10a14842fSEric Dumazet /* bpf_jit_comp.c : BPF JIT compiler 20a14842fSEric Dumazet * 33b58908aSEric Dumazet * Copyright (C) 2011-2013 Eric Dumazet (eric.dumazet@gmail.com) 462258278SAlexei Starovoitov * Internal BPF Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 50a14842fSEric Dumazet * 60a14842fSEric Dumazet * This program is free software; you can redistribute it and/or 70a14842fSEric Dumazet * modify it under the terms of the GNU General Public License 80a14842fSEric Dumazet * as published by the Free Software Foundation; version 2 90a14842fSEric Dumazet * of the License. 100a14842fSEric Dumazet */ 110a14842fSEric Dumazet #include <linux/netdevice.h> 120a14842fSEric Dumazet #include <linux/filter.h> 13855ddb56SEric Dumazet #include <linux/if_vlan.h> 14738cbe72SDaniel Borkmann #include <asm/cacheflush.h> 15b52f00e6SAlexei Starovoitov #include <linux/bpf.h> 160a14842fSEric Dumazet 170a14842fSEric Dumazet int bpf_jit_enable __read_mostly; 180a14842fSEric Dumazet 190a14842fSEric Dumazet /* 200a14842fSEric Dumazet * assembly code in arch/x86/net/bpf_jit.S 210a14842fSEric Dumazet */ 2262258278SAlexei Starovoitov extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; 23a998d434SJan Seiffert extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[]; 2462258278SAlexei Starovoitov extern u8 sk_load_byte_positive_offset[]; 25a998d434SJan Seiffert extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[]; 2662258278SAlexei Starovoitov extern u8 sk_load_byte_negative_offset[]; 270a14842fSEric Dumazet 285cccc702SJoe Perches static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) 290a14842fSEric Dumazet { 300a14842fSEric Dumazet if (len == 1) 310a14842fSEric Dumazet *ptr = bytes; 320a14842fSEric Dumazet else if (len == 2) 330a14842fSEric Dumazet *(u16 *)ptr = bytes; 340a14842fSEric Dumazet else { 350a14842fSEric Dumazet *(u32 *)ptr = bytes; 360a14842fSEric Dumazet barrier(); 370a14842fSEric Dumazet } 380a14842fSEric Dumazet return ptr + len; 390a14842fSEric Dumazet } 400a14842fSEric Dumazet 41b52f00e6SAlexei Starovoitov #define EMIT(bytes, len) \ 42b52f00e6SAlexei Starovoitov do { prog = emit_code(prog, bytes, len); cnt += len; } while (0) 430a14842fSEric Dumazet 440a14842fSEric Dumazet #define EMIT1(b1) EMIT(b1, 1) 450a14842fSEric Dumazet #define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2) 460a14842fSEric Dumazet #define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3) 470a14842fSEric Dumazet #define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4) 4862258278SAlexei Starovoitov #define EMIT1_off32(b1, off) \ 4962258278SAlexei Starovoitov do {EMIT1(b1); EMIT(off, 4); } while (0) 5062258278SAlexei Starovoitov #define EMIT2_off32(b1, b2, off) \ 5162258278SAlexei Starovoitov do {EMIT2(b1, b2); EMIT(off, 4); } while (0) 5262258278SAlexei Starovoitov #define EMIT3_off32(b1, b2, b3, off) \ 5362258278SAlexei Starovoitov do {EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) 5462258278SAlexei Starovoitov #define EMIT4_off32(b1, b2, b3, b4, off) \ 5562258278SAlexei Starovoitov do {EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) 560a14842fSEric Dumazet 575cccc702SJoe Perches static bool is_imm8(int value) 580a14842fSEric Dumazet { 590a14842fSEric Dumazet return value <= 127 && value >= -128; 600a14842fSEric Dumazet } 610a14842fSEric Dumazet 625cccc702SJoe Perches static bool is_simm32(s64 value) 630a14842fSEric Dumazet { 6462258278SAlexei Starovoitov return value == (s64) (s32) value; 650a14842fSEric Dumazet } 660a14842fSEric Dumazet 67e430f34eSAlexei Starovoitov /* mov dst, src */ 68e430f34eSAlexei Starovoitov #define EMIT_mov(DST, SRC) \ 69e430f34eSAlexei Starovoitov do {if (DST != SRC) \ 70e430f34eSAlexei Starovoitov EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ 710a14842fSEric Dumazet } while (0) 720a14842fSEric Dumazet 7362258278SAlexei Starovoitov static int bpf_size_to_x86_bytes(int bpf_size) 7462258278SAlexei Starovoitov { 7562258278SAlexei Starovoitov if (bpf_size == BPF_W) 7662258278SAlexei Starovoitov return 4; 7762258278SAlexei Starovoitov else if (bpf_size == BPF_H) 7862258278SAlexei Starovoitov return 2; 7962258278SAlexei Starovoitov else if (bpf_size == BPF_B) 8062258278SAlexei Starovoitov return 1; 8162258278SAlexei Starovoitov else if (bpf_size == BPF_DW) 8262258278SAlexei Starovoitov return 4; /* imm32 */ 8362258278SAlexei Starovoitov else 8462258278SAlexei Starovoitov return 0; 8562258278SAlexei Starovoitov } 8662258278SAlexei Starovoitov 870a14842fSEric Dumazet /* list of x86 cond jumps opcodes (. + s8) 880a14842fSEric Dumazet * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32) 890a14842fSEric Dumazet */ 900a14842fSEric Dumazet #define X86_JB 0x72 910a14842fSEric Dumazet #define X86_JAE 0x73 920a14842fSEric Dumazet #define X86_JE 0x74 930a14842fSEric Dumazet #define X86_JNE 0x75 940a14842fSEric Dumazet #define X86_JBE 0x76 950a14842fSEric Dumazet #define X86_JA 0x77 9662258278SAlexei Starovoitov #define X86_JGE 0x7D 9762258278SAlexei Starovoitov #define X86_JG 0x7F 980a14842fSEric Dumazet 995cccc702SJoe Perches static void bpf_flush_icache(void *start, void *end) 1000a14842fSEric Dumazet { 1010a14842fSEric Dumazet mm_segment_t old_fs = get_fs(); 1020a14842fSEric Dumazet 1030a14842fSEric Dumazet set_fs(KERNEL_DS); 1040a14842fSEric Dumazet smp_wmb(); 1050a14842fSEric Dumazet flush_icache_range((unsigned long)start, (unsigned long)end); 1060a14842fSEric Dumazet set_fs(old_fs); 1070a14842fSEric Dumazet } 1080a14842fSEric Dumazet 109a998d434SJan Seiffert #define CHOOSE_LOAD_FUNC(K, func) \ 110a998d434SJan Seiffert ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) 1110a14842fSEric Dumazet 11262258278SAlexei Starovoitov /* pick a register outside of BPF range for JIT internal work */ 113959a7579SDaniel Borkmann #define AUX_REG (MAX_BPF_JIT_REG + 1) 11462258278SAlexei Starovoitov 115959a7579SDaniel Borkmann /* The following table maps BPF registers to x64 registers. 116959a7579SDaniel Borkmann * 117959a7579SDaniel Borkmann * x64 register r12 is unused, since if used as base address 118959a7579SDaniel Borkmann * register in load/store instructions, it always needs an 119959a7579SDaniel Borkmann * extra byte of encoding and is callee saved. 120959a7579SDaniel Borkmann * 121959a7579SDaniel Borkmann * r9 caches skb->len - skb->data_len 122959a7579SDaniel Borkmann * r10 caches skb->data, and used for blinding (if enabled) 12362258278SAlexei Starovoitov */ 12462258278SAlexei Starovoitov static const int reg2hex[] = { 12562258278SAlexei Starovoitov [BPF_REG_0] = 0, /* rax */ 12662258278SAlexei Starovoitov [BPF_REG_1] = 7, /* rdi */ 12762258278SAlexei Starovoitov [BPF_REG_2] = 6, /* rsi */ 12862258278SAlexei Starovoitov [BPF_REG_3] = 2, /* rdx */ 12962258278SAlexei Starovoitov [BPF_REG_4] = 1, /* rcx */ 13062258278SAlexei Starovoitov [BPF_REG_5] = 0, /* r8 */ 13162258278SAlexei Starovoitov [BPF_REG_6] = 3, /* rbx callee saved */ 13262258278SAlexei Starovoitov [BPF_REG_7] = 5, /* r13 callee saved */ 13362258278SAlexei Starovoitov [BPF_REG_8] = 6, /* r14 callee saved */ 13462258278SAlexei Starovoitov [BPF_REG_9] = 7, /* r15 callee saved */ 13562258278SAlexei Starovoitov [BPF_REG_FP] = 5, /* rbp readonly */ 136959a7579SDaniel Borkmann [BPF_REG_AX] = 2, /* r10 temp register */ 13762258278SAlexei Starovoitov [AUX_REG] = 3, /* r11 temp register */ 13862258278SAlexei Starovoitov }; 13962258278SAlexei Starovoitov 14062258278SAlexei Starovoitov /* is_ereg() == true if BPF register 'reg' maps to x64 r8..r15 14162258278SAlexei Starovoitov * which need extra byte of encoding. 14262258278SAlexei Starovoitov * rax,rcx,...,rbp have simpler encoding 14362258278SAlexei Starovoitov */ 1445cccc702SJoe Perches static bool is_ereg(u32 reg) 14562258278SAlexei Starovoitov { 146d148134bSJoe Perches return (1 << reg) & (BIT(BPF_REG_5) | 147d148134bSJoe Perches BIT(AUX_REG) | 148d148134bSJoe Perches BIT(BPF_REG_7) | 149d148134bSJoe Perches BIT(BPF_REG_8) | 150959a7579SDaniel Borkmann BIT(BPF_REG_9) | 151959a7579SDaniel Borkmann BIT(BPF_REG_AX)); 15262258278SAlexei Starovoitov } 15362258278SAlexei Starovoitov 15462258278SAlexei Starovoitov /* add modifiers if 'reg' maps to x64 registers r8..r15 */ 1555cccc702SJoe Perches static u8 add_1mod(u8 byte, u32 reg) 15662258278SAlexei Starovoitov { 15762258278SAlexei Starovoitov if (is_ereg(reg)) 15862258278SAlexei Starovoitov byte |= 1; 15962258278SAlexei Starovoitov return byte; 16062258278SAlexei Starovoitov } 16162258278SAlexei Starovoitov 1625cccc702SJoe Perches static u8 add_2mod(u8 byte, u32 r1, u32 r2) 16362258278SAlexei Starovoitov { 16462258278SAlexei Starovoitov if (is_ereg(r1)) 16562258278SAlexei Starovoitov byte |= 1; 16662258278SAlexei Starovoitov if (is_ereg(r2)) 16762258278SAlexei Starovoitov byte |= 4; 16862258278SAlexei Starovoitov return byte; 16962258278SAlexei Starovoitov } 17062258278SAlexei Starovoitov 171e430f34eSAlexei Starovoitov /* encode 'dst_reg' register into x64 opcode 'byte' */ 1725cccc702SJoe Perches static u8 add_1reg(u8 byte, u32 dst_reg) 17362258278SAlexei Starovoitov { 174e430f34eSAlexei Starovoitov return byte + reg2hex[dst_reg]; 17562258278SAlexei Starovoitov } 17662258278SAlexei Starovoitov 177e430f34eSAlexei Starovoitov /* encode 'dst_reg' and 'src_reg' registers into x64 opcode 'byte' */ 1785cccc702SJoe Perches static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) 17962258278SAlexei Starovoitov { 180e430f34eSAlexei Starovoitov return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); 18162258278SAlexei Starovoitov } 18262258278SAlexei Starovoitov 183738cbe72SDaniel Borkmann static void jit_fill_hole(void *area, unsigned int size) 184738cbe72SDaniel Borkmann { 185738cbe72SDaniel Borkmann /* fill whole space with int3 instructions */ 186738cbe72SDaniel Borkmann memset(area, 0xcc, size); 187738cbe72SDaniel Borkmann } 188738cbe72SDaniel Borkmann 189f3c2af7bSAlexei Starovoitov struct jit_context { 190769e0de6SAlexei Starovoitov int cleanup_addr; /* epilogue code offset */ 19162258278SAlexei Starovoitov bool seen_ld_abs; 192959a7579SDaniel Borkmann bool seen_ax_reg; 193f3c2af7bSAlexei Starovoitov }; 194f3c2af7bSAlexei Starovoitov 195e0ee9c12SAlexei Starovoitov /* maximum number of bytes emitted while JITing one eBPF insn */ 196e0ee9c12SAlexei Starovoitov #define BPF_MAX_INSN_SIZE 128 197e0ee9c12SAlexei Starovoitov #define BPF_INSN_SAFETY 64 198e0ee9c12SAlexei Starovoitov 199b52f00e6SAlexei Starovoitov #define STACKSIZE \ 200b52f00e6SAlexei Starovoitov (MAX_BPF_STACK + \ 201b52f00e6SAlexei Starovoitov 32 /* space for rbx, r13, r14, r15 */ + \ 202b52f00e6SAlexei Starovoitov 8 /* space for skb_copy_bits() buffer */) 203b52f00e6SAlexei Starovoitov 2048b614aebSDaniel Borkmann #define PROLOGUE_SIZE 48 205b52f00e6SAlexei Starovoitov 206b52f00e6SAlexei Starovoitov /* emit x64 prologue code for BPF program and check it's size. 207b52f00e6SAlexei Starovoitov * bpf_tail_call helper will skip it while jumping into another program 208b52f00e6SAlexei Starovoitov */ 209b52f00e6SAlexei Starovoitov static void emit_prologue(u8 **pprog) 2100a14842fSEric Dumazet { 211b52f00e6SAlexei Starovoitov u8 *prog = *pprog; 212b52f00e6SAlexei Starovoitov int cnt = 0; 2130a14842fSEric Dumazet 21462258278SAlexei Starovoitov EMIT1(0x55); /* push rbp */ 21562258278SAlexei Starovoitov EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */ 2160a14842fSEric Dumazet 217b52f00e6SAlexei Starovoitov /* sub rsp, STACKSIZE */ 218b52f00e6SAlexei Starovoitov EMIT3_off32(0x48, 0x81, 0xEC, STACKSIZE); 2190a14842fSEric Dumazet 22062258278SAlexei Starovoitov /* all classic BPF filters use R6(rbx) save it */ 22162258278SAlexei Starovoitov 22262258278SAlexei Starovoitov /* mov qword ptr [rbp-X],rbx */ 223b52f00e6SAlexei Starovoitov EMIT3_off32(0x48, 0x89, 0x9D, -STACKSIZE); 22462258278SAlexei Starovoitov 2258fb575caSAlexei Starovoitov /* bpf_convert_filter() maps classic BPF register X to R7 and uses R8 22662258278SAlexei Starovoitov * as temporary, so all tcpdump filters need to spill/fill R7(r13) and 22762258278SAlexei Starovoitov * R8(r14). R9(r15) spill could be made conditional, but there is only 22862258278SAlexei Starovoitov * one 'bpf_error' return path out of helper functions inside bpf_jit.S 22962258278SAlexei Starovoitov * The overhead of extra spill is negligible for any filter other 23062258278SAlexei Starovoitov * than synthetic ones. Therefore not worth adding complexity. 2310a14842fSEric Dumazet */ 23262258278SAlexei Starovoitov 23362258278SAlexei Starovoitov /* mov qword ptr [rbp-X],r13 */ 234b52f00e6SAlexei Starovoitov EMIT3_off32(0x4C, 0x89, 0xAD, -STACKSIZE + 8); 23562258278SAlexei Starovoitov /* mov qword ptr [rbp-X],r14 */ 236b52f00e6SAlexei Starovoitov EMIT3_off32(0x4C, 0x89, 0xB5, -STACKSIZE + 16); 23762258278SAlexei Starovoitov /* mov qword ptr [rbp-X],r15 */ 238b52f00e6SAlexei Starovoitov EMIT3_off32(0x4C, 0x89, 0xBD, -STACKSIZE + 24); 23962258278SAlexei Starovoitov 2408b614aebSDaniel Borkmann /* Clear the tail call counter (tail_call_cnt): for eBPF tail calls 2418b614aebSDaniel Borkmann * we need to reset the counter to 0. It's done in two instructions, 2428b614aebSDaniel Borkmann * resetting rax register to 0 (xor on eax gets 0 extended), and 2438b614aebSDaniel Borkmann * moving it to the counter location. 2448b614aebSDaniel Borkmann */ 24562258278SAlexei Starovoitov 2468b614aebSDaniel Borkmann /* xor eax, eax */ 2478b614aebSDaniel Borkmann EMIT2(0x31, 0xc0); 2488b614aebSDaniel Borkmann /* mov qword ptr [rbp-X], rax */ 249b52f00e6SAlexei Starovoitov EMIT3_off32(0x48, 0x89, 0x85, -STACKSIZE + 32); 250b52f00e6SAlexei Starovoitov 251b52f00e6SAlexei Starovoitov BUILD_BUG_ON(cnt != PROLOGUE_SIZE); 252b52f00e6SAlexei Starovoitov *pprog = prog; 253b52f00e6SAlexei Starovoitov } 254b52f00e6SAlexei Starovoitov 255b52f00e6SAlexei Starovoitov /* generate the following code: 256b52f00e6SAlexei Starovoitov * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... 257b52f00e6SAlexei Starovoitov * if (index >= array->map.max_entries) 258b52f00e6SAlexei Starovoitov * goto out; 259b52f00e6SAlexei Starovoitov * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) 260b52f00e6SAlexei Starovoitov * goto out; 2612a36f0b9SWang Nan * prog = array->ptrs[index]; 262b52f00e6SAlexei Starovoitov * if (prog == NULL) 263b52f00e6SAlexei Starovoitov * goto out; 264b52f00e6SAlexei Starovoitov * goto *(prog->bpf_func + prologue_size); 265b52f00e6SAlexei Starovoitov * out: 266b52f00e6SAlexei Starovoitov */ 267b52f00e6SAlexei Starovoitov static void emit_bpf_tail_call(u8 **pprog) 268b52f00e6SAlexei Starovoitov { 269b52f00e6SAlexei Starovoitov u8 *prog = *pprog; 270b52f00e6SAlexei Starovoitov int label1, label2, label3; 271b52f00e6SAlexei Starovoitov int cnt = 0; 272b52f00e6SAlexei Starovoitov 273b52f00e6SAlexei Starovoitov /* rdi - pointer to ctx 274b52f00e6SAlexei Starovoitov * rsi - pointer to bpf_array 275b52f00e6SAlexei Starovoitov * rdx - index in bpf_array 276b52f00e6SAlexei Starovoitov */ 277b52f00e6SAlexei Starovoitov 278b52f00e6SAlexei Starovoitov /* if (index >= array->map.max_entries) 279b52f00e6SAlexei Starovoitov * goto out; 280b52f00e6SAlexei Starovoitov */ 281b52f00e6SAlexei Starovoitov EMIT4(0x48, 0x8B, 0x46, /* mov rax, qword ptr [rsi + 16] */ 282b52f00e6SAlexei Starovoitov offsetof(struct bpf_array, map.max_entries)); 283b52f00e6SAlexei Starovoitov EMIT3(0x48, 0x39, 0xD0); /* cmp rax, rdx */ 2842482abb9SDaniel Borkmann #define OFFSET1 47 /* number of bytes to jump */ 285b52f00e6SAlexei Starovoitov EMIT2(X86_JBE, OFFSET1); /* jbe out */ 286b52f00e6SAlexei Starovoitov label1 = cnt; 287b52f00e6SAlexei Starovoitov 288b52f00e6SAlexei Starovoitov /* if (tail_call_cnt > MAX_TAIL_CALL_CNT) 289b52f00e6SAlexei Starovoitov * goto out; 290b52f00e6SAlexei Starovoitov */ 291b52f00e6SAlexei Starovoitov EMIT2_off32(0x8B, 0x85, -STACKSIZE + 36); /* mov eax, dword ptr [rbp - 516] */ 292b52f00e6SAlexei Starovoitov EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ 2932482abb9SDaniel Borkmann #define OFFSET2 36 294b52f00e6SAlexei Starovoitov EMIT2(X86_JA, OFFSET2); /* ja out */ 295b52f00e6SAlexei Starovoitov label2 = cnt; 296b52f00e6SAlexei Starovoitov EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ 297b52f00e6SAlexei Starovoitov EMIT2_off32(0x89, 0x85, -STACKSIZE + 36); /* mov dword ptr [rbp - 516], eax */ 298b52f00e6SAlexei Starovoitov 2992a36f0b9SWang Nan /* prog = array->ptrs[index]; */ 3002482abb9SDaniel Borkmann EMIT4_off32(0x48, 0x8D, 0x84, 0xD6, /* lea rax, [rsi + rdx * 8 + offsetof(...)] */ 3012a36f0b9SWang Nan offsetof(struct bpf_array, ptrs)); 302b52f00e6SAlexei Starovoitov EMIT3(0x48, 0x8B, 0x00); /* mov rax, qword ptr [rax] */ 303b52f00e6SAlexei Starovoitov 304b52f00e6SAlexei Starovoitov /* if (prog == NULL) 305b52f00e6SAlexei Starovoitov * goto out; 306b52f00e6SAlexei Starovoitov */ 307b52f00e6SAlexei Starovoitov EMIT4(0x48, 0x83, 0xF8, 0x00); /* cmp rax, 0 */ 308b52f00e6SAlexei Starovoitov #define OFFSET3 10 309b52f00e6SAlexei Starovoitov EMIT2(X86_JE, OFFSET3); /* je out */ 310b52f00e6SAlexei Starovoitov label3 = cnt; 311b52f00e6SAlexei Starovoitov 312b52f00e6SAlexei Starovoitov /* goto *(prog->bpf_func + prologue_size); */ 313b52f00e6SAlexei Starovoitov EMIT4(0x48, 0x8B, 0x40, /* mov rax, qword ptr [rax + 32] */ 314b52f00e6SAlexei Starovoitov offsetof(struct bpf_prog, bpf_func)); 315b52f00e6SAlexei Starovoitov EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */ 316b52f00e6SAlexei Starovoitov 317b52f00e6SAlexei Starovoitov /* now we're ready to jump into next BPF program 318b52f00e6SAlexei Starovoitov * rdi == ctx (1st arg) 319b52f00e6SAlexei Starovoitov * rax == prog->bpf_func + prologue_size 320b52f00e6SAlexei Starovoitov */ 321b52f00e6SAlexei Starovoitov EMIT2(0xFF, 0xE0); /* jmp rax */ 322b52f00e6SAlexei Starovoitov 323b52f00e6SAlexei Starovoitov /* out: */ 324b52f00e6SAlexei Starovoitov BUILD_BUG_ON(cnt - label1 != OFFSET1); 325b52f00e6SAlexei Starovoitov BUILD_BUG_ON(cnt - label2 != OFFSET2); 326b52f00e6SAlexei Starovoitov BUILD_BUG_ON(cnt - label3 != OFFSET3); 327b52f00e6SAlexei Starovoitov *pprog = prog; 328b52f00e6SAlexei Starovoitov } 329b52f00e6SAlexei Starovoitov 3304e10df9aSAlexei Starovoitov 3314e10df9aSAlexei Starovoitov static void emit_load_skb_data_hlen(u8 **pprog) 3324e10df9aSAlexei Starovoitov { 3334e10df9aSAlexei Starovoitov u8 *prog = *pprog; 3344e10df9aSAlexei Starovoitov int cnt = 0; 3354e10df9aSAlexei Starovoitov 3364e10df9aSAlexei Starovoitov /* r9d = skb->len - skb->data_len (headlen) 3374e10df9aSAlexei Starovoitov * r10 = skb->data 3384e10df9aSAlexei Starovoitov */ 3394e10df9aSAlexei Starovoitov /* mov %r9d, off32(%rdi) */ 3404e10df9aSAlexei Starovoitov EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len)); 3414e10df9aSAlexei Starovoitov 3424e10df9aSAlexei Starovoitov /* sub %r9d, off32(%rdi) */ 3434e10df9aSAlexei Starovoitov EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len)); 3444e10df9aSAlexei Starovoitov 3454e10df9aSAlexei Starovoitov /* mov %r10, off32(%rdi) */ 3464e10df9aSAlexei Starovoitov EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data)); 3474e10df9aSAlexei Starovoitov *pprog = prog; 3484e10df9aSAlexei Starovoitov } 3494e10df9aSAlexei Starovoitov 350b52f00e6SAlexei Starovoitov static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, 351b52f00e6SAlexei Starovoitov int oldproglen, struct jit_context *ctx) 352b52f00e6SAlexei Starovoitov { 353b52f00e6SAlexei Starovoitov struct bpf_insn *insn = bpf_prog->insnsi; 354b52f00e6SAlexei Starovoitov int insn_cnt = bpf_prog->len; 355b52f00e6SAlexei Starovoitov bool seen_ld_abs = ctx->seen_ld_abs | (oldproglen == 0); 356959a7579SDaniel Borkmann bool seen_ax_reg = ctx->seen_ax_reg | (oldproglen == 0); 357b52f00e6SAlexei Starovoitov bool seen_exit = false; 358b52f00e6SAlexei Starovoitov u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; 359b52f00e6SAlexei Starovoitov int i, cnt = 0; 360b52f00e6SAlexei Starovoitov int proglen = 0; 361b52f00e6SAlexei Starovoitov u8 *prog = temp; 362b52f00e6SAlexei Starovoitov 363b52f00e6SAlexei Starovoitov emit_prologue(&prog); 364b52f00e6SAlexei Starovoitov 3654e10df9aSAlexei Starovoitov if (seen_ld_abs) 3664e10df9aSAlexei Starovoitov emit_load_skb_data_hlen(&prog); 36762258278SAlexei Starovoitov 36862258278SAlexei Starovoitov for (i = 0; i < insn_cnt; i++, insn++) { 369e430f34eSAlexei Starovoitov const s32 imm32 = insn->imm; 370e430f34eSAlexei Starovoitov u32 dst_reg = insn->dst_reg; 371e430f34eSAlexei Starovoitov u32 src_reg = insn->src_reg; 37262258278SAlexei Starovoitov u8 b1 = 0, b2 = 0, b3 = 0; 37362258278SAlexei Starovoitov s64 jmp_offset; 37462258278SAlexei Starovoitov u8 jmp_cond; 3754e10df9aSAlexei Starovoitov bool reload_skb_data; 37662258278SAlexei Starovoitov int ilen; 37762258278SAlexei Starovoitov u8 *func; 37862258278SAlexei Starovoitov 379959a7579SDaniel Borkmann if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX) 380959a7579SDaniel Borkmann ctx->seen_ax_reg = seen_ax_reg = true; 381959a7579SDaniel Borkmann 38262258278SAlexei Starovoitov switch (insn->code) { 38362258278SAlexei Starovoitov /* ALU */ 38462258278SAlexei Starovoitov case BPF_ALU | BPF_ADD | BPF_X: 38562258278SAlexei Starovoitov case BPF_ALU | BPF_SUB | BPF_X: 38662258278SAlexei Starovoitov case BPF_ALU | BPF_AND | BPF_X: 38762258278SAlexei Starovoitov case BPF_ALU | BPF_OR | BPF_X: 38862258278SAlexei Starovoitov case BPF_ALU | BPF_XOR | BPF_X: 38962258278SAlexei Starovoitov case BPF_ALU64 | BPF_ADD | BPF_X: 39062258278SAlexei Starovoitov case BPF_ALU64 | BPF_SUB | BPF_X: 39162258278SAlexei Starovoitov case BPF_ALU64 | BPF_AND | BPF_X: 39262258278SAlexei Starovoitov case BPF_ALU64 | BPF_OR | BPF_X: 39362258278SAlexei Starovoitov case BPF_ALU64 | BPF_XOR | BPF_X: 39462258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 39562258278SAlexei Starovoitov case BPF_ADD: b2 = 0x01; break; 39662258278SAlexei Starovoitov case BPF_SUB: b2 = 0x29; break; 39762258278SAlexei Starovoitov case BPF_AND: b2 = 0x21; break; 39862258278SAlexei Starovoitov case BPF_OR: b2 = 0x09; break; 39962258278SAlexei Starovoitov case BPF_XOR: b2 = 0x31; break; 40062258278SAlexei Starovoitov } 40162258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 402e430f34eSAlexei Starovoitov EMIT1(add_2mod(0x48, dst_reg, src_reg)); 403e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg) || is_ereg(src_reg)) 404e430f34eSAlexei Starovoitov EMIT1(add_2mod(0x40, dst_reg, src_reg)); 405e430f34eSAlexei Starovoitov EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); 4060a14842fSEric Dumazet break; 40762258278SAlexei Starovoitov 408e430f34eSAlexei Starovoitov /* mov dst, src */ 40962258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOV | BPF_X: 410e430f34eSAlexei Starovoitov EMIT_mov(dst_reg, src_reg); 41162258278SAlexei Starovoitov break; 41262258278SAlexei Starovoitov 413e430f34eSAlexei Starovoitov /* mov32 dst, src */ 41462258278SAlexei Starovoitov case BPF_ALU | BPF_MOV | BPF_X: 415e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 416e430f34eSAlexei Starovoitov EMIT1(add_2mod(0x40, dst_reg, src_reg)); 417e430f34eSAlexei Starovoitov EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); 41862258278SAlexei Starovoitov break; 41962258278SAlexei Starovoitov 420e430f34eSAlexei Starovoitov /* neg dst */ 42162258278SAlexei Starovoitov case BPF_ALU | BPF_NEG: 42262258278SAlexei Starovoitov case BPF_ALU64 | BPF_NEG: 42362258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 424e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 425e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg)) 426e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 427e430f34eSAlexei Starovoitov EMIT2(0xF7, add_1reg(0xD8, dst_reg)); 42862258278SAlexei Starovoitov break; 42962258278SAlexei Starovoitov 43062258278SAlexei Starovoitov case BPF_ALU | BPF_ADD | BPF_K: 43162258278SAlexei Starovoitov case BPF_ALU | BPF_SUB | BPF_K: 43262258278SAlexei Starovoitov case BPF_ALU | BPF_AND | BPF_K: 43362258278SAlexei Starovoitov case BPF_ALU | BPF_OR | BPF_K: 43462258278SAlexei Starovoitov case BPF_ALU | BPF_XOR | BPF_K: 43562258278SAlexei Starovoitov case BPF_ALU64 | BPF_ADD | BPF_K: 43662258278SAlexei Starovoitov case BPF_ALU64 | BPF_SUB | BPF_K: 43762258278SAlexei Starovoitov case BPF_ALU64 | BPF_AND | BPF_K: 43862258278SAlexei Starovoitov case BPF_ALU64 | BPF_OR | BPF_K: 43962258278SAlexei Starovoitov case BPF_ALU64 | BPF_XOR | BPF_K: 44062258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 441e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 442e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg)) 443e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 44462258278SAlexei Starovoitov 44562258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 44662258278SAlexei Starovoitov case BPF_ADD: b3 = 0xC0; break; 44762258278SAlexei Starovoitov case BPF_SUB: b3 = 0xE8; break; 44862258278SAlexei Starovoitov case BPF_AND: b3 = 0xE0; break; 44962258278SAlexei Starovoitov case BPF_OR: b3 = 0xC8; break; 45062258278SAlexei Starovoitov case BPF_XOR: b3 = 0xF0; break; 45162258278SAlexei Starovoitov } 45262258278SAlexei Starovoitov 453e430f34eSAlexei Starovoitov if (is_imm8(imm32)) 454e430f34eSAlexei Starovoitov EMIT3(0x83, add_1reg(b3, dst_reg), imm32); 45562258278SAlexei Starovoitov else 456e430f34eSAlexei Starovoitov EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); 45762258278SAlexei Starovoitov break; 45862258278SAlexei Starovoitov 45962258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOV | BPF_K: 46062258278SAlexei Starovoitov /* optimization: if imm32 is positive, 46162258278SAlexei Starovoitov * use 'mov eax, imm32' (which zero-extends imm32) 46262258278SAlexei Starovoitov * to save 2 bytes 463d00a9dd2SEric Dumazet */ 464e430f34eSAlexei Starovoitov if (imm32 < 0) { 46562258278SAlexei Starovoitov /* 'mov rax, imm32' sign extends imm32 */ 466e430f34eSAlexei Starovoitov b1 = add_1mod(0x48, dst_reg); 46762258278SAlexei Starovoitov b2 = 0xC7; 46862258278SAlexei Starovoitov b3 = 0xC0; 469e430f34eSAlexei Starovoitov EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); 470aee636c4SEric Dumazet break; 471aee636c4SEric Dumazet } 4723b58908aSEric Dumazet 47362258278SAlexei Starovoitov case BPF_ALU | BPF_MOV | BPF_K: 474606c88a8SDaniel Borkmann /* optimization: if imm32 is zero, use 'xor <dst>,<dst>' 475606c88a8SDaniel Borkmann * to save 3 bytes. 476606c88a8SDaniel Borkmann */ 477606c88a8SDaniel Borkmann if (imm32 == 0) { 478606c88a8SDaniel Borkmann if (is_ereg(dst_reg)) 479606c88a8SDaniel Borkmann EMIT1(add_2mod(0x40, dst_reg, dst_reg)); 480606c88a8SDaniel Borkmann b2 = 0x31; /* xor */ 481606c88a8SDaniel Borkmann b3 = 0xC0; 482606c88a8SDaniel Borkmann EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); 483606c88a8SDaniel Borkmann break; 484606c88a8SDaniel Borkmann } 485606c88a8SDaniel Borkmann 48662258278SAlexei Starovoitov /* mov %eax, imm32 */ 487e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 488e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 489e430f34eSAlexei Starovoitov EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); 49062258278SAlexei Starovoitov break; 49162258278SAlexei Starovoitov 49202ab695bSAlexei Starovoitov case BPF_LD | BPF_IMM | BPF_DW: 49302ab695bSAlexei Starovoitov if (insn[1].code != 0 || insn[1].src_reg != 0 || 49402ab695bSAlexei Starovoitov insn[1].dst_reg != 0 || insn[1].off != 0) { 49502ab695bSAlexei Starovoitov /* verifier must catch invalid insns */ 49602ab695bSAlexei Starovoitov pr_err("invalid BPF_LD_IMM64 insn\n"); 49702ab695bSAlexei Starovoitov return -EINVAL; 49802ab695bSAlexei Starovoitov } 49902ab695bSAlexei Starovoitov 500606c88a8SDaniel Borkmann /* optimization: if imm64 is zero, use 'xor <dst>,<dst>' 501606c88a8SDaniel Borkmann * to save 7 bytes. 502606c88a8SDaniel Borkmann */ 503606c88a8SDaniel Borkmann if (insn[0].imm == 0 && insn[1].imm == 0) { 504606c88a8SDaniel Borkmann b1 = add_2mod(0x48, dst_reg, dst_reg); 505606c88a8SDaniel Borkmann b2 = 0x31; /* xor */ 506606c88a8SDaniel Borkmann b3 = 0xC0; 507606c88a8SDaniel Borkmann EMIT3(b1, b2, add_2reg(b3, dst_reg, dst_reg)); 508606c88a8SDaniel Borkmann 509606c88a8SDaniel Borkmann insn++; 510606c88a8SDaniel Borkmann i++; 511606c88a8SDaniel Borkmann break; 512606c88a8SDaniel Borkmann } 513606c88a8SDaniel Borkmann 51402ab695bSAlexei Starovoitov /* movabsq %rax, imm64 */ 51502ab695bSAlexei Starovoitov EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); 51602ab695bSAlexei Starovoitov EMIT(insn[0].imm, 4); 51702ab695bSAlexei Starovoitov EMIT(insn[1].imm, 4); 51802ab695bSAlexei Starovoitov 51902ab695bSAlexei Starovoitov insn++; 52002ab695bSAlexei Starovoitov i++; 52102ab695bSAlexei Starovoitov break; 52202ab695bSAlexei Starovoitov 523e430f34eSAlexei Starovoitov /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ 52462258278SAlexei Starovoitov case BPF_ALU | BPF_MOD | BPF_X: 52562258278SAlexei Starovoitov case BPF_ALU | BPF_DIV | BPF_X: 52662258278SAlexei Starovoitov case BPF_ALU | BPF_MOD | BPF_K: 52762258278SAlexei Starovoitov case BPF_ALU | BPF_DIV | BPF_K: 52862258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOD | BPF_X: 52962258278SAlexei Starovoitov case BPF_ALU64 | BPF_DIV | BPF_X: 53062258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOD | BPF_K: 53162258278SAlexei Starovoitov case BPF_ALU64 | BPF_DIV | BPF_K: 53262258278SAlexei Starovoitov EMIT1(0x50); /* push rax */ 53362258278SAlexei Starovoitov EMIT1(0x52); /* push rdx */ 53462258278SAlexei Starovoitov 53562258278SAlexei Starovoitov if (BPF_SRC(insn->code) == BPF_X) 536e430f34eSAlexei Starovoitov /* mov r11, src_reg */ 537e430f34eSAlexei Starovoitov EMIT_mov(AUX_REG, src_reg); 53862258278SAlexei Starovoitov else 539e430f34eSAlexei Starovoitov /* mov r11, imm32 */ 540e430f34eSAlexei Starovoitov EMIT3_off32(0x49, 0xC7, 0xC3, imm32); 54162258278SAlexei Starovoitov 542e430f34eSAlexei Starovoitov /* mov rax, dst_reg */ 543e430f34eSAlexei Starovoitov EMIT_mov(BPF_REG_0, dst_reg); 54462258278SAlexei Starovoitov 54562258278SAlexei Starovoitov /* xor edx, edx 54662258278SAlexei Starovoitov * equivalent to 'xor rdx, rdx', but one byte less 54762258278SAlexei Starovoitov */ 54862258278SAlexei Starovoitov EMIT2(0x31, 0xd2); 54962258278SAlexei Starovoitov 55062258278SAlexei Starovoitov if (BPF_SRC(insn->code) == BPF_X) { 551e430f34eSAlexei Starovoitov /* if (src_reg == 0) return 0 */ 55262258278SAlexei Starovoitov 55362258278SAlexei Starovoitov /* cmp r11, 0 */ 55462258278SAlexei Starovoitov EMIT4(0x49, 0x83, 0xFB, 0x00); 55562258278SAlexei Starovoitov 55662258278SAlexei Starovoitov /* jne .+9 (skip over pop, pop, xor and jmp) */ 55762258278SAlexei Starovoitov EMIT2(X86_JNE, 1 + 1 + 2 + 5); 55862258278SAlexei Starovoitov EMIT1(0x5A); /* pop rdx */ 55962258278SAlexei Starovoitov EMIT1(0x58); /* pop rax */ 56062258278SAlexei Starovoitov EMIT2(0x31, 0xc0); /* xor eax, eax */ 56162258278SAlexei Starovoitov 56262258278SAlexei Starovoitov /* jmp cleanup_addr 56362258278SAlexei Starovoitov * addrs[i] - 11, because there are 11 bytes 56462258278SAlexei Starovoitov * after this insn: div, mov, pop, pop, mov 56562258278SAlexei Starovoitov */ 56662258278SAlexei Starovoitov jmp_offset = ctx->cleanup_addr - (addrs[i] - 11); 56762258278SAlexei Starovoitov EMIT1_off32(0xE9, jmp_offset); 56862258278SAlexei Starovoitov } 56962258278SAlexei Starovoitov 57062258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 57162258278SAlexei Starovoitov /* div r11 */ 57262258278SAlexei Starovoitov EMIT3(0x49, 0xF7, 0xF3); 57362258278SAlexei Starovoitov else 57462258278SAlexei Starovoitov /* div r11d */ 57562258278SAlexei Starovoitov EMIT3(0x41, 0xF7, 0xF3); 57662258278SAlexei Starovoitov 57762258278SAlexei Starovoitov if (BPF_OP(insn->code) == BPF_MOD) 57862258278SAlexei Starovoitov /* mov r11, rdx */ 57962258278SAlexei Starovoitov EMIT3(0x49, 0x89, 0xD3); 58062258278SAlexei Starovoitov else 58162258278SAlexei Starovoitov /* mov r11, rax */ 58262258278SAlexei Starovoitov EMIT3(0x49, 0x89, 0xC3); 58362258278SAlexei Starovoitov 58462258278SAlexei Starovoitov EMIT1(0x5A); /* pop rdx */ 58562258278SAlexei Starovoitov EMIT1(0x58); /* pop rax */ 58662258278SAlexei Starovoitov 587e430f34eSAlexei Starovoitov /* mov dst_reg, r11 */ 588e430f34eSAlexei Starovoitov EMIT_mov(dst_reg, AUX_REG); 58962258278SAlexei Starovoitov break; 59062258278SAlexei Starovoitov 59162258278SAlexei Starovoitov case BPF_ALU | BPF_MUL | BPF_K: 59262258278SAlexei Starovoitov case BPF_ALU | BPF_MUL | BPF_X: 59362258278SAlexei Starovoitov case BPF_ALU64 | BPF_MUL | BPF_K: 59462258278SAlexei Starovoitov case BPF_ALU64 | BPF_MUL | BPF_X: 59562258278SAlexei Starovoitov EMIT1(0x50); /* push rax */ 59662258278SAlexei Starovoitov EMIT1(0x52); /* push rdx */ 59762258278SAlexei Starovoitov 598e430f34eSAlexei Starovoitov /* mov r11, dst_reg */ 599e430f34eSAlexei Starovoitov EMIT_mov(AUX_REG, dst_reg); 60062258278SAlexei Starovoitov 60162258278SAlexei Starovoitov if (BPF_SRC(insn->code) == BPF_X) 602e430f34eSAlexei Starovoitov /* mov rax, src_reg */ 603e430f34eSAlexei Starovoitov EMIT_mov(BPF_REG_0, src_reg); 60462258278SAlexei Starovoitov else 605e430f34eSAlexei Starovoitov /* mov rax, imm32 */ 606e430f34eSAlexei Starovoitov EMIT3_off32(0x48, 0xC7, 0xC0, imm32); 60762258278SAlexei Starovoitov 60862258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 60962258278SAlexei Starovoitov EMIT1(add_1mod(0x48, AUX_REG)); 61062258278SAlexei Starovoitov else if (is_ereg(AUX_REG)) 61162258278SAlexei Starovoitov EMIT1(add_1mod(0x40, AUX_REG)); 61262258278SAlexei Starovoitov /* mul(q) r11 */ 61362258278SAlexei Starovoitov EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); 61462258278SAlexei Starovoitov 61562258278SAlexei Starovoitov /* mov r11, rax */ 61662258278SAlexei Starovoitov EMIT_mov(AUX_REG, BPF_REG_0); 61762258278SAlexei Starovoitov 61862258278SAlexei Starovoitov EMIT1(0x5A); /* pop rdx */ 61962258278SAlexei Starovoitov EMIT1(0x58); /* pop rax */ 62062258278SAlexei Starovoitov 621e430f34eSAlexei Starovoitov /* mov dst_reg, r11 */ 622e430f34eSAlexei Starovoitov EMIT_mov(dst_reg, AUX_REG); 62362258278SAlexei Starovoitov break; 62462258278SAlexei Starovoitov 62562258278SAlexei Starovoitov /* shifts */ 62662258278SAlexei Starovoitov case BPF_ALU | BPF_LSH | BPF_K: 62762258278SAlexei Starovoitov case BPF_ALU | BPF_RSH | BPF_K: 62862258278SAlexei Starovoitov case BPF_ALU | BPF_ARSH | BPF_K: 62962258278SAlexei Starovoitov case BPF_ALU64 | BPF_LSH | BPF_K: 63062258278SAlexei Starovoitov case BPF_ALU64 | BPF_RSH | BPF_K: 63162258278SAlexei Starovoitov case BPF_ALU64 | BPF_ARSH | BPF_K: 63262258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 633e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 634e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg)) 635e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 63662258278SAlexei Starovoitov 63762258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 63862258278SAlexei Starovoitov case BPF_LSH: b3 = 0xE0; break; 63962258278SAlexei Starovoitov case BPF_RSH: b3 = 0xE8; break; 64062258278SAlexei Starovoitov case BPF_ARSH: b3 = 0xF8; break; 64162258278SAlexei Starovoitov } 642e430f34eSAlexei Starovoitov EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); 64362258278SAlexei Starovoitov break; 64462258278SAlexei Starovoitov 64572b603eeSAlexei Starovoitov case BPF_ALU | BPF_LSH | BPF_X: 64672b603eeSAlexei Starovoitov case BPF_ALU | BPF_RSH | BPF_X: 64772b603eeSAlexei Starovoitov case BPF_ALU | BPF_ARSH | BPF_X: 64872b603eeSAlexei Starovoitov case BPF_ALU64 | BPF_LSH | BPF_X: 64972b603eeSAlexei Starovoitov case BPF_ALU64 | BPF_RSH | BPF_X: 65072b603eeSAlexei Starovoitov case BPF_ALU64 | BPF_ARSH | BPF_X: 65172b603eeSAlexei Starovoitov 65272b603eeSAlexei Starovoitov /* check for bad case when dst_reg == rcx */ 65372b603eeSAlexei Starovoitov if (dst_reg == BPF_REG_4) { 65472b603eeSAlexei Starovoitov /* mov r11, dst_reg */ 65572b603eeSAlexei Starovoitov EMIT_mov(AUX_REG, dst_reg); 65672b603eeSAlexei Starovoitov dst_reg = AUX_REG; 65772b603eeSAlexei Starovoitov } 65872b603eeSAlexei Starovoitov 65972b603eeSAlexei Starovoitov if (src_reg != BPF_REG_4) { /* common case */ 66072b603eeSAlexei Starovoitov EMIT1(0x51); /* push rcx */ 66172b603eeSAlexei Starovoitov 66272b603eeSAlexei Starovoitov /* mov rcx, src_reg */ 66372b603eeSAlexei Starovoitov EMIT_mov(BPF_REG_4, src_reg); 66472b603eeSAlexei Starovoitov } 66572b603eeSAlexei Starovoitov 66672b603eeSAlexei Starovoitov /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ 66772b603eeSAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 66872b603eeSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 66972b603eeSAlexei Starovoitov else if (is_ereg(dst_reg)) 67072b603eeSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 67172b603eeSAlexei Starovoitov 67272b603eeSAlexei Starovoitov switch (BPF_OP(insn->code)) { 67372b603eeSAlexei Starovoitov case BPF_LSH: b3 = 0xE0; break; 67472b603eeSAlexei Starovoitov case BPF_RSH: b3 = 0xE8; break; 67572b603eeSAlexei Starovoitov case BPF_ARSH: b3 = 0xF8; break; 67672b603eeSAlexei Starovoitov } 67772b603eeSAlexei Starovoitov EMIT2(0xD3, add_1reg(b3, dst_reg)); 67872b603eeSAlexei Starovoitov 67972b603eeSAlexei Starovoitov if (src_reg != BPF_REG_4) 68072b603eeSAlexei Starovoitov EMIT1(0x59); /* pop rcx */ 68172b603eeSAlexei Starovoitov 68272b603eeSAlexei Starovoitov if (insn->dst_reg == BPF_REG_4) 68372b603eeSAlexei Starovoitov /* mov dst_reg, r11 */ 68472b603eeSAlexei Starovoitov EMIT_mov(insn->dst_reg, AUX_REG); 68572b603eeSAlexei Starovoitov break; 68672b603eeSAlexei Starovoitov 68762258278SAlexei Starovoitov case BPF_ALU | BPF_END | BPF_FROM_BE: 688e430f34eSAlexei Starovoitov switch (imm32) { 68962258278SAlexei Starovoitov case 16: 69062258278SAlexei Starovoitov /* emit 'ror %ax, 8' to swap lower 2 bytes */ 69162258278SAlexei Starovoitov EMIT1(0x66); 692e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 69362258278SAlexei Starovoitov EMIT1(0x41); 694e430f34eSAlexei Starovoitov EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); 695343f845bSAlexei Starovoitov 696343f845bSAlexei Starovoitov /* emit 'movzwl eax, ax' */ 697343f845bSAlexei Starovoitov if (is_ereg(dst_reg)) 698343f845bSAlexei Starovoitov EMIT3(0x45, 0x0F, 0xB7); 699343f845bSAlexei Starovoitov else 700343f845bSAlexei Starovoitov EMIT2(0x0F, 0xB7); 701343f845bSAlexei Starovoitov EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); 70262258278SAlexei Starovoitov break; 70362258278SAlexei Starovoitov case 32: 70462258278SAlexei Starovoitov /* emit 'bswap eax' to swap lower 4 bytes */ 705e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 70662258278SAlexei Starovoitov EMIT2(0x41, 0x0F); 70762258278SAlexei Starovoitov else 70862258278SAlexei Starovoitov EMIT1(0x0F); 709e430f34eSAlexei Starovoitov EMIT1(add_1reg(0xC8, dst_reg)); 71062258278SAlexei Starovoitov break; 71162258278SAlexei Starovoitov case 64: 71262258278SAlexei Starovoitov /* emit 'bswap rax' to swap 8 bytes */ 713e430f34eSAlexei Starovoitov EMIT3(add_1mod(0x48, dst_reg), 0x0F, 714e430f34eSAlexei Starovoitov add_1reg(0xC8, dst_reg)); 71562258278SAlexei Starovoitov break; 71662258278SAlexei Starovoitov } 71762258278SAlexei Starovoitov break; 71862258278SAlexei Starovoitov 71962258278SAlexei Starovoitov case BPF_ALU | BPF_END | BPF_FROM_LE: 720343f845bSAlexei Starovoitov switch (imm32) { 721343f845bSAlexei Starovoitov case 16: 722343f845bSAlexei Starovoitov /* emit 'movzwl eax, ax' to zero extend 16-bit 723343f845bSAlexei Starovoitov * into 64 bit 724343f845bSAlexei Starovoitov */ 725343f845bSAlexei Starovoitov if (is_ereg(dst_reg)) 726343f845bSAlexei Starovoitov EMIT3(0x45, 0x0F, 0xB7); 727343f845bSAlexei Starovoitov else 728343f845bSAlexei Starovoitov EMIT2(0x0F, 0xB7); 729343f845bSAlexei Starovoitov EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); 730343f845bSAlexei Starovoitov break; 731343f845bSAlexei Starovoitov case 32: 732343f845bSAlexei Starovoitov /* emit 'mov eax, eax' to clear upper 32-bits */ 733343f845bSAlexei Starovoitov if (is_ereg(dst_reg)) 734343f845bSAlexei Starovoitov EMIT1(0x45); 735343f845bSAlexei Starovoitov EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); 736343f845bSAlexei Starovoitov break; 737343f845bSAlexei Starovoitov case 64: 738343f845bSAlexei Starovoitov /* nop */ 739343f845bSAlexei Starovoitov break; 740343f845bSAlexei Starovoitov } 74162258278SAlexei Starovoitov break; 74262258278SAlexei Starovoitov 743e430f34eSAlexei Starovoitov /* ST: *(u8*)(dst_reg + off) = imm */ 74462258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_B: 745e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 74662258278SAlexei Starovoitov EMIT2(0x41, 0xC6); 74762258278SAlexei Starovoitov else 74862258278SAlexei Starovoitov EMIT1(0xC6); 74962258278SAlexei Starovoitov goto st; 75062258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_H: 751e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 75262258278SAlexei Starovoitov EMIT3(0x66, 0x41, 0xC7); 75362258278SAlexei Starovoitov else 75462258278SAlexei Starovoitov EMIT2(0x66, 0xC7); 75562258278SAlexei Starovoitov goto st; 75662258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_W: 757e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 75862258278SAlexei Starovoitov EMIT2(0x41, 0xC7); 75962258278SAlexei Starovoitov else 76062258278SAlexei Starovoitov EMIT1(0xC7); 76162258278SAlexei Starovoitov goto st; 76262258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_DW: 763e430f34eSAlexei Starovoitov EMIT2(add_1mod(0x48, dst_reg), 0xC7); 76462258278SAlexei Starovoitov 76562258278SAlexei Starovoitov st: if (is_imm8(insn->off)) 766e430f34eSAlexei Starovoitov EMIT2(add_1reg(0x40, dst_reg), insn->off); 76762258278SAlexei Starovoitov else 768e430f34eSAlexei Starovoitov EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); 76962258278SAlexei Starovoitov 770e430f34eSAlexei Starovoitov EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); 77162258278SAlexei Starovoitov break; 77262258278SAlexei Starovoitov 773e430f34eSAlexei Starovoitov /* STX: *(u8*)(dst_reg + off) = src_reg */ 77462258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_B: 77562258278SAlexei Starovoitov /* emit 'mov byte ptr [rax + off], al' */ 776e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg) || 77762258278SAlexei Starovoitov /* have to add extra byte for x86 SIL, DIL regs */ 778e430f34eSAlexei Starovoitov src_reg == BPF_REG_1 || src_reg == BPF_REG_2) 779e430f34eSAlexei Starovoitov EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); 78062258278SAlexei Starovoitov else 78162258278SAlexei Starovoitov EMIT1(0x88); 78262258278SAlexei Starovoitov goto stx; 78362258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_H: 784e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 785e430f34eSAlexei Starovoitov EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); 78662258278SAlexei Starovoitov else 78762258278SAlexei Starovoitov EMIT2(0x66, 0x89); 78862258278SAlexei Starovoitov goto stx; 78962258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_W: 790e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 791e430f34eSAlexei Starovoitov EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); 79262258278SAlexei Starovoitov else 79362258278SAlexei Starovoitov EMIT1(0x89); 79462258278SAlexei Starovoitov goto stx; 79562258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_DW: 796e430f34eSAlexei Starovoitov EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); 79762258278SAlexei Starovoitov stx: if (is_imm8(insn->off)) 798e430f34eSAlexei Starovoitov EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); 79962258278SAlexei Starovoitov else 800e430f34eSAlexei Starovoitov EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), 80162258278SAlexei Starovoitov insn->off); 80262258278SAlexei Starovoitov break; 80362258278SAlexei Starovoitov 804e430f34eSAlexei Starovoitov /* LDX: dst_reg = *(u8*)(src_reg + off) */ 80562258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_B: 80662258278SAlexei Starovoitov /* emit 'movzx rax, byte ptr [rax + off]' */ 807e430f34eSAlexei Starovoitov EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); 80862258278SAlexei Starovoitov goto ldx; 80962258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_H: 81062258278SAlexei Starovoitov /* emit 'movzx rax, word ptr [rax + off]' */ 811e430f34eSAlexei Starovoitov EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); 81262258278SAlexei Starovoitov goto ldx; 81362258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_W: 81462258278SAlexei Starovoitov /* emit 'mov eax, dword ptr [rax+0x14]' */ 815e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 816e430f34eSAlexei Starovoitov EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); 81762258278SAlexei Starovoitov else 81862258278SAlexei Starovoitov EMIT1(0x8B); 81962258278SAlexei Starovoitov goto ldx; 82062258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_DW: 82162258278SAlexei Starovoitov /* emit 'mov rax, qword ptr [rax+0x14]' */ 822e430f34eSAlexei Starovoitov EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); 82362258278SAlexei Starovoitov ldx: /* if insn->off == 0 we can save one extra byte, but 82462258278SAlexei Starovoitov * special case of x86 r13 which always needs an offset 82562258278SAlexei Starovoitov * is not worth the hassle 82662258278SAlexei Starovoitov */ 82762258278SAlexei Starovoitov if (is_imm8(insn->off)) 828e430f34eSAlexei Starovoitov EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off); 82962258278SAlexei Starovoitov else 830e430f34eSAlexei Starovoitov EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), 83162258278SAlexei Starovoitov insn->off); 83262258278SAlexei Starovoitov break; 83362258278SAlexei Starovoitov 834e430f34eSAlexei Starovoitov /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ 83562258278SAlexei Starovoitov case BPF_STX | BPF_XADD | BPF_W: 83662258278SAlexei Starovoitov /* emit 'lock add dword ptr [rax + off], eax' */ 837e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 838e430f34eSAlexei Starovoitov EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); 83962258278SAlexei Starovoitov else 84062258278SAlexei Starovoitov EMIT2(0xF0, 0x01); 84162258278SAlexei Starovoitov goto xadd; 84262258278SAlexei Starovoitov case BPF_STX | BPF_XADD | BPF_DW: 843e430f34eSAlexei Starovoitov EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); 84462258278SAlexei Starovoitov xadd: if (is_imm8(insn->off)) 845e430f34eSAlexei Starovoitov EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); 84662258278SAlexei Starovoitov else 847e430f34eSAlexei Starovoitov EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), 84862258278SAlexei Starovoitov insn->off); 84962258278SAlexei Starovoitov break; 85062258278SAlexei Starovoitov 85162258278SAlexei Starovoitov /* call */ 85262258278SAlexei Starovoitov case BPF_JMP | BPF_CALL: 853e430f34eSAlexei Starovoitov func = (u8 *) __bpf_call_base + imm32; 85462258278SAlexei Starovoitov jmp_offset = func - (image + addrs[i]); 855e0ee9c12SAlexei Starovoitov if (seen_ld_abs) { 85617bedab2SMartin KaFai Lau reload_skb_data = bpf_helper_changes_pkt_data(func); 8574e10df9aSAlexei Starovoitov if (reload_skb_data) { 8584e10df9aSAlexei Starovoitov EMIT1(0x57); /* push %rdi */ 8594e10df9aSAlexei Starovoitov jmp_offset += 22; /* pop, mov, sub, mov */ 8604e10df9aSAlexei Starovoitov } else { 86162258278SAlexei Starovoitov EMIT2(0x41, 0x52); /* push %r10 */ 86262258278SAlexei Starovoitov EMIT2(0x41, 0x51); /* push %r9 */ 86362258278SAlexei Starovoitov /* need to adjust jmp offset, since 86462258278SAlexei Starovoitov * pop %r9, pop %r10 take 4 bytes after call insn 86562258278SAlexei Starovoitov */ 86662258278SAlexei Starovoitov jmp_offset += 4; 86762258278SAlexei Starovoitov } 8684e10df9aSAlexei Starovoitov } 869e430f34eSAlexei Starovoitov if (!imm32 || !is_simm32(jmp_offset)) { 87062258278SAlexei Starovoitov pr_err("unsupported bpf func %d addr %p image %p\n", 871e430f34eSAlexei Starovoitov imm32, func, image); 872f3c2af7bSAlexei Starovoitov return -EINVAL; 87362258278SAlexei Starovoitov } 87462258278SAlexei Starovoitov EMIT1_off32(0xE8, jmp_offset); 875e0ee9c12SAlexei Starovoitov if (seen_ld_abs) { 8764e10df9aSAlexei Starovoitov if (reload_skb_data) { 8774e10df9aSAlexei Starovoitov EMIT1(0x5F); /* pop %rdi */ 8784e10df9aSAlexei Starovoitov emit_load_skb_data_hlen(&prog); 8794e10df9aSAlexei Starovoitov } else { 88062258278SAlexei Starovoitov EMIT2(0x41, 0x59); /* pop %r9 */ 88162258278SAlexei Starovoitov EMIT2(0x41, 0x5A); /* pop %r10 */ 88262258278SAlexei Starovoitov } 8834e10df9aSAlexei Starovoitov } 88462258278SAlexei Starovoitov break; 88562258278SAlexei Starovoitov 886b52f00e6SAlexei Starovoitov case BPF_JMP | BPF_CALL | BPF_X: 887b52f00e6SAlexei Starovoitov emit_bpf_tail_call(&prog); 888b52f00e6SAlexei Starovoitov break; 889b52f00e6SAlexei Starovoitov 89062258278SAlexei Starovoitov /* cond jump */ 89162258278SAlexei Starovoitov case BPF_JMP | BPF_JEQ | BPF_X: 89262258278SAlexei Starovoitov case BPF_JMP | BPF_JNE | BPF_X: 89362258278SAlexei Starovoitov case BPF_JMP | BPF_JGT | BPF_X: 89462258278SAlexei Starovoitov case BPF_JMP | BPF_JGE | BPF_X: 89562258278SAlexei Starovoitov case BPF_JMP | BPF_JSGT | BPF_X: 89662258278SAlexei Starovoitov case BPF_JMP | BPF_JSGE | BPF_X: 897e430f34eSAlexei Starovoitov /* cmp dst_reg, src_reg */ 898e430f34eSAlexei Starovoitov EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39, 899e430f34eSAlexei Starovoitov add_2reg(0xC0, dst_reg, src_reg)); 90062258278SAlexei Starovoitov goto emit_cond_jmp; 90162258278SAlexei Starovoitov 90262258278SAlexei Starovoitov case BPF_JMP | BPF_JSET | BPF_X: 903e430f34eSAlexei Starovoitov /* test dst_reg, src_reg */ 904e430f34eSAlexei Starovoitov EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x85, 905e430f34eSAlexei Starovoitov add_2reg(0xC0, dst_reg, src_reg)); 90662258278SAlexei Starovoitov goto emit_cond_jmp; 90762258278SAlexei Starovoitov 90862258278SAlexei Starovoitov case BPF_JMP | BPF_JSET | BPF_K: 909e430f34eSAlexei Starovoitov /* test dst_reg, imm32 */ 910e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 911e430f34eSAlexei Starovoitov EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); 91262258278SAlexei Starovoitov goto emit_cond_jmp; 91362258278SAlexei Starovoitov 91462258278SAlexei Starovoitov case BPF_JMP | BPF_JEQ | BPF_K: 91562258278SAlexei Starovoitov case BPF_JMP | BPF_JNE | BPF_K: 91662258278SAlexei Starovoitov case BPF_JMP | BPF_JGT | BPF_K: 91762258278SAlexei Starovoitov case BPF_JMP | BPF_JGE | BPF_K: 91862258278SAlexei Starovoitov case BPF_JMP | BPF_JSGT | BPF_K: 91962258278SAlexei Starovoitov case BPF_JMP | BPF_JSGE | BPF_K: 920e430f34eSAlexei Starovoitov /* cmp dst_reg, imm8/32 */ 921e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 92262258278SAlexei Starovoitov 923e430f34eSAlexei Starovoitov if (is_imm8(imm32)) 924e430f34eSAlexei Starovoitov EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); 92562258278SAlexei Starovoitov else 926e430f34eSAlexei Starovoitov EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); 92762258278SAlexei Starovoitov 92862258278SAlexei Starovoitov emit_cond_jmp: /* convert BPF opcode to x86 */ 92962258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 93062258278SAlexei Starovoitov case BPF_JEQ: 93162258278SAlexei Starovoitov jmp_cond = X86_JE; 93262258278SAlexei Starovoitov break; 93362258278SAlexei Starovoitov case BPF_JSET: 93462258278SAlexei Starovoitov case BPF_JNE: 93562258278SAlexei Starovoitov jmp_cond = X86_JNE; 93662258278SAlexei Starovoitov break; 93762258278SAlexei Starovoitov case BPF_JGT: 93862258278SAlexei Starovoitov /* GT is unsigned '>', JA in x86 */ 93962258278SAlexei Starovoitov jmp_cond = X86_JA; 94062258278SAlexei Starovoitov break; 94162258278SAlexei Starovoitov case BPF_JGE: 94262258278SAlexei Starovoitov /* GE is unsigned '>=', JAE in x86 */ 94362258278SAlexei Starovoitov jmp_cond = X86_JAE; 94462258278SAlexei Starovoitov break; 94562258278SAlexei Starovoitov case BPF_JSGT: 94662258278SAlexei Starovoitov /* signed '>', GT in x86 */ 94762258278SAlexei Starovoitov jmp_cond = X86_JG; 94862258278SAlexei Starovoitov break; 94962258278SAlexei Starovoitov case BPF_JSGE: 95062258278SAlexei Starovoitov /* signed '>=', GE in x86 */ 95162258278SAlexei Starovoitov jmp_cond = X86_JGE; 95262258278SAlexei Starovoitov break; 95362258278SAlexei Starovoitov default: /* to silence gcc warning */ 95462258278SAlexei Starovoitov return -EFAULT; 95562258278SAlexei Starovoitov } 95662258278SAlexei Starovoitov jmp_offset = addrs[i + insn->off] - addrs[i]; 95762258278SAlexei Starovoitov if (is_imm8(jmp_offset)) { 95862258278SAlexei Starovoitov EMIT2(jmp_cond, jmp_offset); 95962258278SAlexei Starovoitov } else if (is_simm32(jmp_offset)) { 96062258278SAlexei Starovoitov EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); 9613b58908aSEric Dumazet } else { 96262258278SAlexei Starovoitov pr_err("cond_jmp gen bug %llx\n", jmp_offset); 96362258278SAlexei Starovoitov return -EFAULT; 9643b58908aSEric Dumazet } 96562258278SAlexei Starovoitov 9663b58908aSEric Dumazet break; 96762258278SAlexei Starovoitov 96862258278SAlexei Starovoitov case BPF_JMP | BPF_JA: 96962258278SAlexei Starovoitov jmp_offset = addrs[i + insn->off] - addrs[i]; 97062258278SAlexei Starovoitov if (!jmp_offset) 97162258278SAlexei Starovoitov /* optimize out nop jumps */ 97262258278SAlexei Starovoitov break; 97362258278SAlexei Starovoitov emit_jmp: 97462258278SAlexei Starovoitov if (is_imm8(jmp_offset)) { 97562258278SAlexei Starovoitov EMIT2(0xEB, jmp_offset); 97662258278SAlexei Starovoitov } else if (is_simm32(jmp_offset)) { 97762258278SAlexei Starovoitov EMIT1_off32(0xE9, jmp_offset); 97862258278SAlexei Starovoitov } else { 97962258278SAlexei Starovoitov pr_err("jmp gen bug %llx\n", jmp_offset); 98062258278SAlexei Starovoitov return -EFAULT; 9813b58908aSEric Dumazet } 98262258278SAlexei Starovoitov break; 98362258278SAlexei Starovoitov 98462258278SAlexei Starovoitov case BPF_LD | BPF_IND | BPF_W: 98562258278SAlexei Starovoitov func = sk_load_word; 98662258278SAlexei Starovoitov goto common_load; 98762258278SAlexei Starovoitov case BPF_LD | BPF_ABS | BPF_W: 988e430f34eSAlexei Starovoitov func = CHOOSE_LOAD_FUNC(imm32, sk_load_word); 989e0ee9c12SAlexei Starovoitov common_load: 990e0ee9c12SAlexei Starovoitov ctx->seen_ld_abs = seen_ld_abs = true; 99162258278SAlexei Starovoitov jmp_offset = func - (image + addrs[i]); 99262258278SAlexei Starovoitov if (!func || !is_simm32(jmp_offset)) { 99362258278SAlexei Starovoitov pr_err("unsupported bpf func %d addr %p image %p\n", 994e430f34eSAlexei Starovoitov imm32, func, image); 99562258278SAlexei Starovoitov return -EINVAL; 99662258278SAlexei Starovoitov } 99762258278SAlexei Starovoitov if (BPF_MODE(insn->code) == BPF_ABS) { 99862258278SAlexei Starovoitov /* mov %esi, imm32 */ 999e430f34eSAlexei Starovoitov EMIT1_off32(0xBE, imm32); 100062258278SAlexei Starovoitov } else { 1001e430f34eSAlexei Starovoitov /* mov %rsi, src_reg */ 1002e430f34eSAlexei Starovoitov EMIT_mov(BPF_REG_2, src_reg); 1003e430f34eSAlexei Starovoitov if (imm32) { 1004e430f34eSAlexei Starovoitov if (is_imm8(imm32)) 100562258278SAlexei Starovoitov /* add %esi, imm8 */ 1006e430f34eSAlexei Starovoitov EMIT3(0x83, 0xC6, imm32); 100762258278SAlexei Starovoitov else 100862258278SAlexei Starovoitov /* add %esi, imm32 */ 1009e430f34eSAlexei Starovoitov EMIT2_off32(0x81, 0xC6, imm32); 101062258278SAlexei Starovoitov } 101162258278SAlexei Starovoitov } 101262258278SAlexei Starovoitov /* skb pointer is in R6 (%rbx), it will be copied into 101362258278SAlexei Starovoitov * %rdi if skb_copy_bits() call is necessary. 101462258278SAlexei Starovoitov * sk_load_* helpers also use %r10 and %r9d. 101562258278SAlexei Starovoitov * See bpf_jit.S 101662258278SAlexei Starovoitov */ 1017959a7579SDaniel Borkmann if (seen_ax_reg) 1018959a7579SDaniel Borkmann /* r10 = skb->data, mov %r10, off32(%rbx) */ 1019959a7579SDaniel Borkmann EMIT3_off32(0x4c, 0x8b, 0x93, 1020959a7579SDaniel Borkmann offsetof(struct sk_buff, data)); 102162258278SAlexei Starovoitov EMIT1_off32(0xE8, jmp_offset); /* call */ 10220a14842fSEric Dumazet break; 102362258278SAlexei Starovoitov 102462258278SAlexei Starovoitov case BPF_LD | BPF_IND | BPF_H: 102562258278SAlexei Starovoitov func = sk_load_half; 102662258278SAlexei Starovoitov goto common_load; 102762258278SAlexei Starovoitov case BPF_LD | BPF_ABS | BPF_H: 1028e430f34eSAlexei Starovoitov func = CHOOSE_LOAD_FUNC(imm32, sk_load_half); 10290a14842fSEric Dumazet goto common_load; 103062258278SAlexei Starovoitov case BPF_LD | BPF_IND | BPF_B: 103162258278SAlexei Starovoitov func = sk_load_byte; 103262258278SAlexei Starovoitov goto common_load; 103362258278SAlexei Starovoitov case BPF_LD | BPF_ABS | BPF_B: 1034e430f34eSAlexei Starovoitov func = CHOOSE_LOAD_FUNC(imm32, sk_load_byte); 10350a14842fSEric Dumazet goto common_load; 10360a14842fSEric Dumazet 103762258278SAlexei Starovoitov case BPF_JMP | BPF_EXIT: 1038769e0de6SAlexei Starovoitov if (seen_exit) { 103962258278SAlexei Starovoitov jmp_offset = ctx->cleanup_addr - addrs[i]; 104062258278SAlexei Starovoitov goto emit_jmp; 104162258278SAlexei Starovoitov } 1042769e0de6SAlexei Starovoitov seen_exit = true; 104362258278SAlexei Starovoitov /* update cleanup_addr */ 104462258278SAlexei Starovoitov ctx->cleanup_addr = proglen; 104562258278SAlexei Starovoitov /* mov rbx, qword ptr [rbp-X] */ 1046b52f00e6SAlexei Starovoitov EMIT3_off32(0x48, 0x8B, 0x9D, -STACKSIZE); 104762258278SAlexei Starovoitov /* mov r13, qword ptr [rbp-X] */ 1048b52f00e6SAlexei Starovoitov EMIT3_off32(0x4C, 0x8B, 0xAD, -STACKSIZE + 8); 104962258278SAlexei Starovoitov /* mov r14, qword ptr [rbp-X] */ 1050b52f00e6SAlexei Starovoitov EMIT3_off32(0x4C, 0x8B, 0xB5, -STACKSIZE + 16); 105162258278SAlexei Starovoitov /* mov r15, qword ptr [rbp-X] */ 1052b52f00e6SAlexei Starovoitov EMIT3_off32(0x4C, 0x8B, 0xBD, -STACKSIZE + 24); 10530a14842fSEric Dumazet 105462258278SAlexei Starovoitov EMIT1(0xC9); /* leave */ 105562258278SAlexei Starovoitov EMIT1(0xC3); /* ret */ 10560a14842fSEric Dumazet break; 10570a14842fSEric Dumazet 10580a14842fSEric Dumazet default: 105962258278SAlexei Starovoitov /* By design x64 JIT should support all BPF instructions 106062258278SAlexei Starovoitov * This error will be seen if new instruction was added 106162258278SAlexei Starovoitov * to interpreter, but not to JIT 10627ae457c1SAlexei Starovoitov * or if there is junk in bpf_prog 106362258278SAlexei Starovoitov */ 106462258278SAlexei Starovoitov pr_err("bpf_jit: unknown opcode %02x\n", insn->code); 1065f3c2af7bSAlexei Starovoitov return -EINVAL; 10660a14842fSEric Dumazet } 106762258278SAlexei Starovoitov 10680a14842fSEric Dumazet ilen = prog - temp; 1069e0ee9c12SAlexei Starovoitov if (ilen > BPF_MAX_INSN_SIZE) { 1070e0ee9c12SAlexei Starovoitov pr_err("bpf_jit_compile fatal insn size error\n"); 1071e0ee9c12SAlexei Starovoitov return -EFAULT; 1072e0ee9c12SAlexei Starovoitov } 1073e0ee9c12SAlexei Starovoitov 10740a14842fSEric Dumazet if (image) { 10750a14842fSEric Dumazet if (unlikely(proglen + ilen > oldproglen)) { 107662258278SAlexei Starovoitov pr_err("bpf_jit_compile fatal error\n"); 1077f3c2af7bSAlexei Starovoitov return -EFAULT; 10780a14842fSEric Dumazet } 10790a14842fSEric Dumazet memcpy(image + proglen, temp, ilen); 10800a14842fSEric Dumazet } 10810a14842fSEric Dumazet proglen += ilen; 10820a14842fSEric Dumazet addrs[i] = proglen; 10830a14842fSEric Dumazet prog = temp; 10840a14842fSEric Dumazet } 1085f3c2af7bSAlexei Starovoitov return proglen; 1086f3c2af7bSAlexei Starovoitov } 1087f3c2af7bSAlexei Starovoitov 10887ae457c1SAlexei Starovoitov void bpf_jit_compile(struct bpf_prog *prog) 1089f3c2af7bSAlexei Starovoitov { 109062258278SAlexei Starovoitov } 109162258278SAlexei Starovoitov 1092d1c55ab5SDaniel Borkmann struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) 109362258278SAlexei Starovoitov { 1094f3c2af7bSAlexei Starovoitov struct bpf_binary_header *header = NULL; 1095959a7579SDaniel Borkmann struct bpf_prog *tmp, *orig_prog = prog; 1096f3c2af7bSAlexei Starovoitov int proglen, oldproglen = 0; 1097f3c2af7bSAlexei Starovoitov struct jit_context ctx = {}; 1098959a7579SDaniel Borkmann bool tmp_blinded = false; 1099f3c2af7bSAlexei Starovoitov u8 *image = NULL; 1100f3c2af7bSAlexei Starovoitov int *addrs; 1101f3c2af7bSAlexei Starovoitov int pass; 1102f3c2af7bSAlexei Starovoitov int i; 1103f3c2af7bSAlexei Starovoitov 1104f3c2af7bSAlexei Starovoitov if (!bpf_jit_enable) 1105959a7579SDaniel Borkmann return orig_prog; 1106959a7579SDaniel Borkmann 1107959a7579SDaniel Borkmann tmp = bpf_jit_blind_constants(prog); 1108959a7579SDaniel Borkmann /* If blinding was requested and we failed during blinding, 1109959a7579SDaniel Borkmann * we must fall back to the interpreter. 1110959a7579SDaniel Borkmann */ 1111959a7579SDaniel Borkmann if (IS_ERR(tmp)) 1112959a7579SDaniel Borkmann return orig_prog; 1113959a7579SDaniel Borkmann if (tmp != prog) { 1114959a7579SDaniel Borkmann tmp_blinded = true; 1115959a7579SDaniel Borkmann prog = tmp; 1116959a7579SDaniel Borkmann } 1117f3c2af7bSAlexei Starovoitov 1118f3c2af7bSAlexei Starovoitov addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL); 1119959a7579SDaniel Borkmann if (!addrs) { 1120959a7579SDaniel Borkmann prog = orig_prog; 1121959a7579SDaniel Borkmann goto out; 1122959a7579SDaniel Borkmann } 1123f3c2af7bSAlexei Starovoitov 1124f3c2af7bSAlexei Starovoitov /* Before first pass, make a rough estimation of addrs[] 1125f3c2af7bSAlexei Starovoitov * each bpf instruction is translated to less than 64 bytes 1126f3c2af7bSAlexei Starovoitov */ 1127f3c2af7bSAlexei Starovoitov for (proglen = 0, i = 0; i < prog->len; i++) { 1128f3c2af7bSAlexei Starovoitov proglen += 64; 1129f3c2af7bSAlexei Starovoitov addrs[i] = proglen; 1130f3c2af7bSAlexei Starovoitov } 1131f3c2af7bSAlexei Starovoitov ctx.cleanup_addr = proglen; 1132f3c2af7bSAlexei Starovoitov 11333f7352bfSAlexei Starovoitov /* JITed image shrinks with every pass and the loop iterates 11343f7352bfSAlexei Starovoitov * until the image stops shrinking. Very large bpf programs 11353f7352bfSAlexei Starovoitov * may converge on the last pass. In such case do one more 11363f7352bfSAlexei Starovoitov * pass to emit the final image 11373f7352bfSAlexei Starovoitov */ 11383f7352bfSAlexei Starovoitov for (pass = 0; pass < 10 || image; pass++) { 1139f3c2af7bSAlexei Starovoitov proglen = do_jit(prog, addrs, image, oldproglen, &ctx); 1140f3c2af7bSAlexei Starovoitov if (proglen <= 0) { 1141f3c2af7bSAlexei Starovoitov image = NULL; 1142f3c2af7bSAlexei Starovoitov if (header) 1143738cbe72SDaniel Borkmann bpf_jit_binary_free(header); 1144959a7579SDaniel Borkmann prog = orig_prog; 1145959a7579SDaniel Borkmann goto out_addrs; 1146f3c2af7bSAlexei Starovoitov } 11470a14842fSEric Dumazet if (image) { 1148e0ee9c12SAlexei Starovoitov if (proglen != oldproglen) { 1149f3c2af7bSAlexei Starovoitov pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", 1150f3c2af7bSAlexei Starovoitov proglen, oldproglen); 1151959a7579SDaniel Borkmann prog = orig_prog; 1152959a7579SDaniel Borkmann goto out_addrs; 1153e0ee9c12SAlexei Starovoitov } 11540a14842fSEric Dumazet break; 11550a14842fSEric Dumazet } 11560a14842fSEric Dumazet if (proglen == oldproglen) { 1157738cbe72SDaniel Borkmann header = bpf_jit_binary_alloc(proglen, &image, 1158738cbe72SDaniel Borkmann 1, jit_fill_hole); 1159959a7579SDaniel Borkmann if (!header) { 1160959a7579SDaniel Borkmann prog = orig_prog; 1161959a7579SDaniel Borkmann goto out_addrs; 1162959a7579SDaniel Borkmann } 11630a14842fSEric Dumazet } 11640a14842fSEric Dumazet oldproglen = proglen; 11650a14842fSEric Dumazet } 116679617801SDaniel Borkmann 11670a14842fSEric Dumazet if (bpf_jit_enable > 1) 1168485d6511SDaniel Borkmann bpf_jit_dump(prog->len, proglen, pass + 1, image); 11690a14842fSEric Dumazet 11700a14842fSEric Dumazet if (image) { 1171314beb9bSEric Dumazet bpf_flush_icache(header, image + proglen); 1172314beb9bSEric Dumazet set_memory_ro((unsigned long)header, header->pages); 1173f3c2af7bSAlexei Starovoitov prog->bpf_func = (void *)image; 1174a91263d5SDaniel Borkmann prog->jited = 1; 11750a14842fSEric Dumazet } 1176959a7579SDaniel Borkmann 1177959a7579SDaniel Borkmann out_addrs: 11780a14842fSEric Dumazet kfree(addrs); 1179959a7579SDaniel Borkmann out: 1180959a7579SDaniel Borkmann if (tmp_blinded) 1181959a7579SDaniel Borkmann bpf_jit_prog_release_other(prog, prog == orig_prog ? 1182959a7579SDaniel Borkmann tmp : orig_prog); 1183d1c55ab5SDaniel Borkmann return prog; 11840a14842fSEric Dumazet } 11850a14842fSEric Dumazet 118660a3b225SDaniel Borkmann void bpf_jit_free(struct bpf_prog *fp) 11870a14842fSEric Dumazet { 1188314beb9bSEric Dumazet unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK; 1189314beb9bSEric Dumazet struct bpf_binary_header *header = (void *)addr; 1190314beb9bSEric Dumazet 119160a3b225SDaniel Borkmann if (!fp->jited) 119260a3b225SDaniel Borkmann goto free_filter; 119360a3b225SDaniel Borkmann 1194314beb9bSEric Dumazet set_memory_rw(addr, header->pages); 1195738cbe72SDaniel Borkmann bpf_jit_binary_free(header); 1196d45ed4a4SAlexei Starovoitov 119760a3b225SDaniel Borkmann free_filter: 119860a3b225SDaniel Borkmann bpf_prog_unlock_free(fp); 11990a14842fSEric Dumazet } 1200