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> 15d1163651SLaura Abbott #include <asm/set_memory.h> 16b52f00e6SAlexei Starovoitov #include <linux/bpf.h> 170a14842fSEric Dumazet 180a14842fSEric Dumazet int bpf_jit_enable __read_mostly; 190a14842fSEric Dumazet 200a14842fSEric Dumazet /* 210a14842fSEric Dumazet * assembly code in arch/x86/net/bpf_jit.S 220a14842fSEric Dumazet */ 2362258278SAlexei Starovoitov extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; 24a998d434SJan Seiffert extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[]; 2562258278SAlexei Starovoitov extern u8 sk_load_byte_positive_offset[]; 26a998d434SJan Seiffert extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[]; 2762258278SAlexei Starovoitov extern u8 sk_load_byte_negative_offset[]; 280a14842fSEric Dumazet 295cccc702SJoe Perches static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) 300a14842fSEric Dumazet { 310a14842fSEric Dumazet if (len == 1) 320a14842fSEric Dumazet *ptr = bytes; 330a14842fSEric Dumazet else if (len == 2) 340a14842fSEric Dumazet *(u16 *)ptr = bytes; 350a14842fSEric Dumazet else { 360a14842fSEric Dumazet *(u32 *)ptr = bytes; 370a14842fSEric Dumazet barrier(); 380a14842fSEric Dumazet } 390a14842fSEric Dumazet return ptr + len; 400a14842fSEric Dumazet } 410a14842fSEric Dumazet 42b52f00e6SAlexei Starovoitov #define EMIT(bytes, len) \ 43b52f00e6SAlexei Starovoitov do { prog = emit_code(prog, bytes, len); cnt += len; } while (0) 440a14842fSEric Dumazet 450a14842fSEric Dumazet #define EMIT1(b1) EMIT(b1, 1) 460a14842fSEric Dumazet #define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2) 470a14842fSEric Dumazet #define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3) 480a14842fSEric Dumazet #define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4) 4962258278SAlexei Starovoitov #define EMIT1_off32(b1, off) \ 5062258278SAlexei Starovoitov do {EMIT1(b1); EMIT(off, 4); } while (0) 5162258278SAlexei Starovoitov #define EMIT2_off32(b1, b2, off) \ 5262258278SAlexei Starovoitov do {EMIT2(b1, b2); EMIT(off, 4); } while (0) 5362258278SAlexei Starovoitov #define EMIT3_off32(b1, b2, b3, off) \ 5462258278SAlexei Starovoitov do {EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) 5562258278SAlexei Starovoitov #define EMIT4_off32(b1, b2, b3, b4, off) \ 5662258278SAlexei Starovoitov do {EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) 570a14842fSEric Dumazet 585cccc702SJoe Perches static bool is_imm8(int value) 590a14842fSEric Dumazet { 600a14842fSEric Dumazet return value <= 127 && value >= -128; 610a14842fSEric Dumazet } 620a14842fSEric Dumazet 635cccc702SJoe Perches static bool is_simm32(s64 value) 640a14842fSEric Dumazet { 6562258278SAlexei Starovoitov return value == (s64) (s32) value; 660a14842fSEric Dumazet } 670a14842fSEric Dumazet 68e430f34eSAlexei Starovoitov /* mov dst, src */ 69e430f34eSAlexei Starovoitov #define EMIT_mov(DST, SRC) \ 70e430f34eSAlexei Starovoitov do {if (DST != SRC) \ 71e430f34eSAlexei Starovoitov EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ 720a14842fSEric Dumazet } while (0) 730a14842fSEric Dumazet 7462258278SAlexei Starovoitov static int bpf_size_to_x86_bytes(int bpf_size) 7562258278SAlexei Starovoitov { 7662258278SAlexei Starovoitov if (bpf_size == BPF_W) 7762258278SAlexei Starovoitov return 4; 7862258278SAlexei Starovoitov else if (bpf_size == BPF_H) 7962258278SAlexei Starovoitov return 2; 8062258278SAlexei Starovoitov else if (bpf_size == BPF_B) 8162258278SAlexei Starovoitov return 1; 8262258278SAlexei Starovoitov else if (bpf_size == BPF_DW) 8362258278SAlexei Starovoitov return 4; /* imm32 */ 8462258278SAlexei Starovoitov else 8562258278SAlexei Starovoitov return 0; 8662258278SAlexei Starovoitov } 8762258278SAlexei Starovoitov 880a14842fSEric Dumazet /* list of x86 cond jumps opcodes (. + s8) 890a14842fSEric Dumazet * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32) 900a14842fSEric Dumazet */ 910a14842fSEric Dumazet #define X86_JB 0x72 920a14842fSEric Dumazet #define X86_JAE 0x73 930a14842fSEric Dumazet #define X86_JE 0x74 940a14842fSEric Dumazet #define X86_JNE 0x75 950a14842fSEric Dumazet #define X86_JBE 0x76 960a14842fSEric Dumazet #define X86_JA 0x77 9752afc51eSDaniel Borkmann #define X86_JL 0x7C 9862258278SAlexei Starovoitov #define X86_JGE 0x7D 9952afc51eSDaniel Borkmann #define X86_JLE 0x7E 10062258278SAlexei Starovoitov #define X86_JG 0x7F 1010a14842fSEric Dumazet 1025cccc702SJoe Perches static void bpf_flush_icache(void *start, void *end) 1030a14842fSEric Dumazet { 1040a14842fSEric Dumazet mm_segment_t old_fs = get_fs(); 1050a14842fSEric Dumazet 1060a14842fSEric Dumazet set_fs(KERNEL_DS); 1070a14842fSEric Dumazet smp_wmb(); 1080a14842fSEric Dumazet flush_icache_range((unsigned long)start, (unsigned long)end); 1090a14842fSEric Dumazet set_fs(old_fs); 1100a14842fSEric Dumazet } 1110a14842fSEric Dumazet 112a998d434SJan Seiffert #define CHOOSE_LOAD_FUNC(K, func) \ 113a998d434SJan Seiffert ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) 1140a14842fSEric Dumazet 11562258278SAlexei Starovoitov /* pick a register outside of BPF range for JIT internal work */ 116959a7579SDaniel Borkmann #define AUX_REG (MAX_BPF_JIT_REG + 1) 11762258278SAlexei Starovoitov 118959a7579SDaniel Borkmann /* The following table maps BPF registers to x64 registers. 119959a7579SDaniel Borkmann * 120959a7579SDaniel Borkmann * x64 register r12 is unused, since if used as base address 121959a7579SDaniel Borkmann * register in load/store instructions, it always needs an 122959a7579SDaniel Borkmann * extra byte of encoding and is callee saved. 123959a7579SDaniel Borkmann * 124959a7579SDaniel Borkmann * r9 caches skb->len - skb->data_len 125959a7579SDaniel Borkmann * r10 caches skb->data, and used for blinding (if enabled) 12662258278SAlexei Starovoitov */ 12762258278SAlexei Starovoitov static const int reg2hex[] = { 12862258278SAlexei Starovoitov [BPF_REG_0] = 0, /* rax */ 12962258278SAlexei Starovoitov [BPF_REG_1] = 7, /* rdi */ 13062258278SAlexei Starovoitov [BPF_REG_2] = 6, /* rsi */ 13162258278SAlexei Starovoitov [BPF_REG_3] = 2, /* rdx */ 13262258278SAlexei Starovoitov [BPF_REG_4] = 1, /* rcx */ 13362258278SAlexei Starovoitov [BPF_REG_5] = 0, /* r8 */ 13462258278SAlexei Starovoitov [BPF_REG_6] = 3, /* rbx callee saved */ 13562258278SAlexei Starovoitov [BPF_REG_7] = 5, /* r13 callee saved */ 13662258278SAlexei Starovoitov [BPF_REG_8] = 6, /* r14 callee saved */ 13762258278SAlexei Starovoitov [BPF_REG_9] = 7, /* r15 callee saved */ 13862258278SAlexei Starovoitov [BPF_REG_FP] = 5, /* rbp readonly */ 139959a7579SDaniel Borkmann [BPF_REG_AX] = 2, /* r10 temp register */ 14062258278SAlexei Starovoitov [AUX_REG] = 3, /* r11 temp register */ 14162258278SAlexei Starovoitov }; 14262258278SAlexei Starovoitov 14362258278SAlexei Starovoitov /* is_ereg() == true if BPF register 'reg' maps to x64 r8..r15 14462258278SAlexei Starovoitov * which need extra byte of encoding. 14562258278SAlexei Starovoitov * rax,rcx,...,rbp have simpler encoding 14662258278SAlexei Starovoitov */ 1475cccc702SJoe Perches static bool is_ereg(u32 reg) 14862258278SAlexei Starovoitov { 149d148134bSJoe Perches return (1 << reg) & (BIT(BPF_REG_5) | 150d148134bSJoe Perches BIT(AUX_REG) | 151d148134bSJoe Perches BIT(BPF_REG_7) | 152d148134bSJoe Perches BIT(BPF_REG_8) | 153959a7579SDaniel Borkmann BIT(BPF_REG_9) | 154959a7579SDaniel Borkmann BIT(BPF_REG_AX)); 15562258278SAlexei Starovoitov } 15662258278SAlexei Starovoitov 15762258278SAlexei Starovoitov /* add modifiers if 'reg' maps to x64 registers r8..r15 */ 1585cccc702SJoe Perches static u8 add_1mod(u8 byte, u32 reg) 15962258278SAlexei Starovoitov { 16062258278SAlexei Starovoitov if (is_ereg(reg)) 16162258278SAlexei Starovoitov byte |= 1; 16262258278SAlexei Starovoitov return byte; 16362258278SAlexei Starovoitov } 16462258278SAlexei Starovoitov 1655cccc702SJoe Perches static u8 add_2mod(u8 byte, u32 r1, u32 r2) 16662258278SAlexei Starovoitov { 16762258278SAlexei Starovoitov if (is_ereg(r1)) 16862258278SAlexei Starovoitov byte |= 1; 16962258278SAlexei Starovoitov if (is_ereg(r2)) 17062258278SAlexei Starovoitov byte |= 4; 17162258278SAlexei Starovoitov return byte; 17262258278SAlexei Starovoitov } 17362258278SAlexei Starovoitov 174e430f34eSAlexei Starovoitov /* encode 'dst_reg' register into x64 opcode 'byte' */ 1755cccc702SJoe Perches static u8 add_1reg(u8 byte, u32 dst_reg) 17662258278SAlexei Starovoitov { 177e430f34eSAlexei Starovoitov return byte + reg2hex[dst_reg]; 17862258278SAlexei Starovoitov } 17962258278SAlexei Starovoitov 180e430f34eSAlexei Starovoitov /* encode 'dst_reg' and 'src_reg' registers into x64 opcode 'byte' */ 1815cccc702SJoe Perches static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) 18262258278SAlexei Starovoitov { 183e430f34eSAlexei Starovoitov return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); 18462258278SAlexei Starovoitov } 18562258278SAlexei Starovoitov 186738cbe72SDaniel Borkmann static void jit_fill_hole(void *area, unsigned int size) 187738cbe72SDaniel Borkmann { 188738cbe72SDaniel Borkmann /* fill whole space with int3 instructions */ 189738cbe72SDaniel Borkmann memset(area, 0xcc, size); 190738cbe72SDaniel Borkmann } 191738cbe72SDaniel Borkmann 192f3c2af7bSAlexei Starovoitov struct jit_context { 193769e0de6SAlexei Starovoitov int cleanup_addr; /* epilogue code offset */ 19462258278SAlexei Starovoitov bool seen_ld_abs; 195959a7579SDaniel Borkmann bool seen_ax_reg; 196f3c2af7bSAlexei Starovoitov }; 197f3c2af7bSAlexei Starovoitov 198e0ee9c12SAlexei Starovoitov /* maximum number of bytes emitted while JITing one eBPF insn */ 199e0ee9c12SAlexei Starovoitov #define BPF_MAX_INSN_SIZE 128 200e0ee9c12SAlexei Starovoitov #define BPF_INSN_SAFETY 64 201e0ee9c12SAlexei Starovoitov 202177366bfSAlexei Starovoitov #define AUX_STACK_SPACE \ 203177366bfSAlexei Starovoitov (32 /* space for rbx, r13, r14, r15 */ + \ 204b52f00e6SAlexei Starovoitov 8 /* space for skb_copy_bits() buffer */) 205b52f00e6SAlexei Starovoitov 206177366bfSAlexei Starovoitov #define PROLOGUE_SIZE 37 207b52f00e6SAlexei Starovoitov 208b52f00e6SAlexei Starovoitov /* emit x64 prologue code for BPF program and check it's size. 209b52f00e6SAlexei Starovoitov * bpf_tail_call helper will skip it while jumping into another program 210b52f00e6SAlexei Starovoitov */ 2112960ae48SAlexei Starovoitov static void emit_prologue(u8 **pprog, u32 stack_depth) 2120a14842fSEric Dumazet { 213b52f00e6SAlexei Starovoitov u8 *prog = *pprog; 214b52f00e6SAlexei Starovoitov int cnt = 0; 2150a14842fSEric Dumazet 21662258278SAlexei Starovoitov EMIT1(0x55); /* push rbp */ 21762258278SAlexei Starovoitov EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */ 2180a14842fSEric Dumazet 2192960ae48SAlexei Starovoitov /* sub rsp, rounded_stack_depth + AUX_STACK_SPACE */ 2202960ae48SAlexei Starovoitov EMIT3_off32(0x48, 0x81, 0xEC, 2212960ae48SAlexei Starovoitov round_up(stack_depth, 8) + AUX_STACK_SPACE); 222177366bfSAlexei Starovoitov 223177366bfSAlexei Starovoitov /* sub rbp, AUX_STACK_SPACE */ 224177366bfSAlexei Starovoitov EMIT4(0x48, 0x83, 0xED, AUX_STACK_SPACE); 2250a14842fSEric Dumazet 22662258278SAlexei Starovoitov /* all classic BPF filters use R6(rbx) save it */ 22762258278SAlexei Starovoitov 228177366bfSAlexei Starovoitov /* mov qword ptr [rbp+0],rbx */ 229177366bfSAlexei Starovoitov EMIT4(0x48, 0x89, 0x5D, 0); 23062258278SAlexei Starovoitov 2318fb575caSAlexei Starovoitov /* bpf_convert_filter() maps classic BPF register X to R7 and uses R8 23262258278SAlexei Starovoitov * as temporary, so all tcpdump filters need to spill/fill R7(r13) and 23362258278SAlexei Starovoitov * R8(r14). R9(r15) spill could be made conditional, but there is only 23462258278SAlexei Starovoitov * one 'bpf_error' return path out of helper functions inside bpf_jit.S 23562258278SAlexei Starovoitov * The overhead of extra spill is negligible for any filter other 23662258278SAlexei Starovoitov * than synthetic ones. Therefore not worth adding complexity. 2370a14842fSEric Dumazet */ 23862258278SAlexei Starovoitov 239177366bfSAlexei Starovoitov /* mov qword ptr [rbp+8],r13 */ 240177366bfSAlexei Starovoitov EMIT4(0x4C, 0x89, 0x6D, 8); 241177366bfSAlexei Starovoitov /* mov qword ptr [rbp+16],r14 */ 242177366bfSAlexei Starovoitov EMIT4(0x4C, 0x89, 0x75, 16); 243177366bfSAlexei Starovoitov /* mov qword ptr [rbp+24],r15 */ 244177366bfSAlexei Starovoitov EMIT4(0x4C, 0x89, 0x7D, 24); 24562258278SAlexei Starovoitov 2468b614aebSDaniel Borkmann /* Clear the tail call counter (tail_call_cnt): for eBPF tail calls 2478b614aebSDaniel Borkmann * we need to reset the counter to 0. It's done in two instructions, 2488b614aebSDaniel Borkmann * resetting rax register to 0 (xor on eax gets 0 extended), and 2498b614aebSDaniel Borkmann * moving it to the counter location. 2508b614aebSDaniel Borkmann */ 25162258278SAlexei Starovoitov 2528b614aebSDaniel Borkmann /* xor eax, eax */ 2538b614aebSDaniel Borkmann EMIT2(0x31, 0xc0); 254177366bfSAlexei Starovoitov /* mov qword ptr [rbp+32], rax */ 255177366bfSAlexei Starovoitov EMIT4(0x48, 0x89, 0x45, 32); 256b52f00e6SAlexei Starovoitov 257b52f00e6SAlexei Starovoitov BUILD_BUG_ON(cnt != PROLOGUE_SIZE); 258b52f00e6SAlexei Starovoitov *pprog = prog; 259b52f00e6SAlexei Starovoitov } 260b52f00e6SAlexei Starovoitov 261b52f00e6SAlexei Starovoitov /* generate the following code: 262b52f00e6SAlexei Starovoitov * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... 263b52f00e6SAlexei Starovoitov * if (index >= array->map.max_entries) 264b52f00e6SAlexei Starovoitov * goto out; 265b52f00e6SAlexei Starovoitov * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) 266b52f00e6SAlexei Starovoitov * goto out; 2672a36f0b9SWang Nan * prog = array->ptrs[index]; 268b52f00e6SAlexei Starovoitov * if (prog == NULL) 269b52f00e6SAlexei Starovoitov * goto out; 270b52f00e6SAlexei Starovoitov * goto *(prog->bpf_func + prologue_size); 271b52f00e6SAlexei Starovoitov * out: 272b52f00e6SAlexei Starovoitov */ 273b52f00e6SAlexei Starovoitov static void emit_bpf_tail_call(u8 **pprog) 274b52f00e6SAlexei Starovoitov { 275b52f00e6SAlexei Starovoitov u8 *prog = *pprog; 276b52f00e6SAlexei Starovoitov int label1, label2, label3; 277b52f00e6SAlexei Starovoitov int cnt = 0; 278b52f00e6SAlexei Starovoitov 279b52f00e6SAlexei Starovoitov /* rdi - pointer to ctx 280b52f00e6SAlexei Starovoitov * rsi - pointer to bpf_array 281b52f00e6SAlexei Starovoitov * rdx - index in bpf_array 282b52f00e6SAlexei Starovoitov */ 283b52f00e6SAlexei Starovoitov 284b52f00e6SAlexei Starovoitov /* if (index >= array->map.max_entries) 285b52f00e6SAlexei Starovoitov * goto out; 286b52f00e6SAlexei Starovoitov */ 287b52f00e6SAlexei Starovoitov EMIT4(0x48, 0x8B, 0x46, /* mov rax, qword ptr [rsi + 16] */ 288b52f00e6SAlexei Starovoitov offsetof(struct bpf_array, map.max_entries)); 289b52f00e6SAlexei Starovoitov EMIT3(0x48, 0x39, 0xD0); /* cmp rax, rdx */ 29084ccac6eSEric Dumazet #define OFFSET1 43 /* number of bytes to jump */ 291b52f00e6SAlexei Starovoitov EMIT2(X86_JBE, OFFSET1); /* jbe out */ 292b52f00e6SAlexei Starovoitov label1 = cnt; 293b52f00e6SAlexei Starovoitov 294b52f00e6SAlexei Starovoitov /* if (tail_call_cnt > MAX_TAIL_CALL_CNT) 295b52f00e6SAlexei Starovoitov * goto out; 296b52f00e6SAlexei Starovoitov */ 297177366bfSAlexei Starovoitov EMIT2_off32(0x8B, 0x85, 36); /* mov eax, dword ptr [rbp + 36] */ 298b52f00e6SAlexei Starovoitov EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ 29984ccac6eSEric Dumazet #define OFFSET2 32 300b52f00e6SAlexei Starovoitov EMIT2(X86_JA, OFFSET2); /* ja out */ 301b52f00e6SAlexei Starovoitov label2 = cnt; 302b52f00e6SAlexei Starovoitov EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ 303177366bfSAlexei Starovoitov EMIT2_off32(0x89, 0x85, 36); /* mov dword ptr [rbp + 36], eax */ 304b52f00e6SAlexei Starovoitov 3052a36f0b9SWang Nan /* prog = array->ptrs[index]; */ 30684ccac6eSEric Dumazet EMIT4_off32(0x48, 0x8B, 0x84, 0xD6, /* mov rax, [rsi + rdx * 8 + offsetof(...)] */ 3072a36f0b9SWang Nan offsetof(struct bpf_array, ptrs)); 308b52f00e6SAlexei Starovoitov 309b52f00e6SAlexei Starovoitov /* if (prog == NULL) 310b52f00e6SAlexei Starovoitov * goto out; 311b52f00e6SAlexei Starovoitov */ 31284ccac6eSEric Dumazet EMIT3(0x48, 0x85, 0xC0); /* test rax,rax */ 313b52f00e6SAlexei Starovoitov #define OFFSET3 10 314b52f00e6SAlexei Starovoitov EMIT2(X86_JE, OFFSET3); /* je out */ 315b52f00e6SAlexei Starovoitov label3 = cnt; 316b52f00e6SAlexei Starovoitov 317b52f00e6SAlexei Starovoitov /* goto *(prog->bpf_func + prologue_size); */ 318b52f00e6SAlexei Starovoitov EMIT4(0x48, 0x8B, 0x40, /* mov rax, qword ptr [rax + 32] */ 319b52f00e6SAlexei Starovoitov offsetof(struct bpf_prog, bpf_func)); 320b52f00e6SAlexei Starovoitov EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */ 321b52f00e6SAlexei Starovoitov 322b52f00e6SAlexei Starovoitov /* now we're ready to jump into next BPF program 323b52f00e6SAlexei Starovoitov * rdi == ctx (1st arg) 324b52f00e6SAlexei Starovoitov * rax == prog->bpf_func + prologue_size 325b52f00e6SAlexei Starovoitov */ 326b52f00e6SAlexei Starovoitov EMIT2(0xFF, 0xE0); /* jmp rax */ 327b52f00e6SAlexei Starovoitov 328b52f00e6SAlexei Starovoitov /* out: */ 329b52f00e6SAlexei Starovoitov BUILD_BUG_ON(cnt - label1 != OFFSET1); 330b52f00e6SAlexei Starovoitov BUILD_BUG_ON(cnt - label2 != OFFSET2); 331b52f00e6SAlexei Starovoitov BUILD_BUG_ON(cnt - label3 != OFFSET3); 332b52f00e6SAlexei Starovoitov *pprog = prog; 333b52f00e6SAlexei Starovoitov } 334b52f00e6SAlexei Starovoitov 3354e10df9aSAlexei Starovoitov 3364e10df9aSAlexei Starovoitov static void emit_load_skb_data_hlen(u8 **pprog) 3374e10df9aSAlexei Starovoitov { 3384e10df9aSAlexei Starovoitov u8 *prog = *pprog; 3394e10df9aSAlexei Starovoitov int cnt = 0; 3404e10df9aSAlexei Starovoitov 3414e10df9aSAlexei Starovoitov /* r9d = skb->len - skb->data_len (headlen) 3424e10df9aSAlexei Starovoitov * r10 = skb->data 3434e10df9aSAlexei Starovoitov */ 3444e10df9aSAlexei Starovoitov /* mov %r9d, off32(%rdi) */ 3454e10df9aSAlexei Starovoitov EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len)); 3464e10df9aSAlexei Starovoitov 3474e10df9aSAlexei Starovoitov /* sub %r9d, off32(%rdi) */ 3484e10df9aSAlexei Starovoitov EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len)); 3494e10df9aSAlexei Starovoitov 3504e10df9aSAlexei Starovoitov /* mov %r10, off32(%rdi) */ 3514e10df9aSAlexei Starovoitov EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data)); 3524e10df9aSAlexei Starovoitov *pprog = prog; 3534e10df9aSAlexei Starovoitov } 3544e10df9aSAlexei Starovoitov 355b52f00e6SAlexei Starovoitov static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, 356b52f00e6SAlexei Starovoitov int oldproglen, struct jit_context *ctx) 357b52f00e6SAlexei Starovoitov { 358b52f00e6SAlexei Starovoitov struct bpf_insn *insn = bpf_prog->insnsi; 359b52f00e6SAlexei Starovoitov int insn_cnt = bpf_prog->len; 360b52f00e6SAlexei Starovoitov bool seen_ld_abs = ctx->seen_ld_abs | (oldproglen == 0); 361959a7579SDaniel Borkmann bool seen_ax_reg = ctx->seen_ax_reg | (oldproglen == 0); 362b52f00e6SAlexei Starovoitov bool seen_exit = false; 363b52f00e6SAlexei Starovoitov u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; 364b52f00e6SAlexei Starovoitov int i, cnt = 0; 365b52f00e6SAlexei Starovoitov int proglen = 0; 366b52f00e6SAlexei Starovoitov u8 *prog = temp; 367b52f00e6SAlexei Starovoitov 3682960ae48SAlexei Starovoitov emit_prologue(&prog, bpf_prog->aux->stack_depth); 369b52f00e6SAlexei Starovoitov 3704e10df9aSAlexei Starovoitov if (seen_ld_abs) 3714e10df9aSAlexei Starovoitov emit_load_skb_data_hlen(&prog); 37262258278SAlexei Starovoitov 37362258278SAlexei Starovoitov for (i = 0; i < insn_cnt; i++, insn++) { 374e430f34eSAlexei Starovoitov const s32 imm32 = insn->imm; 375e430f34eSAlexei Starovoitov u32 dst_reg = insn->dst_reg; 376e430f34eSAlexei Starovoitov u32 src_reg = insn->src_reg; 37762258278SAlexei Starovoitov u8 b1 = 0, b2 = 0, b3 = 0; 37862258278SAlexei Starovoitov s64 jmp_offset; 37962258278SAlexei Starovoitov u8 jmp_cond; 3804e10df9aSAlexei Starovoitov bool reload_skb_data; 38162258278SAlexei Starovoitov int ilen; 38262258278SAlexei Starovoitov u8 *func; 38362258278SAlexei Starovoitov 384959a7579SDaniel Borkmann if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX) 385959a7579SDaniel Borkmann ctx->seen_ax_reg = seen_ax_reg = true; 386959a7579SDaniel Borkmann 38762258278SAlexei Starovoitov switch (insn->code) { 38862258278SAlexei Starovoitov /* ALU */ 38962258278SAlexei Starovoitov case BPF_ALU | BPF_ADD | BPF_X: 39062258278SAlexei Starovoitov case BPF_ALU | BPF_SUB | BPF_X: 39162258278SAlexei Starovoitov case BPF_ALU | BPF_AND | BPF_X: 39262258278SAlexei Starovoitov case BPF_ALU | BPF_OR | BPF_X: 39362258278SAlexei Starovoitov case BPF_ALU | BPF_XOR | BPF_X: 39462258278SAlexei Starovoitov case BPF_ALU64 | BPF_ADD | BPF_X: 39562258278SAlexei Starovoitov case BPF_ALU64 | BPF_SUB | BPF_X: 39662258278SAlexei Starovoitov case BPF_ALU64 | BPF_AND | BPF_X: 39762258278SAlexei Starovoitov case BPF_ALU64 | BPF_OR | BPF_X: 39862258278SAlexei Starovoitov case BPF_ALU64 | BPF_XOR | BPF_X: 39962258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 40062258278SAlexei Starovoitov case BPF_ADD: b2 = 0x01; break; 40162258278SAlexei Starovoitov case BPF_SUB: b2 = 0x29; break; 40262258278SAlexei Starovoitov case BPF_AND: b2 = 0x21; break; 40362258278SAlexei Starovoitov case BPF_OR: b2 = 0x09; break; 40462258278SAlexei Starovoitov case BPF_XOR: b2 = 0x31; break; 40562258278SAlexei Starovoitov } 40662258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 407e430f34eSAlexei Starovoitov EMIT1(add_2mod(0x48, dst_reg, src_reg)); 408e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg) || is_ereg(src_reg)) 409e430f34eSAlexei Starovoitov EMIT1(add_2mod(0x40, dst_reg, src_reg)); 410e430f34eSAlexei Starovoitov EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); 4110a14842fSEric Dumazet break; 41262258278SAlexei Starovoitov 413e430f34eSAlexei Starovoitov /* mov dst, src */ 41462258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOV | BPF_X: 415e430f34eSAlexei Starovoitov EMIT_mov(dst_reg, src_reg); 41662258278SAlexei Starovoitov break; 41762258278SAlexei Starovoitov 418e430f34eSAlexei Starovoitov /* mov32 dst, src */ 41962258278SAlexei Starovoitov case BPF_ALU | BPF_MOV | BPF_X: 420e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 421e430f34eSAlexei Starovoitov EMIT1(add_2mod(0x40, dst_reg, src_reg)); 422e430f34eSAlexei Starovoitov EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); 42362258278SAlexei Starovoitov break; 42462258278SAlexei Starovoitov 425e430f34eSAlexei Starovoitov /* neg dst */ 42662258278SAlexei Starovoitov case BPF_ALU | BPF_NEG: 42762258278SAlexei Starovoitov case BPF_ALU64 | BPF_NEG: 42862258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 429e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 430e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg)) 431e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 432e430f34eSAlexei Starovoitov EMIT2(0xF7, add_1reg(0xD8, dst_reg)); 43362258278SAlexei Starovoitov break; 43462258278SAlexei Starovoitov 43562258278SAlexei Starovoitov case BPF_ALU | BPF_ADD | BPF_K: 43662258278SAlexei Starovoitov case BPF_ALU | BPF_SUB | BPF_K: 43762258278SAlexei Starovoitov case BPF_ALU | BPF_AND | BPF_K: 43862258278SAlexei Starovoitov case BPF_ALU | BPF_OR | BPF_K: 43962258278SAlexei Starovoitov case BPF_ALU | BPF_XOR | BPF_K: 44062258278SAlexei Starovoitov case BPF_ALU64 | BPF_ADD | BPF_K: 44162258278SAlexei Starovoitov case BPF_ALU64 | BPF_SUB | BPF_K: 44262258278SAlexei Starovoitov case BPF_ALU64 | BPF_AND | BPF_K: 44362258278SAlexei Starovoitov case BPF_ALU64 | BPF_OR | BPF_K: 44462258278SAlexei Starovoitov case BPF_ALU64 | BPF_XOR | BPF_K: 44562258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 446e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 447e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg)) 448e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 44962258278SAlexei Starovoitov 45062258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 45162258278SAlexei Starovoitov case BPF_ADD: b3 = 0xC0; break; 45262258278SAlexei Starovoitov case BPF_SUB: b3 = 0xE8; break; 45362258278SAlexei Starovoitov case BPF_AND: b3 = 0xE0; break; 45462258278SAlexei Starovoitov case BPF_OR: b3 = 0xC8; break; 45562258278SAlexei Starovoitov case BPF_XOR: b3 = 0xF0; break; 45662258278SAlexei Starovoitov } 45762258278SAlexei Starovoitov 458e430f34eSAlexei Starovoitov if (is_imm8(imm32)) 459e430f34eSAlexei Starovoitov EMIT3(0x83, add_1reg(b3, dst_reg), imm32); 46062258278SAlexei Starovoitov else 461e430f34eSAlexei Starovoitov EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); 46262258278SAlexei Starovoitov break; 46362258278SAlexei Starovoitov 46462258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOV | BPF_K: 46562258278SAlexei Starovoitov /* optimization: if imm32 is positive, 46662258278SAlexei Starovoitov * use 'mov eax, imm32' (which zero-extends imm32) 46762258278SAlexei Starovoitov * to save 2 bytes 468d00a9dd2SEric Dumazet */ 469e430f34eSAlexei Starovoitov if (imm32 < 0) { 47062258278SAlexei Starovoitov /* 'mov rax, imm32' sign extends imm32 */ 471e430f34eSAlexei Starovoitov b1 = add_1mod(0x48, dst_reg); 47262258278SAlexei Starovoitov b2 = 0xC7; 47362258278SAlexei Starovoitov b3 = 0xC0; 474e430f34eSAlexei Starovoitov EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); 475aee636c4SEric Dumazet break; 476aee636c4SEric Dumazet } 4773b58908aSEric Dumazet 47862258278SAlexei Starovoitov case BPF_ALU | BPF_MOV | BPF_K: 479606c88a8SDaniel Borkmann /* optimization: if imm32 is zero, use 'xor <dst>,<dst>' 480606c88a8SDaniel Borkmann * to save 3 bytes. 481606c88a8SDaniel Borkmann */ 482606c88a8SDaniel Borkmann if (imm32 == 0) { 483606c88a8SDaniel Borkmann if (is_ereg(dst_reg)) 484606c88a8SDaniel Borkmann EMIT1(add_2mod(0x40, dst_reg, dst_reg)); 485606c88a8SDaniel Borkmann b2 = 0x31; /* xor */ 486606c88a8SDaniel Borkmann b3 = 0xC0; 487606c88a8SDaniel Borkmann EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); 488606c88a8SDaniel Borkmann break; 489606c88a8SDaniel Borkmann } 490606c88a8SDaniel Borkmann 49162258278SAlexei Starovoitov /* mov %eax, imm32 */ 492e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 493e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 494e430f34eSAlexei Starovoitov EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); 49562258278SAlexei Starovoitov break; 49662258278SAlexei Starovoitov 49702ab695bSAlexei Starovoitov case BPF_LD | BPF_IMM | BPF_DW: 498606c88a8SDaniel Borkmann /* optimization: if imm64 is zero, use 'xor <dst>,<dst>' 499606c88a8SDaniel Borkmann * to save 7 bytes. 500606c88a8SDaniel Borkmann */ 501606c88a8SDaniel Borkmann if (insn[0].imm == 0 && insn[1].imm == 0) { 502606c88a8SDaniel Borkmann b1 = add_2mod(0x48, dst_reg, dst_reg); 503606c88a8SDaniel Borkmann b2 = 0x31; /* xor */ 504606c88a8SDaniel Borkmann b3 = 0xC0; 505606c88a8SDaniel Borkmann EMIT3(b1, b2, add_2reg(b3, dst_reg, dst_reg)); 506606c88a8SDaniel Borkmann 507606c88a8SDaniel Borkmann insn++; 508606c88a8SDaniel Borkmann i++; 509606c88a8SDaniel Borkmann break; 510606c88a8SDaniel Borkmann } 511606c88a8SDaniel Borkmann 51202ab695bSAlexei Starovoitov /* movabsq %rax, imm64 */ 51302ab695bSAlexei Starovoitov EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); 51402ab695bSAlexei Starovoitov EMIT(insn[0].imm, 4); 51502ab695bSAlexei Starovoitov EMIT(insn[1].imm, 4); 51602ab695bSAlexei Starovoitov 51702ab695bSAlexei Starovoitov insn++; 51802ab695bSAlexei Starovoitov i++; 51902ab695bSAlexei Starovoitov break; 52002ab695bSAlexei Starovoitov 521e430f34eSAlexei Starovoitov /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ 52262258278SAlexei Starovoitov case BPF_ALU | BPF_MOD | BPF_X: 52362258278SAlexei Starovoitov case BPF_ALU | BPF_DIV | BPF_X: 52462258278SAlexei Starovoitov case BPF_ALU | BPF_MOD | BPF_K: 52562258278SAlexei Starovoitov case BPF_ALU | BPF_DIV | BPF_K: 52662258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOD | BPF_X: 52762258278SAlexei Starovoitov case BPF_ALU64 | BPF_DIV | BPF_X: 52862258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOD | BPF_K: 52962258278SAlexei Starovoitov case BPF_ALU64 | BPF_DIV | BPF_K: 53062258278SAlexei Starovoitov EMIT1(0x50); /* push rax */ 53162258278SAlexei Starovoitov EMIT1(0x52); /* push rdx */ 53262258278SAlexei Starovoitov 53362258278SAlexei Starovoitov if (BPF_SRC(insn->code) == BPF_X) 534e430f34eSAlexei Starovoitov /* mov r11, src_reg */ 535e430f34eSAlexei Starovoitov EMIT_mov(AUX_REG, src_reg); 53662258278SAlexei Starovoitov else 537e430f34eSAlexei Starovoitov /* mov r11, imm32 */ 538e430f34eSAlexei Starovoitov EMIT3_off32(0x49, 0xC7, 0xC3, imm32); 53962258278SAlexei Starovoitov 540e430f34eSAlexei Starovoitov /* mov rax, dst_reg */ 541e430f34eSAlexei Starovoitov EMIT_mov(BPF_REG_0, dst_reg); 54262258278SAlexei Starovoitov 54362258278SAlexei Starovoitov /* xor edx, edx 54462258278SAlexei Starovoitov * equivalent to 'xor rdx, rdx', but one byte less 54562258278SAlexei Starovoitov */ 54662258278SAlexei Starovoitov EMIT2(0x31, 0xd2); 54762258278SAlexei Starovoitov 54862258278SAlexei Starovoitov if (BPF_SRC(insn->code) == BPF_X) { 549e430f34eSAlexei Starovoitov /* if (src_reg == 0) return 0 */ 55062258278SAlexei Starovoitov 55162258278SAlexei Starovoitov /* cmp r11, 0 */ 55262258278SAlexei Starovoitov EMIT4(0x49, 0x83, 0xFB, 0x00); 55362258278SAlexei Starovoitov 55462258278SAlexei Starovoitov /* jne .+9 (skip over pop, pop, xor and jmp) */ 55562258278SAlexei Starovoitov EMIT2(X86_JNE, 1 + 1 + 2 + 5); 55662258278SAlexei Starovoitov EMIT1(0x5A); /* pop rdx */ 55762258278SAlexei Starovoitov EMIT1(0x58); /* pop rax */ 55862258278SAlexei Starovoitov EMIT2(0x31, 0xc0); /* xor eax, eax */ 55962258278SAlexei Starovoitov 56062258278SAlexei Starovoitov /* jmp cleanup_addr 56162258278SAlexei Starovoitov * addrs[i] - 11, because there are 11 bytes 56262258278SAlexei Starovoitov * after this insn: div, mov, pop, pop, mov 56362258278SAlexei Starovoitov */ 56462258278SAlexei Starovoitov jmp_offset = ctx->cleanup_addr - (addrs[i] - 11); 56562258278SAlexei Starovoitov EMIT1_off32(0xE9, jmp_offset); 56662258278SAlexei Starovoitov } 56762258278SAlexei Starovoitov 56862258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 56962258278SAlexei Starovoitov /* div r11 */ 57062258278SAlexei Starovoitov EMIT3(0x49, 0xF7, 0xF3); 57162258278SAlexei Starovoitov else 57262258278SAlexei Starovoitov /* div r11d */ 57362258278SAlexei Starovoitov EMIT3(0x41, 0xF7, 0xF3); 57462258278SAlexei Starovoitov 57562258278SAlexei Starovoitov if (BPF_OP(insn->code) == BPF_MOD) 57662258278SAlexei Starovoitov /* mov r11, rdx */ 57762258278SAlexei Starovoitov EMIT3(0x49, 0x89, 0xD3); 57862258278SAlexei Starovoitov else 57962258278SAlexei Starovoitov /* mov r11, rax */ 58062258278SAlexei Starovoitov EMIT3(0x49, 0x89, 0xC3); 58162258278SAlexei Starovoitov 58262258278SAlexei Starovoitov EMIT1(0x5A); /* pop rdx */ 58362258278SAlexei Starovoitov EMIT1(0x58); /* pop rax */ 58462258278SAlexei Starovoitov 585e430f34eSAlexei Starovoitov /* mov dst_reg, r11 */ 586e430f34eSAlexei Starovoitov EMIT_mov(dst_reg, AUX_REG); 58762258278SAlexei Starovoitov break; 58862258278SAlexei Starovoitov 58962258278SAlexei Starovoitov case BPF_ALU | BPF_MUL | BPF_K: 59062258278SAlexei Starovoitov case BPF_ALU | BPF_MUL | BPF_X: 59162258278SAlexei Starovoitov case BPF_ALU64 | BPF_MUL | BPF_K: 59262258278SAlexei Starovoitov case BPF_ALU64 | BPF_MUL | BPF_X: 59362258278SAlexei Starovoitov EMIT1(0x50); /* push rax */ 59462258278SAlexei Starovoitov EMIT1(0x52); /* push rdx */ 59562258278SAlexei Starovoitov 596e430f34eSAlexei Starovoitov /* mov r11, dst_reg */ 597e430f34eSAlexei Starovoitov EMIT_mov(AUX_REG, dst_reg); 59862258278SAlexei Starovoitov 59962258278SAlexei Starovoitov if (BPF_SRC(insn->code) == BPF_X) 600e430f34eSAlexei Starovoitov /* mov rax, src_reg */ 601e430f34eSAlexei Starovoitov EMIT_mov(BPF_REG_0, src_reg); 60262258278SAlexei Starovoitov else 603e430f34eSAlexei Starovoitov /* mov rax, imm32 */ 604e430f34eSAlexei Starovoitov EMIT3_off32(0x48, 0xC7, 0xC0, imm32); 60562258278SAlexei Starovoitov 60662258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 60762258278SAlexei Starovoitov EMIT1(add_1mod(0x48, AUX_REG)); 60862258278SAlexei Starovoitov else if (is_ereg(AUX_REG)) 60962258278SAlexei Starovoitov EMIT1(add_1mod(0x40, AUX_REG)); 61062258278SAlexei Starovoitov /* mul(q) r11 */ 61162258278SAlexei Starovoitov EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); 61262258278SAlexei Starovoitov 61362258278SAlexei Starovoitov /* mov r11, rax */ 61462258278SAlexei Starovoitov EMIT_mov(AUX_REG, BPF_REG_0); 61562258278SAlexei Starovoitov 61662258278SAlexei Starovoitov EMIT1(0x5A); /* pop rdx */ 61762258278SAlexei Starovoitov EMIT1(0x58); /* pop rax */ 61862258278SAlexei Starovoitov 619e430f34eSAlexei Starovoitov /* mov dst_reg, r11 */ 620e430f34eSAlexei Starovoitov EMIT_mov(dst_reg, AUX_REG); 62162258278SAlexei Starovoitov break; 62262258278SAlexei Starovoitov 62362258278SAlexei Starovoitov /* shifts */ 62462258278SAlexei Starovoitov case BPF_ALU | BPF_LSH | BPF_K: 62562258278SAlexei Starovoitov case BPF_ALU | BPF_RSH | BPF_K: 62662258278SAlexei Starovoitov case BPF_ALU | BPF_ARSH | BPF_K: 62762258278SAlexei Starovoitov case BPF_ALU64 | BPF_LSH | BPF_K: 62862258278SAlexei Starovoitov case BPF_ALU64 | BPF_RSH | BPF_K: 62962258278SAlexei Starovoitov case BPF_ALU64 | BPF_ARSH | BPF_K: 63062258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 631e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 632e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg)) 633e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 63462258278SAlexei Starovoitov 63562258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 63662258278SAlexei Starovoitov case BPF_LSH: b3 = 0xE0; break; 63762258278SAlexei Starovoitov case BPF_RSH: b3 = 0xE8; break; 63862258278SAlexei Starovoitov case BPF_ARSH: b3 = 0xF8; break; 63962258278SAlexei Starovoitov } 640e430f34eSAlexei Starovoitov EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); 64162258278SAlexei Starovoitov break; 64262258278SAlexei Starovoitov 64372b603eeSAlexei Starovoitov case BPF_ALU | BPF_LSH | BPF_X: 64472b603eeSAlexei Starovoitov case BPF_ALU | BPF_RSH | BPF_X: 64572b603eeSAlexei Starovoitov case BPF_ALU | BPF_ARSH | BPF_X: 64672b603eeSAlexei Starovoitov case BPF_ALU64 | BPF_LSH | BPF_X: 64772b603eeSAlexei Starovoitov case BPF_ALU64 | BPF_RSH | BPF_X: 64872b603eeSAlexei Starovoitov case BPF_ALU64 | BPF_ARSH | BPF_X: 64972b603eeSAlexei Starovoitov 65072b603eeSAlexei Starovoitov /* check for bad case when dst_reg == rcx */ 65172b603eeSAlexei Starovoitov if (dst_reg == BPF_REG_4) { 65272b603eeSAlexei Starovoitov /* mov r11, dst_reg */ 65372b603eeSAlexei Starovoitov EMIT_mov(AUX_REG, dst_reg); 65472b603eeSAlexei Starovoitov dst_reg = AUX_REG; 65572b603eeSAlexei Starovoitov } 65672b603eeSAlexei Starovoitov 65772b603eeSAlexei Starovoitov if (src_reg != BPF_REG_4) { /* common case */ 65872b603eeSAlexei Starovoitov EMIT1(0x51); /* push rcx */ 65972b603eeSAlexei Starovoitov 66072b603eeSAlexei Starovoitov /* mov rcx, src_reg */ 66172b603eeSAlexei Starovoitov EMIT_mov(BPF_REG_4, src_reg); 66272b603eeSAlexei Starovoitov } 66372b603eeSAlexei Starovoitov 66472b603eeSAlexei Starovoitov /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ 66572b603eeSAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 66672b603eeSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 66772b603eeSAlexei Starovoitov else if (is_ereg(dst_reg)) 66872b603eeSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 66972b603eeSAlexei Starovoitov 67072b603eeSAlexei Starovoitov switch (BPF_OP(insn->code)) { 67172b603eeSAlexei Starovoitov case BPF_LSH: b3 = 0xE0; break; 67272b603eeSAlexei Starovoitov case BPF_RSH: b3 = 0xE8; break; 67372b603eeSAlexei Starovoitov case BPF_ARSH: b3 = 0xF8; break; 67472b603eeSAlexei Starovoitov } 67572b603eeSAlexei Starovoitov EMIT2(0xD3, add_1reg(b3, dst_reg)); 67672b603eeSAlexei Starovoitov 67772b603eeSAlexei Starovoitov if (src_reg != BPF_REG_4) 67872b603eeSAlexei Starovoitov EMIT1(0x59); /* pop rcx */ 67972b603eeSAlexei Starovoitov 68072b603eeSAlexei Starovoitov if (insn->dst_reg == BPF_REG_4) 68172b603eeSAlexei Starovoitov /* mov dst_reg, r11 */ 68272b603eeSAlexei Starovoitov EMIT_mov(insn->dst_reg, AUX_REG); 68372b603eeSAlexei Starovoitov break; 68472b603eeSAlexei Starovoitov 68562258278SAlexei Starovoitov case BPF_ALU | BPF_END | BPF_FROM_BE: 686e430f34eSAlexei Starovoitov switch (imm32) { 68762258278SAlexei Starovoitov case 16: 68862258278SAlexei Starovoitov /* emit 'ror %ax, 8' to swap lower 2 bytes */ 68962258278SAlexei Starovoitov EMIT1(0x66); 690e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 69162258278SAlexei Starovoitov EMIT1(0x41); 692e430f34eSAlexei Starovoitov EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); 693343f845bSAlexei Starovoitov 694343f845bSAlexei Starovoitov /* emit 'movzwl eax, ax' */ 695343f845bSAlexei Starovoitov if (is_ereg(dst_reg)) 696343f845bSAlexei Starovoitov EMIT3(0x45, 0x0F, 0xB7); 697343f845bSAlexei Starovoitov else 698343f845bSAlexei Starovoitov EMIT2(0x0F, 0xB7); 699343f845bSAlexei Starovoitov EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); 70062258278SAlexei Starovoitov break; 70162258278SAlexei Starovoitov case 32: 70262258278SAlexei Starovoitov /* emit 'bswap eax' to swap lower 4 bytes */ 703e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 70462258278SAlexei Starovoitov EMIT2(0x41, 0x0F); 70562258278SAlexei Starovoitov else 70662258278SAlexei Starovoitov EMIT1(0x0F); 707e430f34eSAlexei Starovoitov EMIT1(add_1reg(0xC8, dst_reg)); 70862258278SAlexei Starovoitov break; 70962258278SAlexei Starovoitov case 64: 71062258278SAlexei Starovoitov /* emit 'bswap rax' to swap 8 bytes */ 711e430f34eSAlexei Starovoitov EMIT3(add_1mod(0x48, dst_reg), 0x0F, 712e430f34eSAlexei Starovoitov add_1reg(0xC8, dst_reg)); 71362258278SAlexei Starovoitov break; 71462258278SAlexei Starovoitov } 71562258278SAlexei Starovoitov break; 71662258278SAlexei Starovoitov 71762258278SAlexei Starovoitov case BPF_ALU | BPF_END | BPF_FROM_LE: 718343f845bSAlexei Starovoitov switch (imm32) { 719343f845bSAlexei Starovoitov case 16: 720343f845bSAlexei Starovoitov /* emit 'movzwl eax, ax' to zero extend 16-bit 721343f845bSAlexei Starovoitov * into 64 bit 722343f845bSAlexei Starovoitov */ 723343f845bSAlexei Starovoitov if (is_ereg(dst_reg)) 724343f845bSAlexei Starovoitov EMIT3(0x45, 0x0F, 0xB7); 725343f845bSAlexei Starovoitov else 726343f845bSAlexei Starovoitov EMIT2(0x0F, 0xB7); 727343f845bSAlexei Starovoitov EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); 728343f845bSAlexei Starovoitov break; 729343f845bSAlexei Starovoitov case 32: 730343f845bSAlexei Starovoitov /* emit 'mov eax, eax' to clear upper 32-bits */ 731343f845bSAlexei Starovoitov if (is_ereg(dst_reg)) 732343f845bSAlexei Starovoitov EMIT1(0x45); 733343f845bSAlexei Starovoitov EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); 734343f845bSAlexei Starovoitov break; 735343f845bSAlexei Starovoitov case 64: 736343f845bSAlexei Starovoitov /* nop */ 737343f845bSAlexei Starovoitov break; 738343f845bSAlexei Starovoitov } 73962258278SAlexei Starovoitov break; 74062258278SAlexei Starovoitov 741e430f34eSAlexei Starovoitov /* ST: *(u8*)(dst_reg + off) = imm */ 74262258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_B: 743e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 74462258278SAlexei Starovoitov EMIT2(0x41, 0xC6); 74562258278SAlexei Starovoitov else 74662258278SAlexei Starovoitov EMIT1(0xC6); 74762258278SAlexei Starovoitov goto st; 74862258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_H: 749e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 75062258278SAlexei Starovoitov EMIT3(0x66, 0x41, 0xC7); 75162258278SAlexei Starovoitov else 75262258278SAlexei Starovoitov EMIT2(0x66, 0xC7); 75362258278SAlexei Starovoitov goto st; 75462258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_W: 755e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 75662258278SAlexei Starovoitov EMIT2(0x41, 0xC7); 75762258278SAlexei Starovoitov else 75862258278SAlexei Starovoitov EMIT1(0xC7); 75962258278SAlexei Starovoitov goto st; 76062258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_DW: 761e430f34eSAlexei Starovoitov EMIT2(add_1mod(0x48, dst_reg), 0xC7); 76262258278SAlexei Starovoitov 76362258278SAlexei Starovoitov st: if (is_imm8(insn->off)) 764e430f34eSAlexei Starovoitov EMIT2(add_1reg(0x40, dst_reg), insn->off); 76562258278SAlexei Starovoitov else 766e430f34eSAlexei Starovoitov EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); 76762258278SAlexei Starovoitov 768e430f34eSAlexei Starovoitov EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); 76962258278SAlexei Starovoitov break; 77062258278SAlexei Starovoitov 771e430f34eSAlexei Starovoitov /* STX: *(u8*)(dst_reg + off) = src_reg */ 77262258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_B: 77362258278SAlexei Starovoitov /* emit 'mov byte ptr [rax + off], al' */ 774e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg) || 77562258278SAlexei Starovoitov /* have to add extra byte for x86 SIL, DIL regs */ 776e430f34eSAlexei Starovoitov src_reg == BPF_REG_1 || src_reg == BPF_REG_2) 777e430f34eSAlexei Starovoitov EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); 77862258278SAlexei Starovoitov else 77962258278SAlexei Starovoitov EMIT1(0x88); 78062258278SAlexei Starovoitov goto stx; 78162258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_H: 782e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 783e430f34eSAlexei Starovoitov EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); 78462258278SAlexei Starovoitov else 78562258278SAlexei Starovoitov EMIT2(0x66, 0x89); 78662258278SAlexei Starovoitov goto stx; 78762258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_W: 788e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 789e430f34eSAlexei Starovoitov EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); 79062258278SAlexei Starovoitov else 79162258278SAlexei Starovoitov EMIT1(0x89); 79262258278SAlexei Starovoitov goto stx; 79362258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_DW: 794e430f34eSAlexei Starovoitov EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); 79562258278SAlexei Starovoitov stx: if (is_imm8(insn->off)) 796e430f34eSAlexei Starovoitov EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); 79762258278SAlexei Starovoitov else 798e430f34eSAlexei Starovoitov EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), 79962258278SAlexei Starovoitov insn->off); 80062258278SAlexei Starovoitov break; 80162258278SAlexei Starovoitov 802e430f34eSAlexei Starovoitov /* LDX: dst_reg = *(u8*)(src_reg + off) */ 80362258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_B: 80462258278SAlexei Starovoitov /* emit 'movzx rax, byte ptr [rax + off]' */ 805e430f34eSAlexei Starovoitov EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); 80662258278SAlexei Starovoitov goto ldx; 80762258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_H: 80862258278SAlexei Starovoitov /* emit 'movzx rax, word ptr [rax + off]' */ 809e430f34eSAlexei Starovoitov EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); 81062258278SAlexei Starovoitov goto ldx; 81162258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_W: 81262258278SAlexei Starovoitov /* emit 'mov eax, dword ptr [rax+0x14]' */ 813e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 814e430f34eSAlexei Starovoitov EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); 81562258278SAlexei Starovoitov else 81662258278SAlexei Starovoitov EMIT1(0x8B); 81762258278SAlexei Starovoitov goto ldx; 81862258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_DW: 81962258278SAlexei Starovoitov /* emit 'mov rax, qword ptr [rax+0x14]' */ 820e430f34eSAlexei Starovoitov EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); 82162258278SAlexei Starovoitov ldx: /* if insn->off == 0 we can save one extra byte, but 82262258278SAlexei Starovoitov * special case of x86 r13 which always needs an offset 82362258278SAlexei Starovoitov * is not worth the hassle 82462258278SAlexei Starovoitov */ 82562258278SAlexei Starovoitov if (is_imm8(insn->off)) 826e430f34eSAlexei Starovoitov EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off); 82762258278SAlexei Starovoitov else 828e430f34eSAlexei Starovoitov EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), 82962258278SAlexei Starovoitov insn->off); 83062258278SAlexei Starovoitov break; 83162258278SAlexei Starovoitov 832e430f34eSAlexei Starovoitov /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ 83362258278SAlexei Starovoitov case BPF_STX | BPF_XADD | BPF_W: 83462258278SAlexei Starovoitov /* emit 'lock add dword ptr [rax + off], eax' */ 835e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 836e430f34eSAlexei Starovoitov EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); 83762258278SAlexei Starovoitov else 83862258278SAlexei Starovoitov EMIT2(0xF0, 0x01); 83962258278SAlexei Starovoitov goto xadd; 84062258278SAlexei Starovoitov case BPF_STX | BPF_XADD | BPF_DW: 841e430f34eSAlexei Starovoitov EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); 84262258278SAlexei Starovoitov xadd: if (is_imm8(insn->off)) 843e430f34eSAlexei Starovoitov EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); 84462258278SAlexei Starovoitov else 845e430f34eSAlexei Starovoitov EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), 84662258278SAlexei Starovoitov insn->off); 84762258278SAlexei Starovoitov break; 84862258278SAlexei Starovoitov 84962258278SAlexei Starovoitov /* call */ 85062258278SAlexei Starovoitov case BPF_JMP | BPF_CALL: 851e430f34eSAlexei Starovoitov func = (u8 *) __bpf_call_base + imm32; 85262258278SAlexei Starovoitov jmp_offset = func - (image + addrs[i]); 853e0ee9c12SAlexei Starovoitov if (seen_ld_abs) { 85417bedab2SMartin KaFai Lau reload_skb_data = bpf_helper_changes_pkt_data(func); 8554e10df9aSAlexei Starovoitov if (reload_skb_data) { 8564e10df9aSAlexei Starovoitov EMIT1(0x57); /* push %rdi */ 8574e10df9aSAlexei Starovoitov jmp_offset += 22; /* pop, mov, sub, mov */ 8584e10df9aSAlexei Starovoitov } else { 85962258278SAlexei Starovoitov EMIT2(0x41, 0x52); /* push %r10 */ 86062258278SAlexei Starovoitov EMIT2(0x41, 0x51); /* push %r9 */ 86162258278SAlexei Starovoitov /* need to adjust jmp offset, since 86262258278SAlexei Starovoitov * pop %r9, pop %r10 take 4 bytes after call insn 86362258278SAlexei Starovoitov */ 86462258278SAlexei Starovoitov jmp_offset += 4; 86562258278SAlexei Starovoitov } 8664e10df9aSAlexei Starovoitov } 867e430f34eSAlexei Starovoitov if (!imm32 || !is_simm32(jmp_offset)) { 86862258278SAlexei Starovoitov pr_err("unsupported bpf func %d addr %p image %p\n", 869e430f34eSAlexei Starovoitov imm32, func, image); 870f3c2af7bSAlexei Starovoitov return -EINVAL; 87162258278SAlexei Starovoitov } 87262258278SAlexei Starovoitov EMIT1_off32(0xE8, jmp_offset); 873e0ee9c12SAlexei Starovoitov if (seen_ld_abs) { 8744e10df9aSAlexei Starovoitov if (reload_skb_data) { 8754e10df9aSAlexei Starovoitov EMIT1(0x5F); /* pop %rdi */ 8764e10df9aSAlexei Starovoitov emit_load_skb_data_hlen(&prog); 8774e10df9aSAlexei Starovoitov } else { 87862258278SAlexei Starovoitov EMIT2(0x41, 0x59); /* pop %r9 */ 87962258278SAlexei Starovoitov EMIT2(0x41, 0x5A); /* pop %r10 */ 88062258278SAlexei Starovoitov } 8814e10df9aSAlexei Starovoitov } 88262258278SAlexei Starovoitov break; 88362258278SAlexei Starovoitov 88471189fa9SAlexei Starovoitov case BPF_JMP | BPF_TAIL_CALL: 885b52f00e6SAlexei Starovoitov emit_bpf_tail_call(&prog); 886b52f00e6SAlexei Starovoitov break; 887b52f00e6SAlexei Starovoitov 88862258278SAlexei Starovoitov /* cond jump */ 88962258278SAlexei Starovoitov case BPF_JMP | BPF_JEQ | BPF_X: 89062258278SAlexei Starovoitov case BPF_JMP | BPF_JNE | BPF_X: 89162258278SAlexei Starovoitov case BPF_JMP | BPF_JGT | BPF_X: 89252afc51eSDaniel Borkmann case BPF_JMP | BPF_JLT | BPF_X: 89362258278SAlexei Starovoitov case BPF_JMP | BPF_JGE | BPF_X: 89452afc51eSDaniel Borkmann case BPF_JMP | BPF_JLE | BPF_X: 89562258278SAlexei Starovoitov case BPF_JMP | BPF_JSGT | BPF_X: 89652afc51eSDaniel Borkmann case BPF_JMP | BPF_JSLT | BPF_X: 89762258278SAlexei Starovoitov case BPF_JMP | BPF_JSGE | BPF_X: 89852afc51eSDaniel Borkmann case BPF_JMP | BPF_JSLE | BPF_X: 899e430f34eSAlexei Starovoitov /* cmp dst_reg, src_reg */ 900e430f34eSAlexei Starovoitov EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39, 901e430f34eSAlexei Starovoitov add_2reg(0xC0, dst_reg, src_reg)); 90262258278SAlexei Starovoitov goto emit_cond_jmp; 90362258278SAlexei Starovoitov 90462258278SAlexei Starovoitov case BPF_JMP | BPF_JSET | BPF_X: 905e430f34eSAlexei Starovoitov /* test dst_reg, src_reg */ 906e430f34eSAlexei Starovoitov EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x85, 907e430f34eSAlexei Starovoitov add_2reg(0xC0, dst_reg, src_reg)); 90862258278SAlexei Starovoitov goto emit_cond_jmp; 90962258278SAlexei Starovoitov 91062258278SAlexei Starovoitov case BPF_JMP | BPF_JSET | BPF_K: 911e430f34eSAlexei Starovoitov /* test dst_reg, imm32 */ 912e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 913e430f34eSAlexei Starovoitov EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); 91462258278SAlexei Starovoitov goto emit_cond_jmp; 91562258278SAlexei Starovoitov 91662258278SAlexei Starovoitov case BPF_JMP | BPF_JEQ | BPF_K: 91762258278SAlexei Starovoitov case BPF_JMP | BPF_JNE | BPF_K: 91862258278SAlexei Starovoitov case BPF_JMP | BPF_JGT | BPF_K: 91952afc51eSDaniel Borkmann case BPF_JMP | BPF_JLT | BPF_K: 92062258278SAlexei Starovoitov case BPF_JMP | BPF_JGE | BPF_K: 92152afc51eSDaniel Borkmann case BPF_JMP | BPF_JLE | BPF_K: 92262258278SAlexei Starovoitov case BPF_JMP | BPF_JSGT | BPF_K: 92352afc51eSDaniel Borkmann case BPF_JMP | BPF_JSLT | BPF_K: 92462258278SAlexei Starovoitov case BPF_JMP | BPF_JSGE | BPF_K: 92552afc51eSDaniel Borkmann case BPF_JMP | BPF_JSLE | BPF_K: 926e430f34eSAlexei Starovoitov /* cmp dst_reg, imm8/32 */ 927e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 92862258278SAlexei Starovoitov 929e430f34eSAlexei Starovoitov if (is_imm8(imm32)) 930e430f34eSAlexei Starovoitov EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); 93162258278SAlexei Starovoitov else 932e430f34eSAlexei Starovoitov EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); 93362258278SAlexei Starovoitov 93462258278SAlexei Starovoitov emit_cond_jmp: /* convert BPF opcode to x86 */ 93562258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 93662258278SAlexei Starovoitov case BPF_JEQ: 93762258278SAlexei Starovoitov jmp_cond = X86_JE; 93862258278SAlexei Starovoitov break; 93962258278SAlexei Starovoitov case BPF_JSET: 94062258278SAlexei Starovoitov case BPF_JNE: 94162258278SAlexei Starovoitov jmp_cond = X86_JNE; 94262258278SAlexei Starovoitov break; 94362258278SAlexei Starovoitov case BPF_JGT: 94462258278SAlexei Starovoitov /* GT is unsigned '>', JA in x86 */ 94562258278SAlexei Starovoitov jmp_cond = X86_JA; 94662258278SAlexei Starovoitov break; 94752afc51eSDaniel Borkmann case BPF_JLT: 94852afc51eSDaniel Borkmann /* LT is unsigned '<', JB in x86 */ 94952afc51eSDaniel Borkmann jmp_cond = X86_JB; 95052afc51eSDaniel Borkmann break; 95162258278SAlexei Starovoitov case BPF_JGE: 95262258278SAlexei Starovoitov /* GE is unsigned '>=', JAE in x86 */ 95362258278SAlexei Starovoitov jmp_cond = X86_JAE; 95462258278SAlexei Starovoitov break; 95552afc51eSDaniel Borkmann case BPF_JLE: 95652afc51eSDaniel Borkmann /* LE is unsigned '<=', JBE in x86 */ 95752afc51eSDaniel Borkmann jmp_cond = X86_JBE; 95852afc51eSDaniel Borkmann break; 95962258278SAlexei Starovoitov case BPF_JSGT: 96062258278SAlexei Starovoitov /* signed '>', GT in x86 */ 96162258278SAlexei Starovoitov jmp_cond = X86_JG; 96262258278SAlexei Starovoitov break; 96352afc51eSDaniel Borkmann case BPF_JSLT: 96452afc51eSDaniel Borkmann /* signed '<', LT in x86 */ 96552afc51eSDaniel Borkmann jmp_cond = X86_JL; 96652afc51eSDaniel Borkmann break; 96762258278SAlexei Starovoitov case BPF_JSGE: 96862258278SAlexei Starovoitov /* signed '>=', GE in x86 */ 96962258278SAlexei Starovoitov jmp_cond = X86_JGE; 97062258278SAlexei Starovoitov break; 97152afc51eSDaniel Borkmann case BPF_JSLE: 97252afc51eSDaniel Borkmann /* signed '<=', LE in x86 */ 97352afc51eSDaniel Borkmann jmp_cond = X86_JLE; 97452afc51eSDaniel Borkmann break; 97562258278SAlexei Starovoitov default: /* to silence gcc warning */ 97662258278SAlexei Starovoitov return -EFAULT; 97762258278SAlexei Starovoitov } 97862258278SAlexei Starovoitov jmp_offset = addrs[i + insn->off] - addrs[i]; 97962258278SAlexei Starovoitov if (is_imm8(jmp_offset)) { 98062258278SAlexei Starovoitov EMIT2(jmp_cond, jmp_offset); 98162258278SAlexei Starovoitov } else if (is_simm32(jmp_offset)) { 98262258278SAlexei Starovoitov EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); 9833b58908aSEric Dumazet } else { 98462258278SAlexei Starovoitov pr_err("cond_jmp gen bug %llx\n", jmp_offset); 98562258278SAlexei Starovoitov return -EFAULT; 9863b58908aSEric Dumazet } 98762258278SAlexei Starovoitov 9883b58908aSEric Dumazet break; 98962258278SAlexei Starovoitov 99062258278SAlexei Starovoitov case BPF_JMP | BPF_JA: 99162258278SAlexei Starovoitov jmp_offset = addrs[i + insn->off] - addrs[i]; 99262258278SAlexei Starovoitov if (!jmp_offset) 99362258278SAlexei Starovoitov /* optimize out nop jumps */ 99462258278SAlexei Starovoitov break; 99562258278SAlexei Starovoitov emit_jmp: 99662258278SAlexei Starovoitov if (is_imm8(jmp_offset)) { 99762258278SAlexei Starovoitov EMIT2(0xEB, jmp_offset); 99862258278SAlexei Starovoitov } else if (is_simm32(jmp_offset)) { 99962258278SAlexei Starovoitov EMIT1_off32(0xE9, jmp_offset); 100062258278SAlexei Starovoitov } else { 100162258278SAlexei Starovoitov pr_err("jmp gen bug %llx\n", jmp_offset); 100262258278SAlexei Starovoitov return -EFAULT; 10033b58908aSEric Dumazet } 100462258278SAlexei Starovoitov break; 100562258278SAlexei Starovoitov 100662258278SAlexei Starovoitov case BPF_LD | BPF_IND | BPF_W: 100762258278SAlexei Starovoitov func = sk_load_word; 100862258278SAlexei Starovoitov goto common_load; 100962258278SAlexei Starovoitov case BPF_LD | BPF_ABS | BPF_W: 1010e430f34eSAlexei Starovoitov func = CHOOSE_LOAD_FUNC(imm32, sk_load_word); 1011e0ee9c12SAlexei Starovoitov common_load: 1012e0ee9c12SAlexei Starovoitov ctx->seen_ld_abs = seen_ld_abs = true; 101362258278SAlexei Starovoitov jmp_offset = func - (image + addrs[i]); 101462258278SAlexei Starovoitov if (!func || !is_simm32(jmp_offset)) { 101562258278SAlexei Starovoitov pr_err("unsupported bpf func %d addr %p image %p\n", 1016e430f34eSAlexei Starovoitov imm32, func, image); 101762258278SAlexei Starovoitov return -EINVAL; 101862258278SAlexei Starovoitov } 101962258278SAlexei Starovoitov if (BPF_MODE(insn->code) == BPF_ABS) { 102062258278SAlexei Starovoitov /* mov %esi, imm32 */ 1021e430f34eSAlexei Starovoitov EMIT1_off32(0xBE, imm32); 102262258278SAlexei Starovoitov } else { 1023e430f34eSAlexei Starovoitov /* mov %rsi, src_reg */ 1024e430f34eSAlexei Starovoitov EMIT_mov(BPF_REG_2, src_reg); 1025e430f34eSAlexei Starovoitov if (imm32) { 1026e430f34eSAlexei Starovoitov if (is_imm8(imm32)) 102762258278SAlexei Starovoitov /* add %esi, imm8 */ 1028e430f34eSAlexei Starovoitov EMIT3(0x83, 0xC6, imm32); 102962258278SAlexei Starovoitov else 103062258278SAlexei Starovoitov /* add %esi, imm32 */ 1031e430f34eSAlexei Starovoitov EMIT2_off32(0x81, 0xC6, imm32); 103262258278SAlexei Starovoitov } 103362258278SAlexei Starovoitov } 103462258278SAlexei Starovoitov /* skb pointer is in R6 (%rbx), it will be copied into 103562258278SAlexei Starovoitov * %rdi if skb_copy_bits() call is necessary. 103662258278SAlexei Starovoitov * sk_load_* helpers also use %r10 and %r9d. 103762258278SAlexei Starovoitov * See bpf_jit.S 103862258278SAlexei Starovoitov */ 1039959a7579SDaniel Borkmann if (seen_ax_reg) 1040959a7579SDaniel Borkmann /* r10 = skb->data, mov %r10, off32(%rbx) */ 1041959a7579SDaniel Borkmann EMIT3_off32(0x4c, 0x8b, 0x93, 1042959a7579SDaniel Borkmann offsetof(struct sk_buff, data)); 104362258278SAlexei Starovoitov EMIT1_off32(0xE8, jmp_offset); /* call */ 10440a14842fSEric Dumazet break; 104562258278SAlexei Starovoitov 104662258278SAlexei Starovoitov case BPF_LD | BPF_IND | BPF_H: 104762258278SAlexei Starovoitov func = sk_load_half; 104862258278SAlexei Starovoitov goto common_load; 104962258278SAlexei Starovoitov case BPF_LD | BPF_ABS | BPF_H: 1050e430f34eSAlexei Starovoitov func = CHOOSE_LOAD_FUNC(imm32, sk_load_half); 10510a14842fSEric Dumazet goto common_load; 105262258278SAlexei Starovoitov case BPF_LD | BPF_IND | BPF_B: 105362258278SAlexei Starovoitov func = sk_load_byte; 105462258278SAlexei Starovoitov goto common_load; 105562258278SAlexei Starovoitov case BPF_LD | BPF_ABS | BPF_B: 1056e430f34eSAlexei Starovoitov func = CHOOSE_LOAD_FUNC(imm32, sk_load_byte); 10570a14842fSEric Dumazet goto common_load; 10580a14842fSEric Dumazet 105962258278SAlexei Starovoitov case BPF_JMP | BPF_EXIT: 1060769e0de6SAlexei Starovoitov if (seen_exit) { 106162258278SAlexei Starovoitov jmp_offset = ctx->cleanup_addr - addrs[i]; 106262258278SAlexei Starovoitov goto emit_jmp; 106362258278SAlexei Starovoitov } 1064769e0de6SAlexei Starovoitov seen_exit = true; 106562258278SAlexei Starovoitov /* update cleanup_addr */ 106662258278SAlexei Starovoitov ctx->cleanup_addr = proglen; 1067177366bfSAlexei Starovoitov /* mov rbx, qword ptr [rbp+0] */ 1068177366bfSAlexei Starovoitov EMIT4(0x48, 0x8B, 0x5D, 0); 1069177366bfSAlexei Starovoitov /* mov r13, qword ptr [rbp+8] */ 1070177366bfSAlexei Starovoitov EMIT4(0x4C, 0x8B, 0x6D, 8); 1071177366bfSAlexei Starovoitov /* mov r14, qword ptr [rbp+16] */ 1072177366bfSAlexei Starovoitov EMIT4(0x4C, 0x8B, 0x75, 16); 1073177366bfSAlexei Starovoitov /* mov r15, qword ptr [rbp+24] */ 1074177366bfSAlexei Starovoitov EMIT4(0x4C, 0x8B, 0x7D, 24); 10750a14842fSEric Dumazet 1076177366bfSAlexei Starovoitov /* add rbp, AUX_STACK_SPACE */ 1077177366bfSAlexei Starovoitov EMIT4(0x48, 0x83, 0xC5, AUX_STACK_SPACE); 107862258278SAlexei Starovoitov EMIT1(0xC9); /* leave */ 107962258278SAlexei Starovoitov EMIT1(0xC3); /* ret */ 10800a14842fSEric Dumazet break; 10810a14842fSEric Dumazet 10820a14842fSEric Dumazet default: 108362258278SAlexei Starovoitov /* By design x64 JIT should support all BPF instructions 108462258278SAlexei Starovoitov * This error will be seen if new instruction was added 108562258278SAlexei Starovoitov * to interpreter, but not to JIT 10867ae457c1SAlexei Starovoitov * or if there is junk in bpf_prog 108762258278SAlexei Starovoitov */ 108862258278SAlexei Starovoitov pr_err("bpf_jit: unknown opcode %02x\n", insn->code); 1089f3c2af7bSAlexei Starovoitov return -EINVAL; 10900a14842fSEric Dumazet } 109162258278SAlexei Starovoitov 10920a14842fSEric Dumazet ilen = prog - temp; 1093e0ee9c12SAlexei Starovoitov if (ilen > BPF_MAX_INSN_SIZE) { 10949383191dSDaniel Borkmann pr_err("bpf_jit: fatal insn size error\n"); 1095e0ee9c12SAlexei Starovoitov return -EFAULT; 1096e0ee9c12SAlexei Starovoitov } 1097e0ee9c12SAlexei Starovoitov 10980a14842fSEric Dumazet if (image) { 10990a14842fSEric Dumazet if (unlikely(proglen + ilen > oldproglen)) { 11009383191dSDaniel Borkmann pr_err("bpf_jit: fatal error\n"); 1101f3c2af7bSAlexei Starovoitov return -EFAULT; 11020a14842fSEric Dumazet } 11030a14842fSEric Dumazet memcpy(image + proglen, temp, ilen); 11040a14842fSEric Dumazet } 11050a14842fSEric Dumazet proglen += ilen; 11060a14842fSEric Dumazet addrs[i] = proglen; 11070a14842fSEric Dumazet prog = temp; 11080a14842fSEric Dumazet } 1109f3c2af7bSAlexei Starovoitov return proglen; 1110f3c2af7bSAlexei Starovoitov } 1111f3c2af7bSAlexei Starovoitov 1112d1c55ab5SDaniel Borkmann struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) 111362258278SAlexei Starovoitov { 1114f3c2af7bSAlexei Starovoitov struct bpf_binary_header *header = NULL; 1115959a7579SDaniel Borkmann struct bpf_prog *tmp, *orig_prog = prog; 1116f3c2af7bSAlexei Starovoitov int proglen, oldproglen = 0; 1117f3c2af7bSAlexei Starovoitov struct jit_context ctx = {}; 1118959a7579SDaniel Borkmann bool tmp_blinded = false; 1119f3c2af7bSAlexei Starovoitov u8 *image = NULL; 1120f3c2af7bSAlexei Starovoitov int *addrs; 1121f3c2af7bSAlexei Starovoitov int pass; 1122f3c2af7bSAlexei Starovoitov int i; 1123f3c2af7bSAlexei Starovoitov 1124f3c2af7bSAlexei Starovoitov if (!bpf_jit_enable) 1125959a7579SDaniel Borkmann return orig_prog; 1126959a7579SDaniel Borkmann 1127959a7579SDaniel Borkmann tmp = bpf_jit_blind_constants(prog); 1128959a7579SDaniel Borkmann /* If blinding was requested and we failed during blinding, 1129959a7579SDaniel Borkmann * we must fall back to the interpreter. 1130959a7579SDaniel Borkmann */ 1131959a7579SDaniel Borkmann if (IS_ERR(tmp)) 1132959a7579SDaniel Borkmann return orig_prog; 1133959a7579SDaniel Borkmann if (tmp != prog) { 1134959a7579SDaniel Borkmann tmp_blinded = true; 1135959a7579SDaniel Borkmann prog = tmp; 1136959a7579SDaniel Borkmann } 1137f3c2af7bSAlexei Starovoitov 1138f3c2af7bSAlexei Starovoitov addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL); 1139959a7579SDaniel Borkmann if (!addrs) { 1140959a7579SDaniel Borkmann prog = orig_prog; 1141959a7579SDaniel Borkmann goto out; 1142959a7579SDaniel Borkmann } 1143f3c2af7bSAlexei Starovoitov 1144f3c2af7bSAlexei Starovoitov /* Before first pass, make a rough estimation of addrs[] 1145f3c2af7bSAlexei Starovoitov * each bpf instruction is translated to less than 64 bytes 1146f3c2af7bSAlexei Starovoitov */ 1147f3c2af7bSAlexei Starovoitov for (proglen = 0, i = 0; i < prog->len; i++) { 1148f3c2af7bSAlexei Starovoitov proglen += 64; 1149f3c2af7bSAlexei Starovoitov addrs[i] = proglen; 1150f3c2af7bSAlexei Starovoitov } 1151f3c2af7bSAlexei Starovoitov ctx.cleanup_addr = proglen; 1152f3c2af7bSAlexei Starovoitov 11533f7352bfSAlexei Starovoitov /* JITed image shrinks with every pass and the loop iterates 11543f7352bfSAlexei Starovoitov * until the image stops shrinking. Very large bpf programs 11553f7352bfSAlexei Starovoitov * may converge on the last pass. In such case do one more 11563f7352bfSAlexei Starovoitov * pass to emit the final image 11573f7352bfSAlexei Starovoitov */ 11583f7352bfSAlexei Starovoitov for (pass = 0; pass < 10 || image; pass++) { 1159f3c2af7bSAlexei Starovoitov proglen = do_jit(prog, addrs, image, oldproglen, &ctx); 1160f3c2af7bSAlexei Starovoitov if (proglen <= 0) { 1161f3c2af7bSAlexei Starovoitov image = NULL; 1162f3c2af7bSAlexei Starovoitov if (header) 1163738cbe72SDaniel Borkmann bpf_jit_binary_free(header); 1164959a7579SDaniel Borkmann prog = orig_prog; 1165959a7579SDaniel Borkmann goto out_addrs; 1166f3c2af7bSAlexei Starovoitov } 11670a14842fSEric Dumazet if (image) { 1168e0ee9c12SAlexei Starovoitov if (proglen != oldproglen) { 1169f3c2af7bSAlexei Starovoitov pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", 1170f3c2af7bSAlexei Starovoitov proglen, oldproglen); 1171959a7579SDaniel Borkmann prog = orig_prog; 1172959a7579SDaniel Borkmann goto out_addrs; 1173e0ee9c12SAlexei Starovoitov } 11740a14842fSEric Dumazet break; 11750a14842fSEric Dumazet } 11760a14842fSEric Dumazet if (proglen == oldproglen) { 1177738cbe72SDaniel Borkmann header = bpf_jit_binary_alloc(proglen, &image, 1178738cbe72SDaniel Borkmann 1, jit_fill_hole); 1179959a7579SDaniel Borkmann if (!header) { 1180959a7579SDaniel Borkmann prog = orig_prog; 1181959a7579SDaniel Borkmann goto out_addrs; 1182959a7579SDaniel Borkmann } 11830a14842fSEric Dumazet } 11840a14842fSEric Dumazet oldproglen = proglen; 11850a14842fSEric Dumazet } 118679617801SDaniel Borkmann 11870a14842fSEric Dumazet if (bpf_jit_enable > 1) 1188485d6511SDaniel Borkmann bpf_jit_dump(prog->len, proglen, pass + 1, image); 11890a14842fSEric Dumazet 11900a14842fSEric Dumazet if (image) { 1191314beb9bSEric Dumazet bpf_flush_icache(header, image + proglen); 11929d876e79SDaniel Borkmann bpf_jit_binary_lock_ro(header); 1193f3c2af7bSAlexei Starovoitov prog->bpf_func = (void *)image; 1194a91263d5SDaniel Borkmann prog->jited = 1; 1195783d28ddSMartin KaFai Lau prog->jited_len = proglen; 11969d5ecb09SDaniel Borkmann } else { 11979d5ecb09SDaniel Borkmann prog = orig_prog; 11980a14842fSEric Dumazet } 1199959a7579SDaniel Borkmann 1200959a7579SDaniel Borkmann out_addrs: 12010a14842fSEric Dumazet kfree(addrs); 1202959a7579SDaniel Borkmann out: 1203959a7579SDaniel Borkmann if (tmp_blinded) 1204959a7579SDaniel Borkmann bpf_jit_prog_release_other(prog, prog == orig_prog ? 1205959a7579SDaniel Borkmann tmp : orig_prog); 1206d1c55ab5SDaniel Borkmann return prog; 12070a14842fSEric Dumazet } 1208