11bc38b8fSAlexei Starovoitov // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) 28a138aedSMartin KaFai Lau /* Copyright (c) 2018 Facebook */ 38a138aedSMartin KaFai Lau 4cdb2f920SArnaldo Carvalho de Melo #include <endian.h> 596408c43SYonghong Song #include <stdio.h> 68a138aedSMartin KaFai Lau #include <stdlib.h> 78a138aedSMartin KaFai Lau #include <string.h> 8e6c64855SAndrii Nakryiko #include <fcntl.h> 98a138aedSMartin KaFai Lau #include <unistd.h> 108a138aedSMartin KaFai Lau #include <errno.h> 11fb2426adSMartin KaFai Lau #include <sys/utsname.h> 12fb2426adSMartin KaFai Lau #include <sys/param.h> 13fb2426adSMartin KaFai Lau #include <sys/stat.h> 14fb2426adSMartin KaFai Lau #include <linux/kernel.h> 158a138aedSMartin KaFai Lau #include <linux/err.h> 168a138aedSMartin KaFai Lau #include <linux/btf.h> 17e6c64855SAndrii Nakryiko #include <gelf.h> 188a138aedSMartin KaFai Lau #include "btf.h" 198a138aedSMartin KaFai Lau #include "bpf.h" 208461ef8bSYonghong Song #include "libbpf.h" 21d72386feSAndrii Nakryiko #include "libbpf_internal.h" 222fc3fc0bSAndrii Nakryiko #include "hashmap.h" 238a138aedSMartin KaFai Lau 24fb2426adSMartin KaFai Lau #define BTF_MAX_NR_TYPES 0x7fffffffU 25fb2426adSMartin KaFai Lau #define BTF_MAX_STR_OFFSET 0x7fffffffU 268a138aedSMartin KaFai Lau 278a138aedSMartin KaFai Lau static struct btf_type btf_void; 288a138aedSMartin KaFai Lau 298a138aedSMartin KaFai Lau struct btf { 30b8604247SAndrii Nakryiko void *raw_data; 31b8604247SAndrii Nakryiko __u32 raw_size; 32b8604247SAndrii Nakryiko 33b8604247SAndrii Nakryiko /* 34b8604247SAndrii Nakryiko * When BTF is loaded from ELF or raw memory it is stored 35b8604247SAndrii Nakryiko * in contiguous memory block, pointed to by raw_data pointer, and 36b8604247SAndrii Nakryiko * hdr, types_data, and strs_data point inside that memory region to 37b8604247SAndrii Nakryiko * respective parts of BTF representation: 38b8604247SAndrii Nakryiko * 39b8604247SAndrii Nakryiko * +--------------------------------+ 40b8604247SAndrii Nakryiko * | Header | Types | Strings | 41b8604247SAndrii Nakryiko * +--------------------------------+ 42b8604247SAndrii Nakryiko * ^ ^ ^ 43b8604247SAndrii Nakryiko * | | | 44b8604247SAndrii Nakryiko * hdr | | 45b8604247SAndrii Nakryiko * types_data-+ | 46b8604247SAndrii Nakryiko * strs_data------------+ 47919d2b1dSAndrii Nakryiko * 48919d2b1dSAndrii Nakryiko * If BTF data is later modified, e.g., due to types added or 49919d2b1dSAndrii Nakryiko * removed, BTF deduplication performed, etc, this contiguous 50919d2b1dSAndrii Nakryiko * representation is broken up into three independently allocated 51919d2b1dSAndrii Nakryiko * memory regions to be able to modify them independently. 52919d2b1dSAndrii Nakryiko * raw_data is nulled out at that point, but can be later allocated 53919d2b1dSAndrii Nakryiko * and cached again if user calls btf__get_raw_data(), at which point 54919d2b1dSAndrii Nakryiko * raw_data will contain a contiguous copy of header, types, and 55919d2b1dSAndrii Nakryiko * strings: 56919d2b1dSAndrii Nakryiko * 57919d2b1dSAndrii Nakryiko * +----------+ +---------+ +-----------+ 58919d2b1dSAndrii Nakryiko * | Header | | Types | | Strings | 59919d2b1dSAndrii Nakryiko * +----------+ +---------+ +-----------+ 60919d2b1dSAndrii Nakryiko * ^ ^ ^ 61919d2b1dSAndrii Nakryiko * | | | 62919d2b1dSAndrii Nakryiko * hdr | | 63919d2b1dSAndrii Nakryiko * types_data----+ | 64919d2b1dSAndrii Nakryiko * strs_data------------------+ 65919d2b1dSAndrii Nakryiko * 66919d2b1dSAndrii Nakryiko * +----------+---------+-----------+ 67919d2b1dSAndrii Nakryiko * | Header | Types | Strings | 68919d2b1dSAndrii Nakryiko * raw_data----->+----------+---------+-----------+ 69b8604247SAndrii Nakryiko */ 708a138aedSMartin KaFai Lau struct btf_header *hdr; 71919d2b1dSAndrii Nakryiko 72b8604247SAndrii Nakryiko void *types_data; 73919d2b1dSAndrii Nakryiko size_t types_data_cap; /* used size stored in hdr->type_len */ 74b8604247SAndrii Nakryiko 75b8604247SAndrii Nakryiko /* type ID to `struct btf_type *` lookup index */ 76740e69c3SAndrii Nakryiko __u32 *type_offs; 77192f5a1fSAndrii Nakryiko size_t type_offs_cap; 785b891af7SMartin KaFai Lau __u32 nr_types; 79b8604247SAndrii Nakryiko 80919d2b1dSAndrii Nakryiko void *strs_data; 81919d2b1dSAndrii Nakryiko size_t strs_data_cap; /* used size stored in hdr->str_len */ 82919d2b1dSAndrii Nakryiko 83919d2b1dSAndrii Nakryiko /* lookup index for each unique string in strings section */ 84919d2b1dSAndrii Nakryiko struct hashmap *strs_hash; 85919d2b1dSAndrii Nakryiko /* whether strings are already deduplicated */ 86919d2b1dSAndrii Nakryiko bool strs_deduped; 87b8604247SAndrii Nakryiko /* BTF object FD, if loaded into kernel */ 888a138aedSMartin KaFai Lau int fd; 89b8604247SAndrii Nakryiko 90b8604247SAndrii Nakryiko /* Pointer size (in bytes) for a target architecture of this BTF */ 9144ad23dfSAndrii Nakryiko int ptr_sz; 928a138aedSMartin KaFai Lau }; 938a138aedSMartin KaFai Lau 94d7f5b5e0SYonghong Song static inline __u64 ptr_to_u64(const void *ptr) 95d7f5b5e0SYonghong Song { 96d7f5b5e0SYonghong Song return (__u64) (unsigned long) ptr; 97d7f5b5e0SYonghong Song } 98d7f5b5e0SYonghong Song 99192f5a1fSAndrii Nakryiko /* Ensure given dynamically allocated memory region pointed to by *data* with 100192f5a1fSAndrii Nakryiko * capacity of *cap_cnt* elements each taking *elem_sz* bytes has enough 101192f5a1fSAndrii Nakryiko * memory to accomodate *add_cnt* new elements, assuming *cur_cnt* elements 102192f5a1fSAndrii Nakryiko * are already used. At most *max_cnt* elements can be ever allocated. 103192f5a1fSAndrii Nakryiko * If necessary, memory is reallocated and all existing data is copied over, 104192f5a1fSAndrii Nakryiko * new pointer to the memory region is stored at *data, new memory region 105192f5a1fSAndrii Nakryiko * capacity (in number of elements) is stored in *cap. 106192f5a1fSAndrii Nakryiko * On success, memory pointer to the beginning of unused memory is returned. 107192f5a1fSAndrii Nakryiko * On error, NULL is returned. 108192f5a1fSAndrii Nakryiko */ 109192f5a1fSAndrii Nakryiko void *btf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz, 110192f5a1fSAndrii Nakryiko size_t cur_cnt, size_t max_cnt, size_t add_cnt) 1118a138aedSMartin KaFai Lau { 112192f5a1fSAndrii Nakryiko size_t new_cnt; 113192f5a1fSAndrii Nakryiko void *new_data; 1148a138aedSMartin KaFai Lau 115192f5a1fSAndrii Nakryiko if (cur_cnt + add_cnt <= *cap_cnt) 116192f5a1fSAndrii Nakryiko return *data + cur_cnt * elem_sz; 1178a138aedSMartin KaFai Lau 118192f5a1fSAndrii Nakryiko /* requested more than the set limit */ 119192f5a1fSAndrii Nakryiko if (cur_cnt + add_cnt > max_cnt) 120192f5a1fSAndrii Nakryiko return NULL; 1218a138aedSMartin KaFai Lau 122192f5a1fSAndrii Nakryiko new_cnt = *cap_cnt; 123192f5a1fSAndrii Nakryiko new_cnt += new_cnt / 4; /* expand by 25% */ 124192f5a1fSAndrii Nakryiko if (new_cnt < 16) /* but at least 16 elements */ 125192f5a1fSAndrii Nakryiko new_cnt = 16; 126192f5a1fSAndrii Nakryiko if (new_cnt > max_cnt) /* but not exceeding a set limit */ 127192f5a1fSAndrii Nakryiko new_cnt = max_cnt; 128192f5a1fSAndrii Nakryiko if (new_cnt < cur_cnt + add_cnt) /* also ensure we have enough memory */ 129192f5a1fSAndrii Nakryiko new_cnt = cur_cnt + add_cnt; 1308a138aedSMartin KaFai Lau 131192f5a1fSAndrii Nakryiko new_data = libbpf_reallocarray(*data, new_cnt, elem_sz); 132192f5a1fSAndrii Nakryiko if (!new_data) 133192f5a1fSAndrii Nakryiko return NULL; 1348a138aedSMartin KaFai Lau 135192f5a1fSAndrii Nakryiko /* zero out newly allocated portion of memory */ 136192f5a1fSAndrii Nakryiko memset(new_data + (*cap_cnt) * elem_sz, 0, (new_cnt - *cap_cnt) * elem_sz); 137192f5a1fSAndrii Nakryiko 138192f5a1fSAndrii Nakryiko *data = new_data; 139192f5a1fSAndrii Nakryiko *cap_cnt = new_cnt; 140192f5a1fSAndrii Nakryiko return new_data + cur_cnt * elem_sz; 1418a138aedSMartin KaFai Lau } 1428a138aedSMartin KaFai Lau 143192f5a1fSAndrii Nakryiko static int btf_add_type_idx_entry(struct btf *btf, __u32 type_off) 144192f5a1fSAndrii Nakryiko { 145192f5a1fSAndrii Nakryiko __u32 *p; 1468a138aedSMartin KaFai Lau 147192f5a1fSAndrii Nakryiko p = btf_add_mem((void **)&btf->type_offs, &btf->type_offs_cap, sizeof(__u32), 148192f5a1fSAndrii Nakryiko btf->nr_types + 1, BTF_MAX_NR_TYPES, 1); 149192f5a1fSAndrii Nakryiko if (!p) 150192f5a1fSAndrii Nakryiko return -ENOMEM; 151192f5a1fSAndrii Nakryiko 152192f5a1fSAndrii Nakryiko *p = type_off; 1538a138aedSMartin KaFai Lau return 0; 1548a138aedSMartin KaFai Lau } 1558a138aedSMartin KaFai Lau 1568461ef8bSYonghong Song static int btf_parse_hdr(struct btf *btf) 1578a138aedSMartin KaFai Lau { 1588a138aedSMartin KaFai Lau const struct btf_header *hdr = btf->hdr; 1595b891af7SMartin KaFai Lau __u32 meta_left; 1608a138aedSMartin KaFai Lau 161b8604247SAndrii Nakryiko if (btf->raw_size < sizeof(struct btf_header)) { 1628461ef8bSYonghong Song pr_debug("BTF header not found\n"); 1638a138aedSMartin KaFai Lau return -EINVAL; 1648a138aedSMartin KaFai Lau } 1658a138aedSMartin KaFai Lau 1668a138aedSMartin KaFai Lau if (hdr->magic != BTF_MAGIC) { 1678461ef8bSYonghong Song pr_debug("Invalid BTF magic:%x\n", hdr->magic); 1688a138aedSMartin KaFai Lau return -EINVAL; 1698a138aedSMartin KaFai Lau } 1708a138aedSMartin KaFai Lau 1718a138aedSMartin KaFai Lau if (hdr->version != BTF_VERSION) { 1728461ef8bSYonghong Song pr_debug("Unsupported BTF version:%u\n", hdr->version); 1738a138aedSMartin KaFai Lau return -ENOTSUP; 1748a138aedSMartin KaFai Lau } 1758a138aedSMartin KaFai Lau 1768a138aedSMartin KaFai Lau if (hdr->flags) { 1778461ef8bSYonghong Song pr_debug("Unsupported BTF flags:%x\n", hdr->flags); 1788a138aedSMartin KaFai Lau return -ENOTSUP; 1798a138aedSMartin KaFai Lau } 1808a138aedSMartin KaFai Lau 181b8604247SAndrii Nakryiko meta_left = btf->raw_size - sizeof(*hdr); 1828a138aedSMartin KaFai Lau if (!meta_left) { 1838461ef8bSYonghong Song pr_debug("BTF has no data\n"); 1848a138aedSMartin KaFai Lau return -EINVAL; 1858a138aedSMartin KaFai Lau } 1868a138aedSMartin KaFai Lau 1878a138aedSMartin KaFai Lau if (meta_left < hdr->type_off) { 1888461ef8bSYonghong Song pr_debug("Invalid BTF type section offset:%u\n", hdr->type_off); 1898a138aedSMartin KaFai Lau return -EINVAL; 1908a138aedSMartin KaFai Lau } 1918a138aedSMartin KaFai Lau 1928a138aedSMartin KaFai Lau if (meta_left < hdr->str_off) { 1938461ef8bSYonghong Song pr_debug("Invalid BTF string section offset:%u\n", hdr->str_off); 1948a138aedSMartin KaFai Lau return -EINVAL; 1958a138aedSMartin KaFai Lau } 1968a138aedSMartin KaFai Lau 1978a138aedSMartin KaFai Lau if (hdr->type_off >= hdr->str_off) { 1988461ef8bSYonghong Song pr_debug("BTF type section offset >= string section offset. No type?\n"); 1998a138aedSMartin KaFai Lau return -EINVAL; 2008a138aedSMartin KaFai Lau } 2018a138aedSMartin KaFai Lau 2028a138aedSMartin KaFai Lau if (hdr->type_off & 0x02) { 2038461ef8bSYonghong Song pr_debug("BTF type section is not aligned to 4 bytes\n"); 2048a138aedSMartin KaFai Lau return -EINVAL; 2058a138aedSMartin KaFai Lau } 2068a138aedSMartin KaFai Lau 2078a138aedSMartin KaFai Lau return 0; 2088a138aedSMartin KaFai Lau } 2098a138aedSMartin KaFai Lau 2108461ef8bSYonghong Song static int btf_parse_str_sec(struct btf *btf) 2118a138aedSMartin KaFai Lau { 2128a138aedSMartin KaFai Lau const struct btf_header *hdr = btf->hdr; 213b8604247SAndrii Nakryiko const char *start = btf->strs_data; 2148a138aedSMartin KaFai Lau const char *end = start + btf->hdr->str_len; 2158a138aedSMartin KaFai Lau 2165aab392cSAndrii Nakryiko if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_STR_OFFSET || 2178a138aedSMartin KaFai Lau start[0] || end[-1]) { 2188461ef8bSYonghong Song pr_debug("Invalid BTF string section\n"); 2198a138aedSMartin KaFai Lau return -EINVAL; 2208a138aedSMartin KaFai Lau } 2218a138aedSMartin KaFai Lau 2228a138aedSMartin KaFai Lau return 0; 2238a138aedSMartin KaFai Lau } 2248a138aedSMartin KaFai Lau 225740e69c3SAndrii Nakryiko static int btf_type_size(const struct btf_type *t) 22669eaab04SAndrii Nakryiko { 22769eaab04SAndrii Nakryiko int base_size = sizeof(struct btf_type); 228b03bc685SAndrii Nakryiko __u16 vlen = btf_vlen(t); 22969eaab04SAndrii Nakryiko 230b03bc685SAndrii Nakryiko switch (btf_kind(t)) { 23169eaab04SAndrii Nakryiko case BTF_KIND_FWD: 23269eaab04SAndrii Nakryiko case BTF_KIND_CONST: 23369eaab04SAndrii Nakryiko case BTF_KIND_VOLATILE: 23469eaab04SAndrii Nakryiko case BTF_KIND_RESTRICT: 23569eaab04SAndrii Nakryiko case BTF_KIND_PTR: 23669eaab04SAndrii Nakryiko case BTF_KIND_TYPEDEF: 23769eaab04SAndrii Nakryiko case BTF_KIND_FUNC: 23869eaab04SAndrii Nakryiko return base_size; 23969eaab04SAndrii Nakryiko case BTF_KIND_INT: 24069eaab04SAndrii Nakryiko return base_size + sizeof(__u32); 24169eaab04SAndrii Nakryiko case BTF_KIND_ENUM: 24269eaab04SAndrii Nakryiko return base_size + vlen * sizeof(struct btf_enum); 24369eaab04SAndrii Nakryiko case BTF_KIND_ARRAY: 24469eaab04SAndrii Nakryiko return base_size + sizeof(struct btf_array); 24569eaab04SAndrii Nakryiko case BTF_KIND_STRUCT: 24669eaab04SAndrii Nakryiko case BTF_KIND_UNION: 24769eaab04SAndrii Nakryiko return base_size + vlen * sizeof(struct btf_member); 24869eaab04SAndrii Nakryiko case BTF_KIND_FUNC_PROTO: 24969eaab04SAndrii Nakryiko return base_size + vlen * sizeof(struct btf_param); 2501713d68bSDaniel Borkmann case BTF_KIND_VAR: 2511713d68bSDaniel Borkmann return base_size + sizeof(struct btf_var); 2521713d68bSDaniel Borkmann case BTF_KIND_DATASEC: 2531713d68bSDaniel Borkmann return base_size + vlen * sizeof(struct btf_var_secinfo); 25469eaab04SAndrii Nakryiko default: 255b03bc685SAndrii Nakryiko pr_debug("Unsupported BTF_KIND:%u\n", btf_kind(t)); 25669eaab04SAndrii Nakryiko return -EINVAL; 25769eaab04SAndrii Nakryiko } 25869eaab04SAndrii Nakryiko } 25969eaab04SAndrii Nakryiko 2608461ef8bSYonghong Song static int btf_parse_type_sec(struct btf *btf) 2618a138aedSMartin KaFai Lau { 2628a138aedSMartin KaFai Lau struct btf_header *hdr = btf->hdr; 263b8604247SAndrii Nakryiko void *next_type = btf->types_data; 264740e69c3SAndrii Nakryiko void *end_type = next_type + hdr->type_len; 265192f5a1fSAndrii Nakryiko int err, type_size; 266192f5a1fSAndrii Nakryiko 267192f5a1fSAndrii Nakryiko /* VOID (type_id == 0) is specially handled by btf__get_type_by_id(), 268192f5a1fSAndrii Nakryiko * so ensure we can never properly use its offset from index by 269192f5a1fSAndrii Nakryiko * setting it to a large value 270192f5a1fSAndrii Nakryiko */ 271192f5a1fSAndrii Nakryiko err = btf_add_type_idx_entry(btf, UINT_MAX); 272192f5a1fSAndrii Nakryiko if (err) 273192f5a1fSAndrii Nakryiko return err; 274740e69c3SAndrii Nakryiko 2758a138aedSMartin KaFai Lau while (next_type < end_type) { 276740e69c3SAndrii Nakryiko err = btf_add_type_idx_entry(btf, next_type - btf->types_data); 2778a138aedSMartin KaFai Lau if (err) 2788a138aedSMartin KaFai Lau return err; 279740e69c3SAndrii Nakryiko 280740e69c3SAndrii Nakryiko type_size = btf_type_size(next_type); 281740e69c3SAndrii Nakryiko if (type_size < 0) 282740e69c3SAndrii Nakryiko return type_size; 283740e69c3SAndrii Nakryiko 284740e69c3SAndrii Nakryiko next_type += type_size; 285740e69c3SAndrii Nakryiko btf->nr_types++; 2868a138aedSMartin KaFai Lau } 2878a138aedSMartin KaFai Lau 2888a138aedSMartin KaFai Lau return 0; 2898a138aedSMartin KaFai Lau } 2908a138aedSMartin KaFai Lau 2919c651127SAndrii Nakryiko __u32 btf__get_nr_types(const struct btf *btf) 2929c651127SAndrii Nakryiko { 2939c651127SAndrii Nakryiko return btf->nr_types; 2949c651127SAndrii Nakryiko } 2959c651127SAndrii Nakryiko 296740e69c3SAndrii Nakryiko /* internal helper returning non-const pointer to a type */ 297740e69c3SAndrii Nakryiko static struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id) 298740e69c3SAndrii Nakryiko { 299740e69c3SAndrii Nakryiko if (type_id == 0) 300740e69c3SAndrii Nakryiko return &btf_void; 301740e69c3SAndrii Nakryiko 302740e69c3SAndrii Nakryiko return btf->types_data + btf->type_offs[type_id]; 303740e69c3SAndrii Nakryiko } 304740e69c3SAndrii Nakryiko 30538d5d3b3SMartin KaFai Lau const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id) 3068a138aedSMartin KaFai Lau { 3078a138aedSMartin KaFai Lau if (type_id > btf->nr_types) 3088a138aedSMartin KaFai Lau return NULL; 309740e69c3SAndrii Nakryiko return btf_type_by_id((struct btf *)btf, type_id); 3108a138aedSMartin KaFai Lau } 3118a138aedSMartin KaFai Lau 31244ad23dfSAndrii Nakryiko static int determine_ptr_size(const struct btf *btf) 31344ad23dfSAndrii Nakryiko { 31444ad23dfSAndrii Nakryiko const struct btf_type *t; 31544ad23dfSAndrii Nakryiko const char *name; 31644ad23dfSAndrii Nakryiko int i; 31744ad23dfSAndrii Nakryiko 31844ad23dfSAndrii Nakryiko for (i = 1; i <= btf->nr_types; i++) { 31944ad23dfSAndrii Nakryiko t = btf__type_by_id(btf, i); 32044ad23dfSAndrii Nakryiko if (!btf_is_int(t)) 32144ad23dfSAndrii Nakryiko continue; 32244ad23dfSAndrii Nakryiko 32344ad23dfSAndrii Nakryiko name = btf__name_by_offset(btf, t->name_off); 32444ad23dfSAndrii Nakryiko if (!name) 32544ad23dfSAndrii Nakryiko continue; 32644ad23dfSAndrii Nakryiko 32744ad23dfSAndrii Nakryiko if (strcmp(name, "long int") == 0 || 32844ad23dfSAndrii Nakryiko strcmp(name, "long unsigned int") == 0) { 32944ad23dfSAndrii Nakryiko if (t->size != 4 && t->size != 8) 33044ad23dfSAndrii Nakryiko continue; 33144ad23dfSAndrii Nakryiko return t->size; 33244ad23dfSAndrii Nakryiko } 33344ad23dfSAndrii Nakryiko } 33444ad23dfSAndrii Nakryiko 33544ad23dfSAndrii Nakryiko return -1; 33644ad23dfSAndrii Nakryiko } 33744ad23dfSAndrii Nakryiko 33844ad23dfSAndrii Nakryiko static size_t btf_ptr_sz(const struct btf *btf) 33944ad23dfSAndrii Nakryiko { 34044ad23dfSAndrii Nakryiko if (!btf->ptr_sz) 34144ad23dfSAndrii Nakryiko ((struct btf *)btf)->ptr_sz = determine_ptr_size(btf); 34244ad23dfSAndrii Nakryiko return btf->ptr_sz < 0 ? sizeof(void *) : btf->ptr_sz; 34344ad23dfSAndrii Nakryiko } 34444ad23dfSAndrii Nakryiko 34544ad23dfSAndrii Nakryiko /* Return pointer size this BTF instance assumes. The size is heuristically 34644ad23dfSAndrii Nakryiko * determined by looking for 'long' or 'unsigned long' integer type and 34744ad23dfSAndrii Nakryiko * recording its size in bytes. If BTF type information doesn't have any such 34844ad23dfSAndrii Nakryiko * type, this function returns 0. In the latter case, native architecture's 34944ad23dfSAndrii Nakryiko * pointer size is assumed, so will be either 4 or 8, depending on 35044ad23dfSAndrii Nakryiko * architecture that libbpf was compiled for. It's possible to override 35144ad23dfSAndrii Nakryiko * guessed value by using btf__set_pointer_size() API. 35244ad23dfSAndrii Nakryiko */ 35344ad23dfSAndrii Nakryiko size_t btf__pointer_size(const struct btf *btf) 35444ad23dfSAndrii Nakryiko { 35544ad23dfSAndrii Nakryiko if (!btf->ptr_sz) 35644ad23dfSAndrii Nakryiko ((struct btf *)btf)->ptr_sz = determine_ptr_size(btf); 35744ad23dfSAndrii Nakryiko 35844ad23dfSAndrii Nakryiko if (btf->ptr_sz < 0) 35944ad23dfSAndrii Nakryiko /* not enough BTF type info to guess */ 36044ad23dfSAndrii Nakryiko return 0; 36144ad23dfSAndrii Nakryiko 36244ad23dfSAndrii Nakryiko return btf->ptr_sz; 36344ad23dfSAndrii Nakryiko } 36444ad23dfSAndrii Nakryiko 36544ad23dfSAndrii Nakryiko /* Override or set pointer size in bytes. Only values of 4 and 8 are 36644ad23dfSAndrii Nakryiko * supported. 36744ad23dfSAndrii Nakryiko */ 36844ad23dfSAndrii Nakryiko int btf__set_pointer_size(struct btf *btf, size_t ptr_sz) 36944ad23dfSAndrii Nakryiko { 37044ad23dfSAndrii Nakryiko if (ptr_sz != 4 && ptr_sz != 8) 37144ad23dfSAndrii Nakryiko return -EINVAL; 37244ad23dfSAndrii Nakryiko btf->ptr_sz = ptr_sz; 37344ad23dfSAndrii Nakryiko return 0; 37444ad23dfSAndrii Nakryiko } 37544ad23dfSAndrii Nakryiko 3768a138aedSMartin KaFai Lau static bool btf_type_is_void(const struct btf_type *t) 3778a138aedSMartin KaFai Lau { 378b03bc685SAndrii Nakryiko return t == &btf_void || btf_is_fwd(t); 3798a138aedSMartin KaFai Lau } 3808a138aedSMartin KaFai Lau 3818a138aedSMartin KaFai Lau static bool btf_type_is_void_or_null(const struct btf_type *t) 3828a138aedSMartin KaFai Lau { 3838a138aedSMartin KaFai Lau return !t || btf_type_is_void(t); 3848a138aedSMartin KaFai Lau } 3858a138aedSMartin KaFai Lau 3868a138aedSMartin KaFai Lau #define MAX_RESOLVE_DEPTH 32 3878a138aedSMartin KaFai Lau 3885b891af7SMartin KaFai Lau __s64 btf__resolve_size(const struct btf *btf, __u32 type_id) 3898a138aedSMartin KaFai Lau { 3908a138aedSMartin KaFai Lau const struct btf_array *array; 3918a138aedSMartin KaFai Lau const struct btf_type *t; 3925b891af7SMartin KaFai Lau __u32 nelems = 1; 3935b891af7SMartin KaFai Lau __s64 size = -1; 3948a138aedSMartin KaFai Lau int i; 3958a138aedSMartin KaFai Lau 39692b57121SOkash Khawaja t = btf__type_by_id(btf, type_id); 3978a138aedSMartin KaFai Lau for (i = 0; i < MAX_RESOLVE_DEPTH && !btf_type_is_void_or_null(t); 3988a138aedSMartin KaFai Lau i++) { 399b03bc685SAndrii Nakryiko switch (btf_kind(t)) { 40069eaab04SAndrii Nakryiko case BTF_KIND_INT: 40169eaab04SAndrii Nakryiko case BTF_KIND_STRUCT: 40269eaab04SAndrii Nakryiko case BTF_KIND_UNION: 40369eaab04SAndrii Nakryiko case BTF_KIND_ENUM: 4041713d68bSDaniel Borkmann case BTF_KIND_DATASEC: 40569eaab04SAndrii Nakryiko size = t->size; 40669eaab04SAndrii Nakryiko goto done; 40769eaab04SAndrii Nakryiko case BTF_KIND_PTR: 40844ad23dfSAndrii Nakryiko size = btf_ptr_sz(btf); 40969eaab04SAndrii Nakryiko goto done; 4108a138aedSMartin KaFai Lau case BTF_KIND_TYPEDEF: 4118a138aedSMartin KaFai Lau case BTF_KIND_VOLATILE: 4128a138aedSMartin KaFai Lau case BTF_KIND_CONST: 4138a138aedSMartin KaFai Lau case BTF_KIND_RESTRICT: 4141713d68bSDaniel Borkmann case BTF_KIND_VAR: 4158a138aedSMartin KaFai Lau type_id = t->type; 4168a138aedSMartin KaFai Lau break; 4178a138aedSMartin KaFai Lau case BTF_KIND_ARRAY: 418b03bc685SAndrii Nakryiko array = btf_array(t); 4198a138aedSMartin KaFai Lau if (nelems && array->nelems > UINT32_MAX / nelems) 4208a138aedSMartin KaFai Lau return -E2BIG; 4218a138aedSMartin KaFai Lau nelems *= array->nelems; 4228a138aedSMartin KaFai Lau type_id = array->type; 4238a138aedSMartin KaFai Lau break; 4248a138aedSMartin KaFai Lau default: 4258a138aedSMartin KaFai Lau return -EINVAL; 4268a138aedSMartin KaFai Lau } 4278a138aedSMartin KaFai Lau 42892b57121SOkash Khawaja t = btf__type_by_id(btf, type_id); 4298a138aedSMartin KaFai Lau } 4308a138aedSMartin KaFai Lau 431994021a7SAndrii Nakryiko done: 4328a138aedSMartin KaFai Lau if (size < 0) 4338a138aedSMartin KaFai Lau return -EINVAL; 4348a138aedSMartin KaFai Lau if (nelems && size > UINT32_MAX / nelems) 4358a138aedSMartin KaFai Lau return -E2BIG; 4368a138aedSMartin KaFai Lau 4378a138aedSMartin KaFai Lau return nelems * size; 4388a138aedSMartin KaFai Lau } 4398a138aedSMartin KaFai Lau 4403d208f4cSAndrii Nakryiko int btf__align_of(const struct btf *btf, __u32 id) 4413d208f4cSAndrii Nakryiko { 4423d208f4cSAndrii Nakryiko const struct btf_type *t = btf__type_by_id(btf, id); 4433d208f4cSAndrii Nakryiko __u16 kind = btf_kind(t); 4443d208f4cSAndrii Nakryiko 4453d208f4cSAndrii Nakryiko switch (kind) { 4463d208f4cSAndrii Nakryiko case BTF_KIND_INT: 4473d208f4cSAndrii Nakryiko case BTF_KIND_ENUM: 44844ad23dfSAndrii Nakryiko return min(btf_ptr_sz(btf), (size_t)t->size); 4493d208f4cSAndrii Nakryiko case BTF_KIND_PTR: 45044ad23dfSAndrii Nakryiko return btf_ptr_sz(btf); 4513d208f4cSAndrii Nakryiko case BTF_KIND_TYPEDEF: 4523d208f4cSAndrii Nakryiko case BTF_KIND_VOLATILE: 4533d208f4cSAndrii Nakryiko case BTF_KIND_CONST: 4543d208f4cSAndrii Nakryiko case BTF_KIND_RESTRICT: 4553d208f4cSAndrii Nakryiko return btf__align_of(btf, t->type); 4563d208f4cSAndrii Nakryiko case BTF_KIND_ARRAY: 4573d208f4cSAndrii Nakryiko return btf__align_of(btf, btf_array(t)->type); 4583d208f4cSAndrii Nakryiko case BTF_KIND_STRUCT: 4593d208f4cSAndrii Nakryiko case BTF_KIND_UNION: { 4603d208f4cSAndrii Nakryiko const struct btf_member *m = btf_members(t); 4613d208f4cSAndrii Nakryiko __u16 vlen = btf_vlen(t); 462a79ac2d1SPrashant Bhole int i, max_align = 1, align; 4633d208f4cSAndrii Nakryiko 4643d208f4cSAndrii Nakryiko for (i = 0; i < vlen; i++, m++) { 465a79ac2d1SPrashant Bhole align = btf__align_of(btf, m->type); 466a79ac2d1SPrashant Bhole if (align <= 0) 467a79ac2d1SPrashant Bhole return align; 468a79ac2d1SPrashant Bhole max_align = max(max_align, align); 4693d208f4cSAndrii Nakryiko } 4703d208f4cSAndrii Nakryiko 471a79ac2d1SPrashant Bhole return max_align; 4723d208f4cSAndrii Nakryiko } 4733d208f4cSAndrii Nakryiko default: 4743d208f4cSAndrii Nakryiko pr_warn("unsupported BTF_KIND:%u\n", btf_kind(t)); 4753d208f4cSAndrii Nakryiko return 0; 4763d208f4cSAndrii Nakryiko } 4773d208f4cSAndrii Nakryiko } 4783d208f4cSAndrii Nakryiko 47992b57121SOkash Khawaja int btf__resolve_type(const struct btf *btf, __u32 type_id) 48092b57121SOkash Khawaja { 48192b57121SOkash Khawaja const struct btf_type *t; 48292b57121SOkash Khawaja int depth = 0; 48392b57121SOkash Khawaja 48492b57121SOkash Khawaja t = btf__type_by_id(btf, type_id); 48592b57121SOkash Khawaja while (depth < MAX_RESOLVE_DEPTH && 48692b57121SOkash Khawaja !btf_type_is_void_or_null(t) && 487b03bc685SAndrii Nakryiko (btf_is_mod(t) || btf_is_typedef(t) || btf_is_var(t))) { 48892b57121SOkash Khawaja type_id = t->type; 48992b57121SOkash Khawaja t = btf__type_by_id(btf, type_id); 49092b57121SOkash Khawaja depth++; 49192b57121SOkash Khawaja } 49292b57121SOkash Khawaja 49392b57121SOkash Khawaja if (depth == MAX_RESOLVE_DEPTH || btf_type_is_void_or_null(t)) 49492b57121SOkash Khawaja return -EINVAL; 49592b57121SOkash Khawaja 49692b57121SOkash Khawaja return type_id; 49792b57121SOkash Khawaja } 49892b57121SOkash Khawaja 4995b891af7SMartin KaFai Lau __s32 btf__find_by_name(const struct btf *btf, const char *type_name) 5008a138aedSMartin KaFai Lau { 5015b891af7SMartin KaFai Lau __u32 i; 5028a138aedSMartin KaFai Lau 5038a138aedSMartin KaFai Lau if (!strcmp(type_name, "void")) 5048a138aedSMartin KaFai Lau return 0; 5058a138aedSMartin KaFai Lau 5068a138aedSMartin KaFai Lau for (i = 1; i <= btf->nr_types; i++) { 507740e69c3SAndrii Nakryiko const struct btf_type *t = btf__type_by_id(btf, i); 50892b57121SOkash Khawaja const char *name = btf__name_by_offset(btf, t->name_off); 5098a138aedSMartin KaFai Lau 5108a138aedSMartin KaFai Lau if (name && !strcmp(type_name, name)) 5118a138aedSMartin KaFai Lau return i; 5128a138aedSMartin KaFai Lau } 5138a138aedSMartin KaFai Lau 5148a138aedSMartin KaFai Lau return -ENOENT; 5158a138aedSMartin KaFai Lau } 5168a138aedSMartin KaFai Lau 5171442e287SAlexei Starovoitov __s32 btf__find_by_name_kind(const struct btf *btf, const char *type_name, 5181442e287SAlexei Starovoitov __u32 kind) 5191442e287SAlexei Starovoitov { 5201442e287SAlexei Starovoitov __u32 i; 5211442e287SAlexei Starovoitov 5221442e287SAlexei Starovoitov if (kind == BTF_KIND_UNKN || !strcmp(type_name, "void")) 5231442e287SAlexei Starovoitov return 0; 5241442e287SAlexei Starovoitov 5251442e287SAlexei Starovoitov for (i = 1; i <= btf->nr_types; i++) { 526740e69c3SAndrii Nakryiko const struct btf_type *t = btf__type_by_id(btf, i); 5271442e287SAlexei Starovoitov const char *name; 5281442e287SAlexei Starovoitov 5291442e287SAlexei Starovoitov if (btf_kind(t) != kind) 5301442e287SAlexei Starovoitov continue; 5311442e287SAlexei Starovoitov name = btf__name_by_offset(btf, t->name_off); 5321442e287SAlexei Starovoitov if (name && !strcmp(type_name, name)) 5331442e287SAlexei Starovoitov return i; 5341442e287SAlexei Starovoitov } 5351442e287SAlexei Starovoitov 5361442e287SAlexei Starovoitov return -ENOENT; 5371442e287SAlexei Starovoitov } 5381442e287SAlexei Starovoitov 539919d2b1dSAndrii Nakryiko static bool btf_is_modifiable(const struct btf *btf) 540919d2b1dSAndrii Nakryiko { 541919d2b1dSAndrii Nakryiko return (void *)btf->hdr != btf->raw_data; 542919d2b1dSAndrii Nakryiko } 543919d2b1dSAndrii Nakryiko 5448a138aedSMartin KaFai Lau void btf__free(struct btf *btf) 5458a138aedSMartin KaFai Lau { 54650450fc7SAndrii Nakryiko if (IS_ERR_OR_NULL(btf)) 5478a138aedSMartin KaFai Lau return; 5488a138aedSMartin KaFai Lau 54981372e12SAndrii Nakryiko if (btf->fd >= 0) 5508a138aedSMartin KaFai Lau close(btf->fd); 5518a138aedSMartin KaFai Lau 552919d2b1dSAndrii Nakryiko if (btf_is_modifiable(btf)) { 553919d2b1dSAndrii Nakryiko /* if BTF was modified after loading, it will have a split 554919d2b1dSAndrii Nakryiko * in-memory representation for header, types, and strings 555919d2b1dSAndrii Nakryiko * sections, so we need to free all of them individually. It 556919d2b1dSAndrii Nakryiko * might still have a cached contiguous raw data present, 557919d2b1dSAndrii Nakryiko * which will be unconditionally freed below. 558919d2b1dSAndrii Nakryiko */ 559919d2b1dSAndrii Nakryiko free(btf->hdr); 560919d2b1dSAndrii Nakryiko free(btf->types_data); 561919d2b1dSAndrii Nakryiko free(btf->strs_data); 562919d2b1dSAndrii Nakryiko } 563b8604247SAndrii Nakryiko free(btf->raw_data); 564740e69c3SAndrii Nakryiko free(btf->type_offs); 5658a138aedSMartin KaFai Lau free(btf); 5668a138aedSMartin KaFai Lau } 5678a138aedSMartin KaFai Lau 568a871b043SAndrii Nakryiko struct btf *btf__new_empty(void) 569a871b043SAndrii Nakryiko { 570a871b043SAndrii Nakryiko struct btf *btf; 571a871b043SAndrii Nakryiko 572a871b043SAndrii Nakryiko btf = calloc(1, sizeof(*btf)); 573a871b043SAndrii Nakryiko if (!btf) 574a871b043SAndrii Nakryiko return ERR_PTR(-ENOMEM); 575a871b043SAndrii Nakryiko btf->fd = -1; 576a871b043SAndrii Nakryiko btf->ptr_sz = sizeof(void *); 577a871b043SAndrii Nakryiko 578a871b043SAndrii Nakryiko /* +1 for empty string at offset 0 */ 579a871b043SAndrii Nakryiko btf->raw_size = sizeof(struct btf_header) + 1; 580a871b043SAndrii Nakryiko btf->raw_data = calloc(1, btf->raw_size); 581a871b043SAndrii Nakryiko if (!btf->raw_data) { 582a871b043SAndrii Nakryiko free(btf); 583a871b043SAndrii Nakryiko return ERR_PTR(-ENOMEM); 584a871b043SAndrii Nakryiko } 585a871b043SAndrii Nakryiko 586a871b043SAndrii Nakryiko btf->hdr = btf->raw_data; 587a871b043SAndrii Nakryiko btf->hdr->hdr_len = sizeof(struct btf_header); 588a871b043SAndrii Nakryiko btf->hdr->magic = BTF_MAGIC; 589a871b043SAndrii Nakryiko btf->hdr->version = BTF_VERSION; 590a871b043SAndrii Nakryiko 591a871b043SAndrii Nakryiko btf->types_data = btf->raw_data + btf->hdr->hdr_len; 592a871b043SAndrii Nakryiko btf->strs_data = btf->raw_data + btf->hdr->hdr_len; 593a871b043SAndrii Nakryiko btf->hdr->str_len = 1; /* empty string at offset 0 */ 594a871b043SAndrii Nakryiko 595a871b043SAndrii Nakryiko return btf; 596a871b043SAndrii Nakryiko } 597a871b043SAndrii Nakryiko 5985c3320d7SAndrii Nakryiko struct btf *btf__new(const void *data, __u32 size) 5998a138aedSMartin KaFai Lau { 6008a138aedSMartin KaFai Lau struct btf *btf; 6018a138aedSMartin KaFai Lau int err; 6028a138aedSMartin KaFai Lau 6038a138aedSMartin KaFai Lau btf = calloc(1, sizeof(struct btf)); 6048a138aedSMartin KaFai Lau if (!btf) 6058a138aedSMartin KaFai Lau return ERR_PTR(-ENOMEM); 6068a138aedSMartin KaFai Lau 6078a138aedSMartin KaFai Lau btf->fd = -1; 6088a138aedSMartin KaFai Lau 609b8604247SAndrii Nakryiko btf->raw_data = malloc(size); 610b8604247SAndrii Nakryiko if (!btf->raw_data) { 6118a138aedSMartin KaFai Lau err = -ENOMEM; 6128a138aedSMartin KaFai Lau goto done; 6138a138aedSMartin KaFai Lau } 614b8604247SAndrii Nakryiko memcpy(btf->raw_data, data, size); 615b8604247SAndrii Nakryiko btf->raw_size = size; 6168a138aedSMartin KaFai Lau 617b8604247SAndrii Nakryiko btf->hdr = btf->raw_data; 6188461ef8bSYonghong Song err = btf_parse_hdr(btf); 6198a138aedSMartin KaFai Lau if (err) 6208a138aedSMartin KaFai Lau goto done; 6218a138aedSMartin KaFai Lau 622b8604247SAndrii Nakryiko btf->strs_data = btf->raw_data + btf->hdr->hdr_len + btf->hdr->str_off; 623b8604247SAndrii Nakryiko btf->types_data = btf->raw_data + btf->hdr->hdr_len + btf->hdr->type_off; 6248a138aedSMartin KaFai Lau 625b8604247SAndrii Nakryiko err = btf_parse_str_sec(btf); 626b8604247SAndrii Nakryiko err = err ?: btf_parse_type_sec(btf); 6278a138aedSMartin KaFai Lau 6288a138aedSMartin KaFai Lau done: 6298a138aedSMartin KaFai Lau if (err) { 6308a138aedSMartin KaFai Lau btf__free(btf); 6318a138aedSMartin KaFai Lau return ERR_PTR(err); 6328a138aedSMartin KaFai Lau } 6338a138aedSMartin KaFai Lau 6348a138aedSMartin KaFai Lau return btf; 6358a138aedSMartin KaFai Lau } 6368a138aedSMartin KaFai Lau 637e6c64855SAndrii Nakryiko static bool btf_check_endianness(const GElf_Ehdr *ehdr) 638e6c64855SAndrii Nakryiko { 639cdb2f920SArnaldo Carvalho de Melo #if __BYTE_ORDER == __LITTLE_ENDIAN 640e6c64855SAndrii Nakryiko return ehdr->e_ident[EI_DATA] == ELFDATA2LSB; 641cdb2f920SArnaldo Carvalho de Melo #elif __BYTE_ORDER == __BIG_ENDIAN 642e6c64855SAndrii Nakryiko return ehdr->e_ident[EI_DATA] == ELFDATA2MSB; 643e6c64855SAndrii Nakryiko #else 644e6c64855SAndrii Nakryiko # error "Unrecognized __BYTE_ORDER__" 645e6c64855SAndrii Nakryiko #endif 646e6c64855SAndrii Nakryiko } 647e6c64855SAndrii Nakryiko 648e6c64855SAndrii Nakryiko struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext) 649e6c64855SAndrii Nakryiko { 650e6c64855SAndrii Nakryiko Elf_Data *btf_data = NULL, *btf_ext_data = NULL; 651e6c64855SAndrii Nakryiko int err = 0, fd = -1, idx = 0; 652e6c64855SAndrii Nakryiko struct btf *btf = NULL; 653e6c64855SAndrii Nakryiko Elf_Scn *scn = NULL; 654e6c64855SAndrii Nakryiko Elf *elf = NULL; 655e6c64855SAndrii Nakryiko GElf_Ehdr ehdr; 656e6c64855SAndrii Nakryiko 657e6c64855SAndrii Nakryiko if (elf_version(EV_CURRENT) == EV_NONE) { 658be18010eSKefeng Wang pr_warn("failed to init libelf for %s\n", path); 659e6c64855SAndrii Nakryiko return ERR_PTR(-LIBBPF_ERRNO__LIBELF); 660e6c64855SAndrii Nakryiko } 661e6c64855SAndrii Nakryiko 662e6c64855SAndrii Nakryiko fd = open(path, O_RDONLY); 663e6c64855SAndrii Nakryiko if (fd < 0) { 664e6c64855SAndrii Nakryiko err = -errno; 665be18010eSKefeng Wang pr_warn("failed to open %s: %s\n", path, strerror(errno)); 666e6c64855SAndrii Nakryiko return ERR_PTR(err); 667e6c64855SAndrii Nakryiko } 668e6c64855SAndrii Nakryiko 669e6c64855SAndrii Nakryiko err = -LIBBPF_ERRNO__FORMAT; 670e6c64855SAndrii Nakryiko 671e6c64855SAndrii Nakryiko elf = elf_begin(fd, ELF_C_READ, NULL); 672e6c64855SAndrii Nakryiko if (!elf) { 673be18010eSKefeng Wang pr_warn("failed to open %s as ELF file\n", path); 674e6c64855SAndrii Nakryiko goto done; 675e6c64855SAndrii Nakryiko } 676e6c64855SAndrii Nakryiko if (!gelf_getehdr(elf, &ehdr)) { 677be18010eSKefeng Wang pr_warn("failed to get EHDR from %s\n", path); 678e6c64855SAndrii Nakryiko goto done; 679e6c64855SAndrii Nakryiko } 680e6c64855SAndrii Nakryiko if (!btf_check_endianness(&ehdr)) { 681be18010eSKefeng Wang pr_warn("non-native ELF endianness is not supported\n"); 682e6c64855SAndrii Nakryiko goto done; 683e6c64855SAndrii Nakryiko } 684e6c64855SAndrii Nakryiko if (!elf_rawdata(elf_getscn(elf, ehdr.e_shstrndx), NULL)) { 685be18010eSKefeng Wang pr_warn("failed to get e_shstrndx from %s\n", path); 686e6c64855SAndrii Nakryiko goto done; 687e6c64855SAndrii Nakryiko } 688e6c64855SAndrii Nakryiko 689e6c64855SAndrii Nakryiko while ((scn = elf_nextscn(elf, scn)) != NULL) { 690e6c64855SAndrii Nakryiko GElf_Shdr sh; 691e6c64855SAndrii Nakryiko char *name; 692e6c64855SAndrii Nakryiko 693e6c64855SAndrii Nakryiko idx++; 694e6c64855SAndrii Nakryiko if (gelf_getshdr(scn, &sh) != &sh) { 695be18010eSKefeng Wang pr_warn("failed to get section(%d) header from %s\n", 696e6c64855SAndrii Nakryiko idx, path); 697e6c64855SAndrii Nakryiko goto done; 698e6c64855SAndrii Nakryiko } 699e6c64855SAndrii Nakryiko name = elf_strptr(elf, ehdr.e_shstrndx, sh.sh_name); 700e6c64855SAndrii Nakryiko if (!name) { 701be18010eSKefeng Wang pr_warn("failed to get section(%d) name from %s\n", 702e6c64855SAndrii Nakryiko idx, path); 703e6c64855SAndrii Nakryiko goto done; 704e6c64855SAndrii Nakryiko } 705e6c64855SAndrii Nakryiko if (strcmp(name, BTF_ELF_SEC) == 0) { 706e6c64855SAndrii Nakryiko btf_data = elf_getdata(scn, 0); 707e6c64855SAndrii Nakryiko if (!btf_data) { 708be18010eSKefeng Wang pr_warn("failed to get section(%d, %s) data from %s\n", 709e6c64855SAndrii Nakryiko idx, name, path); 710e6c64855SAndrii Nakryiko goto done; 711e6c64855SAndrii Nakryiko } 712e6c64855SAndrii Nakryiko continue; 713e6c64855SAndrii Nakryiko } else if (btf_ext && strcmp(name, BTF_EXT_ELF_SEC) == 0) { 714e6c64855SAndrii Nakryiko btf_ext_data = elf_getdata(scn, 0); 715e6c64855SAndrii Nakryiko if (!btf_ext_data) { 716be18010eSKefeng Wang pr_warn("failed to get section(%d, %s) data from %s\n", 717e6c64855SAndrii Nakryiko idx, name, path); 718e6c64855SAndrii Nakryiko goto done; 719e6c64855SAndrii Nakryiko } 720e6c64855SAndrii Nakryiko continue; 721e6c64855SAndrii Nakryiko } 722e6c64855SAndrii Nakryiko } 723e6c64855SAndrii Nakryiko 724e6c64855SAndrii Nakryiko err = 0; 725e6c64855SAndrii Nakryiko 726e6c64855SAndrii Nakryiko if (!btf_data) { 727e6c64855SAndrii Nakryiko err = -ENOENT; 728e6c64855SAndrii Nakryiko goto done; 729e6c64855SAndrii Nakryiko } 730e6c64855SAndrii Nakryiko btf = btf__new(btf_data->d_buf, btf_data->d_size); 731e6c64855SAndrii Nakryiko if (IS_ERR(btf)) 732e6c64855SAndrii Nakryiko goto done; 733e6c64855SAndrii Nakryiko 73444ad23dfSAndrii Nakryiko switch (gelf_getclass(elf)) { 73544ad23dfSAndrii Nakryiko case ELFCLASS32: 73644ad23dfSAndrii Nakryiko btf__set_pointer_size(btf, 4); 73744ad23dfSAndrii Nakryiko break; 73844ad23dfSAndrii Nakryiko case ELFCLASS64: 73944ad23dfSAndrii Nakryiko btf__set_pointer_size(btf, 8); 74044ad23dfSAndrii Nakryiko break; 74144ad23dfSAndrii Nakryiko default: 74244ad23dfSAndrii Nakryiko pr_warn("failed to get ELF class (bitness) for %s\n", path); 74344ad23dfSAndrii Nakryiko break; 74444ad23dfSAndrii Nakryiko } 74544ad23dfSAndrii Nakryiko 746e6c64855SAndrii Nakryiko if (btf_ext && btf_ext_data) { 747e6c64855SAndrii Nakryiko *btf_ext = btf_ext__new(btf_ext_data->d_buf, 748e6c64855SAndrii Nakryiko btf_ext_data->d_size); 749e6c64855SAndrii Nakryiko if (IS_ERR(*btf_ext)) 750e6c64855SAndrii Nakryiko goto done; 751e6c64855SAndrii Nakryiko } else if (btf_ext) { 752e6c64855SAndrii Nakryiko *btf_ext = NULL; 753e6c64855SAndrii Nakryiko } 754e6c64855SAndrii Nakryiko done: 755e6c64855SAndrii Nakryiko if (elf) 756e6c64855SAndrii Nakryiko elf_end(elf); 757e6c64855SAndrii Nakryiko close(fd); 758e6c64855SAndrii Nakryiko 759e6c64855SAndrii Nakryiko if (err) 760e6c64855SAndrii Nakryiko return ERR_PTR(err); 761e6c64855SAndrii Nakryiko /* 762e6c64855SAndrii Nakryiko * btf is always parsed before btf_ext, so no need to clean up 763e6c64855SAndrii Nakryiko * btf_ext, if btf loading failed 764e6c64855SAndrii Nakryiko */ 765e6c64855SAndrii Nakryiko if (IS_ERR(btf)) 766e6c64855SAndrii Nakryiko return btf; 767e6c64855SAndrii Nakryiko if (btf_ext && IS_ERR(*btf_ext)) { 768e6c64855SAndrii Nakryiko btf__free(btf); 769e6c64855SAndrii Nakryiko err = PTR_ERR(*btf_ext); 770e6c64855SAndrii Nakryiko return ERR_PTR(err); 771e6c64855SAndrii Nakryiko } 772e6c64855SAndrii Nakryiko return btf; 773e6c64855SAndrii Nakryiko } 774e6c64855SAndrii Nakryiko 77594a1feddSAndrii Nakryiko struct btf *btf__parse_raw(const char *path) 77694a1feddSAndrii Nakryiko { 777932ac54aSDaniel T. Lee struct btf *btf = NULL; 77894a1feddSAndrii Nakryiko void *data = NULL; 77994a1feddSAndrii Nakryiko FILE *f = NULL; 78094a1feddSAndrii Nakryiko __u16 magic; 78194a1feddSAndrii Nakryiko int err = 0; 78294a1feddSAndrii Nakryiko long sz; 78394a1feddSAndrii Nakryiko 78494a1feddSAndrii Nakryiko f = fopen(path, "rb"); 78594a1feddSAndrii Nakryiko if (!f) { 78694a1feddSAndrii Nakryiko err = -errno; 78794a1feddSAndrii Nakryiko goto err_out; 78894a1feddSAndrii Nakryiko } 78994a1feddSAndrii Nakryiko 79094a1feddSAndrii Nakryiko /* check BTF magic */ 79194a1feddSAndrii Nakryiko if (fread(&magic, 1, sizeof(magic), f) < sizeof(magic)) { 79294a1feddSAndrii Nakryiko err = -EIO; 79394a1feddSAndrii Nakryiko goto err_out; 79494a1feddSAndrii Nakryiko } 79594a1feddSAndrii Nakryiko if (magic != BTF_MAGIC) { 79694a1feddSAndrii Nakryiko /* definitely not a raw BTF */ 79794a1feddSAndrii Nakryiko err = -EPROTO; 79894a1feddSAndrii Nakryiko goto err_out; 79994a1feddSAndrii Nakryiko } 80094a1feddSAndrii Nakryiko 80194a1feddSAndrii Nakryiko /* get file size */ 80294a1feddSAndrii Nakryiko if (fseek(f, 0, SEEK_END)) { 80394a1feddSAndrii Nakryiko err = -errno; 80494a1feddSAndrii Nakryiko goto err_out; 80594a1feddSAndrii Nakryiko } 80694a1feddSAndrii Nakryiko sz = ftell(f); 80794a1feddSAndrii Nakryiko if (sz < 0) { 80894a1feddSAndrii Nakryiko err = -errno; 80994a1feddSAndrii Nakryiko goto err_out; 81094a1feddSAndrii Nakryiko } 81194a1feddSAndrii Nakryiko /* rewind to the start */ 81294a1feddSAndrii Nakryiko if (fseek(f, 0, SEEK_SET)) { 81394a1feddSAndrii Nakryiko err = -errno; 81494a1feddSAndrii Nakryiko goto err_out; 81594a1feddSAndrii Nakryiko } 81694a1feddSAndrii Nakryiko 81794a1feddSAndrii Nakryiko /* pre-alloc memory and read all of BTF data */ 81894a1feddSAndrii Nakryiko data = malloc(sz); 81994a1feddSAndrii Nakryiko if (!data) { 82094a1feddSAndrii Nakryiko err = -ENOMEM; 82194a1feddSAndrii Nakryiko goto err_out; 82294a1feddSAndrii Nakryiko } 82394a1feddSAndrii Nakryiko if (fread(data, 1, sz, f) < sz) { 82494a1feddSAndrii Nakryiko err = -EIO; 82594a1feddSAndrii Nakryiko goto err_out; 82694a1feddSAndrii Nakryiko } 82794a1feddSAndrii Nakryiko 82894a1feddSAndrii Nakryiko /* finally parse BTF data */ 82994a1feddSAndrii Nakryiko btf = btf__new(data, sz); 83094a1feddSAndrii Nakryiko 83194a1feddSAndrii Nakryiko err_out: 83294a1feddSAndrii Nakryiko free(data); 83394a1feddSAndrii Nakryiko if (f) 83494a1feddSAndrii Nakryiko fclose(f); 83594a1feddSAndrii Nakryiko return err ? ERR_PTR(err) : btf; 83694a1feddSAndrii Nakryiko } 83794a1feddSAndrii Nakryiko 83894a1feddSAndrii Nakryiko struct btf *btf__parse(const char *path, struct btf_ext **btf_ext) 83994a1feddSAndrii Nakryiko { 84094a1feddSAndrii Nakryiko struct btf *btf; 84194a1feddSAndrii Nakryiko 84294a1feddSAndrii Nakryiko if (btf_ext) 84394a1feddSAndrii Nakryiko *btf_ext = NULL; 84494a1feddSAndrii Nakryiko 84594a1feddSAndrii Nakryiko btf = btf__parse_raw(path); 84694a1feddSAndrii Nakryiko if (!IS_ERR(btf) || PTR_ERR(btf) != -EPROTO) 84794a1feddSAndrii Nakryiko return btf; 84894a1feddSAndrii Nakryiko 84994a1feddSAndrii Nakryiko return btf__parse_elf(path, btf_ext); 85094a1feddSAndrii Nakryiko } 85194a1feddSAndrii Nakryiko 8521713d68bSDaniel Borkmann static int compare_vsi_off(const void *_a, const void *_b) 8531713d68bSDaniel Borkmann { 8541713d68bSDaniel Borkmann const struct btf_var_secinfo *a = _a; 8551713d68bSDaniel Borkmann const struct btf_var_secinfo *b = _b; 8561713d68bSDaniel Borkmann 8571713d68bSDaniel Borkmann return a->offset - b->offset; 8581713d68bSDaniel Borkmann } 8591713d68bSDaniel Borkmann 8601713d68bSDaniel Borkmann static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf, 8611713d68bSDaniel Borkmann struct btf_type *t) 8621713d68bSDaniel Borkmann { 863b03bc685SAndrii Nakryiko __u32 size = 0, off = 0, i, vars = btf_vlen(t); 8641713d68bSDaniel Borkmann const char *name = btf__name_by_offset(btf, t->name_off); 8651713d68bSDaniel Borkmann const struct btf_type *t_var; 8661713d68bSDaniel Borkmann struct btf_var_secinfo *vsi; 867b03bc685SAndrii Nakryiko const struct btf_var *var; 8681713d68bSDaniel Borkmann int ret; 8691713d68bSDaniel Borkmann 8701713d68bSDaniel Borkmann if (!name) { 8711713d68bSDaniel Borkmann pr_debug("No name found in string section for DATASEC kind.\n"); 8721713d68bSDaniel Borkmann return -ENOENT; 8731713d68bSDaniel Borkmann } 8741713d68bSDaniel Borkmann 875166750bcSAndrii Nakryiko /* .extern datasec size and var offsets were set correctly during 876166750bcSAndrii Nakryiko * extern collection step, so just skip straight to sorting variables 877166750bcSAndrii Nakryiko */ 878166750bcSAndrii Nakryiko if (t->size) 879166750bcSAndrii Nakryiko goto sort_vars; 880166750bcSAndrii Nakryiko 8811713d68bSDaniel Borkmann ret = bpf_object__section_size(obj, name, &size); 8821713d68bSDaniel Borkmann if (ret || !size || (t->size && t->size != size)) { 8831713d68bSDaniel Borkmann pr_debug("Invalid size for section %s: %u bytes\n", name, size); 8841713d68bSDaniel Borkmann return -ENOENT; 8851713d68bSDaniel Borkmann } 8861713d68bSDaniel Borkmann 8871713d68bSDaniel Borkmann t->size = size; 8881713d68bSDaniel Borkmann 889b03bc685SAndrii Nakryiko for (i = 0, vsi = btf_var_secinfos(t); i < vars; i++, vsi++) { 8901713d68bSDaniel Borkmann t_var = btf__type_by_id(btf, vsi->type); 891b03bc685SAndrii Nakryiko var = btf_var(t_var); 8921713d68bSDaniel Borkmann 893b03bc685SAndrii Nakryiko if (!btf_is_var(t_var)) { 8941713d68bSDaniel Borkmann pr_debug("Non-VAR type seen in section %s\n", name); 8951713d68bSDaniel Borkmann return -EINVAL; 8961713d68bSDaniel Borkmann } 8971713d68bSDaniel Borkmann 8981713d68bSDaniel Borkmann if (var->linkage == BTF_VAR_STATIC) 8991713d68bSDaniel Borkmann continue; 9001713d68bSDaniel Borkmann 9011713d68bSDaniel Borkmann name = btf__name_by_offset(btf, t_var->name_off); 9021713d68bSDaniel Borkmann if (!name) { 9031713d68bSDaniel Borkmann pr_debug("No name found in string section for VAR kind\n"); 9041713d68bSDaniel Borkmann return -ENOENT; 9051713d68bSDaniel Borkmann } 9061713d68bSDaniel Borkmann 9071713d68bSDaniel Borkmann ret = bpf_object__variable_offset(obj, name, &off); 9081713d68bSDaniel Borkmann if (ret) { 909b03bc685SAndrii Nakryiko pr_debug("No offset found in symbol table for VAR %s\n", 910b03bc685SAndrii Nakryiko name); 9111713d68bSDaniel Borkmann return -ENOENT; 9121713d68bSDaniel Borkmann } 9131713d68bSDaniel Borkmann 9141713d68bSDaniel Borkmann vsi->offset = off; 9151713d68bSDaniel Borkmann } 9161713d68bSDaniel Borkmann 917166750bcSAndrii Nakryiko sort_vars: 918166750bcSAndrii Nakryiko qsort(btf_var_secinfos(t), vars, sizeof(*vsi), compare_vsi_off); 9191713d68bSDaniel Borkmann return 0; 9201713d68bSDaniel Borkmann } 9211713d68bSDaniel Borkmann 9221713d68bSDaniel Borkmann int btf__finalize_data(struct bpf_object *obj, struct btf *btf) 9231713d68bSDaniel Borkmann { 9241713d68bSDaniel Borkmann int err = 0; 9251713d68bSDaniel Borkmann __u32 i; 9261713d68bSDaniel Borkmann 9271713d68bSDaniel Borkmann for (i = 1; i <= btf->nr_types; i++) { 928740e69c3SAndrii Nakryiko struct btf_type *t = btf_type_by_id(btf, i); 9291713d68bSDaniel Borkmann 9301713d68bSDaniel Borkmann /* Loader needs to fix up some of the things compiler 9311713d68bSDaniel Borkmann * couldn't get its hands on while emitting BTF. This 9321713d68bSDaniel Borkmann * is section size and global variable offset. We use 9331713d68bSDaniel Borkmann * the info from the ELF itself for this purpose. 9341713d68bSDaniel Borkmann */ 935b03bc685SAndrii Nakryiko if (btf_is_datasec(t)) { 9361713d68bSDaniel Borkmann err = btf_fixup_datasec(obj, btf, t); 9371713d68bSDaniel Borkmann if (err) 9381713d68bSDaniel Borkmann break; 9391713d68bSDaniel Borkmann } 9401713d68bSDaniel Borkmann } 9411713d68bSDaniel Borkmann 9421713d68bSDaniel Borkmann return err; 9431713d68bSDaniel Borkmann } 9441713d68bSDaniel Borkmann 945d29d87f7SAndrii Nakryiko int btf__load(struct btf *btf) 946d29d87f7SAndrii Nakryiko { 947b8604247SAndrii Nakryiko __u32 log_buf_size = 0, raw_size; 948d29d87f7SAndrii Nakryiko char *log_buf = NULL; 949b8604247SAndrii Nakryiko const void *raw_data; 950d29d87f7SAndrii Nakryiko int err = 0; 951d29d87f7SAndrii Nakryiko 952d29d87f7SAndrii Nakryiko if (btf->fd >= 0) 953d29d87f7SAndrii Nakryiko return -EEXIST; 954d29d87f7SAndrii Nakryiko 9558395f320SStanislav Fomichev retry_load: 9568395f320SStanislav Fomichev if (log_buf_size) { 957d29d87f7SAndrii Nakryiko log_buf = malloc(log_buf_size); 958d29d87f7SAndrii Nakryiko if (!log_buf) 959d29d87f7SAndrii Nakryiko return -ENOMEM; 960d29d87f7SAndrii Nakryiko 961d29d87f7SAndrii Nakryiko *log_buf = 0; 9628395f320SStanislav Fomichev } 963d29d87f7SAndrii Nakryiko 964b8604247SAndrii Nakryiko raw_data = btf__get_raw_data(btf, &raw_size); 965b8604247SAndrii Nakryiko if (!raw_data) { 966b8604247SAndrii Nakryiko err = -ENOMEM; 967b8604247SAndrii Nakryiko goto done; 968b8604247SAndrii Nakryiko } 969b8604247SAndrii Nakryiko 970b8604247SAndrii Nakryiko btf->fd = bpf_load_btf(raw_data, raw_size, log_buf, log_buf_size, false); 971d29d87f7SAndrii Nakryiko if (btf->fd < 0) { 9728395f320SStanislav Fomichev if (!log_buf || errno == ENOSPC) { 9738395f320SStanislav Fomichev log_buf_size = max((__u32)BPF_LOG_BUF_SIZE, 9748395f320SStanislav Fomichev log_buf_size << 1); 9758395f320SStanislav Fomichev free(log_buf); 9768395f320SStanislav Fomichev goto retry_load; 9778395f320SStanislav Fomichev } 9788395f320SStanislav Fomichev 979d29d87f7SAndrii Nakryiko err = -errno; 980be18010eSKefeng Wang pr_warn("Error loading BTF: %s(%d)\n", strerror(errno), errno); 981d29d87f7SAndrii Nakryiko if (*log_buf) 982be18010eSKefeng Wang pr_warn("%s\n", log_buf); 983d29d87f7SAndrii Nakryiko goto done; 984d29d87f7SAndrii Nakryiko } 985d29d87f7SAndrii Nakryiko 986d29d87f7SAndrii Nakryiko done: 987d29d87f7SAndrii Nakryiko free(log_buf); 988d29d87f7SAndrii Nakryiko return err; 989d29d87f7SAndrii Nakryiko } 990d29d87f7SAndrii Nakryiko 9918a138aedSMartin KaFai Lau int btf__fd(const struct btf *btf) 9928a138aedSMartin KaFai Lau { 9938a138aedSMartin KaFai Lau return btf->fd; 9948a138aedSMartin KaFai Lau } 99592b57121SOkash Khawaja 99681372e12SAndrii Nakryiko void btf__set_fd(struct btf *btf, int fd) 99781372e12SAndrii Nakryiko { 99881372e12SAndrii Nakryiko btf->fd = fd; 99981372e12SAndrii Nakryiko } 100081372e12SAndrii Nakryiko 1001919d2b1dSAndrii Nakryiko const void *btf__get_raw_data(const struct btf *btf_ro, __u32 *size) 100202c87446SAndrii Nakryiko { 1003919d2b1dSAndrii Nakryiko struct btf *btf = (struct btf *)btf_ro; 1004919d2b1dSAndrii Nakryiko 1005919d2b1dSAndrii Nakryiko if (!btf->raw_data) { 1006919d2b1dSAndrii Nakryiko struct btf_header *hdr = btf->hdr; 1007919d2b1dSAndrii Nakryiko void *data; 1008919d2b1dSAndrii Nakryiko 1009919d2b1dSAndrii Nakryiko btf->raw_size = hdr->hdr_len + hdr->type_len + hdr->str_len; 1010919d2b1dSAndrii Nakryiko btf->raw_data = calloc(1, btf->raw_size); 1011919d2b1dSAndrii Nakryiko if (!btf->raw_data) 1012919d2b1dSAndrii Nakryiko return NULL; 1013919d2b1dSAndrii Nakryiko data = btf->raw_data; 1014919d2b1dSAndrii Nakryiko 1015919d2b1dSAndrii Nakryiko memcpy(data, hdr, hdr->hdr_len); 1016919d2b1dSAndrii Nakryiko data += hdr->hdr_len; 1017919d2b1dSAndrii Nakryiko 1018919d2b1dSAndrii Nakryiko memcpy(data, btf->types_data, hdr->type_len); 1019919d2b1dSAndrii Nakryiko data += hdr->type_len; 1020919d2b1dSAndrii Nakryiko 1021919d2b1dSAndrii Nakryiko memcpy(data, btf->strs_data, hdr->str_len); 1022919d2b1dSAndrii Nakryiko data += hdr->str_len; 1023919d2b1dSAndrii Nakryiko } 1024b8604247SAndrii Nakryiko *size = btf->raw_size; 1025b8604247SAndrii Nakryiko return btf->raw_data; 102602c87446SAndrii Nakryiko } 102702c87446SAndrii Nakryiko 102892b57121SOkash Khawaja const char *btf__name_by_offset(const struct btf *btf, __u32 offset) 102992b57121SOkash Khawaja { 103092b57121SOkash Khawaja if (offset < btf->hdr->str_len) 1031b8604247SAndrii Nakryiko return btf->strs_data + offset; 103292b57121SOkash Khawaja else 103392b57121SOkash Khawaja return NULL; 103492b57121SOkash Khawaja } 10352993e051SYonghong Song 10361d2f44caSMartin KaFai Lau int btf__get_from_id(__u32 id, struct btf **btf) 1037d7f5b5e0SYonghong Song { 1038d7f5b5e0SYonghong Song struct bpf_btf_info btf_info = { 0 }; 1039d7f5b5e0SYonghong Song __u32 len = sizeof(btf_info); 1040d7f5b5e0SYonghong Song __u32 last_size; 1041d7f5b5e0SYonghong Song int btf_fd; 1042d7f5b5e0SYonghong Song void *ptr; 1043d7f5b5e0SYonghong Song int err; 1044d7f5b5e0SYonghong Song 1045d7f5b5e0SYonghong Song err = 0; 1046d7f5b5e0SYonghong Song *btf = NULL; 1047d7f5b5e0SYonghong Song btf_fd = bpf_btf_get_fd_by_id(id); 1048d7f5b5e0SYonghong Song if (btf_fd < 0) 1049d7f5b5e0SYonghong Song return 0; 1050d7f5b5e0SYonghong Song 1051d7f5b5e0SYonghong Song /* we won't know btf_size until we call bpf_obj_get_info_by_fd(). so 1052d7f5b5e0SYonghong Song * let's start with a sane default - 4KiB here - and resize it only if 1053d7f5b5e0SYonghong Song * bpf_obj_get_info_by_fd() needs a bigger buffer. 1054d7f5b5e0SYonghong Song */ 1055d7f5b5e0SYonghong Song btf_info.btf_size = 4096; 1056d7f5b5e0SYonghong Song last_size = btf_info.btf_size; 1057d7f5b5e0SYonghong Song ptr = malloc(last_size); 1058d7f5b5e0SYonghong Song if (!ptr) { 1059d7f5b5e0SYonghong Song err = -ENOMEM; 1060d7f5b5e0SYonghong Song goto exit_free; 1061d7f5b5e0SYonghong Song } 1062d7f5b5e0SYonghong Song 10631ad9cbb8SAndrii Nakryiko memset(ptr, 0, last_size); 1064d7f5b5e0SYonghong Song btf_info.btf = ptr_to_u64(ptr); 1065d7f5b5e0SYonghong Song err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); 1066d7f5b5e0SYonghong Song 1067d7f5b5e0SYonghong Song if (!err && btf_info.btf_size > last_size) { 1068d7f5b5e0SYonghong Song void *temp_ptr; 1069d7f5b5e0SYonghong Song 1070d7f5b5e0SYonghong Song last_size = btf_info.btf_size; 1071d7f5b5e0SYonghong Song temp_ptr = realloc(ptr, last_size); 1072d7f5b5e0SYonghong Song if (!temp_ptr) { 1073d7f5b5e0SYonghong Song err = -ENOMEM; 1074d7f5b5e0SYonghong Song goto exit_free; 1075d7f5b5e0SYonghong Song } 1076d7f5b5e0SYonghong Song ptr = temp_ptr; 10771ad9cbb8SAndrii Nakryiko memset(ptr, 0, last_size); 1078d7f5b5e0SYonghong Song btf_info.btf = ptr_to_u64(ptr); 1079d7f5b5e0SYonghong Song err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); 1080d7f5b5e0SYonghong Song } 1081d7f5b5e0SYonghong Song 1082d7f5b5e0SYonghong Song if (err || btf_info.btf_size > last_size) { 1083d7f5b5e0SYonghong Song err = errno; 1084d7f5b5e0SYonghong Song goto exit_free; 1085d7f5b5e0SYonghong Song } 1086d7f5b5e0SYonghong Song 10878461ef8bSYonghong Song *btf = btf__new((__u8 *)(long)btf_info.btf, btf_info.btf_size); 1088d7f5b5e0SYonghong Song if (IS_ERR(*btf)) { 1089d7f5b5e0SYonghong Song err = PTR_ERR(*btf); 1090d7f5b5e0SYonghong Song *btf = NULL; 1091d7f5b5e0SYonghong Song } 1092d7f5b5e0SYonghong Song 1093d7f5b5e0SYonghong Song exit_free: 1094d7f5b5e0SYonghong Song close(btf_fd); 1095d7f5b5e0SYonghong Song free(ptr); 1096d7f5b5e0SYonghong Song 1097d7f5b5e0SYonghong Song return err; 1098d7f5b5e0SYonghong Song } 1099d7f5b5e0SYonghong Song 1100a6c109a6SYonghong Song int btf__get_map_kv_tids(const struct btf *btf, const char *map_name, 110196408c43SYonghong Song __u32 expected_key_size, __u32 expected_value_size, 110296408c43SYonghong Song __u32 *key_type_id, __u32 *value_type_id) 110396408c43SYonghong Song { 110496408c43SYonghong Song const struct btf_type *container_type; 110596408c43SYonghong Song const struct btf_member *key, *value; 110696408c43SYonghong Song const size_t max_name = 256; 110796408c43SYonghong Song char container_name[max_name]; 110896408c43SYonghong Song __s64 key_size, value_size; 110996408c43SYonghong Song __s32 container_id; 111096408c43SYonghong Song 111196408c43SYonghong Song if (snprintf(container_name, max_name, "____btf_map_%s", map_name) == 111296408c43SYonghong Song max_name) { 1113be18010eSKefeng Wang pr_warn("map:%s length of '____btf_map_%s' is too long\n", 111496408c43SYonghong Song map_name, map_name); 111596408c43SYonghong Song return -EINVAL; 111696408c43SYonghong Song } 111796408c43SYonghong Song 111896408c43SYonghong Song container_id = btf__find_by_name(btf, container_name); 111996408c43SYonghong Song if (container_id < 0) { 1120f7748e29SYonghong Song pr_debug("map:%s container_name:%s cannot be found in BTF. Missing BPF_ANNOTATE_KV_PAIR?\n", 112196408c43SYonghong Song map_name, container_name); 112296408c43SYonghong Song return container_id; 112396408c43SYonghong Song } 112496408c43SYonghong Song 112596408c43SYonghong Song container_type = btf__type_by_id(btf, container_id); 112696408c43SYonghong Song if (!container_type) { 1127be18010eSKefeng Wang pr_warn("map:%s cannot find BTF type for container_id:%u\n", 112896408c43SYonghong Song map_name, container_id); 112996408c43SYonghong Song return -EINVAL; 113096408c43SYonghong Song } 113196408c43SYonghong Song 1132b03bc685SAndrii Nakryiko if (!btf_is_struct(container_type) || btf_vlen(container_type) < 2) { 1133be18010eSKefeng Wang pr_warn("map:%s container_name:%s is an invalid container struct\n", 113496408c43SYonghong Song map_name, container_name); 113596408c43SYonghong Song return -EINVAL; 113696408c43SYonghong Song } 113796408c43SYonghong Song 1138b03bc685SAndrii Nakryiko key = btf_members(container_type); 113996408c43SYonghong Song value = key + 1; 114096408c43SYonghong Song 114196408c43SYonghong Song key_size = btf__resolve_size(btf, key->type); 114296408c43SYonghong Song if (key_size < 0) { 1143be18010eSKefeng Wang pr_warn("map:%s invalid BTF key_type_size\n", map_name); 114496408c43SYonghong Song return key_size; 114596408c43SYonghong Song } 114696408c43SYonghong Song 114796408c43SYonghong Song if (expected_key_size != key_size) { 1148be18010eSKefeng Wang pr_warn("map:%s btf_key_type_size:%u != map_def_key_size:%u\n", 114996408c43SYonghong Song map_name, (__u32)key_size, expected_key_size); 115096408c43SYonghong Song return -EINVAL; 115196408c43SYonghong Song } 115296408c43SYonghong Song 115396408c43SYonghong Song value_size = btf__resolve_size(btf, value->type); 115496408c43SYonghong Song if (value_size < 0) { 1155be18010eSKefeng Wang pr_warn("map:%s invalid BTF value_type_size\n", map_name); 115696408c43SYonghong Song return value_size; 115796408c43SYonghong Song } 115896408c43SYonghong Song 115996408c43SYonghong Song if (expected_value_size != value_size) { 1160be18010eSKefeng Wang pr_warn("map:%s btf_value_type_size:%u != map_def_value_size:%u\n", 116196408c43SYonghong Song map_name, (__u32)value_size, expected_value_size); 116296408c43SYonghong Song return -EINVAL; 116396408c43SYonghong Song } 116496408c43SYonghong Song 116596408c43SYonghong Song *key_type_id = key->type; 116696408c43SYonghong Song *value_type_id = value->type; 116796408c43SYonghong Song 116896408c43SYonghong Song return 0; 116996408c43SYonghong Song } 117096408c43SYonghong Song 1171919d2b1dSAndrii Nakryiko static size_t strs_hash_fn(const void *key, void *ctx) 1172919d2b1dSAndrii Nakryiko { 1173919d2b1dSAndrii Nakryiko struct btf *btf = ctx; 1174919d2b1dSAndrii Nakryiko const char *str = btf->strs_data + (long)key; 1175919d2b1dSAndrii Nakryiko 1176919d2b1dSAndrii Nakryiko return str_hash(str); 1177919d2b1dSAndrii Nakryiko } 1178919d2b1dSAndrii Nakryiko 1179919d2b1dSAndrii Nakryiko static bool strs_hash_equal_fn(const void *key1, const void *key2, void *ctx) 1180919d2b1dSAndrii Nakryiko { 1181919d2b1dSAndrii Nakryiko struct btf *btf = ctx; 1182919d2b1dSAndrii Nakryiko const char *str1 = btf->strs_data + (long)key1; 1183919d2b1dSAndrii Nakryiko const char *str2 = btf->strs_data + (long)key2; 1184919d2b1dSAndrii Nakryiko 1185919d2b1dSAndrii Nakryiko return strcmp(str1, str2) == 0; 1186919d2b1dSAndrii Nakryiko } 1187919d2b1dSAndrii Nakryiko 1188919d2b1dSAndrii Nakryiko /* Ensure BTF is ready to be modified (by splitting into a three memory 1189919d2b1dSAndrii Nakryiko * regions for header, types, and strings). Also invalidate cached 1190919d2b1dSAndrii Nakryiko * raw_data, if any. 1191919d2b1dSAndrii Nakryiko */ 1192919d2b1dSAndrii Nakryiko static int btf_ensure_modifiable(struct btf *btf) 1193919d2b1dSAndrii Nakryiko { 1194919d2b1dSAndrii Nakryiko void *hdr, *types, *strs, *strs_end, *s; 1195919d2b1dSAndrii Nakryiko struct hashmap *hash = NULL; 1196919d2b1dSAndrii Nakryiko long off; 1197919d2b1dSAndrii Nakryiko int err; 1198919d2b1dSAndrii Nakryiko 1199919d2b1dSAndrii Nakryiko if (btf_is_modifiable(btf)) { 1200919d2b1dSAndrii Nakryiko /* any BTF modification invalidates raw_data */ 1201919d2b1dSAndrii Nakryiko if (btf->raw_data) { 1202919d2b1dSAndrii Nakryiko free(btf->raw_data); 1203919d2b1dSAndrii Nakryiko btf->raw_data = NULL; 1204919d2b1dSAndrii Nakryiko } 1205919d2b1dSAndrii Nakryiko return 0; 1206919d2b1dSAndrii Nakryiko } 1207919d2b1dSAndrii Nakryiko 1208919d2b1dSAndrii Nakryiko /* split raw data into three memory regions */ 1209919d2b1dSAndrii Nakryiko hdr = malloc(btf->hdr->hdr_len); 1210919d2b1dSAndrii Nakryiko types = malloc(btf->hdr->type_len); 1211919d2b1dSAndrii Nakryiko strs = malloc(btf->hdr->str_len); 1212919d2b1dSAndrii Nakryiko if (!hdr || !types || !strs) 1213919d2b1dSAndrii Nakryiko goto err_out; 1214919d2b1dSAndrii Nakryiko 1215919d2b1dSAndrii Nakryiko memcpy(hdr, btf->hdr, btf->hdr->hdr_len); 1216919d2b1dSAndrii Nakryiko memcpy(types, btf->types_data, btf->hdr->type_len); 1217919d2b1dSAndrii Nakryiko memcpy(strs, btf->strs_data, btf->hdr->str_len); 1218919d2b1dSAndrii Nakryiko 1219919d2b1dSAndrii Nakryiko /* build lookup index for all strings */ 1220919d2b1dSAndrii Nakryiko hash = hashmap__new(strs_hash_fn, strs_hash_equal_fn, btf); 1221919d2b1dSAndrii Nakryiko if (IS_ERR(hash)) { 1222919d2b1dSAndrii Nakryiko err = PTR_ERR(hash); 1223919d2b1dSAndrii Nakryiko hash = NULL; 1224919d2b1dSAndrii Nakryiko goto err_out; 1225919d2b1dSAndrii Nakryiko } 1226919d2b1dSAndrii Nakryiko 1227919d2b1dSAndrii Nakryiko strs_end = strs + btf->hdr->str_len; 1228919d2b1dSAndrii Nakryiko for (off = 0, s = strs; s < strs_end; off += strlen(s) + 1, s = strs + off) { 1229919d2b1dSAndrii Nakryiko /* hashmap__add() returns EEXIST if string with the same 1230919d2b1dSAndrii Nakryiko * content already is in the hash map 1231919d2b1dSAndrii Nakryiko */ 1232919d2b1dSAndrii Nakryiko err = hashmap__add(hash, (void *)off, (void *)off); 1233919d2b1dSAndrii Nakryiko if (err == -EEXIST) 1234919d2b1dSAndrii Nakryiko continue; /* duplicate */ 1235919d2b1dSAndrii Nakryiko if (err) 1236919d2b1dSAndrii Nakryiko goto err_out; 1237919d2b1dSAndrii Nakryiko } 1238919d2b1dSAndrii Nakryiko 1239919d2b1dSAndrii Nakryiko /* only when everything was successful, update internal state */ 1240919d2b1dSAndrii Nakryiko btf->hdr = hdr; 1241919d2b1dSAndrii Nakryiko btf->types_data = types; 1242919d2b1dSAndrii Nakryiko btf->types_data_cap = btf->hdr->type_len; 1243919d2b1dSAndrii Nakryiko btf->strs_data = strs; 1244919d2b1dSAndrii Nakryiko btf->strs_data_cap = btf->hdr->str_len; 1245919d2b1dSAndrii Nakryiko btf->strs_hash = hash; 1246919d2b1dSAndrii Nakryiko /* if BTF was created from scratch, all strings are guaranteed to be 1247919d2b1dSAndrii Nakryiko * unique and deduplicated 1248919d2b1dSAndrii Nakryiko */ 1249919d2b1dSAndrii Nakryiko btf->strs_deduped = btf->hdr->str_len <= 1; 1250919d2b1dSAndrii Nakryiko 1251919d2b1dSAndrii Nakryiko /* invalidate raw_data representation */ 1252919d2b1dSAndrii Nakryiko free(btf->raw_data); 1253919d2b1dSAndrii Nakryiko btf->raw_data = NULL; 1254919d2b1dSAndrii Nakryiko 1255919d2b1dSAndrii Nakryiko return 0; 1256919d2b1dSAndrii Nakryiko 1257919d2b1dSAndrii Nakryiko err_out: 1258919d2b1dSAndrii Nakryiko hashmap__free(hash); 1259919d2b1dSAndrii Nakryiko free(hdr); 1260919d2b1dSAndrii Nakryiko free(types); 1261919d2b1dSAndrii Nakryiko free(strs); 1262919d2b1dSAndrii Nakryiko return -ENOMEM; 1263919d2b1dSAndrii Nakryiko } 1264919d2b1dSAndrii Nakryiko 1265919d2b1dSAndrii Nakryiko static void *btf_add_str_mem(struct btf *btf, size_t add_sz) 1266919d2b1dSAndrii Nakryiko { 1267919d2b1dSAndrii Nakryiko return btf_add_mem(&btf->strs_data, &btf->strs_data_cap, 1, 1268919d2b1dSAndrii Nakryiko btf->hdr->str_len, BTF_MAX_STR_OFFSET, add_sz); 1269919d2b1dSAndrii Nakryiko } 1270919d2b1dSAndrii Nakryiko 1271919d2b1dSAndrii Nakryiko /* Find an offset in BTF string section that corresponds to a given string *s*. 1272919d2b1dSAndrii Nakryiko * Returns: 1273919d2b1dSAndrii Nakryiko * - >0 offset into string section, if string is found; 1274919d2b1dSAndrii Nakryiko * - -ENOENT, if string is not in the string section; 1275919d2b1dSAndrii Nakryiko * - <0, on any other error. 1276919d2b1dSAndrii Nakryiko */ 1277919d2b1dSAndrii Nakryiko int btf__find_str(struct btf *btf, const char *s) 1278919d2b1dSAndrii Nakryiko { 1279919d2b1dSAndrii Nakryiko long old_off, new_off, len; 1280919d2b1dSAndrii Nakryiko void *p; 1281919d2b1dSAndrii Nakryiko 1282919d2b1dSAndrii Nakryiko /* BTF needs to be in a modifiable state to build string lookup index */ 1283919d2b1dSAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1284919d2b1dSAndrii Nakryiko return -ENOMEM; 1285919d2b1dSAndrii Nakryiko 1286919d2b1dSAndrii Nakryiko /* see btf__add_str() for why we do this */ 1287919d2b1dSAndrii Nakryiko len = strlen(s) + 1; 1288919d2b1dSAndrii Nakryiko p = btf_add_str_mem(btf, len); 1289919d2b1dSAndrii Nakryiko if (!p) 1290919d2b1dSAndrii Nakryiko return -ENOMEM; 1291919d2b1dSAndrii Nakryiko 1292919d2b1dSAndrii Nakryiko new_off = btf->hdr->str_len; 1293919d2b1dSAndrii Nakryiko memcpy(p, s, len); 1294919d2b1dSAndrii Nakryiko 1295919d2b1dSAndrii Nakryiko if (hashmap__find(btf->strs_hash, (void *)new_off, (void **)&old_off)) 1296919d2b1dSAndrii Nakryiko return old_off; 1297919d2b1dSAndrii Nakryiko 1298919d2b1dSAndrii Nakryiko return -ENOENT; 1299919d2b1dSAndrii Nakryiko } 1300919d2b1dSAndrii Nakryiko 1301919d2b1dSAndrii Nakryiko /* Add a string s to the BTF string section. 1302919d2b1dSAndrii Nakryiko * Returns: 1303919d2b1dSAndrii Nakryiko * - > 0 offset into string section, on success; 1304919d2b1dSAndrii Nakryiko * - < 0, on error. 1305919d2b1dSAndrii Nakryiko */ 1306919d2b1dSAndrii Nakryiko int btf__add_str(struct btf *btf, const char *s) 1307919d2b1dSAndrii Nakryiko { 1308919d2b1dSAndrii Nakryiko long old_off, new_off, len; 1309919d2b1dSAndrii Nakryiko void *p; 1310919d2b1dSAndrii Nakryiko int err; 1311919d2b1dSAndrii Nakryiko 1312919d2b1dSAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1313919d2b1dSAndrii Nakryiko return -ENOMEM; 1314919d2b1dSAndrii Nakryiko 1315919d2b1dSAndrii Nakryiko /* Hashmap keys are always offsets within btf->strs_data, so to even 1316919d2b1dSAndrii Nakryiko * look up some string from the "outside", we need to first append it 1317919d2b1dSAndrii Nakryiko * at the end, so that it can be addressed with an offset. Luckily, 1318919d2b1dSAndrii Nakryiko * until btf->hdr->str_len is incremented, that string is just a piece 1319919d2b1dSAndrii Nakryiko * of garbage for the rest of BTF code, so no harm, no foul. On the 1320919d2b1dSAndrii Nakryiko * other hand, if the string is unique, it's already appended and 1321919d2b1dSAndrii Nakryiko * ready to be used, only a simple btf->hdr->str_len increment away. 1322919d2b1dSAndrii Nakryiko */ 1323919d2b1dSAndrii Nakryiko len = strlen(s) + 1; 1324919d2b1dSAndrii Nakryiko p = btf_add_str_mem(btf, len); 1325919d2b1dSAndrii Nakryiko if (!p) 1326919d2b1dSAndrii Nakryiko return -ENOMEM; 1327919d2b1dSAndrii Nakryiko 1328919d2b1dSAndrii Nakryiko new_off = btf->hdr->str_len; 1329919d2b1dSAndrii Nakryiko memcpy(p, s, len); 1330919d2b1dSAndrii Nakryiko 1331919d2b1dSAndrii Nakryiko /* Now attempt to add the string, but only if the string with the same 1332919d2b1dSAndrii Nakryiko * contents doesn't exist already (HASHMAP_ADD strategy). If such 1333919d2b1dSAndrii Nakryiko * string exists, we'll get its offset in old_off (that's old_key). 1334919d2b1dSAndrii Nakryiko */ 1335919d2b1dSAndrii Nakryiko err = hashmap__insert(btf->strs_hash, (void *)new_off, (void *)new_off, 1336919d2b1dSAndrii Nakryiko HASHMAP_ADD, (const void **)&old_off, NULL); 1337919d2b1dSAndrii Nakryiko if (err == -EEXIST) 1338919d2b1dSAndrii Nakryiko return old_off; /* duplicated string, return existing offset */ 1339919d2b1dSAndrii Nakryiko if (err) 1340919d2b1dSAndrii Nakryiko return err; 1341919d2b1dSAndrii Nakryiko 1342919d2b1dSAndrii Nakryiko btf->hdr->str_len += len; /* new unique string, adjust data length */ 1343919d2b1dSAndrii Nakryiko return new_off; 1344919d2b1dSAndrii Nakryiko } 1345919d2b1dSAndrii Nakryiko 1346*4a3b33f8SAndrii Nakryiko static void *btf_add_type_mem(struct btf *btf, size_t add_sz) 1347*4a3b33f8SAndrii Nakryiko { 1348*4a3b33f8SAndrii Nakryiko return btf_add_mem(&btf->types_data, &btf->types_data_cap, 1, 1349*4a3b33f8SAndrii Nakryiko btf->hdr->type_len, UINT_MAX, add_sz); 1350*4a3b33f8SAndrii Nakryiko } 1351*4a3b33f8SAndrii Nakryiko 1352*4a3b33f8SAndrii Nakryiko static __u32 btf_type_info(int kind, int vlen, int kflag) 1353*4a3b33f8SAndrii Nakryiko { 1354*4a3b33f8SAndrii Nakryiko return (kflag << 31) | (kind << 24) | vlen; 1355*4a3b33f8SAndrii Nakryiko } 1356*4a3b33f8SAndrii Nakryiko 1357*4a3b33f8SAndrii Nakryiko static void btf_type_inc_vlen(struct btf_type *t) 1358*4a3b33f8SAndrii Nakryiko { 1359*4a3b33f8SAndrii Nakryiko t->info = btf_type_info(btf_kind(t), btf_vlen(t) + 1, btf_kflag(t)); 1360*4a3b33f8SAndrii Nakryiko } 1361*4a3b33f8SAndrii Nakryiko 1362*4a3b33f8SAndrii Nakryiko /* 1363*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_INT type with: 1364*4a3b33f8SAndrii Nakryiko * - *name* - non-empty, non-NULL type name; 1365*4a3b33f8SAndrii Nakryiko * - *sz* - power-of-2 (1, 2, 4, ..) size of the type, in bytes; 1366*4a3b33f8SAndrii Nakryiko * - encoding is a combination of BTF_INT_SIGNED, BTF_INT_CHAR, BTF_INT_BOOL. 1367*4a3b33f8SAndrii Nakryiko * Returns: 1368*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1369*4a3b33f8SAndrii Nakryiko * - <0, on error. 1370*4a3b33f8SAndrii Nakryiko */ 1371*4a3b33f8SAndrii Nakryiko int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding) 1372*4a3b33f8SAndrii Nakryiko { 1373*4a3b33f8SAndrii Nakryiko struct btf_type *t; 1374*4a3b33f8SAndrii Nakryiko int sz, err, name_off; 1375*4a3b33f8SAndrii Nakryiko 1376*4a3b33f8SAndrii Nakryiko /* non-empty name */ 1377*4a3b33f8SAndrii Nakryiko if (!name || !name[0]) 1378*4a3b33f8SAndrii Nakryiko return -EINVAL; 1379*4a3b33f8SAndrii Nakryiko /* byte_sz must be power of 2 */ 1380*4a3b33f8SAndrii Nakryiko if (!byte_sz || (byte_sz & (byte_sz - 1)) || byte_sz > 16) 1381*4a3b33f8SAndrii Nakryiko return -EINVAL; 1382*4a3b33f8SAndrii Nakryiko if (encoding & ~(BTF_INT_SIGNED | BTF_INT_CHAR | BTF_INT_BOOL)) 1383*4a3b33f8SAndrii Nakryiko return -EINVAL; 1384*4a3b33f8SAndrii Nakryiko 1385*4a3b33f8SAndrii Nakryiko /* deconstruct BTF, if necessary, and invalidate raw_data */ 1386*4a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1387*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1388*4a3b33f8SAndrii Nakryiko 1389*4a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type) + sizeof(int); 1390*4a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 1391*4a3b33f8SAndrii Nakryiko if (!t) 1392*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1393*4a3b33f8SAndrii Nakryiko 1394*4a3b33f8SAndrii Nakryiko /* if something goes wrong later, we might end up with an extra string, 1395*4a3b33f8SAndrii Nakryiko * but that shouldn't be a problem, because BTF can't be constructed 1396*4a3b33f8SAndrii Nakryiko * completely anyway and will most probably be just discarded 1397*4a3b33f8SAndrii Nakryiko */ 1398*4a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 1399*4a3b33f8SAndrii Nakryiko if (name_off < 0) 1400*4a3b33f8SAndrii Nakryiko return name_off; 1401*4a3b33f8SAndrii Nakryiko 1402*4a3b33f8SAndrii Nakryiko t->name_off = name_off; 1403*4a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_INT, 0, 0); 1404*4a3b33f8SAndrii Nakryiko t->size = byte_sz; 1405*4a3b33f8SAndrii Nakryiko /* set INT info, we don't allow setting legacy bit offset/size */ 1406*4a3b33f8SAndrii Nakryiko *(__u32 *)(t + 1) = (encoding << 24) | (byte_sz * 8); 1407*4a3b33f8SAndrii Nakryiko 1408*4a3b33f8SAndrii Nakryiko err = btf_add_type_idx_entry(btf, btf->hdr->type_len); 1409*4a3b33f8SAndrii Nakryiko if (err) 1410*4a3b33f8SAndrii Nakryiko return err; 1411*4a3b33f8SAndrii Nakryiko 1412*4a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 1413*4a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 1414*4a3b33f8SAndrii Nakryiko btf->nr_types++; 1415*4a3b33f8SAndrii Nakryiko return btf->nr_types; 1416*4a3b33f8SAndrii Nakryiko } 1417*4a3b33f8SAndrii Nakryiko 1418*4a3b33f8SAndrii Nakryiko /* it's completely legal to append BTF types with type IDs pointing forward to 1419*4a3b33f8SAndrii Nakryiko * types that haven't been appended yet, so we only make sure that id looks 1420*4a3b33f8SAndrii Nakryiko * sane, we can't guarantee that ID will always be valid 1421*4a3b33f8SAndrii Nakryiko */ 1422*4a3b33f8SAndrii Nakryiko static int validate_type_id(int id) 1423*4a3b33f8SAndrii Nakryiko { 1424*4a3b33f8SAndrii Nakryiko if (id < 0 || id > BTF_MAX_NR_TYPES) 1425*4a3b33f8SAndrii Nakryiko return -EINVAL; 1426*4a3b33f8SAndrii Nakryiko return 0; 1427*4a3b33f8SAndrii Nakryiko } 1428*4a3b33f8SAndrii Nakryiko 1429*4a3b33f8SAndrii Nakryiko /* generic append function for PTR, TYPEDEF, CONST/VOLATILE/RESTRICT */ 1430*4a3b33f8SAndrii Nakryiko static int btf_add_ref_kind(struct btf *btf, int kind, const char *name, int ref_type_id) 1431*4a3b33f8SAndrii Nakryiko { 1432*4a3b33f8SAndrii Nakryiko struct btf_type *t; 1433*4a3b33f8SAndrii Nakryiko int sz, name_off = 0, err; 1434*4a3b33f8SAndrii Nakryiko 1435*4a3b33f8SAndrii Nakryiko if (validate_type_id(ref_type_id)) 1436*4a3b33f8SAndrii Nakryiko return -EINVAL; 1437*4a3b33f8SAndrii Nakryiko 1438*4a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1439*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1440*4a3b33f8SAndrii Nakryiko 1441*4a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type); 1442*4a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 1443*4a3b33f8SAndrii Nakryiko if (!t) 1444*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1445*4a3b33f8SAndrii Nakryiko 1446*4a3b33f8SAndrii Nakryiko if (name && name[0]) { 1447*4a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 1448*4a3b33f8SAndrii Nakryiko if (name_off < 0) 1449*4a3b33f8SAndrii Nakryiko return name_off; 1450*4a3b33f8SAndrii Nakryiko } 1451*4a3b33f8SAndrii Nakryiko 1452*4a3b33f8SAndrii Nakryiko t->name_off = name_off; 1453*4a3b33f8SAndrii Nakryiko t->info = btf_type_info(kind, 0, 0); 1454*4a3b33f8SAndrii Nakryiko t->type = ref_type_id; 1455*4a3b33f8SAndrii Nakryiko 1456*4a3b33f8SAndrii Nakryiko err = btf_add_type_idx_entry(btf, btf->hdr->type_len); 1457*4a3b33f8SAndrii Nakryiko if (err) 1458*4a3b33f8SAndrii Nakryiko return err; 1459*4a3b33f8SAndrii Nakryiko 1460*4a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 1461*4a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 1462*4a3b33f8SAndrii Nakryiko btf->nr_types++; 1463*4a3b33f8SAndrii Nakryiko return btf->nr_types; 1464*4a3b33f8SAndrii Nakryiko } 1465*4a3b33f8SAndrii Nakryiko 1466*4a3b33f8SAndrii Nakryiko /* 1467*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_PTR type with: 1468*4a3b33f8SAndrii Nakryiko * - *ref_type_id* - referenced type ID, it might not exist yet; 1469*4a3b33f8SAndrii Nakryiko * Returns: 1470*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1471*4a3b33f8SAndrii Nakryiko * - <0, on error. 1472*4a3b33f8SAndrii Nakryiko */ 1473*4a3b33f8SAndrii Nakryiko int btf__add_ptr(struct btf *btf, int ref_type_id) 1474*4a3b33f8SAndrii Nakryiko { 1475*4a3b33f8SAndrii Nakryiko return btf_add_ref_kind(btf, BTF_KIND_PTR, NULL, ref_type_id); 1476*4a3b33f8SAndrii Nakryiko } 1477*4a3b33f8SAndrii Nakryiko 1478*4a3b33f8SAndrii Nakryiko /* 1479*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_ARRAY type with: 1480*4a3b33f8SAndrii Nakryiko * - *index_type_id* - type ID of the type describing array index; 1481*4a3b33f8SAndrii Nakryiko * - *elem_type_id* - type ID of the type describing array element; 1482*4a3b33f8SAndrii Nakryiko * - *nr_elems* - the size of the array; 1483*4a3b33f8SAndrii Nakryiko * Returns: 1484*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1485*4a3b33f8SAndrii Nakryiko * - <0, on error. 1486*4a3b33f8SAndrii Nakryiko */ 1487*4a3b33f8SAndrii Nakryiko int btf__add_array(struct btf *btf, int index_type_id, int elem_type_id, __u32 nr_elems) 1488*4a3b33f8SAndrii Nakryiko { 1489*4a3b33f8SAndrii Nakryiko struct btf_type *t; 1490*4a3b33f8SAndrii Nakryiko struct btf_array *a; 1491*4a3b33f8SAndrii Nakryiko int sz, err; 1492*4a3b33f8SAndrii Nakryiko 1493*4a3b33f8SAndrii Nakryiko if (validate_type_id(index_type_id) || validate_type_id(elem_type_id)) 1494*4a3b33f8SAndrii Nakryiko return -EINVAL; 1495*4a3b33f8SAndrii Nakryiko 1496*4a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1497*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1498*4a3b33f8SAndrii Nakryiko 1499*4a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type) + sizeof(struct btf_array); 1500*4a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 1501*4a3b33f8SAndrii Nakryiko if (!t) 1502*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1503*4a3b33f8SAndrii Nakryiko 1504*4a3b33f8SAndrii Nakryiko t->name_off = 0; 1505*4a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_ARRAY, 0, 0); 1506*4a3b33f8SAndrii Nakryiko t->size = 0; 1507*4a3b33f8SAndrii Nakryiko 1508*4a3b33f8SAndrii Nakryiko a = btf_array(t); 1509*4a3b33f8SAndrii Nakryiko a->type = elem_type_id; 1510*4a3b33f8SAndrii Nakryiko a->index_type = index_type_id; 1511*4a3b33f8SAndrii Nakryiko a->nelems = nr_elems; 1512*4a3b33f8SAndrii Nakryiko 1513*4a3b33f8SAndrii Nakryiko err = btf_add_type_idx_entry(btf, btf->hdr->type_len); 1514*4a3b33f8SAndrii Nakryiko if (err) 1515*4a3b33f8SAndrii Nakryiko return err; 1516*4a3b33f8SAndrii Nakryiko 1517*4a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 1518*4a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 1519*4a3b33f8SAndrii Nakryiko btf->nr_types++; 1520*4a3b33f8SAndrii Nakryiko return btf->nr_types; 1521*4a3b33f8SAndrii Nakryiko } 1522*4a3b33f8SAndrii Nakryiko 1523*4a3b33f8SAndrii Nakryiko /* generic STRUCT/UNION append function */ 1524*4a3b33f8SAndrii Nakryiko static int btf_add_composite(struct btf *btf, int kind, const char *name, __u32 bytes_sz) 1525*4a3b33f8SAndrii Nakryiko { 1526*4a3b33f8SAndrii Nakryiko struct btf_type *t; 1527*4a3b33f8SAndrii Nakryiko int sz, err, name_off = 0; 1528*4a3b33f8SAndrii Nakryiko 1529*4a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1530*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1531*4a3b33f8SAndrii Nakryiko 1532*4a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type); 1533*4a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 1534*4a3b33f8SAndrii Nakryiko if (!t) 1535*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1536*4a3b33f8SAndrii Nakryiko 1537*4a3b33f8SAndrii Nakryiko if (name && name[0]) { 1538*4a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 1539*4a3b33f8SAndrii Nakryiko if (name_off < 0) 1540*4a3b33f8SAndrii Nakryiko return name_off; 1541*4a3b33f8SAndrii Nakryiko } 1542*4a3b33f8SAndrii Nakryiko 1543*4a3b33f8SAndrii Nakryiko /* start out with vlen=0 and no kflag; this will be adjusted when 1544*4a3b33f8SAndrii Nakryiko * adding each member 1545*4a3b33f8SAndrii Nakryiko */ 1546*4a3b33f8SAndrii Nakryiko t->name_off = name_off; 1547*4a3b33f8SAndrii Nakryiko t->info = btf_type_info(kind, 0, 0); 1548*4a3b33f8SAndrii Nakryiko t->size = bytes_sz; 1549*4a3b33f8SAndrii Nakryiko 1550*4a3b33f8SAndrii Nakryiko err = btf_add_type_idx_entry(btf, btf->hdr->type_len); 1551*4a3b33f8SAndrii Nakryiko if (err) 1552*4a3b33f8SAndrii Nakryiko return err; 1553*4a3b33f8SAndrii Nakryiko 1554*4a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 1555*4a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 1556*4a3b33f8SAndrii Nakryiko btf->nr_types++; 1557*4a3b33f8SAndrii Nakryiko return btf->nr_types; 1558*4a3b33f8SAndrii Nakryiko } 1559*4a3b33f8SAndrii Nakryiko 1560*4a3b33f8SAndrii Nakryiko /* 1561*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_STRUCT type with: 1562*4a3b33f8SAndrii Nakryiko * - *name* - name of the struct, can be NULL or empty for anonymous structs; 1563*4a3b33f8SAndrii Nakryiko * - *byte_sz* - size of the struct, in bytes; 1564*4a3b33f8SAndrii Nakryiko * 1565*4a3b33f8SAndrii Nakryiko * Struct initially has no fields in it. Fields can be added by 1566*4a3b33f8SAndrii Nakryiko * btf__add_field() right after btf__add_struct() succeeds. 1567*4a3b33f8SAndrii Nakryiko * 1568*4a3b33f8SAndrii Nakryiko * Returns: 1569*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1570*4a3b33f8SAndrii Nakryiko * - <0, on error. 1571*4a3b33f8SAndrii Nakryiko */ 1572*4a3b33f8SAndrii Nakryiko int btf__add_struct(struct btf *btf, const char *name, __u32 byte_sz) 1573*4a3b33f8SAndrii Nakryiko { 1574*4a3b33f8SAndrii Nakryiko return btf_add_composite(btf, BTF_KIND_STRUCT, name, byte_sz); 1575*4a3b33f8SAndrii Nakryiko } 1576*4a3b33f8SAndrii Nakryiko 1577*4a3b33f8SAndrii Nakryiko /* 1578*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_UNION type with: 1579*4a3b33f8SAndrii Nakryiko * - *name* - name of the union, can be NULL or empty for anonymous union; 1580*4a3b33f8SAndrii Nakryiko * - *byte_sz* - size of the union, in bytes; 1581*4a3b33f8SAndrii Nakryiko * 1582*4a3b33f8SAndrii Nakryiko * Union initially has no fields in it. Fields can be added by 1583*4a3b33f8SAndrii Nakryiko * btf__add_field() right after btf__add_union() succeeds. All fields 1584*4a3b33f8SAndrii Nakryiko * should have *bit_offset* of 0. 1585*4a3b33f8SAndrii Nakryiko * 1586*4a3b33f8SAndrii Nakryiko * Returns: 1587*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1588*4a3b33f8SAndrii Nakryiko * - <0, on error. 1589*4a3b33f8SAndrii Nakryiko */ 1590*4a3b33f8SAndrii Nakryiko int btf__add_union(struct btf *btf, const char *name, __u32 byte_sz) 1591*4a3b33f8SAndrii Nakryiko { 1592*4a3b33f8SAndrii Nakryiko return btf_add_composite(btf, BTF_KIND_UNION, name, byte_sz); 1593*4a3b33f8SAndrii Nakryiko } 1594*4a3b33f8SAndrii Nakryiko 1595*4a3b33f8SAndrii Nakryiko /* 1596*4a3b33f8SAndrii Nakryiko * Append new field for the current STRUCT/UNION type with: 1597*4a3b33f8SAndrii Nakryiko * - *name* - name of the field, can be NULL or empty for anonymous field; 1598*4a3b33f8SAndrii Nakryiko * - *type_id* - type ID for the type describing field type; 1599*4a3b33f8SAndrii Nakryiko * - *bit_offset* - bit offset of the start of the field within struct/union; 1600*4a3b33f8SAndrii Nakryiko * - *bit_size* - bit size of a bitfield, 0 for non-bitfield fields; 1601*4a3b33f8SAndrii Nakryiko * Returns: 1602*4a3b33f8SAndrii Nakryiko * - 0, on success; 1603*4a3b33f8SAndrii Nakryiko * - <0, on error. 1604*4a3b33f8SAndrii Nakryiko */ 1605*4a3b33f8SAndrii Nakryiko int btf__add_field(struct btf *btf, const char *name, int type_id, 1606*4a3b33f8SAndrii Nakryiko __u32 bit_offset, __u32 bit_size) 1607*4a3b33f8SAndrii Nakryiko { 1608*4a3b33f8SAndrii Nakryiko struct btf_type *t; 1609*4a3b33f8SAndrii Nakryiko struct btf_member *m; 1610*4a3b33f8SAndrii Nakryiko bool is_bitfield; 1611*4a3b33f8SAndrii Nakryiko int sz, name_off = 0; 1612*4a3b33f8SAndrii Nakryiko 1613*4a3b33f8SAndrii Nakryiko /* last type should be union/struct */ 1614*4a3b33f8SAndrii Nakryiko if (btf->nr_types == 0) 1615*4a3b33f8SAndrii Nakryiko return -EINVAL; 1616*4a3b33f8SAndrii Nakryiko t = btf_type_by_id(btf, btf->nr_types); 1617*4a3b33f8SAndrii Nakryiko if (!btf_is_composite(t)) 1618*4a3b33f8SAndrii Nakryiko return -EINVAL; 1619*4a3b33f8SAndrii Nakryiko 1620*4a3b33f8SAndrii Nakryiko if (validate_type_id(type_id)) 1621*4a3b33f8SAndrii Nakryiko return -EINVAL; 1622*4a3b33f8SAndrii Nakryiko /* best-effort bit field offset/size enforcement */ 1623*4a3b33f8SAndrii Nakryiko is_bitfield = bit_size || (bit_offset % 8 != 0); 1624*4a3b33f8SAndrii Nakryiko if (is_bitfield && (bit_size == 0 || bit_size > 255 || bit_offset > 0xffffff)) 1625*4a3b33f8SAndrii Nakryiko return -EINVAL; 1626*4a3b33f8SAndrii Nakryiko 1627*4a3b33f8SAndrii Nakryiko /* only offset 0 is allowed for unions */ 1628*4a3b33f8SAndrii Nakryiko if (btf_is_union(t) && bit_offset) 1629*4a3b33f8SAndrii Nakryiko return -EINVAL; 1630*4a3b33f8SAndrii Nakryiko 1631*4a3b33f8SAndrii Nakryiko /* decompose and invalidate raw data */ 1632*4a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1633*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1634*4a3b33f8SAndrii Nakryiko 1635*4a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_member); 1636*4a3b33f8SAndrii Nakryiko m = btf_add_type_mem(btf, sz); 1637*4a3b33f8SAndrii Nakryiko if (!m) 1638*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1639*4a3b33f8SAndrii Nakryiko 1640*4a3b33f8SAndrii Nakryiko if (name && name[0]) { 1641*4a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 1642*4a3b33f8SAndrii Nakryiko if (name_off < 0) 1643*4a3b33f8SAndrii Nakryiko return name_off; 1644*4a3b33f8SAndrii Nakryiko } 1645*4a3b33f8SAndrii Nakryiko 1646*4a3b33f8SAndrii Nakryiko m->name_off = name_off; 1647*4a3b33f8SAndrii Nakryiko m->type = type_id; 1648*4a3b33f8SAndrii Nakryiko m->offset = bit_offset | (bit_size << 24); 1649*4a3b33f8SAndrii Nakryiko 1650*4a3b33f8SAndrii Nakryiko /* btf_add_type_mem can invalidate t pointer */ 1651*4a3b33f8SAndrii Nakryiko t = btf_type_by_id(btf, btf->nr_types); 1652*4a3b33f8SAndrii Nakryiko /* update parent type's vlen and kflag */ 1653*4a3b33f8SAndrii Nakryiko t->info = btf_type_info(btf_kind(t), btf_vlen(t) + 1, is_bitfield || btf_kflag(t)); 1654*4a3b33f8SAndrii Nakryiko 1655*4a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 1656*4a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 1657*4a3b33f8SAndrii Nakryiko return 0; 1658*4a3b33f8SAndrii Nakryiko } 1659*4a3b33f8SAndrii Nakryiko 1660*4a3b33f8SAndrii Nakryiko /* 1661*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_ENUM type with: 1662*4a3b33f8SAndrii Nakryiko * - *name* - name of the enum, can be NULL or empty for anonymous enums; 1663*4a3b33f8SAndrii Nakryiko * - *byte_sz* - size of the enum, in bytes. 1664*4a3b33f8SAndrii Nakryiko * 1665*4a3b33f8SAndrii Nakryiko * Enum initially has no enum values in it (and corresponds to enum forward 1666*4a3b33f8SAndrii Nakryiko * declaration). Enumerator values can be added by btf__add_enum_value() 1667*4a3b33f8SAndrii Nakryiko * immediately after btf__add_enum() succeeds. 1668*4a3b33f8SAndrii Nakryiko * 1669*4a3b33f8SAndrii Nakryiko * Returns: 1670*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1671*4a3b33f8SAndrii Nakryiko * - <0, on error. 1672*4a3b33f8SAndrii Nakryiko */ 1673*4a3b33f8SAndrii Nakryiko int btf__add_enum(struct btf *btf, const char *name, __u32 byte_sz) 1674*4a3b33f8SAndrii Nakryiko { 1675*4a3b33f8SAndrii Nakryiko struct btf_type *t; 1676*4a3b33f8SAndrii Nakryiko int sz, err, name_off = 0; 1677*4a3b33f8SAndrii Nakryiko 1678*4a3b33f8SAndrii Nakryiko /* byte_sz must be power of 2 */ 1679*4a3b33f8SAndrii Nakryiko if (!byte_sz || (byte_sz & (byte_sz - 1)) || byte_sz > 8) 1680*4a3b33f8SAndrii Nakryiko return -EINVAL; 1681*4a3b33f8SAndrii Nakryiko 1682*4a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1683*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1684*4a3b33f8SAndrii Nakryiko 1685*4a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type); 1686*4a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 1687*4a3b33f8SAndrii Nakryiko if (!t) 1688*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1689*4a3b33f8SAndrii Nakryiko 1690*4a3b33f8SAndrii Nakryiko if (name && name[0]) { 1691*4a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 1692*4a3b33f8SAndrii Nakryiko if (name_off < 0) 1693*4a3b33f8SAndrii Nakryiko return name_off; 1694*4a3b33f8SAndrii Nakryiko } 1695*4a3b33f8SAndrii Nakryiko 1696*4a3b33f8SAndrii Nakryiko /* start out with vlen=0; it will be adjusted when adding enum values */ 1697*4a3b33f8SAndrii Nakryiko t->name_off = name_off; 1698*4a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_ENUM, 0, 0); 1699*4a3b33f8SAndrii Nakryiko t->size = byte_sz; 1700*4a3b33f8SAndrii Nakryiko 1701*4a3b33f8SAndrii Nakryiko err = btf_add_type_idx_entry(btf, btf->hdr->type_len); 1702*4a3b33f8SAndrii Nakryiko if (err) 1703*4a3b33f8SAndrii Nakryiko return err; 1704*4a3b33f8SAndrii Nakryiko 1705*4a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 1706*4a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 1707*4a3b33f8SAndrii Nakryiko btf->nr_types++; 1708*4a3b33f8SAndrii Nakryiko return btf->nr_types; 1709*4a3b33f8SAndrii Nakryiko } 1710*4a3b33f8SAndrii Nakryiko 1711*4a3b33f8SAndrii Nakryiko /* 1712*4a3b33f8SAndrii Nakryiko * Append new enum value for the current ENUM type with: 1713*4a3b33f8SAndrii Nakryiko * - *name* - name of the enumerator value, can't be NULL or empty; 1714*4a3b33f8SAndrii Nakryiko * - *value* - integer value corresponding to enum value *name*; 1715*4a3b33f8SAndrii Nakryiko * Returns: 1716*4a3b33f8SAndrii Nakryiko * - 0, on success; 1717*4a3b33f8SAndrii Nakryiko * - <0, on error. 1718*4a3b33f8SAndrii Nakryiko */ 1719*4a3b33f8SAndrii Nakryiko int btf__add_enum_value(struct btf *btf, const char *name, __s64 value) 1720*4a3b33f8SAndrii Nakryiko { 1721*4a3b33f8SAndrii Nakryiko struct btf_type *t; 1722*4a3b33f8SAndrii Nakryiko struct btf_enum *v; 1723*4a3b33f8SAndrii Nakryiko int sz, name_off; 1724*4a3b33f8SAndrii Nakryiko 1725*4a3b33f8SAndrii Nakryiko /* last type should be BTF_KIND_ENUM */ 1726*4a3b33f8SAndrii Nakryiko if (btf->nr_types == 0) 1727*4a3b33f8SAndrii Nakryiko return -EINVAL; 1728*4a3b33f8SAndrii Nakryiko t = btf_type_by_id(btf, btf->nr_types); 1729*4a3b33f8SAndrii Nakryiko if (!btf_is_enum(t)) 1730*4a3b33f8SAndrii Nakryiko return -EINVAL; 1731*4a3b33f8SAndrii Nakryiko 1732*4a3b33f8SAndrii Nakryiko /* non-empty name */ 1733*4a3b33f8SAndrii Nakryiko if (!name || !name[0]) 1734*4a3b33f8SAndrii Nakryiko return -EINVAL; 1735*4a3b33f8SAndrii Nakryiko if (value < INT_MIN || value > UINT_MAX) 1736*4a3b33f8SAndrii Nakryiko return -E2BIG; 1737*4a3b33f8SAndrii Nakryiko 1738*4a3b33f8SAndrii Nakryiko /* decompose and invalidate raw data */ 1739*4a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1740*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1741*4a3b33f8SAndrii Nakryiko 1742*4a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_enum); 1743*4a3b33f8SAndrii Nakryiko v = btf_add_type_mem(btf, sz); 1744*4a3b33f8SAndrii Nakryiko if (!v) 1745*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1746*4a3b33f8SAndrii Nakryiko 1747*4a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 1748*4a3b33f8SAndrii Nakryiko if (name_off < 0) 1749*4a3b33f8SAndrii Nakryiko return name_off; 1750*4a3b33f8SAndrii Nakryiko 1751*4a3b33f8SAndrii Nakryiko v->name_off = name_off; 1752*4a3b33f8SAndrii Nakryiko v->val = value; 1753*4a3b33f8SAndrii Nakryiko 1754*4a3b33f8SAndrii Nakryiko /* update parent type's vlen */ 1755*4a3b33f8SAndrii Nakryiko t = btf_type_by_id(btf, btf->nr_types); 1756*4a3b33f8SAndrii Nakryiko btf_type_inc_vlen(t); 1757*4a3b33f8SAndrii Nakryiko 1758*4a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 1759*4a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 1760*4a3b33f8SAndrii Nakryiko return 0; 1761*4a3b33f8SAndrii Nakryiko } 1762*4a3b33f8SAndrii Nakryiko 1763*4a3b33f8SAndrii Nakryiko /* 1764*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_FWD type with: 1765*4a3b33f8SAndrii Nakryiko * - *name*, non-empty/non-NULL name; 1766*4a3b33f8SAndrii Nakryiko * - *fwd_kind*, kind of forward declaration, one of BTF_FWD_STRUCT, 1767*4a3b33f8SAndrii Nakryiko * BTF_FWD_UNION, or BTF_FWD_ENUM; 1768*4a3b33f8SAndrii Nakryiko * Returns: 1769*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1770*4a3b33f8SAndrii Nakryiko * - <0, on error. 1771*4a3b33f8SAndrii Nakryiko */ 1772*4a3b33f8SAndrii Nakryiko int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind) 1773*4a3b33f8SAndrii Nakryiko { 1774*4a3b33f8SAndrii Nakryiko if (!name || !name[0]) 1775*4a3b33f8SAndrii Nakryiko return -EINVAL; 1776*4a3b33f8SAndrii Nakryiko 1777*4a3b33f8SAndrii Nakryiko switch (fwd_kind) { 1778*4a3b33f8SAndrii Nakryiko case BTF_FWD_STRUCT: 1779*4a3b33f8SAndrii Nakryiko case BTF_FWD_UNION: { 1780*4a3b33f8SAndrii Nakryiko struct btf_type *t; 1781*4a3b33f8SAndrii Nakryiko int id; 1782*4a3b33f8SAndrii Nakryiko 1783*4a3b33f8SAndrii Nakryiko id = btf_add_ref_kind(btf, BTF_KIND_FWD, name, 0); 1784*4a3b33f8SAndrii Nakryiko if (id <= 0) 1785*4a3b33f8SAndrii Nakryiko return id; 1786*4a3b33f8SAndrii Nakryiko t = btf_type_by_id(btf, id); 1787*4a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_FWD, 0, fwd_kind == BTF_FWD_UNION); 1788*4a3b33f8SAndrii Nakryiko return id; 1789*4a3b33f8SAndrii Nakryiko } 1790*4a3b33f8SAndrii Nakryiko case BTF_FWD_ENUM: 1791*4a3b33f8SAndrii Nakryiko /* enum forward in BTF currently is just an enum with no enum 1792*4a3b33f8SAndrii Nakryiko * values; we also assume a standard 4-byte size for it 1793*4a3b33f8SAndrii Nakryiko */ 1794*4a3b33f8SAndrii Nakryiko return btf__add_enum(btf, name, sizeof(int)); 1795*4a3b33f8SAndrii Nakryiko default: 1796*4a3b33f8SAndrii Nakryiko return -EINVAL; 1797*4a3b33f8SAndrii Nakryiko } 1798*4a3b33f8SAndrii Nakryiko } 1799*4a3b33f8SAndrii Nakryiko 1800*4a3b33f8SAndrii Nakryiko /* 1801*4a3b33f8SAndrii Nakryiko * Append new BTF_KING_TYPEDEF type with: 1802*4a3b33f8SAndrii Nakryiko * - *name*, non-empty/non-NULL name; 1803*4a3b33f8SAndrii Nakryiko * - *ref_type_id* - referenced type ID, it might not exist yet; 1804*4a3b33f8SAndrii Nakryiko * Returns: 1805*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1806*4a3b33f8SAndrii Nakryiko * - <0, on error. 1807*4a3b33f8SAndrii Nakryiko */ 1808*4a3b33f8SAndrii Nakryiko int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id) 1809*4a3b33f8SAndrii Nakryiko { 1810*4a3b33f8SAndrii Nakryiko if (!name || !name[0]) 1811*4a3b33f8SAndrii Nakryiko return -EINVAL; 1812*4a3b33f8SAndrii Nakryiko 1813*4a3b33f8SAndrii Nakryiko return btf_add_ref_kind(btf, BTF_KIND_TYPEDEF, name, ref_type_id); 1814*4a3b33f8SAndrii Nakryiko } 1815*4a3b33f8SAndrii Nakryiko 1816*4a3b33f8SAndrii Nakryiko /* 1817*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_VOLATILE type with: 1818*4a3b33f8SAndrii Nakryiko * - *ref_type_id* - referenced type ID, it might not exist yet; 1819*4a3b33f8SAndrii Nakryiko * Returns: 1820*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1821*4a3b33f8SAndrii Nakryiko * - <0, on error. 1822*4a3b33f8SAndrii Nakryiko */ 1823*4a3b33f8SAndrii Nakryiko int btf__add_volatile(struct btf *btf, int ref_type_id) 1824*4a3b33f8SAndrii Nakryiko { 1825*4a3b33f8SAndrii Nakryiko return btf_add_ref_kind(btf, BTF_KIND_VOLATILE, NULL, ref_type_id); 1826*4a3b33f8SAndrii Nakryiko } 1827*4a3b33f8SAndrii Nakryiko 1828*4a3b33f8SAndrii Nakryiko /* 1829*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_CONST type with: 1830*4a3b33f8SAndrii Nakryiko * - *ref_type_id* - referenced type ID, it might not exist yet; 1831*4a3b33f8SAndrii Nakryiko * Returns: 1832*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1833*4a3b33f8SAndrii Nakryiko * - <0, on error. 1834*4a3b33f8SAndrii Nakryiko */ 1835*4a3b33f8SAndrii Nakryiko int btf__add_const(struct btf *btf, int ref_type_id) 1836*4a3b33f8SAndrii Nakryiko { 1837*4a3b33f8SAndrii Nakryiko return btf_add_ref_kind(btf, BTF_KIND_CONST, NULL, ref_type_id); 1838*4a3b33f8SAndrii Nakryiko } 1839*4a3b33f8SAndrii Nakryiko 1840*4a3b33f8SAndrii Nakryiko /* 1841*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_RESTRICT type with: 1842*4a3b33f8SAndrii Nakryiko * - *ref_type_id* - referenced type ID, it might not exist yet; 1843*4a3b33f8SAndrii Nakryiko * Returns: 1844*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1845*4a3b33f8SAndrii Nakryiko * - <0, on error. 1846*4a3b33f8SAndrii Nakryiko */ 1847*4a3b33f8SAndrii Nakryiko int btf__add_restrict(struct btf *btf, int ref_type_id) 1848*4a3b33f8SAndrii Nakryiko { 1849*4a3b33f8SAndrii Nakryiko return btf_add_ref_kind(btf, BTF_KIND_RESTRICT, NULL, ref_type_id); 1850*4a3b33f8SAndrii Nakryiko } 1851*4a3b33f8SAndrii Nakryiko 1852*4a3b33f8SAndrii Nakryiko /* 1853*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_FUNC type with: 1854*4a3b33f8SAndrii Nakryiko * - *name*, non-empty/non-NULL name; 1855*4a3b33f8SAndrii Nakryiko * - *proto_type_id* - FUNC_PROTO's type ID, it might not exist yet; 1856*4a3b33f8SAndrii Nakryiko * Returns: 1857*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1858*4a3b33f8SAndrii Nakryiko * - <0, on error. 1859*4a3b33f8SAndrii Nakryiko */ 1860*4a3b33f8SAndrii Nakryiko int btf__add_func(struct btf *btf, const char *name, 1861*4a3b33f8SAndrii Nakryiko enum btf_func_linkage linkage, int proto_type_id) 1862*4a3b33f8SAndrii Nakryiko { 1863*4a3b33f8SAndrii Nakryiko int id; 1864*4a3b33f8SAndrii Nakryiko 1865*4a3b33f8SAndrii Nakryiko if (!name || !name[0]) 1866*4a3b33f8SAndrii Nakryiko return -EINVAL; 1867*4a3b33f8SAndrii Nakryiko if (linkage != BTF_FUNC_STATIC && linkage != BTF_FUNC_GLOBAL && 1868*4a3b33f8SAndrii Nakryiko linkage != BTF_FUNC_EXTERN) 1869*4a3b33f8SAndrii Nakryiko return -EINVAL; 1870*4a3b33f8SAndrii Nakryiko 1871*4a3b33f8SAndrii Nakryiko id = btf_add_ref_kind(btf, BTF_KIND_FUNC, name, proto_type_id); 1872*4a3b33f8SAndrii Nakryiko if (id > 0) { 1873*4a3b33f8SAndrii Nakryiko struct btf_type *t = btf_type_by_id(btf, id); 1874*4a3b33f8SAndrii Nakryiko 1875*4a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_FUNC, linkage, 0); 1876*4a3b33f8SAndrii Nakryiko } 1877*4a3b33f8SAndrii Nakryiko return id; 1878*4a3b33f8SAndrii Nakryiko } 1879*4a3b33f8SAndrii Nakryiko 1880*4a3b33f8SAndrii Nakryiko /* 1881*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_FUNC_PROTO with: 1882*4a3b33f8SAndrii Nakryiko * - *ret_type_id* - type ID for return result of a function. 1883*4a3b33f8SAndrii Nakryiko * 1884*4a3b33f8SAndrii Nakryiko * Function prototype initially has no arguments, but they can be added by 1885*4a3b33f8SAndrii Nakryiko * btf__add_func_param() one by one, immediately after 1886*4a3b33f8SAndrii Nakryiko * btf__add_func_proto() succeeded. 1887*4a3b33f8SAndrii Nakryiko * 1888*4a3b33f8SAndrii Nakryiko * Returns: 1889*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1890*4a3b33f8SAndrii Nakryiko * - <0, on error. 1891*4a3b33f8SAndrii Nakryiko */ 1892*4a3b33f8SAndrii Nakryiko int btf__add_func_proto(struct btf *btf, int ret_type_id) 1893*4a3b33f8SAndrii Nakryiko { 1894*4a3b33f8SAndrii Nakryiko struct btf_type *t; 1895*4a3b33f8SAndrii Nakryiko int sz, err; 1896*4a3b33f8SAndrii Nakryiko 1897*4a3b33f8SAndrii Nakryiko if (validate_type_id(ret_type_id)) 1898*4a3b33f8SAndrii Nakryiko return -EINVAL; 1899*4a3b33f8SAndrii Nakryiko 1900*4a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1901*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1902*4a3b33f8SAndrii Nakryiko 1903*4a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type); 1904*4a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 1905*4a3b33f8SAndrii Nakryiko if (!t) 1906*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1907*4a3b33f8SAndrii Nakryiko 1908*4a3b33f8SAndrii Nakryiko /* start out with vlen=0; this will be adjusted when adding enum 1909*4a3b33f8SAndrii Nakryiko * values, if necessary 1910*4a3b33f8SAndrii Nakryiko */ 1911*4a3b33f8SAndrii Nakryiko t->name_off = 0; 1912*4a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_FUNC_PROTO, 0, 0); 1913*4a3b33f8SAndrii Nakryiko t->type = ret_type_id; 1914*4a3b33f8SAndrii Nakryiko 1915*4a3b33f8SAndrii Nakryiko err = btf_add_type_idx_entry(btf, btf->hdr->type_len); 1916*4a3b33f8SAndrii Nakryiko if (err) 1917*4a3b33f8SAndrii Nakryiko return err; 1918*4a3b33f8SAndrii Nakryiko 1919*4a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 1920*4a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 1921*4a3b33f8SAndrii Nakryiko btf->nr_types++; 1922*4a3b33f8SAndrii Nakryiko return btf->nr_types; 1923*4a3b33f8SAndrii Nakryiko } 1924*4a3b33f8SAndrii Nakryiko 1925*4a3b33f8SAndrii Nakryiko /* 1926*4a3b33f8SAndrii Nakryiko * Append new function parameter for current FUNC_PROTO type with: 1927*4a3b33f8SAndrii Nakryiko * - *name* - parameter name, can be NULL or empty; 1928*4a3b33f8SAndrii Nakryiko * - *type_id* - type ID describing the type of the parameter. 1929*4a3b33f8SAndrii Nakryiko * Returns: 1930*4a3b33f8SAndrii Nakryiko * - 0, on success; 1931*4a3b33f8SAndrii Nakryiko * - <0, on error. 1932*4a3b33f8SAndrii Nakryiko */ 1933*4a3b33f8SAndrii Nakryiko int btf__add_func_param(struct btf *btf, const char *name, int type_id) 1934*4a3b33f8SAndrii Nakryiko { 1935*4a3b33f8SAndrii Nakryiko struct btf_type *t; 1936*4a3b33f8SAndrii Nakryiko struct btf_param *p; 1937*4a3b33f8SAndrii Nakryiko int sz, name_off = 0; 1938*4a3b33f8SAndrii Nakryiko 1939*4a3b33f8SAndrii Nakryiko if (validate_type_id(type_id)) 1940*4a3b33f8SAndrii Nakryiko return -EINVAL; 1941*4a3b33f8SAndrii Nakryiko 1942*4a3b33f8SAndrii Nakryiko /* last type should be BTF_KIND_FUNC_PROTO */ 1943*4a3b33f8SAndrii Nakryiko if (btf->nr_types == 0) 1944*4a3b33f8SAndrii Nakryiko return -EINVAL; 1945*4a3b33f8SAndrii Nakryiko t = btf_type_by_id(btf, btf->nr_types); 1946*4a3b33f8SAndrii Nakryiko if (!btf_is_func_proto(t)) 1947*4a3b33f8SAndrii Nakryiko return -EINVAL; 1948*4a3b33f8SAndrii Nakryiko 1949*4a3b33f8SAndrii Nakryiko /* decompose and invalidate raw data */ 1950*4a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 1951*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1952*4a3b33f8SAndrii Nakryiko 1953*4a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_param); 1954*4a3b33f8SAndrii Nakryiko p = btf_add_type_mem(btf, sz); 1955*4a3b33f8SAndrii Nakryiko if (!p) 1956*4a3b33f8SAndrii Nakryiko return -ENOMEM; 1957*4a3b33f8SAndrii Nakryiko 1958*4a3b33f8SAndrii Nakryiko if (name && name[0]) { 1959*4a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 1960*4a3b33f8SAndrii Nakryiko if (name_off < 0) 1961*4a3b33f8SAndrii Nakryiko return name_off; 1962*4a3b33f8SAndrii Nakryiko } 1963*4a3b33f8SAndrii Nakryiko 1964*4a3b33f8SAndrii Nakryiko p->name_off = name_off; 1965*4a3b33f8SAndrii Nakryiko p->type = type_id; 1966*4a3b33f8SAndrii Nakryiko 1967*4a3b33f8SAndrii Nakryiko /* update parent type's vlen */ 1968*4a3b33f8SAndrii Nakryiko t = btf_type_by_id(btf, btf->nr_types); 1969*4a3b33f8SAndrii Nakryiko btf_type_inc_vlen(t); 1970*4a3b33f8SAndrii Nakryiko 1971*4a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 1972*4a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 1973*4a3b33f8SAndrii Nakryiko return 0; 1974*4a3b33f8SAndrii Nakryiko } 1975*4a3b33f8SAndrii Nakryiko 1976*4a3b33f8SAndrii Nakryiko /* 1977*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_VAR type with: 1978*4a3b33f8SAndrii Nakryiko * - *name* - non-empty/non-NULL name; 1979*4a3b33f8SAndrii Nakryiko * - *linkage* - variable linkage, one of BTF_VAR_STATIC, 1980*4a3b33f8SAndrii Nakryiko * BTF_VAR_GLOBAL_ALLOCATED, or BTF_VAR_GLOBAL_EXTERN; 1981*4a3b33f8SAndrii Nakryiko * - *type_id* - type ID of the type describing the type of the variable. 1982*4a3b33f8SAndrii Nakryiko * Returns: 1983*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 1984*4a3b33f8SAndrii Nakryiko * - <0, on error. 1985*4a3b33f8SAndrii Nakryiko */ 1986*4a3b33f8SAndrii Nakryiko int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id) 1987*4a3b33f8SAndrii Nakryiko { 1988*4a3b33f8SAndrii Nakryiko struct btf_type *t; 1989*4a3b33f8SAndrii Nakryiko struct btf_var *v; 1990*4a3b33f8SAndrii Nakryiko int sz, err, name_off; 1991*4a3b33f8SAndrii Nakryiko 1992*4a3b33f8SAndrii Nakryiko /* non-empty name */ 1993*4a3b33f8SAndrii Nakryiko if (!name || !name[0]) 1994*4a3b33f8SAndrii Nakryiko return -EINVAL; 1995*4a3b33f8SAndrii Nakryiko if (linkage != BTF_VAR_STATIC && linkage != BTF_VAR_GLOBAL_ALLOCATED && 1996*4a3b33f8SAndrii Nakryiko linkage != BTF_VAR_GLOBAL_EXTERN) 1997*4a3b33f8SAndrii Nakryiko return -EINVAL; 1998*4a3b33f8SAndrii Nakryiko if (validate_type_id(type_id)) 1999*4a3b33f8SAndrii Nakryiko return -EINVAL; 2000*4a3b33f8SAndrii Nakryiko 2001*4a3b33f8SAndrii Nakryiko /* deconstruct BTF, if necessary, and invalidate raw_data */ 2002*4a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 2003*4a3b33f8SAndrii Nakryiko return -ENOMEM; 2004*4a3b33f8SAndrii Nakryiko 2005*4a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type) + sizeof(struct btf_var); 2006*4a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 2007*4a3b33f8SAndrii Nakryiko if (!t) 2008*4a3b33f8SAndrii Nakryiko return -ENOMEM; 2009*4a3b33f8SAndrii Nakryiko 2010*4a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 2011*4a3b33f8SAndrii Nakryiko if (name_off < 0) 2012*4a3b33f8SAndrii Nakryiko return name_off; 2013*4a3b33f8SAndrii Nakryiko 2014*4a3b33f8SAndrii Nakryiko t->name_off = name_off; 2015*4a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_VAR, 0, 0); 2016*4a3b33f8SAndrii Nakryiko t->type = type_id; 2017*4a3b33f8SAndrii Nakryiko 2018*4a3b33f8SAndrii Nakryiko v = btf_var(t); 2019*4a3b33f8SAndrii Nakryiko v->linkage = linkage; 2020*4a3b33f8SAndrii Nakryiko 2021*4a3b33f8SAndrii Nakryiko err = btf_add_type_idx_entry(btf, btf->hdr->type_len); 2022*4a3b33f8SAndrii Nakryiko if (err) 2023*4a3b33f8SAndrii Nakryiko return err; 2024*4a3b33f8SAndrii Nakryiko 2025*4a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 2026*4a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 2027*4a3b33f8SAndrii Nakryiko btf->nr_types++; 2028*4a3b33f8SAndrii Nakryiko return btf->nr_types; 2029*4a3b33f8SAndrii Nakryiko } 2030*4a3b33f8SAndrii Nakryiko 2031*4a3b33f8SAndrii Nakryiko /* 2032*4a3b33f8SAndrii Nakryiko * Append new BTF_KIND_DATASEC type with: 2033*4a3b33f8SAndrii Nakryiko * - *name* - non-empty/non-NULL name; 2034*4a3b33f8SAndrii Nakryiko * - *byte_sz* - data section size, in bytes. 2035*4a3b33f8SAndrii Nakryiko * 2036*4a3b33f8SAndrii Nakryiko * Data section is initially empty. Variables info can be added with 2037*4a3b33f8SAndrii Nakryiko * btf__add_datasec_var_info() calls, after btf__add_datasec() succeeds. 2038*4a3b33f8SAndrii Nakryiko * 2039*4a3b33f8SAndrii Nakryiko * Returns: 2040*4a3b33f8SAndrii Nakryiko * - >0, type ID of newly added BTF type; 2041*4a3b33f8SAndrii Nakryiko * - <0, on error. 2042*4a3b33f8SAndrii Nakryiko */ 2043*4a3b33f8SAndrii Nakryiko int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz) 2044*4a3b33f8SAndrii Nakryiko { 2045*4a3b33f8SAndrii Nakryiko struct btf_type *t; 2046*4a3b33f8SAndrii Nakryiko int sz, err, name_off; 2047*4a3b33f8SAndrii Nakryiko 2048*4a3b33f8SAndrii Nakryiko /* non-empty name */ 2049*4a3b33f8SAndrii Nakryiko if (!name || !name[0]) 2050*4a3b33f8SAndrii Nakryiko return -EINVAL; 2051*4a3b33f8SAndrii Nakryiko 2052*4a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 2053*4a3b33f8SAndrii Nakryiko return -ENOMEM; 2054*4a3b33f8SAndrii Nakryiko 2055*4a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_type); 2056*4a3b33f8SAndrii Nakryiko t = btf_add_type_mem(btf, sz); 2057*4a3b33f8SAndrii Nakryiko if (!t) 2058*4a3b33f8SAndrii Nakryiko return -ENOMEM; 2059*4a3b33f8SAndrii Nakryiko 2060*4a3b33f8SAndrii Nakryiko name_off = btf__add_str(btf, name); 2061*4a3b33f8SAndrii Nakryiko if (name_off < 0) 2062*4a3b33f8SAndrii Nakryiko return name_off; 2063*4a3b33f8SAndrii Nakryiko 2064*4a3b33f8SAndrii Nakryiko /* start with vlen=0, which will be update as var_secinfos are added */ 2065*4a3b33f8SAndrii Nakryiko t->name_off = name_off; 2066*4a3b33f8SAndrii Nakryiko t->info = btf_type_info(BTF_KIND_DATASEC, 0, 0); 2067*4a3b33f8SAndrii Nakryiko t->size = byte_sz; 2068*4a3b33f8SAndrii Nakryiko 2069*4a3b33f8SAndrii Nakryiko err = btf_add_type_idx_entry(btf, btf->hdr->type_len); 2070*4a3b33f8SAndrii Nakryiko if (err) 2071*4a3b33f8SAndrii Nakryiko return err; 2072*4a3b33f8SAndrii Nakryiko 2073*4a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 2074*4a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 2075*4a3b33f8SAndrii Nakryiko btf->nr_types++; 2076*4a3b33f8SAndrii Nakryiko return btf->nr_types; 2077*4a3b33f8SAndrii Nakryiko } 2078*4a3b33f8SAndrii Nakryiko 2079*4a3b33f8SAndrii Nakryiko /* 2080*4a3b33f8SAndrii Nakryiko * Append new data section variable information entry for current DATASEC type: 2081*4a3b33f8SAndrii Nakryiko * - *var_type_id* - type ID, describing type of the variable; 2082*4a3b33f8SAndrii Nakryiko * - *offset* - variable offset within data section, in bytes; 2083*4a3b33f8SAndrii Nakryiko * - *byte_sz* - variable size, in bytes. 2084*4a3b33f8SAndrii Nakryiko * 2085*4a3b33f8SAndrii Nakryiko * Returns: 2086*4a3b33f8SAndrii Nakryiko * - 0, on success; 2087*4a3b33f8SAndrii Nakryiko * - <0, on error. 2088*4a3b33f8SAndrii Nakryiko */ 2089*4a3b33f8SAndrii Nakryiko int btf__add_datasec_var_info(struct btf *btf, int var_type_id, __u32 offset, __u32 byte_sz) 2090*4a3b33f8SAndrii Nakryiko { 2091*4a3b33f8SAndrii Nakryiko struct btf_type *t; 2092*4a3b33f8SAndrii Nakryiko struct btf_var_secinfo *v; 2093*4a3b33f8SAndrii Nakryiko int sz; 2094*4a3b33f8SAndrii Nakryiko 2095*4a3b33f8SAndrii Nakryiko /* last type should be BTF_KIND_DATASEC */ 2096*4a3b33f8SAndrii Nakryiko if (btf->nr_types == 0) 2097*4a3b33f8SAndrii Nakryiko return -EINVAL; 2098*4a3b33f8SAndrii Nakryiko t = btf_type_by_id(btf, btf->nr_types); 2099*4a3b33f8SAndrii Nakryiko if (!btf_is_datasec(t)) 2100*4a3b33f8SAndrii Nakryiko return -EINVAL; 2101*4a3b33f8SAndrii Nakryiko 2102*4a3b33f8SAndrii Nakryiko if (validate_type_id(var_type_id)) 2103*4a3b33f8SAndrii Nakryiko return -EINVAL; 2104*4a3b33f8SAndrii Nakryiko 2105*4a3b33f8SAndrii Nakryiko /* decompose and invalidate raw data */ 2106*4a3b33f8SAndrii Nakryiko if (btf_ensure_modifiable(btf)) 2107*4a3b33f8SAndrii Nakryiko return -ENOMEM; 2108*4a3b33f8SAndrii Nakryiko 2109*4a3b33f8SAndrii Nakryiko sz = sizeof(struct btf_var_secinfo); 2110*4a3b33f8SAndrii Nakryiko v = btf_add_type_mem(btf, sz); 2111*4a3b33f8SAndrii Nakryiko if (!v) 2112*4a3b33f8SAndrii Nakryiko return -ENOMEM; 2113*4a3b33f8SAndrii Nakryiko 2114*4a3b33f8SAndrii Nakryiko v->type = var_type_id; 2115*4a3b33f8SAndrii Nakryiko v->offset = offset; 2116*4a3b33f8SAndrii Nakryiko v->size = byte_sz; 2117*4a3b33f8SAndrii Nakryiko 2118*4a3b33f8SAndrii Nakryiko /* update parent type's vlen */ 2119*4a3b33f8SAndrii Nakryiko t = btf_type_by_id(btf, btf->nr_types); 2120*4a3b33f8SAndrii Nakryiko btf_type_inc_vlen(t); 2121*4a3b33f8SAndrii Nakryiko 2122*4a3b33f8SAndrii Nakryiko btf->hdr->type_len += sz; 2123*4a3b33f8SAndrii Nakryiko btf->hdr->str_off += sz; 2124*4a3b33f8SAndrii Nakryiko return 0; 2125*4a3b33f8SAndrii Nakryiko } 2126*4a3b33f8SAndrii Nakryiko 2127ae4ab4b4SAndrii Nakryiko struct btf_ext_sec_setup_param { 21283d650141SMartin KaFai Lau __u32 off; 21293d650141SMartin KaFai Lau __u32 len; 21303d650141SMartin KaFai Lau __u32 min_rec_size; 21313d650141SMartin KaFai Lau struct btf_ext_info *ext_info; 21323d650141SMartin KaFai Lau const char *desc; 21333d650141SMartin KaFai Lau }; 21343d650141SMartin KaFai Lau 2135ae4ab4b4SAndrii Nakryiko static int btf_ext_setup_info(struct btf_ext *btf_ext, 2136ae4ab4b4SAndrii Nakryiko struct btf_ext_sec_setup_param *ext_sec) 21372993e051SYonghong Song { 21383d650141SMartin KaFai Lau const struct btf_ext_info_sec *sinfo; 21393d650141SMartin KaFai Lau struct btf_ext_info *ext_info; 2140f0187f0bSMartin KaFai Lau __u32 info_left, record_size; 2141f0187f0bSMartin KaFai Lau /* The start of the info sec (including the __u32 record_size). */ 2142ae4ab4b4SAndrii Nakryiko void *info; 2143f0187f0bSMartin KaFai Lau 21444cedc0daSAndrii Nakryiko if (ext_sec->len == 0) 21454cedc0daSAndrii Nakryiko return 0; 21464cedc0daSAndrii Nakryiko 21473d650141SMartin KaFai Lau if (ext_sec->off & 0x03) { 21488461ef8bSYonghong Song pr_debug(".BTF.ext %s section is not aligned to 4 bytes\n", 21493d650141SMartin KaFai Lau ext_sec->desc); 2150f0187f0bSMartin KaFai Lau return -EINVAL; 2151f0187f0bSMartin KaFai Lau } 2152f0187f0bSMartin KaFai Lau 2153ae4ab4b4SAndrii Nakryiko info = btf_ext->data + btf_ext->hdr->hdr_len + ext_sec->off; 2154ae4ab4b4SAndrii Nakryiko info_left = ext_sec->len; 2155ae4ab4b4SAndrii Nakryiko 2156ae4ab4b4SAndrii Nakryiko if (btf_ext->data + btf_ext->data_size < info + ext_sec->len) { 21578461ef8bSYonghong Song pr_debug("%s section (off:%u len:%u) is beyond the end of the ELF section .BTF.ext\n", 21583d650141SMartin KaFai Lau ext_sec->desc, ext_sec->off, ext_sec->len); 2159f0187f0bSMartin KaFai Lau return -EINVAL; 2160f0187f0bSMartin KaFai Lau } 2161f0187f0bSMartin KaFai Lau 21623d650141SMartin KaFai Lau /* At least a record size */ 2163f0187f0bSMartin KaFai Lau if (info_left < sizeof(__u32)) { 21648461ef8bSYonghong Song pr_debug(".BTF.ext %s record size not found\n", ext_sec->desc); 21652993e051SYonghong Song return -EINVAL; 21662993e051SYonghong Song } 21672993e051SYonghong Song 2168f0187f0bSMartin KaFai Lau /* The record size needs to meet the minimum standard */ 2169f0187f0bSMartin KaFai Lau record_size = *(__u32 *)info; 21703d650141SMartin KaFai Lau if (record_size < ext_sec->min_rec_size || 2171f0187f0bSMartin KaFai Lau record_size & 0x03) { 21728461ef8bSYonghong Song pr_debug("%s section in .BTF.ext has invalid record size %u\n", 21733d650141SMartin KaFai Lau ext_sec->desc, record_size); 21742993e051SYonghong Song return -EINVAL; 21752993e051SYonghong Song } 21762993e051SYonghong Song 2177f0187f0bSMartin KaFai Lau sinfo = info + sizeof(__u32); 2178f0187f0bSMartin KaFai Lau info_left -= sizeof(__u32); 21792993e051SYonghong Song 21803d650141SMartin KaFai Lau /* If no records, return failure now so .BTF.ext won't be used. */ 2181f0187f0bSMartin KaFai Lau if (!info_left) { 21828461ef8bSYonghong Song pr_debug("%s section in .BTF.ext has no records", ext_sec->desc); 21832993e051SYonghong Song return -EINVAL; 21842993e051SYonghong Song } 21852993e051SYonghong Song 2186f0187f0bSMartin KaFai Lau while (info_left) { 21873d650141SMartin KaFai Lau unsigned int sec_hdrlen = sizeof(struct btf_ext_info_sec); 2188f0187f0bSMartin KaFai Lau __u64 total_record_size; 2189f0187f0bSMartin KaFai Lau __u32 num_records; 2190f0187f0bSMartin KaFai Lau 2191f0187f0bSMartin KaFai Lau if (info_left < sec_hdrlen) { 21928461ef8bSYonghong Song pr_debug("%s section header is not found in .BTF.ext\n", 21933d650141SMartin KaFai Lau ext_sec->desc); 21942993e051SYonghong Song return -EINVAL; 21952993e051SYonghong Song } 21962993e051SYonghong Song 21973d650141SMartin KaFai Lau num_records = sinfo->num_info; 21982993e051SYonghong Song if (num_records == 0) { 21998461ef8bSYonghong Song pr_debug("%s section has incorrect num_records in .BTF.ext\n", 22003d650141SMartin KaFai Lau ext_sec->desc); 22012993e051SYonghong Song return -EINVAL; 22022993e051SYonghong Song } 22032993e051SYonghong Song 22042993e051SYonghong Song total_record_size = sec_hdrlen + 22052993e051SYonghong Song (__u64)num_records * record_size; 2206f0187f0bSMartin KaFai Lau if (info_left < total_record_size) { 22078461ef8bSYonghong Song pr_debug("%s section has incorrect num_records in .BTF.ext\n", 22083d650141SMartin KaFai Lau ext_sec->desc); 22092993e051SYonghong Song return -EINVAL; 22102993e051SYonghong Song } 22112993e051SYonghong Song 2212f0187f0bSMartin KaFai Lau info_left -= total_record_size; 22132993e051SYonghong Song sinfo = (void *)sinfo + total_record_size; 22142993e051SYonghong Song } 22152993e051SYonghong Song 22163d650141SMartin KaFai Lau ext_info = ext_sec->ext_info; 22173d650141SMartin KaFai Lau ext_info->len = ext_sec->len - sizeof(__u32); 22183d650141SMartin KaFai Lau ext_info->rec_size = record_size; 2219ae4ab4b4SAndrii Nakryiko ext_info->info = info + sizeof(__u32); 2220f0187f0bSMartin KaFai Lau 22212993e051SYonghong Song return 0; 22222993e051SYonghong Song } 22232993e051SYonghong Song 2224ae4ab4b4SAndrii Nakryiko static int btf_ext_setup_func_info(struct btf_ext *btf_ext) 22253d650141SMartin KaFai Lau { 2226ae4ab4b4SAndrii Nakryiko struct btf_ext_sec_setup_param param = { 2227ae4ab4b4SAndrii Nakryiko .off = btf_ext->hdr->func_info_off, 2228ae4ab4b4SAndrii Nakryiko .len = btf_ext->hdr->func_info_len, 22293d650141SMartin KaFai Lau .min_rec_size = sizeof(struct bpf_func_info_min), 22303d650141SMartin KaFai Lau .ext_info = &btf_ext->func_info, 22313d650141SMartin KaFai Lau .desc = "func_info" 22323d650141SMartin KaFai Lau }; 22333d650141SMartin KaFai Lau 2234ae4ab4b4SAndrii Nakryiko return btf_ext_setup_info(btf_ext, ¶m); 22353d650141SMartin KaFai Lau } 22363d650141SMartin KaFai Lau 2237ae4ab4b4SAndrii Nakryiko static int btf_ext_setup_line_info(struct btf_ext *btf_ext) 22383d650141SMartin KaFai Lau { 2239ae4ab4b4SAndrii Nakryiko struct btf_ext_sec_setup_param param = { 2240ae4ab4b4SAndrii Nakryiko .off = btf_ext->hdr->line_info_off, 2241ae4ab4b4SAndrii Nakryiko .len = btf_ext->hdr->line_info_len, 22423d650141SMartin KaFai Lau .min_rec_size = sizeof(struct bpf_line_info_min), 22433d650141SMartin KaFai Lau .ext_info = &btf_ext->line_info, 22443d650141SMartin KaFai Lau .desc = "line_info", 22453d650141SMartin KaFai Lau }; 22463d650141SMartin KaFai Lau 2247ae4ab4b4SAndrii Nakryiko return btf_ext_setup_info(btf_ext, ¶m); 22483d650141SMartin KaFai Lau } 22493d650141SMartin KaFai Lau 225028b93c64SAndrii Nakryiko static int btf_ext_setup_core_relos(struct btf_ext *btf_ext) 22514cedc0daSAndrii Nakryiko { 22524cedc0daSAndrii Nakryiko struct btf_ext_sec_setup_param param = { 225328b93c64SAndrii Nakryiko .off = btf_ext->hdr->core_relo_off, 225428b93c64SAndrii Nakryiko .len = btf_ext->hdr->core_relo_len, 225528b93c64SAndrii Nakryiko .min_rec_size = sizeof(struct bpf_core_relo), 225628b93c64SAndrii Nakryiko .ext_info = &btf_ext->core_relo_info, 225728b93c64SAndrii Nakryiko .desc = "core_relo", 22584cedc0daSAndrii Nakryiko }; 22594cedc0daSAndrii Nakryiko 22604cedc0daSAndrii Nakryiko return btf_ext_setup_info(btf_ext, ¶m); 22614cedc0daSAndrii Nakryiko } 22624cedc0daSAndrii Nakryiko 22638461ef8bSYonghong Song static int btf_ext_parse_hdr(__u8 *data, __u32 data_size) 22642993e051SYonghong Song { 22652993e051SYonghong Song const struct btf_ext_header *hdr = (struct btf_ext_header *)data; 22662993e051SYonghong Song 22674cedc0daSAndrii Nakryiko if (data_size < offsetofend(struct btf_ext_header, hdr_len) || 22682993e051SYonghong Song data_size < hdr->hdr_len) { 22698461ef8bSYonghong Song pr_debug("BTF.ext header not found"); 22702993e051SYonghong Song return -EINVAL; 22712993e051SYonghong Song } 22722993e051SYonghong Song 22732993e051SYonghong Song if (hdr->magic != BTF_MAGIC) { 22748461ef8bSYonghong Song pr_debug("Invalid BTF.ext magic:%x\n", hdr->magic); 22752993e051SYonghong Song return -EINVAL; 22762993e051SYonghong Song } 22772993e051SYonghong Song 22782993e051SYonghong Song if (hdr->version != BTF_VERSION) { 22798461ef8bSYonghong Song pr_debug("Unsupported BTF.ext version:%u\n", hdr->version); 22802993e051SYonghong Song return -ENOTSUP; 22812993e051SYonghong Song } 22822993e051SYonghong Song 22832993e051SYonghong Song if (hdr->flags) { 22848461ef8bSYonghong Song pr_debug("Unsupported BTF.ext flags:%x\n", hdr->flags); 22852993e051SYonghong Song return -ENOTSUP; 22862993e051SYonghong Song } 22872993e051SYonghong Song 2288f0187f0bSMartin KaFai Lau if (data_size == hdr->hdr_len) { 22898461ef8bSYonghong Song pr_debug("BTF.ext has no data\n"); 22902993e051SYonghong Song return -EINVAL; 22912993e051SYonghong Song } 22922993e051SYonghong Song 2293f0187f0bSMartin KaFai Lau return 0; 22942993e051SYonghong Song } 22952993e051SYonghong Song 22962993e051SYonghong Song void btf_ext__free(struct btf_ext *btf_ext) 22972993e051SYonghong Song { 229850450fc7SAndrii Nakryiko if (IS_ERR_OR_NULL(btf_ext)) 22992993e051SYonghong Song return; 2300ae4ab4b4SAndrii Nakryiko free(btf_ext->data); 23012993e051SYonghong Song free(btf_ext); 23022993e051SYonghong Song } 23032993e051SYonghong Song 23048461ef8bSYonghong Song struct btf_ext *btf_ext__new(__u8 *data, __u32 size) 23052993e051SYonghong Song { 23062993e051SYonghong Song struct btf_ext *btf_ext; 23072993e051SYonghong Song int err; 23082993e051SYonghong Song 23098461ef8bSYonghong Song err = btf_ext_parse_hdr(data, size); 23102993e051SYonghong Song if (err) 23112993e051SYonghong Song return ERR_PTR(err); 23122993e051SYonghong Song 23132993e051SYonghong Song btf_ext = calloc(1, sizeof(struct btf_ext)); 23142993e051SYonghong Song if (!btf_ext) 23152993e051SYonghong Song return ERR_PTR(-ENOMEM); 23162993e051SYonghong Song 2317ae4ab4b4SAndrii Nakryiko btf_ext->data_size = size; 2318ae4ab4b4SAndrii Nakryiko btf_ext->data = malloc(size); 2319ae4ab4b4SAndrii Nakryiko if (!btf_ext->data) { 2320ae4ab4b4SAndrii Nakryiko err = -ENOMEM; 2321ae4ab4b4SAndrii Nakryiko goto done; 23222993e051SYonghong Song } 2323ae4ab4b4SAndrii Nakryiko memcpy(btf_ext->data, data, size); 23242993e051SYonghong Song 23254cedc0daSAndrii Nakryiko if (btf_ext->hdr->hdr_len < 23264cedc0daSAndrii Nakryiko offsetofend(struct btf_ext_header, line_info_len)) 23274cedc0daSAndrii Nakryiko goto done; 2328ae4ab4b4SAndrii Nakryiko err = btf_ext_setup_func_info(btf_ext); 2329ae4ab4b4SAndrii Nakryiko if (err) 2330ae4ab4b4SAndrii Nakryiko goto done; 2331ae4ab4b4SAndrii Nakryiko 2332ae4ab4b4SAndrii Nakryiko err = btf_ext_setup_line_info(btf_ext); 2333ae4ab4b4SAndrii Nakryiko if (err) 2334ae4ab4b4SAndrii Nakryiko goto done; 2335ae4ab4b4SAndrii Nakryiko 233628b93c64SAndrii Nakryiko if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, core_relo_len)) 23374cedc0daSAndrii Nakryiko goto done; 233828b93c64SAndrii Nakryiko err = btf_ext_setup_core_relos(btf_ext); 23394cedc0daSAndrii Nakryiko if (err) 23404cedc0daSAndrii Nakryiko goto done; 23414cedc0daSAndrii Nakryiko 2342ae4ab4b4SAndrii Nakryiko done: 23433d650141SMartin KaFai Lau if (err) { 23443d650141SMartin KaFai Lau btf_ext__free(btf_ext); 23453d650141SMartin KaFai Lau return ERR_PTR(err); 23463d650141SMartin KaFai Lau } 23473d650141SMartin KaFai Lau 23482993e051SYonghong Song return btf_ext; 23492993e051SYonghong Song } 23502993e051SYonghong Song 2351ae4ab4b4SAndrii Nakryiko const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, __u32 *size) 2352ae4ab4b4SAndrii Nakryiko { 2353ae4ab4b4SAndrii Nakryiko *size = btf_ext->data_size; 2354ae4ab4b4SAndrii Nakryiko return btf_ext->data; 2355ae4ab4b4SAndrii Nakryiko } 2356ae4ab4b4SAndrii Nakryiko 23573d650141SMartin KaFai Lau static int btf_ext_reloc_info(const struct btf *btf, 23583d650141SMartin KaFai Lau const struct btf_ext_info *ext_info, 23592993e051SYonghong Song const char *sec_name, __u32 insns_cnt, 23603d650141SMartin KaFai Lau void **info, __u32 *cnt) 23612993e051SYonghong Song { 23623d650141SMartin KaFai Lau __u32 sec_hdrlen = sizeof(struct btf_ext_info_sec); 23633d650141SMartin KaFai Lau __u32 i, record_size, existing_len, records_len; 23643d650141SMartin KaFai Lau struct btf_ext_info_sec *sinfo; 23652993e051SYonghong Song const char *info_sec_name; 23662993e051SYonghong Song __u64 remain_len; 23672993e051SYonghong Song void *data; 23682993e051SYonghong Song 23693d650141SMartin KaFai Lau record_size = ext_info->rec_size; 23703d650141SMartin KaFai Lau sinfo = ext_info->info; 23713d650141SMartin KaFai Lau remain_len = ext_info->len; 23722993e051SYonghong Song while (remain_len > 0) { 23733d650141SMartin KaFai Lau records_len = sinfo->num_info * record_size; 23742993e051SYonghong Song info_sec_name = btf__name_by_offset(btf, sinfo->sec_name_off); 23752993e051SYonghong Song if (strcmp(info_sec_name, sec_name)) { 23762993e051SYonghong Song remain_len -= sec_hdrlen + records_len; 23772993e051SYonghong Song sinfo = (void *)sinfo + sec_hdrlen + records_len; 23782993e051SYonghong Song continue; 23792993e051SYonghong Song } 23802993e051SYonghong Song 23813d650141SMartin KaFai Lau existing_len = (*cnt) * record_size; 23823d650141SMartin KaFai Lau data = realloc(*info, existing_len + records_len); 23832993e051SYonghong Song if (!data) 23842993e051SYonghong Song return -ENOMEM; 23852993e051SYonghong Song 23863d650141SMartin KaFai Lau memcpy(data + existing_len, sinfo->data, records_len); 238784ecc1f9SMartin KaFai Lau /* adjust insn_off only, the rest data will be passed 23882993e051SYonghong Song * to the kernel. 23892993e051SYonghong Song */ 23903d650141SMartin KaFai Lau for (i = 0; i < sinfo->num_info; i++) { 23913d650141SMartin KaFai Lau __u32 *insn_off; 23922993e051SYonghong Song 23933d650141SMartin KaFai Lau insn_off = data + existing_len + (i * record_size); 23943d650141SMartin KaFai Lau *insn_off = *insn_off / sizeof(struct bpf_insn) + 23952993e051SYonghong Song insns_cnt; 23962993e051SYonghong Song } 23973d650141SMartin KaFai Lau *info = data; 23983d650141SMartin KaFai Lau *cnt += sinfo->num_info; 23992993e051SYonghong Song return 0; 24002993e051SYonghong Song } 24012993e051SYonghong Song 2402f0187f0bSMartin KaFai Lau return -ENOENT; 2403f0187f0bSMartin KaFai Lau } 2404f0187f0bSMartin KaFai Lau 2405ae4ab4b4SAndrii Nakryiko int btf_ext__reloc_func_info(const struct btf *btf, 2406ae4ab4b4SAndrii Nakryiko const struct btf_ext *btf_ext, 24073d650141SMartin KaFai Lau const char *sec_name, __u32 insns_cnt, 24083d650141SMartin KaFai Lau void **func_info, __u32 *cnt) 24093d650141SMartin KaFai Lau { 24103d650141SMartin KaFai Lau return btf_ext_reloc_info(btf, &btf_ext->func_info, sec_name, 24113d650141SMartin KaFai Lau insns_cnt, func_info, cnt); 24123d650141SMartin KaFai Lau } 24133d650141SMartin KaFai Lau 2414ae4ab4b4SAndrii Nakryiko int btf_ext__reloc_line_info(const struct btf *btf, 2415ae4ab4b4SAndrii Nakryiko const struct btf_ext *btf_ext, 24163d650141SMartin KaFai Lau const char *sec_name, __u32 insns_cnt, 24173d650141SMartin KaFai Lau void **line_info, __u32 *cnt) 24183d650141SMartin KaFai Lau { 24193d650141SMartin KaFai Lau return btf_ext_reloc_info(btf, &btf_ext->line_info, sec_name, 24203d650141SMartin KaFai Lau insns_cnt, line_info, cnt); 24213d650141SMartin KaFai Lau } 24223d650141SMartin KaFai Lau 2423f0187f0bSMartin KaFai Lau __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext) 2424f0187f0bSMartin KaFai Lau { 24253d650141SMartin KaFai Lau return btf_ext->func_info.rec_size; 24263d650141SMartin KaFai Lau } 24273d650141SMartin KaFai Lau 24283d650141SMartin KaFai Lau __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext) 24293d650141SMartin KaFai Lau { 24303d650141SMartin KaFai Lau return btf_ext->line_info.rec_size; 24312993e051SYonghong Song } 2432d5caef5bSAndrii Nakryiko 2433d5caef5bSAndrii Nakryiko struct btf_dedup; 2434d5caef5bSAndrii Nakryiko 2435d5caef5bSAndrii Nakryiko static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext, 2436d5caef5bSAndrii Nakryiko const struct btf_dedup_opts *opts); 2437d5caef5bSAndrii Nakryiko static void btf_dedup_free(struct btf_dedup *d); 2438d5caef5bSAndrii Nakryiko static int btf_dedup_strings(struct btf_dedup *d); 2439d5caef5bSAndrii Nakryiko static int btf_dedup_prim_types(struct btf_dedup *d); 2440d5caef5bSAndrii Nakryiko static int btf_dedup_struct_types(struct btf_dedup *d); 2441d5caef5bSAndrii Nakryiko static int btf_dedup_ref_types(struct btf_dedup *d); 2442d5caef5bSAndrii Nakryiko static int btf_dedup_compact_types(struct btf_dedup *d); 2443d5caef5bSAndrii Nakryiko static int btf_dedup_remap_types(struct btf_dedup *d); 2444d5caef5bSAndrii Nakryiko 2445d5caef5bSAndrii Nakryiko /* 2446d5caef5bSAndrii Nakryiko * Deduplicate BTF types and strings. 2447d5caef5bSAndrii Nakryiko * 2448d5caef5bSAndrii Nakryiko * BTF dedup algorithm takes as an input `struct btf` representing `.BTF` ELF 2449d5caef5bSAndrii Nakryiko * section with all BTF type descriptors and string data. It overwrites that 2450d5caef5bSAndrii Nakryiko * memory in-place with deduplicated types and strings without any loss of 2451d5caef5bSAndrii Nakryiko * information. If optional `struct btf_ext` representing '.BTF.ext' ELF section 2452d5caef5bSAndrii Nakryiko * is provided, all the strings referenced from .BTF.ext section are honored 2453d5caef5bSAndrii Nakryiko * and updated to point to the right offsets after deduplication. 2454d5caef5bSAndrii Nakryiko * 2455d5caef5bSAndrii Nakryiko * If function returns with error, type/string data might be garbled and should 2456d5caef5bSAndrii Nakryiko * be discarded. 2457d5caef5bSAndrii Nakryiko * 2458d5caef5bSAndrii Nakryiko * More verbose and detailed description of both problem btf_dedup is solving, 2459d5caef5bSAndrii Nakryiko * as well as solution could be found at: 2460d5caef5bSAndrii Nakryiko * https://facebookmicrosites.github.io/bpf/blog/2018/11/14/btf-enhancement.html 2461d5caef5bSAndrii Nakryiko * 2462d5caef5bSAndrii Nakryiko * Problem description and justification 2463d5caef5bSAndrii Nakryiko * ===================================== 2464d5caef5bSAndrii Nakryiko * 2465d5caef5bSAndrii Nakryiko * BTF type information is typically emitted either as a result of conversion 2466d5caef5bSAndrii Nakryiko * from DWARF to BTF or directly by compiler. In both cases, each compilation 2467d5caef5bSAndrii Nakryiko * unit contains information about a subset of all the types that are used 2468d5caef5bSAndrii Nakryiko * in an application. These subsets are frequently overlapping and contain a lot 2469d5caef5bSAndrii Nakryiko * of duplicated information when later concatenated together into a single 2470d5caef5bSAndrii Nakryiko * binary. This algorithm ensures that each unique type is represented by single 2471d5caef5bSAndrii Nakryiko * BTF type descriptor, greatly reducing resulting size of BTF data. 2472d5caef5bSAndrii Nakryiko * 2473d5caef5bSAndrii Nakryiko * Compilation unit isolation and subsequent duplication of data is not the only 2474d5caef5bSAndrii Nakryiko * problem. The same type hierarchy (e.g., struct and all the type that struct 2475d5caef5bSAndrii Nakryiko * references) in different compilation units can be represented in BTF to 2476d5caef5bSAndrii Nakryiko * various degrees of completeness (or, rather, incompleteness) due to 2477d5caef5bSAndrii Nakryiko * struct/union forward declarations. 2478d5caef5bSAndrii Nakryiko * 2479d5caef5bSAndrii Nakryiko * Let's take a look at an example, that we'll use to better understand the 2480d5caef5bSAndrii Nakryiko * problem (and solution). Suppose we have two compilation units, each using 2481d5caef5bSAndrii Nakryiko * same `struct S`, but each of them having incomplete type information about 2482d5caef5bSAndrii Nakryiko * struct's fields: 2483d5caef5bSAndrii Nakryiko * 2484d5caef5bSAndrii Nakryiko * // CU #1: 2485d5caef5bSAndrii Nakryiko * struct S; 2486d5caef5bSAndrii Nakryiko * struct A { 2487d5caef5bSAndrii Nakryiko * int a; 2488d5caef5bSAndrii Nakryiko * struct A* self; 2489d5caef5bSAndrii Nakryiko * struct S* parent; 2490d5caef5bSAndrii Nakryiko * }; 2491d5caef5bSAndrii Nakryiko * struct B; 2492d5caef5bSAndrii Nakryiko * struct S { 2493d5caef5bSAndrii Nakryiko * struct A* a_ptr; 2494d5caef5bSAndrii Nakryiko * struct B* b_ptr; 2495d5caef5bSAndrii Nakryiko * }; 2496d5caef5bSAndrii Nakryiko * 2497d5caef5bSAndrii Nakryiko * // CU #2: 2498d5caef5bSAndrii Nakryiko * struct S; 2499d5caef5bSAndrii Nakryiko * struct A; 2500d5caef5bSAndrii Nakryiko * struct B { 2501d5caef5bSAndrii Nakryiko * int b; 2502d5caef5bSAndrii Nakryiko * struct B* self; 2503d5caef5bSAndrii Nakryiko * struct S* parent; 2504d5caef5bSAndrii Nakryiko * }; 2505d5caef5bSAndrii Nakryiko * struct S { 2506d5caef5bSAndrii Nakryiko * struct A* a_ptr; 2507d5caef5bSAndrii Nakryiko * struct B* b_ptr; 2508d5caef5bSAndrii Nakryiko * }; 2509d5caef5bSAndrii Nakryiko * 2510d5caef5bSAndrii Nakryiko * In case of CU #1, BTF data will know only that `struct B` exist (but no 2511d5caef5bSAndrii Nakryiko * more), but will know the complete type information about `struct A`. While 2512d5caef5bSAndrii Nakryiko * for CU #2, it will know full type information about `struct B`, but will 2513d5caef5bSAndrii Nakryiko * only know about forward declaration of `struct A` (in BTF terms, it will 2514d5caef5bSAndrii Nakryiko * have `BTF_KIND_FWD` type descriptor with name `B`). 2515d5caef5bSAndrii Nakryiko * 2516d5caef5bSAndrii Nakryiko * This compilation unit isolation means that it's possible that there is no 2517d5caef5bSAndrii Nakryiko * single CU with complete type information describing structs `S`, `A`, and 2518d5caef5bSAndrii Nakryiko * `B`. Also, we might get tons of duplicated and redundant type information. 2519d5caef5bSAndrii Nakryiko * 2520d5caef5bSAndrii Nakryiko * Additional complication we need to keep in mind comes from the fact that 2521d5caef5bSAndrii Nakryiko * types, in general, can form graphs containing cycles, not just DAGs. 2522d5caef5bSAndrii Nakryiko * 2523d5caef5bSAndrii Nakryiko * While algorithm does deduplication, it also merges and resolves type 2524d5caef5bSAndrii Nakryiko * information (unless disabled throught `struct btf_opts`), whenever possible. 2525d5caef5bSAndrii Nakryiko * E.g., in the example above with two compilation units having partial type 2526d5caef5bSAndrii Nakryiko * information for structs `A` and `B`, the output of algorithm will emit 2527d5caef5bSAndrii Nakryiko * a single copy of each BTF type that describes structs `A`, `B`, and `S` 2528d5caef5bSAndrii Nakryiko * (as well as type information for `int` and pointers), as if they were defined 2529d5caef5bSAndrii Nakryiko * in a single compilation unit as: 2530d5caef5bSAndrii Nakryiko * 2531d5caef5bSAndrii Nakryiko * struct A { 2532d5caef5bSAndrii Nakryiko * int a; 2533d5caef5bSAndrii Nakryiko * struct A* self; 2534d5caef5bSAndrii Nakryiko * struct S* parent; 2535d5caef5bSAndrii Nakryiko * }; 2536d5caef5bSAndrii Nakryiko * struct B { 2537d5caef5bSAndrii Nakryiko * int b; 2538d5caef5bSAndrii Nakryiko * struct B* self; 2539d5caef5bSAndrii Nakryiko * struct S* parent; 2540d5caef5bSAndrii Nakryiko * }; 2541d5caef5bSAndrii Nakryiko * struct S { 2542d5caef5bSAndrii Nakryiko * struct A* a_ptr; 2543d5caef5bSAndrii Nakryiko * struct B* b_ptr; 2544d5caef5bSAndrii Nakryiko * }; 2545d5caef5bSAndrii Nakryiko * 2546d5caef5bSAndrii Nakryiko * Algorithm summary 2547d5caef5bSAndrii Nakryiko * ================= 2548d5caef5bSAndrii Nakryiko * 2549d5caef5bSAndrii Nakryiko * Algorithm completes its work in 6 separate passes: 2550d5caef5bSAndrii Nakryiko * 2551d5caef5bSAndrii Nakryiko * 1. Strings deduplication. 2552d5caef5bSAndrii Nakryiko * 2. Primitive types deduplication (int, enum, fwd). 2553d5caef5bSAndrii Nakryiko * 3. Struct/union types deduplication. 2554d5caef5bSAndrii Nakryiko * 4. Reference types deduplication (pointers, typedefs, arrays, funcs, func 2555d5caef5bSAndrii Nakryiko * protos, and const/volatile/restrict modifiers). 2556d5caef5bSAndrii Nakryiko * 5. Types compaction. 2557d5caef5bSAndrii Nakryiko * 6. Types remapping. 2558d5caef5bSAndrii Nakryiko * 2559d5caef5bSAndrii Nakryiko * Algorithm determines canonical type descriptor, which is a single 2560d5caef5bSAndrii Nakryiko * representative type for each truly unique type. This canonical type is the 2561d5caef5bSAndrii Nakryiko * one that will go into final deduplicated BTF type information. For 2562d5caef5bSAndrii Nakryiko * struct/unions, it is also the type that algorithm will merge additional type 2563d5caef5bSAndrii Nakryiko * information into (while resolving FWDs), as it discovers it from data in 2564d5caef5bSAndrii Nakryiko * other CUs. Each input BTF type eventually gets either mapped to itself, if 2565d5caef5bSAndrii Nakryiko * that type is canonical, or to some other type, if that type is equivalent 2566d5caef5bSAndrii Nakryiko * and was chosen as canonical representative. This mapping is stored in 2567d5caef5bSAndrii Nakryiko * `btf_dedup->map` array. This map is also used to record STRUCT/UNION that 2568d5caef5bSAndrii Nakryiko * FWD type got resolved to. 2569d5caef5bSAndrii Nakryiko * 2570d5caef5bSAndrii Nakryiko * To facilitate fast discovery of canonical types, we also maintain canonical 2571d5caef5bSAndrii Nakryiko * index (`btf_dedup->dedup_table`), which maps type descriptor's signature hash 2572d5caef5bSAndrii Nakryiko * (i.e., hashed kind, name, size, fields, etc) into a list of canonical types 2573d5caef5bSAndrii Nakryiko * that match that signature. With sufficiently good choice of type signature 2574d5caef5bSAndrii Nakryiko * hashing function, we can limit number of canonical types for each unique type 2575d5caef5bSAndrii Nakryiko * signature to a very small number, allowing to find canonical type for any 2576d5caef5bSAndrii Nakryiko * duplicated type very quickly. 2577d5caef5bSAndrii Nakryiko * 2578d5caef5bSAndrii Nakryiko * Struct/union deduplication is the most critical part and algorithm for 2579d5caef5bSAndrii Nakryiko * deduplicating structs/unions is described in greater details in comments for 2580d5caef5bSAndrii Nakryiko * `btf_dedup_is_equiv` function. 2581d5caef5bSAndrii Nakryiko */ 2582d5caef5bSAndrii Nakryiko int btf__dedup(struct btf *btf, struct btf_ext *btf_ext, 2583d5caef5bSAndrii Nakryiko const struct btf_dedup_opts *opts) 2584d5caef5bSAndrii Nakryiko { 2585d5caef5bSAndrii Nakryiko struct btf_dedup *d = btf_dedup_new(btf, btf_ext, opts); 2586d5caef5bSAndrii Nakryiko int err; 2587d5caef5bSAndrii Nakryiko 2588d5caef5bSAndrii Nakryiko if (IS_ERR(d)) { 2589d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_new failed: %ld", PTR_ERR(d)); 2590d5caef5bSAndrii Nakryiko return -EINVAL; 2591d5caef5bSAndrii Nakryiko } 2592d5caef5bSAndrii Nakryiko 2593919d2b1dSAndrii Nakryiko if (btf_ensure_modifiable(btf)) 2594919d2b1dSAndrii Nakryiko return -ENOMEM; 2595919d2b1dSAndrii Nakryiko 2596d5caef5bSAndrii Nakryiko err = btf_dedup_strings(d); 2597d5caef5bSAndrii Nakryiko if (err < 0) { 2598d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_strings failed:%d\n", err); 2599d5caef5bSAndrii Nakryiko goto done; 2600d5caef5bSAndrii Nakryiko } 2601d5caef5bSAndrii Nakryiko err = btf_dedup_prim_types(d); 2602d5caef5bSAndrii Nakryiko if (err < 0) { 2603d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_prim_types failed:%d\n", err); 2604d5caef5bSAndrii Nakryiko goto done; 2605d5caef5bSAndrii Nakryiko } 2606d5caef5bSAndrii Nakryiko err = btf_dedup_struct_types(d); 2607d5caef5bSAndrii Nakryiko if (err < 0) { 2608d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_struct_types failed:%d\n", err); 2609d5caef5bSAndrii Nakryiko goto done; 2610d5caef5bSAndrii Nakryiko } 2611d5caef5bSAndrii Nakryiko err = btf_dedup_ref_types(d); 2612d5caef5bSAndrii Nakryiko if (err < 0) { 2613d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_ref_types failed:%d\n", err); 2614d5caef5bSAndrii Nakryiko goto done; 2615d5caef5bSAndrii Nakryiko } 2616d5caef5bSAndrii Nakryiko err = btf_dedup_compact_types(d); 2617d5caef5bSAndrii Nakryiko if (err < 0) { 2618d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_compact_types failed:%d\n", err); 2619d5caef5bSAndrii Nakryiko goto done; 2620d5caef5bSAndrii Nakryiko } 2621d5caef5bSAndrii Nakryiko err = btf_dedup_remap_types(d); 2622d5caef5bSAndrii Nakryiko if (err < 0) { 2623d5caef5bSAndrii Nakryiko pr_debug("btf_dedup_remap_types failed:%d\n", err); 2624d5caef5bSAndrii Nakryiko goto done; 2625d5caef5bSAndrii Nakryiko } 2626d5caef5bSAndrii Nakryiko 2627d5caef5bSAndrii Nakryiko done: 2628d5caef5bSAndrii Nakryiko btf_dedup_free(d); 2629d5caef5bSAndrii Nakryiko return err; 2630d5caef5bSAndrii Nakryiko } 2631d5caef5bSAndrii Nakryiko 2632d5caef5bSAndrii Nakryiko #define BTF_UNPROCESSED_ID ((__u32)-1) 2633d5caef5bSAndrii Nakryiko #define BTF_IN_PROGRESS_ID ((__u32)-2) 2634d5caef5bSAndrii Nakryiko 2635d5caef5bSAndrii Nakryiko struct btf_dedup { 2636d5caef5bSAndrii Nakryiko /* .BTF section to be deduped in-place */ 2637d5caef5bSAndrii Nakryiko struct btf *btf; 2638d5caef5bSAndrii Nakryiko /* 2639d5caef5bSAndrii Nakryiko * Optional .BTF.ext section. When provided, any strings referenced 2640d5caef5bSAndrii Nakryiko * from it will be taken into account when deduping strings 2641d5caef5bSAndrii Nakryiko */ 2642d5caef5bSAndrii Nakryiko struct btf_ext *btf_ext; 2643d5caef5bSAndrii Nakryiko /* 2644d5caef5bSAndrii Nakryiko * This is a map from any type's signature hash to a list of possible 2645d5caef5bSAndrii Nakryiko * canonical representative type candidates. Hash collisions are 2646d5caef5bSAndrii Nakryiko * ignored, so even types of various kinds can share same list of 2647d5caef5bSAndrii Nakryiko * candidates, which is fine because we rely on subsequent 2648d5caef5bSAndrii Nakryiko * btf_xxx_equal() checks to authoritatively verify type equality. 2649d5caef5bSAndrii Nakryiko */ 26502fc3fc0bSAndrii Nakryiko struct hashmap *dedup_table; 2651d5caef5bSAndrii Nakryiko /* Canonical types map */ 2652d5caef5bSAndrii Nakryiko __u32 *map; 2653d5caef5bSAndrii Nakryiko /* Hypothetical mapping, used during type graph equivalence checks */ 2654d5caef5bSAndrii Nakryiko __u32 *hypot_map; 2655d5caef5bSAndrii Nakryiko __u32 *hypot_list; 2656d5caef5bSAndrii Nakryiko size_t hypot_cnt; 2657d5caef5bSAndrii Nakryiko size_t hypot_cap; 2658d5caef5bSAndrii Nakryiko /* Various option modifying behavior of algorithm */ 2659d5caef5bSAndrii Nakryiko struct btf_dedup_opts opts; 2660d5caef5bSAndrii Nakryiko }; 2661d5caef5bSAndrii Nakryiko 2662d5caef5bSAndrii Nakryiko struct btf_str_ptr { 2663d5caef5bSAndrii Nakryiko const char *str; 2664d5caef5bSAndrii Nakryiko __u32 new_off; 2665d5caef5bSAndrii Nakryiko bool used; 2666d5caef5bSAndrii Nakryiko }; 2667d5caef5bSAndrii Nakryiko 2668d5caef5bSAndrii Nakryiko struct btf_str_ptrs { 2669d5caef5bSAndrii Nakryiko struct btf_str_ptr *ptrs; 2670d5caef5bSAndrii Nakryiko const char *data; 2671d5caef5bSAndrii Nakryiko __u32 cnt; 2672d5caef5bSAndrii Nakryiko __u32 cap; 2673d5caef5bSAndrii Nakryiko }; 2674d5caef5bSAndrii Nakryiko 26752fc3fc0bSAndrii Nakryiko static long hash_combine(long h, long value) 2676d5caef5bSAndrii Nakryiko { 26772fc3fc0bSAndrii Nakryiko return h * 31 + value; 2678d5caef5bSAndrii Nakryiko } 2679d5caef5bSAndrii Nakryiko 26802fc3fc0bSAndrii Nakryiko #define for_each_dedup_cand(d, node, hash) \ 26812fc3fc0bSAndrii Nakryiko hashmap__for_each_key_entry(d->dedup_table, node, (void *)hash) 2682d5caef5bSAndrii Nakryiko 26832fc3fc0bSAndrii Nakryiko static int btf_dedup_table_add(struct btf_dedup *d, long hash, __u32 type_id) 2684d5caef5bSAndrii Nakryiko { 26852fc3fc0bSAndrii Nakryiko return hashmap__append(d->dedup_table, 26862fc3fc0bSAndrii Nakryiko (void *)hash, (void *)(long)type_id); 2687d5caef5bSAndrii Nakryiko } 2688d5caef5bSAndrii Nakryiko 2689d5caef5bSAndrii Nakryiko static int btf_dedup_hypot_map_add(struct btf_dedup *d, 2690d5caef5bSAndrii Nakryiko __u32 from_id, __u32 to_id) 2691d5caef5bSAndrii Nakryiko { 2692d5caef5bSAndrii Nakryiko if (d->hypot_cnt == d->hypot_cap) { 2693d5caef5bSAndrii Nakryiko __u32 *new_list; 2694d5caef5bSAndrii Nakryiko 2695fb2426adSMartin KaFai Lau d->hypot_cap += max((size_t)16, d->hypot_cap / 2); 2696029258d7SAndrii Nakryiko new_list = libbpf_reallocarray(d->hypot_list, d->hypot_cap, sizeof(__u32)); 2697d5caef5bSAndrii Nakryiko if (!new_list) 2698d5caef5bSAndrii Nakryiko return -ENOMEM; 2699d5caef5bSAndrii Nakryiko d->hypot_list = new_list; 2700d5caef5bSAndrii Nakryiko } 2701d5caef5bSAndrii Nakryiko d->hypot_list[d->hypot_cnt++] = from_id; 2702d5caef5bSAndrii Nakryiko d->hypot_map[from_id] = to_id; 2703d5caef5bSAndrii Nakryiko return 0; 2704d5caef5bSAndrii Nakryiko } 2705d5caef5bSAndrii Nakryiko 2706d5caef5bSAndrii Nakryiko static void btf_dedup_clear_hypot_map(struct btf_dedup *d) 2707d5caef5bSAndrii Nakryiko { 2708d5caef5bSAndrii Nakryiko int i; 2709d5caef5bSAndrii Nakryiko 2710d5caef5bSAndrii Nakryiko for (i = 0; i < d->hypot_cnt; i++) 2711d5caef5bSAndrii Nakryiko d->hypot_map[d->hypot_list[i]] = BTF_UNPROCESSED_ID; 2712d5caef5bSAndrii Nakryiko d->hypot_cnt = 0; 2713d5caef5bSAndrii Nakryiko } 2714d5caef5bSAndrii Nakryiko 2715d5caef5bSAndrii Nakryiko static void btf_dedup_free(struct btf_dedup *d) 2716d5caef5bSAndrii Nakryiko { 27172fc3fc0bSAndrii Nakryiko hashmap__free(d->dedup_table); 27182fc3fc0bSAndrii Nakryiko d->dedup_table = NULL; 2719d5caef5bSAndrii Nakryiko 2720d5caef5bSAndrii Nakryiko free(d->map); 2721d5caef5bSAndrii Nakryiko d->map = NULL; 2722d5caef5bSAndrii Nakryiko 2723d5caef5bSAndrii Nakryiko free(d->hypot_map); 2724d5caef5bSAndrii Nakryiko d->hypot_map = NULL; 2725d5caef5bSAndrii Nakryiko 2726d5caef5bSAndrii Nakryiko free(d->hypot_list); 2727d5caef5bSAndrii Nakryiko d->hypot_list = NULL; 2728d5caef5bSAndrii Nakryiko 2729d5caef5bSAndrii Nakryiko free(d); 2730d5caef5bSAndrii Nakryiko } 2731d5caef5bSAndrii Nakryiko 27322fc3fc0bSAndrii Nakryiko static size_t btf_dedup_identity_hash_fn(const void *key, void *ctx) 273351edf5f6SAndrii Nakryiko { 27342fc3fc0bSAndrii Nakryiko return (size_t)key; 273551edf5f6SAndrii Nakryiko } 273651edf5f6SAndrii Nakryiko 27372fc3fc0bSAndrii Nakryiko static size_t btf_dedup_collision_hash_fn(const void *key, void *ctx) 27382fc3fc0bSAndrii Nakryiko { 27392fc3fc0bSAndrii Nakryiko return 0; 27402fc3fc0bSAndrii Nakryiko } 27412fc3fc0bSAndrii Nakryiko 27422fc3fc0bSAndrii Nakryiko static bool btf_dedup_equal_fn(const void *k1, const void *k2, void *ctx) 27432fc3fc0bSAndrii Nakryiko { 27442fc3fc0bSAndrii Nakryiko return k1 == k2; 27452fc3fc0bSAndrii Nakryiko } 274651edf5f6SAndrii Nakryiko 2747d5caef5bSAndrii Nakryiko static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext, 2748d5caef5bSAndrii Nakryiko const struct btf_dedup_opts *opts) 2749d5caef5bSAndrii Nakryiko { 2750d5caef5bSAndrii Nakryiko struct btf_dedup *d = calloc(1, sizeof(struct btf_dedup)); 27512fc3fc0bSAndrii Nakryiko hashmap_hash_fn hash_fn = btf_dedup_identity_hash_fn; 2752d5caef5bSAndrii Nakryiko int i, err = 0; 2753d5caef5bSAndrii Nakryiko 2754d5caef5bSAndrii Nakryiko if (!d) 2755d5caef5bSAndrii Nakryiko return ERR_PTR(-ENOMEM); 2756d5caef5bSAndrii Nakryiko 275751edf5f6SAndrii Nakryiko d->opts.dont_resolve_fwds = opts && opts->dont_resolve_fwds; 27582fc3fc0bSAndrii Nakryiko /* dedup_table_size is now used only to force collisions in tests */ 27592fc3fc0bSAndrii Nakryiko if (opts && opts->dedup_table_size == 1) 27602fc3fc0bSAndrii Nakryiko hash_fn = btf_dedup_collision_hash_fn; 276151edf5f6SAndrii Nakryiko 2762d5caef5bSAndrii Nakryiko d->btf = btf; 2763d5caef5bSAndrii Nakryiko d->btf_ext = btf_ext; 2764d5caef5bSAndrii Nakryiko 27652fc3fc0bSAndrii Nakryiko d->dedup_table = hashmap__new(hash_fn, btf_dedup_equal_fn, NULL); 27662fc3fc0bSAndrii Nakryiko if (IS_ERR(d->dedup_table)) { 27672fc3fc0bSAndrii Nakryiko err = PTR_ERR(d->dedup_table); 27682fc3fc0bSAndrii Nakryiko d->dedup_table = NULL; 2769d5caef5bSAndrii Nakryiko goto done; 2770d5caef5bSAndrii Nakryiko } 2771d5caef5bSAndrii Nakryiko 2772d5caef5bSAndrii Nakryiko d->map = malloc(sizeof(__u32) * (1 + btf->nr_types)); 2773d5caef5bSAndrii Nakryiko if (!d->map) { 2774d5caef5bSAndrii Nakryiko err = -ENOMEM; 2775d5caef5bSAndrii Nakryiko goto done; 2776d5caef5bSAndrii Nakryiko } 2777d5caef5bSAndrii Nakryiko /* special BTF "void" type is made canonical immediately */ 2778d5caef5bSAndrii Nakryiko d->map[0] = 0; 2779189cf5a4SAndrii Nakryiko for (i = 1; i <= btf->nr_types; i++) { 2780740e69c3SAndrii Nakryiko struct btf_type *t = btf_type_by_id(d->btf, i); 2781189cf5a4SAndrii Nakryiko 2782189cf5a4SAndrii Nakryiko /* VAR and DATASEC are never deduped and are self-canonical */ 2783b03bc685SAndrii Nakryiko if (btf_is_var(t) || btf_is_datasec(t)) 2784189cf5a4SAndrii Nakryiko d->map[i] = i; 2785189cf5a4SAndrii Nakryiko else 2786d5caef5bSAndrii Nakryiko d->map[i] = BTF_UNPROCESSED_ID; 2787189cf5a4SAndrii Nakryiko } 2788d5caef5bSAndrii Nakryiko 2789d5caef5bSAndrii Nakryiko d->hypot_map = malloc(sizeof(__u32) * (1 + btf->nr_types)); 2790d5caef5bSAndrii Nakryiko if (!d->hypot_map) { 2791d5caef5bSAndrii Nakryiko err = -ENOMEM; 2792d5caef5bSAndrii Nakryiko goto done; 2793d5caef5bSAndrii Nakryiko } 2794d5caef5bSAndrii Nakryiko for (i = 0; i <= btf->nr_types; i++) 2795d5caef5bSAndrii Nakryiko d->hypot_map[i] = BTF_UNPROCESSED_ID; 2796d5caef5bSAndrii Nakryiko 2797d5caef5bSAndrii Nakryiko done: 2798d5caef5bSAndrii Nakryiko if (err) { 2799d5caef5bSAndrii Nakryiko btf_dedup_free(d); 2800d5caef5bSAndrii Nakryiko return ERR_PTR(err); 2801d5caef5bSAndrii Nakryiko } 2802d5caef5bSAndrii Nakryiko 2803d5caef5bSAndrii Nakryiko return d; 2804d5caef5bSAndrii Nakryiko } 2805d5caef5bSAndrii Nakryiko 2806d5caef5bSAndrii Nakryiko typedef int (*str_off_fn_t)(__u32 *str_off_ptr, void *ctx); 2807d5caef5bSAndrii Nakryiko 2808d5caef5bSAndrii Nakryiko /* 2809d5caef5bSAndrii Nakryiko * Iterate over all possible places in .BTF and .BTF.ext that can reference 2810d5caef5bSAndrii Nakryiko * string and pass pointer to it to a provided callback `fn`. 2811d5caef5bSAndrii Nakryiko */ 2812d5caef5bSAndrii Nakryiko static int btf_for_each_str_off(struct btf_dedup *d, str_off_fn_t fn, void *ctx) 2813d5caef5bSAndrii Nakryiko { 2814d5caef5bSAndrii Nakryiko void *line_data_cur, *line_data_end; 2815d5caef5bSAndrii Nakryiko int i, j, r, rec_size; 2816d5caef5bSAndrii Nakryiko struct btf_type *t; 2817d5caef5bSAndrii Nakryiko 2818d5caef5bSAndrii Nakryiko for (i = 1; i <= d->btf->nr_types; i++) { 2819740e69c3SAndrii Nakryiko t = btf_type_by_id(d->btf, i); 2820d5caef5bSAndrii Nakryiko r = fn(&t->name_off, ctx); 2821d5caef5bSAndrii Nakryiko if (r) 2822d5caef5bSAndrii Nakryiko return r; 2823d5caef5bSAndrii Nakryiko 2824b03bc685SAndrii Nakryiko switch (btf_kind(t)) { 2825d5caef5bSAndrii Nakryiko case BTF_KIND_STRUCT: 2826d5caef5bSAndrii Nakryiko case BTF_KIND_UNION: { 2827b03bc685SAndrii Nakryiko struct btf_member *m = btf_members(t); 2828b03bc685SAndrii Nakryiko __u16 vlen = btf_vlen(t); 2829d5caef5bSAndrii Nakryiko 2830d5caef5bSAndrii Nakryiko for (j = 0; j < vlen; j++) { 2831d5caef5bSAndrii Nakryiko r = fn(&m->name_off, ctx); 2832d5caef5bSAndrii Nakryiko if (r) 2833d5caef5bSAndrii Nakryiko return r; 2834d5caef5bSAndrii Nakryiko m++; 2835d5caef5bSAndrii Nakryiko } 2836d5caef5bSAndrii Nakryiko break; 2837d5caef5bSAndrii Nakryiko } 2838d5caef5bSAndrii Nakryiko case BTF_KIND_ENUM: { 2839b03bc685SAndrii Nakryiko struct btf_enum *m = btf_enum(t); 2840b03bc685SAndrii Nakryiko __u16 vlen = btf_vlen(t); 2841d5caef5bSAndrii Nakryiko 2842d5caef5bSAndrii Nakryiko for (j = 0; j < vlen; j++) { 2843d5caef5bSAndrii Nakryiko r = fn(&m->name_off, ctx); 2844d5caef5bSAndrii Nakryiko if (r) 2845d5caef5bSAndrii Nakryiko return r; 2846d5caef5bSAndrii Nakryiko m++; 2847d5caef5bSAndrii Nakryiko } 2848d5caef5bSAndrii Nakryiko break; 2849d5caef5bSAndrii Nakryiko } 2850d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC_PROTO: { 2851b03bc685SAndrii Nakryiko struct btf_param *m = btf_params(t); 2852b03bc685SAndrii Nakryiko __u16 vlen = btf_vlen(t); 2853d5caef5bSAndrii Nakryiko 2854d5caef5bSAndrii Nakryiko for (j = 0; j < vlen; j++) { 2855d5caef5bSAndrii Nakryiko r = fn(&m->name_off, ctx); 2856d5caef5bSAndrii Nakryiko if (r) 2857d5caef5bSAndrii Nakryiko return r; 2858d5caef5bSAndrii Nakryiko m++; 2859d5caef5bSAndrii Nakryiko } 2860d5caef5bSAndrii Nakryiko break; 2861d5caef5bSAndrii Nakryiko } 2862d5caef5bSAndrii Nakryiko default: 2863d5caef5bSAndrii Nakryiko break; 2864d5caef5bSAndrii Nakryiko } 2865d5caef5bSAndrii Nakryiko } 2866d5caef5bSAndrii Nakryiko 2867d5caef5bSAndrii Nakryiko if (!d->btf_ext) 2868d5caef5bSAndrii Nakryiko return 0; 2869d5caef5bSAndrii Nakryiko 2870d5caef5bSAndrii Nakryiko line_data_cur = d->btf_ext->line_info.info; 2871d5caef5bSAndrii Nakryiko line_data_end = d->btf_ext->line_info.info + d->btf_ext->line_info.len; 2872d5caef5bSAndrii Nakryiko rec_size = d->btf_ext->line_info.rec_size; 2873d5caef5bSAndrii Nakryiko 2874d5caef5bSAndrii Nakryiko while (line_data_cur < line_data_end) { 2875d5caef5bSAndrii Nakryiko struct btf_ext_info_sec *sec = line_data_cur; 2876d5caef5bSAndrii Nakryiko struct bpf_line_info_min *line_info; 2877d5caef5bSAndrii Nakryiko __u32 num_info = sec->num_info; 2878d5caef5bSAndrii Nakryiko 2879d5caef5bSAndrii Nakryiko r = fn(&sec->sec_name_off, ctx); 2880d5caef5bSAndrii Nakryiko if (r) 2881d5caef5bSAndrii Nakryiko return r; 2882d5caef5bSAndrii Nakryiko 2883d5caef5bSAndrii Nakryiko line_data_cur += sizeof(struct btf_ext_info_sec); 2884d5caef5bSAndrii Nakryiko for (i = 0; i < num_info; i++) { 2885d5caef5bSAndrii Nakryiko line_info = line_data_cur; 2886d5caef5bSAndrii Nakryiko r = fn(&line_info->file_name_off, ctx); 2887d5caef5bSAndrii Nakryiko if (r) 2888d5caef5bSAndrii Nakryiko return r; 2889d5caef5bSAndrii Nakryiko r = fn(&line_info->line_off, ctx); 2890d5caef5bSAndrii Nakryiko if (r) 2891d5caef5bSAndrii Nakryiko return r; 2892d5caef5bSAndrii Nakryiko line_data_cur += rec_size; 2893d5caef5bSAndrii Nakryiko } 2894d5caef5bSAndrii Nakryiko } 2895d5caef5bSAndrii Nakryiko 2896d5caef5bSAndrii Nakryiko return 0; 2897d5caef5bSAndrii Nakryiko } 2898d5caef5bSAndrii Nakryiko 2899d5caef5bSAndrii Nakryiko static int str_sort_by_content(const void *a1, const void *a2) 2900d5caef5bSAndrii Nakryiko { 2901d5caef5bSAndrii Nakryiko const struct btf_str_ptr *p1 = a1; 2902d5caef5bSAndrii Nakryiko const struct btf_str_ptr *p2 = a2; 2903d5caef5bSAndrii Nakryiko 2904d5caef5bSAndrii Nakryiko return strcmp(p1->str, p2->str); 2905d5caef5bSAndrii Nakryiko } 2906d5caef5bSAndrii Nakryiko 2907d5caef5bSAndrii Nakryiko static int str_sort_by_offset(const void *a1, const void *a2) 2908d5caef5bSAndrii Nakryiko { 2909d5caef5bSAndrii Nakryiko const struct btf_str_ptr *p1 = a1; 2910d5caef5bSAndrii Nakryiko const struct btf_str_ptr *p2 = a2; 2911d5caef5bSAndrii Nakryiko 2912d5caef5bSAndrii Nakryiko if (p1->str != p2->str) 2913d5caef5bSAndrii Nakryiko return p1->str < p2->str ? -1 : 1; 2914d5caef5bSAndrii Nakryiko return 0; 2915d5caef5bSAndrii Nakryiko } 2916d5caef5bSAndrii Nakryiko 2917d5caef5bSAndrii Nakryiko static int btf_dedup_str_ptr_cmp(const void *str_ptr, const void *pelem) 2918d5caef5bSAndrii Nakryiko { 2919d5caef5bSAndrii Nakryiko const struct btf_str_ptr *p = pelem; 2920d5caef5bSAndrii Nakryiko 2921d5caef5bSAndrii Nakryiko if (str_ptr != p->str) 2922d5caef5bSAndrii Nakryiko return (const char *)str_ptr < p->str ? -1 : 1; 2923d5caef5bSAndrii Nakryiko return 0; 2924d5caef5bSAndrii Nakryiko } 2925d5caef5bSAndrii Nakryiko 2926d5caef5bSAndrii Nakryiko static int btf_str_mark_as_used(__u32 *str_off_ptr, void *ctx) 2927d5caef5bSAndrii Nakryiko { 2928d5caef5bSAndrii Nakryiko struct btf_str_ptrs *strs; 2929d5caef5bSAndrii Nakryiko struct btf_str_ptr *s; 2930d5caef5bSAndrii Nakryiko 2931d5caef5bSAndrii Nakryiko if (*str_off_ptr == 0) 2932d5caef5bSAndrii Nakryiko return 0; 2933d5caef5bSAndrii Nakryiko 2934d5caef5bSAndrii Nakryiko strs = ctx; 2935d5caef5bSAndrii Nakryiko s = bsearch(strs->data + *str_off_ptr, strs->ptrs, strs->cnt, 2936d5caef5bSAndrii Nakryiko sizeof(struct btf_str_ptr), btf_dedup_str_ptr_cmp); 2937d5caef5bSAndrii Nakryiko if (!s) 2938d5caef5bSAndrii Nakryiko return -EINVAL; 2939d5caef5bSAndrii Nakryiko s->used = true; 2940d5caef5bSAndrii Nakryiko return 0; 2941d5caef5bSAndrii Nakryiko } 2942d5caef5bSAndrii Nakryiko 2943d5caef5bSAndrii Nakryiko static int btf_str_remap_offset(__u32 *str_off_ptr, void *ctx) 2944d5caef5bSAndrii Nakryiko { 2945d5caef5bSAndrii Nakryiko struct btf_str_ptrs *strs; 2946d5caef5bSAndrii Nakryiko struct btf_str_ptr *s; 2947d5caef5bSAndrii Nakryiko 2948d5caef5bSAndrii Nakryiko if (*str_off_ptr == 0) 2949d5caef5bSAndrii Nakryiko return 0; 2950d5caef5bSAndrii Nakryiko 2951d5caef5bSAndrii Nakryiko strs = ctx; 2952d5caef5bSAndrii Nakryiko s = bsearch(strs->data + *str_off_ptr, strs->ptrs, strs->cnt, 2953d5caef5bSAndrii Nakryiko sizeof(struct btf_str_ptr), btf_dedup_str_ptr_cmp); 2954d5caef5bSAndrii Nakryiko if (!s) 2955d5caef5bSAndrii Nakryiko return -EINVAL; 2956d5caef5bSAndrii Nakryiko *str_off_ptr = s->new_off; 2957d5caef5bSAndrii Nakryiko return 0; 2958d5caef5bSAndrii Nakryiko } 2959d5caef5bSAndrii Nakryiko 2960d5caef5bSAndrii Nakryiko /* 2961d5caef5bSAndrii Nakryiko * Dedup string and filter out those that are not referenced from either .BTF 2962d5caef5bSAndrii Nakryiko * or .BTF.ext (if provided) sections. 2963d5caef5bSAndrii Nakryiko * 2964d5caef5bSAndrii Nakryiko * This is done by building index of all strings in BTF's string section, 2965d5caef5bSAndrii Nakryiko * then iterating over all entities that can reference strings (e.g., type 2966d5caef5bSAndrii Nakryiko * names, struct field names, .BTF.ext line info, etc) and marking corresponding 2967d5caef5bSAndrii Nakryiko * strings as used. After that all used strings are deduped and compacted into 2968d5caef5bSAndrii Nakryiko * sequential blob of memory and new offsets are calculated. Then all the string 2969d5caef5bSAndrii Nakryiko * references are iterated again and rewritten using new offsets. 2970d5caef5bSAndrii Nakryiko */ 2971d5caef5bSAndrii Nakryiko static int btf_dedup_strings(struct btf_dedup *d) 2972d5caef5bSAndrii Nakryiko { 2973b8604247SAndrii Nakryiko char *start = d->btf->strs_data; 2974d5caef5bSAndrii Nakryiko char *end = start + d->btf->hdr->str_len; 2975d5caef5bSAndrii Nakryiko char *p = start, *tmp_strs = NULL; 2976d5caef5bSAndrii Nakryiko struct btf_str_ptrs strs = { 2977d5caef5bSAndrii Nakryiko .cnt = 0, 2978d5caef5bSAndrii Nakryiko .cap = 0, 2979d5caef5bSAndrii Nakryiko .ptrs = NULL, 2980d5caef5bSAndrii Nakryiko .data = start, 2981d5caef5bSAndrii Nakryiko }; 2982d5caef5bSAndrii Nakryiko int i, j, err = 0, grp_idx; 2983d5caef5bSAndrii Nakryiko bool grp_used; 2984d5caef5bSAndrii Nakryiko 2985919d2b1dSAndrii Nakryiko if (d->btf->strs_deduped) 2986919d2b1dSAndrii Nakryiko return 0; 2987919d2b1dSAndrii Nakryiko 2988d5caef5bSAndrii Nakryiko /* build index of all strings */ 2989d5caef5bSAndrii Nakryiko while (p < end) { 2990d5caef5bSAndrii Nakryiko if (strs.cnt + 1 > strs.cap) { 2991d5caef5bSAndrii Nakryiko struct btf_str_ptr *new_ptrs; 2992d5caef5bSAndrii Nakryiko 2993fb2426adSMartin KaFai Lau strs.cap += max(strs.cnt / 2, 16U); 2994029258d7SAndrii Nakryiko new_ptrs = libbpf_reallocarray(strs.ptrs, strs.cap, sizeof(strs.ptrs[0])); 2995d5caef5bSAndrii Nakryiko if (!new_ptrs) { 2996d5caef5bSAndrii Nakryiko err = -ENOMEM; 2997d5caef5bSAndrii Nakryiko goto done; 2998d5caef5bSAndrii Nakryiko } 2999d5caef5bSAndrii Nakryiko strs.ptrs = new_ptrs; 3000d5caef5bSAndrii Nakryiko } 3001d5caef5bSAndrii Nakryiko 3002d5caef5bSAndrii Nakryiko strs.ptrs[strs.cnt].str = p; 3003d5caef5bSAndrii Nakryiko strs.ptrs[strs.cnt].used = false; 3004d5caef5bSAndrii Nakryiko 3005d5caef5bSAndrii Nakryiko p += strlen(p) + 1; 3006d5caef5bSAndrii Nakryiko strs.cnt++; 3007d5caef5bSAndrii Nakryiko } 3008d5caef5bSAndrii Nakryiko 3009d5caef5bSAndrii Nakryiko /* temporary storage for deduplicated strings */ 3010d5caef5bSAndrii Nakryiko tmp_strs = malloc(d->btf->hdr->str_len); 3011d5caef5bSAndrii Nakryiko if (!tmp_strs) { 3012d5caef5bSAndrii Nakryiko err = -ENOMEM; 3013d5caef5bSAndrii Nakryiko goto done; 3014d5caef5bSAndrii Nakryiko } 3015d5caef5bSAndrii Nakryiko 3016d5caef5bSAndrii Nakryiko /* mark all used strings */ 3017d5caef5bSAndrii Nakryiko strs.ptrs[0].used = true; 3018d5caef5bSAndrii Nakryiko err = btf_for_each_str_off(d, btf_str_mark_as_used, &strs); 3019d5caef5bSAndrii Nakryiko if (err) 3020d5caef5bSAndrii Nakryiko goto done; 3021d5caef5bSAndrii Nakryiko 3022d5caef5bSAndrii Nakryiko /* sort strings by context, so that we can identify duplicates */ 3023d5caef5bSAndrii Nakryiko qsort(strs.ptrs, strs.cnt, sizeof(strs.ptrs[0]), str_sort_by_content); 3024d5caef5bSAndrii Nakryiko 3025d5caef5bSAndrii Nakryiko /* 3026d5caef5bSAndrii Nakryiko * iterate groups of equal strings and if any instance in a group was 3027d5caef5bSAndrii Nakryiko * referenced, emit single instance and remember new offset 3028d5caef5bSAndrii Nakryiko */ 3029d5caef5bSAndrii Nakryiko p = tmp_strs; 3030d5caef5bSAndrii Nakryiko grp_idx = 0; 3031d5caef5bSAndrii Nakryiko grp_used = strs.ptrs[0].used; 3032d5caef5bSAndrii Nakryiko /* iterate past end to avoid code duplication after loop */ 3033d5caef5bSAndrii Nakryiko for (i = 1; i <= strs.cnt; i++) { 3034d5caef5bSAndrii Nakryiko /* 3035d5caef5bSAndrii Nakryiko * when i == strs.cnt, we want to skip string comparison and go 3036d5caef5bSAndrii Nakryiko * straight to handling last group of strings (otherwise we'd 3037d5caef5bSAndrii Nakryiko * need to handle last group after the loop w/ duplicated code) 3038d5caef5bSAndrii Nakryiko */ 3039d5caef5bSAndrii Nakryiko if (i < strs.cnt && 3040d5caef5bSAndrii Nakryiko !strcmp(strs.ptrs[i].str, strs.ptrs[grp_idx].str)) { 3041d5caef5bSAndrii Nakryiko grp_used = grp_used || strs.ptrs[i].used; 3042d5caef5bSAndrii Nakryiko continue; 3043d5caef5bSAndrii Nakryiko } 3044d5caef5bSAndrii Nakryiko 3045d5caef5bSAndrii Nakryiko /* 3046d5caef5bSAndrii Nakryiko * this check would have been required after the loop to handle 3047d5caef5bSAndrii Nakryiko * last group of strings, but due to <= condition in a loop 3048d5caef5bSAndrii Nakryiko * we avoid that duplication 3049d5caef5bSAndrii Nakryiko */ 3050d5caef5bSAndrii Nakryiko if (grp_used) { 3051d5caef5bSAndrii Nakryiko int new_off = p - tmp_strs; 3052d5caef5bSAndrii Nakryiko __u32 len = strlen(strs.ptrs[grp_idx].str); 3053d5caef5bSAndrii Nakryiko 3054d5caef5bSAndrii Nakryiko memmove(p, strs.ptrs[grp_idx].str, len + 1); 3055d5caef5bSAndrii Nakryiko for (j = grp_idx; j < i; j++) 3056d5caef5bSAndrii Nakryiko strs.ptrs[j].new_off = new_off; 3057d5caef5bSAndrii Nakryiko p += len + 1; 3058d5caef5bSAndrii Nakryiko } 3059d5caef5bSAndrii Nakryiko 3060d5caef5bSAndrii Nakryiko if (i < strs.cnt) { 3061d5caef5bSAndrii Nakryiko grp_idx = i; 3062d5caef5bSAndrii Nakryiko grp_used = strs.ptrs[i].used; 3063d5caef5bSAndrii Nakryiko } 3064d5caef5bSAndrii Nakryiko } 3065d5caef5bSAndrii Nakryiko 3066d5caef5bSAndrii Nakryiko /* replace original strings with deduped ones */ 3067d5caef5bSAndrii Nakryiko d->btf->hdr->str_len = p - tmp_strs; 3068d5caef5bSAndrii Nakryiko memmove(start, tmp_strs, d->btf->hdr->str_len); 3069d5caef5bSAndrii Nakryiko end = start + d->btf->hdr->str_len; 3070d5caef5bSAndrii Nakryiko 3071d5caef5bSAndrii Nakryiko /* restore original order for further binary search lookups */ 3072d5caef5bSAndrii Nakryiko qsort(strs.ptrs, strs.cnt, sizeof(strs.ptrs[0]), str_sort_by_offset); 3073d5caef5bSAndrii Nakryiko 3074d5caef5bSAndrii Nakryiko /* remap string offsets */ 3075d5caef5bSAndrii Nakryiko err = btf_for_each_str_off(d, btf_str_remap_offset, &strs); 3076d5caef5bSAndrii Nakryiko if (err) 3077d5caef5bSAndrii Nakryiko goto done; 3078d5caef5bSAndrii Nakryiko 3079d5caef5bSAndrii Nakryiko d->btf->hdr->str_len = end - start; 3080919d2b1dSAndrii Nakryiko d->btf->strs_deduped = true; 3081d5caef5bSAndrii Nakryiko 3082d5caef5bSAndrii Nakryiko done: 3083d5caef5bSAndrii Nakryiko free(tmp_strs); 3084d5caef5bSAndrii Nakryiko free(strs.ptrs); 3085d5caef5bSAndrii Nakryiko return err; 3086d5caef5bSAndrii Nakryiko } 3087d5caef5bSAndrii Nakryiko 30882fc3fc0bSAndrii Nakryiko static long btf_hash_common(struct btf_type *t) 3089d5caef5bSAndrii Nakryiko { 30902fc3fc0bSAndrii Nakryiko long h; 3091d5caef5bSAndrii Nakryiko 3092d5caef5bSAndrii Nakryiko h = hash_combine(0, t->name_off); 3093d5caef5bSAndrii Nakryiko h = hash_combine(h, t->info); 3094d5caef5bSAndrii Nakryiko h = hash_combine(h, t->size); 3095d5caef5bSAndrii Nakryiko return h; 3096d5caef5bSAndrii Nakryiko } 3097d5caef5bSAndrii Nakryiko 3098d5caef5bSAndrii Nakryiko static bool btf_equal_common(struct btf_type *t1, struct btf_type *t2) 3099d5caef5bSAndrii Nakryiko { 3100d5caef5bSAndrii Nakryiko return t1->name_off == t2->name_off && 3101d5caef5bSAndrii Nakryiko t1->info == t2->info && 3102d5caef5bSAndrii Nakryiko t1->size == t2->size; 3103d5caef5bSAndrii Nakryiko } 3104d5caef5bSAndrii Nakryiko 3105d5caef5bSAndrii Nakryiko /* Calculate type signature hash of INT. */ 31062fc3fc0bSAndrii Nakryiko static long btf_hash_int(struct btf_type *t) 3107d5caef5bSAndrii Nakryiko { 3108d5caef5bSAndrii Nakryiko __u32 info = *(__u32 *)(t + 1); 31092fc3fc0bSAndrii Nakryiko long h; 3110d5caef5bSAndrii Nakryiko 3111d5caef5bSAndrii Nakryiko h = btf_hash_common(t); 3112d5caef5bSAndrii Nakryiko h = hash_combine(h, info); 3113d5caef5bSAndrii Nakryiko return h; 3114d5caef5bSAndrii Nakryiko } 3115d5caef5bSAndrii Nakryiko 3116d5caef5bSAndrii Nakryiko /* Check structural equality of two INTs. */ 3117d5caef5bSAndrii Nakryiko static bool btf_equal_int(struct btf_type *t1, struct btf_type *t2) 3118d5caef5bSAndrii Nakryiko { 3119d5caef5bSAndrii Nakryiko __u32 info1, info2; 3120d5caef5bSAndrii Nakryiko 3121d5caef5bSAndrii Nakryiko if (!btf_equal_common(t1, t2)) 3122d5caef5bSAndrii Nakryiko return false; 3123d5caef5bSAndrii Nakryiko info1 = *(__u32 *)(t1 + 1); 3124d5caef5bSAndrii Nakryiko info2 = *(__u32 *)(t2 + 1); 3125d5caef5bSAndrii Nakryiko return info1 == info2; 3126d5caef5bSAndrii Nakryiko } 3127d5caef5bSAndrii Nakryiko 3128d5caef5bSAndrii Nakryiko /* Calculate type signature hash of ENUM. */ 31292fc3fc0bSAndrii Nakryiko static long btf_hash_enum(struct btf_type *t) 3130d5caef5bSAndrii Nakryiko { 31312fc3fc0bSAndrii Nakryiko long h; 3132d5caef5bSAndrii Nakryiko 31339768095bSAndrii Nakryiko /* don't hash vlen and enum members to support enum fwd resolving */ 31349768095bSAndrii Nakryiko h = hash_combine(0, t->name_off); 31359768095bSAndrii Nakryiko h = hash_combine(h, t->info & ~0xffff); 31369768095bSAndrii Nakryiko h = hash_combine(h, t->size); 3137d5caef5bSAndrii Nakryiko return h; 3138d5caef5bSAndrii Nakryiko } 3139d5caef5bSAndrii Nakryiko 3140d5caef5bSAndrii Nakryiko /* Check structural equality of two ENUMs. */ 3141d5caef5bSAndrii Nakryiko static bool btf_equal_enum(struct btf_type *t1, struct btf_type *t2) 3142d5caef5bSAndrii Nakryiko { 3143b03bc685SAndrii Nakryiko const struct btf_enum *m1, *m2; 3144d5caef5bSAndrii Nakryiko __u16 vlen; 3145d5caef5bSAndrii Nakryiko int i; 3146d5caef5bSAndrii Nakryiko 3147d5caef5bSAndrii Nakryiko if (!btf_equal_common(t1, t2)) 3148d5caef5bSAndrii Nakryiko return false; 3149d5caef5bSAndrii Nakryiko 3150b03bc685SAndrii Nakryiko vlen = btf_vlen(t1); 3151b03bc685SAndrii Nakryiko m1 = btf_enum(t1); 3152b03bc685SAndrii Nakryiko m2 = btf_enum(t2); 3153d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3154d5caef5bSAndrii Nakryiko if (m1->name_off != m2->name_off || m1->val != m2->val) 3155d5caef5bSAndrii Nakryiko return false; 3156d5caef5bSAndrii Nakryiko m1++; 3157d5caef5bSAndrii Nakryiko m2++; 3158d5caef5bSAndrii Nakryiko } 3159d5caef5bSAndrii Nakryiko return true; 3160d5caef5bSAndrii Nakryiko } 3161d5caef5bSAndrii Nakryiko 31629768095bSAndrii Nakryiko static inline bool btf_is_enum_fwd(struct btf_type *t) 31639768095bSAndrii Nakryiko { 3164b03bc685SAndrii Nakryiko return btf_is_enum(t) && btf_vlen(t) == 0; 31659768095bSAndrii Nakryiko } 31669768095bSAndrii Nakryiko 31679768095bSAndrii Nakryiko static bool btf_compat_enum(struct btf_type *t1, struct btf_type *t2) 31689768095bSAndrii Nakryiko { 31699768095bSAndrii Nakryiko if (!btf_is_enum_fwd(t1) && !btf_is_enum_fwd(t2)) 31709768095bSAndrii Nakryiko return btf_equal_enum(t1, t2); 31719768095bSAndrii Nakryiko /* ignore vlen when comparing */ 31729768095bSAndrii Nakryiko return t1->name_off == t2->name_off && 31739768095bSAndrii Nakryiko (t1->info & ~0xffff) == (t2->info & ~0xffff) && 31749768095bSAndrii Nakryiko t1->size == t2->size; 31759768095bSAndrii Nakryiko } 31769768095bSAndrii Nakryiko 3177d5caef5bSAndrii Nakryiko /* 3178d5caef5bSAndrii Nakryiko * Calculate type signature hash of STRUCT/UNION, ignoring referenced type IDs, 3179d5caef5bSAndrii Nakryiko * as referenced type IDs equivalence is established separately during type 3180d5caef5bSAndrii Nakryiko * graph equivalence check algorithm. 3181d5caef5bSAndrii Nakryiko */ 31822fc3fc0bSAndrii Nakryiko static long btf_hash_struct(struct btf_type *t) 3183d5caef5bSAndrii Nakryiko { 3184b03bc685SAndrii Nakryiko const struct btf_member *member = btf_members(t); 3185b03bc685SAndrii Nakryiko __u32 vlen = btf_vlen(t); 31862fc3fc0bSAndrii Nakryiko long h = btf_hash_common(t); 3187d5caef5bSAndrii Nakryiko int i; 3188d5caef5bSAndrii Nakryiko 3189d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3190d5caef5bSAndrii Nakryiko h = hash_combine(h, member->name_off); 3191d5caef5bSAndrii Nakryiko h = hash_combine(h, member->offset); 3192d5caef5bSAndrii Nakryiko /* no hashing of referenced type ID, it can be unresolved yet */ 3193d5caef5bSAndrii Nakryiko member++; 3194d5caef5bSAndrii Nakryiko } 3195d5caef5bSAndrii Nakryiko return h; 3196d5caef5bSAndrii Nakryiko } 3197d5caef5bSAndrii Nakryiko 3198d5caef5bSAndrii Nakryiko /* 3199d5caef5bSAndrii Nakryiko * Check structural compatibility of two FUNC_PROTOs, ignoring referenced type 3200d5caef5bSAndrii Nakryiko * IDs. This check is performed during type graph equivalence check and 3201d5caef5bSAndrii Nakryiko * referenced types equivalence is checked separately. 3202d5caef5bSAndrii Nakryiko */ 320391097fbeSAndrii Nakryiko static bool btf_shallow_equal_struct(struct btf_type *t1, struct btf_type *t2) 3204d5caef5bSAndrii Nakryiko { 3205b03bc685SAndrii Nakryiko const struct btf_member *m1, *m2; 3206d5caef5bSAndrii Nakryiko __u16 vlen; 3207d5caef5bSAndrii Nakryiko int i; 3208d5caef5bSAndrii Nakryiko 3209d5caef5bSAndrii Nakryiko if (!btf_equal_common(t1, t2)) 3210d5caef5bSAndrii Nakryiko return false; 3211d5caef5bSAndrii Nakryiko 3212b03bc685SAndrii Nakryiko vlen = btf_vlen(t1); 3213b03bc685SAndrii Nakryiko m1 = btf_members(t1); 3214b03bc685SAndrii Nakryiko m2 = btf_members(t2); 3215d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3216d5caef5bSAndrii Nakryiko if (m1->name_off != m2->name_off || m1->offset != m2->offset) 3217d5caef5bSAndrii Nakryiko return false; 3218d5caef5bSAndrii Nakryiko m1++; 3219d5caef5bSAndrii Nakryiko m2++; 3220d5caef5bSAndrii Nakryiko } 3221d5caef5bSAndrii Nakryiko return true; 3222d5caef5bSAndrii Nakryiko } 3223d5caef5bSAndrii Nakryiko 3224d5caef5bSAndrii Nakryiko /* 3225d5caef5bSAndrii Nakryiko * Calculate type signature hash of ARRAY, including referenced type IDs, 3226d5caef5bSAndrii Nakryiko * under assumption that they were already resolved to canonical type IDs and 3227d5caef5bSAndrii Nakryiko * are not going to change. 3228d5caef5bSAndrii Nakryiko */ 32292fc3fc0bSAndrii Nakryiko static long btf_hash_array(struct btf_type *t) 3230d5caef5bSAndrii Nakryiko { 3231b03bc685SAndrii Nakryiko const struct btf_array *info = btf_array(t); 32322fc3fc0bSAndrii Nakryiko long h = btf_hash_common(t); 3233d5caef5bSAndrii Nakryiko 3234d5caef5bSAndrii Nakryiko h = hash_combine(h, info->type); 3235d5caef5bSAndrii Nakryiko h = hash_combine(h, info->index_type); 3236d5caef5bSAndrii Nakryiko h = hash_combine(h, info->nelems); 3237d5caef5bSAndrii Nakryiko return h; 3238d5caef5bSAndrii Nakryiko } 3239d5caef5bSAndrii Nakryiko 3240d5caef5bSAndrii Nakryiko /* 3241d5caef5bSAndrii Nakryiko * Check exact equality of two ARRAYs, taking into account referenced 3242d5caef5bSAndrii Nakryiko * type IDs, under assumption that they were already resolved to canonical 3243d5caef5bSAndrii Nakryiko * type IDs and are not going to change. 3244d5caef5bSAndrii Nakryiko * This function is called during reference types deduplication to compare 3245d5caef5bSAndrii Nakryiko * ARRAY to potential canonical representative. 3246d5caef5bSAndrii Nakryiko */ 3247d5caef5bSAndrii Nakryiko static bool btf_equal_array(struct btf_type *t1, struct btf_type *t2) 3248d5caef5bSAndrii Nakryiko { 3249b03bc685SAndrii Nakryiko const struct btf_array *info1, *info2; 3250d5caef5bSAndrii Nakryiko 3251d5caef5bSAndrii Nakryiko if (!btf_equal_common(t1, t2)) 3252d5caef5bSAndrii Nakryiko return false; 3253d5caef5bSAndrii Nakryiko 3254b03bc685SAndrii Nakryiko info1 = btf_array(t1); 3255b03bc685SAndrii Nakryiko info2 = btf_array(t2); 3256d5caef5bSAndrii Nakryiko return info1->type == info2->type && 3257d5caef5bSAndrii Nakryiko info1->index_type == info2->index_type && 3258d5caef5bSAndrii Nakryiko info1->nelems == info2->nelems; 3259d5caef5bSAndrii Nakryiko } 3260d5caef5bSAndrii Nakryiko 3261d5caef5bSAndrii Nakryiko /* 3262d5caef5bSAndrii Nakryiko * Check structural compatibility of two ARRAYs, ignoring referenced type 3263d5caef5bSAndrii Nakryiko * IDs. This check is performed during type graph equivalence check and 3264d5caef5bSAndrii Nakryiko * referenced types equivalence is checked separately. 3265d5caef5bSAndrii Nakryiko */ 3266d5caef5bSAndrii Nakryiko static bool btf_compat_array(struct btf_type *t1, struct btf_type *t2) 3267d5caef5bSAndrii Nakryiko { 3268d5caef5bSAndrii Nakryiko if (!btf_equal_common(t1, t2)) 3269d5caef5bSAndrii Nakryiko return false; 3270d5caef5bSAndrii Nakryiko 3271b03bc685SAndrii Nakryiko return btf_array(t1)->nelems == btf_array(t2)->nelems; 3272d5caef5bSAndrii Nakryiko } 3273d5caef5bSAndrii Nakryiko 3274d5caef5bSAndrii Nakryiko /* 3275d5caef5bSAndrii Nakryiko * Calculate type signature hash of FUNC_PROTO, including referenced type IDs, 3276d5caef5bSAndrii Nakryiko * under assumption that they were already resolved to canonical type IDs and 3277d5caef5bSAndrii Nakryiko * are not going to change. 3278d5caef5bSAndrii Nakryiko */ 32792fc3fc0bSAndrii Nakryiko static long btf_hash_fnproto(struct btf_type *t) 3280d5caef5bSAndrii Nakryiko { 3281b03bc685SAndrii Nakryiko const struct btf_param *member = btf_params(t); 3282b03bc685SAndrii Nakryiko __u16 vlen = btf_vlen(t); 32832fc3fc0bSAndrii Nakryiko long h = btf_hash_common(t); 3284d5caef5bSAndrii Nakryiko int i; 3285d5caef5bSAndrii Nakryiko 3286d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3287d5caef5bSAndrii Nakryiko h = hash_combine(h, member->name_off); 3288d5caef5bSAndrii Nakryiko h = hash_combine(h, member->type); 3289d5caef5bSAndrii Nakryiko member++; 3290d5caef5bSAndrii Nakryiko } 3291d5caef5bSAndrii Nakryiko return h; 3292d5caef5bSAndrii Nakryiko } 3293d5caef5bSAndrii Nakryiko 3294d5caef5bSAndrii Nakryiko /* 3295d5caef5bSAndrii Nakryiko * Check exact equality of two FUNC_PROTOs, taking into account referenced 3296d5caef5bSAndrii Nakryiko * type IDs, under assumption that they were already resolved to canonical 3297d5caef5bSAndrii Nakryiko * type IDs and are not going to change. 3298d5caef5bSAndrii Nakryiko * This function is called during reference types deduplication to compare 3299d5caef5bSAndrii Nakryiko * FUNC_PROTO to potential canonical representative. 3300d5caef5bSAndrii Nakryiko */ 33012fc3fc0bSAndrii Nakryiko static bool btf_equal_fnproto(struct btf_type *t1, struct btf_type *t2) 3302d5caef5bSAndrii Nakryiko { 3303b03bc685SAndrii Nakryiko const struct btf_param *m1, *m2; 3304d5caef5bSAndrii Nakryiko __u16 vlen; 3305d5caef5bSAndrii Nakryiko int i; 3306d5caef5bSAndrii Nakryiko 3307d5caef5bSAndrii Nakryiko if (!btf_equal_common(t1, t2)) 3308d5caef5bSAndrii Nakryiko return false; 3309d5caef5bSAndrii Nakryiko 3310b03bc685SAndrii Nakryiko vlen = btf_vlen(t1); 3311b03bc685SAndrii Nakryiko m1 = btf_params(t1); 3312b03bc685SAndrii Nakryiko m2 = btf_params(t2); 3313d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3314d5caef5bSAndrii Nakryiko if (m1->name_off != m2->name_off || m1->type != m2->type) 3315d5caef5bSAndrii Nakryiko return false; 3316d5caef5bSAndrii Nakryiko m1++; 3317d5caef5bSAndrii Nakryiko m2++; 3318d5caef5bSAndrii Nakryiko } 3319d5caef5bSAndrii Nakryiko return true; 3320d5caef5bSAndrii Nakryiko } 3321d5caef5bSAndrii Nakryiko 3322d5caef5bSAndrii Nakryiko /* 3323d5caef5bSAndrii Nakryiko * Check structural compatibility of two FUNC_PROTOs, ignoring referenced type 3324d5caef5bSAndrii Nakryiko * IDs. This check is performed during type graph equivalence check and 3325d5caef5bSAndrii Nakryiko * referenced types equivalence is checked separately. 3326d5caef5bSAndrii Nakryiko */ 33272fc3fc0bSAndrii Nakryiko static bool btf_compat_fnproto(struct btf_type *t1, struct btf_type *t2) 3328d5caef5bSAndrii Nakryiko { 3329b03bc685SAndrii Nakryiko const struct btf_param *m1, *m2; 3330d5caef5bSAndrii Nakryiko __u16 vlen; 3331d5caef5bSAndrii Nakryiko int i; 3332d5caef5bSAndrii Nakryiko 3333d5caef5bSAndrii Nakryiko /* skip return type ID */ 3334d5caef5bSAndrii Nakryiko if (t1->name_off != t2->name_off || t1->info != t2->info) 3335d5caef5bSAndrii Nakryiko return false; 3336d5caef5bSAndrii Nakryiko 3337b03bc685SAndrii Nakryiko vlen = btf_vlen(t1); 3338b03bc685SAndrii Nakryiko m1 = btf_params(t1); 3339b03bc685SAndrii Nakryiko m2 = btf_params(t2); 3340d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3341d5caef5bSAndrii Nakryiko if (m1->name_off != m2->name_off) 3342d5caef5bSAndrii Nakryiko return false; 3343d5caef5bSAndrii Nakryiko m1++; 3344d5caef5bSAndrii Nakryiko m2++; 3345d5caef5bSAndrii Nakryiko } 3346d5caef5bSAndrii Nakryiko return true; 3347d5caef5bSAndrii Nakryiko } 3348d5caef5bSAndrii Nakryiko 3349d5caef5bSAndrii Nakryiko /* 3350d5caef5bSAndrii Nakryiko * Deduplicate primitive types, that can't reference other types, by calculating 3351d5caef5bSAndrii Nakryiko * their type signature hash and comparing them with any possible canonical 3352d5caef5bSAndrii Nakryiko * candidate. If no canonical candidate matches, type itself is marked as 3353d5caef5bSAndrii Nakryiko * canonical and is added into `btf_dedup->dedup_table` as another candidate. 3354d5caef5bSAndrii Nakryiko */ 3355d5caef5bSAndrii Nakryiko static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id) 3356d5caef5bSAndrii Nakryiko { 3357740e69c3SAndrii Nakryiko struct btf_type *t = btf_type_by_id(d->btf, type_id); 33582fc3fc0bSAndrii Nakryiko struct hashmap_entry *hash_entry; 3359d5caef5bSAndrii Nakryiko struct btf_type *cand; 3360d5caef5bSAndrii Nakryiko /* if we don't find equivalent type, then we are canonical */ 3361d5caef5bSAndrii Nakryiko __u32 new_id = type_id; 33622fc3fc0bSAndrii Nakryiko __u32 cand_id; 33632fc3fc0bSAndrii Nakryiko long h; 3364d5caef5bSAndrii Nakryiko 3365b03bc685SAndrii Nakryiko switch (btf_kind(t)) { 3366d5caef5bSAndrii Nakryiko case BTF_KIND_CONST: 3367d5caef5bSAndrii Nakryiko case BTF_KIND_VOLATILE: 3368d5caef5bSAndrii Nakryiko case BTF_KIND_RESTRICT: 3369d5caef5bSAndrii Nakryiko case BTF_KIND_PTR: 3370d5caef5bSAndrii Nakryiko case BTF_KIND_TYPEDEF: 3371d5caef5bSAndrii Nakryiko case BTF_KIND_ARRAY: 3372d5caef5bSAndrii Nakryiko case BTF_KIND_STRUCT: 3373d5caef5bSAndrii Nakryiko case BTF_KIND_UNION: 3374d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC: 3375d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC_PROTO: 3376189cf5a4SAndrii Nakryiko case BTF_KIND_VAR: 3377189cf5a4SAndrii Nakryiko case BTF_KIND_DATASEC: 3378d5caef5bSAndrii Nakryiko return 0; 3379d5caef5bSAndrii Nakryiko 3380d5caef5bSAndrii Nakryiko case BTF_KIND_INT: 3381d5caef5bSAndrii Nakryiko h = btf_hash_int(t); 33822fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 33832fc3fc0bSAndrii Nakryiko cand_id = (__u32)(long)hash_entry->value; 3384740e69c3SAndrii Nakryiko cand = btf_type_by_id(d->btf, cand_id); 3385d5caef5bSAndrii Nakryiko if (btf_equal_int(t, cand)) { 33862fc3fc0bSAndrii Nakryiko new_id = cand_id; 3387d5caef5bSAndrii Nakryiko break; 3388d5caef5bSAndrii Nakryiko } 3389d5caef5bSAndrii Nakryiko } 3390d5caef5bSAndrii Nakryiko break; 3391d5caef5bSAndrii Nakryiko 3392d5caef5bSAndrii Nakryiko case BTF_KIND_ENUM: 3393d5caef5bSAndrii Nakryiko h = btf_hash_enum(t); 33942fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 33952fc3fc0bSAndrii Nakryiko cand_id = (__u32)(long)hash_entry->value; 3396740e69c3SAndrii Nakryiko cand = btf_type_by_id(d->btf, cand_id); 3397d5caef5bSAndrii Nakryiko if (btf_equal_enum(t, cand)) { 33982fc3fc0bSAndrii Nakryiko new_id = cand_id; 3399d5caef5bSAndrii Nakryiko break; 3400d5caef5bSAndrii Nakryiko } 34019768095bSAndrii Nakryiko if (d->opts.dont_resolve_fwds) 34029768095bSAndrii Nakryiko continue; 34039768095bSAndrii Nakryiko if (btf_compat_enum(t, cand)) { 34049768095bSAndrii Nakryiko if (btf_is_enum_fwd(t)) { 34059768095bSAndrii Nakryiko /* resolve fwd to full enum */ 34062fc3fc0bSAndrii Nakryiko new_id = cand_id; 34079768095bSAndrii Nakryiko break; 34089768095bSAndrii Nakryiko } 34099768095bSAndrii Nakryiko /* resolve canonical enum fwd to full enum */ 34102fc3fc0bSAndrii Nakryiko d->map[cand_id] = type_id; 34119768095bSAndrii Nakryiko } 3412d5caef5bSAndrii Nakryiko } 3413d5caef5bSAndrii Nakryiko break; 3414d5caef5bSAndrii Nakryiko 3415d5caef5bSAndrii Nakryiko case BTF_KIND_FWD: 3416d5caef5bSAndrii Nakryiko h = btf_hash_common(t); 34172fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 34182fc3fc0bSAndrii Nakryiko cand_id = (__u32)(long)hash_entry->value; 3419740e69c3SAndrii Nakryiko cand = btf_type_by_id(d->btf, cand_id); 3420d5caef5bSAndrii Nakryiko if (btf_equal_common(t, cand)) { 34212fc3fc0bSAndrii Nakryiko new_id = cand_id; 3422d5caef5bSAndrii Nakryiko break; 3423d5caef5bSAndrii Nakryiko } 3424d5caef5bSAndrii Nakryiko } 3425d5caef5bSAndrii Nakryiko break; 3426d5caef5bSAndrii Nakryiko 3427d5caef5bSAndrii Nakryiko default: 3428d5caef5bSAndrii Nakryiko return -EINVAL; 3429d5caef5bSAndrii Nakryiko } 3430d5caef5bSAndrii Nakryiko 3431d5caef5bSAndrii Nakryiko d->map[type_id] = new_id; 3432d5caef5bSAndrii Nakryiko if (type_id == new_id && btf_dedup_table_add(d, h, type_id)) 3433d5caef5bSAndrii Nakryiko return -ENOMEM; 3434d5caef5bSAndrii Nakryiko 3435d5caef5bSAndrii Nakryiko return 0; 3436d5caef5bSAndrii Nakryiko } 3437d5caef5bSAndrii Nakryiko 3438d5caef5bSAndrii Nakryiko static int btf_dedup_prim_types(struct btf_dedup *d) 3439d5caef5bSAndrii Nakryiko { 3440d5caef5bSAndrii Nakryiko int i, err; 3441d5caef5bSAndrii Nakryiko 3442d5caef5bSAndrii Nakryiko for (i = 1; i <= d->btf->nr_types; i++) { 3443d5caef5bSAndrii Nakryiko err = btf_dedup_prim_type(d, i); 3444d5caef5bSAndrii Nakryiko if (err) 3445d5caef5bSAndrii Nakryiko return err; 3446d5caef5bSAndrii Nakryiko } 3447d5caef5bSAndrii Nakryiko return 0; 3448d5caef5bSAndrii Nakryiko } 3449d5caef5bSAndrii Nakryiko 3450d5caef5bSAndrii Nakryiko /* 3451d5caef5bSAndrii Nakryiko * Check whether type is already mapped into canonical one (could be to itself). 3452d5caef5bSAndrii Nakryiko */ 3453d5caef5bSAndrii Nakryiko static inline bool is_type_mapped(struct btf_dedup *d, uint32_t type_id) 3454d5caef5bSAndrii Nakryiko { 34555aab392cSAndrii Nakryiko return d->map[type_id] <= BTF_MAX_NR_TYPES; 3456d5caef5bSAndrii Nakryiko } 3457d5caef5bSAndrii Nakryiko 3458d5caef5bSAndrii Nakryiko /* 3459d5caef5bSAndrii Nakryiko * Resolve type ID into its canonical type ID, if any; otherwise return original 3460d5caef5bSAndrii Nakryiko * type ID. If type is FWD and is resolved into STRUCT/UNION already, follow 3461d5caef5bSAndrii Nakryiko * STRUCT/UNION link and resolve it into canonical type ID as well. 3462d5caef5bSAndrii Nakryiko */ 3463d5caef5bSAndrii Nakryiko static inline __u32 resolve_type_id(struct btf_dedup *d, __u32 type_id) 3464d5caef5bSAndrii Nakryiko { 3465d5caef5bSAndrii Nakryiko while (is_type_mapped(d, type_id) && d->map[type_id] != type_id) 3466d5caef5bSAndrii Nakryiko type_id = d->map[type_id]; 3467d5caef5bSAndrii Nakryiko return type_id; 3468d5caef5bSAndrii Nakryiko } 3469d5caef5bSAndrii Nakryiko 3470d5caef5bSAndrii Nakryiko /* 3471d5caef5bSAndrii Nakryiko * Resolve FWD to underlying STRUCT/UNION, if any; otherwise return original 3472d5caef5bSAndrii Nakryiko * type ID. 3473d5caef5bSAndrii Nakryiko */ 3474d5caef5bSAndrii Nakryiko static uint32_t resolve_fwd_id(struct btf_dedup *d, uint32_t type_id) 3475d5caef5bSAndrii Nakryiko { 3476d5caef5bSAndrii Nakryiko __u32 orig_type_id = type_id; 3477d5caef5bSAndrii Nakryiko 3478740e69c3SAndrii Nakryiko if (!btf_is_fwd(btf__type_by_id(d->btf, type_id))) 3479d5caef5bSAndrii Nakryiko return type_id; 3480d5caef5bSAndrii Nakryiko 3481d5caef5bSAndrii Nakryiko while (is_type_mapped(d, type_id) && d->map[type_id] != type_id) 3482d5caef5bSAndrii Nakryiko type_id = d->map[type_id]; 3483d5caef5bSAndrii Nakryiko 3484740e69c3SAndrii Nakryiko if (!btf_is_fwd(btf__type_by_id(d->btf, type_id))) 3485d5caef5bSAndrii Nakryiko return type_id; 3486d5caef5bSAndrii Nakryiko 3487d5caef5bSAndrii Nakryiko return orig_type_id; 3488d5caef5bSAndrii Nakryiko } 3489d5caef5bSAndrii Nakryiko 3490d5caef5bSAndrii Nakryiko 3491d5caef5bSAndrii Nakryiko static inline __u16 btf_fwd_kind(struct btf_type *t) 3492d5caef5bSAndrii Nakryiko { 3493b03bc685SAndrii Nakryiko return btf_kflag(t) ? BTF_KIND_UNION : BTF_KIND_STRUCT; 3494d5caef5bSAndrii Nakryiko } 3495d5caef5bSAndrii Nakryiko 3496d5caef5bSAndrii Nakryiko /* 3497d5caef5bSAndrii Nakryiko * Check equivalence of BTF type graph formed by candidate struct/union (we'll 3498d5caef5bSAndrii Nakryiko * call it "candidate graph" in this description for brevity) to a type graph 3499d5caef5bSAndrii Nakryiko * formed by (potential) canonical struct/union ("canonical graph" for brevity 3500d5caef5bSAndrii Nakryiko * here, though keep in mind that not all types in canonical graph are 3501d5caef5bSAndrii Nakryiko * necessarily canonical representatives themselves, some of them might be 3502d5caef5bSAndrii Nakryiko * duplicates or its uniqueness might not have been established yet). 3503d5caef5bSAndrii Nakryiko * Returns: 3504d5caef5bSAndrii Nakryiko * - >0, if type graphs are equivalent; 3505d5caef5bSAndrii Nakryiko * - 0, if not equivalent; 3506d5caef5bSAndrii Nakryiko * - <0, on error. 3507d5caef5bSAndrii Nakryiko * 3508d5caef5bSAndrii Nakryiko * Algorithm performs side-by-side DFS traversal of both type graphs and checks 3509d5caef5bSAndrii Nakryiko * equivalence of BTF types at each step. If at any point BTF types in candidate 3510d5caef5bSAndrii Nakryiko * and canonical graphs are not compatible structurally, whole graphs are 3511d5caef5bSAndrii Nakryiko * incompatible. If types are structurally equivalent (i.e., all information 3512d5caef5bSAndrii Nakryiko * except referenced type IDs is exactly the same), a mapping from `canon_id` to 3513d5caef5bSAndrii Nakryiko * a `cand_id` is recored in hypothetical mapping (`btf_dedup->hypot_map`). 3514d5caef5bSAndrii Nakryiko * If a type references other types, then those referenced types are checked 3515d5caef5bSAndrii Nakryiko * for equivalence recursively. 3516d5caef5bSAndrii Nakryiko * 3517d5caef5bSAndrii Nakryiko * During DFS traversal, if we find that for current `canon_id` type we 3518d5caef5bSAndrii Nakryiko * already have some mapping in hypothetical map, we check for two possible 3519d5caef5bSAndrii Nakryiko * situations: 3520d5caef5bSAndrii Nakryiko * - `canon_id` is mapped to exactly the same type as `cand_id`. This will 3521d5caef5bSAndrii Nakryiko * happen when type graphs have cycles. In this case we assume those two 3522d5caef5bSAndrii Nakryiko * types are equivalent. 3523d5caef5bSAndrii Nakryiko * - `canon_id` is mapped to different type. This is contradiction in our 3524d5caef5bSAndrii Nakryiko * hypothetical mapping, because same graph in canonical graph corresponds 3525d5caef5bSAndrii Nakryiko * to two different types in candidate graph, which for equivalent type 3526d5caef5bSAndrii Nakryiko * graphs shouldn't happen. This condition terminates equivalence check 3527d5caef5bSAndrii Nakryiko * with negative result. 3528d5caef5bSAndrii Nakryiko * 3529d5caef5bSAndrii Nakryiko * If type graphs traversal exhausts types to check and find no contradiction, 3530d5caef5bSAndrii Nakryiko * then type graphs are equivalent. 3531d5caef5bSAndrii Nakryiko * 3532d5caef5bSAndrii Nakryiko * When checking types for equivalence, there is one special case: FWD types. 3533d5caef5bSAndrii Nakryiko * If FWD type resolution is allowed and one of the types (either from canonical 3534d5caef5bSAndrii Nakryiko * or candidate graph) is FWD and other is STRUCT/UNION (depending on FWD's kind 3535d5caef5bSAndrii Nakryiko * flag) and their names match, hypothetical mapping is updated to point from 3536d5caef5bSAndrii Nakryiko * FWD to STRUCT/UNION. If graphs will be determined as equivalent successfully, 3537d5caef5bSAndrii Nakryiko * this mapping will be used to record FWD -> STRUCT/UNION mapping permanently. 3538d5caef5bSAndrii Nakryiko * 3539d5caef5bSAndrii Nakryiko * Technically, this could lead to incorrect FWD to STRUCT/UNION resolution, 3540d5caef5bSAndrii Nakryiko * if there are two exactly named (or anonymous) structs/unions that are 3541d5caef5bSAndrii Nakryiko * compatible structurally, one of which has FWD field, while other is concrete 3542d5caef5bSAndrii Nakryiko * STRUCT/UNION, but according to C sources they are different structs/unions 3543d5caef5bSAndrii Nakryiko * that are referencing different types with the same name. This is extremely 3544d5caef5bSAndrii Nakryiko * unlikely to happen, but btf_dedup API allows to disable FWD resolution if 3545d5caef5bSAndrii Nakryiko * this logic is causing problems. 3546d5caef5bSAndrii Nakryiko * 3547d5caef5bSAndrii Nakryiko * Doing FWD resolution means that both candidate and/or canonical graphs can 3548d5caef5bSAndrii Nakryiko * consists of portions of the graph that come from multiple compilation units. 3549d5caef5bSAndrii Nakryiko * This is due to the fact that types within single compilation unit are always 3550d5caef5bSAndrii Nakryiko * deduplicated and FWDs are already resolved, if referenced struct/union 3551d5caef5bSAndrii Nakryiko * definiton is available. So, if we had unresolved FWD and found corresponding 3552d5caef5bSAndrii Nakryiko * STRUCT/UNION, they will be from different compilation units. This 3553d5caef5bSAndrii Nakryiko * consequently means that when we "link" FWD to corresponding STRUCT/UNION, 3554d5caef5bSAndrii Nakryiko * type graph will likely have at least two different BTF types that describe 3555d5caef5bSAndrii Nakryiko * same type (e.g., most probably there will be two different BTF types for the 3556d5caef5bSAndrii Nakryiko * same 'int' primitive type) and could even have "overlapping" parts of type 3557d5caef5bSAndrii Nakryiko * graph that describe same subset of types. 3558d5caef5bSAndrii Nakryiko * 3559d5caef5bSAndrii Nakryiko * This in turn means that our assumption that each type in canonical graph 3560d5caef5bSAndrii Nakryiko * must correspond to exactly one type in candidate graph might not hold 3561d5caef5bSAndrii Nakryiko * anymore and will make it harder to detect contradictions using hypothetical 3562d5caef5bSAndrii Nakryiko * map. To handle this problem, we allow to follow FWD -> STRUCT/UNION 3563d5caef5bSAndrii Nakryiko * resolution only in canonical graph. FWDs in candidate graphs are never 3564d5caef5bSAndrii Nakryiko * resolved. To see why it's OK, let's check all possible situations w.r.t. FWDs 3565d5caef5bSAndrii Nakryiko * that can occur: 3566d5caef5bSAndrii Nakryiko * - Both types in canonical and candidate graphs are FWDs. If they are 3567d5caef5bSAndrii Nakryiko * structurally equivalent, then they can either be both resolved to the 3568d5caef5bSAndrii Nakryiko * same STRUCT/UNION or not resolved at all. In both cases they are 3569d5caef5bSAndrii Nakryiko * equivalent and there is no need to resolve FWD on candidate side. 3570d5caef5bSAndrii Nakryiko * - Both types in canonical and candidate graphs are concrete STRUCT/UNION, 3571d5caef5bSAndrii Nakryiko * so nothing to resolve as well, algorithm will check equivalence anyway. 3572d5caef5bSAndrii Nakryiko * - Type in canonical graph is FWD, while type in candidate is concrete 3573d5caef5bSAndrii Nakryiko * STRUCT/UNION. In this case candidate graph comes from single compilation 3574d5caef5bSAndrii Nakryiko * unit, so there is exactly one BTF type for each unique C type. After 3575d5caef5bSAndrii Nakryiko * resolving FWD into STRUCT/UNION, there might be more than one BTF type 3576d5caef5bSAndrii Nakryiko * in canonical graph mapping to single BTF type in candidate graph, but 3577d5caef5bSAndrii Nakryiko * because hypothetical mapping maps from canonical to candidate types, it's 3578d5caef5bSAndrii Nakryiko * alright, and we still maintain the property of having single `canon_id` 3579d5caef5bSAndrii Nakryiko * mapping to single `cand_id` (there could be two different `canon_id` 3580d5caef5bSAndrii Nakryiko * mapped to the same `cand_id`, but it's not contradictory). 3581d5caef5bSAndrii Nakryiko * - Type in canonical graph is concrete STRUCT/UNION, while type in candidate 3582d5caef5bSAndrii Nakryiko * graph is FWD. In this case we are just going to check compatibility of 3583d5caef5bSAndrii Nakryiko * STRUCT/UNION and corresponding FWD, and if they are compatible, we'll 3584d5caef5bSAndrii Nakryiko * assume that whatever STRUCT/UNION FWD resolves to must be equivalent to 3585d5caef5bSAndrii Nakryiko * a concrete STRUCT/UNION from canonical graph. If the rest of type graphs 3586d5caef5bSAndrii Nakryiko * turn out equivalent, we'll re-resolve FWD to concrete STRUCT/UNION from 3587d5caef5bSAndrii Nakryiko * canonical graph. 3588d5caef5bSAndrii Nakryiko */ 3589d5caef5bSAndrii Nakryiko static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id, 3590d5caef5bSAndrii Nakryiko __u32 canon_id) 3591d5caef5bSAndrii Nakryiko { 3592d5caef5bSAndrii Nakryiko struct btf_type *cand_type; 3593d5caef5bSAndrii Nakryiko struct btf_type *canon_type; 3594d5caef5bSAndrii Nakryiko __u32 hypot_type_id; 3595d5caef5bSAndrii Nakryiko __u16 cand_kind; 3596d5caef5bSAndrii Nakryiko __u16 canon_kind; 3597d5caef5bSAndrii Nakryiko int i, eq; 3598d5caef5bSAndrii Nakryiko 3599d5caef5bSAndrii Nakryiko /* if both resolve to the same canonical, they must be equivalent */ 3600d5caef5bSAndrii Nakryiko if (resolve_type_id(d, cand_id) == resolve_type_id(d, canon_id)) 3601d5caef5bSAndrii Nakryiko return 1; 3602d5caef5bSAndrii Nakryiko 3603d5caef5bSAndrii Nakryiko canon_id = resolve_fwd_id(d, canon_id); 3604d5caef5bSAndrii Nakryiko 3605d5caef5bSAndrii Nakryiko hypot_type_id = d->hypot_map[canon_id]; 36065aab392cSAndrii Nakryiko if (hypot_type_id <= BTF_MAX_NR_TYPES) 3607d5caef5bSAndrii Nakryiko return hypot_type_id == cand_id; 3608d5caef5bSAndrii Nakryiko 3609d5caef5bSAndrii Nakryiko if (btf_dedup_hypot_map_add(d, canon_id, cand_id)) 3610d5caef5bSAndrii Nakryiko return -ENOMEM; 3611d5caef5bSAndrii Nakryiko 3612740e69c3SAndrii Nakryiko cand_type = btf_type_by_id(d->btf, cand_id); 3613740e69c3SAndrii Nakryiko canon_type = btf_type_by_id(d->btf, canon_id); 3614b03bc685SAndrii Nakryiko cand_kind = btf_kind(cand_type); 3615b03bc685SAndrii Nakryiko canon_kind = btf_kind(canon_type); 3616d5caef5bSAndrii Nakryiko 3617d5caef5bSAndrii Nakryiko if (cand_type->name_off != canon_type->name_off) 3618d5caef5bSAndrii Nakryiko return 0; 3619d5caef5bSAndrii Nakryiko 3620d5caef5bSAndrii Nakryiko /* FWD <--> STRUCT/UNION equivalence check, if enabled */ 3621d5caef5bSAndrii Nakryiko if (!d->opts.dont_resolve_fwds 3622d5caef5bSAndrii Nakryiko && (cand_kind == BTF_KIND_FWD || canon_kind == BTF_KIND_FWD) 3623d5caef5bSAndrii Nakryiko && cand_kind != canon_kind) { 3624d5caef5bSAndrii Nakryiko __u16 real_kind; 3625d5caef5bSAndrii Nakryiko __u16 fwd_kind; 3626d5caef5bSAndrii Nakryiko 3627d5caef5bSAndrii Nakryiko if (cand_kind == BTF_KIND_FWD) { 3628d5caef5bSAndrii Nakryiko real_kind = canon_kind; 3629d5caef5bSAndrii Nakryiko fwd_kind = btf_fwd_kind(cand_type); 3630d5caef5bSAndrii Nakryiko } else { 3631d5caef5bSAndrii Nakryiko real_kind = cand_kind; 3632d5caef5bSAndrii Nakryiko fwd_kind = btf_fwd_kind(canon_type); 3633d5caef5bSAndrii Nakryiko } 3634d5caef5bSAndrii Nakryiko return fwd_kind == real_kind; 3635d5caef5bSAndrii Nakryiko } 3636d5caef5bSAndrii Nakryiko 36379ec71c1cSAndrii Nakryiko if (cand_kind != canon_kind) 36389ec71c1cSAndrii Nakryiko return 0; 36399ec71c1cSAndrii Nakryiko 3640d5caef5bSAndrii Nakryiko switch (cand_kind) { 3641d5caef5bSAndrii Nakryiko case BTF_KIND_INT: 3642d5caef5bSAndrii Nakryiko return btf_equal_int(cand_type, canon_type); 3643d5caef5bSAndrii Nakryiko 3644d5caef5bSAndrii Nakryiko case BTF_KIND_ENUM: 36459768095bSAndrii Nakryiko if (d->opts.dont_resolve_fwds) 3646d5caef5bSAndrii Nakryiko return btf_equal_enum(cand_type, canon_type); 36479768095bSAndrii Nakryiko else 36489768095bSAndrii Nakryiko return btf_compat_enum(cand_type, canon_type); 3649d5caef5bSAndrii Nakryiko 3650d5caef5bSAndrii Nakryiko case BTF_KIND_FWD: 3651d5caef5bSAndrii Nakryiko return btf_equal_common(cand_type, canon_type); 3652d5caef5bSAndrii Nakryiko 3653d5caef5bSAndrii Nakryiko case BTF_KIND_CONST: 3654d5caef5bSAndrii Nakryiko case BTF_KIND_VOLATILE: 3655d5caef5bSAndrii Nakryiko case BTF_KIND_RESTRICT: 3656d5caef5bSAndrii Nakryiko case BTF_KIND_PTR: 3657d5caef5bSAndrii Nakryiko case BTF_KIND_TYPEDEF: 3658d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC: 36599768095bSAndrii Nakryiko if (cand_type->info != canon_type->info) 36609768095bSAndrii Nakryiko return 0; 3661d5caef5bSAndrii Nakryiko return btf_dedup_is_equiv(d, cand_type->type, canon_type->type); 3662d5caef5bSAndrii Nakryiko 3663d5caef5bSAndrii Nakryiko case BTF_KIND_ARRAY: { 3664b03bc685SAndrii Nakryiko const struct btf_array *cand_arr, *canon_arr; 3665d5caef5bSAndrii Nakryiko 3666d5caef5bSAndrii Nakryiko if (!btf_compat_array(cand_type, canon_type)) 3667d5caef5bSAndrii Nakryiko return 0; 3668b03bc685SAndrii Nakryiko cand_arr = btf_array(cand_type); 3669b03bc685SAndrii Nakryiko canon_arr = btf_array(canon_type); 3670d5caef5bSAndrii Nakryiko eq = btf_dedup_is_equiv(d, 3671d5caef5bSAndrii Nakryiko cand_arr->index_type, canon_arr->index_type); 3672d5caef5bSAndrii Nakryiko if (eq <= 0) 3673d5caef5bSAndrii Nakryiko return eq; 3674d5caef5bSAndrii Nakryiko return btf_dedup_is_equiv(d, cand_arr->type, canon_arr->type); 3675d5caef5bSAndrii Nakryiko } 3676d5caef5bSAndrii Nakryiko 3677d5caef5bSAndrii Nakryiko case BTF_KIND_STRUCT: 3678d5caef5bSAndrii Nakryiko case BTF_KIND_UNION: { 3679b03bc685SAndrii Nakryiko const struct btf_member *cand_m, *canon_m; 3680d5caef5bSAndrii Nakryiko __u16 vlen; 3681d5caef5bSAndrii Nakryiko 368291097fbeSAndrii Nakryiko if (!btf_shallow_equal_struct(cand_type, canon_type)) 3683d5caef5bSAndrii Nakryiko return 0; 3684b03bc685SAndrii Nakryiko vlen = btf_vlen(cand_type); 3685b03bc685SAndrii Nakryiko cand_m = btf_members(cand_type); 3686b03bc685SAndrii Nakryiko canon_m = btf_members(canon_type); 3687d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3688d5caef5bSAndrii Nakryiko eq = btf_dedup_is_equiv(d, cand_m->type, canon_m->type); 3689d5caef5bSAndrii Nakryiko if (eq <= 0) 3690d5caef5bSAndrii Nakryiko return eq; 3691d5caef5bSAndrii Nakryiko cand_m++; 3692d5caef5bSAndrii Nakryiko canon_m++; 3693d5caef5bSAndrii Nakryiko } 3694d5caef5bSAndrii Nakryiko 3695d5caef5bSAndrii Nakryiko return 1; 3696d5caef5bSAndrii Nakryiko } 3697d5caef5bSAndrii Nakryiko 3698d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC_PROTO: { 3699b03bc685SAndrii Nakryiko const struct btf_param *cand_p, *canon_p; 3700d5caef5bSAndrii Nakryiko __u16 vlen; 3701d5caef5bSAndrii Nakryiko 3702d5caef5bSAndrii Nakryiko if (!btf_compat_fnproto(cand_type, canon_type)) 3703d5caef5bSAndrii Nakryiko return 0; 3704d5caef5bSAndrii Nakryiko eq = btf_dedup_is_equiv(d, cand_type->type, canon_type->type); 3705d5caef5bSAndrii Nakryiko if (eq <= 0) 3706d5caef5bSAndrii Nakryiko return eq; 3707b03bc685SAndrii Nakryiko vlen = btf_vlen(cand_type); 3708b03bc685SAndrii Nakryiko cand_p = btf_params(cand_type); 3709b03bc685SAndrii Nakryiko canon_p = btf_params(canon_type); 3710d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3711d5caef5bSAndrii Nakryiko eq = btf_dedup_is_equiv(d, cand_p->type, canon_p->type); 3712d5caef5bSAndrii Nakryiko if (eq <= 0) 3713d5caef5bSAndrii Nakryiko return eq; 3714d5caef5bSAndrii Nakryiko cand_p++; 3715d5caef5bSAndrii Nakryiko canon_p++; 3716d5caef5bSAndrii Nakryiko } 3717d5caef5bSAndrii Nakryiko return 1; 3718d5caef5bSAndrii Nakryiko } 3719d5caef5bSAndrii Nakryiko 3720d5caef5bSAndrii Nakryiko default: 3721d5caef5bSAndrii Nakryiko return -EINVAL; 3722d5caef5bSAndrii Nakryiko } 3723d5caef5bSAndrii Nakryiko return 0; 3724d5caef5bSAndrii Nakryiko } 3725d5caef5bSAndrii Nakryiko 3726d5caef5bSAndrii Nakryiko /* 3727d5caef5bSAndrii Nakryiko * Use hypothetical mapping, produced by successful type graph equivalence 3728d5caef5bSAndrii Nakryiko * check, to augment existing struct/union canonical mapping, where possible. 3729d5caef5bSAndrii Nakryiko * 3730d5caef5bSAndrii Nakryiko * If BTF_KIND_FWD resolution is allowed, this mapping is also used to record 3731d5caef5bSAndrii Nakryiko * FWD -> STRUCT/UNION correspondence as well. FWD resolution is bidirectional: 3732d5caef5bSAndrii Nakryiko * it doesn't matter if FWD type was part of canonical graph or candidate one, 3733d5caef5bSAndrii Nakryiko * we are recording the mapping anyway. As opposed to carefulness required 3734d5caef5bSAndrii Nakryiko * for struct/union correspondence mapping (described below), for FWD resolution 3735d5caef5bSAndrii Nakryiko * it's not important, as by the time that FWD type (reference type) will be 3736d5caef5bSAndrii Nakryiko * deduplicated all structs/unions will be deduped already anyway. 3737d5caef5bSAndrii Nakryiko * 3738d5caef5bSAndrii Nakryiko * Recording STRUCT/UNION mapping is purely a performance optimization and is 3739d5caef5bSAndrii Nakryiko * not required for correctness. It needs to be done carefully to ensure that 3740d5caef5bSAndrii Nakryiko * struct/union from candidate's type graph is not mapped into corresponding 3741d5caef5bSAndrii Nakryiko * struct/union from canonical type graph that itself hasn't been resolved into 3742d5caef5bSAndrii Nakryiko * canonical representative. The only guarantee we have is that canonical 3743d5caef5bSAndrii Nakryiko * struct/union was determined as canonical and that won't change. But any 3744d5caef5bSAndrii Nakryiko * types referenced through that struct/union fields could have been not yet 3745d5caef5bSAndrii Nakryiko * resolved, so in case like that it's too early to establish any kind of 3746d5caef5bSAndrii Nakryiko * correspondence between structs/unions. 3747d5caef5bSAndrii Nakryiko * 3748d5caef5bSAndrii Nakryiko * No canonical correspondence is derived for primitive types (they are already 3749d5caef5bSAndrii Nakryiko * deduplicated completely already anyway) or reference types (they rely on 3750d5caef5bSAndrii Nakryiko * stability of struct/union canonical relationship for equivalence checks). 3751d5caef5bSAndrii Nakryiko */ 3752d5caef5bSAndrii Nakryiko static void btf_dedup_merge_hypot_map(struct btf_dedup *d) 3753d5caef5bSAndrii Nakryiko { 3754d5caef5bSAndrii Nakryiko __u32 cand_type_id, targ_type_id; 3755d5caef5bSAndrii Nakryiko __u16 t_kind, c_kind; 3756d5caef5bSAndrii Nakryiko __u32 t_id, c_id; 3757d5caef5bSAndrii Nakryiko int i; 3758d5caef5bSAndrii Nakryiko 3759d5caef5bSAndrii Nakryiko for (i = 0; i < d->hypot_cnt; i++) { 3760d5caef5bSAndrii Nakryiko cand_type_id = d->hypot_list[i]; 3761d5caef5bSAndrii Nakryiko targ_type_id = d->hypot_map[cand_type_id]; 3762d5caef5bSAndrii Nakryiko t_id = resolve_type_id(d, targ_type_id); 3763d5caef5bSAndrii Nakryiko c_id = resolve_type_id(d, cand_type_id); 3764740e69c3SAndrii Nakryiko t_kind = btf_kind(btf__type_by_id(d->btf, t_id)); 3765740e69c3SAndrii Nakryiko c_kind = btf_kind(btf__type_by_id(d->btf, c_id)); 3766d5caef5bSAndrii Nakryiko /* 3767d5caef5bSAndrii Nakryiko * Resolve FWD into STRUCT/UNION. 3768d5caef5bSAndrii Nakryiko * It's ok to resolve FWD into STRUCT/UNION that's not yet 3769d5caef5bSAndrii Nakryiko * mapped to canonical representative (as opposed to 3770d5caef5bSAndrii Nakryiko * STRUCT/UNION <--> STRUCT/UNION mapping logic below), because 3771d5caef5bSAndrii Nakryiko * eventually that struct is going to be mapped and all resolved 3772d5caef5bSAndrii Nakryiko * FWDs will automatically resolve to correct canonical 3773d5caef5bSAndrii Nakryiko * representative. This will happen before ref type deduping, 3774d5caef5bSAndrii Nakryiko * which critically depends on stability of these mapping. This 3775d5caef5bSAndrii Nakryiko * stability is not a requirement for STRUCT/UNION equivalence 3776d5caef5bSAndrii Nakryiko * checks, though. 3777d5caef5bSAndrii Nakryiko */ 3778d5caef5bSAndrii Nakryiko if (t_kind != BTF_KIND_FWD && c_kind == BTF_KIND_FWD) 3779d5caef5bSAndrii Nakryiko d->map[c_id] = t_id; 3780d5caef5bSAndrii Nakryiko else if (t_kind == BTF_KIND_FWD && c_kind != BTF_KIND_FWD) 3781d5caef5bSAndrii Nakryiko d->map[t_id] = c_id; 3782d5caef5bSAndrii Nakryiko 3783d5caef5bSAndrii Nakryiko if ((t_kind == BTF_KIND_STRUCT || t_kind == BTF_KIND_UNION) && 3784d5caef5bSAndrii Nakryiko c_kind != BTF_KIND_FWD && 3785d5caef5bSAndrii Nakryiko is_type_mapped(d, c_id) && 3786d5caef5bSAndrii Nakryiko !is_type_mapped(d, t_id)) { 3787d5caef5bSAndrii Nakryiko /* 3788d5caef5bSAndrii Nakryiko * as a perf optimization, we can map struct/union 3789d5caef5bSAndrii Nakryiko * that's part of type graph we just verified for 3790d5caef5bSAndrii Nakryiko * equivalence. We can do that for struct/union that has 3791d5caef5bSAndrii Nakryiko * canonical representative only, though. 3792d5caef5bSAndrii Nakryiko */ 3793d5caef5bSAndrii Nakryiko d->map[t_id] = c_id; 3794d5caef5bSAndrii Nakryiko } 3795d5caef5bSAndrii Nakryiko } 3796d5caef5bSAndrii Nakryiko } 3797d5caef5bSAndrii Nakryiko 3798d5caef5bSAndrii Nakryiko /* 3799d5caef5bSAndrii Nakryiko * Deduplicate struct/union types. 3800d5caef5bSAndrii Nakryiko * 3801d5caef5bSAndrii Nakryiko * For each struct/union type its type signature hash is calculated, taking 3802d5caef5bSAndrii Nakryiko * into account type's name, size, number, order and names of fields, but 3803d5caef5bSAndrii Nakryiko * ignoring type ID's referenced from fields, because they might not be deduped 3804d5caef5bSAndrii Nakryiko * completely until after reference types deduplication phase. This type hash 3805d5caef5bSAndrii Nakryiko * is used to iterate over all potential canonical types, sharing same hash. 3806d5caef5bSAndrii Nakryiko * For each canonical candidate we check whether type graphs that they form 3807d5caef5bSAndrii Nakryiko * (through referenced types in fields and so on) are equivalent using algorithm 3808d5caef5bSAndrii Nakryiko * implemented in `btf_dedup_is_equiv`. If such equivalence is found and 3809d5caef5bSAndrii Nakryiko * BTF_KIND_FWD resolution is allowed, then hypothetical mapping 3810d5caef5bSAndrii Nakryiko * (btf_dedup->hypot_map) produced by aforementioned type graph equivalence 3811d5caef5bSAndrii Nakryiko * algorithm is used to record FWD -> STRUCT/UNION mapping. It's also used to 3812d5caef5bSAndrii Nakryiko * potentially map other structs/unions to their canonical representatives, 3813d5caef5bSAndrii Nakryiko * if such relationship hasn't yet been established. This speeds up algorithm 3814d5caef5bSAndrii Nakryiko * by eliminating some of the duplicate work. 3815d5caef5bSAndrii Nakryiko * 3816d5caef5bSAndrii Nakryiko * If no matching canonical representative was found, struct/union is marked 3817d5caef5bSAndrii Nakryiko * as canonical for itself and is added into btf_dedup->dedup_table hash map 3818d5caef5bSAndrii Nakryiko * for further look ups. 3819d5caef5bSAndrii Nakryiko */ 3820d5caef5bSAndrii Nakryiko static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id) 3821d5caef5bSAndrii Nakryiko { 382291097fbeSAndrii Nakryiko struct btf_type *cand_type, *t; 38232fc3fc0bSAndrii Nakryiko struct hashmap_entry *hash_entry; 3824d5caef5bSAndrii Nakryiko /* if we don't find equivalent type, then we are canonical */ 3825d5caef5bSAndrii Nakryiko __u32 new_id = type_id; 3826d5caef5bSAndrii Nakryiko __u16 kind; 38272fc3fc0bSAndrii Nakryiko long h; 3828d5caef5bSAndrii Nakryiko 3829d5caef5bSAndrii Nakryiko /* already deduped or is in process of deduping (loop detected) */ 38305aab392cSAndrii Nakryiko if (d->map[type_id] <= BTF_MAX_NR_TYPES) 3831d5caef5bSAndrii Nakryiko return 0; 3832d5caef5bSAndrii Nakryiko 3833740e69c3SAndrii Nakryiko t = btf_type_by_id(d->btf, type_id); 3834b03bc685SAndrii Nakryiko kind = btf_kind(t); 3835d5caef5bSAndrii Nakryiko 3836d5caef5bSAndrii Nakryiko if (kind != BTF_KIND_STRUCT && kind != BTF_KIND_UNION) 3837d5caef5bSAndrii Nakryiko return 0; 3838d5caef5bSAndrii Nakryiko 3839d5caef5bSAndrii Nakryiko h = btf_hash_struct(t); 38402fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 38412fc3fc0bSAndrii Nakryiko __u32 cand_id = (__u32)(long)hash_entry->value; 3842d5caef5bSAndrii Nakryiko int eq; 3843d5caef5bSAndrii Nakryiko 384491097fbeSAndrii Nakryiko /* 384591097fbeSAndrii Nakryiko * Even though btf_dedup_is_equiv() checks for 384691097fbeSAndrii Nakryiko * btf_shallow_equal_struct() internally when checking two 384791097fbeSAndrii Nakryiko * structs (unions) for equivalence, we need to guard here 384891097fbeSAndrii Nakryiko * from picking matching FWD type as a dedup candidate. 384991097fbeSAndrii Nakryiko * This can happen due to hash collision. In such case just 385091097fbeSAndrii Nakryiko * relying on btf_dedup_is_equiv() would lead to potentially 385191097fbeSAndrii Nakryiko * creating a loop (FWD -> STRUCT and STRUCT -> FWD), because 385291097fbeSAndrii Nakryiko * FWD and compatible STRUCT/UNION are considered equivalent. 385391097fbeSAndrii Nakryiko */ 3854740e69c3SAndrii Nakryiko cand_type = btf_type_by_id(d->btf, cand_id); 385591097fbeSAndrii Nakryiko if (!btf_shallow_equal_struct(t, cand_type)) 385691097fbeSAndrii Nakryiko continue; 385791097fbeSAndrii Nakryiko 3858d5caef5bSAndrii Nakryiko btf_dedup_clear_hypot_map(d); 38592fc3fc0bSAndrii Nakryiko eq = btf_dedup_is_equiv(d, type_id, cand_id); 3860d5caef5bSAndrii Nakryiko if (eq < 0) 3861d5caef5bSAndrii Nakryiko return eq; 3862d5caef5bSAndrii Nakryiko if (!eq) 3863d5caef5bSAndrii Nakryiko continue; 38642fc3fc0bSAndrii Nakryiko new_id = cand_id; 3865d5caef5bSAndrii Nakryiko btf_dedup_merge_hypot_map(d); 3866d5caef5bSAndrii Nakryiko break; 3867d5caef5bSAndrii Nakryiko } 3868d5caef5bSAndrii Nakryiko 3869d5caef5bSAndrii Nakryiko d->map[type_id] = new_id; 3870d5caef5bSAndrii Nakryiko if (type_id == new_id && btf_dedup_table_add(d, h, type_id)) 3871d5caef5bSAndrii Nakryiko return -ENOMEM; 3872d5caef5bSAndrii Nakryiko 3873d5caef5bSAndrii Nakryiko return 0; 3874d5caef5bSAndrii Nakryiko } 3875d5caef5bSAndrii Nakryiko 3876d5caef5bSAndrii Nakryiko static int btf_dedup_struct_types(struct btf_dedup *d) 3877d5caef5bSAndrii Nakryiko { 3878d5caef5bSAndrii Nakryiko int i, err; 3879d5caef5bSAndrii Nakryiko 3880d5caef5bSAndrii Nakryiko for (i = 1; i <= d->btf->nr_types; i++) { 3881d5caef5bSAndrii Nakryiko err = btf_dedup_struct_type(d, i); 3882d5caef5bSAndrii Nakryiko if (err) 3883d5caef5bSAndrii Nakryiko return err; 3884d5caef5bSAndrii Nakryiko } 3885d5caef5bSAndrii Nakryiko return 0; 3886d5caef5bSAndrii Nakryiko } 3887d5caef5bSAndrii Nakryiko 3888d5caef5bSAndrii Nakryiko /* 3889d5caef5bSAndrii Nakryiko * Deduplicate reference type. 3890d5caef5bSAndrii Nakryiko * 3891d5caef5bSAndrii Nakryiko * Once all primitive and struct/union types got deduplicated, we can easily 3892d5caef5bSAndrii Nakryiko * deduplicate all other (reference) BTF types. This is done in two steps: 3893d5caef5bSAndrii Nakryiko * 3894d5caef5bSAndrii Nakryiko * 1. Resolve all referenced type IDs into their canonical type IDs. This 3895d5caef5bSAndrii Nakryiko * resolution can be done either immediately for primitive or struct/union types 3896d5caef5bSAndrii Nakryiko * (because they were deduped in previous two phases) or recursively for 3897d5caef5bSAndrii Nakryiko * reference types. Recursion will always terminate at either primitive or 3898d5caef5bSAndrii Nakryiko * struct/union type, at which point we can "unwind" chain of reference types 3899d5caef5bSAndrii Nakryiko * one by one. There is no danger of encountering cycles because in C type 3900d5caef5bSAndrii Nakryiko * system the only way to form type cycle is through struct/union, so any chain 3901d5caef5bSAndrii Nakryiko * of reference types, even those taking part in a type cycle, will inevitably 3902d5caef5bSAndrii Nakryiko * reach struct/union at some point. 3903d5caef5bSAndrii Nakryiko * 3904d5caef5bSAndrii Nakryiko * 2. Once all referenced type IDs are resolved into canonical ones, BTF type 3905d5caef5bSAndrii Nakryiko * becomes "stable", in the sense that no further deduplication will cause 3906d5caef5bSAndrii Nakryiko * any changes to it. With that, it's now possible to calculate type's signature 3907d5caef5bSAndrii Nakryiko * hash (this time taking into account referenced type IDs) and loop over all 3908d5caef5bSAndrii Nakryiko * potential canonical representatives. If no match was found, current type 3909d5caef5bSAndrii Nakryiko * will become canonical representative of itself and will be added into 3910d5caef5bSAndrii Nakryiko * btf_dedup->dedup_table as another possible canonical representative. 3911d5caef5bSAndrii Nakryiko */ 3912d5caef5bSAndrii Nakryiko static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id) 3913d5caef5bSAndrii Nakryiko { 39142fc3fc0bSAndrii Nakryiko struct hashmap_entry *hash_entry; 39152fc3fc0bSAndrii Nakryiko __u32 new_id = type_id, cand_id; 3916d5caef5bSAndrii Nakryiko struct btf_type *t, *cand; 3917d5caef5bSAndrii Nakryiko /* if we don't find equivalent type, then we are representative type */ 39183d8669e6SDan Carpenter int ref_type_id; 39192fc3fc0bSAndrii Nakryiko long h; 3920d5caef5bSAndrii Nakryiko 3921d5caef5bSAndrii Nakryiko if (d->map[type_id] == BTF_IN_PROGRESS_ID) 3922d5caef5bSAndrii Nakryiko return -ELOOP; 39235aab392cSAndrii Nakryiko if (d->map[type_id] <= BTF_MAX_NR_TYPES) 3924d5caef5bSAndrii Nakryiko return resolve_type_id(d, type_id); 3925d5caef5bSAndrii Nakryiko 3926740e69c3SAndrii Nakryiko t = btf_type_by_id(d->btf, type_id); 3927d5caef5bSAndrii Nakryiko d->map[type_id] = BTF_IN_PROGRESS_ID; 3928d5caef5bSAndrii Nakryiko 3929b03bc685SAndrii Nakryiko switch (btf_kind(t)) { 3930d5caef5bSAndrii Nakryiko case BTF_KIND_CONST: 3931d5caef5bSAndrii Nakryiko case BTF_KIND_VOLATILE: 3932d5caef5bSAndrii Nakryiko case BTF_KIND_RESTRICT: 3933d5caef5bSAndrii Nakryiko case BTF_KIND_PTR: 3934d5caef5bSAndrii Nakryiko case BTF_KIND_TYPEDEF: 3935d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC: 3936d5caef5bSAndrii Nakryiko ref_type_id = btf_dedup_ref_type(d, t->type); 3937d5caef5bSAndrii Nakryiko if (ref_type_id < 0) 3938d5caef5bSAndrii Nakryiko return ref_type_id; 3939d5caef5bSAndrii Nakryiko t->type = ref_type_id; 3940d5caef5bSAndrii Nakryiko 3941d5caef5bSAndrii Nakryiko h = btf_hash_common(t); 39422fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 39432fc3fc0bSAndrii Nakryiko cand_id = (__u32)(long)hash_entry->value; 3944740e69c3SAndrii Nakryiko cand = btf_type_by_id(d->btf, cand_id); 3945d5caef5bSAndrii Nakryiko if (btf_equal_common(t, cand)) { 39462fc3fc0bSAndrii Nakryiko new_id = cand_id; 3947d5caef5bSAndrii Nakryiko break; 3948d5caef5bSAndrii Nakryiko } 3949d5caef5bSAndrii Nakryiko } 3950d5caef5bSAndrii Nakryiko break; 3951d5caef5bSAndrii Nakryiko 3952d5caef5bSAndrii Nakryiko case BTF_KIND_ARRAY: { 3953b03bc685SAndrii Nakryiko struct btf_array *info = btf_array(t); 3954d5caef5bSAndrii Nakryiko 3955d5caef5bSAndrii Nakryiko ref_type_id = btf_dedup_ref_type(d, info->type); 3956d5caef5bSAndrii Nakryiko if (ref_type_id < 0) 3957d5caef5bSAndrii Nakryiko return ref_type_id; 3958d5caef5bSAndrii Nakryiko info->type = ref_type_id; 3959d5caef5bSAndrii Nakryiko 3960d5caef5bSAndrii Nakryiko ref_type_id = btf_dedup_ref_type(d, info->index_type); 3961d5caef5bSAndrii Nakryiko if (ref_type_id < 0) 3962d5caef5bSAndrii Nakryiko return ref_type_id; 3963d5caef5bSAndrii Nakryiko info->index_type = ref_type_id; 3964d5caef5bSAndrii Nakryiko 3965d5caef5bSAndrii Nakryiko h = btf_hash_array(t); 39662fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 39672fc3fc0bSAndrii Nakryiko cand_id = (__u32)(long)hash_entry->value; 3968740e69c3SAndrii Nakryiko cand = btf_type_by_id(d->btf, cand_id); 3969d5caef5bSAndrii Nakryiko if (btf_equal_array(t, cand)) { 39702fc3fc0bSAndrii Nakryiko new_id = cand_id; 3971d5caef5bSAndrii Nakryiko break; 3972d5caef5bSAndrii Nakryiko } 3973d5caef5bSAndrii Nakryiko } 3974d5caef5bSAndrii Nakryiko break; 3975d5caef5bSAndrii Nakryiko } 3976d5caef5bSAndrii Nakryiko 3977d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC_PROTO: { 3978d5caef5bSAndrii Nakryiko struct btf_param *param; 3979d5caef5bSAndrii Nakryiko __u16 vlen; 3980d5caef5bSAndrii Nakryiko int i; 3981d5caef5bSAndrii Nakryiko 3982d5caef5bSAndrii Nakryiko ref_type_id = btf_dedup_ref_type(d, t->type); 3983d5caef5bSAndrii Nakryiko if (ref_type_id < 0) 3984d5caef5bSAndrii Nakryiko return ref_type_id; 3985d5caef5bSAndrii Nakryiko t->type = ref_type_id; 3986d5caef5bSAndrii Nakryiko 3987b03bc685SAndrii Nakryiko vlen = btf_vlen(t); 3988b03bc685SAndrii Nakryiko param = btf_params(t); 3989d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 3990d5caef5bSAndrii Nakryiko ref_type_id = btf_dedup_ref_type(d, param->type); 3991d5caef5bSAndrii Nakryiko if (ref_type_id < 0) 3992d5caef5bSAndrii Nakryiko return ref_type_id; 3993d5caef5bSAndrii Nakryiko param->type = ref_type_id; 3994d5caef5bSAndrii Nakryiko param++; 3995d5caef5bSAndrii Nakryiko } 3996d5caef5bSAndrii Nakryiko 3997d5caef5bSAndrii Nakryiko h = btf_hash_fnproto(t); 39982fc3fc0bSAndrii Nakryiko for_each_dedup_cand(d, hash_entry, h) { 39992fc3fc0bSAndrii Nakryiko cand_id = (__u32)(long)hash_entry->value; 4000740e69c3SAndrii Nakryiko cand = btf_type_by_id(d->btf, cand_id); 4001d5caef5bSAndrii Nakryiko if (btf_equal_fnproto(t, cand)) { 40022fc3fc0bSAndrii Nakryiko new_id = cand_id; 4003d5caef5bSAndrii Nakryiko break; 4004d5caef5bSAndrii Nakryiko } 4005d5caef5bSAndrii Nakryiko } 4006d5caef5bSAndrii Nakryiko break; 4007d5caef5bSAndrii Nakryiko } 4008d5caef5bSAndrii Nakryiko 4009d5caef5bSAndrii Nakryiko default: 4010d5caef5bSAndrii Nakryiko return -EINVAL; 4011d5caef5bSAndrii Nakryiko } 4012d5caef5bSAndrii Nakryiko 4013d5caef5bSAndrii Nakryiko d->map[type_id] = new_id; 4014d5caef5bSAndrii Nakryiko if (type_id == new_id && btf_dedup_table_add(d, h, type_id)) 4015d5caef5bSAndrii Nakryiko return -ENOMEM; 4016d5caef5bSAndrii Nakryiko 4017d5caef5bSAndrii Nakryiko return new_id; 4018d5caef5bSAndrii Nakryiko } 4019d5caef5bSAndrii Nakryiko 4020d5caef5bSAndrii Nakryiko static int btf_dedup_ref_types(struct btf_dedup *d) 4021d5caef5bSAndrii Nakryiko { 4022d5caef5bSAndrii Nakryiko int i, err; 4023d5caef5bSAndrii Nakryiko 4024d5caef5bSAndrii Nakryiko for (i = 1; i <= d->btf->nr_types; i++) { 4025d5caef5bSAndrii Nakryiko err = btf_dedup_ref_type(d, i); 4026d5caef5bSAndrii Nakryiko if (err < 0) 4027d5caef5bSAndrii Nakryiko return err; 4028d5caef5bSAndrii Nakryiko } 40292fc3fc0bSAndrii Nakryiko /* we won't need d->dedup_table anymore */ 40302fc3fc0bSAndrii Nakryiko hashmap__free(d->dedup_table); 40312fc3fc0bSAndrii Nakryiko d->dedup_table = NULL; 4032d5caef5bSAndrii Nakryiko return 0; 4033d5caef5bSAndrii Nakryiko } 4034d5caef5bSAndrii Nakryiko 4035d5caef5bSAndrii Nakryiko /* 4036d5caef5bSAndrii Nakryiko * Compact types. 4037d5caef5bSAndrii Nakryiko * 4038d5caef5bSAndrii Nakryiko * After we established for each type its corresponding canonical representative 4039d5caef5bSAndrii Nakryiko * type, we now can eliminate types that are not canonical and leave only 4040d5caef5bSAndrii Nakryiko * canonical ones layed out sequentially in memory by copying them over 4041d5caef5bSAndrii Nakryiko * duplicates. During compaction btf_dedup->hypot_map array is reused to store 4042d5caef5bSAndrii Nakryiko * a map from original type ID to a new compacted type ID, which will be used 4043d5caef5bSAndrii Nakryiko * during next phase to "fix up" type IDs, referenced from struct/union and 4044d5caef5bSAndrii Nakryiko * reference types. 4045d5caef5bSAndrii Nakryiko */ 4046d5caef5bSAndrii Nakryiko static int btf_dedup_compact_types(struct btf_dedup *d) 4047d5caef5bSAndrii Nakryiko { 4048740e69c3SAndrii Nakryiko __u32 *new_offs; 4049d5caef5bSAndrii Nakryiko __u32 next_type_id = 1; 4050740e69c3SAndrii Nakryiko void *p; 4051d5caef5bSAndrii Nakryiko int i, len; 4052d5caef5bSAndrii Nakryiko 4053d5caef5bSAndrii Nakryiko /* we are going to reuse hypot_map to store compaction remapping */ 4054d5caef5bSAndrii Nakryiko d->hypot_map[0] = 0; 4055d5caef5bSAndrii Nakryiko for (i = 1; i <= d->btf->nr_types; i++) 4056d5caef5bSAndrii Nakryiko d->hypot_map[i] = BTF_UNPROCESSED_ID; 4057d5caef5bSAndrii Nakryiko 4058740e69c3SAndrii Nakryiko p = d->btf->types_data; 4059d5caef5bSAndrii Nakryiko 4060d5caef5bSAndrii Nakryiko for (i = 1; i <= d->btf->nr_types; i++) { 4061d5caef5bSAndrii Nakryiko if (d->map[i] != i) 4062d5caef5bSAndrii Nakryiko continue; 4063d5caef5bSAndrii Nakryiko 4064740e69c3SAndrii Nakryiko len = btf_type_size(btf__type_by_id(d->btf, i)); 4065d5caef5bSAndrii Nakryiko if (len < 0) 4066d5caef5bSAndrii Nakryiko return len; 4067d5caef5bSAndrii Nakryiko 4068740e69c3SAndrii Nakryiko memmove(p, btf__type_by_id(d->btf, i), len); 4069d5caef5bSAndrii Nakryiko d->hypot_map[i] = next_type_id; 4070740e69c3SAndrii Nakryiko d->btf->type_offs[next_type_id] = p - d->btf->types_data; 4071d5caef5bSAndrii Nakryiko p += len; 4072d5caef5bSAndrii Nakryiko next_type_id++; 4073d5caef5bSAndrii Nakryiko } 4074d5caef5bSAndrii Nakryiko 4075d5caef5bSAndrii Nakryiko /* shrink struct btf's internal types index and update btf_header */ 4076d5caef5bSAndrii Nakryiko d->btf->nr_types = next_type_id - 1; 4077740e69c3SAndrii Nakryiko d->btf->type_offs_cap = d->btf->nr_types + 1; 4078740e69c3SAndrii Nakryiko d->btf->hdr->type_len = p - d->btf->types_data; 4079740e69c3SAndrii Nakryiko new_offs = libbpf_reallocarray(d->btf->type_offs, d->btf->type_offs_cap, 4080740e69c3SAndrii Nakryiko sizeof(*new_offs)); 4081740e69c3SAndrii Nakryiko if (!new_offs) 4082d5caef5bSAndrii Nakryiko return -ENOMEM; 4083740e69c3SAndrii Nakryiko d->btf->type_offs = new_offs; 4084919d2b1dSAndrii Nakryiko d->btf->hdr->str_off = d->btf->hdr->type_len; 4085b8604247SAndrii Nakryiko d->btf->raw_size = d->btf->hdr->hdr_len + d->btf->hdr->type_len + d->btf->hdr->str_len; 4086d5caef5bSAndrii Nakryiko return 0; 4087d5caef5bSAndrii Nakryiko } 4088d5caef5bSAndrii Nakryiko 4089d5caef5bSAndrii Nakryiko /* 4090d5caef5bSAndrii Nakryiko * Figure out final (deduplicated and compacted) type ID for provided original 4091d5caef5bSAndrii Nakryiko * `type_id` by first resolving it into corresponding canonical type ID and 4092d5caef5bSAndrii Nakryiko * then mapping it to a deduplicated type ID, stored in btf_dedup->hypot_map, 4093d5caef5bSAndrii Nakryiko * which is populated during compaction phase. 4094d5caef5bSAndrii Nakryiko */ 4095d5caef5bSAndrii Nakryiko static int btf_dedup_remap_type_id(struct btf_dedup *d, __u32 type_id) 4096d5caef5bSAndrii Nakryiko { 4097d5caef5bSAndrii Nakryiko __u32 resolved_type_id, new_type_id; 4098d5caef5bSAndrii Nakryiko 4099d5caef5bSAndrii Nakryiko resolved_type_id = resolve_type_id(d, type_id); 4100d5caef5bSAndrii Nakryiko new_type_id = d->hypot_map[resolved_type_id]; 41015aab392cSAndrii Nakryiko if (new_type_id > BTF_MAX_NR_TYPES) 4102d5caef5bSAndrii Nakryiko return -EINVAL; 4103d5caef5bSAndrii Nakryiko return new_type_id; 4104d5caef5bSAndrii Nakryiko } 4105d5caef5bSAndrii Nakryiko 4106d5caef5bSAndrii Nakryiko /* 4107d5caef5bSAndrii Nakryiko * Remap referenced type IDs into deduped type IDs. 4108d5caef5bSAndrii Nakryiko * 4109d5caef5bSAndrii Nakryiko * After BTF types are deduplicated and compacted, their final type IDs may 4110d5caef5bSAndrii Nakryiko * differ from original ones. The map from original to a corresponding 4111d5caef5bSAndrii Nakryiko * deduped type ID is stored in btf_dedup->hypot_map and is populated during 4112d5caef5bSAndrii Nakryiko * compaction phase. During remapping phase we are rewriting all type IDs 4113d5caef5bSAndrii Nakryiko * referenced from any BTF type (e.g., struct fields, func proto args, etc) to 4114d5caef5bSAndrii Nakryiko * their final deduped type IDs. 4115d5caef5bSAndrii Nakryiko */ 4116d5caef5bSAndrii Nakryiko static int btf_dedup_remap_type(struct btf_dedup *d, __u32 type_id) 4117d5caef5bSAndrii Nakryiko { 4118740e69c3SAndrii Nakryiko struct btf_type *t = btf_type_by_id(d->btf, type_id); 4119d5caef5bSAndrii Nakryiko int i, r; 4120d5caef5bSAndrii Nakryiko 4121b03bc685SAndrii Nakryiko switch (btf_kind(t)) { 4122d5caef5bSAndrii Nakryiko case BTF_KIND_INT: 4123d5caef5bSAndrii Nakryiko case BTF_KIND_ENUM: 4124d5caef5bSAndrii Nakryiko break; 4125d5caef5bSAndrii Nakryiko 4126d5caef5bSAndrii Nakryiko case BTF_KIND_FWD: 4127d5caef5bSAndrii Nakryiko case BTF_KIND_CONST: 4128d5caef5bSAndrii Nakryiko case BTF_KIND_VOLATILE: 4129d5caef5bSAndrii Nakryiko case BTF_KIND_RESTRICT: 4130d5caef5bSAndrii Nakryiko case BTF_KIND_PTR: 4131d5caef5bSAndrii Nakryiko case BTF_KIND_TYPEDEF: 4132d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC: 4133189cf5a4SAndrii Nakryiko case BTF_KIND_VAR: 4134d5caef5bSAndrii Nakryiko r = btf_dedup_remap_type_id(d, t->type); 4135d5caef5bSAndrii Nakryiko if (r < 0) 4136d5caef5bSAndrii Nakryiko return r; 4137d5caef5bSAndrii Nakryiko t->type = r; 4138d5caef5bSAndrii Nakryiko break; 4139d5caef5bSAndrii Nakryiko 4140d5caef5bSAndrii Nakryiko case BTF_KIND_ARRAY: { 4141b03bc685SAndrii Nakryiko struct btf_array *arr_info = btf_array(t); 4142d5caef5bSAndrii Nakryiko 4143d5caef5bSAndrii Nakryiko r = btf_dedup_remap_type_id(d, arr_info->type); 4144d5caef5bSAndrii Nakryiko if (r < 0) 4145d5caef5bSAndrii Nakryiko return r; 4146d5caef5bSAndrii Nakryiko arr_info->type = r; 4147d5caef5bSAndrii Nakryiko r = btf_dedup_remap_type_id(d, arr_info->index_type); 4148d5caef5bSAndrii Nakryiko if (r < 0) 4149d5caef5bSAndrii Nakryiko return r; 4150d5caef5bSAndrii Nakryiko arr_info->index_type = r; 4151d5caef5bSAndrii Nakryiko break; 4152d5caef5bSAndrii Nakryiko } 4153d5caef5bSAndrii Nakryiko 4154d5caef5bSAndrii Nakryiko case BTF_KIND_STRUCT: 4155d5caef5bSAndrii Nakryiko case BTF_KIND_UNION: { 4156b03bc685SAndrii Nakryiko struct btf_member *member = btf_members(t); 4157b03bc685SAndrii Nakryiko __u16 vlen = btf_vlen(t); 4158d5caef5bSAndrii Nakryiko 4159d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 4160d5caef5bSAndrii Nakryiko r = btf_dedup_remap_type_id(d, member->type); 4161d5caef5bSAndrii Nakryiko if (r < 0) 4162d5caef5bSAndrii Nakryiko return r; 4163d5caef5bSAndrii Nakryiko member->type = r; 4164d5caef5bSAndrii Nakryiko member++; 4165d5caef5bSAndrii Nakryiko } 4166d5caef5bSAndrii Nakryiko break; 4167d5caef5bSAndrii Nakryiko } 4168d5caef5bSAndrii Nakryiko 4169d5caef5bSAndrii Nakryiko case BTF_KIND_FUNC_PROTO: { 4170b03bc685SAndrii Nakryiko struct btf_param *param = btf_params(t); 4171b03bc685SAndrii Nakryiko __u16 vlen = btf_vlen(t); 4172d5caef5bSAndrii Nakryiko 4173d5caef5bSAndrii Nakryiko r = btf_dedup_remap_type_id(d, t->type); 4174d5caef5bSAndrii Nakryiko if (r < 0) 4175d5caef5bSAndrii Nakryiko return r; 4176d5caef5bSAndrii Nakryiko t->type = r; 4177d5caef5bSAndrii Nakryiko 4178d5caef5bSAndrii Nakryiko for (i = 0; i < vlen; i++) { 4179d5caef5bSAndrii Nakryiko r = btf_dedup_remap_type_id(d, param->type); 4180d5caef5bSAndrii Nakryiko if (r < 0) 4181d5caef5bSAndrii Nakryiko return r; 4182d5caef5bSAndrii Nakryiko param->type = r; 4183d5caef5bSAndrii Nakryiko param++; 4184d5caef5bSAndrii Nakryiko } 4185d5caef5bSAndrii Nakryiko break; 4186d5caef5bSAndrii Nakryiko } 4187d5caef5bSAndrii Nakryiko 4188189cf5a4SAndrii Nakryiko case BTF_KIND_DATASEC: { 4189b03bc685SAndrii Nakryiko struct btf_var_secinfo *var = btf_var_secinfos(t); 4190b03bc685SAndrii Nakryiko __u16 vlen = btf_vlen(t); 4191189cf5a4SAndrii Nakryiko 4192189cf5a4SAndrii Nakryiko for (i = 0; i < vlen; i++) { 4193189cf5a4SAndrii Nakryiko r = btf_dedup_remap_type_id(d, var->type); 4194189cf5a4SAndrii Nakryiko if (r < 0) 4195189cf5a4SAndrii Nakryiko return r; 4196189cf5a4SAndrii Nakryiko var->type = r; 4197189cf5a4SAndrii Nakryiko var++; 4198189cf5a4SAndrii Nakryiko } 4199189cf5a4SAndrii Nakryiko break; 4200189cf5a4SAndrii Nakryiko } 4201189cf5a4SAndrii Nakryiko 4202d5caef5bSAndrii Nakryiko default: 4203d5caef5bSAndrii Nakryiko return -EINVAL; 4204d5caef5bSAndrii Nakryiko } 4205d5caef5bSAndrii Nakryiko 4206d5caef5bSAndrii Nakryiko return 0; 4207d5caef5bSAndrii Nakryiko } 4208d5caef5bSAndrii Nakryiko 4209d5caef5bSAndrii Nakryiko static int btf_dedup_remap_types(struct btf_dedup *d) 4210d5caef5bSAndrii Nakryiko { 4211d5caef5bSAndrii Nakryiko int i, r; 4212d5caef5bSAndrii Nakryiko 4213d5caef5bSAndrii Nakryiko for (i = 1; i <= d->btf->nr_types; i++) { 4214d5caef5bSAndrii Nakryiko r = btf_dedup_remap_type(d, i); 4215d5caef5bSAndrii Nakryiko if (r < 0) 4216d5caef5bSAndrii Nakryiko return r; 4217d5caef5bSAndrii Nakryiko } 4218d5caef5bSAndrii Nakryiko return 0; 4219d5caef5bSAndrii Nakryiko } 4220fb2426adSMartin KaFai Lau 4221fb2426adSMartin KaFai Lau /* 4222fb2426adSMartin KaFai Lau * Probe few well-known locations for vmlinux kernel image and try to load BTF 4223fb2426adSMartin KaFai Lau * data out of it to use for target BTF. 4224fb2426adSMartin KaFai Lau */ 4225fb2426adSMartin KaFai Lau struct btf *libbpf_find_kernel_btf(void) 4226fb2426adSMartin KaFai Lau { 4227fb2426adSMartin KaFai Lau struct { 4228fb2426adSMartin KaFai Lau const char *path_fmt; 4229fb2426adSMartin KaFai Lau bool raw_btf; 4230fb2426adSMartin KaFai Lau } locations[] = { 4231fb2426adSMartin KaFai Lau /* try canonical vmlinux BTF through sysfs first */ 4232fb2426adSMartin KaFai Lau { "/sys/kernel/btf/vmlinux", true /* raw BTF */ }, 4233fb2426adSMartin KaFai Lau /* fall back to trying to find vmlinux ELF on disk otherwise */ 4234fb2426adSMartin KaFai Lau { "/boot/vmlinux-%1$s" }, 4235fb2426adSMartin KaFai Lau { "/lib/modules/%1$s/vmlinux-%1$s" }, 4236fb2426adSMartin KaFai Lau { "/lib/modules/%1$s/build/vmlinux" }, 4237fb2426adSMartin KaFai Lau { "/usr/lib/modules/%1$s/kernel/vmlinux" }, 4238fb2426adSMartin KaFai Lau { "/usr/lib/debug/boot/vmlinux-%1$s" }, 4239fb2426adSMartin KaFai Lau { "/usr/lib/debug/boot/vmlinux-%1$s.debug" }, 4240fb2426adSMartin KaFai Lau { "/usr/lib/debug/lib/modules/%1$s/vmlinux" }, 4241fb2426adSMartin KaFai Lau }; 4242fb2426adSMartin KaFai Lau char path[PATH_MAX + 1]; 4243fb2426adSMartin KaFai Lau struct utsname buf; 4244fb2426adSMartin KaFai Lau struct btf *btf; 4245fb2426adSMartin KaFai Lau int i; 4246fb2426adSMartin KaFai Lau 4247fb2426adSMartin KaFai Lau uname(&buf); 4248fb2426adSMartin KaFai Lau 4249fb2426adSMartin KaFai Lau for (i = 0; i < ARRAY_SIZE(locations); i++) { 4250fb2426adSMartin KaFai Lau snprintf(path, PATH_MAX, locations[i].path_fmt, buf.release); 4251fb2426adSMartin KaFai Lau 4252fb2426adSMartin KaFai Lau if (access(path, R_OK)) 4253fb2426adSMartin KaFai Lau continue; 4254fb2426adSMartin KaFai Lau 4255fb2426adSMartin KaFai Lau if (locations[i].raw_btf) 425694a1feddSAndrii Nakryiko btf = btf__parse_raw(path); 4257fb2426adSMartin KaFai Lau else 4258fb2426adSMartin KaFai Lau btf = btf__parse_elf(path, NULL); 4259fb2426adSMartin KaFai Lau 4260fb2426adSMartin KaFai Lau pr_debug("loading kernel BTF '%s': %ld\n", 4261fb2426adSMartin KaFai Lau path, IS_ERR(btf) ? PTR_ERR(btf) : 0); 4262fb2426adSMartin KaFai Lau if (IS_ERR(btf)) 4263fb2426adSMartin KaFai Lau continue; 4264fb2426adSMartin KaFai Lau 4265fb2426adSMartin KaFai Lau return btf; 4266fb2426adSMartin KaFai Lau } 4267fb2426adSMartin KaFai Lau 4268fb2426adSMartin KaFai Lau pr_warn("failed to find valid kernel BTF\n"); 4269fb2426adSMartin KaFai Lau return ERR_PTR(-ESRCH); 4270fb2426adSMartin KaFai Lau } 4271