a1fSAndrii Nakryiko if (!p) 199192f5a1fSAndrii Nakryiko return -ENOMEM; 200192f5a1fSAndrii Nakryiko 201192f5a1fSAndrii Nakryiko *p = type_off; 2028a138aedSMartin KaFai Lau return 0; 2038a138aedSMartin KaFai Lau } 2048a138aedSMartin KaFai Lau 2053289959bSAndrii Nakryiko static void btf_bswap_hdr(struct btf_header *h) 2063289959bSAndrii Nakryiko { 2073289959bSAndrii Nakryiko h->magic = bswap_16(h->magic); 2083289959bSAndrii Nakryiko h->hdr_len = bswap_32(h->hdr_len); 2093289959bSAndrii Nakryiko h->type_off = bswap_32(h->type_off); 2103289959bSAndrii Nakryiko h->type_len = bswap_32(h->type_len); 2113289959bSAndrii Nakryiko h->str_off = bswap_32(h->str_off); 2123289959bSAndrii Nakryiko h->str_len = bswap_32(h->str_len); 2133289959bSAndrii Nakryiko } 2143289959bSAndrii Nakryiko 2158461ef8bSYonghong Song static int btf_parse_hdr(struct btf *btf) 2168a138aedSMartin KaFai Lau { 2173289959bSAndrii Nakryiko struct btf_header *hdr = btf->hdr; 2185b891af7SMartin KaFai Lau __u32 meta_left; 2198a138aedSMartin KaFai Lau 220b8604247SAndrii Nakryiko if (btf->raw_size < sizeof(struct btf_header)) { 2218461ef8bSYonghong Song pr_debug("BTF header not found\n"); 2228a138aedSMartin KaFai Lau return -EINVAL; 2238a138aedSMartin KaFai Lau } 2248a138aedSMartin KaFai Lau 2253289959bSAndrii Nakryiko if (hdr->magic == bswap_16(BTF_MAGIC)) { 2263289959bSAndrii Nakryiko btf->swapped_endian = true; 2273289959bSAndrii Nakryiko if (bswap_32(hdr->hdr_len) != sizeof(struct btf_header)) { 2283289959bSAndrii Nakryiko pr_warn("Can't load BTF with non-native endianness due to unsupported header length %u\n", 2293289959bSAndrii Nakryiko bswap_32(hdr->hdr_len)); 2303289959bSAndrii Nakryiko return -ENOTSUP; 2313289959bSAndrii Nakryiko } 2323289959bSAndrii Nakryiko btf_bswap_hdr(hdr); 2333289959bSAndrii Nakryiko } else if (hdr->magic != BTF_MAGIC) { 2348461ef8bSYonghong Song pr_debug("Invalid BTF magic:%x\n", hdr->magic); 2358a138aedSMartin KaFai Lau return -EINVAL; 2368a138aedSMartin KaFai Lau } 2378a138aedSMartin KaFai Lau 238b8604247SAndrii Nakryiko meta_left = btf->raw_size - sizeof(*hdr); 239d8123624SAndrii Nakryiko if (meta_left < hdr->str_off + hdr->str_len) { 240d8123624SAndrii Nakryiko pr_debug("Invalid BTF total size:%u\n", btf->raw_size); 2418a138aedSMartin KaFai Lau return -EINVAL; 2428a138aedSMartin KaFai Lau } 2438a138aedSMartin KaFai Lau 244d8123624SAndrii Nakryiko if (hdr->type_off + hdr->type_len > hdr->str_off) { 245d8123624SAndrii Nakryiko pr_debug("Invalid BTF data sections layout: type data at %u + %u, strings data at %u + %u\n", 246d8123624SAndrii Nakryiko hdr->type_off, hdr->type_len, hdr->str_off, hdr->str_len); 2478a138aedSMartin KaFai Lau return -EINVAL; 2488a138aedSMartin KaFai Lau } 2498a138aedSMartin KaFai Lau 250d8123624SAndrii Nakryiko if (hdr->type_off % 4) { 2518461ef8bSYonghong Song pr_debug("BTF type section is not aligned to 4 bytes\n"); 2528a138aedSMartin KaFai Lau return -EINVAL; 2538a138aedSMartin KaFai Lau } 2548a138aedSMartin KaFai Lau 2558a138aedSMartin KaFai Lau return 0; 2568a138aedSMartin KaFai Lau } 2578a138aedSMartin KaFai Lau 2588461ef8bSYonghong Song static int btf_parse_str_sec(struct btf *btf) 2598a138aedSMartin KaFai Lau { 2608a138aedSMartin KaFai Lau const struct btf_header *hdr = btf->hdr; 261b8604247SAndrii Nakryiko const char *start = btf->strs_data; 2628a138aedSMartin KaFai Lau const char *end = start + btf->hdr->str_len; 2638a138aedSMartin KaFai Lau 264ba451366SAndrii Nakryiko if (btf->base_btf && hdr->str_len == 0) 265ba451366SAndrii Nakryiko return 0; 266ba451366SAndrii Nakryiko if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_STR_OFFSET || end[-1]) { 2678461ef8bSYonghong Song pr_debug("Invalid BTF string section\n"); 2688a138aedSMartin KaFai Lau return -EINVAL; 2698a138aedSMartin KaFai Lau } 270ba451366SAndrii Nakryiko if (!btf->base_btf && start[0]) { 271ba451366SAndrii Nakryiko pr_debug("Invalid BTF string section\n"); 272ba451366SAndrii Nakryiko return -EINVAL; 273ba451366SAndrii Nakryiko } 2748a138aedSMartin KaFai Lau return 0; 2758a138aedSMartin KaFai Lau } 2768a138aedSMartin KaFai Lau 277740e69c3SAndrii Nakryiko static int btf_type_size(const struct btf_type *t) 27869eaab04SAndrii Nakryiko { 2793289959bSAndrii Nakryiko const int base_size = sizeof(struct btf_type); 280b03bc685SAndrii Nakryiko __u16 vlen = btf_vlen(t); 28169eaab04SAndrii Nakryiko 282b03bc685SAndrii Nakryiko switch (btf_kind(t)) { 28369eaab04SAndrii Nakryiko case BTF_KIND_FWD: 28469eaab04SAndrii Nakryiko case BTF_KIND_CONST: 28569eaab04SAndrii Nakryiko case BTF_KIND_VOLATILE: 28669eaab04SAndrii Nakryiko case BTF_KIND_RESTRICT: 28769eaab04SAndrii Nakryiko case BTF_KIND_PTR: 28869eaab04SAndrii Nakryiko case BTF_KIND_TYPEDEF: 28969eaab04SAndrii Nakryiko case BTF_KIND_FUNC: 29022541a9eSIlya Leoshkevich case BTF_KIND_FLOAT: 29169eaab04SAndrii Nakryiko return base_size; 29269eaab04SAndrii Nakryiko case BTF_KIND_INT: 29369eaab04SAndrii Nakryiko return base_size + sizeof(__u32); 29469eaab04SAndrii Nakryiko case BTF_KIND_ENUM: 29569eaab04SAndrii Nakryiko return base_size + vlen * sizeof(struct btf_enum); 29669eaab04SAndrii Nakryiko case BTF_KIND_ARRAY: 29769eaab04SAndrii Nakryiko return base_size + sizeof(struct btf_array); 29869eaab04SAndrii Nakryiko case BTF_KIND_STRUCT: 29969eaab04SAndrii Nakryiko case BTF_KIND_UNION: 30069eaab04SAndrii Nakryiko return base_size + vlen * sizeof(struct btf_member); 30169eaab04SAndrii Nakryiko case BTF_KIND_FUNC_PROTO: 30269eaab04SAndrii Nakryiko return base_size + vlen * sizeof(struct btf_param); 3031713d68bSDaniel Borkmann case BTF_KIND_VAR: 3041713d68bSDaniel Borkmann return base_size + sizeof(struct btf_var); 3051713d68bSDaniel Borkmann case BTF_KIND_DATASEC: 3061713d68bSDaniel Borkmann return base_size + vlen * sizeof(struct btf_var_secinfo); 30769eaab04SAndrii Nakryiko default: 308b03bc685SAndrii Nakryiko pr_debug("Unsupported BTF_KIND:%u\n", btf_kind(t)); 30969eaab04SAndrii Nakryiko return -EINVAL; 31069eaab04SAndrii Nakryiko } 31169eaab04SAndrii Nakryiko } 31269eaab04SAndrii Nakryiko 3133289959bSAndrii Nakryiko static void btf_bswap_type_base(struct btf_type *t) 3143289959bSAndrii Nakryiko { 3153289959bSAndrii Nakryiko t->name_off = bswap_32(t->name_off); 3163289959bSAndrii Nakryiko t->info = bswap_32(t->info); 3173289959bSAndrii Nakryiko t->type = bswap_32(t->type); 3183289959bSAndrii Nakryiko } 3193289959bSAndrii Nakryiko 3203289959bSAndrii Nakryiko static int btf_bswap_type_rest(struct btf_type *t) 3213289959bSAndrii Nakryiko { 3223289959bSAndrii Nakryiko struct btf_var_secinfo *v; 3233289959bSAndrii Nakryiko struct btf_member *m; 3243289959bSAndrii Nakryiko struct btf_array *a; 3253289959bSAndrii Nakryiko struct btf_param *p; 3263289959bSAndrii Nakryiko struct btf_enum *e; 3273289959bSAndrii Nakryiko __u16 vlen = btf_vlen(t); 3283289959bSAndrii Nakryiko int i; 3293289959bSAndrii Nakryiko 3303289959bSAndrii Nakryiko switch (btf_kind(t)) { 3313289959bSAndrii Nakryiko case BTF_KIND_FWD: 3323289959bSAndrii Nakryiko case BTF_KIND_CONST: 3333289959bSAndrii Nakryiko case BTF_KIND_VOLATILE: 3343289959bSAndrii Nakryiko case BTF_KIND_RESTRICT: 3353289959bSAndrii Nakryiko case BTF_KIND_PTR: 3363289959bSAndrii Nakryiko case BTF_KIND_TYPEDEF: 3373289959bSAndrii Nakryiko case BTF_KIND_FUNC: 33822541a9eSIlya Leoshkevich case BTF_KIND_FLOAT: 3393289959bSAndrii Nakryiko return 0; 3403289959bSAndrii Nakryiko case BTF_KIND_INT: 3413289959bSAndrii Nakryiko *(__u32 *)(t + 1) = bswap_32(*(__u32 *)(t + 1)); 3423289959bSAndrii Nakryiko return 0; 3433289959bSAndrii Nakryiko case BTF_KIND_ENUM: 3443289959bSAndrii Nakryiko for (i = 0, e = btf_enum(t); i < vlen; i++, e++) { 3453289959bSAndrii Nakryiko e->name_off = bswap_32(e->name_off); 3463289959bSAndrii Nakryiko e->val = bswap_32(e->val); 3473289959bSAndrii Nakryiko } 3483289959bSAndrii Nakryiko return 0; 3493289959bSAndrii Nakryiko case BTF_KIND_ARRAY: 3503289959bSAndrii Nakryiko a = btf_array(t); 3513289959bSAndrii Nakryiko a->type = bswap_32(a->type); 3523289959bSAndrii Nakryiko a->index_type = bswap_32(a->index_type); 3533289959bSAndrii Nakryiko a->nelems = bswap_32(a->nelems); 3543289959bSAndrii Nakryiko return 0; 3553289959bSAndrii Nakryiko case BTF_KIND_STRUCT: 3563289959bSAndrii Nakryiko case BTF_KIND_UNION: 3573289959bSAndrii Nakryiko for (i = 0, m = btf_members(t); i < vlen; i++, m++) { 3583289959bSAndrii Nakryiko m->name_off = bswap_32(m->name_off); 3593289959bSAndrii Nakryiko m->type = bswap_32(m->type); 3603289959bSAndrii Nakryiko m->offset = bswap_32(m->offset); 3613289959bSAndrii Nakryiko } 3623289959bSAndrii Nakryiko return 0; 3633289959bSAndrii Nakryiko case BTF_KIND_FUNC_PROTO: 3643289959bSAndrii Nakryiko for (i = 0, p = btf_params(t); i < vlen; i++, p++) { 3653289959bSAndrii Nakryiko p->name_off = bswap_32(p->name_off); 3663289959bSAndrii Nakryiko p->type = bswap_32(p->type); 3673289959bSAndrii Nakryiko } 3683289959bSAndrii Nakryiko return 0; 3693289959bSAndrii Nakryiko case BTF_KIND_VAR: 3703289959bSAndrii Nakryiko btf_var(t)->linkage = bswap_32(btf_var(t)->linkage); 3713289959bSAndrii Nakryiko return 0; 3723289959bSAndrii Nakryiko case BTF_KIND_DATASEC: 3733289959bSAndrii Nakryiko for (i = 0, v = btf_var_secinfos(t); i < vlen; i++, v++) { 3743289959bSAndrii Nakryiko v->type = bswap_32(v->type); 3753289959bSAndrii Nakryiko v->offset = bswap_32(v->offset); 3763289959bSAndrii Nakryiko v->size = bswap_32(v->size); 3773289959bSAndrii Nakryiko } 3783289959bSAndrii Nakryiko return 0; 3793289959bSAndrii Nakryiko default: 3803289959bSAndrii Nakryiko pr_debug("Unsupported BTF_KIND:%u\n", btf_kind(t)); 3813289959bSAndrii Nakryiko return -EINVAL; 3823289959bSAndrii Nakryiko } 3833289959bSAndrii Nakryiko } 3843289959bSAndrii Nakryiko 3858461ef8bSYonghong Song static int btf_parse_type_sec(struct btf *btf) 3868a138aedSMartin KaFai Lau { 3878a138aedSMartin KaFai Lau struct btf_header *hdr = btf->hdr; 388b8604247SAndrii Nakryiko void *next_type = btf->types_data; 389740e69c3SAndrii Nakryiko void *end_type = next_type + hdr->type_len; 390ba451366SAndrii Nakryiko int err, type_size; 391740e69c3SAndrii Nakryiko 3923289959bSAndrii Nakryiko while (next_type + sizeof(struct btf_type) <= end_type) { 3933289959bSAndrii Nakryiko if (btf->swapped_endian) 3943289959bSAndrii Nakryiko btf_bswap_type_base(next_type); 395740e69c3SAndrii Nakryiko 396740e69c3SAndrii Nakryiko type_size = btf_type_size(next_type); 397740e69c3SAndrii Nakryiko if (type_size < 0) 398740e69c3SAndrii Nakryiko return type_size; 3993289959bSAndrii Nakryiko if (next_type + type_size > end_type) { 400ba451366SAndrii Nakryiko pr_warn("BTF type [%d] is malformed\n", btf->start_id + btf->nr_types); 4013289959bSAndrii Nakryiko return -EINVAL; 4023289959bSAndrii Nakryiko } 4033289959bSAndrii Nakryiko 4043289959bSAndrii Nakryiko if (btf->swapped_endian && btf_bswap_type_rest(next_type)) 4053289959bSAndrii Nakryiko return -EINVAL; 4063289959bSAndrii Nakryiko 4073289959bSAndrii Nakryiko err = btf_add_type_idx_entry(btf, next_type - btf->types_data); 4083289959bSAndrii Nakryiko if (err) 4093289959bSAndrii Nakryiko return err; 410740e69c3SAndrii Nakryiko 411740e69c3SAndrii Nakryiko next_type += type_size; 412740e69c3SAndrii Nakryiko btf->nr_types++; 4138a138aedSMartin KaFai Lau } 4148a138aedSMartin KaFai Lau 4153289959bSAndrii Nakryiko if (next_type != end_type) { 4163289959bSAndrii Nakryiko pr_warn("BTF types data is malformed\n"); 4173289959bSAndrii Nakryiko return -EINVAL; 4183289959bSAndrii Nakryiko } 4193289959bSAndrii Nakryiko 4208a138aedSMartin KaFai Lau return 0; 4218a138aedSMartin KaFai Lau } 4228a138aedSMartin KaFai Lau 4239c651127SAndrii Nakryiko __u32 btf__get_nr_types(const struct btf *btf) 4249c651127SAndrii Nakryiko { 425ba451366SAndrii Nakryiko return btf->start_id + btf->nr_types - 1; 4269c651127SAndrii Nakryiko } 4279c651127SAndrii Nakryiko 4280cfdcd63SAndrii Nakryiko const struct btf *btf__base_btf(const struct btf *btf) 4290cfdcd63SAndrii Nakryiko { 4300cfdcd63SAndrii Nakryiko return btf->base_btf; 4310cfdcd63SAndrii Nakryiko } 4320cfdcd63SAndrii Nakryiko 433740e69c3SAndrii Nakryiko /* internal helper returning non-const pointer to a type */ 434e14ef4bfSAndrii Nakryiko struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id) 435740e69c3SAndrii Nakryiko { 436740e69c3SAndrii Nakryiko if (type_id == 0) 437740e69c3SAndrii Nakryiko return &btf_void; 438ba451366SAndrii Nakryiko if (type_id < btf->start_id) 439ba451366SAndrii Nakryiko return btf_type_by_id(btf->base_btf, type_id); 440ba451366SAndrii Nakryiko return btf->types_data + btf->type_offs[type_id - btf->start_id]; 441740e69c3SAndrii Nakryiko } 442740e69c3SAndrii Nakryiko 44338d5d3b3SMartin KaFai Lau const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id) 4448a138aedSMartin KaFai Lau { 445ba451366SAndrii Nakryiko if (type_id >= btf->start_id + btf->nr_types) 446e9fc3ce9SAndrii Nakryiko return errno = EINVAL, NULL; 447740e69c3SAndrii Nakryiko return btf_type_by_id((struct btf *)btf, type_id); 4488a138aedSMartin KaFai Lau } 4498a138aedSMartin KaFai Lau 45044ad23dfSAndrii Nakryiko static int determine_ptr_size(const struct btf *btf) 45144ad23dfSAndrii Nakryiko { 45244ad23dfSAndrii Nakryiko const struct btf_type *t; 45344ad23dfSAndrii Nakryiko const char *name; 454ba451366SAndrii Nakryiko int i, n; 45544ad23dfSAndrii Nakryiko 456ba451366SAndrii Nakryiko if (btf->base_btf && btf->base_btf->ptr_sz > 0) 457ba451366SAndrii Nakryiko return btf->base_btf->ptr_sz; 458ba451366SAndrii Nakryiko 459ba451366SAndrii Nakryiko n = btf__get_nr_types(btf); 460ba451366SAndrii Nakryiko for (i = 1; i <= n; i++) { 46144ad23dfSAndrii Nakryiko t = btf__type_by_id(btf, i); 46244ad23dfSAndrii Nakryiko if (!btf_is_int(t)) 46344ad23dfSAndrii Nakryiko continue; 46444ad23dfSAndrii Nakryiko 46544ad23dfSAndrii Nakryiko name = btf__name_by_offset(btf, t->name_off); 46644ad23dfSAndrii Nakryiko if (!name) 46744ad23dfSAndrii Nakryiko continue; 46844ad23dfSAndrii Nakryiko 46944ad23dfSAndrii Nakryiko if (strcmp(name, "long int") == 0 || 47044ad23dfSAndrii Nakryiko strcmp(name, "long unsigned int") == 0) { 47144ad23dfSAndrii Nakryiko if (t->size != 4 && t->size != 8) 47244ad23dfSAndrii Nakryiko continue; 47344ad23dfSAndrii Nakryiko return t->size; 47444ad23dfSAndrii Nakryiko } 47544ad23dfSAndrii Nakryiko } 47644ad23dfSAndrii Nakryiko 47744ad23dfSAndrii Nakryiko return -1; 47844ad23dfSAndrii Nakryiko } 47944ad23dfSAndrii Nakryiko 48044ad23dfSAndrii Nakryiko static size_t btf_ptr_sz(const struct btf *btf) 48144ad23dfSAndrii Nakryiko { 48244ad23dfSAndrii Nakryiko if (!btf->ptr_sz) 48344ad23dfSAndrii Nakryiko ((struct btf *)btf)->ptr_sz = determine_ptr_size(btf); 48444ad23dfSAndrii Nakryiko return btf->ptr_sz < 0 ? sizeof(void *) : btf->ptr_sz; 48544ad23dfSAndrii Nakryiko } 48644ad23dfSAndrii Nakryiko 48744ad23dfSAndrii Nakryiko /* Return pointer size this BTF instance assumes. The size is heuristically 48844ad23dfSAndrii Nakryiko * determined by looking for 'long' or 'unsigned long' integer type and 48944ad23dfSAndrii Nakryiko * recording its size in bytes. If BTF type information doesn't have any such 49044ad23dfSAndrii Nakryiko * type, this function returns 0. In the latter case, native architecture's 49144ad23dfSAndrii Nakryiko * pointer size is assumed, so will be either 4 or 8, depending on 49244ad23dfSAndrii Nakryiko * architecture that libbpf was compiled for. It's possible to override 49344ad23dfSAndrii Nakryiko * guessed value by using btf__set_pointer_size() API. 49444ad23dfSAndrii Nakryiko */ 49544ad23dfSAndrii Nakryiko size_t btf__pointer_size(const struct btf *btf) 49644ad23dfSAndrii Nakryiko { 49744ad23dfSAndrii Nakryiko if (!btf->ptr_sz) 49844ad23dfSAndrii Nakryiko ((struct btf *)btf)->ptr_sz = determine_ptr_size(btf); 49944ad23dfSAndrii Nakryiko 50044ad23dfSAndrii Nakryiko if (btf->ptr_sz < 0) 50144ad23dfSAndrii Nakryiko /* not enough BTF type info to guess */ 50244ad23dfSAndrii Nakryiko return 0; 50344ad23dfSAndrii Nakryiko 50444ad23dfSAndrii Nakryiko return btf->ptr_sz; 50544ad23dfSAndrii Nakryiko } 50644ad23dfSAndrii Nakryiko 50744ad23dfSAndrii Nakryiko /* Override or set pointer size in bytes. Only values of 4 and 8 are 50844ad23dfSAndrii Nakryiko * supported. 50944ad23dfSAndrii Nakryiko */ 51044ad23dfSAndrii Nakryiko int btf__set_pointer_size(struct btf *btf, size_t ptr_sz) 51144ad23dfSAndrii Nakryiko { 51244ad23dfSAndrii Nakryiko if (ptr_sz != 4 && ptr_sz != 8) 513e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 51444ad23dfSAndrii Nakryiko btf->ptr_sz = ptr_sz; 51544ad23dfSAndrii Nakryiko return 0; 51644ad23dfSAndrii Nakryiko } 51744ad23dfSAndrii Nakryiko 5183289959bSAndrii Nakryiko static bool is_host_big_endian(void) 5193289959bSAndrii Nakryiko { 5203289959bSAndrii Nakryiko #if __BYTE_ORDER == __LITTLE_ENDIAN 5213289959bSAndrii Nakryiko return false; 5223289959bSAndrii Nakryiko #elif __BYTE_ORDER == __BIG_ENDIAN 5233289959bSAndrii Nakryiko return true; 5243289959bSAndrii Nakryiko #else 5253289959bSAndrii Nakryiko # error "Unrecognized __BYTE_ORDER__" 5263289959bSAndrii Nakryiko #endif 5273289959bSAndrii Nakryiko } 5283289959bSAndrii Nakryiko 5293289959bSAndrii Nakryiko enum btf_endianness btf__endianness(const struct btf *btf) 5303289959bSAndrii Nakryiko { 5313289959bSAndrii Nakryiko if (is_host_big_endian()) 5323289959bSAndrii Nakryiko return btf->swapped_endian ? BTF_LITTLE_ENDIAN : BTF_BIG_ENDIAN; 5333289959bSAndrii Nakryiko else 5343289959bSAndrii Nakryiko return btf->swapped_endian ? BTF_BIG_ENDIAN : BTF_LITTLE_ENDIAN; 5353289959bSAndrii Nakryiko } 5363289959bSAndrii Nakryiko 5373289959bSAndrii Nakryiko int btf__set_endianness(struct btf *btf, enum btf_endianness endian) 5383289959bSAndrii Nakryiko { 5393289959bSAndrii Nakryiko if (endian != BTF_LITTLE_ENDIAN && endian != BTF_BIG_ENDIAN) 540e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 5413289959bSAndrii Nakryiko 5423289959bSAndrii Nakryiko btf->swapped_endian = is_host_big_endian() != (endian == BTF_BIG_ENDIAN); 5433289959bSAndrii Nakryiko if (!btf->swapped_endian) { 5443289959bSAndrii Nakryiko free(btf->raw_data_swapped); 5453289959bSAndrii Nakryiko btf->raw_data_swapped = NULL; 5463289959bSAndrii Nakryiko } 5473289959bSAndrii Nakryiko return 0; 5483289959bSAndrii Nakryiko } 5493289959bSAndrii Nakryiko 5508a138aedSMartin KaFai Lau static bool btf_type_is_void(const struct btf_type *t) 5518a138aedSMartin KaFai Lau { 552b03bc685SAndrii Nakryiko return t == &btf_void || btf_is_fwd(t); 5538a138aedSMartin KaFai Lau } 5548a138aedSMartin KaFai Lau 5558a138aedSMartin KaFai Lau static bool btf_type_is_void_or_null(const struct btf_type *t) 5568a138aedSMartin KaFai Lau { 5578a138aedSMartin KaFai Lau return !t || btf_type_is_void(t); 5588a138aedSMartin KaFai Lau } 5598a138aedSMartin KaFai Lau 5608a138aedSMartin KaFai Lau #define MAX_RESOLVE_DEPTH 32 5618a138aedSMartin KaFai Lau 5625b891af7SMartin KaFai Lau __s64 btf__resolve_size(const struct btf *btf, __u32 type_id) 5638a138aedSMartin KaFai Lau { 5648a138aedSMartin KaFai Lau const struct btf_array *array; 5658a138aedSMartin KaFai Lau const struct btf_type *t; 5665b891af7SMartin KaFai Lau __u32 nelems = 1; 5675b891af7SMartin KaFai Lau __s64 size = -1; 5688a138aedSMartin KaFai Lau int i; 5698a138aedSMartin KaFai Lau 57092b57121SOkash Khawaja t = btf__type_by_id(btf, type_id); 571e9fc3ce9SAndrii Nakryiko for (i = 0; i < MAX_RESOLVE_DEPTH && !btf_type_is_void_or_null(t); i++) { 572b03bc685SAndrii Nakryiko switch (btf_kind(t)) { 57369eaab04SAndrii Nakryiko case BTF_KIND_INT: 57469eaab04SAndrii Nakryiko case BTF_KIND_STRUCT: 57569eaab04SAndrii Nakryiko case BTF_KIND_UNION: 57669eaab04SAndrii Nakryiko case BTF_KIND_ENUM: 5771713d68bSDaniel Borkmann case BTF_KIND_DATASEC: 57822541a9eSIlya Leoshkevich case BTF_KIND_FLOAT: 57969eaab04SAndrii Nakryiko size = t->size; 58069eaab04SAndrii Nakryiko goto done; 58169eaab04SAndrii Nakryiko case BTF_KIND_PTR: 58244ad23dfSAndrii Nakryiko size = btf_ptr_sz(btf); 58369eaab04SAndrii Nakryiko goto done; 5848a138aedSMartin KaFai Lau case BTF_KIND_TYPEDEF: 5858a138aedSMartin KaFai Lau case BTF_KIND_VOLATILE: 5868a138aedSMartin KaFai Lau case BTF_KIND_CONST: 5878a138aedSMartin KaFai Lau case BTF_KIND_RESTRICT: 5881713d68bSDaniel Borkmann case BTF_KIND_VAR: 5898a138aedSMartin KaFai Lau type_id = t->type; 5908a138aedSMartin KaFai Lau break; 5918a138aedSMartin KaFai Lau case BTF_KIND_ARRAY: 592b03bc685SAndrii Nakryiko array = btf_array(t); 5938a138aedSMartin KaFai Lau if (nelems && array->nelems > UINT32_MAX / nelems) 594e9fc3ce9SAndrii Nakryiko return libbpf_err(-E2BIG); 5958a138aedSMartin KaFai Lau nelems *= array->nelems; 5968a138aedSMartin KaFai Lau type_id = array->type; 5978a138aedSMartin KaFai Lau break; 5988a138aedSMartin KaFai Lau default: 599e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 6008a138aedSMartin KaFai Lau } 6018a138aedSMartin KaFai Lau 60292b57121SOkash Khawaja t = btf__type_by_id(btf, type_id); 6038a138aedSMartin KaFai Lau } 6048a138aedSMartin KaFai Lau 605994021a7SAndrii Nakryiko done: 6068a138aedSMartin KaFai Lau if (size < 0) 607e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 6088a138aedSMartin KaFai Lau if (nelems && size > UINT32_MAX / nelems) 609e9fc3ce9SAndrii Nakryiko return libbpf_err(-E2BIG); 6108a138aedSMartin KaFai Lau 6118a138aedSMartin KaFai Lau return nelems * size; 6128a138aedSMartin KaFai Lau } 6138a138aedSMartin KaFai Lau 6143d208f4cSAndrii Nakryiko int btf__align_of(const struct btf *btf, __u32 id) 6153d208f4cSAndrii Nakryiko { 6163d208f4cSAndrii Nakryiko const struct btf_type *t = btf__type_by_id(btf, id); 6173d208f4cSAndrii Nakryiko __u16 kind = btf_kind(t); 6183d208f4cSAndrii Nakryiko 6193d208f4cSAndrii Nakryiko switch (kind) { 6203d208f4cSAndrii Nakryiko case BTF_KIND_INT: 6213d208f4cSAndrii Nakryiko case BTF_KIND_ENUM: 62222541a9eSIlya Leoshkevich case BTF_KIND_FLOAT: 62344ad23dfSAndrii Nakryiko return min(btf_ptr_sz(btf), (size_t)t->size); 6243d208f4cSAndrii Nakryiko case BTF_KIND_PTR: 62544ad23dfSAndrii Nakryiko return btf_ptr_sz(btf); 6263d208f4cSAndrii Nakryiko case BTF_KIND_TYPEDEF: 6273d208f4cSAndrii Nakryiko case BTF_KIND_VOLATILE: 6283d208f4cSAndrii Nakryiko case BTF_KIND_CONST: 6293d208f4cSAndrii Nakryiko case BTF_KIND_RESTRICT: 6303d208f4cSAndrii Nakryiko return btf__align_of(btf, t->type); 6313d208f4cSAndrii Nakryiko case BTF_KIND_ARRAY: 6323d208f4cSAndrii Nakryiko return btf__align_of(btf, btf_array(t)->type); 6333d208f4cSAndrii Nakryiko case BTF_KIND_STRUCT: 6343d208f4cSAndrii Nakryiko case BTF_KIND_UNION: { 6353d208f4cSAndrii Nakryiko const struct btf_member *m = btf_members(t); 6363d208f4cSAndrii Nakryiko __u16 vlen = btf_vlen(t); 637a79ac2d1SPrashant Bhole int i, max_align = 1, align; 6383d208f4cSAndrii Nakryiko 6393d208f4cSAndrii Nakryiko for (i = 0; i < vlen; i++, m++) { 640a79ac2d1SPrashant Bhole align = btf__align_of(btf, m->type); 641a79ac2d1SPrashant Bhole if (align <= 0) 642e9fc3ce9SAndrii Nakryiko return libbpf_err(align); 643a79ac2d1SPrashant Bhole max_align = max(max_align, align); 6443d208f4cSAndrii Nakryiko } 6453d208f4cSAndrii Nakryiko 646a79ac2d1SPrashant Bhole return max_align; 6473d208f4cSAndrii Nakryiko } 6483d208f4cSAndrii Nakryiko default: 6493d208f4cSAndrii Nakryiko pr_warn("unsupported BTF_KIND:%u\n", btf_kind(t)); 650e9fc3ce9SAndrii Nakryiko return errno = EINVAL, 0; 6513d208f4cSAndrii Nakryiko } 6523d208f4cSAndrii Nakryiko } 6533d208f4cSAndrii Nakryiko 65492b57121SOkash Khawaja int btf__resolve_type(const struct btf *btf, __u32 type_id) 65592b57121SOkash Khawaja { 65692b57121SOkash Khawaja const struct btf_type *t; 65792b57121SOkash Khawaja int depth = 0; 65892b57121SOkash Khawaja 65992b57121SOkash Khawaja t = btf__type_by_id(btf, type_id); 66092b57121SOkash Khawaja while (depth < MAX_RESOLVE_DEPTH && 66192b57121SOkash Khawaja !btf_type_is_void_or_null(t) && 662b03bc685SAndrii Nakryiko (btf_is_mod(t) || btf_is_typedef(t) || btf_is_var(t))) { 66392b57121SOkash Khawaja type_id = t->type; 66492b57121SOkash Khawaja t = btf__type_by_id(btf, type_id); 66592b57121SOkash Khawaja depth++; 66692b57121SOkash Khawaja } 66792b57121SOkash Khawaja 66892b57121SOkash Khawaja if (depth == MAX_RESOLVE_DEPTH || btf_type_is_void_or_null(t)) 669e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 67092b57121SOkash Khawaja 67192b57121SOkash Khawaja return type_id; 67292b57121SOkash Khawaja } 67392b57121SOkash Khawaja 6745b891af7SMartin KaFai Lau __s32 btf__find_by_name(const struct btf *btf, const char *type_name) 6758a138aedSMartin KaFai Lau { 676de91e631SAlan Maguire __u32 i, nr_types = btf__get_nr_types(btf); 6778a138aedSMartin KaFai Lau 6788a138aedSMartin KaFai Lau if (!strcmp(type_name, "void")) 6798a138aedSMartin KaFai Lau return 0; 6808a138aedSMartin KaFai Lau 681de91e631SAlan Maguire for (i = 1; i <= nr_types; i++) { 682740e69c3SAndrii Nakryiko const struct btf_type *t = btf__type_by_id(btf, i); 68392b57121SOkash Khawaja const char *name = btf__name_by_offset(btf, t->name_off); 6848a138aedSMartin KaFai Lau 6858a138aedSMartin KaFai Lau if (name && !strcmp(type_name, name)) 6868a138aedSMartin KaFai Lau return i; 6878a138aedSMartin KaFai Lau } 6888a138aedSMartin KaFai Lau 689e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOENT); 6908a138aedSMartin KaFai Lau } 6918a138aedSMartin KaFai Lau 6921442e287SAlexei Starovoitov __s32 btf__find_by_name_kind(const struct btf *btf, const char *type_name, 6931442e287SAlexei Starovoitov __u32 kind) 6941442e287SAlexei Starovoitov { 695de91e631SAlan Maguire __u32 i, nr_types = btf__get_nr_types(btf); 6961442e287SAlexei Starovoitov 6971442e287SAlexei Starovoitov if (kind == BTF_KIND_UNKN || !strcmp(type_name, "void")) 6981442e287SAlexei Starovoitov return 0; 6991442e287SAlexei Starovoitov 700de91e631SAlan Maguire for (i = 1; i <= nr_types; i++) { 701740e69c3SAndrii Nakryiko const struct btf_type *t = btf__type_by_id(btf, i); 7021442e287SAlexei Starovoitov const char *name; 7031442e287SAlexei Starovoitov 7041442e287SAlexei Starovoitov if (btf_kind(t) != kind) 7051442e287SAlexei Starovoitov continue; 7061442e287SAlexei Starovoitov name = btf__name_by_offset(btf, t->name_off); 7071442e287SAlexei Starovoitov if (name && !strcmp(type_name, name)) 7081442e287SAlexei Starovoitov return i; 7091442e287SAlexei Starovoitov } 7101442e287SAlexei Starovoitov 711e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOENT); 7121442e287SAlexei Starovoitov } 7131442e287SAlexei Starovoitov 714919d2b1dSAndrii Nakryiko static bool btf_is_modifiable(const struct btf *btf) 715919d2b1dSAndrii Nakryiko { 716919d2b1dSAndrii Nakryiko return (void *)btf->hdr != btf->raw_data; 717919d2b1dSAndrii Nakryiko } 718919d2b1dSAndrii Nakryiko 7198a138aedSMartin KaFai Lau void btf__free(struct btf *btf) 7208a138aedSMartin KaFai Lau { 72150450fc7SAndrii Nakryiko if (IS_ERR_OR_NULL(btf)) 7228a138aedSMartin KaFai Lau return; 7238a138aedSMartin KaFai Lau 72481372e12SAndrii Nakryiko if (btf->fd >= 0) 7258a138aedSMartin KaFai Lau close(btf->fd); 7268a138aedSMartin KaFai Lau 727919d2b1dSAndrii Nakryiko if (btf_is_modifiable(btf)) { 728919d2b1dSAndrii Nakryiko /* if BTF was modified after loading, it will have a split 729919d2b1dSAndrii Nakryiko * in-memory representation for header, types, and strings 730919d2b1dSAndrii Nakryiko * sections, so we need to free all of them individually. It 731919d2b1dSAndrii Nakryiko * might still have a cached contiguous raw data present, 732919d2b1dSAndrii Nakryiko * which will be unconditionally freed below. 733919d2b1dSAndrii Nakryiko */ 734919d2b1dSAndrii Nakryiko free(btf->hdr); 735919d2b1dSAndrii Nakryiko free(btf->types_data); 73690d76d3eSAndrii Nakryiko strset__free(btf->strs_set); 737919d2b1dSAndrii Nakryiko } 738b8604247SAndrii Nakryiko free(btf->raw_data); 7393289959bSAndrii Nakryiko free(btf->raw_data_swapped); 740740e69c3SAndrii Nakryiko free(btf->type_offs); 7418a138aedSMartin KaFai Lau free(btf); 7428a138aedSMartin KaFai Lau } 7438a138aedSMartin KaFai Lau 744ba451366SAndrii Nakryiko static struct btf *btf_new_empty(struct btf *base_btf) 745a871b043SAndrii Nakryiko { 746a871b043SAndrii Nakryiko struct btf *btf; 747a871b043SAndrii Nakryiko 748a871b043SAndrii Nakryiko btf = calloc(1, sizeof(*btf)); 749a871b043SAndrii Nakryiko if (!btf) 750a871b043SAndrii Nakryiko return ERR_PTR(-ENOMEM); 7513289959bSAndrii Nakryiko 752ba451366SAndrii Nakryiko btf->nr_types = 0; 753ba451366SAndrii Nakryiko btf->start_id = 1; 754ba451366SAndrii Nakryiko btf->start_str_off = 0; 755a871b043SAndrii Nakryiko btf->fd = -1; 756a871b043SAndrii Nakryiko btf->ptr_sz = sizeof(void *); 7573289959bSAndrii Nakryiko btf->swapped_endian = false; 758a871b043SAndrii Nakryiko 759ba451366SAndrii Nakryiko if (base_btf) { 760ba451366SAndrii Nakryiko btf->base_btf = base_btf; 761ba451366SAndrii Nakryiko btf->start_id = btf__get_nr_types(base_btf) + 1; 762ba451366SAndrii Nakryiko btf->start_str_off = base_btf->hdr->str_len; 763ba451366SAndrii Nakryiko } 764ba451366SAndrii Nakryiko 765a871b043SAndrii Nakryiko /* +1 for empty string at offset 0 */ 766ba451366SAndrii Nakryiko btf->raw_size = sizeof(struct btf_header) + (base_btf ? 0 : 1); 767a871b043SAndrii Nakryiko btf->raw_data = calloc(1, btf->raw_size); 768a871b043SAndrii Nakryiko if (!btf->raw_data) { 769a871b043SAndrii Nakryiko free(btf); 770a871b043SAndrii Nakryiko return ERR_PTR(-ENOMEM); 771a871b043SAndrii Nakryiko } 772a871b043SAndrii Nakryiko 773a871b043SAndrii Nakryiko btf->hdr = btf->raw_data; 774a871b043SAndrii Nakryiko btf->hdr->hdr_len = sizeof(struct btf_header); 775a871b043SAndrii Nakryiko btf->hdr->magic = BTF_MAGIC; 776a871b043SAndrii Nakryiko btf->hdr->version = BTF_VERSION; 777a871b043SAndrii Nakryiko 778a871b043SAndrii Nakryiko btf->types_data = btf->raw_data + btf->hdr->hdr_len; 779a871b043SAndrii Nakryiko btf->strs_data = btf->raw_data + btf->hdr->hdr_len; 780ba451366SAndrii Nakryiko btf->hdr->str_len = base_btf ? 0 : 1; /* empty string at offset 0 */ 781a871b043SAndrii Nakryiko 782a871b043SAndrii Nakryiko return btf; 783a871b043SAndrii Nakryiko } 784a871b043SAndrii Nakryiko 785ba451366SAndrii Nakryiko struct btf *btf__new_empty(void) 786ba451366SAndrii Nakryiko { 787e9fc3ce9SAndrii Nakryiko return libbpf_ptr(btf_new_empty(NULL)); 788ba451366SAndrii Nakryiko } 789ba451366SAndrii Nakryiko 790ba451366SAndrii Nakryiko struct btf *btf__new_empty_split(struct btf *base_btf) 791ba451366SAndrii Nakryiko { 792e9fc3ce9SAndrii Nakryiko return libbpf_ptr(btf_new_empty(base_btf)); 793ba451366SAndrii Nakryiko } 794ba451366SAndrii Nakryiko 795ba451366SAndrii Nakryiko static struct btf *btf_new(const void *data, __u32 size, struct btf *base_btf) 7968a138aedSMartin KaFai Lau { 7978a138aedSMartin KaFai Lau struct btf *btf; 7988a138aedSMartin KaFai Lau int err; 7998a138aedSMartin KaFai Lau 8008a138aedSMartin KaFai Lau btf = calloc(1, sizeof(struct btf)); 8018a138aedSMartin KaFai Lau if (!btf) 8028a138aedSMartin KaFai Lau return ERR_PTR(-ENOMEM); 8038a138aedSMartin KaFai Lau 804ba451366SAndrii Nakryiko btf->nr_types = 0; 805ba451366SAndrii Nakryiko btf->start_id = 1; 806ba451366SAndrii Nakryiko btf->start_str_off = 0; 807ba451366SAndrii Nakryiko 808ba451366SAndrii Nakryiko if (base_btf) { 809ba451366SAndrii Nakryiko btf->base_btf = base_btf; 810ba451366SAndrii Nakryiko btf->start_id = btf__get_nr_types(base_btf) + 1; 811ba451366SAndrii Nakryiko btf->start_str_off = base_btf->hdr->str_len; 812ba451366SAndrii Nakryiko } 813ba451366SAndrii Nakryiko 814b8604247SAndrii Nakryiko btf->raw_data = malloc(size); 815b8604247SAndrii Nakryiko if (!btf->raw_data) { 8168a138aedSMartin KaFai Lau err = -ENOMEM; 8178a138aedSMartin KaFai Lau goto done; 8188a138aedSMartin KaFai Lau } 819b8604247SAndrii Nakryiko memcpy(btf->raw_data, data, size); 820b8604247SAndrii Nakryiko btf->raw_size = size; 8218a138aedSMartin KaFai Lau 822b8604247SAndrii Nakryiko btf->hdr = btf->raw_data; 8238461ef8bSYonghong Song err = btf_parse_hdr(btf); 8248a138aedSMartin KaFai Lau if (err) 8258a138aedSMartin KaFai Lau goto done; 8268a138aedSMartin KaFai Lau 827b8604247SAndrii Nakryiko btf->strs_data = btf->raw_data + btf->hdr->hdr_len + btf->hdr->str_off; 828b8604247SAndrii Nakryiko btf->types_data = btf->raw_data + btf->hdr->hdr_len + btf->hdr->type_off; 8298a138aedSMartin KaFai Lau 830b8604247SAndrii Nakryiko err = btf_parse_str_sec(btf); 831b8604247SAndrii Nakryiko err = err ?: btf_parse_type_sec(btf); 8323289959bSAndrii Nakryiko if (err) 8333289959bSAndrii Nakryiko goto done; 8343289959bSAndrii Nakryiko 8353289959bSAndrii Nakryiko btf->fd = -1; 8368a138aedSMartin KaFai Lau 8378a138aedSMartin KaFai Lau done: 8388a138aedSMartin KaFai Lau if (err) { 8398a138aedSMartin KaFai Lau btf__free(btf); 8408a138aedSMartin KaFai Lau return ERR_PTR(err); 8418a138aedSMartin KaFai Lau } 8428a138aedSMartin KaFai Lau 8438a138aedSMartin KaFai Lau return btf; 8448a138aedSMartin KaFai Lau } 8458a138aedSMartin KaFai Lau 846ba451366SAndrii Nakryiko struct btf *btf__new(const void *data, __u32 size) 847ba451366SAndrii Nakryiko { 848e9fc3ce9SAndrii Nakryiko return libbpf_ptr(btf_new(data, size, NULL)); 849ba451366SAndrii Nakryiko } 850ba451366SAndrii Nakryiko 851ba451366SAndrii Nakryiko static struct btf *btf_parse_elf(const char *path, struct btf *base_btf, 852ba451366SAndrii Nakryiko struct btf_ext **btf_ext) 853e6c64855SAndrii Nakryiko { 854e6c64855SAndrii Nakryiko Elf_Data *btf_data = NULL, *btf_ext_data = NULL; 855e6c64855SAndrii Nakryiko int err = 0, fd = -1, idx = 0; 856e6c64855SAndrii Nakryiko struct btf *btf = NULL; 857e6c64855SAndrii Nakryiko Elf_Scn *scn = NULL; 858e6c64855SAndrii Nakryiko Elf *elf = NULL; 859e6c64855SAndrii Nakryiko GElf_Ehdr ehdr; 8606095d5a2SJiri Olsa size_t shstrndx; 861e6c64855SAndrii Nakryiko 862e6c64855SAndrii Nakryiko if (elf_version(EV_CURRENT) == EV_NONE) { 863be18010eSKefeng Wang pr_warn("failed to init libelf for %s\n", path); 864e6c64855SAndrii Nakryiko return ERR_PTR(-LIBBPF_ERRNO__LIBELF); 865e6c64855SAndrii Nakryiko } 866e6c64855SAndrii Nakryiko 867e6c64855SAndrii Nakryiko fd = open(path, O_RDONLY); 868e6c64855SAndrii Nakryiko if (fd < 0) { 869e6c64855SAndrii Nakryiko err = -errno; 870be18010eSKefeng Wang pr_warn("failed to open %s: %s\n", path, strerror(errno)); 871e6c64855SAndrii Nakryiko return ERR_PTR(err); 872e6c64855SAndrii Nakryiko } 873e6c64855SAndrii Nakryiko 874e6c64855SAndrii Nakryiko err = -LIBBPF_ERRNO__FORMAT; 875e6c64855SAndrii Nakryiko 876e6c64855SAndrii Nakryiko elf = elf_begin(fd, ELF_C_READ, NULL); 877e6c64855SAndrii Nakryiko if (!elf) { 878be18010eSKefeng Wang pr_warn("failed to open %s as ELF file\n", path); 879e6c64855SAndrii Nakryiko goto done; 880e6c64855SAndrii Nakryiko } 881e6c64855SAndrii Nakryiko if (!gelf_getehdr(elf, &ehdr)) { 882be18010eSKefeng Wang pr_warn("failed to get EHDR from %s\n", path); 883e6c64855SAndrii Nakryiko goto done; 884e6c64855SAndrii Nakryiko } 8856095d5a2SJiri Olsa 8866095d5a2SJiri Olsa if (elf_getshdrstrndx(elf, &shstrndx)) { 8876095d5a2SJiri Olsa pr_warn("failed to get section names section index for %s\n", 8886095d5a2SJiri Olsa path); 8896095d5a2SJiri Olsa goto done; 8906095d5a2SJiri Olsa } 8916095d5a2SJiri Olsa 8926095d5a2SJiri Olsa if (!elf_rawdata(elf_getscn(elf, shstrndx), NULL)) { 893be18010eSKefeng Wang pr_warn("failed to get e_shstrndx from %s\n", path); 894e6c64855SAndrii Nakryiko goto done; 895e6c64855SAndrii Nakryiko } 896e6c64855SAndrii Nakryiko 897e6c64855SAndrii Nakryiko while ((scn = elf_nextscn(elf, scn)) != NULL) { 898e6c64855SAndrii Nakryiko GElf_Shdr sh; 899e6c64855SAndrii Nakryiko char *name; 900e6c64855SAndrii Nakryiko 901e6c64855SAndrii Nakryiko idx++; 902e6c64855SAndrii Nakryiko if (gelf_getshdr(scn, &sh) != &sh) { 903be18010eSKefeng Wang pr_warn("failed to get section(%d) header from %s\n", 904e6c64855SAndrii Nakryiko idx, path); 905e6c64855SAndrii Nakryiko goto done; 906e6c64855SAndrii Nakryiko } 9076095d5a2SJiri Olsa name = elf_strptr(elf, shstrndx, sh.sh_name); 908e6c64855SAndrii Nakryiko if (!name) { 909be18010eSKefeng Wang pr_warn("failed to get section(%d) name from %s\n", 910e6c64855SAndrii Nakryiko idx, path); 911e6c64855SAndrii Nakryiko goto done; 912e6c64855SAndrii Nakryiko } 913e6c64855SAndrii Nakryiko if (strcmp(name, BTF_ELF_SEC) == 0) { 914e6c64855SAndrii Nakryiko btf_data = elf_getdata(scn, 0); 915e6c64855SAndrii Nakryiko if (!btf_data) { 916be18010eSKefeng Wang pr_warn("failed to get section(%d, %s) data from %s\n", 917e6c64855SAndrii Nakryiko idx, name, path); 918e6c64855SAndrii Nakryiko goto done; 919e6c64855SAndrii Nakryiko } 920e6c64855SAndrii Nakryiko continue; 921e6c64855SAndrii Nakryiko } else if (btf_ext && strcmp(name, BTF_EXT_ELF_SEC) == 0) { 922e6c64855SAndrii Nakryiko btf_ext_data = elf_getdata(scn, 0); 923e6c64855SAndrii Nakryiko if (!btf_ext_data) { 924be18010eSKefeng Wang pr_warn("failed to get section(%d, %s) data from %s\n", 925e6c64855SAndrii Nakryiko idx, name, path); 926e6c64855SAndrii Nakryiko goto done; 927e6c64855SAndrii Nakryiko } 928e6c64855SAndrii Nakryiko continue; 929e6c64855SAndrii Nakryiko } 930e6c64855SAndrii Nakryiko } 931e6c64855SAndrii Nakryiko 932e6c64855SAndrii Nakryiko err = 0; 933e6c64855SAndrii Nakryiko 934e6c64855SAndrii Nakryiko if (!btf_data) { 935e6c64855SAndrii Nakryiko err = -ENOENT; 936e6c64855SAndrii Nakryiko goto done; 937e6c64855SAndrii Nakryiko } 938ba451366SAndrii Nakryiko btf = btf_new(btf_data->d_buf, btf_data->d_size, base_btf); 939e9fc3ce9SAndrii Nakryiko err = libbpf_get_error(btf); 940e9fc3ce9SAndrii Nakryiko if (err) 941e6c64855SAndrii Nakryiko goto done; 942e6c64855SAndrii Nakryiko 94344ad23dfSAndrii Nakryiko switch (gelf_getclass(elf)) { 94444ad23dfSAndrii Nakryiko case ELFCLASS32: 94544ad23dfSAndrii Nakryiko btf__set_pointer_size(btf, 4); 94644ad23dfSAndrii Nakryiko break; 94744ad23dfSAndrii Nakryiko case ELFCLASS64: 94844ad23dfSAndrii Nakryiko btf__set_pointer_size(btf, 8); 94944ad23dfSAndrii Nakryiko break; 95044ad23dfSAndrii Nakryiko default: 95144ad23dfSAndrii Nakryiko pr_warn("failed to get ELF class (bitness) for %s\n", path); 95244ad23dfSAndrii Nakryiko break; 95344ad23dfSAndrii Nakryiko } 95444ad23dfSAndrii Nakryiko 955e6c64855SAndrii Nakryiko if (btf_ext && btf_ext_data) { 956e9fc3ce9SAndrii Nakryiko *btf_ext = btf_ext__new(btf_ext_data->d_buf, btf_ext_data->d_size); 957e9fc3ce9SAndrii Nakryiko err = libbpf_get_error(*btf_ext); 958e9fc3ce9SAndrii Nakryiko if (err) 959e6c64855SAndrii Nakryiko goto done; 960e6c64855SAndrii Nakryiko } else if (btf_ext) { 961e6c64855SAndrii Nakryiko *btf_ext = NULL; 962e6c64855SAndrii Nakryiko } 963e6c64855SAndrii Nakryiko done: 964e6c64855SAndrii Nakryiko if (elf) 965e6c64855SAndrii Nakryiko elf_end(elf); 966e6c64855SAndrii Nakryiko close(fd); 967e6c64855SAndrii Nakryiko 968e9fc3ce9SAndrii Nakryiko if (!err) 969e6c64855SAndrii Nakryiko return btf; 970e9fc3ce9SAndrii Nakryiko 971e9fc3ce9SAndrii Nakryiko if (btf_ext) 972e9fc3ce9SAndrii Nakryiko btf_ext__free(*btf_ext); 973e6c64855SAndrii Nakryiko btf__free(btf); 974e9fc3ce9SAndrii Nakryiko 975e6c64855SAndrii Nakryiko return ERR_PTR(err); 976e6c64855SAndrii Nakryiko } 977e6c64855SAndrii Nakryiko 978ba451366SAndrii Nakryiko struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext) 979ba451366SAndrii Nakryiko { 980e9fc3ce9SAndrii Nakryiko return libbpf_ptr(btf_parse_elf(path, NULL, btf_ext)); 981ba451366SAndrii Nakryiko } 982ba451366SAndrii Nakryiko 983ba451366SAndrii Nakryiko struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf) 984ba451366SAndrii Nakryiko { 985e9fc3ce9SAndrii Nakryiko return libbpf_ptr(btf_parse_elf(path, base_btf, NULL)); 986ba451366SAndrii Nakryiko } 987ba451366SAndrii Nakryiko 988ba451366SAndrii Nakryiko static struct btf *btf_parse_raw(const char *path, struct btf *base_btf) 98994a1feddSAndrii Nakryiko { 990932ac54aSDaniel T. Lee struct btf *btf = NULL; 99194a1feddSAndrii Nakryiko void *data = NULL; 99294a1feddSAndrii Nakryiko FILE *f = NULL; 99394a1feddSAndrii Nakryiko __u16 magic; 99494a1feddSAndrii Nakryiko int err = 0; 99594a1feddSAndrii Nakryiko long sz; 99694a1feddSAndrii Nakryiko 99794a1feddSAndrii Nakryiko f = fopen(path, "rb"); 99894a1feddSAndrii Nakryiko if (!f) { 99994a1feddSAndrii Nakryiko err = -errno; 100094a1feddSAndrii Nakryiko goto err_out; 100194a1feddSAndrii Nakryiko } 100294a1feddSAndrii Nakryiko 100394a1feddSAndrii Nakryiko /* check BTF magic */ 100494a1feddSAndrii Nakryiko if (fread(&magic, 1, sizeof(magic), f) < sizeof(magic)) { 100594a1feddSAndrii Nakryiko err = -EIO; 100694a1feddSAndrii Nakryiko goto err_out; 100794a1feddSAndrii Nakryiko } 10083289959bSAndrii Nakryiko if (magic != BTF_MAGIC && magic != bswap_16(BTF_MAGIC)) { 100994a1feddSAndrii Nakryiko /* definitely not a raw BTF */ 101094a1feddSAndrii Nakryiko err = -EPROTO; 101194a1feddSAndrii Nakryiko goto err_out; 101294a1feddSAndrii Nakryiko } 101394a1feddSAndrii Nakryiko 101494a1feddSAndrii Nakryiko /* get file size */ 101594a1feddSAndrii Nakryiko if (fseek(f, 0, SEEK_END)) { 101694a1feddSAndrii Nakryiko err = -errno; 101794a1feddSAndrii Nakryiko goto err_out; 101894a1feddSAndrii Nakryiko } 101994a1feddSAndrii Nakryiko sz = ftell(f); 102094a1feddSAndrii Nakryiko if (sz < 0) { 102194a1feddSAndrii Nakryiko err = -errno; 102294a1feddSAndrii Nakryiko goto err_out; 102394a1feddSAndrii Nakryiko } 102494a1feddSAndrii Nakryiko /* rewind to the start */ 102594a1feddSAndrii Nakryiko if (fseek(f, 0, SEEK_SET)) { 102694a1feddSAndrii Nakryiko err = -errno; 102794a1feddSAndrii Nakryiko goto err_out; 102894a1feddSAndrii Nakryiko } 102994a1feddSAndrii Nakryiko 103094a1feddSAndrii Nakryiko /* pre-alloc memory and read all of BTF data */ 103194a1feddSAndrii Nakryiko data = malloc(sz); 103294a1feddSAndrii Nakryiko if (!data) { 103394a1feddSAndrii Nakryiko err = -ENOMEM; 103494a1feddSAndrii Nakryiko goto err_out; 103594a1feddSAndrii Nakryiko } 103694a1feddSAndrii Nakryiko if (fread(data, 1, sz, f) < sz) { 103794a1feddSAndrii Nakryiko err = -EIO; 103894a1feddSAndrii Nakryiko goto err_out; 103994a1feddSAndrii Nakryiko } 104094a1feddSAndrii Nakryiko 104194a1feddSAndrii Nakryiko /* finally parse BTF data */ 1042ba451366SAndrii Nakryiko btf = btf_new(data, sz, base_btf); 104394a1feddSAndrii Nakryiko 104494a1feddSAndrii Nakryiko err_out: 104594a1feddSAndrii Nakryiko free(data); 104694a1feddSAndrii Nakryiko if (f) 104794a1feddSAndrii Nakryiko fclose(f); 104894a1feddSAndrii Nakryiko return err ? ERR_PTR(err) : btf; 104994a1feddSAndrii Nakryiko } 105094a1feddSAndrii Nakryiko 1051ba451366SAndrii Nakryiko struct btf *btf__parse_raw(const char *path) 1052ba451366SAndrii Nakryiko { 1053e9fc3ce9SAndrii Nakryiko return libbpf_ptr(btf_parse_raw(path, NULL)); 1054ba451366SAndrii Nakryiko } 1055ba451366SAndrii Nakryiko 1056ba451366SAndrii Nakryiko struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf) 1057ba451366SAndrii Nakryiko { 1058e9fc3ce9SAndrii Nakryiko return libbpf_ptr(btf_parse_raw(path, base_btf)); 1059ba451366SAndrii Nakryiko } 1060ba451366SAndrii Nakryiko 1061ba451366SAndrii Nakryiko static struct btf *btf_parse(const char *path, struct btf *base_btf, struct btf_ext **btf_ext) 106294a1feddSAndrii Nakryiko { 106394a1feddSAndrii Nakryiko struct btf *btf; 1064e9fc3ce9SAndrii Nakryiko int err; 106594a1feddSAndrii Nakryiko 106694a1feddSAndrii Nakryiko if (btf_ext) 106794a1feddSAndrii Nakryiko *btf_ext = NULL; 106894a1feddSAndrii Nakryiko 1069ba451366SAndrii Nakryiko btf = btf_parse_raw(path, base_btf); 1070e9fc3ce9SAndrii Nakryiko err = libbpf_get_error(btf); 1071e9fc3ce9SAndrii Nakryiko if (!err) 107294a1feddSAndrii Nakryiko return btf; 1073e9fc3ce9SAndrii Nakryiko if (err != -EPROTO) 1074e9fc3ce9SAndrii Nakryiko return ERR_PTR(err); 1075ba451366SAndrii Nakryiko return btf_parse_elf(path, base_btf, btf_ext); 1076ba451366SAndrii Nakryiko } 1077ba451366SAndrii Nakryiko 1078ba451366SAndrii Nakryiko struct btf *btf__parse(const char *path, struct btf_ext **btf_ext) 1079ba451366SAndrii Nakryiko { 1080e9fc3ce9SAndrii Nakryiko return libbpf_ptr(btf_parse(path, NULL, btf_ext)); 1081ba451366SAndrii Nakryiko } 1082ba451366SAndrii Nakryiko 1083ba451366SAndrii Nakryiko struct btf *btf__parse_split(const char *path, struct btf *base_btf) 1084ba451366SAndrii Nakryiko { 1085e9fc3ce9SAndrii Nakryiko return libbpf_ptr(btf_parse(path, base_btf, NULL)); 108694a1feddSAndrii Nakryiko } 108794a1feddSAndrii Nakryiko 10881713d68bSDaniel Borkmann static int compare_vsi_off(const void *_a, const void *_b) 10891713d68bSDaniel Borkmann { 10901713d68bSDaniel Borkmann const struct btf_var_secinfo *a = _a; 10911713d68bSDaniel Borkmann const struct btf_var_secinfo *b = _b; 10921713d68bSDaniel Borkmann 10931713d68bSDaniel Borkmann return a->offset - b->offset; 10941713d68bSDaniel Borkmann } 10951713d68bSDaniel Borkmann 10961713d68bSDaniel Borkmann static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf, 10971713d68bSDaniel Borkmann struct btf_type *t) 10981713d68bSDaniel Borkmann { 1099b03bc685SAndrii Nakryiko __u32 size = 0, off = 0, i, vars = btf_vlen(t); 11001713d68bSDaniel Borkmann const char *name = btf__name_by_offset(btf, t->name_off); 11011713d68bSDaniel Borkmann const struct btf_type *t_var; 11021713d68bSDaniel Borkmann struct btf_var_secinfo *vsi; 1103b03bc685SAndrii Nakryiko const struct btf_var *var; 11041713d68bSDaniel Borkmann int ret; 11051713d68bSDaniel Borkmann 11061713d68bSDaniel Borkmann if (!name) { 11071713d68bSDaniel Borkmann pr_debug("No name found in string section for DATASEC kind.\n"); 11081713d68bSDaniel Borkmann return -ENOENT; 11091713d68bSDaniel Borkmann } 11101713d68bSDaniel Borkmann 1111166750bcSAndrii Nakryiko /* .extern datasec size and var offsets were set correctly during 1112166750bcSAndrii Nakryiko * extern collection step, so just skip straight to sorting variables 1113166750bcSAndrii Nakryiko */ 1114166750bcSAndrii Nakryiko if (t->size) 1115166750bcSAndrii Nakryiko goto sort_vars; 1116166750bcSAndrii Nakryiko 11171713d68bSDaniel Borkmann ret = bpf_object__section_size(obj, name, &size); 11181713d68bSDaniel Borkmann if (ret || !size || (t->size && t->size != size)) { 11191713d68bSDaniel Borkmann pr_debug("Invalid size for section %s: %u bytes\n", name, size); 11201713d68bSDaniel Borkmann return -ENOENT; 11211713d68bSDaniel Borkmann } 11221713d68bSDaniel Borkmann 11231713d68bSDaniel Borkmann t->size = size; 11241713d68bSDaniel Borkmann 1125b03bc685SAndrii Nakryiko for (i = 0, vsi = btf_var_secinfos(t); i < vars; i++, vsi++) { 11261713d68bSDaniel Borkmann t_var = btf__type_by_id(btf, vsi->type); 1127b03bc685SAndrii Nakryiko var = btf_var(t_var); 11281713d68bSDaniel Borkmann 1129b03bc685SAndrii Nakryiko if (!btf_is_var(t_var)) { 11301713d68bSDaniel Borkmann pr_debug("Non-VAR type seen in section %s\n", name); 11311713d68bSDaniel Borkmann return -EINVAL; 11321713d68bSDaniel Borkmann } 11331713d68bSDaniel Borkmann 11341713d68bSDaniel Borkmann if (var->linkage == BTF_VAR_STATIC) 11351713d68bSDaniel Borkmann continue; 11361713d68bSDaniel Borkmann 11371713d68bSDaniel Borkmann name = btf__name_by_offset(btf, t_var->name_off); 11381713d68bSDaniel Borkmann if (!name) { 11391713d68bSDaniel Borkmann pr_debug("No name found in string section for VAR kind\n"); 11401713d68bSDaniel Borkmann return -ENOENT; 11411713d68bSDaniel Borkmann } 11421713d68bSDaniel Borkmann 11431713d68bSDaniel Borkmann ret = bpf_object__variable_offset(obj, name, &off); 11441713d68bSDaniel Borkmann if (ret) { 1145b03bc685SAndrii Nakryiko pr_debug("No offset found in symbol table for VAR %s\n", 1146b03bc685SAndrii Nakryiko name); 11471713d68bSDaniel Borkmann return -ENOENT; 11481713d68bSDaniel Borkmann } 11491713d68bSDaniel Borkmann 11501713d68bSDaniel Borkmann vsi->offset = off; 11511713d68bSDaniel Borkmann } 11521713d68bSDaniel Borkmann 1153166750bcSAndrii Nakryiko sort_vars: 1154166750bcSAndrii Nakryiko qsort(btf_var_secinfos(t), vars, sizeof(*vsi), compare_vsi_off); 11551713d68bSDaniel Borkmann return 0; 11561713d68bSDaniel Borkmann } 11571713d68bSDaniel Borkmann 11581713d68bSDaniel Borkmann int btf__finalize_data(struct bpf_object *obj, struct btf *btf) 11591713d68bSDaniel Borkmann { 11601713d68bSDaniel Borkmann int err = 0; 11611713d68bSDaniel Borkmann __u32 i; 11621713d68bSDaniel Borkmann 11631713d68bSDaniel Borkmann for (i = 1; i <= btf->nr_types; i++) { 1164740e69c3SAndrii Nakryiko struct btf_type *t = btf_type_by_id(btf, i); 11651713d68bSDaniel Borkmann 11661713d68bSDaniel Borkmann /* Loader needs to fix up some of the things compiler 11671713d68bSDaniel Borkmann * couldn't get its hands on while emitting BTF. This 11681713d68bSDaniel Borkmann * is section size and global variable offset. We use 11691713d68bSDaniel Borkmann * the info from the ELF itself for this purpose. 11701713d68bSDaniel Borkmann */ 1171b03bc685SAndrii Nakryiko if (btf_is_datasec(t)) { 11721713d68bSDaniel Borkmann err = btf_fixup_datasec(obj, btf, t); 11731713d68bSDaniel Borkmann if (err) 11741713d68bSDaniel Borkmann break; 11751713d68bSDaniel Borkmann } 11761713d68bSDaniel Borkmann } 11771713d68bSDaniel Borkmann 1178e9fc3ce9SAndrii Nakryiko return libbpf_err(err); 11791713d68bSDaniel Borkmann } 11801713d68bSDaniel Borkmann 11813289959bSAndrii Nakryiko static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endian); 11823289959bSAndrii Nakryiko 11833c7e5859SQuentin Monnet int btf__load_into_kernel(struct btf *btf) 1184d29d87f7SAndrii Nakryiko { 1185b8604247SAndrii Nakryiko __u32 log_buf_size = 0, raw_size; 1186d29d87f7SAndrii Nakryiko char *log_buf = NULL; 11873289959bSAndrii Nakryiko void *raw_data; 1188d29d87f7SAndrii Nakryiko int err = 0; 1189d29d87f7SAndrii Nakryiko 1190d29d87f7SAndrii Nakryiko if (btf->fd >= 0) 1191e9fc3ce9SAndrii Nakryiko return libbpf_err(-EEXIST); 1192d29d87f7SAndrii Nakryiko 11938395f320SStanislav Fomichev retry_load: 11948395f320SStanislav Fomichev if (log_buf_size) { 1195d29d87f7SAndrii Nakryiko log_buf = malloc(log_buf_size); 1196d29d87f7SAndrii Nakryiko if (!log_buf) 1197e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 1198d29d87f7SAndrii Nakryiko 1199d29d87f7SAndrii Nakryiko *log_buf = 0; 12008395f320SStanislav Fomichev } 1201d29d87f7SAndrii Nakryiko 12023289959bSAndrii Nakryiko raw_data = btf_get_raw_data(btf, &raw_size, false); 1203b8604247SAndrii Nakryiko if (!raw_data) { 1204b8604247SAndrii Nakryiko err = -ENOMEM; 1205b8604247SAndrii Nakryiko goto done; 1206b8604247SAndrii Nakryiko } 12073289959bSAndrii Nakryiko /* cache native raw data representation */ 12083289959bSAndrii Nakryiko btf->raw_size = raw_size; 12093289959bSAndrii Nakryiko btf->raw_data = raw_data; 1210b8604247SAndrii Nakryiko 1211b8604247SAndrii Nakryiko btf->fd = bpf_load_btf(raw_data, raw_size, log_buf, log_buf_size, false); 1212d29d87f7SAndrii Nakryiko if (btf->fd < 0) { 12138395f320SStanislav Fomichev if (!log_buf || errno == ENOSPC) { 12148395f320SStanislav Fomichev log_buf_size = max((__u32)BPF_LOG_BUF_SIZE, 12158395f320SStanislav Fomichev log_buf_size << 1); 12168395f320SStanislav Fomichev free(log_buf); 12178395f320SStanislav Fomichev goto retry_load; 12188395f320SStanislav Fomichev } 12198395f320SStanislav Fomichev 1220d29d87f7SAndrii Nakryiko err = -errno; 1221be18010eSKefeng Wang pr_warn("Error loading BTF: %s(%d)\n", strerror(errno), errno); 1222d29d87f7SAndrii Nakryiko if (*log_buf) 1223be18010eSKefeng Wang pr_warn("%s\n", log_buf); 1224d29d87f7SAndrii Nakryiko goto done; 1225d29d87f7SAndrii Nakryiko } 1226d29d87f7SAndrii Nakryiko 1227d29d87f7SAndrii Nakryiko done: 1228d29d87f7SAndrii Nakryiko free(log_buf); 1229e9fc3ce9SAndrii Nakryiko return libbpf_err(err); 1230d29d87f7SAndrii Nakryiko } 12313c7e5859SQuentin Monnet int btf__load(struct btf *) __attribute__((alias("btf__load_into_kernel"))); 1232d29d87f7SAndrii Nakryiko 12338a138aedSMartin KaFai Lau int btf__fd(const struct btf *btf) 12348a138aedSMartin KaFai Lau { 12358a138aedSMartin KaFai Lau return btf->fd; 12368a138aedSMartin KaFai Lau } 123792b57121SOkash Khawaja 123881372e12SAndrii Nakryiko void btf__set_fd(struct btf *btf, int fd) 123981372e12SAndrii Nakryiko { 124081372e12SAndrii Nakryiko btf->fd = fd; 124181372e12SAndrii Nakryiko } 124281372e12SAndrii Nakryiko 124390d76d3eSAndrii Nakryiko static const void *btf_strs_data(const struct btf *btf) 124490d76d3eSAndrii Nakryiko { 124590d76d3eSAndrii Nakryiko return btf->strs_data ? btf->strs_data : strset__data(btf->strs_set); 124690d76d3eSAndrii Nakryiko } 124790d76d3eSAndrii Nakryiko 12483289959bSAndrii Nakryiko static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endian) 12493289959bSAndrii Nakryiko { 12503289959bSAndrii Nakryiko struct btf_header *hdr = btf->hdr; 12513289959bSAndrii Nakryiko struct btf_type *t; 12523289959bSAndrii Nakryiko void *data, *p; 12533289959bSAndrii Nakryiko __u32 data_sz; 12543289959bSAndrii Nakryiko int i; 12553289959bSAndrii Nakryiko 12563289959bSAndrii Nakryiko data = swap_endian ? btf->raw_data_swapped : btf->raw_data; 12573289959bSAndrii Nakryiko if (data) { 12583289959bSAndrii Nakryiko *size = btf->raw_size; 12593289959bSAndrii Nakryiko return data; 12603289959bSAndrii Nakryiko } 12613289959bSAndrii Nakryiko 12623289959bSAndrii Nakryiko data_sz = hdr->hdr_len + hdr->type_len + hdr->str_len; 12633289959bSAndrii Nakryiko data = calloc(1, data_sz); 12643289959bSAndrii Nakryiko if (!data) 12653289959bSAndrii Nakryiko return NULL; 12663289959bSAndrii Nakryiko p = data; 12673289959bSAndrii Nakryiko 12683289959bSAndrii Nakryiko memcpy(p, hdr, hdr->hdr_len); 12693289959bSAndrii Nakryiko if (swap_endian) 12703289959bSAndrii Nakryiko btf_bswap_hdr(p); 12713289959bSAndrii Nakryiko p += hdr->hdr_len; 12723289959bSAndrii Nakryiko 12733289959bSAndrii Nakryiko memcpy(p, btf->types_data, hdr->type_len); 12743289959bSAndrii Nakryiko if (swap_endian) { 1275ba451366SAndrii Nakryiko for (i = 0; i < btf->nr_types; i++) { 12763289959bSAndrii Nakryiko t = p + btf->type_offs[i]; 12773289959bSAndrii Nakryiko /* btf_bswap_type_rest() relies on native t->info, so 12783289959bSAndrii Nakryiko * we swap base type info after we swapped all the 12793289959bSAndrii Nakryiko * additional information 12803289959bSAndrii Nakryiko */ 12813289959bSAndrii Nakryiko if (btf_bswap_type_rest(t)) 12823289959bSAndrii Nakryiko goto err_out; 12833289959bSAndrii Nakryiko btf_bswap_type_base(t); 12843289959bSAndrii Nakryiko } 12853289959bSAndrii Nakryiko } 12863289959bSAndrii Nakryiko p += hdr->type_len; 12873289959bSAndrii Nakryiko 128890d76d3eSAndrii Nakryiko memcpy(p, btf_strs_data(btf), hdr->str_len); 12893289959bSAndrii Nakryiko p += hdr->str_len; 12903289959bSAndrii Nakryiko 12913289959bSAndrii Nakryiko *size = data_sz; 12923289959bSAndrii Nakryiko return data; 12933289959bSAndrii Nakryiko err_out: 12943289959bSAndrii Nakryiko free(data); 12953289959bSAndrii Nakryiko return NULL; 12963289959bSAndrii Nakryiko } 12973289959bSAndrii Nakryiko 1298919d2b1dSAndrii Nakryiko const void *btf__get_raw_data(const struct btf *btf_ro, __u32 *size) 129902c87446SAndrii Nakryiko { 1300919d2b1dSAndrii Nakryiko struct btf *btf = (struct btf *)btf_ro; 13013289959bSAndrii Nakryiko __u32 data_sz; 1302919d2b1dSAndrii Nakryiko void *data; 1303919d2b1dSAndrii Nakryiko 13043289959bSAndrii Nakryiko data = btf_get_raw_data(btf, &data_sz, btf->swapped_endian); 13053289959bSAndrii Nakryiko if (!data) 1306e9fc3ce9SAndrii Nakryiko return errno = -ENOMEM, NULL; 1307919d2b1dSAndrii Nakryiko 13083289959bSAndrii Nakryiko btf->raw_size = data_sz; 13093289959bSAndrii Nakryiko if (btf->swapped_endian) 13103289959bSAndrii Nakryiko btf->raw_data_swapped = data; 13113289959bSAndrii Nakryiko else 13123289959bSAndrii Nakryiko btf->raw_data = data; 13133289959bSAndrii Nakryiko *size = data_sz; 13143289959bSAndrii Nakryiko return data; 131502c87446SAndrii Nakryiko } 131602c87446SAndrii Nakryiko 1317f86ed050SAndrii Nakryiko const char *btf__str_by_offset(const struct btf *btf, __u32 offset) 131892b57121SOkash Khawaja { 1319ba451366SAndrii Nakryiko if (offset < btf->start_str_off) 1320ba451366SAndrii Nakryiko return btf__str_by_offset(btf->base_btf, offset); 1321ba451366SAndrii Nakryiko else if (offset - btf->start_str_off < btf->hdr->str_len) 132290d76d3eSAndrii Nakryiko return btf_strs_data(btf) + (offset - btf->start_str_off); 132392b57121SOkash Khawaja else 1324e9fc3ce9SAndrii Nakryiko return errno = EINVAL, NULL; 132592b57121SOkash Khawaja } 13262993e051SYonghong Song 1327f86ed050SAndrii Nakryiko const char *btf__name_by_offset(const struct btf *btf, __u32 offset) 1328f86ed050SAndrii Nakryiko { 1329f86ed050SAndrii Nakryiko return btf__str_by_offset(btf, offset); 1330f86ed050SAndrii Nakryiko } 1331f86ed050SAndrii Nakryiko 1332a19f93cfSAndrii Nakryiko struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf) 1333d7f5b5e0SYonghong Song { 1334a19f93cfSAndrii Nakryiko struct bpf_btf_info btf_info; 1335d7f5b5e0SYonghong Song __u32 len = sizeof(btf_info); 1336d7f5b5e0SYonghong Song __u32 last_size; 1337a19f93cfSAndrii Nakryiko struct btf *btf; 1338d7f5b5e0SYonghong Song void *ptr; 1339d7f5b5e0SYonghong Song int err; 1340d7f5b5e0SYonghong Song 1341d7f5b5e0SYonghong Song /* we won't know btf_size until we call bpf_obj_get_info_by_fd(). so 1342d7f5b5e0SYonghong Song * let's start with a sane default - 4KiB here - and resize it only if 1343d7f5b5e0SYonghong Song * bpf_obj_get_info_by_fd() needs a bigger buffer. 1344d7f5b5e0SYonghong Song */ 1345a19f93cfSAndrii Nakryiko last_size = 4096; 1346d7f5b5e0SYonghong Song ptr = malloc(last_size); 1347a19f93cfSAndrii Nakryiko if (!ptr) 1348a19f93cfSAndrii Nakryiko return ERR_PTR(-ENOMEM); 1349d7f5b5e0SYonghong Song 1350a19f93cfSAndrii Nakryiko memset(&btf_info, 0, sizeof(btf_info)); 1351d7f5b5e0SYonghong Song btf_info.btf = ptr_to_u64(ptr); 1352a19f93cfSAndrii Nakryiko btf_info.btf_size = last_size; 1353d7f5b5e0SYonghong Song err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); 1354d7f5b5e0SYonghong Song 1355d7f5b5e0SYonghong Song if (!err && btf_info.btf_size > last_size) { 1356d7f5b5e0SYonghong Song void *temp_ptr; 1357d7f5b5e0SYonghong Song 1358d7f5b5e0SYonghong Song last_size = btf_info.btf_size; 1359d7f5b5e0SYonghong Song temp_ptr = realloc(ptr, last_size); 1360d7f5b5e0SYonghong Song if (!temp_ptr) { 1361a19f93cfSAndrii Nakryiko btf = ERR_PTR(-ENOMEM); 1362d7f5b5e0SYonghong Song goto exit_free; 1363d7f5b5e0SYonghong Song } 1364d7f5b5e0SYonghong Song ptr = temp_ptr; 1365a19f93cfSAndrii Nakryiko 1366a19f93cfSAndrii Nakryiko len = sizeof(btf_info); 1367a19f93cfSAndrii Nakryiko memset(&btf_info, 0, sizeof(btf_info)); 1368d7f5b5e0SYonghong Song btf_info.btf = ptr_to_u64(ptr); 1369a19f93cfSAndrii Nakryiko btf_info.btf_size = last_size; 1370a19f93cfSAndrii Nakryiko 1371d7f5b5e0SYonghong Song err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); 1372d7f5b5e0SYonghong Song } 1373d7f5b5e0SYonghong Song 1374d7f5b5e0SYonghong Song if (err || btf_info.btf_size > last_size) { 1375a19f93cfSAndrii Nakryiko btf = err ? ERR_PTR(-errno) : ERR_PTR(-E2BIG); 1376d7f5b5e0SYonghong Song goto exit_free; 1377d7f5b5e0SYonghong Song } 1378d7f5b5e0SYonghong Song 1379a19f93cfSAndrii Nakryiko btf = btf_new(ptr, btf_info.btf_size, base_btf); 1380d7f5b5e0SYonghong Song 1381d7f5b5e0SYonghong Song exit_free: 1382d7f5b5e0SYonghong Song free(ptr); 1383a19f93cfSAndrii Nakryiko return btf; 1384a19f93cfSAndrii Nakryiko } 1385d7f5b5e0SYonghong Song 1386*61fc51b1SQuentin Monnet struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf) 13876cc93e2fSQuentin Monnet { 13886cc93e2fSQuentin Monnet struct btf *btf; 13896cc93e2fSQuentin Monnet int btf_fd; 13906cc93e2fSQuentin Monnet 13916cc93e2fSQuentin Monnet btf_fd = bpf_btf_get_fd_by_id(id); 13926cc93e2fSQuentin Monnet if (btf_fd < 0) 13936cc93e2fSQuentin Monnet return libbpf_err_ptr(-errno); 13946cc93e2fSQuentin Monnet 1395*61fc51b1SQuentin Monnet btf = btf_get_from_fd(btf_fd, base_btf); 13966cc93e2fSQuentin Monnet close(btf_fd); 13976cc93e2fSQuentin Monnet 13986cc93e2fSQuentin Monnet return libbpf_ptr(btf); 13996cc93e2fSQuentin Monnet } 14006cc93e2fSQuentin Monnet 1401*61fc51b1SQuentin Monnet struct btf *btf__load_from_kernel_by_id(__u32 id) 1402*61fc51b1SQuentin Monnet { 1403*61fc51b1SQuentin Monnet return btf__load_from_kernel_by_id_split(id, NULL); 1404*61fc51b1SQuentin Monnet } 1405*61fc51b1SQuentin Monnet 1406a19f93cfSAndrii Nakryiko int btf__get_from_id(__u32 id, struct btf **btf) 1407a19f93cfSAndrii Nakryiko { 1408a19f93cfSAndrii Nakryiko struct btf *res; 14096cc93e2fSQuentin Monnet int err; 1410a19f93cfSAndrii Nakryiko 1411a19f93cfSAndrii Nakryiko *btf = NULL; 14126cc93e2fSQuentin Monnet res = btf__load_from_kernel_by_id(id); 1413e9fc3ce9SAndrii Nakryiko err = libbpf_get_error(res); 1414e9fc3ce9SAndrii Nakryiko 1415e9fc3ce9SAndrii Nakryiko if (err) 1416e9fc3ce9SAndrii Nakryiko return libbpf_err(err); 1417a19f93cfSAndrii Nakryiko 1418a19f93cfSAndrii Nakryiko *btf = res; 1419a19f93cfSAndrii Nakryiko return 0; 1420d7f5b5e0SYonghong Song } 1421d7f5b5e0SYonghong Song 1422a6c109a6SYonghong Song int btf__get_map_kv_tids(const struct btf *btf, const char *map_name, 142396408c43SYonghong Song __u32 expected_key_size, __u32 expected_value_size, 142496408c43SYonghong Song __u32 *key_type_id, __u32 *value_type_id) 142596408c43SYonghong Song { 142696408c43SYonghong Song const struct btf_type *container_type; 142796408c43SYonghong Song const struct btf_member *key, *value; 142896408c43SYonghong Song const size_t max_name = 256; 142996408c43SYonghong Song char container_name[max_name]; 143096408c43SYonghong Song __s64 key_size, value_size; 143196408c43SYonghong Song __s32 container_id; 143296408c43SYonghong Song 1433e9fc3ce9SAndrii Nakryiko if (snprintf(container_name, max_name, "____btf_map_%s", map_name) == max_name) { 1434be18010eSKefeng Wang pr_warn("map:%s length of '____btf_map_%s' is too long\n", 143596408c43SYonghong Song map_name, map_name); 1436e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 143796408c43SYonghong Song } 143896408c43SYonghong Song 143996408c43SYonghong Song container_id = btf__find_by_name(btf, container_name); 144096408c43SYonghong Song if (container_id < 0) { 1441f7748e29SYonghong Song pr_debug("map:%s container_name:%s cannot be found in BTF. Missing BPF_ANNOTATE_KV_PAIR?\n", 144296408c43SYonghong Song map_name, container_name); 1443e9fc3ce9SAndrii Nakryiko return libbpf_err(container_id); 144496408c43SYonghong Song } 144596408c43SYonghong Song 144696408c43SYonghong Song container_type = btf__type_by_id(btf, container_id); 144796408c43SYonghong Song if (!container_type) { 1448be18010eSKefeng Wang pr_warn("map:%s cannot find BTF type for container_id:%u\n", 144996408c43SYonghong Song map_name, container_id); 1450e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 145196408c43SYonghong Song } 145296408c43SYonghong Song 1453b03bc685SAndrii Nakryiko if (!btf_is_struct(container_type) || btf_vlen(container_type) < 2) { 1454be18010eSKefeng Wang pr_warn("map:%s container_name:%s is an invalid container struct\n", 145596408c43SYonghong Song map_name, container_name); 1456e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 145796408c43SYonghong Song } 145896408c43SYonghong Song 1459b03bc685SAndrii Nakryiko key = btf_members(container_type); 146096408c43SYonghong Song value = key + 1; 146196408c43SYonghong Song 146296408c43SYonghong Song key_size = btf__resolve_size(btf, key->type); 146396408c43SYonghong Song if (key_size < 0) { 1464be18010eSKefeng Wang pr_warn("map:%s invalid BTF key_type_size\n", map_name); 1465e9fc3ce9SAndrii Nakryiko return libbpf_err(key_size); 146696408c43SYonghong Song } 146796408c43SYonghong Song 146896408c43SYonghong Song if (expected_key_size != key_size) { 1469be18010eSKefeng Wang pr_warn("map:%s btf_key_type_size:%u != map_def_key_size:%u\n", 147096408c43SYonghong Song map_name, (__u32)key_size, expected_key_size); 1471e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 147296408c43SYonghong Song } 147396408c43SYonghong Song 147496408c43SYonghong Song value_size = btf__resolve_size(btf, value->type); 147596408c43SYonghong Song if (value_size < 0) { 1476be18010eSKefeng Wang pr_warn("map:%s invalid BTF value_type_size\n", map_name); 1477e9fc3ce9SAndrii Nakryiko return libbpf_err(value_size); 147896408c43SYonghong Song } 147996408c43SYonghong Song 148096408c43SYonghong Song if (expected_value_size != value_size) { 1481be18010eSKefeng Wang pr_warn("map:%s btf_value_type_size:%u != map_def_value_size:%u\n", 148296408c43SYonghong Song map_name, (__u32)value_size, expected_value_size); 1483e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 148496408c43SYonghong Song } 148596408c43SYonghong Song 148696408c43SYonghong Song *key_type_id = key->type; 148796408c43SYonghong Song *value_type_id = value->type; 148896408c43SYonghong Song 148996408c43SYonghong Song return 0; 149096408c43SYonghong Song } 149196408c43SYonghong Song 14923289959bSAndrii Nakryiko static void btf_invalidate_raw_data(struct btf *btf) 14933289959bSAndrii Nakryiko { 14943289959bSAndrii Nakryiko if (btf->raw_data) { 14953289959bSAndrii Nakryiko free(btf->raw_data); 14963289959bSAndrii Nakryiko btf->raw_data = NULL; 14973289959bSAndrii Nakryiko } 14983289959bSAndrii Nakryiko if (btf->raw_data_swapped) { 14993289959bSAndrii Nakryiko free(btf->raw_data_swapped); 15003289959bSAndrii Nakryiko btf->raw_data_swapped = NULL; 15013289959bSAndrii Nakryiko } 15023289959bSAndrii Nakryiko } 15033289959bSAndrii Nakryiko 1504919d2b1dSAndrii Nakryiko /* Ensure BTF is ready to be modified (by splitting into a three memory 1505919d2b1dSAndrii Nakryiko * regions for header, types, and strings). Also invalidate cached 1506919d2b1dSAndrii Nakryiko * raw_data, if any. 1507919d2b1dSAndrii Nakryiko */ 1508919d2b1dSAndrii Nakryiko static int btf_ensure_modifiable(struct btf *btf) 1509919d2b1dSAndrii Nakryiko { 151090d76d3eSAndrii Nakryiko void *hdr, *types; 151190d76d3eSAndrii Nakryiko struct strset *set = NULL; 151290d76d3eSAndrii Nakryiko int err = -ENOMEM; 1513919d2b1dSAndrii Nakryiko 1514919d2b1dSAndrii Nakryiko if (btf_is_modifiable(btf)) { 1515919d2b1dSAndrii Nakryiko /* any BTF modification invalidates raw_data */ 15163289959bSAndrii Nakryiko btf_invalidate_raw_data(btf); 1517919d2b1dSAndrii Nakryiko return 0; 1518919d2b1dSAndrii Nakryiko } 1519919d2b1dSAndrii Nakryiko 1520919d2b1dSAndrii Nakryiko /* split raw data into three memory regions */ 1521919d2b1dSAndrii Nakryiko hdr = malloc(btf->hdr->hdr_len); 1522919d2b1dSAndrii Nakryiko types = malloc(btf->hdr->type_len); 152390d76d3eSAndrii Nakryiko if (!hdr || !types) 1524919d2b1dSAndrii Nakryiko goto err_out; 1525919d2b1dSAndrii Nakryiko 1526919d2b1dSAndrii Nakryiko memcpy(hdr, btf->hdr, btf->hdr->hdr_len); 1527919d2b1dSAndrii Nakryiko memcpy(types, btf->types_data, btf->hdr->type_len); 152888a82c2aSAndrii Nakryiko 1529919d2b1dSAndrii Nakryiko /* build lookup index for all strings */ 153090d76d3eSAndrii Nakryiko set = strset__new(BTF_MAX_STR_OFFSET, btf->strs_data, btf->hdr->str_len); 153190d76d3eSAndrii Nakryiko if (IS_ERR(set)) { 153290d76d3eSAndrii Nakryiko err = PTR_ERR(set); 1533919d2b1dSAndrii Nakryiko goto err_out; 1534919d2b1dSAndrii Nakryiko } 1535919d2b1dSAndrii Nakryiko 1536919d2b1dSAndrii Nakryiko /* only when everything was successful, update internal state */ 1537919d2b1dSAndrii Nakryiko btf->hdr = hdr; 1538919d2b1dSAndrii Nakryiko btf->types_data = types; 1539919d2b1dSAndrii Nakryiko btf->types_data_cap = btf->hdr->type_len; 154090d76d3eSAndrii Nakryiko btf->strs_data = NULL; 154190d76d3eSAndrii Nakryiko btf->strs_set = set; 1542919d2b1dSAndrii Nakryiko /* if BTF was created from scratch, all strings are guaranteed to be 1543919d2b1dSAndrii Nakryiko * unique and deduplicated 1544919d2b1dSAndrii Nakryiko */ 1545ba451366SAndrii Nakryiko if (btf->hdr->str_len == 0) 1546ba451366SAndrii Nakryiko btf->strs_deduped = true; 1547ba451366SAndrii Nakryiko if (!btf->base_btf && btf->hdr->str_len == 1) 1548ba451366SAndrii Nakryiko btf->strs_deduped = true; 1549919d2b1dSAndrii Nakryiko 1550919d2b1dSAndrii Nakryiko /* invalidate raw_data representation */ 15513289959bSAndrii Nakryiko btf_invalidate_raw_data(btf); 1552919d2b1dSAndrii Nakryiko 1553919d2b1dSAndrii Nakryiko return 0; 1554919d2b1dSAndrii Nakryiko 1555919d2b1dSAndrii Nakryiko err_out: 155690d76d3eSAndrii Nakryiko strset__free(set); 1557919d2b1dSAndrii Nakryiko free(hdr); 1558919d2b1dSAndrii Nakryiko free(types); 155990d76d3eSAndrii Nakryiko return err; 1560919d2b1dSAndrii Nakryiko } 1561919d2b1dSAndrii Nakryiko 1562919d2b1dSAndrii Nakryiko /* Find an offset in BTF string section that corresponds to a given string *s*. 1563919d2b1dSAndrii Nakryiko * Returns: 1564919d2b1dSAndrii Nakryiko * - >0 offset into string section, if string is found; 1565919d2b1dSAndrii Nakryiko * - -ENOENT, if string is not in the string section; 1566919d2b1dSAndrii Nakryiko * - <0, on any other error. 1567919d2b1dSAndrii Nakryiko */ 1568919d2b1dSAndrii Nakryiko int btf__find_str(struct btf *btf, const char *s) 1569919d2b1dSAndrii Nakryiko { 157090d76d3eSAndrii Nakryiko int off; 1571919d2b1dSAndrii Nakryiko 1572ba451366SAndrii Nakryiko if (btf->base_btf) { 157390d76d3eSAndrii Nakryiko off = btf__find_str(btf->base_btf, s); 157490d76d3eSAndrii Nakryiko if (off != -ENOENT) 157590d76d3eSAndrii Nakryiko return off; 1576ba451366SAndrii Nakryiko } 1577ba451366SAndrii Nakryiko 1578919d2b1dSAndrii Nakryiko /* BTF needs to be in a modifiable state to build string lookup index */ 1579919d2b1dSAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1580e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 1581919d2b1dSAndrii Nakryiko 158290d76d3eSAndrii Nakryiko off = strset__find_str(btf->strs_set, s); 158390d76d3eSAndrii Nakryiko if (off < 0) 1584e9fc3ce9SAndrii Nakryiko return libbpf_err(off); 1585919d2b1dSAndrii Nakryiko 158690d76d3eSAndrii Nakryiko return btf->start_str_off + off; 1587919d2b1dSAndrii Nakryiko } 1588919d2b1dSAndrii Nakryiko 1589919d2b1dSAndrii Nakryiko /* Add a string s to the BTF string section. 1590919d2b1dSAndrii Nakryiko * Returns: 1591919d2b1dSAndrii Nakryiko * - > 0 offset into string section, on success; 1592919d2b1dSAndrii Nakryiko * - < 0, on error. 1593919d2b1dSAndrii Nakryiko */ 1594919d2b1dSAndrii Nakryiko int btf__add_str(struct btf *btf, const char *s) 1595919d2b1dSAndrii Nakryiko { 159690d76d3eSAndrii Nakryiko int off; 1597919d2b1dSAndrii Nakryiko 1598ba451366SAndrii Nakryiko if (btf->base_btf) { 159990d76d3eSAndrii Nakryiko off = btf__find_str(btf->base_btf, s); 160090d76d3eSAndrii Nakryiko if (off != -ENOENT) 160190d76d3eSAndrii Nakryiko return off; 1602ba451366SAndrii Nakryiko } 1603ba451366SAndrii Nakryiko 1604919d2b1dSAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1605e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 1606919d2b1dSAndrii Nakryiko 160790d76d3eSAndrii Nakryiko off = strset__add_str(btf->strs_set, s); 160890d76d3eSAndrii Nakryiko if (off < 0) 1609e9fc3ce9SAndrii Nakryiko return libbpf_err(off); 1610919d2b1dSAndrii Nakryiko 161190d76d3eSAndrii Nakryiko btf->hdr->str_len = strset__data_size(btf->strs_set); 1612919d2b1dSAndrii Nakryiko 161390d76d3eSAndrii Nakryiko return btf->start_str_off + off; 1614919d2b1dSAndrii Nakryiko } 1615919d2b1dSAndrii Nakryiko 16164a3b33f8SAndrii Nakryiko static void *btf_add_type_mem(struct btf *btf, size_t add_sz) 16174a3b33f8SAndrii Nakryiko { 16183b029e06SAndrii Nakryiko return libbpf_add_mem(&btf->types_data, &btf->types_data_cap, 1, 16194a3b33f8SAndrii Nakryiko btf->hdr->type_len, UINT_MAX, add_sz); 16204a3b33f8SAndrii Nakryiko } 16214a3b33f8SAndrii Nakryiko 16224a3b33f8SAndrii Nakryiko static void btf_type_inc_vlen(struct btf_type *t) 16234a3b33f8SAndrii Nakryiko { 16244a3b33f8SAndrii Nakryiko t->info = btf_type_info(btf_kind(t), btf_vlen(t) + 1, btf_kflag(t)); 16254a3b33f8SAndrii Nakryiko } 16264a3b33f8SAndrii Nakryiko 1627c81ed6d8SAndrii Nakryiko static int btf_commit_type(struct btf *btf, int data_sz) 1628c81ed6d8SAndrii Nakryiko { 1629c81ed6d8SAndrii Nakryiko int err; 1630c81ed6d8SAndrii Nakryiko 1631c81ed6d8SAndrii Nakryiko err = btf_add_type_idx_entry(btf, btf->hdr->type_len); 1632c81ed6d8SAndrii Nakryiko if (err) 1633e9fc3ce9SAndrii Nakryiko return libbpf_err(err); 1634c81ed6d8SAndrii Nakryiko 1635c81ed6d8SAndrii Nakryiko btf->hdr->type_len += data_sz; 1636c81ed6d8SAndrii Nakryiko btf->hdr->str_off += data_sz; 1637c81ed6d8SAndrii Nakryiko btf->nr_types++; 1638ba451366SAndrii Nakryiko return btf->start_id + btf->nr_types - 1; 1639c81ed6d8SAndrii Nakryiko } 1640c81ed6d8SAndrii Nakryiko 16419af44bc5SAndrii Nakryiko struct btf_pipe { 16429af44bc5SAndrii Nakryiko const struct btf *src; 16439af44bc5SAndrii Nakryiko struct btf *dst; 16449af44bc5SAndrii Nakryiko }; 16459af44bc5SAndrii Nakryiko 16469af44bc5SAndrii Nakryiko static int btf_rewrite_str(__u32 *str_off, void *ctx) 16479af44bc5SAndrii Nakryiko { 16489af44bc5SAndrii Nakryiko struct btf_pipe *p = ctx; 16499af44bc5SAndrii Nakryiko int off; 16509af44bc5SAndrii Nakryiko 16519af44bc5SAndrii Nakryiko if (!*str_off) /* nothing to do for empty strings */ 16529af44bc5SAndrii Nakryiko return 0; 16539af44bc5SAndrii Nakryiko 16549af44bc5SAndrii Nakryiko off = btf__add_str(p->dst, btf__str_by_offset(p->src, *str_off)); 16559af44bc5SAndrii Nakryiko if (off < 0) 16569af44bc5SAndrii Nakryiko return off; 16579af44bc5SAndrii Nakryiko 16589af44bc5SAndrii Nakryiko *str_off = off; 16599af44bc5SAndrii Nakryiko return 0; 16609af44bc5SAndrii Nakryiko } 16619af44bc5SAndrii Nakryiko 16629af44bc5SAndrii Nakryiko int btf__add_type(struct btf *btf, const struct btf *src_btf, const struct btf_type *src_type) 16639af44bc5SAndrii Nakryiko { 16649af44bc5SAndrii Nakryiko struct btf_pipe p = { .src = src_btf, .dst = btf }; 16659af44bc5SAndrii Nakryiko struct btf_type *t; 16669af44bc5SAndrii Nakryiko int sz, err; 16679af44bc5SAndrii Nakryiko 16689af44bc5SAndrii Nakryiko sz = btf_type_size(src_type); 16699af44bc5SAndrii Nakryiko if (sz < 0) 1670e9fc3ce9SAndrii Nakryiko return libbpf_err(sz); 16719af44bc5SAndrii Nakryiko 16729af44bc5SAndrii Nakryiko /* deconstruct BTF, if necessary, and invalidate raw_data */ 16739af44bc5SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1674e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 16759af44bc5SAndrii Nakryiko 16769af44bc5SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 16779af44bc5SAndrii Nakryiko if (!t) 1678e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 16799af44bc5SAndrii Nakryiko 16809af44bc5SAndrii Nakryiko memcpy(t, src_type, sz); 16819af44bc5SAndrii Nakryiko 16829af44bc5SAndrii Nakryiko err = btf_type_visit_str_offs(t, btf_rewrite_str, &p); 16839af44bc5SAndrii Nakryiko if (err) 1684e9fc3ce9SAndrii Nakryiko return libbpf_err(err); 16859af44bc5SAndrii Nakryiko 16869af44bc5SAndrii Nakryiko return btf_commit_type(btf, sz); 16879af44bc5SAndrii Nakryiko } 16889af44bc5SAndrii Nakryiko 16894a3b33f8SAndrii Nakryiko /* 16904a3b33f8SAndrii Nakryiko * Append new BTF_KIND_INT type with: 16914a3b33f8SAndrii Nakryiko * - *name* - non-empty, non-NULL type name; 16924a3b33f8SAndrii Nakryiko * - *sz* - power-of-2 (1, 2, 4, ..) size of the type, in bytes; 16934a3b33f8SAndrii Nakryiko * - encoding is a combination of BTF_INT_SIGNED, BTF_INT_CHAR, BTF_INT_BOOL. 16944a3b33f8SAndrii Nakryiko * Returns: 16954a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 16964a3b33f8SAndrii Nakryiko * - <0, on error. 16974a3b33f8SAndrii Nakryiko */ 16984a3b33f8SAndrii Nakryiko int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding) 16994a3b33f8SAndrii Nakryiko { 17004a3b33f8SAndrii Nakryiko struct btf_type *t; 1701c81ed6d8SAndrii Nakryiko int sz, name_off; 17024a3b33f8SAndrii Nakryiko 17034a3b33f8SAndrii Nakryiko /* non-empty name */ 17044a3b33f8SAndrii Nakryiko if (!name || !name[0]) 1705e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 17064a3b33f8SAndrii Nakryiko /* byte_sz must be power of 2 */ 17074a3b33f8SAndrii Nakryiko if (!byte_sz || (byte_sz & (byte_sz - 1)) || byte_sz > 16) 1708e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 17094a3b33f8SAndrii Nakryiko if (encoding & ~(BTF_INT_SIGNED | BTF_INT_CHAR | BTF_INT_BOOL)) 1710e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 17114a3b33f8SAndrii Nakryiko 17124a3b33f8SAndrii Nakryiko /* deconstruct BTF, if necessary, and invalidate raw_data */ 17134a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1714e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 17154a3b33f8SAndrii Nakryiko 17164a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type) + sizeof(int); 17174a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 17184a3b33f8SAndrii Nakryiko if (!t) 1719e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 17204a3b33f8SAndrii Nakryiko 17214a3b33f8SAndrii Nakryiko /* if something goes wrong later, we might end up with an extra string, 17224a3b33f8SAndrii Nakryiko * but that shouldn't be a problem, because BTF can't be constructed 17234a3b33f8SAndrii Nakryiko * completely anyway and will most probably be just discarded 17244a3b33f8SAndrii Nakryiko */ 17254a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 17264a3b33f8SAndrii Nakryiko if (name_off < 0) 17274a3b33f8SAndrii Nakryiko return name_off; 17284a3b33f8SAndrii Nakryiko 17294a3b33f8SAndrii Nakryiko t->name_off = name_off; 17304a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_INT, 0, 0); 17314a3b33f8SAndrii Nakryiko t->size = byte_sz; 17324a3b33f8SAndrii Nakryiko /* set INT info, we don't allow setting legacy bit offset/size */ 17334a3b33f8SAndrii Nakryiko *(__u32 *)(t + 1) = (encoding << 24) | (byte_sz * 8); 17344a3b33f8SAndrii Nakryiko 1735c81ed6d8SAndrii Nakryiko return btf_commit_type(btf, sz); 17364a3b33f8SAndrii Nakryiko } 17374a3b33f8SAndrii Nakryiko 173822541a9eSIlya Leoshkevich /* 173922541a9eSIlya Leoshkevich * Append new BTF_KIND_FLOAT type with: 174022541a9eSIlya Leoshkevich * - *name* - non-empty, non-NULL type name; 174122541a9eSIlya Leoshkevich * - *sz* - size of the type, in bytes; 174222541a9eSIlya Leoshkevich * Returns: 174322541a9eSIlya Leoshkevich * - >0, type ID of newly added BTF type; 174422541a9eSIlya Leoshkevich * - <0, on error. 174522541a9eSIlya Leoshkevich */ 174622541a9eSIlya Leoshkevich int btf__add_float(struct btf *btf, const char *name, size_t byte_sz) 174722541a9eSIlya Leoshkevich { 174822541a9eSIlya Leoshkevich struct btf_type *t; 174922541a9eSIlya Leoshkevich int sz, name_off; 175022541a9eSIlya Leoshkevich 175122541a9eSIlya Leoshkevich /* non-empty name */ 175222541a9eSIlya Leoshkevich if (!name || !name[0]) 1753e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 175422541a9eSIlya Leoshkevich 175522541a9eSIlya Leoshkevich /* byte_sz must be one of the explicitly allowed values */ 175622541a9eSIlya Leoshkevich if (byte_sz != 2 && byte_sz != 4 && byte_sz != 8 && byte_sz != 12 && 175722541a9eSIlya Leoshkevich byte_sz != 16) 1758e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 175922541a9eSIlya Leoshkevich 176022541a9eSIlya Leoshkevich if (btf_ensure_modifiable(btf)) 1761e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 176222541a9eSIlya Leoshkevich 176322541a9eSIlya Leoshkevich sz = sizeof(struct btf_type); 176422541a9eSIlya Leoshkevich t = btf_add_type_mem(btf, sz); 176522541a9eSIlya Leoshkevich if (!t) 1766e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 176722541a9eSIlya Leoshkevich 176822541a9eSIlya Leoshkevich name_off = btf__add_str(btf, name); 176922541a9eSIlya Leoshkevich if (name_off < 0) 177022541a9eSIlya Leoshkevich return name_off; 177122541a9eSIlya Leoshkevich 177222541a9eSIlya Leoshkevich t->name_off = name_off; 177322541a9eSIlya Leoshkevich t->info = btf_type_info(BTF_KIND_FLOAT, 0, 0); 177422541a9eSIlya Leoshkevich t->size = byte_sz; 177522541a9eSIlya Leoshkevich 177622541a9eSIlya Leoshkevich return btf_commit_type(btf, sz); 177722541a9eSIlya Leoshkevich } 177822541a9eSIlya Leoshkevich 17794a3b33f8SAndrii Nakryiko /* it's completely legal to append BTF types with type IDs pointing forward to 17804a3b33f8SAndrii Nakryiko * types that haven't been appended yet, so we only make sure that id looks 17814a3b33f8SAndrii Nakryiko * sane, we can't guarantee that ID will always be valid 17824a3b33f8SAndrii Nakryiko */ 17834a3b33f8SAndrii Nakryiko static int validate_type_id(int id) 17844a3b33f8SAndrii Nakryiko { 17854a3b33f8SAndrii Nakryiko if (id < 0 || id > BTF_MAX_NR_TYPES) 17864a3b33f8SAndrii Nakryiko return -EINVAL; 17874a3b33f8SAndrii Nakryiko return 0; 17884a3b33f8SAndrii Nakryiko } 17894a3b33f8SAndrii Nakryiko 17904a3b33f8SAndrii Nakryiko /* generic append function for PTR, TYPEDEF, CONST/VOLATILE/RESTRICT */ 17914a3b33f8SAndrii Nakryiko static int btf_add_ref_kind(struct btf *btf, int kind, const char *name, int ref_type_id) 17924a3b33f8SAndrii Nakryiko { 17934a3b33f8SAndrii Nakryiko struct btf_type *t; 1794c81ed6d8SAndrii Nakryiko int sz, name_off = 0; 17954a3b33f8SAndrii Nakryiko 17964a3b33f8SAndrii Nakryiko if (validate_type_id(ref_type_id)) 1797e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 17984a3b33f8SAndrii Nakryiko 17994a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1800e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 18014a3b33f8SAndrii Nakryiko 18024a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type); 18034a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 18044a3b33f8SAndrii Nakryiko if (!t) 1805e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 18064a3b33f8SAndrii Nakryiko 18074a3b33f8SAndrii Nakryiko if (name && name[0]) { 18084a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 18094a3b33f8SAndrii Nakryiko if (name_off < 0) 18104a3b33f8SAndrii Nakryiko return name_off; 18114a3b33f8SAndrii Nakryiko } 18124a3b33f8SAndrii Nakryiko 18134a3b33f8SAndrii Nakryiko t->name_off = name_off; 18144a3b33f8SAndrii Nakryiko t->info = btf_type_info(kind, 0, 0); 18154a3b33f8SAndrii Nakryiko t->type = ref_type_id; 18164a3b33f8SAndrii Nakryiko 1817c81ed6d8SAndrii Nakryiko return btf_commit_type(btf, sz); 18184a3b33f8SAndrii Nakryiko } 18194a3b33f8SAndrii Nakryiko 18204a3b33f8SAndrii Nakryiko /* 18214a3b33f8SAndrii Nakryiko * Append new BTF_KIND_PTR type with: 18224a3b33f8SAndrii Nakryiko * - *ref_type_id* - referenced type ID, it might not exist yet; 18234a3b33f8SAndrii Nakryiko * Returns: 18244a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 18254a3b33f8SAndrii Nakryiko * - <0, on error. 18264a3b33f8SAndrii Nakryiko */ 18274a3b33f8SAndrii Nakryiko int btf__add_ptr(struct btf *btf, int ref_type_id) 18284a3b33f8SAndrii Nakryiko { 18294a3b33f8SAndrii Nakryiko return btf_add_ref_kind(btf, BTF_KIND_PTR, NULL, ref_type_id); 18304a3b33f8SAndrii Nakryiko } 18314a3b33f8SAndrii Nakryiko 18324a3b33f8SAndrii Nakryiko /* 18334a3b33f8SAndrii Nakryiko * Append new BTF_KIND_ARRAY type with: 18344a3b33f8SAndrii Nakryiko * - *index_type_id* - type ID of the type describing array index; 18354a3b33f8SAndrii Nakryiko * - *elem_type_id* - type ID of the type describing array element; 18364a3b33f8SAndrii Nakryiko * - *nr_elems* - the size of the array; 18374a3b33f8SAndrii Nakryiko * Returns: 18384a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 18394a3b33f8SAndrii Nakryiko * - <0, on error. 18404a3b33f8SAndrii Nakryiko */ 18414a3b33f8SAndrii Nakryiko int btf__add_array(struct btf *btf, int index_type_id, int elem_type_id, __u32 nr_elems) 18424a3b33f8SAndrii Nakryiko { 18434a3b33f8SAndrii Nakryiko struct btf_type *t; 18444a3b33f8SAndrii Nakryiko struct btf_array *a; 1845c81ed6d8SAndrii Nakryiko int sz; 18464a3b33f8SAndrii Nakryiko 18474a3b33f8SAndrii Nakryiko if (validate_type_id(index_type_id) || validate_type_id(elem_type_id)) 1848e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 18494a3b33f8SAndrii Nakryiko 18504a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1851e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 18524a3b33f8SAndrii Nakryiko 18534a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type) + sizeof(struct btf_array); 18544a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 18554a3b33f8SAndrii Nakryiko if (!t) 1856e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 18574a3b33f8SAndrii Nakryiko 18584a3b33f8SAndrii Nakryiko t->name_off = 0; 18594a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_ARRAY, 0, 0); 18604a3b33f8SAndrii Nakryiko t->size = 0; 18614a3b33f8SAndrii Nakryiko 18624a3b33f8SAndrii Nakryiko a = btf_array(t); 18634a3b33f8SAndrii Nakryiko a->type = elem_type_id; 18644a3b33f8SAndrii Nakryiko a->index_type = index_type_id; 18654a3b33f8SAndrii Nakryiko a->nelems = nr_elems; 18664a3b33f8SAndrii Nakryiko 1867c81ed6d8SAndrii Nakryiko return btf_commit_type(btf, sz); 18684a3b33f8SAndrii Nakryiko } 18694a3b33f8SAndrii Nakryiko 18704a3b33f8SAndrii Nakryiko /* generic STRUCT/UNION append function */ 18714a3b33f8SAndrii Nakryiko static int btf_add_composite(struct btf *btf, int kind, const char *name, __u32 bytes_sz) 18724a3b33f8SAndrii Nakryiko { 18734a3b33f8SAndrii Nakryiko struct btf_type *t; 1874c81ed6d8SAndrii Nakryiko int sz, name_off = 0; 18754a3b33f8SAndrii Nakryiko 18764a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1877e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 18784a3b33f8SAndrii Nakryiko 18794a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type); 18804a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 18814a3b33f8SAndrii Nakryiko if (!t) 1882e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 18834a3b33f8SAndrii Nakryiko 18844a3b33f8SAndrii Nakryiko if (name && name[0]) { 18854a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 18864a3b33f8SAndrii Nakryiko if (name_off < 0) 18874a3b33f8SAndrii Nakryiko return name_off; 18884a3b33f8SAndrii Nakryiko } 18894a3b33f8SAndrii Nakryiko 18904a3b33f8SAndrii Nakryiko /* start out with vlen=0 and no kflag; this will be adjusted when 18914a3b33f8SAndrii Nakryiko * adding each member 18924a3b33f8SAndrii Nakryiko */ 18934a3b33f8SAndrii Nakryiko t->name_off = name_off; 18944a3b33f8SAndrii Nakryiko t->info = btf_type_info(kind, 0, 0); 18954a3b33f8SAndrii Nakryiko t->size = bytes_sz; 18964a3b33f8SAndrii Nakryiko 1897c81ed6d8SAndrii Nakryiko return btf_commit_type(btf, sz); 18984a3b33f8SAndrii Nakryiko } 18994a3b33f8SAndrii Nakryiko 19004a3b33f8SAndrii Nakryiko /* 19014a3b33f8SAndrii Nakryiko * Append new BTF_KIND_STRUCT type with: 19024a3b33f8SAndrii Nakryiko * - *name* - name of the struct, can be NULL or empty for anonymous structs; 19034a3b33f8SAndrii Nakryiko * - *byte_sz* - size of the struct, in bytes; 19044a3b33f8SAndrii Nakryiko * 19054a3b33f8SAndrii Nakryiko * Struct initially has no fields in it. Fields can be added by 19064a3b33f8SAndrii Nakryiko * btf__add_field() right after btf__add_struct() succeeds. 19074a3b33f8SAndrii Nakryiko * 19084a3b33f8SAndrii Nakryiko * Returns: 19094a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 19104a3b33f8SAndrii Nakryiko * - <0, on error. 19114a3b33f8SAndrii Nakryiko */ 19124a3b33f8SAndrii Nakryiko int btf__add_struct(struct btf *btf, const char *name, __u32 byte_sz) 19134a3b33f8SAndrii Nakryiko { 19144a3b33f8SAndrii Nakryiko return btf_add_composite(btf, BTF_KIND_STRUCT, name, byte_sz); 19154a3b33f8SAndrii Nakryiko } 19164a3b33f8SAndrii Nakryiko 19174a3b33f8SAndrii Nakryiko /* 19184a3b33f8SAndrii Nakryiko * Append new BTF_KIND_UNION type with: 19194a3b33f8SAndrii Nakryiko * - *name* - name of the union, can be NULL or empty for anonymous union; 19204a3b33f8SAndrii Nakryiko * - *byte_sz* - size of the union, in bytes; 19214a3b33f8SAndrii Nakryiko * 19224a3b33f8SAndrii Nakryiko * Union initially has no fields in it. Fields can be added by 19234a3b33f8SAndrii Nakryiko * btf__add_field() right after btf__add_union() succeeds. All fields 19244a3b33f8SAndrii Nakryiko * should have *bit_offset* of 0. 19254a3b33f8SAndrii Nakryiko * 19264a3b33f8SAndrii Nakryiko * Returns: 19274a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 19284a3b33f8SAndrii Nakryiko * - <0, on error. 19294a3b33f8SAndrii Nakryiko */ 19304a3b33f8SAndrii Nakryiko int btf__add_union(struct btf *btf, const char *name, __u32 byte_sz) 19314a3b33f8SAndrii Nakryiko { 19324a3b33f8SAndrii Nakryiko return btf_add_composite(btf, BTF_KIND_UNION, name, byte_sz); 19334a3b33f8SAndrii Nakryiko } 19344a3b33f8SAndrii Nakryiko 1935c81ed6d8SAndrii Nakryiko static struct btf_type *btf_last_type(struct btf *btf) 1936c81ed6d8SAndrii Nakryiko { 1937c81ed6d8SAndrii Nakryiko return btf_type_by_id(btf, btf__get_nr_types(btf)); 1938c81ed6d8SAndrii Nakryiko } 1939c81ed6d8SAndrii Nakryiko 19404a3b33f8SAndrii Nakryiko /* 19414a3b33f8SAndrii Nakryiko * Append new field for the current STRUCT/UNION type with: 19424a3b33f8SAndrii Nakryiko * - *name* - name of the field, can be NULL or empty for anonymous field; 19434a3b33f8SAndrii Nakryiko * - *type_id* - type ID for the type describing field type; 19444a3b33f8SAndrii Nakryiko * - *bit_offset* - bit offset of the start of the field within struct/union; 19454a3b33f8SAndrii Nakryiko * - *bit_size* - bit size of a bitfield, 0 for non-bitfield fields; 19464a3b33f8SAndrii Nakryiko * Returns: 19474a3b33f8SAndrii Nakryiko * - 0, on success; 19484a3b33f8SAndrii Nakryiko * - <0, on error. 19494a3b33f8SAndrii Nakryiko */ 19504a3b33f8SAndrii Nakryiko int btf__add_field(struct btf *btf, const char *name, int type_id, 19514a3b33f8SAndrii Nakryiko __u32 bit_offset, __u32 bit_size) 19524a3b33f8SAndrii Nakryiko { 19534a3b33f8SAndrii Nakryiko struct btf_type *t; 19544a3b33f8SAndrii Nakryiko struct btf_member *m; 19554a3b33f8SAndrii Nakryiko bool is_bitfield; 19564a3b33f8SAndrii Nakryiko int sz, name_off = 0; 19574a3b33f8SAndrii Nakryiko 19584a3b33f8SAndrii Nakryiko /* last type should be union/struct */ 19594a3b33f8SAndrii Nakryiko if (btf->nr_types == 0) 1960e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 1961c81ed6d8SAndrii Nakryiko t = btf_last_type(btf); 19624a3b33f8SAndrii Nakryiko if (!btf_is_composite(t)) 1963e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 19644a3b33f8SAndrii Nakryiko 19654a3b33f8SAndrii Nakryiko if (validate_type_id(type_id)) 1966e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 19674a3b33f8SAndrii Nakryiko /* best-effort bit field offset/size enforcement */ 19684a3b33f8SAndrii Nakryiko is_bitfield = bit_size || (bit_offset % 8 != 0); 19694a3b33f8SAndrii Nakryiko if (is_bitfield && (bit_size == 0 || bit_size > 255 || bit_offset > 0xffffff)) 1970e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 19714a3b33f8SAndrii Nakryiko 19724a3b33f8SAndrii Nakryiko /* only offset 0 is allowed for unions */ 19734a3b33f8SAndrii Nakryiko if (btf_is_union(t) && bit_offset) 1974e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 19754a3b33f8SAndrii Nakryiko 19764a3b33f8SAndrii Nakryiko /* decompose and invalidate raw data */ 19774a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1978e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 19794a3b33f8SAndrii Nakryiko 19804a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_member); 19814a3b33f8SAndrii Nakryiko m = btf_add_type_mem(btf, sz); 19824a3b33f8SAndrii Nakryiko if (!m) 1983e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 19844a3b33f8SAndrii Nakryiko 19854a3b33f8SAndrii Nakryiko if (name && name[0]) { 19864a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 19874a3b33f8SAndrii Nakryiko if (name_off < 0) 19884a3b33f8SAndrii Nakryiko return name_off; 19894a3b33f8SAndrii Nakryiko } 19904a3b33f8SAndrii Nakryiko 19914a3b33f8SAndrii Nakryiko m->name_off = name_off; 19924a3b33f8SAndrii Nakryiko m->type = type_id; 19934a3b33f8SAndrii Nakryiko m->offset = bit_offset | (bit_size << 24); 19944a3b33f8SAndrii Nakryiko 19954a3b33f8SAndrii Nakryiko /* btf_add_type_mem can invalidate t pointer */ 1996c81ed6d8SAndrii Nakryiko t = btf_last_type(btf); 19974a3b33f8SAndrii Nakryiko /* update parent type's vlen and kflag */ 19984a3b33f8SAndrii Nakryiko t->info = btf_type_info(btf_kind(t), btf_vlen(t) + 1, is_bitfield || btf_kflag(t)); 19994a3b33f8SAndrii Nakryiko 20004a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 20014a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 20024a3b33f8SAndrii Nakryiko return 0; 20034a3b33f8SAndrii Nakryiko } 20044a3b33f8SAndrii Nakryiko 20054a3b33f8SAndrii Nakryiko /* 20064a3b33f8SAndrii Nakryiko * Append new BTF_KIND_ENUM type with: 20074a3b33f8SAndrii Nakryiko * - *name* - name of the enum, can be NULL or empty for anonymous enums; 20084a3b33f8SAndrii Nakryiko * - *byte_sz* - size of the enum, in bytes. 20094a3b33f8SAndrii Nakryiko * 20104a3b33f8SAndrii Nakryiko * Enum initially has no enum values in it (and corresponds to enum forward 20114a3b33f8SAndrii Nakryiko * declaration). Enumerator values can be added by btf__add_enum_value() 20124a3b33f8SAndrii Nakryiko * immediately after btf__add_enum() succeeds. 20134a3b33f8SAndrii Nakryiko * 20144a3b33f8SAndrii Nakryiko * Returns: 20154a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 20164a3b33f8SAndrii Nakryiko * - <0, on error. 20174a3b33f8SAndrii Nakryiko */ 20184a3b33f8SAndrii Nakryiko int btf__add_enum(struct btf *btf, const char *name, __u32 byte_sz) 20194a3b33f8SAndrii Nakryiko { 20204a3b33f8SAndrii Nakryiko struct btf_type *t; 2021c81ed6d8SAndrii Nakryiko int sz, name_off = 0; 20224a3b33f8SAndrii Nakryiko 20234a3b33f8SAndrii Nakryiko /* byte_sz must be power of 2 */ 20244a3b33f8SAndrii Nakryiko if (!byte_sz || (byte_sz & (byte_sz - 1)) || byte_sz > 8) 2025e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 20264a3b33f8SAndrii Nakryiko 20274a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 2028e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 20294a3b33f8SAndrii Nakryiko 20304a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type); 20314a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 20324a3b33f8SAndrii Nakryiko if (!t) 2033e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 20344a3b33f8SAndrii Nakryiko 20354a3b33f8SAndrii Nakryiko if (name && name[0]) { 20364a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 20374a3b33f8SAndrii Nakryiko if (name_off < 0) 20384a3b33f8SAndrii Nakryiko return name_off; 20394a3b33f8SAndrii Nakryiko } 20404a3b33f8SAndrii Nakryiko 20414a3b33f8SAndrii Nakryiko /* start out with vlen=0; it will be adjusted when adding enum values */ 20424a3b33f8SAndrii Nakryiko t->name_off = name_off; 20434a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_ENUM, 0, 0); 20444a3b33f8SAndrii Nakryiko t->size = byte_sz; 20454a3b33f8SAndrii Nakryiko 2046c81ed6d8SAndrii Nakryiko return btf_commit_type(btf, sz); 20474a3b33f8SAndrii Nakryiko } 20484a3b33f8SAndrii Nakryiko 20494a3b33f8SAndrii Nakryiko /* 20504a3b33f8SAndrii Nakryiko * Append new enum value for the current ENUM type with: 20514a3b33f8SAndrii Nakryiko * - *name* - name of the enumerator value, can't be NULL or empty; 20524a3b33f8SAndrii Nakryiko * - *value* - integer value corresponding to enum value *name*; 20534a3b33f8SAndrii Nakryiko * Returns: 20544a3b33f8SAndrii Nakryiko * - 0, on success; 20554a3b33f8SAndrii Nakryiko * - <0, on error. 20564a3b33f8SAndrii Nakryiko */ 20574a3b33f8SAndrii Nakryiko int btf__add_enum_value(struct btf *btf, const char *name, __s64 value) 20584a3b33f8SAndrii Nakryiko { 20594a3b33f8SAndrii Nakryiko struct btf_type *t; 20604a3b33f8SAndrii Nakryiko struct btf_enum *v; 20614a3b33f8SAndrii Nakryiko int sz, name_off; 20624a3b33f8SAndrii Nakryiko 20634a3b33f8SAndrii Nakryiko /* last type should be BTF_KIND_ENUM */ 20644a3b33f8SAndrii Nakryiko if (btf->nr_types == 0) 2065e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 2066c81ed6d8SAndrii Nakryiko t = btf_last_type(btf); 20674a3b33f8SAndrii Nakryiko if (!btf_is_enum(t)) 2068e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 20694a3b33f8SAndrii Nakryiko 20704a3b33f8SAndrii Nakryiko /* non-empty name */ 20714a3b33f8SAndrii Nakryiko if (!name || !name[0]) 2072e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 20734a3b33f8SAndrii Nakryiko if (value < INT_MIN || value > UINT_MAX) 2074e9fc3ce9SAndrii Nakryiko return libbpf_err(-E2BIG); 20754a3b33f8SAndrii Nakryiko 20764a3b33f8SAndrii Nakryiko /* decompose and invalidate raw data */ 20774a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 2078e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 20794a3b33f8SAndrii Nakryiko 20804a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_enum); 20814a3b33f8SAndrii Nakryiko v = btf_add_type_mem(btf, sz); 20824a3b33f8SAndrii Nakryiko if (!v) 2083e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 20844a3b33f8SAndrii Nakryiko 20854a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 20864a3b33f8SAndrii Nakryiko if (name_off < 0) 20874a3b33f8SAndrii Nakryiko return name_off; 20884a3b33f8SAndrii Nakryiko 20894a3b33f8SAndrii Nakryiko v->name_off = name_off; 20904a3b33f8SAndrii Nakryiko v->val = value; 20914a3b33f8SAndrii Nakryiko 20924a3b33f8SAndrii Nakryiko /* update parent type's vlen */ 2093c81ed6d8SAndrii Nakryiko t = btf_last_type(btf); 20944a3b33f8SAndrii Nakryiko btf_type_inc_vlen(t); 20954a3b33f8SAndrii Nakryiko 20964a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 20974a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 20984a3b33f8SAndrii Nakryiko return 0; 20994a3b33f8SAndrii Nakryiko } 21004a3b33f8SAndrii Nakryiko 21014a3b33f8SAndrii Nakryiko /* 21024a3b33f8SAndrii Nakryiko * Append new BTF_KIND_FWD type with: 21034a3b33f8SAndrii Nakryiko * - *name*, non-empty/non-NULL name; 21044a3b33f8SAndrii Nakryiko * - *fwd_kind*, kind of forward declaration, one of BTF_FWD_STRUCT, 21054a3b33f8SAndrii Nakryiko * BTF_FWD_UNION, or BTF_FWD_ENUM; 21064a3b33f8SAndrii Nakryiko * Returns: 21074a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 21084a3b33f8SAndrii Nakryiko * - <0, on error. 21094a3b33f8SAndrii Nakryiko */ 21104a3b33f8SAndrii Nakryiko int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind) 21114a3b33f8SAndrii Nakryiko { 21124a3b33f8SAndrii Nakryiko if (!name || !name[0]) 2113e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 21144a3b33f8SAndrii Nakryiko 21154a3b33f8SAndrii Nakryiko switch (fwd_kind) { 21164a3b33f8SAndrii Nakryiko case BTF_FWD_STRUCT: 21174a3b33f8SAndrii Nakryiko case BTF_FWD_UNION: { 21184a3b33f8SAndrii Nakryiko struct btf_type *t; 21194a3b33f8SAndrii Nakryiko int id; 21204a3b33f8SAndrii Nakryiko 21214a3b33f8SAndrii Nakryiko id = btf_add_ref_kind(btf, BTF_KIND_FWD, name, 0); 21224a3b33f8SAndrii Nakryiko if (id <= 0) 21234a3b33f8SAndrii Nakryiko return id; 21244a3b33f8SAndrii Nakryiko t = btf_type_by_id(btf, id); 21254a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_FWD, 0, fwd_kind == BTF_FWD_UNION); 21264a3b33f8SAndrii Nakryiko return id; 21274a3b33f8SAndrii Nakryiko } 21284a3b33f8SAndrii Nakryiko case BTF_FWD_ENUM: 21294a3b33f8SAndrii Nakryiko /* enum forward in BTF currently is just an enum with no enum 21304a3b33f8SAndrii Nakryiko * values; we also assume a standard 4-byte size for it 21314a3b33f8SAndrii Nakryiko */ 21324a3b33f8SAndrii Nakryiko return btf__add_enum(btf, name, sizeof(int)); 21334a3b33f8SAndrii Nakryiko default: 2134e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 21354a3b33f8SAndrii Nakryiko } 21364a3b33f8SAndrii Nakryiko } 21374a3b33f8SAndrii Nakryiko 21384a3b33f8SAndrii Nakryiko /* 21394a3b33f8SAndrii Nakryiko * Append new BTF_KING_TYPEDEF type with: 21404a3b33f8SAndrii Nakryiko * - *name*, non-empty/non-NULL name; 21414a3b33f8SAndrii Nakryiko * - *ref_type_id* - referenced type ID, it might not exist yet; 21424a3b33f8SAndrii Nakryiko * Returns: 21434a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 21444a3b33f8SAndrii Nakryiko * - <0, on error. 21454a3b33f8SAndrii Nakryiko */ 21464a3b33f8SAndrii Nakryiko int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id) 21474a3b33f8SAndrii Nakryiko { 21484a3b33f8SAndrii Nakryiko if (!name || !name[0]) 2149e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 21504a3b33f8SAndrii Nakryiko 21514a3b33f8SAndrii Nakryiko return btf_add_ref_kind(btf, BTF_KIND_TYPEDEF, name, ref_type_id); 21524a3b33f8SAndrii Nakryiko } 21534a3b33f8SAndrii Nakryiko 21544a3b33f8SAndrii Nakryiko /* 21554a3b33f8SAndrii Nakryiko * Append new BTF_KIND_VOLATILE type with: 21564a3b33f8SAndrii Nakryiko * - *ref_type_id* - referenced type ID, it might not exist yet; 21574a3b33f8SAndrii Nakryiko * Returns: 21584a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 21594a3b33f8SAndrii Nakryiko * - <0, on error. 21604a3b33f8SAndrii Nakryiko */ 21614a3b33f8SAndrii Nakryiko int btf__add_volatile(struct btf *btf, int ref_type_id) 21624a3b33f8SAndrii Nakryiko { 21634a3b33f8SAndrii Nakryiko return btf_add_ref_kind(btf, BTF_KIND_VOLATILE, NULL, ref_type_id); 21644a3b33f8SAndrii Nakryiko } 21654a3b33f8SAndrii Nakryiko 21664a3b33f8SAndrii Nakryiko /* 21674a3b33f8SAndrii Nakryiko * Append new BTF_KIND_CONST type with: 21684a3b33f8SAndrii Nakryiko * - *ref_type_id* - referenced type ID, it might not exist yet; 21694a3b33f8SAndrii Nakryiko * Returns: 21704a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 21714a3b33f8SAndrii Nakryiko * - <0, on error. 21724a3b33f8SAndrii Nakryiko */ 21734a3b33f8SAndrii Nakryiko int btf__add_const(struct btf *btf, int ref_type_id) 21744a3b33f8SAndrii Nakryiko { 21754a3b33f8SAndrii Nakryiko return btf_add_ref_kind(btf, BTF_KIND_CONST, NULL, ref_type_id); 21764a3b33f8SAndrii Nakryiko } 21774a3b33f8SAndrii Nakryiko 21784a3b33f8SAndrii Nakryiko /* 21794a3b33f8SAndrii Nakryiko * Append new BTF_KIND_RESTRICT type with: 21804a3b33f8SAndrii Nakryiko * - *ref_type_id* - referenced type ID, it might not exist yet; 21814a3b33f8SAndrii Nakryiko * Returns: 21824a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 21834a3b33f8SAndrii Nakryiko * - <0, on error. 21844a3b33f8SAndrii Nakryiko */ 21854a3b33f8SAndrii Nakryiko int btf__add_restrict(struct btf *btf, int ref_type_id) 21864a3b33f8SAndrii Nakryiko { 21874a3b33f8SAndrii Nakryiko return btf_add_ref_kind(btf, BTF_KIND_RESTRICT, NULL, ref_type_id); 21884a3b33f8SAndrii Nakryiko } 21894a3b33f8SAndrii Nakryiko 21904a3b33f8SAndrii Nakryiko /* 21914a3b33f8SAndrii Nakryiko * Append new BTF_KIND_FUNC type with: 21924a3b33f8SAndrii Nakryiko * - *name*, non-empty/non-NULL name; 21934a3b33f8SAndrii Nakryiko * - *proto_type_id* - FUNC_PROTO's type ID, it might not exist yet; 21944a3b33f8SAndrii Nakryiko * Returns: 21954a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 21964a3b33f8SAndrii Nakryiko * - <0, on error. 21974a3b33f8SAndrii Nakryiko */ 21984a3b33f8SAndrii Nakryiko int btf__add_func(struct btf *btf, const char *name, 21994a3b33f8SAndrii Nakryiko enum btf_func_linkage linkage, int proto_type_id) 22004a3b33f8SAndrii Nakryiko { 22014a3b33f8SAndrii Nakryiko int id; 22024a3b33f8SAndrii Nakryiko 22034a3b33f8SAndrii Nakryiko if (!name || !name[0]) 2204e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 22054a3b33f8SAndrii Nakryiko if (linkage != BTF_FUNC_STATIC && linkage != BTF_FUNC_GLOBAL && 22064a3b33f8SAndrii Nakryiko linkage != BTF_FUNC_EXTERN) 2207e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 22084a3b33f8SAndrii Nakryiko 22094a3b33f8SAndrii Nakryiko id = btf_add_ref_kind(btf, BTF_KIND_FUNC, name, proto_type_id); 22104a3b33f8SAndrii Nakryiko if (id > 0) { 22114a3b33f8SAndrii Nakryiko struct btf_type *t = btf_type_by_id(btf, id); 22124a3b33f8SAndrii Nakryiko 22134a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_FUNC, linkage, 0); 22144a3b33f8SAndrii Nakryiko } 2215e9fc3ce9SAndrii Nakryiko return libbpf_err(id); 22164a3b33f8SAndrii Nakryiko } 22174a3b33f8SAndrii Nakryiko 22184a3b33f8SAndrii Nakryiko /* 22194a3b33f8SAndrii Nakryiko * Append new BTF_KIND_FUNC_PROTO with: 22204a3b33f8SAndrii Nakryiko * - *ret_type_id* - type ID for return result of a function. 22214a3b33f8SAndrii Nakryiko * 22224a3b33f8SAndrii Nakryiko * Function prototype initially has no arguments, but they can be added by 22234a3b33f8SAndrii Nakryiko * btf__add_func_param() one by one, immediately after 22244a3b33f8SAndrii Nakryiko * btf__add_func_proto() succeeded. 22254a3b33f8SAndrii Nakryiko * 22264a3b33f8SAndrii Nakryiko * Returns: 22274a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 22284a3b33f8SAndrii Nakryiko * - <0, on error. 22294a3b33f8SAndrii Nakryiko */ 22304a3b33f8SAndrii Nakryiko int btf__add_func_proto(struct btf *btf, int ret_type_id) 22314a3b33f8SAndrii Nakryiko { 22324a3b33f8SAndrii Nakryiko struct btf_type *t; 2233c81ed6d8SAndrii Nakryiko int sz; 22344a3b33f8SAndrii Nakryiko 22354a3b33f8SAndrii Nakryiko if (validate_type_id(ret_type_id)) 2236e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 22374a3b33f8SAndrii Nakryiko 22384a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 2239e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 22404a3b33f8SAndrii Nakryiko 22414a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type); 22424a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 22434a3b33f8SAndrii Nakryiko if (!t) 2244e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 22454a3b33f8SAndrii Nakryiko 22464a3b33f8SAndrii Nakryiko /* start out with vlen=0; this will be adjusted when adding enum 22474a3b33f8SAndrii Nakryiko * values, if necessary 22484a3b33f8SAndrii Nakryiko */ 22494a3b33f8SAndrii Nakryiko t->name_off = 0; 22504a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_FUNC_PROTO, 0, 0); 22514a3b33f8SAndrii Nakryiko t->type = ret_type_id; 22524a3b33f8SAndrii Nakryiko 2253c81ed6d8SAndrii Nakryiko return btf_commit_type(btf, sz); 22544a3b33f8SAndrii Nakryiko } 22554a3b33f8SAndrii Nakryiko 22564a3b33f8SAndrii Nakryiko /* 22574a3b33f8SAndrii Nakryiko * Append new function parameter for current FUNC_PROTO type with: 22584a3b33f8SAndrii Nakryiko * - *name* - parameter name, can be NULL or empty; 22594a3b33f8SAndrii Nakryiko * - *type_id* - type ID describing the type of the parameter. 22604a3b33f8SAndrii Nakryiko * Returns: 22614a3b33f8SAndrii Nakryiko * - 0, on success; 22624a3b33f8SAndrii Nakryiko * - <0, on error. 22634a3b33f8SAndrii Nakryiko */ 22644a3b33f8SAndrii Nakryiko int btf__add_func_param(struct btf *btf, const char *name, int type_id) 22654a3b33f8SAndrii Nakryiko { 22664a3b33f8SAndrii Nakryiko struct btf_type *t; 22674a3b33f8SAndrii Nakryiko struct btf_param *p; 22684a3b33f8SAndrii Nakryiko int sz, name_off = 0; 22694a3b33f8SAndrii Nakryiko 22704a3b33f8SAndrii Nakryiko if (validate_type_id(type_id)) 2271e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 22724a3b33f8SAndrii Nakryiko 22734a3b33f8SAndrii Nakryiko /* last type should be BTF_KIND_FUNC_PROTO */ 22744a3b33f8SAndrii Nakryiko if (btf->nr_types == 0) 2275e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 2276c81ed6d8SAndrii Nakryiko t = btf_last_type(btf); 22774a3b33f8SAndrii Nakryiko if (!btf_is_func_proto(t)) 2278e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 22794a3b33f8SAndrii Nakryiko 22804a3b33f8SAndrii Nakryiko /* decompose and invalidate raw data */ 22814a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 2282e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 22834a3b33f8SAndrii Nakryiko 22844a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_param); 22854a3b33f8SAndrii Nakryiko p = btf_add_type_mem(btf, sz); 22864a3b33f8SAndrii Nakryiko if (!p) 2287e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 22884a3b33f8SAndrii Nakryiko 22894a3b33f8SAndrii Nakryiko if (name && name[0]) { 22904a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 22914a3b33f8SAndrii Nakryiko if (name_off < 0) 22924a3b33f8SAndrii Nakryiko return name_off; 22934a3b33f8SAndrii Nakryiko } 22944a3b33f8SAndrii Nakryiko 22954a3b33f8SAndrii Nakryiko p->name_off = name_off; 22964a3b33f8SAndrii Nakryiko p->type = type_id; 22974a3b33f8SAndrii Nakryiko 22984a3b33f8SAndrii Nakryiko /* update parent type's vlen */ 2299c81ed6d8SAndrii Nakryiko t = btf_last_type(btf); 23004a3b33f8SAndrii Nakryiko btf_type_inc_vlen(t); 23014a3b33f8SAndrii Nakryiko 23024a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 23034a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 23044a3b33f8SAndrii Nakryiko return 0; 23054a3b33f8SAndrii Nakryiko } 23064a3b33f8SAndrii Nakryiko 23074a3b33f8SAndrii Nakryiko /* 23084a3b33f8SAndrii Nakryiko * Append new BTF_KIND_VAR type with: 23094a3b33f8SAndrii Nakryiko * - *name* - non-empty/non-NULL name; 23104a3b33f8SAndrii Nakryiko * - *linkage* - variable linkage, one of BTF_VAR_STATIC, 23114a3b33f8SAndrii Nakryiko * BTF_VAR_GLOBAL_ALLOCATED, or BTF_VAR_GLOBAL_EXTERN; 23124a3b33f8SAndrii Nakryiko * - *type_id* - type ID of the type describing the type of the variable. 23134a3b33f8SAndrii Nakryiko * Returns: 23144a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 23154a3b33f8SAndrii Nakryiko * - <0, on error. 23164a3b33f8SAndrii Nakryiko */ 23174a3b33f8SAndrii Nakryiko int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id) 23184a3b33f8SAndrii Nakryiko { 23194a3b33f8SAndrii Nakryiko struct btf_type *t; 23204a3b33f8SAndrii Nakryiko struct btf_var *v; 2321c81ed6d8SAndrii Nakryiko int sz, name_off; 23224a3b33f8SAndrii Nakryiko 23234a3b33f8SAndrii Nakryiko /* non-empty name */ 23244a3b33f8SAndrii Nakryiko if (!name || !name[0]) 2325e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 23264a3b33f8SAndrii Nakryiko if (linkage != BTF_VAR_STATIC && linkage != BTF_VAR_GLOBAL_ALLOCATED && 23274a3b33f8SAndrii Nakryiko linkage != BTF_VAR_GLOBAL_EXTERN) 2328e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 23294a3b33f8SAndrii Nakryiko if (validate_type_id(type_id)) 2330e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 23314a3b33f8SAndrii Nakryiko 23324a3b33f8SAndrii Nakryiko /* deconstruct BTF, if necessary, and invalidate raw_data */ 23334a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 2334e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 23354a3b33f8SAndrii Nakryiko 23364a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type) + sizeof(struct btf_var); 23374a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 23384a3b33f8SAndrii Nakryiko if (!t) 2339e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 23404a3b33f8SAndrii Nakryiko 23414a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 23424a3b33f8SAndrii Nakryiko if (name_off < 0) 23434a3b33f8SAndrii Nakryiko return name_off; 23444a3b33f8SAndrii Nakryiko 23454a3b33f8SAndrii Nakryiko t->name_off = name_off; 23464a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_VAR, 0, 0); 23474a3b33f8SAndrii Nakryiko t->type = type_id; 23484a3b33f8SAndrii Nakryiko 23494a3b33f8SAndrii Nakryiko v = btf_var(t); 23504a3b33f8SAndrii Nakryiko v->linkage = linkage; 23514a3b33f8SAndrii Nakryiko 2352c81ed6d8SAndrii Nakryiko return btf_commit_type(btf, sz); 23534a3b33f8SAndrii Nakryiko } 23544a3b33f8SAndrii Nakryiko 23554a3b33f8SAndrii Nakryiko /* 23564a3b33f8SAndrii Nakryiko * Append new BTF_KIND_DATASEC type with: 23574a3b33f8SAndrii Nakryiko * - *name* - non-empty/non-NULL name; 23584a3b33f8SAndrii Nakryiko * - *byte_sz* - data section size, in bytes. 23594a3b33f8SAndrii Nakryiko * 23604a3b33f8SAndrii Nakryiko * Data section is initially empty. Variables info can be added with 23614a3b33f8SAndrii Nakryiko * btf__add_datasec_var_info() calls, after btf__add_datasec() succeeds. 23624a3b33f8SAndrii Nakryiko * 23634a3b33f8SAndrii Nakryiko * Returns: 23644a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 23654a3b33f8SAndrii Nakryiko * - <0, on error. 23664a3b33f8SAndrii Nakryiko */ 23674a3b33f8SAndrii Nakryiko int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz) 23684a3b33f8SAndrii Nakryiko { 23694a3b33f8SAndrii Nakryiko struct btf_type *t; 2370c81ed6d8SAndrii Nakryiko int sz, name_off; 23714a3b33f8SAndrii Nakryiko 23724a3b33f8SAndrii Nakryiko /* non-empty name */ 23734a3b33f8SAndrii Nakryiko if (!name || !name[0]) 2374e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 23754a3b33f8SAndrii Nakryiko 23764a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 2377e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 23784a3b33f8SAndrii Nakryiko 23794a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type); 23804a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 23814a3b33f8SAndrii Nakryiko if (!t) 2382e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 23834a3b33f8SAndrii Nakryiko 23844a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 23854a3b33f8SAndrii Nakryiko if (name_off < 0) 23864a3b33f8SAndrii Nakryiko return name_off; 23874a3b33f8SAndrii Nakryiko 23884a3b33f8SAndrii Nakryiko /* start with vlen=0, which will be update as var_secinfos are added */ 23894a3b33f8SAndrii Nakryiko t->name_off = name_off; 23904a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_DATASEC, 0, 0); 23914a3b33f8SAndrii Nakryiko t->size = byte_sz; 23924a3b33f8SAndrii Nakryiko 2393c81ed6d8SAndrii Nakryiko return btf_commit_type(btf, sz); 23944a3b33f8SAndrii Nakryiko } 23954a3b33f8SAndrii Nakryiko 23964a3b33f8SAndrii Nakryiko /* 23974a3b33f8SAndrii Nakryiko * Append new data section variable information entry for current DATASEC type: 23984a3b33f8SAndrii Nakryiko * - *var_type_id* - type ID, describing type of the variable; 23994a3b33f8SAndrii Nakryiko * - *offset* - variable offset within data section, in bytes; 24004a3b33f8SAndrii Nakryiko * - *byte_sz* - variable size, in bytes. 24014a3b33f8SAndrii Nakryiko * 24024a3b33f8SAndrii Nakryiko * Returns: 24034a3b33f8SAndrii Nakryiko * - 0, on success; 24044a3b33f8SAndrii Nakryiko * - <0, on error. 24054a3b33f8SAndrii Nakryiko */ 24064a3b33f8SAndrii Nakryiko int btf__add_datasec_var_info(struct btf *btf, int var_type_id, __u32 offset, __u32 byte_sz) 24074a3b33f8SAndrii Nakryiko { 24084a3b33f8SAndrii Nakryiko struct btf_type *t; 24094a3b33f8SAndrii Nakryiko struct btf_var_secinfo *v; 24104a3b33f8SAndrii Nakryiko int sz; 24114a3b33f8SAndrii Nakryiko 24124a3b33f8SAndrii Nakryiko /* last type should be BTF_KIND_DATASEC */ 24134a3b33f8SAndrii Nakryiko if (btf->nr_types == 0) 2414e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 2415c81ed6d8SAndrii Nakryiko t = btf_last_type(btf); 24164a3b33f8SAndrii Nakryiko if (!btf_is_datasec(t)) 2417e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 24184a3b33f8SAndrii Nakryiko 24194a3b33f8SAndrii Nakryiko if (validate_type_id(var_type_id)) 2420e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 24214a3b33f8SAndrii Nakryiko 24224a3b33f8SAndrii Nakryiko /* decompose and invalidate raw data */ 24234a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 2424e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 24254a3b33f8SAndrii Nakryiko 24264a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_var_secinfo); 24274a3b33f8SAndrii Nakryiko v = btf_add_type_mem(btf, sz); 24284a3b33f8SAndrii Nakryiko if (!v) 2429e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 24304a3b33f8SAndrii Nakryiko 24314a3b33f8SAndrii Nakryiko v->type = var_type_id; 24324a3b33f8SAndrii Nakryiko v->offset = offset; 24334a3b33f8SAndrii Nakryiko v->size = byte_sz; 24344a3b33f8SAndrii Nakryiko 24354a3b33f8SAndrii Nakryiko /* update parent type's vlen */ 2436c81ed6d8SAndrii Nakryiko t = btf_last_type(btf); 24374a3b33f8SAndrii Nakryiko btf_type_inc_vlen(t); 24384a3b33f8SAndrii Nakryiko 24394a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 24404a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 24414a3b33f8SAndrii Nakryiko return 0; 24424a3b33f8SAndrii Nakryiko } 24434a3b33f8SAndrii Nakryiko 2444ae4ab4b4SAndrii Nakryiko struct btf_ext_sec_setup_param { 24453d650141SMartin KaFai Lau __u32 off; 24463d650141SMartin KaFai Lau __u32 len; 24473d650141SMartin KaFai Lau __u32 min_rec_size; 24483d650141SMartin KaFai Lau struct btf_ext_info *ext_info; 24493d650141SMartin KaFai Lau const char *desc; 24503d650141SMartin KaFai Lau }; 24513d650141SMartin KaFai Lau 2452ae4ab4b4SAndrii Nakryiko static int btf_ext_setup_info(struct btf_ext *btf_ext, 2453ae4ab4b4SAndrii Nakryiko struct btf_ext_sec_setup_param *ext_sec) 24542993e051SYonghong Song { 24553d650141SMartin KaFai Lau const struct btf_ext_info_sec *sinfo; 24563d650141SMartin KaFai Lau struct btf_ext_info *ext_info; 2457f0187f0bSMartin KaFai Lau __u32 info_left, record_size; 2458f0187f0bSMartin KaFai Lau /* The start of the info sec (including the __u32 record_size). */ 2459ae4ab4b4SAndrii Nakryiko void *info; 2460f0187f0bSMartin KaFai Lau 24614cedc0daSAndrii Nakryiko if (ext_sec->len == 0) 24624cedc0daSAndrii Nakryiko return 0; 24634cedc0daSAndrii Nakryiko 24643d650141SMartin KaFai Lau if (ext_sec->off & 0x03) { 24658461ef8bSYonghong Song pr_debug(".BTF.ext %s section is not aligned to 4 bytes\n", 24663d650141SMartin KaFai Lau ext_sec->desc); 2467f0187f0bSMartin KaFai Lau return -EINVAL; 2468f0187f0bSMartin KaFai Lau } 2469f0187f0bSMartin KaFai Lau 2470ae4ab4b4SAndrii Nakryiko info = btf_ext->data + btf_ext->hdr->hdr_len + ext_sec->off; 2471ae4ab4b4SAndrii Nakryiko info_left = ext_sec->len; 2472ae4ab4b4SAndrii Nakryiko 2473ae4ab4b4SAndrii Nakryiko if (btf_ext->data + btf_ext->data_size < info + ext_sec->len) { 24748461ef8bSYonghong Song pr_debug("%s section (off:%u len:%u) is beyond the end of the ELF section .BTF.ext\n", 24753d650141SMartin KaFai Lau ext_sec->desc, ext_sec->off, ext_sec->len); 2476f0187f0bSMartin KaFai Lau return -EINVAL; 2477f0187f0bSMartin KaFai Lau } 2478f0187f0bSMartin KaFai Lau 24793d650141SMartin KaFai Lau /* At least a record size */ 2480f0187f0bSMartin KaFai Lau if (info_left < sizeof(__u32)) { 24818461ef8bSYonghong Song pr_debug(".BTF.ext %s record size not found\n", ext_sec->desc); 24822993e051SYonghong Song return -EINVAL; 24832993e051SYonghong Song } 24842993e051SYonghong Song 2485f0187f0bSMartin KaFai Lau /* The record size needs to meet the minimum standard */ 2486f0187f0bSMartin KaFai Lau record_size = *(__u32 *)info; 24873d650141SMartin KaFai Lau if (record_size < ext_sec->min_rec_size || 2488f0187f0bSMartin KaFai Lau record_size & 0x03) { 24898461ef8bSYonghong Song pr_debug("%s section in .BTF.ext has invalid record size %u\n", 24903d650141SMartin KaFai Lau ext_sec->desc, record_size); 24912993e051SYonghong Song return -EINVAL; 24922993e051SYonghong Song } 24932993e051SYonghong Song 2494f0187f0bSMartin KaFai Lau sinfo = info + sizeof(__u32); 2495f0187f0bSMartin KaFai Lau info_left -= sizeof(__u32); 24962993e051SYonghong Song 24973d650141SMartin KaFai Lau /* If no records, return failure now so .BTF.ext won't be used. */ 2498f0187f0bSMartin KaFai Lau if (!info_left) { 24998461ef8bSYonghong Song pr_debug("%s section in .BTF.ext has no records", ext_sec->desc); 25002993e051SYonghong Song return -EINVAL; 25012993e051SYonghong Song } 25022993e051SYonghong Song 2503f0187f0bSMartin KaFai Lau while (info_left) { 25043d650141SMartin KaFai Lau unsigned int sec_hdrlen = sizeof(struct btf_ext_info_sec); 2505f0187f0bSMartin KaFai Lau __u64 total_record_size; 2506f0187f0bSMartin KaFai Lau __u32 num_records; 2507f0187f0bSMartin KaFai Lau 2508f0187f0bSMartin KaFai Lau if (info_left < sec_hdrlen) { 25098461ef8bSYonghong Song pr_debug("%s section header is not found in .BTF.ext\n", 25103d650141SMartin KaFai Lau ext_sec->desc); 25112993e051SYonghong Song return -EINVAL; 25122993e051SYonghong Song } 25132993e051SYonghong Song 25143d650141SMartin KaFai Lau num_records = sinfo->num_info; 25152993e051SYonghong Song if (num_records == 0) { 25168461ef8bSYonghong Song pr_debug("%s section has incorrect num_records in .BTF.ext\n", 25173d650141SMartin KaFai Lau ext_sec->desc); 25182993e051SYonghong Song return -EINVAL; 25192993e051SYonghong Song } 25202993e051SYonghong Song 25212993e051SYonghong Song total_record_size = sec_hdrlen + 25222993e051SYonghong Song (__u64)num_records * record_size; 2523f0187f0bSMartin KaFai Lau if (info_left < total_record_size) { 25248461ef8bSYonghong Song pr_debug("%s section has incorrect num_records in .BTF.ext\n", 25253d650141SMartin KaFai Lau ext_sec->desc); 25262993e051SYonghong Song return -EINVAL; 25272993e051SYonghong Song } 25282993e051SYonghong Song 2529f0187f0bSMartin KaFai Lau info_left -= total_record_size; 25302993e051SYonghong Song sinfo = (void *)sinfo + total_record_size; 25312993e051SYonghong Song } 25322993e051SYonghong Song 25333d650141SMartin KaFai Lau ext_info = ext_sec->ext_info; 25343d650141SMartin KaFai Lau ext_info->len = ext_sec->len - sizeof(__u32); 25353d650141SMartin KaFai Lau ext_info->rec_size = record_size; 2536ae4ab4b4SAndrii Nakryiko ext_info->info = info + sizeof(__u32); 2537f0187f0bSMartin KaFai Lau 25382993e051SYonghong Song return 0; 25392993e051SYonghong Song } 25402993e051SYonghong Song 2541ae4ab4b4SAndrii Nakryiko static int btf_ext_setup_func_info(struct btf_ext *btf_ext) 25423d650141SMartin KaFai Lau { 2543ae4ab4b4SAndrii Nakryiko struct btf_ext_sec_setup_param param = { 2544ae4ab4b4SAndrii Nakryiko .off = btf_ext->hdr->func_info_off, 2545ae4ab4b4SAndrii Nakryiko .len = btf_ext->hdr->func_info_len, 25463d650141SMartin KaFai Lau .min_rec_size = sizeof(struct bpf_func_info_min), 25473d650141SMartin KaFai Lau .ext_info = &btf_ext->func_info, 25483d650141SMartin KaFai Lau .desc = "func_info" 25493d650141SMartin KaFai Lau }; 25503d650141SMartin KaFai Lau 2551ae4ab4b4SAndrii Nakryiko return btf_ext_setup_info(btf_ext, ¶m); 25523d650141SMartin KaFai Lau } 25533d650141SMartin KaFai Lau 2554ae4ab4b4SAndrii Nakryiko static int btf_ext_setup_line_info(struct btf_ext *btf_ext) 25553d650141SMartin KaFai Lau { 2556ae4ab4b4SAndrii Nakryiko struct btf_ext_sec_setup_param param = { 2557ae4ab4b4SAndrii Nakryiko .off = btf_ext->hdr->line_info_off, 2558ae4ab4b4SAndrii Nakryiko .len = btf_ext->hdr->line_info_len, 25593d650141SMartin KaFai Lau .min_rec_size = sizeof(struct bpf_line_info_min), 25603d650141SMartin KaFai Lau .ext_info = &btf_ext->line_info, 25613d650141SMartin KaFai Lau .desc = "line_info", 25623d650141SMartin KaFai Lau }; 25633d650141SMartin KaFai Lau 2564ae4ab4b4SAndrii Nakryiko return btf_ext_setup_info(btf_ext, ¶m); 25653d650141SMartin KaFai Lau } 25663d650141SMartin KaFai Lau 256728b93c64SAndrii Nakryiko static int btf_ext_setup_core_relos(struct btf_ext *btf_ext) 25684cedc0daSAndrii Nakryiko { 25694cedc0daSAndrii Nakryiko struct btf_ext_sec_setup_param param = { 257028b93c64SAndrii Nakryiko .off = btf_ext->hdr->core_relo_off, 257128b93c64SAndrii Nakryiko .len = btf_ext->hdr->core_relo_len, 257228b93c64SAndrii Nakryiko .min_rec_size = sizeof(struct bpf_core_relo), 257328b93c64SAndrii Nakryiko .ext_info = &btf_ext->core_relo_info, 257428b93c64SAndrii Nakryiko .desc = "core_relo", 25754cedc0daSAndrii Nakryiko }; 25764cedc0daSAndrii Nakryiko 25774cedc0daSAndrii Nakryiko return btf_ext_setup_info(btf_ext, ¶m); 25784cedc0daSAndrii Nakryiko } 25794cedc0daSAndrii Nakryiko 25808461ef8bSYonghong Song static int btf_ext_parse_hdr(__u8 *data, __u32 data_size) 25812993e051SYonghong Song { 25822993e051SYonghong Song const struct btf_ext_header *hdr = (struct btf_ext_header *)data; 25832993e051SYonghong Song 25844cedc0daSAndrii Nakryiko if (data_size < offsetofend(struct btf_ext_header, hdr_len) || 25852993e051SYonghong Song data_size < hdr->hdr_len) { 25868461ef8bSYonghong Song pr_debug("BTF.ext header not found"); 25872993e051SYonghong Song return -EINVAL; 25882993e051SYonghong Song } 25892993e051SYonghong Song 25903289959bSAndrii Nakryiko if (hdr->magic == bswap_16(BTF_MAGIC)) { 25913289959bSAndrii Nakryiko pr_warn("BTF.ext in non-native endianness is not supported\n"); 25923289959bSAndrii Nakryiko return -ENOTSUP; 25933289959bSAndrii Nakryiko } else if (hdr->magic != BTF_MAGIC) { 25948461ef8bSYonghong Song pr_debug("Invalid BTF.ext magic:%x\n", hdr->magic); 25952993e051SYonghong Song return -EINVAL; 25962993e051SYonghong Song } 25972993e051SYonghong Song 25982993e051SYonghong Song if (hdr->version != BTF_VERSION) { 25998461ef8bSYonghong Song pr_debug("Unsupported BTF.ext version:%u\n", hdr->version); 26002993e051SYonghong Song return -ENOTSUP; 26012993e051SYonghong Song } 26022993e051SYonghong Song 26032993e051SYonghong Song if (hdr->flags) { 26048461ef8bSYonghong Song pr_debug("Unsupported BTF.ext flags:%x\n", hdr->flags); 26052993e051SYonghong Song return -ENOTSUP; 26062993e051SYonghong Song } 26072993e051SYonghong Song 2608f0187f0bSMartin KaFai Lau if (data_size == hdr->hdr_len) { 26098461ef8bSYonghong Song pr_debug("BTF.ext has no data\n"); 26102993e051SYonghong Song return -EINVAL; 26112993e051SYonghong Song } 26122993e051SYonghong Song 2613f0187f0bSMartin KaFai Lau return 0; 26142993e051SYonghong Song } 26152993e051SYonghong Song 26162993e051SYonghong Song void btf_ext__free(struct btf_ext *btf_ext) 26172993e051SYonghong Song { 261850450fc7SAndrii Nakryiko if (IS_ERR_OR_NULL(btf_ext)) 26192993e051SYonghong Song return; 2620ae4ab4b4SAndrii Nakryiko free(btf_ext->data); 26212993e051SYonghong Song free(btf_ext); 26222993e051SYonghong Song } 26232993e051SYonghong Song 26248461ef8bSYonghong Song struct btf_ext *btf_ext__new(__u8 *data, __u32 size) 26252993e051SYonghong Song { 26262993e051SYonghong Song struct btf_ext *btf_ext; 26272993e051SYonghong Song int err; 26282993e051SYonghong Song 26298461ef8bSYonghong Song err = btf_ext_parse_hdr(data, size); 26302993e051SYonghong Song if (err) 2631e9fc3ce9SAndrii Nakryiko return libbpf_err_ptr(err); 26322993e051SYonghong Song 26332993e051SYonghong Song btf_ext = calloc(1, sizeof(struct btf_ext)); 26342993e051SYonghong Song if (!btf_ext) 2635e9fc3ce9SAndrii Nakryiko return libbpf_err_ptr(-ENOMEM); 26362993e051SYonghong Song 2637ae4ab4b4SAndrii Nakryiko btf_ext->data_size = size; 2638ae4ab4b4SAndrii Nakryiko btf_ext->data = malloc(size); 2639ae4ab4b4SAndrii Nakryiko if (!btf_ext->data) { 2640ae4ab4b4SAndrii Nakryiko err = -ENOMEM; 2641ae4ab4b4SAndrii Nakryiko goto done; 26422993e051SYonghong Song } 2643ae4ab4b4SAndrii Nakryiko memcpy(btf_ext->data, data, size); 26442993e051SYonghong Song 2645e9fc3ce9SAndrii Nakryiko if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, line_info_len)) { 2646e9fc3ce9SAndrii Nakryiko err = -EINVAL; 26474cedc0daSAndrii Nakryiko goto done; 2648e9fc3ce9SAndrii Nakryiko } 2649e9fc3ce9SAndrii Nakryiko 2650ae4ab4b4SAndrii Nakryiko err = btf_ext_setup_func_info(btf_ext); 2651ae4ab4b4SAndrii Nakryiko if (err) 2652ae4ab4b4SAndrii Nakryiko goto done; 2653ae4ab4b4SAndrii Nakryiko 2654ae4ab4b4SAndrii Nakryiko err = btf_ext_setup_line_info(btf_ext); 2655ae4ab4b4SAndrii Nakryiko if (err) 2656ae4ab4b4SAndrii Nakryiko goto done; 2657ae4ab4b4SAndrii Nakryiko 2658e9fc3ce9SAndrii Nakryiko if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, core_relo_len)) { 2659e9fc3ce9SAndrii Nakryiko err = -EINVAL; 26604cedc0daSAndrii Nakryiko goto done; 2661e9fc3ce9SAndrii Nakryiko } 2662e9fc3ce9SAndrii Nakryiko 266328b93c64SAndrii Nakryiko err = btf_ext_setup_core_relos(btf_ext); 26644cedc0daSAndrii Nakryiko if (err) 26654cedc0daSAndrii Nakryiko goto done; 26664cedc0daSAndrii Nakryiko 2667ae4ab4b4SAndrii Nakryiko done: 26683d650141SMartin KaFai Lau if (err) { 26693d650141SMartin KaFai Lau btf_ext__free(btf_ext); 2670e9fc3ce9SAndrii Nakryiko return libbpf_err_ptr(err); 26713d650141SMartin KaFai Lau } 26723d650141SMartin KaFai Lau 26732993e051SYonghong Song return btf_ext; 26742993e051SYonghong Song } 26752993e051SYonghong Song 2676ae4ab4b4SAndrii Nakryiko const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, __u32 *size) 2677ae4ab4b4SAndrii Nakryiko { 2678ae4ab4b4SAndrii Nakryiko *size = btf_ext->data_size; 2679ae4ab4b4SAndrii Nakryiko return btf_ext->data; 2680ae4ab4b4SAndrii Nakryiko } 2681ae4ab4b4SAndrii Nakryiko 26823d650141SMartin KaFai Lau static int btf_ext_reloc_info(const struct btf *btf, 26833d650141SMartin KaFai Lau const struct btf_ext_info *ext_info, 26842993e051SYonghong Song const char *sec_name, __u32 insns_cnt, 26853d650141SMartin KaFai Lau void **info, __u32 *cnt) 26862993e051SYonghong Song { 26873d650141SMartin KaFai Lau __u32 sec_hdrlen = sizeof(struct btf_ext_info_sec); 26883d650141SMartin KaFai Lau __u32 i, record_size, existing_len, records_len; 26893d650141SMartin KaFai Lau struct btf_ext_info_sec *sinfo; 26902993e051SYonghong Song const char *info_sec_name; 26912993e051SYonghong Song __u64 remain_len; 26922993e051SYonghong Song void *data; 26932993e051SYonghong Song 26943d650141SMartin KaFai Lau record_size = ext_info->rec_size; 26953d650141SMartin KaFai Lau sinfo = ext_info->info; 26963d650141SMartin KaFai Lau remain_len = ext_info->len; 26972993e051SYonghong Song while (remain_len > 0) { 26983d650141SMartin KaFai Lau records_len = sinfo->num_info * record_size; 26992993e051SYonghong Song info_sec_name = btf__name_by_offset(btf, sinfo->sec_name_off); 27002993e051SYonghong Song if (strcmp(info_sec_name, sec_name)) { 27012993e051SYonghong Song remain_len -= sec_hdrlen + records_len; 27022993e051SYonghong Song sinfo = (void *)sinfo + sec_hdrlen + records_len; 27032993e051SYonghong Song continue; 27042993e051SYonghong Song } 27052993e051SYonghong Song 27063d650141SMartin KaFai Lau existing_len = (*cnt) * record_size; 27073d650141SMartin KaFai Lau data = realloc(*info, existing_len + records_len); 27082993e051SYonghong Song if (!data) 2709e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 27102993e051SYonghong Song 27113d650141SMartin KaFai Lau memcpy(data + existing_len, sinfo->data, records_len); 271284ecc1f9SMartin KaFai Lau /* adjust insn_off only, the rest data will be passed 27132993e051SYonghong Song * to the kernel. 27142993e051SYonghong Song */ 27153d650141SMartin KaFai Lau for (i = 0; i < sinfo->num_info; i++) { 27163d650141SMartin KaFai Lau __u32 *insn_off; 27172993e051SYonghong Song 27183d650141SMartin KaFai Lau insn_off = data + existing_len + (i * record_size); 2719e9fc3ce9SAndrii Nakryiko *insn_off = *insn_off / sizeof(struct bpf_insn) + insns_cnt; 27202993e051SYonghong Song } 27213d650141SMartin KaFai Lau *info = data; 27223d650141SMartin KaFai Lau *cnt += sinfo->num_info; 27232993e051SYonghong Song return 0; 27242993e051SYonghong Song } 27252993e051SYonghong Song 2726e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOENT); 2727f0187f0bSMartin KaFai Lau } 2728f0187f0bSMartin KaFai Lau 2729ae4ab4b4SAndrii Nakryiko int btf_ext__reloc_func_info(const struct btf *btf, 2730ae4ab4b4SAndrii Nakryiko const struct btf_ext *btf_ext, 27313d650141SMartin KaFai Lau const char *sec_name, __u32 insns_cnt, 27323d650141SMartin KaFai Lau void **func_info, __u32 *cnt) 27333d650141SMartin KaFai Lau { 27343d650141SMartin KaFai Lau return btf_ext_reloc_info(btf, &btf_ext->func_info, sec_name, 27353d650141SMartin KaFai Lau insns_cnt, func_info, cnt); 27363d650141SMartin KaFai Lau } 27373d650141SMartin KaFai Lau 2738ae4ab4b4SAndrii Nakryiko int btf_ext__reloc_line_info(const struct btf *btf, 2739ae4ab4b4SAndrii Nakryiko const struct btf_ext *btf_ext, 27403d650141SMartin KaFai Lau const char *sec_name, __u32 insns_cnt, 27413d650141SMartin KaFai Lau void **line_info, __u32 *cnt) 27423d650141SMartin KaFai Lau { 27433d650141SMartin KaFai Lau return btf_ext_reloc_info(btf, &btf_ext->line_info, sec_name, 27443d650141SMartin KaFai Lau insns_cnt, line_info, cnt); 27453d650141SMartin KaFai Lau } 27463d650141SMartin KaFai Lau 2747f0187f0bSMartin KaFai Lau __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext) 2748f0187f0bSMartin KaFai Lau { 27493d650141SMartin KaFai Lau return btf_ext->func_info.rec_size; 27503d650141SMartin KaFai Lau } 27513d650141SMartin KaFai Lau 27523d650141SMartin KaFai Lau __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext) 27533d650141SMartin KaFai Lau { 27543d650141SMartin KaFai Lau return btf_ext->line_info.rec_size; 27552993e051SYonghong Song } 2756d5caef5bSAndrii Nakryiko 2757d5caef5bSAndrii Nakryiko struct btf_dedup; 2758d5caef5bSAndrii Nakryiko 2759d5caef5bSAndrii Nakryiko static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext, 2760d5caef5bSAndrii Nakryiko const struct btf_dedup_opts *opts); 2761d5caef5bSAndrii Nakryiko static void btf_dedup_free(struct btf_dedup *d); 2762f86524efSAndrii Nakryiko static int btf_dedup_prep(struct btf_dedup *d); 2763d5caef5bSAndrii Nakryiko static int btf_dedup_strings(struct btf_dedup *d); 2764d5caef5bSAndrii Nakryiko static int btf_dedup_prim_types(struct btf_dedup *d); 2765d5caef5bSAndrii Nakryiko static int btf_dedup_struct_types(struct btf_dedup *d); 2766d5caef5bSAndrii Nakryiko static int btf_dedup_ref_types(struct btf_dedup *d); 2767d5caef5bSAndrii Nakryiko static int btf_dedup_compact_types(struct btf_dedup *d); 2768d5caef5bSAndrii Nakryiko static int btf_dedup_remap_types(struct btf_dedup *d); 2769d5caef5bSAndrii Nakryiko 2770d5caef5bSAndrii Nakryiko /* 2771d5caef5bSAndrii Nakryiko * Deduplicate BTF types and strings. 2772d5caef5bSAndrii Nakryiko * 2773d5caef5bSAndrii Nakryiko * BTF dedup algorithm takes as an input `struct btf` representing `.BTF` ELF 2774d5caef5bSAndrii Nakryiko * section with all BTF type descriptors and string data. It overwrites that 2775d5caef5bSAndrii Nakryiko * memory in-place with deduplicated types and strings without any loss of 2776d5caef5bSAndrii Nakryiko * information. If optional `struct btf_ext` representing '.BTF.ext' ELF section 2777d5caef5bSAndrii Nakryiko * is provided, all the strings referenced from .BTF.ext section are honored 2778d5caef5bSAndrii Nakryiko * and updated to point to the right offsets after deduplication. 2779d5caef5bSAndrii Nakryiko * 2780d5caef5bSAndrii Nakryiko * If function returns with error, type/string data might be garbled and should 2781d5caef5bSAndrii Nakryiko * be discarded. 2782d5caef5bSAndrii Nakryiko * 2783d5caef5bSAndrii Nakryiko * More verbose and detailed description of both problem btf_dedup is solving, 2784d5caef5bSAndrii Nakryiko * as well as solution could be found at: 2785d5caef5bSAndrii Nakryiko * https://facebookmicrosites.github.io/bpf/blog/2018/11/14/btf-enhancement.html 2786d5caef5bSAndrii Nakryiko * 2787d5caef5bSAndrii Nakryiko * Problem description and justification 2788d5caef5bSAndrii Nakryiko * ===================================== 2789d5caef5bSAndrii Nakryiko * 2790d5caef5bSAndrii Nakryiko * BTF type information is typically emitted either as a result of conversion 2791d5caef5bSAndrii Nakryiko * from DWARF to BTF or directly by compiler. In both cases, each compilation 2792d5caef5bSAndrii Nakryiko * unit contains information about a subset of all the types that are used 2793d5caef5bSAndrii Nakryiko * in an application. These subsets are frequently overlapping and contain a lot 2794d5caef5bSAndrii Nakryiko * of duplicated information when later concatenated together into a single 2795d5caef5bSAndrii Nakryiko * binary. This algorithm ensures that each unique type is represented by single 2796d5caef5bSAndrii Nakryiko * BTF type descriptor, greatly reducing resulting size of BTF data. 2797d5caef5bSAndrii Nakryiko * 2798d5caef5bSAndrii Nakryiko * Compilation unit isolation and subsequent duplication of data is not the only 2799d5caef5bSAndrii Nakryiko * problem. The same type hierarchy (e.g., struct and all the type that struct 2800d5caef5bSAndrii Nakryiko * references) in different compilation units can be represented in BTF to 2801d5caef5bSAndrii Nakryiko * various degrees of completeness (or, rather, incompleteness) due to 2802d5caef5bSAndrii Nakryiko * struct/union forward declarations. 2803d5caef5bSAndrii Nakryiko * 2804d5caef5bSAndrii Nakryiko * Let's take a look at an example, that we'll use to better understand the 2805d5caef5bSAndrii Nakryiko * problem (and solution). Suppose we have two compilation units, each using 2806d5caef5bSAndrii Nakryiko * same `struct S`, but each of them having incomplete type information about 2807d5caef5bSAndrii Nakryiko * struct's fields: 2808d5caef5bSAndrii Nakryiko * 2809d5caef5bSAndrii Nakryiko * // CU #1: 2810d5caef5bSAndrii Nakryiko * struct S; 2811d5caef5bSAndrii Nakryiko * struct A { 2812d5caef5bSAndrii Nakryiko * int a; 2813d5caef5bSAndrii Nakryiko * struct A* self; 2814d5caef5bSAndrii Nakryiko * struct S* parent; 2815d5caef5bSAndrii Nakryiko * }; 2816d5caef5bSAndrii Nakryiko * struct B; 2817d5caef5bSAndrii Nakryiko * struct S { 2818d5caef5bSAndrii Nakryiko * struct A* a_ptr; 2819d5caef5bSAndrii Nakryiko * struct B* b_ptr; 2820d5caef5bSAndrii Nakryiko * }; 2821d5caef5bSAndrii Nakryiko * 2822d5caef5bSAndrii Nakryiko * // CU #2: 2823d5caef5bSAndrii Nakryiko * struct S; 2824d5caef5bSAndrii Nakryiko * struct A; 2825d5caef5bSAndrii Nakryiko * struct B { 2826d5caef5bSAndrii Nakryiko * int b; 2827d5caef5bSAndrii Nakryiko * struct B* self; 2828d5caef5bSAndrii Nakryiko * struct S* parent; 2829d5caef5bSAndrii Nakryiko * }; 2830d5caef5bSAndrii Nakryiko * struct S { 2831d5caef5bSAndrii Nakryiko * struct A* a_ptr; 2832d5caef5bSAndrii Nakryiko * struct B* b_ptr; 2833d5caef5bSAndrii Nakryiko * }; 2834d5caef5bSAndrii Nakryiko * 2835d5caef5bSAndrii Nakryiko * In case of CU #1, BTF data will know only that `struct B` exist (but no 2836d5caef5bSAndrii Nakryiko * more), but will know the complete type information about `struct A`. While 2837d5caef5bSAndrii Nakryiko * for CU #2, it will know full type information about `struct B`, but will 2838d5caef5bSAndrii Nakryiko * only know about forward declaration of `struct A` (in BTF terms, it will 2839d5caef5bSAndrii Nakryiko * have `BTF_KIND_FWD` type descriptor with name `B`). 2840d5caef5bSAndrii Nakryiko * 2841d5caef5bSAndrii Nakryiko * This compilation unit isolation means that it's possible that there is no 2842d5caef5bSAndrii Nakryiko * single CU with complete type information describing structs `S`, `A`, and 2843d5caef5bSAndrii Nakryiko * `B`. Also, we might get tons of duplicated and redundant type information. 2844d5caef5bSAndrii Nakryiko * 2845d5caef5bSAndrii Nakryiko * Additional complication we need to keep in mind comes from the fact that 2846d5caef5bSAndrii Nakryiko * types, in general, can form graphs containing cycles, not just DAGs. 2847d5caef5bSAndrii Nakryiko * 2848d5caef5bSAndrii Nakryiko * While algorithm does deduplication, it also merges and resolves type 2849d5caef5bSAndrii Nakryiko * information (unless disabled throught `struct btf_opts`), whenever possible. 2850d5caef5bSAndrii Nakryiko * E.g., in the example above with two compilation units having partial type 2851d5caef5bSAndrii Nakryiko * information for structs `A` and `B`, the output of algorithm will emit 2852d5caef5bSAndrii Nakryiko * a single copy of each BTF type that describes structs `A`, `B`, and `S` 2853d5caef5bSAndrii Nakryiko * (as well as type information for `int` and pointers), as if they were defined 2854d5caef5bSAndrii Nakryiko * in a single compilation unit as: 2855d5caef5bSAndrii Nakryiko * 2856d5caef5bSAndrii Nakryiko * struct A { 2857d5caef5bSAndrii Nakryiko * int a; 2858d5caef5bSAndrii Nakryiko * struct A* self; 2859d5caef5bSAndrii Nakryiko * struct S* parent; 2860d5caef5bSAndrii Nakryiko * }; 2861d5caef5bSAndrii Nakryiko * struct B { 2862d5caef5bSAndrii Nakryiko * int b; 2863d5caef5bSAndrii Nakryiko * struct B* self; 2864d5caef5bSAndrii Nakryiko * struct S* parent; 2865d5caef5bSAndrii Nakryiko * }; 2866d5caef5bSAndrii Nakryiko * struct S { 2867d5caef5bSAndrii Nakryiko * struct A* a_ptr; 2868d5caef5bSAndrii Nakryiko * struct B* b_ptr; 2869d5caef5bSAndrii Nakryiko * }; 2870d5caef5bSAndrii Nakryiko * 2871d5caef5bSAndrii Nakryiko * Algorithm summary 2872d5caef5bSAndrii Nakryiko * ================= 2873d5caef5bSAndrii Nakryiko * 2874d5caef5bSAndrii Nakryiko * Algorithm completes its work in 6 separate passes: 2875d5caef5bSAndrii Nakryiko * 2876d5caef5bSAndrii Nakryiko * 1. Strings deduplication. 2877d5caef5bSAndrii Nakryiko * 2. Primitive types deduplication (int, enum, fwd). 2878d5caef5bSAndrii Nakryiko * 3. Struct/union types deduplication. 2879d5caef5bSAndrii Nakryiko * 4. Reference types deduplication (pointers, typedefs, arrays, funcs, func 2880d5caef5bSAndrii Nakryiko * protos, and const/volatile/restrict modifiers). 2881d5caef5bSAndrii Nakryiko * 5. Types compaction. 2882d5caef5bSAndrii Nakryiko * 6. Types remapping. 2883d5caef5bSAndrii Nakryiko * 2884d5caef5bSAndrii Nakryiko * Algorithm determines canonical type descriptor, which is a single 2885d5caef5bSAndrii Nakryiko * representative type for each truly unique type. This canonical type is the 2886d5caef5bSAndrii Nakryiko * one that will go into final deduplicated BTF type information. For 2887d5caef5bSAndrii Nakryiko * struct/unions, it is also the type that algorithm will merge additional type 2888d5caef5bSAndrii Nakryiko * information into (while resolving FWDs), as it discovers it from data in 2889d5caef5bSAndrii Nakryiko * other CUs. Each input BTF type eventually gets either mapped to itself, if 2890d5caef5bSAndrii Nakryiko * that type is canonical, or to some other type, if that type is equivalent 2891d5caef5bSAndrii Nakryiko * and was chosen as canonical representative. This mapping is stored in 2892d5caef5bSAndrii Nakryiko * `btf_dedup->map` array. This map is also used to record STRUCT/UNION that 2893d5caef5bSAndrii Nakryiko * FWD type got resolved to. 2894d5caef5bSAndrii Nakryiko * 2895d5caef5bSAndrii Nakryiko * To facilitate fast discovery of canonical types, we also maintain canonical 2896d5caef5bSAndrii Nakryiko * index (`btf_dedup->dedup_table`), which maps type descriptor's signature hash 2897d5caef5bSAndrii Nakryiko * (i.e., hashed kind, name, size, fields, etc) into a list of canonical types 2898d5caef5bSAndrii Nakryiko * that match that signature. With sufficiently good choice of type signature 2899d5caef5bSAndrii Nakryiko * hashing function, we can limit number of canonical types for each unique type 2900d5caef5bSAndrii Nakryiko * signature to a very small number, allowing to find canonical type for any 2901d5caef5bSAndrii Nakryiko * duplicated type very quickly. 2902d5caef5bSAndrii Nakryiko * 2903d5caef5bSAndrii Nakryiko * Struct/union deduplication is the most critical part and algorithm for 2904d5caef5bSAndrii Nakryiko * deduplicating structs/unions is described in greater details in comments for 2905d5caef5bSAndrii Nakryiko * `btf_dedup_is_equiv` function. 2906d5caef5bSAndrii Nakryiko */ 2907d5caef5bSAndrii Nakryiko int btf__dedup(struct btf *btf, struct btf_ext *btf_ext, 2908d5caef5bSAndrii Nakryiko const struct btf_dedup_opts *opts) 2909d5caef5bSAndrii Nakryiko { 2910d5caef5bSAndrii Nakryiko struct btf_dedup *d = btf_dedup_new(btf, btf_ext, opts); 2911d5caef5bSAndrii Nakryiko int err; 2912d5caef5bSAndrii Nakryiko 2913d5caef5bSAndrii Nakryiko if (IS_ERR(d)) { 2914d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_new failed: %ld", PTR_ERR(d)); 2915e9fc3ce9SAndrii Nakryiko return libbpf_err(-EINVAL); 2916d5caef5bSAndrii Nakryiko } 2917d5caef5bSAndrii Nakryiko 2918919d2b1dSAndrii Nakryiko if (btf_ensure_modifiable(btf)) 2919e9fc3ce9SAndrii Nakryiko return libbpf_err(-ENOMEM); 2920919d2b1dSAndrii Nakryiko 2921f86524efSAndrii Nakryiko err = btf_dedup_prep(d); 2922f86524efSAndrii Nakryiko if (err) { 2923f86524efSAndrii Nakryiko pr_debug("btf_dedup_prep failed:%d\n", err); 2924f86524efSAndrii Nakryiko goto done; 2925f86524efSAndrii Nakryiko } 2926d5caef5bSAndrii Nakryiko err = btf_dedup_strings(d); 2927d5caef5bSAndrii Nakryiko if (err < 0) { 2928d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_strings failed:%d\n", err); 2929d5caef5bSAndrii Nakryiko goto done; 2930d5caef5bSAndrii Nakryiko } 2931d5caef5bSAndrii Nakryiko err = btf_dedup_prim_types(d); 2932d5caef5bSAndrii Nakryiko if (err < 0) { 2933d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_prim_types failed:%d\n", err); 2934d5caef5bSAndrii Nakryiko goto done; 2935d5caef5bSAndrii Nakryiko } 2936d5caef5bSAndrii Nakryiko err = btf_dedup_struct_types(d); 2937d5caef5bSAndrii Nakryiko if (err < 0) { 2938d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_struct_types failed:%d\n", err); 2939d5caef5bSAndrii Nakryiko goto done; 2940d5caef5bSAndrii Nakryiko } 2941d5caef5bSAndrii Nakryiko err = btf_dedup_ref_types(d); 2942d5caef5bSAndrii Nakryiko if (err < 0) { 2943d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_ref_types failed:%d\n", err); 2944d5caef5bSAndrii Nakryiko goto done; 2945d5caef5bSAndrii Nakryiko } 2946d5caef5bSAndrii Nakryiko err = btf_dedup_compact_types(d); 2947d5caef5bSAndrii Nakryiko if (err < 0) { 2948d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_compact_types failed:%d\n", err); 2949d5caef5bSAndrii Nakryiko goto done; 2950d5caef5bSAndrii Nakryiko } 2951d5caef5bSAndrii Nakryiko err = btf_dedup_remap_types(d); 2952d5caef5bSAndrii Nakryiko if (err < 0) { 2953d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_remap_types failed:%d\n", err); 2954d5caef5bSAndrii Nakryiko goto done; 2955d5caef5bSAndrii Nakryiko } 2956d5caef5bSAndrii Nakryiko 2957d5caef5bSAndrii Nakryiko done: 2958d5caef5bSAndrii Nakryiko btf_dedup_free(d); 2959e9fc3ce9SAndrii Nakryiko return libbpf_err(err); 2960d5caef5bSAndrii Nakryiko } 2961d5caef5bSAndrii Nakryiko 2962d5caef5bSAndrii Nakryiko #define BTF_UNPROCESSED_ID ((__u32)-1) 2963d5caef5bSAndrii Nakryiko #define BTF_IN_PROGRESS_ID ((__u32)-2) 2964d5caef5bSAndrii Nakryiko 2965d5caef5bSAndrii Nakryiko struct btf_dedup { 2966d5caef5bSAndrii Nakryiko /* .BTF section to be deduped in-place */ 2967d5caef5bSAndrii Nakryiko struct btf *btf; 2968d5caef5bSAndrii Nakryiko /* 2969d5caef5bSAndrii Nakryiko * Optional .BTF.ext section. When provided, any strings referenced 2970d5caef5bSAndrii Nakryiko * from it will be taken into account when deduping strings 2971d5caef5bSAndrii Nakryiko */ 2972d5caef5bSAndrii Nakryiko struct btf_ext *btf_ext; 2973d5caef5bSAndrii Nakryiko /* 2974d5caef5bSAndrii Nakryiko * This is a map from any type's signature hash to a list of possible 2975d5caef5bSAndrii Nakryiko * canonical representative type candidates. Hash collisions are 2976d5caef5bSAndrii Nakryiko * ignored, so even types of various kinds can share same list of 2977d5caef5bSAndrii Nakryiko * candidates, which is fine because we rely on subsequent 2978d5caef5bSAndrii Nakryiko * btf_xxx_equal() checks to authoritatively verify type equality. 2979d5caef5bSAndrii Nakryiko */ 29802fc3fc0bSAndrii Nakryiko struct hashmap *dedup_table; 2981d5caef5bSAndrii Nakryiko /* Canonical types map */ 2982d5caef5bSAndrii Nakryiko __u32 *map; 2983d5caef5bSAndrii Nakryiko /* Hypothetical mapping, used during type graph equivalence checks */ 2984d5caef5bSAndrii Nakryiko __u32 *hypot_map; 2985d5caef5bSAndrii Nakryiko __u32 *hypot_list; 2986d5caef5bSAndrii Nakryiko size_t hypot_cnt; 2987d5caef5bSAndrii Nakryiko size_t hypot_cap; 2988f86524efSAndrii Nakryiko /* Whether hypothetical mapping, if successful, would need to adjust 2989f86524efSAndrii Nakryiko * already canonicalized types (due to a new forward declaration to 2990f86524efSAndrii Nakryiko * concrete type resolution). In such case, during split BTF dedup 2991f86524efSAndrii Nakryiko * candidate type would still be considered as different, because base 2992f86524efSAndrii Nakryiko * BTF is considered to be immutable. 2993f86524efSAndrii Nakryiko */ 2994f86524efSAndrii Nakryiko bool hypot_adjust_canon; 2995d5caef5bSAndrii Nakryiko /* Various option modifying behavior of algorithm */ 2996d5caef5bSAndrii Nakryiko struct btf_dedup_opts opts; 299788a82c2aSAndrii Nakryiko /* temporary strings deduplication state */ 299890d76d3eSAndrii Nakryiko struct strset *strs_set; 2999d5caef5bSAndrii Nakryiko }; 3000d5caef5bSAndrii Nakryiko 30012fc3fc0bSAndrii Nakryiko static long hash_combine(long h, long value) 3002d5caef5bSAndrii Nakryiko { 30032fc3fc0bSAndrii Nakryiko return h * 31 + value; 3004d5caef5bSAndrii Nakryiko } 3005d5caef5bSAndrii Nakryiko 30062fc3fc0bSAndrii Nakryiko #define for_each_dedup_cand(d, node, hash) \ 30072fc3fc0bSAndrii Nakryiko hashmap__for_each_key_entry(d->dedup_table, node, (void *)hash) 3008d5caef5bSAndrii Nakryiko 30092fc3fc0bSAndrii Nakryiko static int btf_dedup_table_add(struct btf_dedup *d, long hash, __u32 type_id) 3010d5caef5bSAndrii Nakryiko { 30112fc3fc0bSAndrii Nakryiko return hashmap__append(d->dedup_table, 30122fc3fc0bSAndrii Nakryiko (void *)hash, (void *)(long)type_id); 3013d5caef5bSAndrii Nakryiko } 3014d5caef5bSAndrii Nakryiko 3015d5caef5bSAndrii Nakryiko static int btf_dedup_hypot_map_add(struct btf_dedup *d, 3016d5caef5bSAndrii Nakryiko __u32 from_id, __u32 to_id) 3017d5caef5bSAndrii Nakryiko { 3018d5caef5bSAndrii Nakryiko if (d->hypot_cnt == d->hypot_cap) { 3019d5caef5bSAndrii Nakryiko __u32 *new_list; 3020d5caef5bSAndrii Nakryiko 3021fb2426adSMartin KaFai Lau d->hypot_cap += max((size_t)16, d->hypot_cap / 2); 3022029258d7SAndrii Nakryiko new_list = libbpf_reallocarray(d->hypot_list, d->hypot_cap, sizeof(__u32)); 3023d5caef5bSAndrii Nakryiko if (!new_list) 3024d5caef5bSAndrii Nakryiko return -ENOMEM; 3025d5caef5bSAndrii Nakryiko d->hypot_list = new_list; 3026d5caef5bSAndrii Nakryiko } 3027d5caef5bSAndrii Nakryiko d->hypot_list[d->hypot_cnt++] = from_id; 3028d5caef5bSAndrii Nakryiko d->hypot_map[from_id] = to_id; 3029d5caef5bSAndrii Nakryiko return 0; 3030d5caef5bSAndrii Nakryiko } 3031d5caef5bSAndrii Nakryiko 3032d5caef5bSAndrii Nakryiko static void btf_dedup_clear_hypot_map(struct btf_dedup *d) 3033d5caef5bSAndrii Nakryiko { 3034d5caef5bSAndrii Nakryiko int i; 3035d5caef5bSAndrii Nakryiko 3036d5caef5bSAndrii Nakryiko for (i = 0; i < d->hypot_cnt; i++) 3037d5caef5bSAndrii Nakryiko d->hypot_map[d->hypot_list[i]] = BTF_UNPROCESSED_ID; 3038d5caef5bSAndrii Nakryiko d->hypot_cnt = 0; 3039f86524efSAndrii Nakryiko d->hypot_adjust_canon = false; 3040d5caef5bSAndrii Nakryiko } 3041d5caef5bSAndrii Nakryiko 3042d5caef5bSAndrii Nakryiko static void btf_dedup_free(struct btf_dedup *d) 3043d5caef5bSAndrii Nakryiko { 30442fc3fc0bSAndrii Nakryiko hashmap__free(d->dedup_table); 30452fc3fc0bSAndrii Nakryiko d->dedup_table = NULL; 3046d5caef5bSAndrii Nakryiko 3047d5caef5bSAndrii Nakryiko free(d->map); 3048d5caef5bSAndrii Nakryiko d->map = NULL; 3049d5caef5bSAndrii Nakryiko 3050d5caef5bSAndrii Nakryiko free(d->hypot_map); 3051d5caef5bSAndrii Nakryiko d->hypot_map = NULL; 3052d5caef5bSAndrii Nakryiko 3053d5caef5bSAndrii Nakryiko free(d->hypot_list); 3054d5caef5bSAndrii Nakryiko d->hypot_list = NULL; 3055d5caef5bSAndrii Nakryiko 3056d5caef5bSAndrii Nakryiko free(d); 3057d5caef5bSAndrii Nakryiko } 3058d5caef5bSAndrii Nakryiko 30592fc3fc0bSAndrii Nakryiko static size_t btf_dedup_identity_hash_fn(const void *key, void *ctx) 306051edf5f6SAndrii Nakryiko { 30612fc3fc0bSAndrii Nakryiko return (size_t)key; 306251edf5f6SAndrii Nakryiko } 306351edf5f6SAndrii Nakryiko 30642fc3fc0bSAndrii Nakryiko static size_t btf_dedup_collision_hash_fn(const void *key, void *ctx) 30652fc3fc0bSAndrii Nakryiko { 30662fc3fc0bSAndrii Nakryiko return 0; 30672fc3fc0bSAndrii Nakryiko } 30682fc3fc0bSAndrii Nakryiko 30692fc3fc0bSAndrii Nakryiko static bool btf_dedup_equal_fn(const void *k1, const void *k2, void *ctx) 30702fc3fc0bSAndrii Nakryiko { 30712fc3fc0bSAndrii Nakryiko return k1 == k2; 30722fc3fc0bSAndrii Nakryiko } 307351edf5f6SAndrii Nakryiko 3074d5caef5bSAndrii Nakryiko static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext, 3075d5caef5bSAndrii Nakryiko const struct btf_dedup_opts *opts) 3076d5caef5bSAndrii Nakryiko { 3077d5caef5bSAndrii Nakryiko struct btf_dedup *d = calloc(1, sizeof(struct btf_dedup)); 30782fc3fc0bSAndrii Nakryiko hashmap_hash_fn hash_fn = btf_dedup_identity_hash_fn; 3079f86524efSAndrii Nakryiko int i, err = 0, type_cnt; 3080d5caef5bSAndrii Nakryiko 3081d5caef5bSAndrii Nakryiko if (!d) 3082d5caef5bSAndrii Nakryiko return ERR_PTR(-ENOMEM); 3083d5caef5bSAndrii Nakryiko 308451edf5f6SAndrii Nakryiko d->opts.dont_resolve_fwds = opts && opts->dont_resolve_fwds; 30852fc3fc0bSAndrii Nakryiko /* dedup_table_size is now used only to force collisions in tests */ 30862fc3fc0bSAndrii Nakryiko if (opts && opts->dedup_table_size == 1) 30872fc3fc0bSAndrii Nakryiko hash_fn = btf_dedup_collision_hash_fn; 308851edf5f6SAndrii Nakryiko 3089d5caef5bSAndrii Nakryiko d->btf = btf; 3090d5caef5bSAndrii Nakryiko d->btf_ext = btf_ext; 3091d5caef5bSAndrii Nakryiko 30922fc3fc0bSAndrii Nakryiko d->dedup_table = hashmap__new(hash_fn, btf_dedup_equal_fn, NULL); 30932fc3fc0bSAndrii Nakryiko if (IS_ERR(d->dedup_table)) { 30942fc3fc0bSAndrii Nakryiko err = PTR_ERR(d->dedup_table); 30952fc3fc0bSAndrii Nakryiko d->dedup_table = NULL; 3096d5caef5bSAndrii Nakryiko goto done; 3097d5caef5bSAndrii Nakryiko } 3098d5caef5bSAndrii Nakryiko 3099f86524efSAndrii Nakryiko type_cnt = btf__get_nr_types(btf) + 1; 3100f86524efSAndrii Nakryiko d->map = malloc(sizeof(__u32) * type_cnt); 3101d5caef5bSAndrii Nakryiko if (!d->map) { 3102d5caef5bSAndrii Nakryiko err = -ENOMEM; 3103d5caef5bSAndrii Nakryiko goto done; 3104d5caef5bSAndrii Nakryiko } 3105d5caef5bSAndrii Nakryiko /* special BTF "void" type is made canonical immediately */ 3106d5caef5bSAndrii Nakryiko d->map[0] = 0; 3107f86524efSAndrii Nakryiko for (i = 1; i < type_cnt; i++) { 3108740e69c3SAndrii Nakryiko struct btf_type *t = btf_type_by_id(d->btf, i); 3109189cf5a4SAndrii Nakryiko 3110189cf5a4SAndrii Nakryiko /* VAR and DATASEC are never deduped and are self-canonical */ 3111b03bc685SAndrii Nakryiko if (btf_is_var(t) || btf_is_datasec(t)) 3112189cf5a4SAndrii Nakryiko d->map[i] = i; 3113189cf5a4SAndrii Nakryiko else 3114d5caef5bSAndrii Nakryiko d->map[i] = BTF_UNPROCESSED_ID; 3115189cf5a4SAndrii Nakryiko } 3116d5caef5bSAndrii Nakryiko 3117f86524efSAndrii Nakryiko d->hypot_map = malloc(sizeof(__u32) * type_cnt); 3118d5caef5bSAndrii Nakryiko if (!d->hypot_map) { 3119d5caef5bSAndrii Nakryiko err = -ENOMEM; 3120d5caef5bSAndrii Nakryiko goto done; 3121d5caef5bSAndrii Nakryiko } 3122f86524efSAndrii Nakryiko for (i = 0; i < type_cnt; i++) 3123d5caef5bSAndrii Nakryiko d->hypot_map[i] = BTF_UNPROCESSED_ID; 3124d5caef5bSAndrii Nakryiko 3125d5caef5bSAndrii Nakryiko done: 3126d5caef5bSAndrii Nakryiko if (err) { 3127d5caef5bSAndrii Nakryiko btf_dedup_free(d); 3128d5caef5bSAndrii Nakryiko return ERR_PTR(err); 3129d5caef5bSAndrii Nakryiko } 3130d5caef5bSAndrii Nakryiko 3131d5caef5bSAndrii Nakryiko return d; 3132d5caef5bSAndrii Nakryiko } 3133d5caef5bSAndrii Nakryiko 3134d5caef5bSAndrii Nakryiko /* 3135d5caef5bSAndrii Nakryiko * Iterate over all possible places in .BTF and .BTF.ext that can reference 3136d5caef5bSAndrii Nakryiko * string and pass pointer to it to a provided callback `fn`. 3137d5caef5bSAndrii Nakryiko */ 3138f36e99a4SAndrii Nakryiko static int btf_for_each_str_off(struct btf_dedup *d, str_off_visit_fn fn, void *ctx) 3139d5caef5bSAndrii Nakryiko { 3140f36e99a4SAndrii Nakryiko int i, r; 3141d5caef5bSAndrii Nakryiko 3142f86524efSAndrii Nakryiko for (i = 0; i < d->btf->nr_types; i++) { 3143f36e99a4SAndrii Nakryiko struct btf_type *t = btf_type_by_id(d->btf, d->btf->start_id + i); 3144f36e99a4SAndrii Nakryiko 3145f36e99a4SAndrii Nakryiko r = btf_type_visit_str_offs(t, fn, ctx); 3146d5caef5bSAndrii Nakryiko if (r) 3147d5caef5bSAndrii Nakryiko return r; 3148d5caef5bSAndrii Nakryiko } 3149d5caef5bSAndrii Nakryiko 3150d5caef5bSAndrii Nakryiko if (!d->btf_ext) 3151d5caef5bSAndrii Nakryiko return 0; 3152d5caef5bSAndrii Nakryiko 3153f36e99a4SAndrii Nakryiko r = btf_ext_visit_str_offs(d->btf_ext, fn, ctx); 3154d5caef5bSAndrii Nakryiko if (r) 3155d5caef5bSAndrii Nakryiko return r; 3156d5caef5bSAndrii Nakryiko 3157d5caef5bSAndrii Nakryiko return 0; 3158d5caef5bSAndrii Nakryiko } 3159d5caef5bSAndrii Nakryiko 316088a82c2aSAndrii Nakryiko static int strs_dedup_remap_str_off(__u32 *str_off_ptr, void *ctx) 3161d5caef5bSAndrii Nakryiko { 316288a82c2aSAndrii Nakryiko struct btf_dedup *d = ctx; 3163f86524efSAndrii Nakryiko __u32 str_off = *str_off_ptr; 316488a82c2aSAndrii Nakryiko const char *s; 316590d76d3eSAndrii Nakryiko int off, err; 3166d5caef5bSAndrii Nakryiko 3167f86524efSAndrii Nakryiko /* don't touch empty string or string in main BTF */ 3168f86524efSAndrii Nakryiko if (str_off == 0 || str_off < d->btf->start_str_off) 3169d5caef5bSAndrii Nakryiko return 0; 3170d5caef5bSAndrii Nakryiko 3171f86524efSAndrii Nakryiko s = btf__str_by_offset(d->btf, str_off); 3172f86524efSAndrii Nakryiko if (d->btf->base_btf) { 3173f86524efSAndrii Nakryiko err = btf__find_str(d->btf->base_btf, s); 3174f86524efSAndrii Nakryiko if (err >= 0) { 3175f86524efSAndrii Nakryiko *str_off_ptr = err; 3176f86524efSAndrii Nakryiko return 0; 3177f86524efSAndrii Nakryiko } 3178f86524efSAndrii Nakryiko if (err != -ENOENT) 3179f86524efSAndrii Nakryiko return err; 3180f86524efSAndrii Nakryiko } 3181f86524efSAndrii Nakryiko 318290d76d3eSAndrii Nakryiko off = strset__add_str(d->strs_set, s); 318390d76d3eSAndrii Nakryiko if (off < 0) 318490d76d3eSAndrii Nakryiko return off; 318588a82c2aSAndrii Nakryiko 318690d76d3eSAndrii Nakryiko *str_off_ptr = d->btf->start_str_off + off; 3187d5caef5bSAndrii Nakryiko return 0; 3188d5caef5bSAndrii Nakryiko } 3189d5caef5bSAndrii Nakryiko 3190d5caef5bSAndrii Nakryiko /* 3191d5caef5bSAndrii Nakryiko * Dedup string and filter out those that are not referenced from either .BTF 3192d5caef5bSAndrii Nakryiko * or .BTF.ext (if provided) sections. 3193d5caef5bSAndrii Nakryiko * 3194d5caef5bSAndrii Nakryiko * This is done by building index of all strings in BTF's string section, 3195d5caef5bSAndrii Nakryiko * then iterating over all entities that can reference strings (e.g., type 3196d5caef5bSAndrii Nakryiko * names, struct field names, .BTF.ext line info, etc) and marking corresponding 3197d5caef5bSAndrii Nakryiko * strings as used. After that all used strings are deduped and compacted into 3198d5caef5bSAndrii Nakryiko * sequential blob of memory and new offsets are calculated. Then all the string 3199d5caef5bSAndrii Nakryiko * references are iterated again and rewritten using new offsets. 3200d5caef5bSAndrii Nakryiko */ 3201d5caef5bSAndrii Nakryiko static int btf_dedup_strings(struct btf_dedup *d) 3202d5caef5bSAndrii Nakryiko { 320388a82c2aSAndrii Nakryiko int err; 3204d5caef5bSAndrii Nakryiko 3205919d2b1dSAndrii Nakryiko if (d->btf->strs_deduped) 3206919d2b1dSAndrii Nakryiko return 0; 3207919d2b1dSAndrii Nakryiko 320890d76d3eSAndrii Nakryiko d->strs_set = strset__new(BTF_MAX_STR_OFFSET, NULL, 0); 320990d76d3eSAndrii Nakryiko if (IS_ERR(d->strs_set)) { 321090d76d3eSAndrii Nakryiko err = PTR_ERR(d->strs_set); 321188a82c2aSAndrii Nakryiko goto err_out; 3212d5caef5bSAndrii Nakryiko } 3213d5caef5bSAndrii Nakryiko 3214f86524efSAndrii Nakryiko if (!d->btf->base_btf) { 321588a82c2aSAndrii Nakryiko /* insert empty string; we won't be looking it up during strings 321688a82c2aSAndrii Nakryiko * dedup, but it's good to have it for generic BTF string lookups 321788a82c2aSAndrii Nakryiko */ 321890d76d3eSAndrii Nakryiko err = strset__add_str(d->strs_set, ""); 321990d76d3eSAndrii Nakryiko if (err < 0) 322088a82c2aSAndrii Nakryiko goto err_out; 3221f86524efSAndrii Nakryiko } 3222d5caef5bSAndrii Nakryiko 3223d5caef5bSAndrii Nakryiko /* remap string offsets */ 322488a82c2aSAndrii Nakryiko err = btf_for_each_str_off(d, strs_dedup_remap_str_off, d); 3225d5caef5bSAndrii Nakryiko if (err) 322688a82c2aSAndrii Nakryiko goto err_out; 3227d5caef5bSAndrii Nakryiko 322888a82c2aSAndrii Nakryiko /* replace BTF string data and hash with deduped ones */ 322990d76d3eSAndrii Nakryiko strset__free(d->btf->strs_set); 323090d76d3eSAndrii Nakryiko d->btf->hdr->str_len = strset__data_size(d->strs_set); 323190d76d3eSAndrii Nakryiko d->btf->strs_set = d->strs_set; 323290d76d3eSAndrii Nakryiko d->strs_set = NULL; 3233919d2b1dSAndrii Nakryiko d->btf->strs_deduped = true; 323488a82c2aSAndrii Nakryiko return 0; 3235d5caef5bSAndrii Nakryiko 323688a82c2aSAndrii Nakryiko err_out: 323790d76d3eSAndrii Nakryiko strset__free(d->strs_set); 323890d76d3eSAndrii Nakryiko d->strs_set = NULL; 323988a82c2aSAndrii Nakryiko 3240d5caef5bSAndrii Nakryiko return err; 3241d5caef5bSAndrii Nakryiko } 3242d5caef5bSAndrii Nakryiko 32432fc3fc0bSAndrii Nakryiko static long btf_hash_common(struct btf_type *t) 3244d5caef5bSAndrii Nakryiko { 32452fc3fc0bSAndrii Nakryiko long h; 3246d5caef5bSAndrii Nakryiko 3247d5caef5bSAndrii Nakryiko h = hash_combine(0, t->name_off); 3248d5caef5bSAndrii Nakryiko h = hash_combine(h, t->info); 3249d5caef5bSAndrii Nakryiko h = hash_combine(h, t->size); 3250d5caef5bSAndrii Nakryiko return h; 3251d5caef5bSAndrii Nakryiko } 3252d5caef5bSAndrii Nakryiko 3253d5caef5bSAndrii Nakryiko static bool btf_equal_common(struct btf_type *t1, struct btf_type *t2) 3254d5caef5bSAndrii Nakryiko { 3255d5caef5bSAndrii Nakryiko return t1->name_off == t2->name_off && 3256d5caef5bSAndrii Nakryiko t1->info == t2->info && 3257d5caef5bSAndrii Nakryiko t1->size == t2->size; 3258d5caef5bSAndrii Nakryiko } 3259d5caef5bSAndrii Nakryiko 3260d5caef5bSAndrii Nakryiko /* Calculate type signature hash of INT. */ 32612fc3fc0bSAndrii Nakryiko static long btf_hash_int(struct btf_type *t) 3262d5caef5bSAndrii Nakryiko { 3263d5caef5bSAndrii Nakryiko __u32 info = *(__u32 *)(t + 1); 32642fc3fc0bSAndrii Nakryiko long h; 3265d5caef5bSAndrii Nakryiko 3266d5caef5bSAndrii Nakryiko h = btf_hash_common(t); 3267d5caef5bSAndrii Nakryiko h = hash_combine(h, info); 3268d5caef5bSAndrii Nakryiko return h; 3269d5caef5bSAndrii Nakryiko } 3270d5caef5bSAndrii Nakryiko 3271d5caef5bSAndrii Nakryiko /* Check structural equality of two INTs. */ 3272d5caef5bSAndrii Nakryiko static bool btf_equal_int(struct btf_type *t1, struct btf_type *t2) 3273d5caef5bSAndrii Nakryiko { 3274d5caef5bSAndrii Nakryiko __u32 info1, info2; 3275d5caef5bSAndrii Nakryiko 3276d5caef5bSAndrii Nakryiko if (!btf_equal_common(t1, t2)) 3277d5caef5bSAndrii Nakryiko return false; 3278d5caef5bSAndrii Nakryiko info1 = *(__u32 *)(t1 + 1); 3279d5caef5bSAndrii Nakryiko info2 = *(__u32 *)(t2 + 1); 3280d5caef5bSAndrii Nakryiko return info1 == info2; 3281d5caef5bSAndrii Nakryiko } 3282d5caef5bSAndrii Nakryiko 3283d5caef5bSAndrii Nakryiko /* Calculate type signature hash of ENUM. */ 32842fc3fc0bSAndrii Nakryiko static long btf_hash_enum(struct btf_type *t) 3285d5caef5bSAndrii Nakryiko { 32862fc3fc0bSAndrii Nakryiko long h; 3287d5caef5bSAndrii Nakryiko 32889768095bSAndrii Nakryiko /* don't hash vlen and enum members to support enum fwd resolving */ 32899768095bSAndrii Nakryiko h = hash_combine(0, t->name_off); 32909768095bSAndrii Nakryiko h = hash_combine(h, t->info & ~0xffff); 32919768095bSAndrii Nakryiko h = hash_combine(h, t->size); 3292d5caef5bSAndrii Nakryiko return h; 3293d5caef5bSAndrii Nakryiko } 3294d5caef5bSAndrii Nakryiko 3295d5caef5bSAndrii Nakryiko /* Check structural equality of two ENUMs. */ 3296d5caef5bSAndrii Nakryiko static bool btf_equal_enum(struct btf_type *t1, struct btf_type *t2) 3297d5caef5bSAndrii Nakryiko { 3298b03bc685SAndrii Nakryiko const struct btf_enum *m1, *m2; 3299d5caef5bSAndrii Nakryiko __u16 vlen; 3300d5caef5bSAndrii Nakryiko int i; 3301d5caef5bSAndrii Nakryiko 3302d5caef5bSAndrii Nakryiko if (!btf_equal_common(t1, t2)) 3303d5caef5bSAndrii Nakryiko return false; 3304d5caef5bSAndrii Nakryiko 3305b03bc685SAndrii Nakryiko vlen = btf_vlen(t1); 3306b03bc685SAndrii Nakryiko m1 = btf_enum(t1); 3307b03bc685SAndrii Nakryiko m2 = btf_enum(t2); 3308d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3309d5caef5bSAndrii Nakryiko if (m1->name_off != m2->name_off || m1->val != m2->val) 3310d5caef5bSAndrii Nakryiko return false; 3311d5caef5bSAndrii Nakryiko m1++; 3312d5caef5bSAndrii Nakryiko m2++; 3313d5caef5bSAndrii Nakryiko } 3314d5caef5bSAndrii Nakryiko return true; 3315d5caef5bSAndrii Nakryiko } 3316d5caef5bSAndrii Nakryiko 33179768095bSAndrii Nakryiko static inline bool btf_is_enum_fwd(struct btf_type *t) 33189768095bSAndrii Nakryiko { 3319b03bc685SAndrii Nakryiko return btf_is_enum(t) && btf_vlen(t) == 0; 33209768095bSAndrii Nakryiko } 33219768095bSAndrii Nakryiko 33229768095bSAndrii Nakryiko static bool btf_compat_enum(struct btf_type *t1, struct btf_type *t2) 33239768095bSAndrii Nakryiko { 33249768095bSAndrii Nakryiko if (!btf_is_enum_fwd(t1) && !btf_is_enum_fwd(t2)) 33259768095bSAndrii Nakryiko return btf_equal_enum(t1, t2); 33269768095bSAndrii Nakryiko /* ignore vlen when comparing */ 33279768095bSAndrii Nakryiko return t1->name_off == t2->name_off && 33289768095bSAndrii Nakryiko (t1->info & ~0xffff) == (t2->info & ~0xffff) && 33299768095bSAndrii Nakryiko t1->size == t2->size; 33309768095bSAndrii Nakryiko } 33319768095bSAndrii Nakryiko 3332d5caef5bSAndrii Nakryiko /* 3333d5caef5bSAndrii Nakryiko * Calculate type signature hash of STRUCT/UNION, ignoring referenced type IDs, 3334d5caef5bSAndrii Nakryiko * as referenced type IDs equivalence is established separately during type 3335d5caef5bSAndrii Nakryiko * graph equivalence check algorithm. 3336d5caef5bSAndrii Nakryiko */ 33372fc3fc0bSAndrii Nakryiko static long btf_hash_struct(struct btf_type *t) 3338d5caef5bSAndrii Nakryiko { 3339b03bc685SAndrii Nakryiko const struct btf_member *member = btf_members(t); 3340b03bc685SAndrii Nakryiko __u32 vlen = btf_vlen(t); 33412fc3fc0bSAndrii Nakryiko long h = btf_hash_common(t); 3342d5caef5bSAndrii Nakryiko int i; 3343d5caef5bSAndrii Nakryiko 3344d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3345d5caef5bSAndrii Nakryiko h = hash_combine(h, member->name_off); 3346d5caef5bSAndrii Nakryiko h = hash_combine(h, member->offset); 3347d5caef5bSAndrii Nakryiko /* no hashing of referenced type ID, it can be unresolved yet */ 3348d5caef5bSAndrii Nakryiko member++; 3349d5caef5bSAndrii Nakryiko } 3350d5caef5bSAndrii Nakryiko return h; 3351d5caef5bSAndrii Nakryiko } 3352d5caef5bSAndrii Nakryiko 3353d5caef5bSAndrii Nakryiko /* 3354d5caef5bSAndrii Nakryiko * Check structural compatibility of two FUNC_PROTOs, ignoring referenced type 3355d5caef5bSAndrii Nakryiko * IDs. This check is performed during type graph equivalence check and 3356d5caef5bSAndrii Nakryiko * referenced types equivalence is checked separately. 3357d5caef5bSAndrii Nakryiko */ 335891097fbeSAndrii Nakryiko static bool btf_shallow_equal_struct(struct btf_type *t1, struct btf_type *t2) 3359d5caef5bSAndrii Nakryiko { 3360b03bc685SAndrii Nakryiko const struct btf_member *m1, *m2; 3361d5caef5bSAndrii Nakryiko __u16 vlen; 3362d5caef5bSAndrii Nakryiko int i; 3363d5caef5bSAndrii Nakryiko 3364d5caef5bSAndrii Nakryiko if (!btf_equal_common(t1, t2)) 3365d5caef5bSAndrii Nakryiko return false; 3366d5caef5bSAndrii Nakryiko 3367b03bc685SAndrii Nakryiko vlen = btf_vlen(t1); 3368b03bc685SAndrii Nakryiko m1 = btf_members(t1); 3369b03bc685SAndrii Nakryiko m2 = btf_members(t2); 3370d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3371d5caef5bSAndrii Nakryiko if (m1->name_off != m2->name_off || m1->offset != m2->offset) 3372d5caef5bSAndrii Nakryiko return false; 3373d5caef5bSAndrii Nakryiko m1++; 3374d5caef5bSAndrii Nakryiko m2++; 3375d5caef5bSAndrii Nakryiko } 3376d5caef5bSAndrii Nakryiko return true; 3377d5caef5bSAndrii Nakryiko } 3378d5caef5bSAndrii Nakryiko 3379d5caef5bSAndrii Nakryiko /* 3380d5caef5bSAndrii Nakryiko * Calculate type signature hash of ARRAY, including referenced type IDs, 3381d5caef5bSAndrii Nakryiko * under assumption that they were already resolved to canonical type IDs and 3382d5caef5bSAndrii Nakryiko * are not going to change. 3383d5caef5bSAndrii Nakryiko */ 33842fc3fc0bSAndrii Nakryiko static long btf_hash_array(struct btf_type *t) 3385d5caef5bSAndrii Nakryiko { 3386b03bc685SAndrii Nakryiko const struct btf_array *info = btf_array(t); 33872fc3fc0bSAndrii Nakryiko long h = btf_hash_common(t); 3388d5caef5bSAndrii Nakryiko 3389d5caef5bSAndrii Nakryiko h = hash_combine(h, info->type); 3390d5caef5bSAndrii Nakryiko h = hash_combine(h, info->index_type); 3391d5caef5bSAndrii Nakryiko h = hash_combine(h, info->nelems); 3392d5caef5bSAndrii Nakryiko return h; 3393d5caef5bSAndrii Nakryiko } 3394d5caef5bSAndrii Nakryiko 3395d5caef5bSAndrii Nakryiko /* 3396d5caef5bSAndrii Nakryiko * Check exact equality of two ARRAYs, taking into account referenced 3397d5caef5bSAndrii Nakryiko * type IDs, under assumption that they were already resolved to canonical 3398d5caef5bSAndrii Nakryiko * type IDs and are not going to change. 3399d5caef5bSAndrii Nakryiko * This function is called during reference types deduplication to compare 3400d5caef5bSAndrii Nakryiko * ARRAY to potential canonical representative. 3401d5caef5bSAndrii Nakryiko */ 3402d5caef5bSAndrii Nakryiko static bool btf_equal_array(struct btf_type *t1, struct btf_type *t2) 3403d5caef5bSAndrii Nakryiko { 3404b03bc685SAndrii Nakryiko const struct btf_array *info1, *info2; 3405d5caef5bSAndrii Nakryiko 3406d5caef5bSAndrii Nakryiko if (!btf_equal_common(t1, t2)) 3407d5caef5bSAndrii Nakryiko return false; 3408d5caef5bSAndrii Nakryiko 3409b03bc685SAndrii Nakryiko info1 = btf_array(t1); 3410b03bc685SAndrii Nakryiko info2 = btf_array(t2); 3411d5caef5bSAndrii Nakryiko return info1->type == info2->type && 3412d5caef5bSAndrii Nakryiko info1->index_type == info2->index_type && 3413d5caef5bSAndrii Nakryiko info1->nelems == info2->nelems; 3414d5caef5bSAndrii Nakryiko } 3415d5caef5bSAndrii Nakryiko 3416d5caef5bSAndrii Nakryiko /* 3417d5caef5bSAndrii Nakryiko * Check structural compatibility of two ARRAYs, ignoring referenced type 3418d5caef5bSAndrii Nakryiko * IDs. This check is performed during type graph equivalence check and 3419d5caef5bSAndrii Nakryiko * referenced types equivalence is checked separately. 3420d5caef5bSAndrii Nakryiko */ 3421d5caef5bSAndrii Nakryiko static bool btf_compat_array(struct btf_type *t1, struct btf_type *t2) 3422d5caef5bSAndrii Nakryiko { 3423d5caef5bSAndrii Nakryiko if (!btf_equal_common(t1, t2)) 3424d5caef5bSAndrii Nakryiko return false; 3425d5caef5bSAndrii Nakryiko 3426b03bc685SAndrii Nakryiko return btf_array(t1)->nelems == btf_array(t2)->nelems; 3427d5caef5bSAndrii Nakryiko } 3428d5caef5bSAndrii Nakryiko 3429d5caef5bSAndrii Nakryiko /* 3430d5caef5bSAndrii Nakryiko * Calculate type signature hash of FUNC_PROTO, including referenced type IDs, 3431d5caef5bSAndrii Nakryiko * under assumption that they were already resolved to canonical type IDs and 3432d5caef5bSAndrii Nakryiko * are not going to change. 3433d5caef5bSAndrii Nakryiko */ 34342fc3fc0bSAndrii Nakryiko static long btf_hash_fnproto(struct btf_type *t) 3435d5caef5bSAndrii Nakryiko { 3436b03bc685SAndrii Nakryiko const struct btf_param *member = btf_params(t); 3437b03bc685SAndrii Nakryiko __u16 vlen = btf_vlen(t); 34382fc3fc0bSAndrii Nakryiko long h = btf_hash_common(t); 3439d5caef5bSAndrii Nakryiko int i; 3440d5caef5bSAndrii Nakryiko 3441d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3442d5caef5bSAndrii Nakryiko h = hash_combine(h, member->name_off); 3443d5caef5bSAndrii Nakryiko h = hash_combine(h, member->type); 3444d5caef5bSAndrii Nakryiko member++; 3445d5caef5bSAndrii Nakryiko } 3446d5caef5bSAndrii Nakryiko return h; 3447d5caef5bSAndrii Nakryiko } 3448d5caef5bSAndrii Nakryiko 3449d5caef5bSAndrii Nakryiko /* 3450d5caef5bSAndrii Nakryiko * Check exact equality of two FUNC_PROTOs, taking into account referenced 3451d5caef5bSAndrii Nakryiko * type IDs, under assumption that they were already resolved to canonical 3452d5caef5bSAndrii Nakryiko * type IDs and are not going to change. 3453d5caef5bSAndrii Nakryiko * This function is called during reference types deduplication to compare 3454d5caef5bSAndrii Nakryiko * FUNC_PROTO to potential canonical representative. 3455d5caef5bSAndrii Nakryiko */ 34562fc3fc0bSAndrii Nakryiko static bool btf_equal_fnproto(struct btf_type *t1, struct btf_type *t2) 3457d5caef5bSAndrii Nakryiko { 3458b03bc685SAndrii Nakryiko const struct btf_param *m1, *m2; 3459d5caef5bSAndrii Nakryiko __u16 vlen; 3460d5caef5bSAndrii Nakryiko int i; 3461d5caef5bSAndrii Nakryiko 3462d5caef5bSAndrii Nakryiko if (!btf_equal_common(t1, t2)) 3463d5caef5bSAndrii Nakryiko return false; 3464d5caef5bSAndrii Nakryiko 3465b03bc685SAndrii Nakryiko vlen = btf_vlen(t1); 3466b03bc685SAndrii Nakryiko m1 = btf_params(t1); 3467b03bc685SAndrii Nakryiko m2 = btf_params(t2); 3468d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3469d5caef5bSAndrii Nakryiko if (m1->name_off != m2->name_off || m1->type != m2->type) 3470d5caef5bSAndrii Nakryiko return false; 3471d5caef5bSAndrii Nakryiko m1++; 3472d5caef5bSAndrii Nakryiko m2++; 3473d5caef5bSAndrii Nakryiko } 3474d5caef5bSAndrii Nakryiko return true; 3475d5caef5bSAndrii Nakryiko } 3476d5caef5bSAndrii Nakryiko 3477d5caef5bSAndrii Nakryiko /* 3478d5caef5bSAndrii Nakryiko * Check structural compatibility of two FUNC_PROTOs, ignoring referenced type 3479d5caef5bSAndrii Nakryiko * IDs. This check is performed during type graph equivalence check and 3480d5caef5bSAndrii Nakryiko * referenced types equivalence is checked separately. 3481d5caef5bSAndrii Nakryiko */ 34822fc3fc0bSAndrii Nakryiko static bool btf_compat_fnproto(struct btf_type *t1, struct btf_type *t2) 3483d5caef5bSAndrii Nakryiko { 3484b03bc685SAndrii Nakryiko const struct btf_param *m1, *m2; 3485d5caef5bSAndrii Nakryiko __u16 vlen; 3486d5caef5bSAndrii Nakryiko int i; 3487d5caef5bSAndrii Nakryiko 3488d5caef5bSAndrii Nakryiko /* skip return type ID */ 3489d5caef5bSAndrii Nakryiko if (t1->name_off != t2->name_off || t1->info != t2->info) 3490d5caef5bSAndrii Nakryiko return false; 3491d5caef5bSAndrii Nakryiko 3492b03bc685SAndrii Nakryiko vlen = btf_vlen(t1); 3493b03bc685SAndrii Nakryiko m1 = btf_params(t1); 3494b03bc685SAndrii Nakryiko m2 = btf_params(t2); 3495d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3496d5caef5bSAndrii Nakryiko if (m1->name_off != m2->name_off) 3497d5caef5bSAndrii Nakryiko return false; 3498d5caef5bSAndrii Nakryiko m1++; 3499d5caef5bSAndrii Nakryiko m2++; 3500d5caef5bSAndrii Nakryiko } 3501d5caef5bSAndrii Nakryiko return true; 3502d5caef5bSAndrii Nakryiko } 3503d5caef5bSAndrii Nakryiko 3504f86524efSAndrii Nakryiko /* Prepare split BTF for deduplication by calculating hashes of base BTF's 3505f86524efSAndrii Nakryiko * types and initializing the rest of the state (canonical type mapping) for 3506f86524efSAndrii Nakryiko * the fixed base BTF part. 3507f86524efSAndrii Nakryiko */ 3508f86524efSAndrii Nakryiko static int btf_dedup_prep(struct btf_dedup *d) 3509f86524efSAndrii Nakryiko { 3510f86524efSAndrii Nakryiko struct btf_type *t; 3511f86524efSAndrii Nakryiko int type_id; 3512f86524efSAndrii Nakryiko long h; 3513f86524efSAndrii Nakryiko 3514f86524efSAndrii Nakryiko if (!d->btf->base_btf) 3515f86524efSAndrii Nakryiko return 0; 3516f86524efSAndrii Nakryiko 3517f86524efSAndrii Nakryiko for (type_id = 1; type_id < d->btf->start_id; type_id++) { 3518f86524efSAndrii Nakryiko t = btf_type_by_id(d->btf, type_id); 3519f86524efSAndrii Nakryiko 3520f86524efSAndrii Nakryiko /* all base BTF types are self-canonical by definition */ 3521f86524efSAndrii Nakryiko d->map[type_id] = type_id; 3522f86524efSAndrii Nakryiko 3523f86524efSAndrii Nakryiko switch (btf_kind(t)) { 3524f86524efSAndrii Nakryiko case BTF_KIND_VAR: 3525f86524efSAndrii Nakryiko case BTF_KIND_DATASEC: 3526f86524efSAndrii Nakryiko /* VAR and DATASEC are never hash/deduplicated */ 3527f86524efSAndrii Nakryiko continue; 3528f86524efSAndrii Nakryiko case BTF_KIND_CONST: 3529f86524efSAndrii Nakryiko case BTF_KIND_VOLATILE: 3530f86524efSAndrii Nakryiko case BTF_KIND_RESTRICT: 3531f86524efSAndrii Nakryiko case BTF_KIND_PTR: 3532f86524efSAndrii Nakryiko case BTF_KIND_FWD: 3533f86524efSAndrii Nakryiko case BTF_KIND_TYPEDEF: 3534f86524efSAndrii Nakryiko case BTF_KIND_FUNC: 353522541a9eSIlya Leoshkevich case BTF_KIND_FLOAT: 3536f86524efSAndrii Nakryiko h = btf_hash_common(t); 3537f86524efSAndrii Nakryiko break; 3538f86524efSAndrii Nakryiko case BTF_KIND_INT: 3539f86524efSAndrii Nakryiko h = btf_hash_int(t); 3540f86524efSAndrii Nakryiko break; 3541f86524efSAndrii Nakryiko case BTF_KIND_ENUM: 3542f86524efSAndrii Nakryiko h = btf_hash_enum(t); 3543f86524efSAndrii Nakryiko break; 3544f86524efSAndrii Nakryiko case BTF_KIND_STRUCT: 3545f86524efSAndrii Nakryiko case BTF_KIND_UNION: 3546f86524efSAndrii Nakryiko h = btf_hash_struct(t); 3547f86524efSAndrii Nakryiko break; 3548f86524efSAndrii Nakryiko case BTF_KIND_ARRAY: 3549f86524efSAndrii Nakryiko h = btf_hash_array(t); 3550f86524efSAndrii Nakryiko break; 3551f86524efSAndrii Nakryiko case BTF_KIND_FUNC_PROTO: 3552f86524efSAndrii Nakryiko h = btf_hash_fnproto(t); 3553f86524efSAndrii Nakryiko break; 3554f86524efSAndrii Nakryiko default: 3555f86524efSAndrii Nakryiko pr_debug("unknown kind %d for type [%d]\n", btf_kind(t), type_id); 3556f86524efSAndrii Nakryiko return -EINVAL; 3557f86524efSAndrii Nakryiko } 3558f86524efSAndrii Nakryiko if (btf_dedup_table_add(d, h, type_id)) 3559f86524efSAndrii Nakryiko return -ENOMEM; 3560f86524efSAndrii Nakryiko } 3561f86524efSAndrii Nakryiko 3562f86524efSAndrii Nakryiko return 0; 3563f86524efSAndrii Nakryiko } 3564f86524efSAndrii Nakryiko 3565d5caef5bSAndrii Nakryiko /* 3566d5caef5bSAndrii Nakryiko * Deduplicate primitive types, that can't reference other types, by calculating 3567d5caef5bSAndrii Nakryiko * their type signature hash and comparing them with any possible canonical 3568d5caef5bSAndrii Nakryiko * candidate. If no canonical candidate matches, type itself is marked as 3569d5caef5bSAndrii Nakryiko * canonical and is added into `btf_dedup->dedup_table` as another candidate. 3570d5caef5bSAndrii Nakryiko */ 3571d5caef5bSAndrii Nakryiko static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id) 3572d5caef5bSAndrii Nakryiko { 3573740e69c3SAndrii Nakryiko struct btf_type *t = btf_type_by_id(d->btf, type_id); 35742fc3fc0bSAndrii Nakryiko struct hashmap_entry *hash_entry; 3575d5caef5bSAndrii Nakryiko struct btf_type *cand; 3576d5caef5bSAndrii Nakryiko /* if we don't find equivalent type, then we are canonical */ 3577d5caef5bSAndrii Nakryiko __u32 new_id = type_id; 35782fc3fc0bSAndrii Nakryiko __u32 cand_id; 35792fc3fc0bSAndrii Nakryiko long h; 3580d5caef5bSAndrii Nakryiko 3581b03bc685SAndrii Nakryiko switch (btf_kind(t)) { 3582d5caef5bSAndrii Nakryiko case BTF_KIND_CONST: 3583d5caef5bSAndrii Nakryiko case BTF_KIND_VOLATILE: 3584d5caef5bSAndrii Nakryiko case BTF_KIND_RESTRICT: 3585d5caef5bSAndrii Nakryiko case BTF_KIND_PTR: 3586d5caef5bSAndrii Nakryiko case BTF_KIND_TYPEDEF: 3587d5caef5bSAndrii Nakryiko case BTF_KIND_ARRAY: 3588d5caef5bSAndrii Nakryiko case BTF_KIND_STRUCT: 3589d5caef5bSAndrii Nakryiko case BTF_KIND_UNION: 3590d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC: 3591d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC_PROTO: 3592189cf5a4SAndrii Nakryiko case BTF_KIND_VAR: 3593189cf5a4SAndrii Nakryiko case BTF_KIND_DATASEC: 3594d5caef5bSAndrii Nakryiko return 0; 3595d5caef5bSAndrii Nakryiko 3596d5caef5bSAndrii Nakryiko case BTF_KIND_INT: 3597d5caef5bSAndrii Nakryiko h = btf_hash_int(t); 35982fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 35992fc3fc0bSAndrii Nakryiko cand_id = (__u32)(long)hash_entry->value; 3600740e69c3SAndrii Nakryiko cand = btf_type_by_id(d->btf, cand_id); 3601d5caef5bSAndrii Nakryiko if (btf_equal_int(t, cand)) { 36022fc3fc0bSAndrii Nakryiko new_id = cand_id; 3603d5caef5bSAndrii Nakryiko break; 3604d5caef5bSAndrii Nakryiko } 3605d5caef5bSAndrii Nakryiko } 3606d5caef5bSAndrii Nakryiko break; 3607d5caef5bSAndrii Nakryiko 3608d5caef5bSAndrii Nakryiko case BTF_KIND_ENUM: 3609d5caef5bSAndrii Nakryiko h = btf_hash_enum(t); 36102fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 36112fc3fc0bSAndrii Nakryiko cand_id = (__u32)(long)hash_entry->value; 3612740e69c3SAndrii Nakryiko cand = btf_type_by_id(d->btf, cand_id); 3613d5caef5bSAndrii Nakryiko if (btf_equal_enum(t, cand)) { 36142fc3fc0bSAndrii Nakryiko new_id = cand_id; 3615d5caef5bSAndrii Nakryiko break; 3616d5caef5bSAndrii Nakryiko } 36179768095bSAndrii Nakryiko if (d->opts.dont_resolve_fwds) 36189768095bSAndrii Nakryiko continue; 36199768095bSAndrii Nakryiko if (btf_compat_enum(t, cand)) { 36209768095bSAndrii Nakryiko if (btf_is_enum_fwd(t)) { 36219768095bSAndrii Nakryiko /* resolve fwd to full enum */ 36222fc3fc0bSAndrii Nakryiko new_id = cand_id; 36239768095bSAndrii Nakryiko break; 36249768095bSAndrii Nakryiko } 36259768095bSAndrii Nakryiko /* resolve canonical enum fwd to full enum */ 36262fc3fc0bSAndrii Nakryiko d->map[cand_id] = type_id; 36279768095bSAndrii Nakryiko } 3628d5caef5bSAndrii Nakryiko } 3629d5caef5bSAndrii Nakryiko break; 3630d5caef5bSAndrii Nakryiko 3631d5caef5bSAndrii Nakryiko case BTF_KIND_FWD: 363222541a9eSIlya Leoshkevich case BTF_KIND_FLOAT: 3633d5caef5bSAndrii Nakryiko h = btf_hash_common(t); 36342fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 36352fc3fc0bSAndrii Nakryiko cand_id = (__u32)(long)hash_entry->value; 3636740e69c3SAndrii Nakryiko cand = btf_type_by_id(d->btf, cand_id); 3637d5caef5bSAndrii Nakryiko if (btf_equal_common(t, cand)) { 36382fc3fc0bSAndrii Nakryiko new_id = cand_id; 3639d5caef5bSAndrii Nakryiko break; 3640d5caef5bSAndrii Nakryiko } 3641d5caef5bSAndrii Nakryiko } 3642d5caef5bSAndrii Nakryiko break; 3643d5caef5bSAndrii Nakryiko 3644d5caef5bSAndrii Nakryiko default: 3645d5caef5bSAndrii Nakryiko return -EINVAL; 3646d5caef5bSAndrii Nakryiko } 3647d5caef5bSAndrii Nakryiko 3648d5caef5bSAndrii Nakryiko d->map[type_id] = new_id; 3649d5caef5bSAndrii Nakryiko if (type_id == new_id && btf_dedup_table_add(d, h, type_id)) 3650d5caef5bSAndrii Nakryiko return -ENOMEM; 3651d5caef5bSAndrii Nakryiko 3652d5caef5bSAndrii Nakryiko return 0; 3653d5caef5bSAndrii Nakryiko } 3654d5caef5bSAndrii Nakryiko 3655d5caef5bSAndrii Nakryiko static int btf_dedup_prim_types(struct btf_dedup *d) 3656d5caef5bSAndrii Nakryiko { 3657d5caef5bSAndrii Nakryiko int i, err; 3658d5caef5bSAndrii Nakryiko 3659f86524efSAndrii Nakryiko for (i = 0; i < d->btf->nr_types; i++) { 3660f86524efSAndrii Nakryiko err = btf_dedup_prim_type(d, d->btf->start_id + i); 3661d5caef5bSAndrii Nakryiko if (err) 3662d5caef5bSAndrii Nakryiko return err; 3663d5caef5bSAndrii Nakryiko } 3664d5caef5bSAndrii Nakryiko return 0; 3665d5caef5bSAndrii Nakryiko } 3666d5caef5bSAndrii Nakryiko 3667d5caef5bSAndrii Nakryiko /* 3668d5caef5bSAndrii Nakryiko * Check whether type is already mapped into canonical one (could be to itself). 3669d5caef5bSAndrii Nakryiko */ 3670d5caef5bSAndrii Nakryiko static inline bool is_type_mapped(struct btf_dedup *d, uint32_t type_id) 3671d5caef5bSAndrii Nakryiko { 36725aab392cSAndrii Nakryiko return d->map[type_id] <= BTF_MAX_NR_TYPES; 3673d5caef5bSAndrii Nakryiko } 3674d5caef5bSAndrii Nakryiko 3675d5caef5bSAndrii Nakryiko /* 3676d5caef5bSAndrii Nakryiko * Resolve type ID into its canonical type ID, if any; otherwise return original 3677d5caef5bSAndrii Nakryiko * type ID. If type is FWD and is resolved into STRUCT/UNION already, follow 3678d5caef5bSAndrii Nakryiko * STRUCT/UNION link and resolve it into canonical type ID as well. 3679d5caef5bSAndrii Nakryiko */ 3680d5caef5bSAndrii Nakryiko static inline __u32 resolve_type_id(struct btf_dedup *d, __u32 type_id) 3681d5caef5bSAndrii Nakryiko { 3682d5caef5bSAndrii Nakryiko while (is_type_mapped(d, type_id) && d->map[type_id] != type_id) 3683d5caef5bSAndrii Nakryiko type_id = d->map[type_id]; 3684d5caef5bSAndrii Nakryiko return type_id; 3685d5caef5bSAndrii Nakryiko } 3686d5caef5bSAndrii Nakryiko 3687d5caef5bSAndrii Nakryiko /* 3688d5caef5bSAndrii Nakryiko * Resolve FWD to underlying STRUCT/UNION, if any; otherwise return original 3689d5caef5bSAndrii Nakryiko * type ID. 3690d5caef5bSAndrii Nakryiko */ 3691d5caef5bSAndrii Nakryiko static uint32_t resolve_fwd_id(struct btf_dedup *d, uint32_t type_id) 3692d5caef5bSAndrii Nakryiko { 3693d5caef5bSAndrii Nakryiko __u32 orig_type_id = type_id; 3694d5caef5bSAndrii Nakryiko 3695740e69c3SAndrii Nakryiko if (!btf_is_fwd(btf__type_by_id(d->btf, type_id))) 3696d5caef5bSAndrii Nakryiko return type_id; 3697d5caef5bSAndrii Nakryiko 3698d5caef5bSAndrii Nakryiko while (is_type_mapped(d, type_id) && d->map[type_id] != type_id) 3699d5caef5bSAndrii Nakryiko type_id = d->map[type_id]; 3700d5caef5bSAndrii Nakryiko 3701740e69c3SAndrii Nakryiko if (!btf_is_fwd(btf__type_by_id(d->btf, type_id))) 3702d5caef5bSAndrii Nakryiko return type_id; 3703d5caef5bSAndrii Nakryiko 3704d5caef5bSAndrii Nakryiko return orig_type_id; 3705d5caef5bSAndrii Nakryiko } 3706d5caef5bSAndrii Nakryiko 3707d5caef5bSAndrii Nakryiko 3708d5caef5bSAndrii Nakryiko static inline __u16 btf_fwd_kind(struct btf_type *t) 3709d5caef5bSAndrii Nakryiko { 3710b03bc685SAndrii Nakryiko return btf_kflag(t) ? BTF_KIND_UNION : BTF_KIND_STRUCT; 3711d5caef5bSAndrii Nakryiko } 3712d5caef5bSAndrii Nakryiko 37136b6e6b1dSAndrii Nakryiko /* Check if given two types are identical ARRAY definitions */ 37146b6e6b1dSAndrii Nakryiko static int btf_dedup_identical_arrays(struct btf_dedup *d, __u32 id1, __u32 id2) 37156b6e6b1dSAndrii Nakryiko { 37166b6e6b1dSAndrii Nakryiko struct btf_type *t1, *t2; 37176b6e6b1dSAndrii Nakryiko 37186b6e6b1dSAndrii Nakryiko t1 = btf_type_by_id(d->btf, id1); 37196b6e6b1dSAndrii Nakryiko t2 = btf_type_by_id(d->btf, id2); 37206b6e6b1dSAndrii Nakryiko if (!btf_is_array(t1) || !btf_is_array(t2)) 37216b6e6b1dSAndrii Nakryiko return 0; 37226b6e6b1dSAndrii Nakryiko 37236b6e6b1dSAndrii Nakryiko return btf_equal_array(t1, t2); 37246b6e6b1dSAndrii Nakryiko } 37256b6e6b1dSAndrii Nakryiko 3726d5caef5bSAndrii Nakryiko /* 3727d5caef5bSAndrii Nakryiko * Check equivalence of BTF type graph formed by candidate struct/union (we'll 3728d5caef5bSAndrii Nakryiko * call it "candidate graph" in this description for brevity) to a type graph 3729d5caef5bSAndrii Nakryiko * formed by (potential) canonical struct/union ("canonical graph" for brevity 3730d5caef5bSAndrii Nakryiko * here, though keep in mind that not all types in canonical graph are 3731d5caef5bSAndrii Nakryiko * necessarily canonical representatives themselves, some of them might be 3732d5caef5bSAndrii Nakryiko * duplicates or its uniqueness might not have been established yet). 3733d5caef5bSAndrii Nakryiko * Returns: 3734d5caef5bSAndrii Nakryiko * - >0, if type graphs are equivalent; 3735d5caef5bSAndrii Nakryiko * - 0, if not equivalent; 3736d5caef5bSAndrii Nakryiko * - <0, on error. 3737d5caef5bSAndrii Nakryiko * 3738d5caef5bSAndrii Nakryiko * Algorithm performs side-by-side DFS traversal of both type graphs and checks 3739d5caef5bSAndrii Nakryiko * equivalence of BTF types at each step. If at any point BTF types in candidate 3740d5caef5bSAndrii Nakryiko * and canonical graphs are not compatible structurally, whole graphs are 3741d5caef5bSAndrii Nakryiko * incompatible. If types are structurally equivalent (i.e., all information 3742d5caef5bSAndrii Nakryiko * except referenced type IDs is exactly the same), a mapping from `canon_id` to 3743d5caef5bSAndrii Nakryiko * a `cand_id` is recored in hypothetical mapping (`btf_dedup->hypot_map`). 3744d5caef5bSAndrii Nakryiko * If a type references other types, then those referenced types are checked 3745d5caef5bSAndrii Nakryiko * for equivalence recursively. 3746d5caef5bSAndrii Nakryiko * 3747d5caef5bSAndrii Nakryiko * During DFS traversal, if we find that for current `canon_id` type we 3748d5caef5bSAndrii Nakryiko * already have some mapping in hypothetical map, we check for two possible 3749d5caef5bSAndrii Nakryiko * situations: 3750d5caef5bSAndrii Nakryiko * - `canon_id` is mapped to exactly the same type as `cand_id`. This will 3751d5caef5bSAndrii Nakryiko * happen when type graphs have cycles. In this case we assume those two 3752d5caef5bSAndrii Nakryiko * types are equivalent. 3753d5caef5bSAndrii Nakryiko * - `canon_id` is mapped to different type. This is contradiction in our 3754d5caef5bSAndrii Nakryiko * hypothetical mapping, because same graph in canonical graph corresponds 3755d5caef5bSAndrii Nakryiko * to two different types in candidate graph, which for equivalent type 3756d5caef5bSAndrii Nakryiko * graphs shouldn't happen. This condition terminates equivalence check 3757d5caef5bSAndrii Nakryiko * with negative result. 3758d5caef5bSAndrii Nakryiko * 3759d5caef5bSAndrii Nakryiko * If type graphs traversal exhausts types to check and find no contradiction, 3760d5caef5bSAndrii Nakryiko * then type graphs are equivalent. 3761d5caef5bSAndrii Nakryiko * 3762d5caef5bSAndrii Nakryiko * When checking types for equivalence, there is one special case: FWD types. 3763d5caef5bSAndrii Nakryiko * If FWD type resolution is allowed and one of the types (either from canonical 3764d5caef5bSAndrii Nakryiko * or candidate graph) is FWD and other is STRUCT/UNION (depending on FWD's kind 3765d5caef5bSAndrii Nakryiko * flag) and their names match, hypothetical mapping is updated to point from 3766d5caef5bSAndrii Nakryiko * FWD to STRUCT/UNION. If graphs will be determined as equivalent successfully, 3767d5caef5bSAndrii Nakryiko * this mapping will be used to record FWD -> STRUCT/UNION mapping permanently. 3768d5caef5bSAndrii Nakryiko * 3769d5caef5bSAndrii Nakryiko * Technically, this could lead to incorrect FWD to STRUCT/UNION resolution, 3770d5caef5bSAndrii Nakryiko * if there are two exactly named (or anonymous) structs/unions that are 3771d5caef5bSAndrii Nakryiko * compatible structurally, one of which has FWD field, while other is concrete 3772d5caef5bSAndrii Nakryiko * STRUCT/UNION, but according to C sources they are different structs/unions 3773d5caef5bSAndrii Nakryiko * that are referencing different types with the same name. This is extremely 3774d5caef5bSAndrii Nakryiko * unlikely to happen, but btf_dedup API allows to disable FWD resolution if 3775d5caef5bSAndrii Nakryiko * this logic is causing problems. 3776d5caef5bSAndrii Nakryiko * 3777d5caef5bSAndrii Nakryiko * Doing FWD resolution means that both candidate and/or canonical graphs can 3778d5caef5bSAndrii Nakryiko * consists of portions of the graph that come from multiple compilation units. 3779d5caef5bSAndrii Nakryiko * This is due to the fact that types within single compilation unit are always 3780d5caef5bSAndrii Nakryiko * deduplicated and FWDs are already resolved, if referenced struct/union 3781d5caef5bSAndrii Nakryiko * definiton is available. So, if we had unresolved FWD and found corresponding 3782d5caef5bSAndrii Nakryiko * STRUCT/UNION, they will be from different compilation units. This 3783d5caef5bSAndrii Nakryiko * consequently means that when we "link" FWD to corresponding STRUCT/UNION, 3784d5caef5bSAndrii Nakryiko * type graph will likely have at least two different BTF types that describe 3785d5caef5bSAndrii Nakryiko * same type (e.g., most probably there will be two different BTF types for the 3786d5caef5bSAndrii Nakryiko * same 'int' primitive type) and could even have "overlapping" parts of type 3787d5caef5bSAndrii Nakryiko * graph that describe same subset of types. 3788d5caef5bSAndrii Nakryiko * 3789d5caef5bSAndrii Nakryiko * This in turn means that our assumption that each type in canonical graph 3790d5caef5bSAndrii Nakryiko * must correspond to exactly one type in candidate graph might not hold 3791d5caef5bSAndrii Nakryiko * anymore and will make it harder to detect contradictions using hypothetical 3792d5caef5bSAndrii Nakryiko * map. To handle this problem, we allow to follow FWD -> STRUCT/UNION 3793d5caef5bSAndrii Nakryiko * resolution only in canonical graph. FWDs in candidate graphs are never 3794d5caef5bSAndrii Nakryiko * resolved. To see why it's OK, let's check all possible situations w.r.t. FWDs 3795d5caef5bSAndrii Nakryiko * that can occur: 3796d5caef5bSAndrii Nakryiko * - Both types in canonical and candidate graphs are FWDs. If they are 3797d5caef5bSAndrii Nakryiko * structurally equivalent, then they can either be both resolved to the 3798d5caef5bSAndrii Nakryiko * same STRUCT/UNION or not resolved at all. In both cases they are 3799d5caef5bSAndrii Nakryiko * equivalent and there is no need to resolve FWD on candidate side. 3800d5caef5bSAndrii Nakryiko * - Both types in canonical and candidate graphs are concrete STRUCT/UNION, 3801d5caef5bSAndrii Nakryiko * so nothing to resolve as well, algorithm will check equivalence anyway. 3802d5caef5bSAndrii Nakryiko * - Type in canonical graph is FWD, while type in candidate is concrete 3803d5caef5bSAndrii Nakryiko * STRUCT/UNION. In this case candidate graph comes from single compilation 3804d5caef5bSAndrii Nakryiko * unit, so there is exactly one BTF type for each unique C type. After 3805d5caef5bSAndrii Nakryiko * resolving FWD into STRUCT/UNION, there might be more than one BTF type 3806d5caef5bSAndrii Nakryiko * in canonical graph mapping to single BTF type in candidate graph, but 3807d5caef5bSAndrii Nakryiko * because hypothetical mapping maps from canonical to candidate types, it's 3808d5caef5bSAndrii Nakryiko * alright, and we still maintain the property of having single `canon_id` 3809d5caef5bSAndrii Nakryiko * mapping to single `cand_id` (there could be two different `canon_id` 3810d5caef5bSAndrii Nakryiko * mapped to the same `cand_id`, but it's not contradictory). 3811d5caef5bSAndrii Nakryiko * - Type in canonical graph is concrete STRUCT/UNION, while type in candidate 3812d5caef5bSAndrii Nakryiko * graph is FWD. In this case we are just going to check compatibility of 3813d5caef5bSAndrii Nakryiko * STRUCT/UNION and corresponding FWD, and if they are compatible, we'll 3814d5caef5bSAndrii Nakryiko * assume that whatever STRUCT/UNION FWD resolves to must be equivalent to 3815d5caef5bSAndrii Nakryiko * a concrete STRUCT/UNION from canonical graph. If the rest of type graphs 3816d5caef5bSAndrii Nakryiko * turn out equivalent, we'll re-resolve FWD to concrete STRUCT/UNION from 3817d5caef5bSAndrii Nakryiko * canonical graph. 3818d5caef5bSAndrii Nakryiko */ 3819d5caef5bSAndrii Nakryiko static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id, 3820d5caef5bSAndrii Nakryiko __u32 canon_id) 3821d5caef5bSAndrii Nakryiko { 3822d5caef5bSAndrii Nakryiko struct btf_type *cand_type; 3823d5caef5bSAndrii Nakryiko struct btf_type *canon_type; 3824d5caef5bSAndrii Nakryiko __u32 hypot_type_id; 3825d5caef5bSAndrii Nakryiko __u16 cand_kind; 3826d5caef5bSAndrii Nakryiko __u16 canon_kind; 3827d5caef5bSAndrii Nakryiko int i, eq; 3828d5caef5bSAndrii Nakryiko 3829d5caef5bSAndrii Nakryiko /* if both resolve to the same canonical, they must be equivalent */ 3830d5caef5bSAndrii Nakryiko if (resolve_type_id(d, cand_id) == resolve_type_id(d, canon_id)) 3831d5caef5bSAndrii Nakryiko return 1; 3832d5caef5bSAndrii Nakryiko 3833d5caef5bSAndrii Nakryiko canon_id = resolve_fwd_id(d, canon_id); 3834d5caef5bSAndrii Nakryiko 3835d5caef5bSAndrii Nakryiko hypot_type_id = d->hypot_map[canon_id]; 38366b6e6b1dSAndrii Nakryiko if (hypot_type_id <= BTF_MAX_NR_TYPES) { 38376b6e6b1dSAndrii Nakryiko /* In some cases compiler will generate different DWARF types 38386b6e6b1dSAndrii Nakryiko * for *identical* array type definitions and use them for 38396b6e6b1dSAndrii Nakryiko * different fields within the *same* struct. This breaks type 38406b6e6b1dSAndrii Nakryiko * equivalence check, which makes an assumption that candidate 38416b6e6b1dSAndrii Nakryiko * types sub-graph has a consistent and deduped-by-compiler 38426b6e6b1dSAndrii Nakryiko * types within a single CU. So work around that by explicitly 38436b6e6b1dSAndrii Nakryiko * allowing identical array types here. 38446b6e6b1dSAndrii Nakryiko */ 38456b6e6b1dSAndrii Nakryiko return hypot_type_id == cand_id || 38466b6e6b1dSAndrii Nakryiko btf_dedup_identical_arrays(d, hypot_type_id, cand_id); 38476b6e6b1dSAndrii Nakryiko } 3848d5caef5bSAndrii Nakryiko 3849d5caef5bSAndrii Nakryiko if (btf_dedup_hypot_map_add(d, canon_id, cand_id)) 3850d5caef5bSAndrii Nakryiko return -ENOMEM; 3851d5caef5bSAndrii Nakryiko 3852740e69c3SAndrii Nakryiko cand_type = btf_type_by_id(d->btf, cand_id); 3853740e69c3SAndrii Nakryiko canon_type = btf_type_by_id(d->btf, canon_id); 3854b03bc685SAndrii Nakryiko cand_kind = btf_kind(cand_type); 3855b03bc685SAndrii Nakryiko canon_kind = btf_kind(canon_type); 3856d5caef5bSAndrii Nakryiko 3857d5caef5bSAndrii Nakryiko if (cand_type->name_off != canon_type->name_off) 3858d5caef5bSAndrii Nakryiko return 0; 3859d5caef5bSAndrii Nakryiko 3860d5caef5bSAndrii Nakryiko /* FWD <--> STRUCT/UNION equivalence check, if enabled */ 3861d5caef5bSAndrii Nakryiko if (!d->opts.dont_resolve_fwds 3862d5caef5bSAndrii Nakryiko && (cand_kind == BTF_KIND_FWD || canon_kind == BTF_KIND_FWD) 3863d5caef5bSAndrii Nakryiko && cand_kind != canon_kind) { 3864d5caef5bSAndrii Nakryiko __u16 real_kind; 3865d5caef5bSAndrii Nakryiko __u16 fwd_kind; 3866d5caef5bSAndrii Nakryiko 3867d5caef5bSAndrii Nakryiko if (cand_kind == BTF_KIND_FWD) { 3868d5caef5bSAndrii Nakryiko real_kind = canon_kind; 3869d5caef5bSAndrii Nakryiko fwd_kind = btf_fwd_kind(cand_type); 3870d5caef5bSAndrii Nakryiko } else { 3871d5caef5bSAndrii Nakryiko real_kind = cand_kind; 3872d5caef5bSAndrii Nakryiko fwd_kind = btf_fwd_kind(canon_type); 3873f86524efSAndrii Nakryiko /* we'd need to resolve base FWD to STRUCT/UNION */ 3874f86524efSAndrii Nakryiko if (fwd_kind == real_kind && canon_id < d->btf->start_id) 3875f86524efSAndrii Nakryiko d->hypot_adjust_canon = true; 3876d5caef5bSAndrii Nakryiko } 3877d5caef5bSAndrii Nakryiko return fwd_kind == real_kind; 3878d5caef5bSAndrii Nakryiko } 3879d5caef5bSAndrii Nakryiko 38809ec71c1cSAndrii Nakryiko if (cand_kind != canon_kind) 38819ec71c1cSAndrii Nakryiko return 0; 38829ec71c1cSAndrii Nakryiko 3883d5caef5bSAndrii Nakryiko switch (cand_kind) { 3884d5caef5bSAndrii Nakryiko case BTF_KIND_INT: 3885d5caef5bSAndrii Nakryiko return btf_equal_int(cand_type, canon_type); 3886d5caef5bSAndrii Nakryiko 3887d5caef5bSAndrii Nakryiko case BTF_KIND_ENUM: 38889768095bSAndrii Nakryiko if (d->opts.dont_resolve_fwds) 3889d5caef5bSAndrii Nakryiko return btf_equal_enum(cand_type, canon_type); 38909768095bSAndrii Nakryiko else 38919768095bSAndrii Nakryiko return btf_compat_enum(cand_type, canon_type); 3892d5caef5bSAndrii Nakryiko 3893d5caef5bSAndrii Nakryiko case BTF_KIND_FWD: 389422541a9eSIlya Leoshkevich case BTF_KIND_FLOAT: 3895d5caef5bSAndrii Nakryiko return btf_equal_common(cand_type, canon_type); 3896d5caef5bSAndrii Nakryiko 3897d5caef5bSAndrii Nakryiko case BTF_KIND_CONST: 3898d5caef5bSAndrii Nakryiko case BTF_KIND_VOLATILE: 3899d5caef5bSAndrii Nakryiko case BTF_KIND_RESTRICT: 3900d5caef5bSAndrii Nakryiko case BTF_KIND_PTR: 3901d5caef5bSAndrii Nakryiko case BTF_KIND_TYPEDEF: 3902d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC: 39039768095bSAndrii Nakryiko if (cand_type->info != canon_type->info) 39049768095bSAndrii Nakryiko return 0; 3905d5caef5bSAndrii Nakryiko return btf_dedup_is_equiv(d, cand_type->type, canon_type->type); 3906d5caef5bSAndrii Nakryiko 3907d5caef5bSAndrii Nakryiko case BTF_KIND_ARRAY: { 3908b03bc685SAndrii Nakryiko const struct btf_array *cand_arr, *canon_arr; 3909d5caef5bSAndrii Nakryiko 3910d5caef5bSAndrii Nakryiko if (!btf_compat_array(cand_type, canon_type)) 3911d5caef5bSAndrii Nakryiko return 0; 3912b03bc685SAndrii Nakryiko cand_arr = btf_array(cand_type); 3913b03bc685SAndrii Nakryiko canon_arr = btf_array(canon_type); 3914f86524efSAndrii Nakryiko eq = btf_dedup_is_equiv(d, cand_arr->index_type, canon_arr->index_type); 3915d5caef5bSAndrii Nakryiko if (eq <= 0) 3916d5caef5bSAndrii Nakryiko return eq; 3917d5caef5bSAndrii Nakryiko return btf_dedup_is_equiv(d, cand_arr->type, canon_arr->type); 3918d5caef5bSAndrii Nakryiko } 3919d5caef5bSAndrii Nakryiko 3920d5caef5bSAndrii Nakryiko case BTF_KIND_STRUCT: 3921d5caef5bSAndrii Nakryiko case BTF_KIND_UNION: { 3922b03bc685SAndrii Nakryiko const struct btf_member *cand_m, *canon_m; 3923d5caef5bSAndrii Nakryiko __u16 vlen; 3924d5caef5bSAndrii Nakryiko 392591097fbeSAndrii Nakryiko if (!btf_shallow_equal_struct(cand_type, canon_type)) 3926d5caef5bSAndrii Nakryiko return 0; 3927b03bc685SAndrii Nakryiko vlen = btf_vlen(cand_type); 3928b03bc685SAndrii Nakryiko cand_m = btf_members(cand_type); 3929b03bc685SAndrii Nakryiko canon_m = btf_members(canon_type); 3930d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3931d5caef5bSAndrii Nakryiko eq = btf_dedup_is_equiv(d, cand_m->type, canon_m->type); 3932d5caef5bSAndrii Nakryiko if (eq <= 0) 3933d5caef5bSAndrii Nakryiko return eq; 3934d5caef5bSAndrii Nakryiko cand_m++; 3935d5caef5bSAndrii Nakryiko canon_m++; 3936d5caef5bSAndrii Nakryiko } 3937d5caef5bSAndrii Nakryiko 3938d5caef5bSAndrii Nakryiko return 1; 3939d5caef5bSAndrii Nakryiko } 3940d5caef5bSAndrii Nakryiko 3941d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC_PROTO: { 3942b03bc685SAndrii Nakryiko const struct btf_param *cand_p, *canon_p; 3943d5caef5bSAndrii Nakryiko __u16 vlen; 3944d5caef5bSAndrii Nakryiko 3945d5caef5bSAndrii Nakryiko if (!btf_compat_fnproto(cand_type, canon_type)) 3946d5caef5bSAndrii Nakryiko return 0; 3947d5caef5bSAndrii Nakryiko eq = btf_dedup_is_equiv(d, cand_type->type, canon_type->type); 3948d5caef5bSAndrii Nakryiko if (eq <= 0) 3949d5caef5bSAndrii Nakryiko return eq; 3950b03bc685SAndrii Nakryiko vlen = btf_vlen(cand_type); 3951b03bc685SAndrii Nakryiko cand_p = btf_params(cand_type); 3952b03bc685SAndrii Nakryiko canon_p = btf_params(canon_type); 3953d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3954d5caef5bSAndrii Nakryiko eq = btf_dedup_is_equiv(d, cand_p->type, canon_p->type); 3955d5caef5bSAndrii Nakryiko if (eq <= 0) 3956d5caef5bSAndrii Nakryiko return eq; 3957d5caef5bSAndrii Nakryiko cand_p++; 3958d5caef5bSAndrii Nakryiko canon_p++; 3959d5caef5bSAndrii Nakryiko } 3960d5caef5bSAndrii Nakryiko return 1; 3961d5caef5bSAndrii Nakryiko } 3962d5caef5bSAndrii Nakryiko 3963d5caef5bSAndrii Nakryiko default: 3964d5caef5bSAndrii Nakryiko return -EINVAL; 3965d5caef5bSAndrii Nakryiko } 3966d5caef5bSAndrii Nakryiko return 0; 3967d5caef5bSAndrii Nakryiko } 3968d5caef5bSAndrii Nakryiko 3969d5caef5bSAndrii Nakryiko /* 3970d5caef5bSAndrii Nakryiko * Use hypothetical mapping, produced by successful type graph equivalence 3971d5caef5bSAndrii Nakryiko * check, to augment existing struct/union canonical mapping, where possible. 3972d5caef5bSAndrii Nakryiko * 3973d5caef5bSAndrii Nakryiko * If BTF_KIND_FWD resolution is allowed, this mapping is also used to record 3974d5caef5bSAndrii Nakryiko * FWD -> STRUCT/UNION correspondence as well. FWD resolution is bidirectional: 3975d5caef5bSAndrii Nakryiko * it doesn't matter if FWD type was part of canonical graph or candidate one, 3976d5caef5bSAndrii Nakryiko * we are recording the mapping anyway. As opposed to carefulness required 3977d5caef5bSAndrii Nakryiko * for struct/union correspondence mapping (described below), for FWD resolution 3978d5caef5bSAndrii Nakryiko * it's not important, as by the time that FWD type (reference type) will be 3979d5caef5bSAndrii Nakryiko * deduplicated all structs/unions will be deduped already anyway. 3980d5caef5bSAndrii Nakryiko * 3981d5caef5bSAndrii Nakryiko * Recording STRUCT/UNION mapping is purely a performance optimization and is 3982d5caef5bSAndrii Nakryiko * not required for correctness. It needs to be done carefully to ensure that 3983d5caef5bSAndrii Nakryiko * struct/union from candidate's type graph is not mapped into corresponding 3984d5caef5bSAndrii Nakryiko * struct/union from canonical type graph that itself hasn't been resolved into 3985d5caef5bSAndrii Nakryiko * canonical representative. The only guarantee we have is that canonical 3986d5caef5bSAndrii Nakryiko * struct/union was determined as canonical and that won't change. But any 3987d5caef5bSAndrii Nakryiko * types referenced through that struct/union fields could have been not yet 3988d5caef5bSAndrii Nakryiko * resolved, so in case like that it's too early to establish any kind of 3989d5caef5bSAndrii Nakryiko * correspondence between structs/unions. 3990d5caef5bSAndrii Nakryiko * 3991d5caef5bSAndrii Nakryiko * No canonical correspondence is derived for primitive types (they are already 3992d5caef5bSAndrii Nakryiko * deduplicated completely already anyway) or reference types (they rely on 3993d5caef5bSAndrii Nakryiko * stability of struct/union canonical relationship for equivalence checks). 3994d5caef5bSAndrii Nakryiko */ 3995d5caef5bSAndrii Nakryiko static void btf_dedup_merge_hypot_map(struct btf_dedup *d) 3996d5caef5bSAndrii Nakryiko { 3997f86524efSAndrii Nakryiko __u32 canon_type_id, targ_type_id; 3998d5caef5bSAndrii Nakryiko __u16 t_kind, c_kind; 3999d5caef5bSAndrii Nakryiko __u32 t_id, c_id; 4000d5caef5bSAndrii Nakryiko int i; 4001d5caef5bSAndrii Nakryiko 4002d5caef5bSAndrii Nakryiko for (i = 0; i < d->hypot_cnt; i++) { 4003f86524efSAndrii Nakryiko canon_type_id = d->hypot_list[i]; 4004f86524efSAndrii Nakryiko targ_type_id = d->hypot_map[canon_type_id]; 4005d5caef5bSAndrii Nakryiko t_id = resolve_type_id(d, targ_type_id); 4006f86524efSAndrii Nakryiko c_id = resolve_type_id(d, canon_type_id); 4007740e69c3SAndrii Nakryiko t_kind = btf_kind(btf__type_by_id(d->btf, t_id)); 4008740e69c3SAndrii Nakryiko c_kind = btf_kind(btf__type_by_id(d->btf, c_id)); 4009d5caef5bSAndrii Nakryiko /* 4010d5caef5bSAndrii Nakryiko * Resolve FWD into STRUCT/UNION. 4011d5caef5bSAndrii Nakryiko * It's ok to resolve FWD into STRUCT/UNION that's not yet 4012d5caef5bSAndrii Nakryiko * mapped to canonical representative (as opposed to 4013d5caef5bSAndrii Nakryiko * STRUCT/UNION <--> STRUCT/UNION mapping logic below), because 4014d5caef5bSAndrii Nakryiko * eventually that struct is going to be mapped and all resolved 4015d5caef5bSAndrii Nakryiko * FWDs will automatically resolve to correct canonical 4016d5caef5bSAndrii Nakryiko * representative. This will happen before ref type deduping, 4017d5caef5bSAndrii Nakryiko * which critically depends on stability of these mapping. This 4018d5caef5bSAndrii Nakryiko * stability is not a requirement for STRUCT/UNION equivalence 4019d5caef5bSAndrii Nakryiko * checks, though. 4020d5caef5bSAndrii Nakryiko */ 4021f86524efSAndrii Nakryiko 4022f86524efSAndrii Nakryiko /* if it's the split BTF case, we still need to point base FWD 4023f86524efSAndrii Nakryiko * to STRUCT/UNION in a split BTF, because FWDs from split BTF 4024f86524efSAndrii Nakryiko * will be resolved against base FWD. If we don't point base 4025f86524efSAndrii Nakryiko * canonical FWD to the resolved STRUCT/UNION, then all the 4026f86524efSAndrii Nakryiko * FWDs in split BTF won't be correctly resolved to a proper 4027f86524efSAndrii Nakryiko * STRUCT/UNION. 4028f86524efSAndrii Nakryiko */ 4029d5caef5bSAndrii Nakryiko if (t_kind != BTF_KIND_FWD && c_kind == BTF_KIND_FWD) 4030d5caef5bSAndrii Nakryiko d->map[c_id] = t_id; 4031f86524efSAndrii Nakryiko 4032f86524efSAndrii Nakryiko /* if graph equivalence determined that we'd need to adjust 4033f86524efSAndrii Nakryiko * base canonical types, then we need to only point base FWDs 4034f86524efSAndrii Nakryiko * to STRUCTs/UNIONs and do no more modifications. For all 4035f86524efSAndrii Nakryiko * other purposes the type graphs were not equivalent. 4036f86524efSAndrii Nakryiko */ 4037f86524efSAndrii Nakryiko if (d->hypot_adjust_canon) 4038f86524efSAndrii Nakryiko continue; 4039f86524efSAndrii Nakryiko 4040f86524efSAndrii Nakryiko if (t_kind == BTF_KIND_FWD && c_kind != BTF_KIND_FWD) 4041d5caef5bSAndrii Nakryiko d->map[t_id] = c_id; 4042d5caef5bSAndrii Nakryiko 4043d5caef5bSAndrii Nakryiko if ((t_kind == BTF_KIND_STRUCT || t_kind == BTF_KIND_UNION) && 4044d5caef5bSAndrii Nakryiko c_kind != BTF_KIND_FWD && 4045d5caef5bSAndrii Nakryiko is_type_mapped(d, c_id) && 4046d5caef5bSAndrii Nakryiko !is_type_mapped(d, t_id)) { 4047d5caef5bSAndrii Nakryiko /* 4048d5caef5bSAndrii Nakryiko * as a perf optimization, we can map struct/union 4049d5caef5bSAndrii Nakryiko * that's part of type graph we just verified for 4050d5caef5bSAndrii Nakryiko * equivalence. We can do that for struct/union that has 4051d5caef5bSAndrii Nakryiko * canonical representative only, though. 4052d5caef5bSAndrii Nakryiko */ 4053d5caef5bSAndrii Nakryiko d->map[t_id] = c_id; 4054d5caef5bSAndrii Nakryiko } 4055d5caef5bSAndrii Nakryiko } 4056d5caef5bSAndrii Nakryiko } 4057d5caef5bSAndrii Nakryiko 4058d5caef5bSAndrii Nakryiko /* 4059d5caef5bSAndrii Nakryiko * Deduplicate struct/union types. 4060d5caef5bSAndrii Nakryiko * 4061d5caef5bSAndrii Nakryiko * For each struct/union type its type signature hash is calculated, taking 4062d5caef5bSAndrii Nakryiko * into account type's name, size, number, order and names of fields, but 4063d5caef5bSAndrii Nakryiko * ignoring type ID's referenced from fields, because they might not be deduped 4064d5caef5bSAndrii Nakryiko * completely until after reference types deduplication phase. This type hash 4065d5caef5bSAndrii Nakryiko * is used to iterate over all potential canonical types, sharing same hash. 4066d5caef5bSAndrii Nakryiko * For each canonical candidate we check whether type graphs that they form 4067d5caef5bSAndrii Nakryiko * (through referenced types in fields and so on) are equivalent using algorithm 4068d5caef5bSAndrii Nakryiko * implemented in `btf_dedup_is_equiv`. If such equivalence is found and 4069d5caef5bSAndrii Nakryiko * BTF_KIND_FWD resolution is allowed, then hypothetical mapping 4070d5caef5bSAndrii Nakryiko * (btf_dedup->hypot_map) produced by aforementioned type graph equivalence 4071d5caef5bSAndrii Nakryiko * algorithm is used to record FWD -> STRUCT/UNION mapping. It's also used to 4072d5caef5bSAndrii Nakryiko * potentially map other structs/unions to their canonical representatives, 4073d5caef5bSAndrii Nakryiko * if such relationship hasn't yet been established. This speeds up algorithm 4074d5caef5bSAndrii Nakryiko * by eliminating some of the duplicate work. 4075d5caef5bSAndrii Nakryiko * 4076d5caef5bSAndrii Nakryiko * If no matching canonical representative was found, struct/union is marked 4077d5caef5bSAndrii Nakryiko * as canonical for itself and is added into btf_dedup->dedup_table hash map 4078d5caef5bSAndrii Nakryiko * for further look ups. 4079d5caef5bSAndrii Nakryiko */ 4080d5caef5bSAndrii Nakryiko static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id) 4081d5caef5bSAndrii Nakryiko { 408291097fbeSAndrii Nakryiko struct btf_type *cand_type, *t; 40832fc3fc0bSAndrii Nakryiko struct hashmap_entry *hash_entry; 4084d5caef5bSAndrii Nakryiko /* if we don't find equivalent type, then we are canonical */ 4085d5caef5bSAndrii Nakryiko __u32 new_id = type_id; 4086d5caef5bSAndrii Nakryiko __u16 kind; 40872fc3fc0bSAndrii Nakryiko long h; 4088d5caef5bSAndrii Nakryiko 4089d5caef5bSAndrii Nakryiko /* already deduped or is in process of deduping (loop detected) */ 40905aab392cSAndrii Nakryiko if (d->map[type_id] <= BTF_MAX_NR_TYPES) 4091d5caef5bSAndrii Nakryiko return 0; 4092d5caef5bSAndrii Nakryiko 4093740e69c3SAndrii Nakryiko t = btf_type_by_id(d->btf, type_id); 4094b03bc685SAndrii Nakryiko kind = btf_kind(t); 4095d5caef5bSAndrii Nakryiko 4096d5caef5bSAndrii Nakryiko if (kind != BTF_KIND_STRUCT && kind != BTF_KIND_UNION) 4097d5caef5bSAndrii Nakryiko return 0; 4098d5caef5bSAndrii Nakryiko 4099d5caef5bSAndrii Nakryiko h = btf_hash_struct(t); 41002fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 41012fc3fc0bSAndrii Nakryiko __u32 cand_id = (__u32)(long)hash_entry->value; 4102d5caef5bSAndrii Nakryiko int eq; 4103d5caef5bSAndrii Nakryiko 410491097fbeSAndrii Nakryiko /* 410591097fbeSAndrii Nakryiko * Even though btf_dedup_is_equiv() checks for 410691097fbeSAndrii Nakryiko * btf_shallow_equal_struct() internally when checking two 410791097fbeSAndrii Nakryiko * structs (unions) for equivalence, we need to guard here 410891097fbeSAndrii Nakryiko * from picking matching FWD type as a dedup candidate. 410991097fbeSAndrii Nakryiko * This can happen due to hash collision. In such case just 411091097fbeSAndrii Nakryiko * relying on btf_dedup_is_equiv() would lead to potentially 411191097fbeSAndrii Nakryiko * creating a loop (FWD -> STRUCT and STRUCT -> FWD), because 411291097fbeSAndrii Nakryiko * FWD and compatible STRUCT/UNION are considered equivalent. 411391097fbeSAndrii Nakryiko */ 4114740e69c3SAndrii Nakryiko cand_type = btf_type_by_id(d->btf, cand_id); 411591097fbeSAndrii Nakryiko if (!btf_shallow_equal_struct(t, cand_type)) 411691097fbeSAndrii Nakryiko continue; 411791097fbeSAndrii Nakryiko 4118d5caef5bSAndrii Nakryiko btf_dedup_clear_hypot_map(d); 41192fc3fc0bSAndrii Nakryiko eq = btf_dedup_is_equiv(d, type_id, cand_id); 4120d5caef5bSAndrii Nakryiko if (eq < 0) 4121d5caef5bSAndrii Nakryiko return eq; 4122d5caef5bSAndrii Nakryiko if (!eq) 4123d5caef5bSAndrii Nakryiko continue; 4124d5caef5bSAndrii Nakryiko btf_dedup_merge_hypot_map(d); 4125f86524efSAndrii Nakryiko if (d->hypot_adjust_canon) /* not really equivalent */ 4126f86524efSAndrii Nakryiko continue; 4127f86524efSAndrii Nakryiko new_id = cand_id; 4128d5caef5bSAndrii Nakryiko break; 4129d5caef5bSAndrii Nakryiko } 4130d5caef5bSAndrii Nakryiko 4131d5caef5bSAndrii Nakryiko d->map[type_id] = new_id; 4132d5caef5bSAndrii Nakryiko if (type_id == new_id && btf_dedup_table_add(d, h, type_id)) 4133d5caef5bSAndrii Nakryiko return -ENOMEM; 4134d5caef5bSAndrii Nakryiko 4135d5caef5bSAndrii Nakryiko return 0; 4136d5caef5bSAndrii Nakryiko } 4137d5caef5bSAndrii Nakryiko 4138d5caef5bSAndrii Nakryiko static int btf_dedup_struct_types(struct btf_dedup *d) 4139d5caef5bSAndrii Nakryiko { 4140d5caef5bSAndrii Nakryiko int i, err; 4141d5caef5bSAndrii Nakryiko 4142f86524efSAndrii Nakryiko for (i = 0; i < d->btf->nr_types; i++) { 4143f86524efSAndrii Nakryiko err = btf_dedup_struct_type(d, d->btf->start_id + i); 4144d5caef5bSAndrii Nakryiko if (err) 4145d5caef5bSAndrii Nakryiko return err; 4146d5caef5bSAndrii Nakryiko } 4147d5caef5bSAndrii Nakryiko return 0; 4148d5caef5bSAndrii Nakryiko } 4149d5caef5bSAndrii Nakryiko 4150d5caef5bSAndrii Nakryiko /* 4151d5caef5bSAndrii Nakryiko * Deduplicate reference type. 4152d5caef5bSAndrii Nakryiko * 4153d5caef5bSAndrii Nakryiko * Once all primitive and struct/union types got deduplicated, we can easily 4154d5caef5bSAndrii Nakryiko * deduplicate all other (reference) BTF types. This is done in two steps: 4155d5caef5bSAndrii Nakryiko * 4156d5caef5bSAndrii Nakryiko * 1. Resolve all referenced type IDs into their canonical type IDs. This 4157d5caef5bSAndrii Nakryiko * resolution can be done either immediately for primitive or struct/union types 4158d5caef5bSAndrii Nakryiko * (because they were deduped in previous two phases) or recursively for 4159d5caef5bSAndrii Nakryiko * reference types. Recursion will always terminate at either primitive or 4160d5caef5bSAndrii Nakryiko * struct/union type, at which point we can "unwind" chain of reference types 4161d5caef5bSAndrii Nakryiko * one by one. There is no danger of encountering cycles because in C type 4162d5caef5bSAndrii Nakryiko * system the only way to form type cycle is through struct/union, so any chain 4163d5caef5bSAndrii Nakryiko * of reference types, even those taking part in a type cycle, will inevitably 4164d5caef5bSAndrii Nakryiko * reach struct/union at some point. 4165d5caef5bSAndrii Nakryiko * 4166d5caef5bSAndrii Nakryiko * 2. Once all referenced type IDs are resolved into canonical ones, BTF type 4167d5caef5bSAndrii Nakryiko * becomes "stable", in the sense that no further deduplication will cause 4168d5caef5bSAndrii Nakryiko * any changes to it. With that, it's now possible to calculate type's signature 4169d5caef5bSAndrii Nakryiko * hash (this time taking into account referenced type IDs) and loop over all 4170d5caef5bSAndrii Nakryiko * potential canonical representatives. If no match was found, current type 4171d5caef5bSAndrii Nakryiko * will become canonical representative of itself and will be added into 4172d5caef5bSAndrii Nakryiko * btf_dedup->dedup_table as another possible canonical representative. 4173d5caef5bSAndrii Nakryiko */ 4174d5caef5bSAndrii Nakryiko static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id) 4175d5caef5bSAndrii Nakryiko { 41762fc3fc0bSAndrii Nakryiko struct hashmap_entry *hash_entry; 41772fc3fc0bSAndrii Nakryiko __u32 new_id = type_id, cand_id; 4178d5caef5bSAndrii Nakryiko struct btf_type *t, *cand; 4179d5caef5bSAndrii Nakryiko /* if we don't find equivalent type, then we are representative type */ 41803d8669e6SDan Carpenter int ref_type_id; 41812fc3fc0bSAndrii Nakryiko long h; 4182d5caef5bSAndrii Nakryiko 4183d5caef5bSAndrii Nakryiko if (d->map[type_id] == BTF_IN_PROGRESS_ID) 4184d5caef5bSAndrii Nakryiko return -ELOOP; 41855aab392cSAndrii Nakryiko if (d->map[type_id] <= BTF_MAX_NR_TYPES) 4186d5caef5bSAndrii Nakryiko return resolve_type_id(d, type_id); 4187d5caef5bSAndrii Nakryiko 4188740e69c3SAndrii Nakryiko t = btf_type_by_id(d->btf, type_id); 4189d5caef5bSAndrii Nakryiko d->map[type_id] = BTF_IN_PROGRESS_ID; 4190d5caef5bSAndrii Nakryiko 4191b03bc685SAndrii Nakryiko switch (btf_kind(t)) { 4192d5caef5bSAndrii Nakryiko case BTF_KIND_CONST: 4193d5caef5bSAndrii Nakryiko case BTF_KIND_VOLATILE: 4194d5caef5bSAndrii Nakryiko case BTF_KIND_RESTRICT: 4195d5caef5bSAndrii Nakryiko case BTF_KIND_PTR: 4196d5caef5bSAndrii Nakryiko case BTF_KIND_TYPEDEF: 4197d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC: 4198d5caef5bSAndrii Nakryiko ref_type_id = btf_dedup_ref_type(d, t->type); 4199d5caef5bSAndrii Nakryiko if (ref_type_id < 0) 4200d5caef5bSAndrii Nakryiko return ref_type_id; 4201d5caef5bSAndrii Nakryiko t->type = ref_type_id; 4202d5caef5bSAndrii Nakryiko 4203d5caef5bSAndrii Nakryiko h = btf_hash_common(t); 42042fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 42052fc3fc0bSAndrii Nakryiko cand_id = (__u32)(long)hash_entry->value; 4206740e69c3SAndrii Nakryiko cand = btf_type_by_id(d->btf, cand_id); 4207d5caef5bSAndrii Nakryiko if (btf_equal_common(t, cand)) { 42082fc3fc0bSAndrii Nakryiko new_id = cand_id; 4209d5caef5bSAndrii Nakryiko break; 4210d5caef5bSAndrii Nakryiko } 4211d5caef5bSAndrii Nakryiko } 4212d5caef5bSAndrii Nakryiko break; 4213d5caef5bSAndrii Nakryiko 4214d5caef5bSAndrii Nakryiko case BTF_KIND_ARRAY: { 4215b03bc685SAndrii Nakryiko struct btf_array *info = btf_array(t); 4216d5caef5bSAndrii Nakryiko 4217d5caef5bSAndrii Nakryiko ref_type_id = btf_dedup_ref_type(d, info->type); 4218d5caef5bSAndrii Nakryiko if (ref_type_id < 0) 4219d5caef5bSAndrii Nakryiko return ref_type_id; 4220d5caef5bSAndrii Nakryiko info->type = ref_type_id; 4221d5caef5bSAndrii Nakryiko 4222d5caef5bSAndrii Nakryiko ref_type_id = btf_dedup_ref_type(d, info->index_type); 4223d5caef5bSAndrii Nakryiko if (ref_type_id < 0) 4224d5caef5bSAndrii Nakryiko return ref_type_id; 4225d5caef5bSAndrii Nakryiko info->index_type = ref_type_id; 4226d5caef5bSAndrii Nakryiko 4227d5caef5bSAndrii Nakryiko h = btf_hash_array(t); 42282fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 42292fc3fc0bSAndrii Nakryiko cand_id = (__u32)(long)hash_entry->value; 4230740e69c3SAndrii Nakryiko cand = btf_type_by_id(d->btf, cand_id); 4231d5caef5bSAndrii Nakryiko if (btf_equal_array(t, cand)) { 42322fc3fc0bSAndrii Nakryiko new_id = cand_id; 4233d5caef5bSAndrii Nakryiko break; 4234d5caef5bSAndrii Nakryiko } 4235d5caef5bSAndrii Nakryiko } 4236d5caef5bSAndrii Nakryiko break; 4237d5caef5bSAndrii Nakryiko } 4238d5caef5bSAndrii Nakryiko 4239d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC_PROTO: { 4240d5caef5bSAndrii Nakryiko struct btf_param *param; 4241d5caef5bSAndrii Nakryiko __u16 vlen; 4242d5caef5bSAndrii Nakryiko int i; 4243d5caef5bSAndrii Nakryiko 4244d5caef5bSAndrii Nakryiko ref_type_id = btf_dedup_ref_type(d, t->type); 4245d5caef5bSAndrii Nakryiko if (ref_type_id < 0) 4246d5caef5bSAndrii Nakryiko return ref_type_id; 4247d5caef5bSAndrii Nakryiko t->type = ref_type_id; 4248d5caef5bSAndrii Nakryiko 4249b03bc685SAndrii Nakryiko vlen = btf_vlen(t); 4250b03bc685SAndrii Nakryiko param = btf_params(t); 4251d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 4252d5caef5bSAndrii Nakryiko ref_type_id = btf_dedup_ref_type(d, param->type); 4253d5caef5bSAndrii Nakryiko if (ref_type_id < 0) 4254d5caef5bSAndrii Nakryiko return ref_type_id; 4255d5caef5bSAndrii Nakryiko param->type = ref_type_id; 4256d5caef5bSAndrii Nakryiko param++; 4257d5caef5bSAndrii Nakryiko } 4258d5caef5bSAndrii Nakryiko 4259d5caef5bSAndrii Nakryiko h = btf_hash_fnproto(t); 42602fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 42612fc3fc0bSAndrii Nakryiko cand_id = (__u32)(long)hash_entry->value; 4262740e69c3SAndrii Nakryiko cand = btf_type_by_id(d->btf, cand_id); 4263d5caef5bSAndrii Nakryiko if (btf_equal_fnproto(t, cand)) { 42642fc3fc0bSAndrii Nakryiko new_id = cand_id; 4265d5caef5bSAndrii Nakryiko break; 4266d5caef5bSAndrii Nakryiko } 4267d5caef5bSAndrii Nakryiko } 4268d5caef5bSAndrii Nakryiko break; 4269d5caef5bSAndrii Nakryiko } 4270d5caef5bSAndrii Nakryiko 4271d5caef5bSAndrii Nakryiko default: 4272d5caef5bSAndrii Nakryiko return -EINVAL; 4273d5caef5bSAndrii Nakryiko } 4274d5caef5bSAndrii Nakryiko 4275d5caef5bSAndrii Nakryiko d->map[type_id] = new_id; 4276d5caef5bSAndrii Nakryiko if (type_id == new_id && btf_dedup_table_add(d, h, type_id)) 4277d5caef5bSAndrii Nakryiko return -ENOMEM; 4278d5caef5bSAndrii Nakryiko 4279d5caef5bSAndrii Nakryiko return new_id; 4280d5caef5bSAndrii Nakryiko } 4281d5caef5bSAndrii Nakryiko 4282d5caef5bSAndrii Nakryiko static int btf_dedup_ref_types(struct btf_dedup *d) 4283d5caef5bSAndrii Nakryiko { 4284d5caef5bSAndrii Nakryiko int i, err; 4285d5caef5bSAndrii Nakryiko 4286f86524efSAndrii Nakryiko for (i = 0; i < d->btf->nr_types; i++) { 4287f86524efSAndrii Nakryiko err = btf_dedup_ref_type(d, d->btf->start_id + i); 4288d5caef5bSAndrii Nakryiko if (err < 0) 4289d5caef5bSAndrii Nakryiko return err; 4290d5caef5bSAndrii Nakryiko } 42912fc3fc0bSAndrii Nakryiko /* we won't need d->dedup_table anymore */ 42922fc3fc0bSAndrii Nakryiko hashmap__free(d->dedup_table); 42932fc3fc0bSAndrii Nakryiko d->dedup_table = NULL; 4294d5caef5bSAndrii Nakryiko return 0; 4295d5caef5bSAndrii Nakryiko } 4296d5caef5bSAndrii Nakryiko 4297d5caef5bSAndrii Nakryiko /* 4298d5caef5bSAndrii Nakryiko * Compact types. 4299d5caef5bSAndrii Nakryiko * 4300d5caef5bSAndrii Nakryiko * After we established for each type its corresponding canonical representative 4301d5caef5bSAndrii Nakryiko * type, we now can eliminate types that are not canonical and leave only 4302d5caef5bSAndrii Nakryiko * canonical ones layed out sequentially in memory by copying them over 4303d5caef5bSAndrii Nakryiko * duplicates. During compaction btf_dedup->hypot_map array is reused to store 4304d5caef5bSAndrii Nakryiko * a map from original type ID to a new compacted type ID, which will be used 4305d5caef5bSAndrii Nakryiko * during next phase to "fix up" type IDs, referenced from struct/union and 4306d5caef5bSAndrii Nakryiko * reference types. 4307d5caef5bSAndrii Nakryiko */ 4308d5caef5bSAndrii Nakryiko static int btf_dedup_compact_types(struct btf_dedup *d) 4309d5caef5bSAndrii Nakryiko { 4310740e69c3SAndrii Nakryiko __u32 *new_offs; 4311f86524efSAndrii Nakryiko __u32 next_type_id = d->btf->start_id; 4312f86524efSAndrii Nakryiko const struct btf_type *t; 4313740e69c3SAndrii Nakryiko void *p; 4314f86524efSAndrii Nakryiko int i, id, len; 4315d5caef5bSAndrii Nakryiko 4316d5caef5bSAndrii Nakryiko /* we are going to reuse hypot_map to store compaction remapping */ 4317d5caef5bSAndrii Nakryiko d->hypot_map[0] = 0; 4318f86524efSAndrii Nakryiko /* base BTF types are not renumbered */ 4319f86524efSAndrii Nakryiko for (id = 1; id < d->btf->start_id; id++) 4320f86524efSAndrii Nakryiko d->hypot_map[id] = id; 4321f86524efSAndrii Nakryiko for (i = 0, id = d->btf->start_id; i < d->btf->nr_types; i++, id++) 4322f86524efSAndrii Nakryiko d->hypot_map[id] = BTF_UNPROCESSED_ID; 4323d5caef5bSAndrii Nakryiko 4324740e69c3SAndrii Nakryiko p = d->btf->types_data; 4325d5caef5bSAndrii Nakryiko 4326f86524efSAndrii Nakryiko for (i = 0, id = d->btf->start_id; i < d->btf->nr_types; i++, id++) { 4327f86524efSAndrii Nakryiko if (d->map[id] != id) 4328d5caef5bSAndrii Nakryiko continue; 4329d5caef5bSAndrii Nakryiko 4330f86524efSAndrii Nakryiko t = btf__type_by_id(d->btf, id); 4331f86524efSAndrii Nakryiko len = btf_type_size(t); 4332d5caef5bSAndrii Nakryiko if (len < 0) 4333d5caef5bSAndrii Nakryiko return len; 4334d5caef5bSAndrii Nakryiko 4335f86524efSAndrii Nakryiko memmove(p, t, len); 4336f86524efSAndrii Nakryiko d->hypot_map[id] = next_type_id; 4337f86524efSAndrii Nakryiko d->btf->type_offs[next_type_id - d->btf->start_id] = p - d->btf->types_data; 4338d5caef5bSAndrii Nakryiko p += len; 4339d5caef5bSAndrii Nakryiko next_type_id++; 4340d5caef5bSAndrii Nakryiko } 4341d5caef5bSAndrii Nakryiko 4342d5caef5bSAndrii Nakryiko /* shrink struct btf's internal types index and update btf_header */ 4343f86524efSAndrii Nakryiko d->btf->nr_types = next_type_id - d->btf->start_id; 4344ba451366SAndrii Nakryiko d->btf->type_offs_cap = d->btf->nr_types; 4345740e69c3SAndrii Nakryiko d->btf->hdr->type_len = p - d->btf->types_data; 4346740e69c3SAndrii Nakryiko new_offs = libbpf_reallocarray(d->btf->type_offs, d->btf->type_offs_cap, 4347740e69c3SAndrii Nakryiko sizeof(*new_offs)); 4348f86524efSAndrii Nakryiko if (d->btf->type_offs_cap && !new_offs) 4349d5caef5bSAndrii Nakryiko return -ENOMEM; 4350740e69c3SAndrii Nakryiko d->btf->type_offs = new_offs; 4351919d2b1dSAndrii Nakryiko d->btf->hdr->str_off = d->btf->hdr->type_len; 4352b8604247SAndrii Nakryiko d->btf->raw_size = d->btf->hdr->hdr_len + d->btf->hdr->type_len + d->btf->hdr->str_len; 4353d5caef5bSAndrii Nakryiko return 0; 4354d5caef5bSAndrii Nakryiko } 4355d5caef5bSAndrii Nakryiko 4356d5caef5bSAndrii Nakryiko /* 4357d5caef5bSAndrii Nakryiko * Figure out final (deduplicated and compacted) type ID for provided original 4358d5caef5bSAndrii Nakryiko * `type_id` by first resolving it into corresponding canonical type ID and 4359d5caef5bSAndrii Nakryiko * then mapping it to a deduplicated type ID, stored in btf_dedup->hypot_map, 4360d5caef5bSAndrii Nakryiko * which is populated during compaction phase. 4361d5caef5bSAndrii Nakryiko */ 4362f36e99a4SAndrii Nakryiko static int btf_dedup_remap_type_id(__u32 *type_id, void *ctx) 4363d5caef5bSAndrii Nakryiko { 4364f36e99a4SAndrii Nakryiko struct btf_dedup *d = ctx; 4365d5caef5bSAndrii Nakryiko __u32 resolved_type_id, new_type_id; 4366d5caef5bSAndrii Nakryiko 4367f36e99a4SAndrii Nakryiko resolved_type_id = resolve_type_id(d, *type_id); 4368d5caef5bSAndrii Nakryiko new_type_id = d->hypot_map[resolved_type_id]; 43695aab392cSAndrii Nakryiko if (new_type_id > BTF_MAX_NR_TYPES) 4370d5caef5bSAndrii Nakryiko return -EINVAL; 4371f36e99a4SAndrii Nakryiko 4372f36e99a4SAndrii Nakryiko *type_id = new_type_id; 4373f36e99a4SAndrii Nakryiko return 0; 4374d5caef5bSAndrii Nakryiko } 4375d5caef5bSAndrii Nakryiko 4376d5caef5bSAndrii Nakryiko /* 4377d5caef5bSAndrii Nakryiko * Remap referenced type IDs into deduped type IDs. 4378d5caef5bSAndrii Nakryiko * 4379d5caef5bSAndrii Nakryiko * After BTF types are deduplicated and compacted, their final type IDs may 4380d5caef5bSAndrii Nakryiko * differ from original ones. The map from original to a corresponding 4381d5caef5bSAndrii Nakryiko * deduped type ID is stored in btf_dedup->hypot_map and is populated during 4382d5caef5bSAndrii Nakryiko * compaction phase. During remapping phase we are rewriting all type IDs 4383d5caef5bSAndrii Nakryiko * referenced from any BTF type (e.g., struct fields, func proto args, etc) to 4384d5caef5bSAndrii Nakryiko * their final deduped type IDs. 4385d5caef5bSAndrii Nakryiko */ 4386d5caef5bSAndrii Nakryiko static int btf_dedup_remap_types(struct btf_dedup *d) 4387d5caef5bSAndrii Nakryiko { 4388d5caef5bSAndrii Nakryiko int i, r; 4389d5caef5bSAndrii Nakryiko 4390f86524efSAndrii Nakryiko for (i = 0; i < d->btf->nr_types; i++) { 4391f36e99a4SAndrii Nakryiko struct btf_type *t = btf_type_by_id(d->btf, d->btf->start_id + i); 4392f36e99a4SAndrii Nakryiko 4393f36e99a4SAndrii Nakryiko r = btf_type_visit_type_ids(t, btf_dedup_remap_type_id, d); 4394f36e99a4SAndrii Nakryiko if (r) 4395d5caef5bSAndrii Nakryiko return r; 4396d5caef5bSAndrii Nakryiko } 4397f36e99a4SAndrii Nakryiko 4398f36e99a4SAndrii Nakryiko if (!d->btf_ext) 4399f36e99a4SAndrii Nakryiko return 0; 4400f36e99a4SAndrii Nakryiko 4401f36e99a4SAndrii Nakryiko r = btf_ext_visit_type_ids(d->btf_ext, btf_dedup_remap_type_id, d); 4402f36e99a4SAndrii Nakryiko if (r) 4403f36e99a4SAndrii Nakryiko return r; 4404f36e99a4SAndrii Nakryiko 4405d5caef5bSAndrii Nakryiko return 0; 4406d5caef5bSAndrii Nakryiko } 4407fb2426adSMartin KaFai Lau 4408fb2426adSMartin KaFai Lau /* 4409fb2426adSMartin KaFai Lau * Probe few well-known locations for vmlinux kernel image and try to load BTF 4410fb2426adSMartin KaFai Lau * data out of it to use for target BTF. 4411fb2426adSMartin KaFai Lau */ 4412fb2426adSMartin KaFai Lau struct btf *libbpf_find_kernel_btf(void) 4413fb2426adSMartin KaFai Lau { 4414fb2426adSMartin KaFai Lau struct { 4415fb2426adSMartin KaFai Lau const char *path_fmt; 4416fb2426adSMartin KaFai Lau bool raw_btf; 4417fb2426adSMartin KaFai Lau } locations[] = { 4418fb2426adSMartin KaFai Lau /* try canonical vmlinux BTF through sysfs first */ 4419fb2426adSMartin KaFai Lau { "/sys/kernel/btf/vmlinux", true /* raw BTF */ }, 4420fb2426adSMartin KaFai Lau /* fall back to trying to find vmlinux ELF on disk otherwise */ 4421fb2426adSMartin KaFai Lau { "/boot/vmlinux-%1$s" }, 4422fb2426adSMartin KaFai Lau { "/lib/modules/%1$s/vmlinux-%1$s" }, 4423fb2426adSMartin KaFai Lau { "/lib/modules/%1$s/build/vmlinux" }, 4424fb2426adSMartin KaFai Lau { "/usr/lib/modules/%1$s/kernel/vmlinux" }, 4425fb2426adSMartin KaFai Lau { "/usr/lib/debug/boot/vmlinux-%1$s" }, 4426fb2426adSMartin KaFai Lau { "/usr/lib/debug/boot/vmlinux-%1$s.debug" }, 4427fb2426adSMartin KaFai Lau { "/usr/lib/debug/lib/modules/%1$s/vmlinux" }, 4428fb2426adSMartin KaFai Lau }; 4429fb2426adSMartin KaFai Lau char path[PATH_MAX + 1]; 4430fb2426adSMartin KaFai Lau struct utsname buf; 4431fb2426adSMartin KaFai Lau struct btf *btf; 4432e9fc3ce9SAndrii Nakryiko int i, err; 4433fb2426adSMartin KaFai Lau 4434fb2426adSMartin KaFai Lau uname(&buf); 4435fb2426adSMartin KaFai Lau 4436fb2426adSMartin KaFai Lau for (i = 0; i < ARRAY_SIZE(locations); i++) { 4437fb2426adSMartin KaFai Lau snprintf(path, PATH_MAX, locations[i].path_fmt, buf.release); 4438fb2426adSMartin KaFai Lau 4439fb2426adSMartin KaFai Lau if (access(path, R_OK)) 4440fb2426adSMartin KaFai Lau continue; 4441fb2426adSMartin KaFai Lau 4442fb2426adSMartin KaFai Lau if (locations[i].raw_btf) 444394a1feddSAndrii Nakryiko btf = btf__parse_raw(path); 4444fb2426adSMartin KaFai Lau else 4445fb2426adSMartin KaFai Lau btf = btf__parse_elf(path, NULL); 4446e9fc3ce9SAndrii Nakryiko err = libbpf_get_error(btf); 4447e9fc3ce9SAndrii Nakryiko pr_debug("loading kernel BTF '%s': %d\n", path, err); 4448e9fc3ce9SAndrii Nakryiko if (err) 4449fb2426adSMartin KaFai Lau continue; 4450fb2426adSMartin KaFai Lau 4451fb2426adSMartin KaFai Lau return btf; 4452fb2426adSMartin KaFai Lau } 4453fb2426adSMartin KaFai Lau 4454fb2426adSMartin KaFai Lau pr_warn("failed to find valid kernel BTF\n"); 4455e9fc3ce9SAndrii Nakryiko return libbpf_err_ptr(-ESRCH); 4456fb2426adSMartin KaFai Lau } 4457f36e99a4SAndrii Nakryiko 4458f36e99a4SAndrii Nakryiko int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ctx) 4459f36e99a4SAndrii Nakryiko { 4460f36e99a4SAndrii Nakryiko int i, n, err; 4461f36e99a4SAndrii Nakryiko 4462f36e99a4SAndrii Nakryiko switch (btf_kind(t)) { 4463f36e99a4SAndrii Nakryiko case BTF_KIND_INT: 4464f36e99a4SAndrii Nakryiko case BTF_KIND_FLOAT: 4465f36e99a4SAndrii Nakryiko case BTF_KIND_ENUM: 4466f36e99a4SAndrii Nakryiko return 0; 4467f36e99a4SAndrii Nakryiko 4468f36e99a4SAndrii Nakryiko case BTF_KIND_FWD: 4469f36e99a4SAndrii Nakryiko case BTF_KIND_CONST: 4470f36e99a4SAndrii Nakryiko case BTF_KIND_VOLATILE: 4471f36e99a4SAndrii Nakryiko case BTF_KIND_RESTRICT: 4472f36e99a4SAndrii Nakryiko case BTF_KIND_PTR: 4473f36e99a4SAndrii Nakryiko case BTF_KIND_TYPEDEF: 4474f36e99a4SAndrii Nakryiko case BTF_KIND_FUNC: 4475f36e99a4SAndrii Nakryiko case BTF_KIND_VAR: 4476f36e99a4SAndrii Nakryiko return visit(&t->type, ctx); 4477f36e99a4SAndrii Nakryiko 4478f36e99a4SAndrii Nakryiko case BTF_KIND_ARRAY: { 4479f36e99a4SAndrii Nakryiko struct btf_array *a = btf_array(t); 4480f36e99a4SAndrii Nakryiko 4481f36e99a4SAndrii Nakryiko err = visit(&a->type, ctx); 4482f36e99a4SAndrii Nakryiko err = err ?: visit(&a->index_type, ctx); 4483f36e99a4SAndrii Nakryiko return err; 4484f36e99a4SAndrii Nakryiko } 4485f36e99a4SAndrii Nakryiko 4486f36e99a4SAndrii Nakryiko case BTF_KIND_STRUCT: 4487f36e99a4SAndrii Nakryiko case BTF_KIND_UNION: { 4488f36e99a4SAndrii Nakryiko struct btf_member *m = btf_members(t); 4489f36e99a4SAndrii Nakryiko 4490f36e99a4SAndrii Nakryiko for (i = 0, n = btf_vlen(t); i < n; i++, m++) { 4491f36e99a4SAndrii Nakryiko err = visit(&m->type, ctx); 4492f36e99a4SAndrii Nakryiko if (err) 4493f36e99a4SAndrii Nakryiko return err; 4494f36e99a4SAndrii Nakryiko } 4495f36e99a4SAndrii Nakryiko return 0; 4496f36e99a4SAndrii Nakryiko } 4497f36e99a4SAndrii Nakryiko 4498f36e99a4SAndrii Nakryiko case BTF_KIND_FUNC_PROTO: { 4499f36e99a4SAndrii Nakryiko struct btf_param *m = btf_params(t); 4500f36e99a4SAndrii Nakryiko 4501f36e99a4SAndrii Nakryiko err = visit(&t->type, ctx); 4502f36e99a4SAndrii Nakryiko if (err) 4503f36e99a4SAndrii Nakryiko return err; 4504f36e99a4SAndrii Nakryiko for (i = 0, n = btf_vlen(t); i < n; i++, m++) { 4505f36e99a4SAndrii Nakryiko err = visit(&m->type, ctx); 4506f36e99a4SAndrii Nakryiko if (err) 4507f36e99a4SAndrii Nakryiko return err; 4508f36e99a4SAndrii Nakryiko } 4509f36e99a4SAndrii Nakryiko return 0; 4510f36e99a4SAndrii Nakryiko } 4511f36e99a4SAndrii Nakryiko 4512f36e99a4SAndrii Nakryiko case BTF_KIND_DATASEC: { 4513f36e99a4SAndrii Nakryiko struct btf_var_secinfo *m = btf_var_secinfos(t); 4514f36e99a4SAndrii Nakryiko 4515f36e99a4SAndrii Nakryiko for (i = 0, n = btf_vlen(t); i < n; i++, m++) { 4516f36e99a4SAndrii Nakryiko err = visit(&m->type, ctx); 4517f36e99a4SAndrii Nakryiko if (err) 4518f36e99a4SAndrii Nakryiko return err; 4519f36e99a4SAndrii Nakryiko } 4520f36e99a4SAndrii Nakryiko return 0; 4521f36e99a4SAndrii Nakryiko } 4522f36e99a4SAndrii Nakryiko 4523f36e99a4SAndrii Nakryiko default: 4524f36e99a4SAndrii Nakryiko return -EINVAL; 4525f36e99a4SAndrii Nakryiko } 4526f36e99a4SAndrii Nakryiko } 4527f36e99a4SAndrii Nakryiko 4528f36e99a4SAndrii Nakryiko int btf_type_visit_str_offs(struct btf_type *t, str_off_visit_fn visit, void *ctx) 4529f36e99a4SAndrii Nakryiko { 4530f36e99a4SAndrii Nakryiko int i, n, err; 4531f36e99a4SAndrii Nakryiko 4532f36e99a4SAndrii Nakryiko err = visit(&t->name_off, ctx); 4533f36e99a4SAndrii Nakryiko if (err) 4534f36e99a4SAndrii Nakryiko return err; 4535f36e99a4SAndrii Nakryiko 4536f36e99a4SAndrii Nakryiko switch (btf_kind(t)) { 4537f36e99a4SAndrii Nakryiko case BTF_KIND_STRUCT: 4538f36e99a4SAndrii Nakryiko case BTF_KIND_UNION: { 4539f36e99a4SAndrii Nakryiko struct btf_member *m = btf_members(t); 4540f36e99a4SAndrii Nakryiko 4541f36e99a4SAndrii Nakryiko for (i = 0, n = btf_vlen(t); i < n; i++, m++) { 4542f36e99a4SAndrii Nakryiko err = visit(&m->name_off, ctx); 4543f36e99a4SAndrii Nakryiko if (err) 4544f36e99a4SAndrii Nakryiko return err; 4545f36e99a4SAndrii Nakryiko } 4546f36e99a4SAndrii Nakryiko break; 4547f36e99a4SAndrii Nakryiko } 4548f36e99a4SAndrii Nakryiko case BTF_KIND_ENUM: { 4549f36e99a4SAndrii Nakryiko struct btf_enum *m = btf_enum(t); 4550f36e99a4SAndrii Nakryiko 4551f36e99a4SAndrii Nakryiko for (i = 0, n = btf_vlen(t); i < n; i++, m++) { 4552f36e99a4SAndrii Nakryiko err = visit(&m->name_off, ctx); 4553f36e99a4SAndrii Nakryiko if (err) 4554f36e99a4SAndrii Nakryiko return err; 4555f36e99a4SAndrii Nakryiko } 4556f36e99a4SAndrii Nakryiko break; 4557f36e99a4SAndrii Nakryiko } 4558f36e99a4SAndrii Nakryiko case BTF_KIND_FUNC_PROTO: { 4559f36e99a4SAndrii Nakryiko struct btf_param *m = btf_params(t); 4560f36e99a4SAndrii Nakryiko 4561f36e99a4SAndrii Nakryiko for (i = 0, n = btf_vlen(t); i < n; i++, m++) { 4562f36e99a4SAndrii Nakryiko err = visit(&m->name_off, ctx); 4563f36e99a4SAndrii Nakryiko if (err) 4564f36e99a4SAndrii Nakryiko return err; 4565f36e99a4SAndrii Nakryiko } 4566f36e99a4SAndrii Nakryiko break; 4567f36e99a4SAndrii Nakryiko } 4568f36e99a4SAndrii Nakryiko default: 4569f36e99a4SAndrii Nakryiko break; 4570f36e99a4SAndrii Nakryiko } 4571f36e99a4SAndrii Nakryiko 4572f36e99a4SAndrii Nakryiko return 0; 4573f36e99a4SAndrii Nakryiko } 4574f36e99a4SAndrii Nakryiko 4575f36e99a4SAndrii Nakryiko int btf_ext_visit_type_ids(struct btf_ext *btf_ext, type_id_visit_fn visit, void *ctx) 4576f36e99a4SAndrii Nakryiko { 4577f36e99a4SAndrii Nakryiko const struct btf_ext_info *seg; 4578f36e99a4SAndrii Nakryiko struct btf_ext_info_sec *sec; 4579f36e99a4SAndrii Nakryiko int i, err; 4580f36e99a4SAndrii Nakryiko 4581f36e99a4SAndrii Nakryiko seg = &btf_ext->func_info; 4582f36e99a4SAndrii Nakryiko for_each_btf_ext_sec(seg, sec) { 4583f36e99a4SAndrii Nakryiko struct bpf_func_info_min *rec; 4584f36e99a4SAndrii Nakryiko 4585f36e99a4SAndrii Nakryiko for_each_btf_ext_rec(seg, sec, i, rec) { 4586f36e99a4SAndrii Nakryiko err = visit(&rec->type_id, ctx); 4587f36e99a4SAndrii Nakryiko if (err < 0) 4588f36e99a4SAndrii Nakryiko return err; 4589f36e99a4SAndrii Nakryiko } 4590f36e99a4SAndrii Nakryiko } 4591f36e99a4SAndrii Nakryiko 4592f36e99a4SAndrii Nakryiko seg = &btf_ext->core_relo_info; 4593f36e99a4SAndrii Nakryiko for_each_btf_ext_sec(seg, sec) { 4594f36e99a4SAndrii Nakryiko struct bpf_core_relo *rec; 4595f36e99a4SAndrii Nakryiko 4596f36e99a4SAndrii Nakryiko for_each_btf_ext_rec(seg, sec, i, rec) { 4597f36e99a4SAndrii Nakryiko err = visit(&rec->type_id, ctx); 4598f36e99a4SAndrii Nakryiko if (err < 0) 4599f36e99a4SAndrii Nakryiko return err; 4600f36e99a4SAndrii Nakryiko } 4601f36e99a4SAndrii Nakryiko } 4602f36e99a4SAndrii Nakryiko 4603f36e99a4SAndrii Nakryiko return 0; 4604f36e99a4SAndrii Nakryiko } 4605f36e99a4SAndrii Nakryiko 4606f36e99a4SAndrii Nakryiko int btf_ext_visit_str_offs(struct btf_ext *btf_ext, str_off_visit_fn visit, void *ctx) 4607f36e99a4SAndrii Nakryiko { 4608f36e99a4SAndrii Nakryiko const struct btf_ext_info *seg; 4609f36e99a4SAndrii Nakryiko struct btf_ext_info_sec *sec; 4610f36e99a4SAndrii Nakryiko int i, err; 4611f36e99a4SAndrii Nakryiko 4612f36e99a4SAndrii Nakryiko seg = &btf_ext->func_info; 4613f36e99a4SAndrii Nakryiko for_each_btf_ext_sec(seg, sec) { 4614f36e99a4SAndrii Nakryiko err = visit(&sec->sec_name_off, ctx); 4615f36e99a4SAndrii Nakryiko if (err) 4616f36e99a4SAndrii Nakryiko return err; 4617f36e99a4SAndrii Nakryiko } 4618f36e99a4SAndrii Nakryiko 4619f36e99a4SAndrii Nakryiko seg = &btf_ext->line_info; 4620f36e99a4SAndrii Nakryiko for_each_btf_ext_sec(seg, sec) { 4621f36e99a4SAndrii Nakryiko struct bpf_line_info_min *rec; 4622f36e99a4SAndrii Nakryiko 4623f36e99a4SAndrii Nakryiko err = visit(&sec->sec_name_off, ctx); 4624f36e99a4SAndrii Nakryiko if (err) 4625f36e99a4SAndrii Nakryiko return err; 4626f36e99a4SAndrii Nakryiko 4627f36e99a4SAndrii Nakryiko for_each_btf_ext_rec(seg, sec, i, rec) { 4628f36e99a4SAndrii Nakryiko err = visit(&rec->file_name_off, ctx); 4629f36e99a4SAndrii Nakryiko if (err) 4630f36e99a4SAndrii Nakryiko return err; 4631f36e99a4SAndrii Nakryiko err = visit(&rec->line_off, ctx); 4632f36e99a4SAndrii Nakryiko if (err) 4633f36e99a4SAndrii Nakryiko return err; 4634f36e99a4SAndrii Nakryiko } 4635f36e99a4SAndrii Nakryiko } 4636f36e99a4SAndrii Nakryiko 4637f36e99a4SAndrii Nakryiko seg = &btf_ext->core_relo_info; 4638f36e99a4SAndrii Nakryiko for_each_btf_ext_sec(seg, sec) { 4639f36e99a4SAndrii Nakryiko struct bpf_core_relo *rec; 4640f36e99a4SAndrii Nakryiko 4641f36e99a4SAndrii Nakryiko err = visit(&sec->sec_name_off, ctx); 4642f36e99a4SAndrii Nakryiko if (err) 4643f36e99a4SAndrii Nakryiko return err; 4644f36e99a4SAndrii Nakryiko 4645f36e99a4SAndrii Nakryiko for_each_btf_ext_rec(seg, sec, i, rec) { 4646f36e99a4SAndrii Nakryiko err = visit(&rec->access_str_off, ctx); 4647f36e99a4SAndrii Nakryiko if (err) 4648f36e99a4SAndrii Nakryiko return err; 4649f36e99a4SAndrii Nakryiko } 4650f36e99a4SAndrii Nakryiko } 4651f36e99a4SAndrii Nakryiko 4652f36e99a4SAndrii Nakryiko return 0; 4653f36e99a4SAndrii Nakryiko } 4654