1b886d83cSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2a2c7a983SIngo Molnar /* 3a2c7a983SIngo Molnar * bpf_jit_comp.c: BPF JIT compiler 40a14842fSEric Dumazet * 53b58908aSEric Dumazet * Copyright (C) 2011-2013 Eric Dumazet (eric.dumazet@gmail.com) 662258278SAlexei Starovoitov * Internal BPF Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 70a14842fSEric Dumazet */ 80a14842fSEric Dumazet #include <linux/netdevice.h> 90a14842fSEric Dumazet #include <linux/filter.h> 10855ddb56SEric Dumazet #include <linux/if_vlan.h> 1171d22d58SDaniel Borkmann #include <linux/bpf.h> 125964b200SAlexei Starovoitov #include <linux/memory.h> 1375ccbef6SBjörn Töpel #include <linux/sort.h> 143dec541bSAlexei Starovoitov #include <asm/extable.h> 15d1163651SLaura Abbott #include <asm/set_memory.h> 16a493a87fSDaniel Borkmann #include <asm/nospec-branch.h> 175964b200SAlexei Starovoitov #include <asm/text-patching.h> 1875ccbef6SBjörn Töpel #include <asm/asm-prototypes.h> 190a14842fSEric Dumazet 205cccc702SJoe Perches static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) 210a14842fSEric Dumazet { 220a14842fSEric Dumazet if (len == 1) 230a14842fSEric Dumazet *ptr = bytes; 240a14842fSEric Dumazet else if (len == 2) 250a14842fSEric Dumazet *(u16 *)ptr = bytes; 260a14842fSEric Dumazet else { 270a14842fSEric Dumazet *(u32 *)ptr = bytes; 280a14842fSEric Dumazet barrier(); 290a14842fSEric Dumazet } 300a14842fSEric Dumazet return ptr + len; 310a14842fSEric Dumazet } 320a14842fSEric Dumazet 33b52f00e6SAlexei Starovoitov #define EMIT(bytes, len) \ 34b52f00e6SAlexei Starovoitov do { prog = emit_code(prog, bytes, len); cnt += len; } while (0) 350a14842fSEric Dumazet 360a14842fSEric Dumazet #define EMIT1(b1) EMIT(b1, 1) 370a14842fSEric Dumazet #define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2) 380a14842fSEric Dumazet #define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3) 390a14842fSEric Dumazet #define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4) 40a2c7a983SIngo Molnar 4162258278SAlexei Starovoitov #define EMIT1_off32(b1, off) \ 4262258278SAlexei Starovoitov do { EMIT1(b1); EMIT(off, 4); } while (0) 4362258278SAlexei Starovoitov #define EMIT2_off32(b1, b2, off) \ 4462258278SAlexei Starovoitov do { EMIT2(b1, b2); EMIT(off, 4); } while (0) 4562258278SAlexei Starovoitov #define EMIT3_off32(b1, b2, b3, off) \ 4662258278SAlexei Starovoitov do { EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) 4762258278SAlexei Starovoitov #define EMIT4_off32(b1, b2, b3, b4, off) \ 4862258278SAlexei Starovoitov do { EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) 490a14842fSEric Dumazet 505cccc702SJoe Perches static bool is_imm8(int value) 510a14842fSEric Dumazet { 520a14842fSEric Dumazet return value <= 127 && value >= -128; 530a14842fSEric Dumazet } 540a14842fSEric Dumazet 555cccc702SJoe Perches static bool is_simm32(s64 value) 560a14842fSEric Dumazet { 5762258278SAlexei Starovoitov return value == (s64)(s32)value; 580a14842fSEric Dumazet } 590a14842fSEric Dumazet 606fe8b9c1SDaniel Borkmann static bool is_uimm32(u64 value) 616fe8b9c1SDaniel Borkmann { 626fe8b9c1SDaniel Borkmann return value == (u64)(u32)value; 636fe8b9c1SDaniel Borkmann } 646fe8b9c1SDaniel Borkmann 65e430f34eSAlexei Starovoitov /* mov dst, src */ 66e430f34eSAlexei Starovoitov #define EMIT_mov(DST, SRC) \ 67a2c7a983SIngo Molnar do { \ 68a2c7a983SIngo Molnar if (DST != SRC) \ 69e430f34eSAlexei Starovoitov EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ 700a14842fSEric Dumazet } while (0) 710a14842fSEric Dumazet 7262258278SAlexei Starovoitov static int bpf_size_to_x86_bytes(int bpf_size) 7362258278SAlexei Starovoitov { 7462258278SAlexei Starovoitov if (bpf_size == BPF_W) 7562258278SAlexei Starovoitov return 4; 7662258278SAlexei Starovoitov else if (bpf_size == BPF_H) 7762258278SAlexei Starovoitov return 2; 7862258278SAlexei Starovoitov else if (bpf_size == BPF_B) 7962258278SAlexei Starovoitov return 1; 8062258278SAlexei Starovoitov else if (bpf_size == BPF_DW) 8162258278SAlexei Starovoitov return 4; /* imm32 */ 8262258278SAlexei Starovoitov else 8362258278SAlexei Starovoitov return 0; 8462258278SAlexei Starovoitov } 8562258278SAlexei Starovoitov 86a2c7a983SIngo Molnar /* 87a2c7a983SIngo Molnar * 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 9652afc51eSDaniel Borkmann #define X86_JL 0x7C 9762258278SAlexei Starovoitov #define X86_JGE 0x7D 9852afc51eSDaniel Borkmann #define X86_JLE 0x7E 9962258278SAlexei Starovoitov #define X86_JG 0x7F 1000a14842fSEric Dumazet 101a2c7a983SIngo Molnar /* Pick a register outside of BPF range for JIT internal work */ 102959a7579SDaniel Borkmann #define AUX_REG (MAX_BPF_JIT_REG + 1) 103fec56f58SAlexei Starovoitov #define X86_REG_R9 (MAX_BPF_JIT_REG + 2) 10462258278SAlexei Starovoitov 105a2c7a983SIngo Molnar /* 106a2c7a983SIngo Molnar * The following table maps BPF registers to x86-64 registers. 107959a7579SDaniel Borkmann * 108a2c7a983SIngo Molnar * x86-64 register R12 is unused, since if used as base address 109959a7579SDaniel Borkmann * register in load/store instructions, it always needs an 110959a7579SDaniel Borkmann * extra byte of encoding and is callee saved. 111959a7579SDaniel Borkmann * 112fec56f58SAlexei Starovoitov * x86-64 register R9 is not used by BPF programs, but can be used by BPF 113fec56f58SAlexei Starovoitov * trampoline. x86-64 register R10 is used for blinding (if enabled). 11462258278SAlexei Starovoitov */ 11562258278SAlexei Starovoitov static const int reg2hex[] = { 116a2c7a983SIngo Molnar [BPF_REG_0] = 0, /* RAX */ 117a2c7a983SIngo Molnar [BPF_REG_1] = 7, /* RDI */ 118a2c7a983SIngo Molnar [BPF_REG_2] = 6, /* RSI */ 119a2c7a983SIngo Molnar [BPF_REG_3] = 2, /* RDX */ 120a2c7a983SIngo Molnar [BPF_REG_4] = 1, /* RCX */ 121a2c7a983SIngo Molnar [BPF_REG_5] = 0, /* R8 */ 122a2c7a983SIngo Molnar [BPF_REG_6] = 3, /* RBX callee saved */ 123a2c7a983SIngo Molnar [BPF_REG_7] = 5, /* R13 callee saved */ 124a2c7a983SIngo Molnar [BPF_REG_8] = 6, /* R14 callee saved */ 125a2c7a983SIngo Molnar [BPF_REG_9] = 7, /* R15 callee saved */ 126a2c7a983SIngo Molnar [BPF_REG_FP] = 5, /* RBP readonly */ 127a2c7a983SIngo Molnar [BPF_REG_AX] = 2, /* R10 temp register */ 128a2c7a983SIngo Molnar [AUX_REG] = 3, /* R11 temp register */ 129fec56f58SAlexei Starovoitov [X86_REG_R9] = 1, /* R9 register, 6th function argument */ 13062258278SAlexei Starovoitov }; 13162258278SAlexei Starovoitov 1323dec541bSAlexei Starovoitov static const int reg2pt_regs[] = { 1333dec541bSAlexei Starovoitov [BPF_REG_0] = offsetof(struct pt_regs, ax), 1343dec541bSAlexei Starovoitov [BPF_REG_1] = offsetof(struct pt_regs, di), 1353dec541bSAlexei Starovoitov [BPF_REG_2] = offsetof(struct pt_regs, si), 1363dec541bSAlexei Starovoitov [BPF_REG_3] = offsetof(struct pt_regs, dx), 1373dec541bSAlexei Starovoitov [BPF_REG_4] = offsetof(struct pt_regs, cx), 1383dec541bSAlexei Starovoitov [BPF_REG_5] = offsetof(struct pt_regs, r8), 1393dec541bSAlexei Starovoitov [BPF_REG_6] = offsetof(struct pt_regs, bx), 1403dec541bSAlexei Starovoitov [BPF_REG_7] = offsetof(struct pt_regs, r13), 1413dec541bSAlexei Starovoitov [BPF_REG_8] = offsetof(struct pt_regs, r14), 1423dec541bSAlexei Starovoitov [BPF_REG_9] = offsetof(struct pt_regs, r15), 1433dec541bSAlexei Starovoitov }; 1443dec541bSAlexei Starovoitov 145a2c7a983SIngo Molnar /* 146a2c7a983SIngo Molnar * is_ereg() == true if BPF register 'reg' maps to x86-64 r8..r15 14762258278SAlexei Starovoitov * which need extra byte of encoding. 14862258278SAlexei Starovoitov * rax,rcx,...,rbp have simpler encoding 14962258278SAlexei Starovoitov */ 1505cccc702SJoe Perches static bool is_ereg(u32 reg) 15162258278SAlexei Starovoitov { 152d148134bSJoe Perches return (1 << reg) & (BIT(BPF_REG_5) | 153d148134bSJoe Perches BIT(AUX_REG) | 154d148134bSJoe Perches BIT(BPF_REG_7) | 155d148134bSJoe Perches BIT(BPF_REG_8) | 156959a7579SDaniel Borkmann BIT(BPF_REG_9) | 157fec56f58SAlexei Starovoitov BIT(X86_REG_R9) | 158959a7579SDaniel Borkmann BIT(BPF_REG_AX)); 15962258278SAlexei Starovoitov } 16062258278SAlexei Starovoitov 161aee194b1SLuke Nelson /* 162aee194b1SLuke Nelson * is_ereg_8l() == true if BPF register 'reg' is mapped to access x86-64 163aee194b1SLuke Nelson * lower 8-bit registers dil,sil,bpl,spl,r8b..r15b, which need extra byte 164aee194b1SLuke Nelson * of encoding. al,cl,dl,bl have simpler encoding. 165aee194b1SLuke Nelson */ 166aee194b1SLuke Nelson static bool is_ereg_8l(u32 reg) 167aee194b1SLuke Nelson { 168aee194b1SLuke Nelson return is_ereg(reg) || 169aee194b1SLuke Nelson (1 << reg) & (BIT(BPF_REG_1) | 170aee194b1SLuke Nelson BIT(BPF_REG_2) | 171aee194b1SLuke Nelson BIT(BPF_REG_FP)); 172aee194b1SLuke Nelson } 173aee194b1SLuke Nelson 174de0a444dSDaniel Borkmann static bool is_axreg(u32 reg) 175de0a444dSDaniel Borkmann { 176de0a444dSDaniel Borkmann return reg == BPF_REG_0; 177de0a444dSDaniel Borkmann } 178de0a444dSDaniel Borkmann 179a2c7a983SIngo Molnar /* Add modifiers if 'reg' maps to x86-64 registers R8..R15 */ 1805cccc702SJoe Perches static u8 add_1mod(u8 byte, u32 reg) 18162258278SAlexei Starovoitov { 18262258278SAlexei Starovoitov if (is_ereg(reg)) 18362258278SAlexei Starovoitov byte |= 1; 18462258278SAlexei Starovoitov return byte; 18562258278SAlexei Starovoitov } 18662258278SAlexei Starovoitov 1875cccc702SJoe Perches static u8 add_2mod(u8 byte, u32 r1, u32 r2) 18862258278SAlexei Starovoitov { 18962258278SAlexei Starovoitov if (is_ereg(r1)) 19062258278SAlexei Starovoitov byte |= 1; 19162258278SAlexei Starovoitov if (is_ereg(r2)) 19262258278SAlexei Starovoitov byte |= 4; 19362258278SAlexei Starovoitov return byte; 19462258278SAlexei Starovoitov } 19562258278SAlexei Starovoitov 196a2c7a983SIngo Molnar /* Encode 'dst_reg' register into x86-64 opcode 'byte' */ 1975cccc702SJoe Perches static u8 add_1reg(u8 byte, u32 dst_reg) 19862258278SAlexei Starovoitov { 199e430f34eSAlexei Starovoitov return byte + reg2hex[dst_reg]; 20062258278SAlexei Starovoitov } 20162258278SAlexei Starovoitov 202a2c7a983SIngo Molnar /* Encode 'dst_reg' and 'src_reg' registers into x86-64 opcode 'byte' */ 2035cccc702SJoe Perches static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) 20462258278SAlexei Starovoitov { 205e430f34eSAlexei Starovoitov return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); 20662258278SAlexei Starovoitov } 20762258278SAlexei Starovoitov 208738cbe72SDaniel Borkmann static void jit_fill_hole(void *area, unsigned int size) 209738cbe72SDaniel Borkmann { 210a2c7a983SIngo Molnar /* Fill whole space with INT3 instructions */ 211738cbe72SDaniel Borkmann memset(area, 0xcc, size); 212738cbe72SDaniel Borkmann } 213738cbe72SDaniel Borkmann 214f3c2af7bSAlexei Starovoitov struct jit_context { 215a2c7a983SIngo Molnar int cleanup_addr; /* Epilogue code offset */ 216f3c2af7bSAlexei Starovoitov }; 217f3c2af7bSAlexei Starovoitov 218a2c7a983SIngo Molnar /* Maximum number of bytes emitted while JITing one eBPF insn */ 219e0ee9c12SAlexei Starovoitov #define BPF_MAX_INSN_SIZE 128 220e0ee9c12SAlexei Starovoitov #define BPF_INSN_SAFETY 64 2214b3da77bSDaniel Borkmann 2224b3da77bSDaniel Borkmann /* Number of bytes emit_patch() needs to generate instructions */ 2234b3da77bSDaniel Borkmann #define X86_PATCH_SIZE 5 224ebf7d1f5SMaciej Fijalkowski /* Number of bytes that will be skipped on tailcall */ 225ebf7d1f5SMaciej Fijalkowski #define X86_TAIL_CALL_OFFSET 11 226e0ee9c12SAlexei Starovoitov 227ebf7d1f5SMaciej Fijalkowski static void push_callee_regs(u8 **pprog, bool *callee_regs_used) 228ebf7d1f5SMaciej Fijalkowski { 229ebf7d1f5SMaciej Fijalkowski u8 *prog = *pprog; 230ebf7d1f5SMaciej Fijalkowski int cnt = 0; 231ebf7d1f5SMaciej Fijalkowski 232ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[0]) 233ebf7d1f5SMaciej Fijalkowski EMIT1(0x53); /* push rbx */ 234ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[1]) 235ebf7d1f5SMaciej Fijalkowski EMIT2(0x41, 0x55); /* push r13 */ 236ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[2]) 237ebf7d1f5SMaciej Fijalkowski EMIT2(0x41, 0x56); /* push r14 */ 238ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[3]) 239ebf7d1f5SMaciej Fijalkowski EMIT2(0x41, 0x57); /* push r15 */ 240ebf7d1f5SMaciej Fijalkowski *pprog = prog; 241ebf7d1f5SMaciej Fijalkowski } 242ebf7d1f5SMaciej Fijalkowski 243ebf7d1f5SMaciej Fijalkowski static void pop_callee_regs(u8 **pprog, bool *callee_regs_used) 244ebf7d1f5SMaciej Fijalkowski { 245ebf7d1f5SMaciej Fijalkowski u8 *prog = *pprog; 246ebf7d1f5SMaciej Fijalkowski int cnt = 0; 247ebf7d1f5SMaciej Fijalkowski 248ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[3]) 249ebf7d1f5SMaciej Fijalkowski EMIT2(0x41, 0x5F); /* pop r15 */ 250ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[2]) 251ebf7d1f5SMaciej Fijalkowski EMIT2(0x41, 0x5E); /* pop r14 */ 252ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[1]) 253ebf7d1f5SMaciej Fijalkowski EMIT2(0x41, 0x5D); /* pop r13 */ 254ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[0]) 255ebf7d1f5SMaciej Fijalkowski EMIT1(0x5B); /* pop rbx */ 256ebf7d1f5SMaciej Fijalkowski *pprog = prog; 257ebf7d1f5SMaciej Fijalkowski } 258b52f00e6SAlexei Starovoitov 259a2c7a983SIngo Molnar /* 260ebf7d1f5SMaciej Fijalkowski * Emit x86-64 prologue code for BPF program. 261ebf7d1f5SMaciej Fijalkowski * bpf_tail_call helper will skip the first X86_TAIL_CALL_OFFSET bytes 262ebf7d1f5SMaciej Fijalkowski * while jumping to another program 263b52f00e6SAlexei Starovoitov */ 264ebf7d1f5SMaciej Fijalkowski static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf, 265ebf7d1f5SMaciej Fijalkowski bool tail_call_reachable, bool is_subprog) 2660a14842fSEric Dumazet { 267b52f00e6SAlexei Starovoitov u8 *prog = *pprog; 2684b3da77bSDaniel Borkmann int cnt = X86_PATCH_SIZE; 2690a14842fSEric Dumazet 2709fd4a39dSAlexei Starovoitov /* BPF trampoline can be made to work without these nops, 2719fd4a39dSAlexei Starovoitov * but let's waste 5 bytes for now and optimize later 2729fd4a39dSAlexei Starovoitov */ 2739fd4a39dSAlexei Starovoitov memcpy(prog, ideal_nops[NOP_ATOMIC5], cnt); 2749fd4a39dSAlexei Starovoitov prog += cnt; 275ebf7d1f5SMaciej Fijalkowski if (!ebpf_from_cbpf) { 276ebf7d1f5SMaciej Fijalkowski if (tail_call_reachable && !is_subprog) 277ebf7d1f5SMaciej Fijalkowski EMIT2(0x31, 0xC0); /* xor eax, eax */ 278ebf7d1f5SMaciej Fijalkowski else 279ebf7d1f5SMaciej Fijalkowski EMIT2(0x66, 0x90); /* nop2 */ 280ebf7d1f5SMaciej Fijalkowski } 281fe8d9571SAlexei Starovoitov EMIT1(0x55); /* push rbp */ 282fe8d9571SAlexei Starovoitov EMIT3(0x48, 0x89, 0xE5); /* mov rbp, rsp */ 283fe8d9571SAlexei Starovoitov /* sub rsp, rounded_stack_depth */ 284fe8d9571SAlexei Starovoitov EMIT3_off32(0x48, 0x81, 0xEC, round_up(stack_depth, 8)); 285ebf7d1f5SMaciej Fijalkowski if (tail_call_reachable) 286ebf7d1f5SMaciej Fijalkowski EMIT1(0x50); /* push rax */ 287b52f00e6SAlexei Starovoitov *pprog = prog; 288b52f00e6SAlexei Starovoitov } 289b52f00e6SAlexei Starovoitov 290428d5df1SDaniel Borkmann static int emit_patch(u8 **pprog, void *func, void *ip, u8 opcode) 291428d5df1SDaniel Borkmann { 292428d5df1SDaniel Borkmann u8 *prog = *pprog; 293428d5df1SDaniel Borkmann int cnt = 0; 294428d5df1SDaniel Borkmann s64 offset; 295428d5df1SDaniel Borkmann 296428d5df1SDaniel Borkmann offset = func - (ip + X86_PATCH_SIZE); 297428d5df1SDaniel Borkmann if (!is_simm32(offset)) { 298428d5df1SDaniel Borkmann pr_err("Target call %p is out of range\n", func); 299428d5df1SDaniel Borkmann return -ERANGE; 300428d5df1SDaniel Borkmann } 301428d5df1SDaniel Borkmann EMIT1_off32(opcode, offset); 302428d5df1SDaniel Borkmann *pprog = prog; 303428d5df1SDaniel Borkmann return 0; 304428d5df1SDaniel Borkmann } 305428d5df1SDaniel Borkmann 306428d5df1SDaniel Borkmann static int emit_call(u8 **pprog, void *func, void *ip) 307428d5df1SDaniel Borkmann { 308428d5df1SDaniel Borkmann return emit_patch(pprog, func, ip, 0xE8); 309428d5df1SDaniel Borkmann } 310428d5df1SDaniel Borkmann 311428d5df1SDaniel Borkmann static int emit_jump(u8 **pprog, void *func, void *ip) 312428d5df1SDaniel Borkmann { 313428d5df1SDaniel Borkmann return emit_patch(pprog, func, ip, 0xE9); 314428d5df1SDaniel Borkmann } 315428d5df1SDaniel Borkmann 316428d5df1SDaniel Borkmann static int __bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, 317428d5df1SDaniel Borkmann void *old_addr, void *new_addr, 318428d5df1SDaniel Borkmann const bool text_live) 319428d5df1SDaniel Borkmann { 320428d5df1SDaniel Borkmann const u8 *nop_insn = ideal_nops[NOP_ATOMIC5]; 321b553a6ecSDaniel Borkmann u8 old_insn[X86_PATCH_SIZE]; 322b553a6ecSDaniel Borkmann u8 new_insn[X86_PATCH_SIZE]; 323428d5df1SDaniel Borkmann u8 *prog; 324428d5df1SDaniel Borkmann int ret; 325428d5df1SDaniel Borkmann 326428d5df1SDaniel Borkmann memcpy(old_insn, nop_insn, X86_PATCH_SIZE); 327b553a6ecSDaniel Borkmann if (old_addr) { 328428d5df1SDaniel Borkmann prog = old_insn; 329b553a6ecSDaniel Borkmann ret = t == BPF_MOD_CALL ? 330b553a6ecSDaniel Borkmann emit_call(&prog, old_addr, ip) : 331b553a6ecSDaniel Borkmann emit_jump(&prog, old_addr, ip); 332428d5df1SDaniel Borkmann if (ret) 333428d5df1SDaniel Borkmann return ret; 334428d5df1SDaniel Borkmann } 335b553a6ecSDaniel Borkmann 336428d5df1SDaniel Borkmann memcpy(new_insn, nop_insn, X86_PATCH_SIZE); 337b553a6ecSDaniel Borkmann if (new_addr) { 338b553a6ecSDaniel Borkmann prog = new_insn; 339b553a6ecSDaniel Borkmann ret = t == BPF_MOD_CALL ? 340b553a6ecSDaniel Borkmann emit_call(&prog, new_addr, ip) : 341b553a6ecSDaniel Borkmann emit_jump(&prog, new_addr, ip); 342428d5df1SDaniel Borkmann if (ret) 343428d5df1SDaniel Borkmann return ret; 344428d5df1SDaniel Borkmann } 345428d5df1SDaniel Borkmann 346428d5df1SDaniel Borkmann ret = -EBUSY; 347428d5df1SDaniel Borkmann mutex_lock(&text_mutex); 348428d5df1SDaniel Borkmann if (memcmp(ip, old_insn, X86_PATCH_SIZE)) 349428d5df1SDaniel Borkmann goto out; 350ebf7d1f5SMaciej Fijalkowski ret = 1; 351b553a6ecSDaniel Borkmann if (memcmp(ip, new_insn, X86_PATCH_SIZE)) { 352428d5df1SDaniel Borkmann if (text_live) 353428d5df1SDaniel Borkmann text_poke_bp(ip, new_insn, X86_PATCH_SIZE, NULL); 354428d5df1SDaniel Borkmann else 355428d5df1SDaniel Borkmann memcpy(ip, new_insn, X86_PATCH_SIZE); 356428d5df1SDaniel Borkmann ret = 0; 357ebf7d1f5SMaciej Fijalkowski } 358428d5df1SDaniel Borkmann out: 359428d5df1SDaniel Borkmann mutex_unlock(&text_mutex); 360428d5df1SDaniel Borkmann return ret; 361428d5df1SDaniel Borkmann } 362428d5df1SDaniel Borkmann 363428d5df1SDaniel Borkmann int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, 364428d5df1SDaniel Borkmann void *old_addr, void *new_addr) 365428d5df1SDaniel Borkmann { 366428d5df1SDaniel Borkmann if (!is_kernel_text((long)ip) && 367428d5df1SDaniel Borkmann !is_bpf_text_address((long)ip)) 368428d5df1SDaniel Borkmann /* BPF poking in modules is not supported */ 369428d5df1SDaniel Borkmann return -EINVAL; 370428d5df1SDaniel Borkmann 371428d5df1SDaniel Borkmann return __bpf_arch_text_poke(ip, t, old_addr, new_addr, true); 372428d5df1SDaniel Borkmann } 373428d5df1SDaniel Borkmann 374ebf7d1f5SMaciej Fijalkowski static int get_pop_bytes(bool *callee_regs_used) 375ebf7d1f5SMaciej Fijalkowski { 376ebf7d1f5SMaciej Fijalkowski int bytes = 0; 377ebf7d1f5SMaciej Fijalkowski 378ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[3]) 379ebf7d1f5SMaciej Fijalkowski bytes += 2; 380ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[2]) 381ebf7d1f5SMaciej Fijalkowski bytes += 2; 382ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[1]) 383ebf7d1f5SMaciej Fijalkowski bytes += 2; 384ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[0]) 385ebf7d1f5SMaciej Fijalkowski bytes += 1; 386ebf7d1f5SMaciej Fijalkowski 387ebf7d1f5SMaciej Fijalkowski return bytes; 388ebf7d1f5SMaciej Fijalkowski } 389ebf7d1f5SMaciej Fijalkowski 390a2c7a983SIngo Molnar /* 391a2c7a983SIngo Molnar * Generate the following code: 392a2c7a983SIngo Molnar * 393b52f00e6SAlexei Starovoitov * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... 394b52f00e6SAlexei Starovoitov * if (index >= array->map.max_entries) 395b52f00e6SAlexei Starovoitov * goto out; 396b52f00e6SAlexei Starovoitov * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) 397b52f00e6SAlexei Starovoitov * goto out; 3982a36f0b9SWang Nan * prog = array->ptrs[index]; 399b52f00e6SAlexei Starovoitov * if (prog == NULL) 400b52f00e6SAlexei Starovoitov * goto out; 401b52f00e6SAlexei Starovoitov * goto *(prog->bpf_func + prologue_size); 402b52f00e6SAlexei Starovoitov * out: 403b52f00e6SAlexei Starovoitov */ 404ebf7d1f5SMaciej Fijalkowski static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used, 405ebf7d1f5SMaciej Fijalkowski u32 stack_depth) 406b52f00e6SAlexei Starovoitov { 407ebf7d1f5SMaciej Fijalkowski int tcc_off = -4 - round_up(stack_depth, 8); 408b52f00e6SAlexei Starovoitov u8 *prog = *pprog; 409ebf7d1f5SMaciej Fijalkowski int pop_bytes = 0; 410ebf7d1f5SMaciej Fijalkowski int off1 = 49; 411ebf7d1f5SMaciej Fijalkowski int off2 = 38; 412ebf7d1f5SMaciej Fijalkowski int off3 = 16; 413b52f00e6SAlexei Starovoitov int cnt = 0; 414b52f00e6SAlexei Starovoitov 415ebf7d1f5SMaciej Fijalkowski /* count the additional bytes used for popping callee regs from stack 416ebf7d1f5SMaciej Fijalkowski * that need to be taken into account for each of the offsets that 417ebf7d1f5SMaciej Fijalkowski * are used for bailing out of the tail call 418ebf7d1f5SMaciej Fijalkowski */ 419ebf7d1f5SMaciej Fijalkowski pop_bytes = get_pop_bytes(callee_regs_used); 420ebf7d1f5SMaciej Fijalkowski off1 += pop_bytes; 421ebf7d1f5SMaciej Fijalkowski off2 += pop_bytes; 422ebf7d1f5SMaciej Fijalkowski off3 += pop_bytes; 423ebf7d1f5SMaciej Fijalkowski 424a2c7a983SIngo Molnar /* 425a2c7a983SIngo Molnar * rdi - pointer to ctx 426b52f00e6SAlexei Starovoitov * rsi - pointer to bpf_array 427b52f00e6SAlexei Starovoitov * rdx - index in bpf_array 428b52f00e6SAlexei Starovoitov */ 429b52f00e6SAlexei Starovoitov 430a2c7a983SIngo Molnar /* 431a2c7a983SIngo Molnar * if (index >= array->map.max_entries) 432b52f00e6SAlexei Starovoitov * goto out; 433b52f00e6SAlexei Starovoitov */ 43490caccddSAlexei Starovoitov EMIT2(0x89, 0xD2); /* mov edx, edx */ 43590caccddSAlexei Starovoitov EMIT3(0x39, 0x56, /* cmp dword ptr [rsi + 16], edx */ 436b52f00e6SAlexei Starovoitov offsetof(struct bpf_array, map.max_entries)); 437ebf7d1f5SMaciej Fijalkowski #define OFFSET1 (off1 + RETPOLINE_RCX_BPF_JIT_SIZE) /* Number of bytes to jump */ 438b52f00e6SAlexei Starovoitov EMIT2(X86_JBE, OFFSET1); /* jbe out */ 439b52f00e6SAlexei Starovoitov 440a2c7a983SIngo Molnar /* 441a2c7a983SIngo Molnar * if (tail_call_cnt > MAX_TAIL_CALL_CNT) 442b52f00e6SAlexei Starovoitov * goto out; 443b52f00e6SAlexei Starovoitov */ 444ebf7d1f5SMaciej Fijalkowski EMIT2_off32(0x8B, 0x85, tcc_off); /* mov eax, dword ptr [rbp - tcc_off] */ 445b52f00e6SAlexei Starovoitov EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ 446ebf7d1f5SMaciej Fijalkowski #define OFFSET2 (off2 + RETPOLINE_RCX_BPF_JIT_SIZE) 447b52f00e6SAlexei Starovoitov EMIT2(X86_JA, OFFSET2); /* ja out */ 448b52f00e6SAlexei Starovoitov EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ 449ebf7d1f5SMaciej Fijalkowski EMIT2_off32(0x89, 0x85, tcc_off); /* mov dword ptr [rbp - tcc_off], eax */ 450b52f00e6SAlexei Starovoitov 4512a36f0b9SWang Nan /* prog = array->ptrs[index]; */ 4520d4ddce3SMaciej Fijalkowski EMIT4_off32(0x48, 0x8B, 0x8C, 0xD6, /* mov rcx, [rsi + rdx * 8 + offsetof(...)] */ 4532a36f0b9SWang Nan offsetof(struct bpf_array, ptrs)); 454b52f00e6SAlexei Starovoitov 455a2c7a983SIngo Molnar /* 456a2c7a983SIngo Molnar * if (prog == NULL) 457b52f00e6SAlexei Starovoitov * goto out; 458b52f00e6SAlexei Starovoitov */ 4590d4ddce3SMaciej Fijalkowski EMIT3(0x48, 0x85, 0xC9); /* test rcx,rcx */ 460ebf7d1f5SMaciej Fijalkowski #define OFFSET3 (off3 + RETPOLINE_RCX_BPF_JIT_SIZE) 461b52f00e6SAlexei Starovoitov EMIT2(X86_JE, OFFSET3); /* je out */ 462b52f00e6SAlexei Starovoitov 463ebf7d1f5SMaciej Fijalkowski *pprog = prog; 464ebf7d1f5SMaciej Fijalkowski pop_callee_regs(pprog, callee_regs_used); 465ebf7d1f5SMaciej Fijalkowski prog = *pprog; 466ebf7d1f5SMaciej Fijalkowski 467ebf7d1f5SMaciej Fijalkowski EMIT1(0x58); /* pop rax */ 468ebf7d1f5SMaciej Fijalkowski EMIT3_off32(0x48, 0x81, 0xC4, /* add rsp, sd */ 469ebf7d1f5SMaciej Fijalkowski round_up(stack_depth, 8)); 470ebf7d1f5SMaciej Fijalkowski 471ebf7d1f5SMaciej Fijalkowski /* goto *(prog->bpf_func + X86_TAIL_CALL_OFFSET); */ 4720d4ddce3SMaciej Fijalkowski EMIT4(0x48, 0x8B, 0x49, /* mov rcx, qword ptr [rcx + 32] */ 473b52f00e6SAlexei Starovoitov offsetof(struct bpf_prog, bpf_func)); 474ebf7d1f5SMaciej Fijalkowski EMIT4(0x48, 0x83, 0xC1, /* add rcx, X86_TAIL_CALL_OFFSET */ 475ebf7d1f5SMaciej Fijalkowski X86_TAIL_CALL_OFFSET); 476a2c7a983SIngo Molnar /* 4770d4ddce3SMaciej Fijalkowski * Now we're ready to jump into next BPF program 478b52f00e6SAlexei Starovoitov * rdi == ctx (1st arg) 479ebf7d1f5SMaciej Fijalkowski * rcx == prog->bpf_func + X86_TAIL_CALL_OFFSET 480b52f00e6SAlexei Starovoitov */ 4810d4ddce3SMaciej Fijalkowski RETPOLINE_RCX_BPF_JIT(); 482b52f00e6SAlexei Starovoitov 483b52f00e6SAlexei Starovoitov /* out: */ 484b52f00e6SAlexei Starovoitov *pprog = prog; 485b52f00e6SAlexei Starovoitov } 486b52f00e6SAlexei Starovoitov 487428d5df1SDaniel Borkmann static void emit_bpf_tail_call_direct(struct bpf_jit_poke_descriptor *poke, 488ebf7d1f5SMaciej Fijalkowski u8 **pprog, int addr, u8 *image, 489ebf7d1f5SMaciej Fijalkowski bool *callee_regs_used, u32 stack_depth) 490428d5df1SDaniel Borkmann { 491ebf7d1f5SMaciej Fijalkowski int tcc_off = -4 - round_up(stack_depth, 8); 492428d5df1SDaniel Borkmann u8 *prog = *pprog; 493ebf7d1f5SMaciej Fijalkowski int pop_bytes = 0; 494ebf7d1f5SMaciej Fijalkowski int off1 = 27; 495ebf7d1f5SMaciej Fijalkowski int poke_off; 496428d5df1SDaniel Borkmann int cnt = 0; 497428d5df1SDaniel Borkmann 498ebf7d1f5SMaciej Fijalkowski /* count the additional bytes used for popping callee regs to stack 499ebf7d1f5SMaciej Fijalkowski * that need to be taken into account for jump offset that is used for 500ebf7d1f5SMaciej Fijalkowski * bailing out from of the tail call when limit is reached 501ebf7d1f5SMaciej Fijalkowski */ 502ebf7d1f5SMaciej Fijalkowski pop_bytes = get_pop_bytes(callee_regs_used); 503ebf7d1f5SMaciej Fijalkowski off1 += pop_bytes; 504ebf7d1f5SMaciej Fijalkowski 505ebf7d1f5SMaciej Fijalkowski /* 506ebf7d1f5SMaciej Fijalkowski * total bytes for: 507ebf7d1f5SMaciej Fijalkowski * - nop5/ jmpq $off 508ebf7d1f5SMaciej Fijalkowski * - pop callee regs 509ebf7d1f5SMaciej Fijalkowski * - sub rsp, $val 510ebf7d1f5SMaciej Fijalkowski * - pop rax 511ebf7d1f5SMaciej Fijalkowski */ 512ebf7d1f5SMaciej Fijalkowski poke_off = X86_PATCH_SIZE + pop_bytes + 7 + 1; 513ebf7d1f5SMaciej Fijalkowski 514428d5df1SDaniel Borkmann /* 515428d5df1SDaniel Borkmann * if (tail_call_cnt > MAX_TAIL_CALL_CNT) 516428d5df1SDaniel Borkmann * goto out; 517428d5df1SDaniel Borkmann */ 518ebf7d1f5SMaciej Fijalkowski EMIT2_off32(0x8B, 0x85, tcc_off); /* mov eax, dword ptr [rbp - tcc_off] */ 519428d5df1SDaniel Borkmann EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ 520ebf7d1f5SMaciej Fijalkowski EMIT2(X86_JA, off1); /* ja out */ 521428d5df1SDaniel Borkmann EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ 522ebf7d1f5SMaciej Fijalkowski EMIT2_off32(0x89, 0x85, tcc_off); /* mov dword ptr [rbp - tcc_off], eax */ 523428d5df1SDaniel Borkmann 524ebf7d1f5SMaciej Fijalkowski poke->tailcall_bypass = image + (addr - poke_off - X86_PATCH_SIZE); 525ebf7d1f5SMaciej Fijalkowski poke->adj_off = X86_TAIL_CALL_OFFSET; 526cf71b174SMaciej Fijalkowski poke->tailcall_target = image + (addr - X86_PATCH_SIZE); 527ebf7d1f5SMaciej Fijalkowski poke->bypass_addr = (u8 *)poke->tailcall_target + X86_PATCH_SIZE; 528ebf7d1f5SMaciej Fijalkowski 529ebf7d1f5SMaciej Fijalkowski emit_jump(&prog, (u8 *)poke->tailcall_target + X86_PATCH_SIZE, 530ebf7d1f5SMaciej Fijalkowski poke->tailcall_bypass); 531ebf7d1f5SMaciej Fijalkowski 532ebf7d1f5SMaciej Fijalkowski *pprog = prog; 533ebf7d1f5SMaciej Fijalkowski pop_callee_regs(pprog, callee_regs_used); 534ebf7d1f5SMaciej Fijalkowski prog = *pprog; 535ebf7d1f5SMaciej Fijalkowski EMIT1(0x58); /* pop rax */ 536ebf7d1f5SMaciej Fijalkowski EMIT3_off32(0x48, 0x81, 0xC4, round_up(stack_depth, 8)); 537428d5df1SDaniel Borkmann 538428d5df1SDaniel Borkmann memcpy(prog, ideal_nops[NOP_ATOMIC5], X86_PATCH_SIZE); 539428d5df1SDaniel Borkmann prog += X86_PATCH_SIZE; 540428d5df1SDaniel Borkmann /* out: */ 541428d5df1SDaniel Borkmann 542428d5df1SDaniel Borkmann *pprog = prog; 543428d5df1SDaniel Borkmann } 544428d5df1SDaniel Borkmann 545428d5df1SDaniel Borkmann static void bpf_tail_call_direct_fixup(struct bpf_prog *prog) 546428d5df1SDaniel Borkmann { 547428d5df1SDaniel Borkmann struct bpf_jit_poke_descriptor *poke; 548428d5df1SDaniel Borkmann struct bpf_array *array; 549428d5df1SDaniel Borkmann struct bpf_prog *target; 550428d5df1SDaniel Borkmann int i, ret; 551428d5df1SDaniel Borkmann 552428d5df1SDaniel Borkmann for (i = 0; i < prog->aux->size_poke_tab; i++) { 553428d5df1SDaniel Borkmann poke = &prog->aux->poke_tab[i]; 554cf71b174SMaciej Fijalkowski WARN_ON_ONCE(READ_ONCE(poke->tailcall_target_stable)); 555428d5df1SDaniel Borkmann 556428d5df1SDaniel Borkmann if (poke->reason != BPF_POKE_REASON_TAIL_CALL) 557428d5df1SDaniel Borkmann continue; 558428d5df1SDaniel Borkmann 559428d5df1SDaniel Borkmann array = container_of(poke->tail_call.map, struct bpf_array, map); 560428d5df1SDaniel Borkmann mutex_lock(&array->aux->poke_mutex); 561428d5df1SDaniel Borkmann target = array->ptrs[poke->tail_call.key]; 562428d5df1SDaniel Borkmann if (target) { 563428d5df1SDaniel Borkmann /* Plain memcpy is used when image is not live yet 564428d5df1SDaniel Borkmann * and still not locked as read-only. Once poke 565cf71b174SMaciej Fijalkowski * location is active (poke->tailcall_target_stable), 566cf71b174SMaciej Fijalkowski * any parallel bpf_arch_text_poke() might occur 567cf71b174SMaciej Fijalkowski * still on the read-write image until we finally 568cf71b174SMaciej Fijalkowski * locked it as read-only. Both modifications on 569cf71b174SMaciej Fijalkowski * the given image are under text_mutex to avoid 570cf71b174SMaciej Fijalkowski * interference. 571428d5df1SDaniel Borkmann */ 572cf71b174SMaciej Fijalkowski ret = __bpf_arch_text_poke(poke->tailcall_target, 573cf71b174SMaciej Fijalkowski BPF_MOD_JUMP, NULL, 574428d5df1SDaniel Borkmann (u8 *)target->bpf_func + 575428d5df1SDaniel Borkmann poke->adj_off, false); 576428d5df1SDaniel Borkmann BUG_ON(ret < 0); 577ebf7d1f5SMaciej Fijalkowski ret = __bpf_arch_text_poke(poke->tailcall_bypass, 578ebf7d1f5SMaciej Fijalkowski BPF_MOD_JUMP, 579ebf7d1f5SMaciej Fijalkowski (u8 *)poke->tailcall_target + 580ebf7d1f5SMaciej Fijalkowski X86_PATCH_SIZE, NULL, false); 581ebf7d1f5SMaciej Fijalkowski BUG_ON(ret < 0); 582428d5df1SDaniel Borkmann } 583cf71b174SMaciej Fijalkowski WRITE_ONCE(poke->tailcall_target_stable, true); 584428d5df1SDaniel Borkmann mutex_unlock(&array->aux->poke_mutex); 585428d5df1SDaniel Borkmann } 586428d5df1SDaniel Borkmann } 587428d5df1SDaniel Borkmann 5886fe8b9c1SDaniel Borkmann static void emit_mov_imm32(u8 **pprog, bool sign_propagate, 5896fe8b9c1SDaniel Borkmann u32 dst_reg, const u32 imm32) 5906fe8b9c1SDaniel Borkmann { 5916fe8b9c1SDaniel Borkmann u8 *prog = *pprog; 5926fe8b9c1SDaniel Borkmann u8 b1, b2, b3; 5936fe8b9c1SDaniel Borkmann int cnt = 0; 5946fe8b9c1SDaniel Borkmann 595a2c7a983SIngo Molnar /* 596a2c7a983SIngo Molnar * Optimization: if imm32 is positive, use 'mov %eax, imm32' 5976fe8b9c1SDaniel Borkmann * (which zero-extends imm32) to save 2 bytes. 5986fe8b9c1SDaniel Borkmann */ 5996fe8b9c1SDaniel Borkmann if (sign_propagate && (s32)imm32 < 0) { 6006fe8b9c1SDaniel Borkmann /* 'mov %rax, imm32' sign extends imm32 */ 6016fe8b9c1SDaniel Borkmann b1 = add_1mod(0x48, dst_reg); 6026fe8b9c1SDaniel Borkmann b2 = 0xC7; 6036fe8b9c1SDaniel Borkmann b3 = 0xC0; 6046fe8b9c1SDaniel Borkmann EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); 6056fe8b9c1SDaniel Borkmann goto done; 6066fe8b9c1SDaniel Borkmann } 6076fe8b9c1SDaniel Borkmann 608a2c7a983SIngo Molnar /* 609a2c7a983SIngo Molnar * Optimization: if imm32 is zero, use 'xor %eax, %eax' 6106fe8b9c1SDaniel Borkmann * to save 3 bytes. 6116fe8b9c1SDaniel Borkmann */ 6126fe8b9c1SDaniel Borkmann if (imm32 == 0) { 6136fe8b9c1SDaniel Borkmann if (is_ereg(dst_reg)) 6146fe8b9c1SDaniel Borkmann EMIT1(add_2mod(0x40, dst_reg, dst_reg)); 6156fe8b9c1SDaniel Borkmann b2 = 0x31; /* xor */ 6166fe8b9c1SDaniel Borkmann b3 = 0xC0; 6176fe8b9c1SDaniel Borkmann EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); 6186fe8b9c1SDaniel Borkmann goto done; 6196fe8b9c1SDaniel Borkmann } 6206fe8b9c1SDaniel Borkmann 6216fe8b9c1SDaniel Borkmann /* mov %eax, imm32 */ 6226fe8b9c1SDaniel Borkmann if (is_ereg(dst_reg)) 6236fe8b9c1SDaniel Borkmann EMIT1(add_1mod(0x40, dst_reg)); 6246fe8b9c1SDaniel Borkmann EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); 6256fe8b9c1SDaniel Borkmann done: 6266fe8b9c1SDaniel Borkmann *pprog = prog; 6276fe8b9c1SDaniel Borkmann } 6286fe8b9c1SDaniel Borkmann 6296fe8b9c1SDaniel Borkmann static void emit_mov_imm64(u8 **pprog, u32 dst_reg, 6306fe8b9c1SDaniel Borkmann const u32 imm32_hi, const u32 imm32_lo) 6316fe8b9c1SDaniel Borkmann { 6326fe8b9c1SDaniel Borkmann u8 *prog = *pprog; 6336fe8b9c1SDaniel Borkmann int cnt = 0; 6346fe8b9c1SDaniel Borkmann 6356fe8b9c1SDaniel Borkmann if (is_uimm32(((u64)imm32_hi << 32) | (u32)imm32_lo)) { 636a2c7a983SIngo Molnar /* 637a2c7a983SIngo Molnar * For emitting plain u32, where sign bit must not be 6386fe8b9c1SDaniel Borkmann * propagated LLVM tends to load imm64 over mov32 6396fe8b9c1SDaniel Borkmann * directly, so save couple of bytes by just doing 6406fe8b9c1SDaniel Borkmann * 'mov %eax, imm32' instead. 6416fe8b9c1SDaniel Borkmann */ 6426fe8b9c1SDaniel Borkmann emit_mov_imm32(&prog, false, dst_reg, imm32_lo); 6436fe8b9c1SDaniel Borkmann } else { 6446fe8b9c1SDaniel Borkmann /* movabsq %rax, imm64 */ 6456fe8b9c1SDaniel Borkmann EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); 6466fe8b9c1SDaniel Borkmann EMIT(imm32_lo, 4); 6476fe8b9c1SDaniel Borkmann EMIT(imm32_hi, 4); 6486fe8b9c1SDaniel Borkmann } 6496fe8b9c1SDaniel Borkmann 6506fe8b9c1SDaniel Borkmann *pprog = prog; 6516fe8b9c1SDaniel Borkmann } 6526fe8b9c1SDaniel Borkmann 6534c38e2f3SDaniel Borkmann static void emit_mov_reg(u8 **pprog, bool is64, u32 dst_reg, u32 src_reg) 6544c38e2f3SDaniel Borkmann { 6554c38e2f3SDaniel Borkmann u8 *prog = *pprog; 6564c38e2f3SDaniel Borkmann int cnt = 0; 6574c38e2f3SDaniel Borkmann 6584c38e2f3SDaniel Borkmann if (is64) { 6594c38e2f3SDaniel Borkmann /* mov dst, src */ 6604c38e2f3SDaniel Borkmann EMIT_mov(dst_reg, src_reg); 6614c38e2f3SDaniel Borkmann } else { 6624c38e2f3SDaniel Borkmann /* mov32 dst, src */ 6634c38e2f3SDaniel Borkmann if (is_ereg(dst_reg) || is_ereg(src_reg)) 6644c38e2f3SDaniel Borkmann EMIT1(add_2mod(0x40, dst_reg, src_reg)); 6654c38e2f3SDaniel Borkmann EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); 6664c38e2f3SDaniel Borkmann } 6674c38e2f3SDaniel Borkmann 6684c38e2f3SDaniel Borkmann *pprog = prog; 6694c38e2f3SDaniel Borkmann } 6704c38e2f3SDaniel Borkmann 6713b2744e6SAlexei Starovoitov /* LDX: dst_reg = *(u8*)(src_reg + off) */ 6723b2744e6SAlexei Starovoitov static void emit_ldx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) 6733b2744e6SAlexei Starovoitov { 6743b2744e6SAlexei Starovoitov u8 *prog = *pprog; 6753b2744e6SAlexei Starovoitov int cnt = 0; 6763b2744e6SAlexei Starovoitov 6773b2744e6SAlexei Starovoitov switch (size) { 6783b2744e6SAlexei Starovoitov case BPF_B: 6793b2744e6SAlexei Starovoitov /* Emit 'movzx rax, byte ptr [rax + off]' */ 6803b2744e6SAlexei Starovoitov EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); 6813b2744e6SAlexei Starovoitov break; 6823b2744e6SAlexei Starovoitov case BPF_H: 6833b2744e6SAlexei Starovoitov /* Emit 'movzx rax, word ptr [rax + off]' */ 6843b2744e6SAlexei Starovoitov EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); 6853b2744e6SAlexei Starovoitov break; 6863b2744e6SAlexei Starovoitov case BPF_W: 6873b2744e6SAlexei Starovoitov /* Emit 'mov eax, dword ptr [rax+0x14]' */ 6883b2744e6SAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 6893b2744e6SAlexei Starovoitov EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); 6903b2744e6SAlexei Starovoitov else 6913b2744e6SAlexei Starovoitov EMIT1(0x8B); 6923b2744e6SAlexei Starovoitov break; 6933b2744e6SAlexei Starovoitov case BPF_DW: 6943b2744e6SAlexei Starovoitov /* Emit 'mov rax, qword ptr [rax+0x14]' */ 6953b2744e6SAlexei Starovoitov EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); 6963b2744e6SAlexei Starovoitov break; 6973b2744e6SAlexei Starovoitov } 6983b2744e6SAlexei Starovoitov /* 6993b2744e6SAlexei Starovoitov * If insn->off == 0 we can save one extra byte, but 7003b2744e6SAlexei Starovoitov * special case of x86 R13 which always needs an offset 7013b2744e6SAlexei Starovoitov * is not worth the hassle 7023b2744e6SAlexei Starovoitov */ 7033b2744e6SAlexei Starovoitov if (is_imm8(off)) 7043b2744e6SAlexei Starovoitov EMIT2(add_2reg(0x40, src_reg, dst_reg), off); 7053b2744e6SAlexei Starovoitov else 7063b2744e6SAlexei Starovoitov EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), off); 7073b2744e6SAlexei Starovoitov *pprog = prog; 7083b2744e6SAlexei Starovoitov } 7093b2744e6SAlexei Starovoitov 7103b2744e6SAlexei Starovoitov /* STX: *(u8*)(dst_reg + off) = src_reg */ 7113b2744e6SAlexei Starovoitov static void emit_stx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) 7123b2744e6SAlexei Starovoitov { 7133b2744e6SAlexei Starovoitov u8 *prog = *pprog; 7143b2744e6SAlexei Starovoitov int cnt = 0; 7153b2744e6SAlexei Starovoitov 7163b2744e6SAlexei Starovoitov switch (size) { 7173b2744e6SAlexei Starovoitov case BPF_B: 7183b2744e6SAlexei Starovoitov /* Emit 'mov byte ptr [rax + off], al' */ 719aee194b1SLuke Nelson if (is_ereg(dst_reg) || is_ereg_8l(src_reg)) 720aee194b1SLuke Nelson /* Add extra byte for eregs or SIL,DIL,BPL in src_reg */ 7213b2744e6SAlexei Starovoitov EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); 7223b2744e6SAlexei Starovoitov else 7233b2744e6SAlexei Starovoitov EMIT1(0x88); 7243b2744e6SAlexei Starovoitov break; 7253b2744e6SAlexei Starovoitov case BPF_H: 7263b2744e6SAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 7273b2744e6SAlexei Starovoitov EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); 7283b2744e6SAlexei Starovoitov else 7293b2744e6SAlexei Starovoitov EMIT2(0x66, 0x89); 7303b2744e6SAlexei Starovoitov break; 7313b2744e6SAlexei Starovoitov case BPF_W: 7323b2744e6SAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 7333b2744e6SAlexei Starovoitov EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); 7343b2744e6SAlexei Starovoitov else 7353b2744e6SAlexei Starovoitov EMIT1(0x89); 7363b2744e6SAlexei Starovoitov break; 7373b2744e6SAlexei Starovoitov case BPF_DW: 7383b2744e6SAlexei Starovoitov EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); 7393b2744e6SAlexei Starovoitov break; 7403b2744e6SAlexei Starovoitov } 7413b2744e6SAlexei Starovoitov if (is_imm8(off)) 7423b2744e6SAlexei Starovoitov EMIT2(add_2reg(0x40, dst_reg, src_reg), off); 7433b2744e6SAlexei Starovoitov else 7443b2744e6SAlexei Starovoitov EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), off); 7453b2744e6SAlexei Starovoitov *pprog = prog; 7463b2744e6SAlexei Starovoitov } 7473b2744e6SAlexei Starovoitov 7483dec541bSAlexei Starovoitov static bool ex_handler_bpf(const struct exception_table_entry *x, 7493dec541bSAlexei Starovoitov struct pt_regs *regs, int trapnr, 7503dec541bSAlexei Starovoitov unsigned long error_code, unsigned long fault_addr) 7513dec541bSAlexei Starovoitov { 7523dec541bSAlexei Starovoitov u32 reg = x->fixup >> 8; 7533dec541bSAlexei Starovoitov 7543dec541bSAlexei Starovoitov /* jump over faulting load and clear dest register */ 7553dec541bSAlexei Starovoitov *(unsigned long *)((void *)regs + reg) = 0; 7563dec541bSAlexei Starovoitov regs->ip += x->fixup & 0xff; 7573dec541bSAlexei Starovoitov return true; 7583dec541bSAlexei Starovoitov } 7593dec541bSAlexei Starovoitov 760ebf7d1f5SMaciej Fijalkowski static void detect_reg_usage(struct bpf_insn *insn, int insn_cnt, 761ebf7d1f5SMaciej Fijalkowski bool *regs_used, bool *tail_call_seen) 762ebf7d1f5SMaciej Fijalkowski { 763ebf7d1f5SMaciej Fijalkowski int i; 764ebf7d1f5SMaciej Fijalkowski 765ebf7d1f5SMaciej Fijalkowski for (i = 1; i <= insn_cnt; i++, insn++) { 766ebf7d1f5SMaciej Fijalkowski if (insn->code == (BPF_JMP | BPF_TAIL_CALL)) 767ebf7d1f5SMaciej Fijalkowski *tail_call_seen = true; 768ebf7d1f5SMaciej Fijalkowski if (insn->dst_reg == BPF_REG_6 || insn->src_reg == BPF_REG_6) 769ebf7d1f5SMaciej Fijalkowski regs_used[0] = true; 770ebf7d1f5SMaciej Fijalkowski if (insn->dst_reg == BPF_REG_7 || insn->src_reg == BPF_REG_7) 771ebf7d1f5SMaciej Fijalkowski regs_used[1] = true; 772ebf7d1f5SMaciej Fijalkowski if (insn->dst_reg == BPF_REG_8 || insn->src_reg == BPF_REG_8) 773ebf7d1f5SMaciej Fijalkowski regs_used[2] = true; 774ebf7d1f5SMaciej Fijalkowski if (insn->dst_reg == BPF_REG_9 || insn->src_reg == BPF_REG_9) 775ebf7d1f5SMaciej Fijalkowski regs_used[3] = true; 776ebf7d1f5SMaciej Fijalkowski } 777ebf7d1f5SMaciej Fijalkowski } 778ebf7d1f5SMaciej Fijalkowski 779b52f00e6SAlexei Starovoitov static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, 780b52f00e6SAlexei Starovoitov int oldproglen, struct jit_context *ctx) 781b52f00e6SAlexei Starovoitov { 782ebf7d1f5SMaciej Fijalkowski bool tail_call_reachable = bpf_prog->aux->tail_call_reachable; 783b52f00e6SAlexei Starovoitov struct bpf_insn *insn = bpf_prog->insnsi; 784ebf7d1f5SMaciej Fijalkowski bool callee_regs_used[4] = {}; 785b52f00e6SAlexei Starovoitov int insn_cnt = bpf_prog->len; 786ebf7d1f5SMaciej Fijalkowski bool tail_call_seen = false; 787b52f00e6SAlexei Starovoitov bool seen_exit = false; 788b52f00e6SAlexei Starovoitov u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; 7893dec541bSAlexei Starovoitov int i, cnt = 0, excnt = 0; 790b52f00e6SAlexei Starovoitov int proglen = 0; 791b52f00e6SAlexei Starovoitov u8 *prog = temp; 792b52f00e6SAlexei Starovoitov 793ebf7d1f5SMaciej Fijalkowski detect_reg_usage(insn, insn_cnt, callee_regs_used, 794ebf7d1f5SMaciej Fijalkowski &tail_call_seen); 795ebf7d1f5SMaciej Fijalkowski 796ebf7d1f5SMaciej Fijalkowski /* tail call's presence in current prog implies it is reachable */ 797ebf7d1f5SMaciej Fijalkowski tail_call_reachable |= tail_call_seen; 798ebf7d1f5SMaciej Fijalkowski 79908691752SDaniel Borkmann emit_prologue(&prog, bpf_prog->aux->stack_depth, 800ebf7d1f5SMaciej Fijalkowski bpf_prog_was_classic(bpf_prog), tail_call_reachable, 801ebf7d1f5SMaciej Fijalkowski bpf_prog->aux->func_idx != 0); 802ebf7d1f5SMaciej Fijalkowski push_callee_regs(&prog, callee_regs_used); 8037c2e988fSAlexei Starovoitov addrs[0] = prog - temp; 804b52f00e6SAlexei Starovoitov 8057c2e988fSAlexei Starovoitov for (i = 1; i <= insn_cnt; i++, insn++) { 806e430f34eSAlexei Starovoitov const s32 imm32 = insn->imm; 807e430f34eSAlexei Starovoitov u32 dst_reg = insn->dst_reg; 808e430f34eSAlexei Starovoitov u32 src_reg = insn->src_reg; 8096fe8b9c1SDaniel Borkmann u8 b2 = 0, b3 = 0; 81062258278SAlexei Starovoitov s64 jmp_offset; 81162258278SAlexei Starovoitov u8 jmp_cond; 81262258278SAlexei Starovoitov int ilen; 81362258278SAlexei Starovoitov u8 *func; 81462258278SAlexei Starovoitov 81562258278SAlexei Starovoitov switch (insn->code) { 81662258278SAlexei Starovoitov /* ALU */ 81762258278SAlexei Starovoitov case BPF_ALU | BPF_ADD | BPF_X: 81862258278SAlexei Starovoitov case BPF_ALU | BPF_SUB | BPF_X: 81962258278SAlexei Starovoitov case BPF_ALU | BPF_AND | BPF_X: 82062258278SAlexei Starovoitov case BPF_ALU | BPF_OR | BPF_X: 82162258278SAlexei Starovoitov case BPF_ALU | BPF_XOR | BPF_X: 82262258278SAlexei Starovoitov case BPF_ALU64 | BPF_ADD | BPF_X: 82362258278SAlexei Starovoitov case BPF_ALU64 | BPF_SUB | BPF_X: 82462258278SAlexei Starovoitov case BPF_ALU64 | BPF_AND | BPF_X: 82562258278SAlexei Starovoitov case BPF_ALU64 | BPF_OR | BPF_X: 82662258278SAlexei Starovoitov case BPF_ALU64 | BPF_XOR | BPF_X: 82762258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 82862258278SAlexei Starovoitov case BPF_ADD: b2 = 0x01; break; 82962258278SAlexei Starovoitov case BPF_SUB: b2 = 0x29; break; 83062258278SAlexei Starovoitov case BPF_AND: b2 = 0x21; break; 83162258278SAlexei Starovoitov case BPF_OR: b2 = 0x09; break; 83262258278SAlexei Starovoitov case BPF_XOR: b2 = 0x31; break; 83362258278SAlexei Starovoitov } 83462258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 835e430f34eSAlexei Starovoitov EMIT1(add_2mod(0x48, dst_reg, src_reg)); 836e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg) || is_ereg(src_reg)) 837e430f34eSAlexei Starovoitov EMIT1(add_2mod(0x40, dst_reg, src_reg)); 838e430f34eSAlexei Starovoitov EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); 8390a14842fSEric Dumazet break; 84062258278SAlexei Starovoitov 84162258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOV | BPF_X: 84262258278SAlexei Starovoitov case BPF_ALU | BPF_MOV | BPF_X: 8434c38e2f3SDaniel Borkmann emit_mov_reg(&prog, 8444c38e2f3SDaniel Borkmann BPF_CLASS(insn->code) == BPF_ALU64, 8454c38e2f3SDaniel Borkmann dst_reg, src_reg); 84662258278SAlexei Starovoitov break; 84762258278SAlexei Starovoitov 848e430f34eSAlexei Starovoitov /* neg dst */ 84962258278SAlexei Starovoitov case BPF_ALU | BPF_NEG: 85062258278SAlexei Starovoitov case BPF_ALU64 | BPF_NEG: 85162258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 852e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 853e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg)) 854e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 855e430f34eSAlexei Starovoitov EMIT2(0xF7, add_1reg(0xD8, dst_reg)); 85662258278SAlexei Starovoitov break; 85762258278SAlexei Starovoitov 85862258278SAlexei Starovoitov case BPF_ALU | BPF_ADD | BPF_K: 85962258278SAlexei Starovoitov case BPF_ALU | BPF_SUB | BPF_K: 86062258278SAlexei Starovoitov case BPF_ALU | BPF_AND | BPF_K: 86162258278SAlexei Starovoitov case BPF_ALU | BPF_OR | BPF_K: 86262258278SAlexei Starovoitov case BPF_ALU | BPF_XOR | BPF_K: 86362258278SAlexei Starovoitov case BPF_ALU64 | BPF_ADD | BPF_K: 86462258278SAlexei Starovoitov case BPF_ALU64 | BPF_SUB | BPF_K: 86562258278SAlexei Starovoitov case BPF_ALU64 | BPF_AND | BPF_K: 86662258278SAlexei Starovoitov case BPF_ALU64 | BPF_OR | BPF_K: 86762258278SAlexei Starovoitov case BPF_ALU64 | BPF_XOR | BPF_K: 86862258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 869e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 870e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg)) 871e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 87262258278SAlexei Starovoitov 873a2c7a983SIngo Molnar /* 874a2c7a983SIngo Molnar * b3 holds 'normal' opcode, b2 short form only valid 875de0a444dSDaniel Borkmann * in case dst is eax/rax. 876de0a444dSDaniel Borkmann */ 87762258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 878de0a444dSDaniel Borkmann case BPF_ADD: 879de0a444dSDaniel Borkmann b3 = 0xC0; 880de0a444dSDaniel Borkmann b2 = 0x05; 881de0a444dSDaniel Borkmann break; 882de0a444dSDaniel Borkmann case BPF_SUB: 883de0a444dSDaniel Borkmann b3 = 0xE8; 884de0a444dSDaniel Borkmann b2 = 0x2D; 885de0a444dSDaniel Borkmann break; 886de0a444dSDaniel Borkmann case BPF_AND: 887de0a444dSDaniel Borkmann b3 = 0xE0; 888de0a444dSDaniel Borkmann b2 = 0x25; 889de0a444dSDaniel Borkmann break; 890de0a444dSDaniel Borkmann case BPF_OR: 891de0a444dSDaniel Borkmann b3 = 0xC8; 892de0a444dSDaniel Borkmann b2 = 0x0D; 893de0a444dSDaniel Borkmann break; 894de0a444dSDaniel Borkmann case BPF_XOR: 895de0a444dSDaniel Borkmann b3 = 0xF0; 896de0a444dSDaniel Borkmann b2 = 0x35; 897de0a444dSDaniel Borkmann break; 89862258278SAlexei Starovoitov } 89962258278SAlexei Starovoitov 900e430f34eSAlexei Starovoitov if (is_imm8(imm32)) 901e430f34eSAlexei Starovoitov EMIT3(0x83, add_1reg(b3, dst_reg), imm32); 902de0a444dSDaniel Borkmann else if (is_axreg(dst_reg)) 903de0a444dSDaniel Borkmann EMIT1_off32(b2, imm32); 90462258278SAlexei Starovoitov else 905e430f34eSAlexei Starovoitov EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); 90662258278SAlexei Starovoitov break; 90762258278SAlexei Starovoitov 90862258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOV | BPF_K: 90962258278SAlexei Starovoitov case BPF_ALU | BPF_MOV | BPF_K: 9106fe8b9c1SDaniel Borkmann emit_mov_imm32(&prog, BPF_CLASS(insn->code) == BPF_ALU64, 9116fe8b9c1SDaniel Borkmann dst_reg, imm32); 91262258278SAlexei Starovoitov break; 91362258278SAlexei Starovoitov 91402ab695bSAlexei Starovoitov case BPF_LD | BPF_IMM | BPF_DW: 9156fe8b9c1SDaniel Borkmann emit_mov_imm64(&prog, dst_reg, insn[1].imm, insn[0].imm); 91602ab695bSAlexei Starovoitov insn++; 91702ab695bSAlexei Starovoitov i++; 91802ab695bSAlexei Starovoitov break; 91902ab695bSAlexei Starovoitov 920e430f34eSAlexei Starovoitov /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ 92162258278SAlexei Starovoitov case BPF_ALU | BPF_MOD | BPF_X: 92262258278SAlexei Starovoitov case BPF_ALU | BPF_DIV | BPF_X: 92362258278SAlexei Starovoitov case BPF_ALU | BPF_MOD | BPF_K: 92462258278SAlexei Starovoitov case BPF_ALU | BPF_DIV | BPF_K: 92562258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOD | BPF_X: 92662258278SAlexei Starovoitov case BPF_ALU64 | BPF_DIV | BPF_X: 92762258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOD | BPF_K: 92862258278SAlexei Starovoitov case BPF_ALU64 | BPF_DIV | BPF_K: 92962258278SAlexei Starovoitov EMIT1(0x50); /* push rax */ 93062258278SAlexei Starovoitov EMIT1(0x52); /* push rdx */ 93162258278SAlexei Starovoitov 93262258278SAlexei Starovoitov if (BPF_SRC(insn->code) == BPF_X) 933e430f34eSAlexei Starovoitov /* mov r11, src_reg */ 934e430f34eSAlexei Starovoitov EMIT_mov(AUX_REG, src_reg); 93562258278SAlexei Starovoitov else 936e430f34eSAlexei Starovoitov /* mov r11, imm32 */ 937e430f34eSAlexei Starovoitov EMIT3_off32(0x49, 0xC7, 0xC3, imm32); 93862258278SAlexei Starovoitov 939e430f34eSAlexei Starovoitov /* mov rax, dst_reg */ 940e430f34eSAlexei Starovoitov EMIT_mov(BPF_REG_0, dst_reg); 94162258278SAlexei Starovoitov 942a2c7a983SIngo Molnar /* 943a2c7a983SIngo Molnar * xor edx, edx 94462258278SAlexei Starovoitov * equivalent to 'xor rdx, rdx', but one byte less 94562258278SAlexei Starovoitov */ 94662258278SAlexei Starovoitov EMIT2(0x31, 0xd2); 94762258278SAlexei Starovoitov 94862258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 94962258278SAlexei Starovoitov /* div r11 */ 95062258278SAlexei Starovoitov EMIT3(0x49, 0xF7, 0xF3); 95162258278SAlexei Starovoitov else 95262258278SAlexei Starovoitov /* div r11d */ 95362258278SAlexei Starovoitov EMIT3(0x41, 0xF7, 0xF3); 95462258278SAlexei Starovoitov 95562258278SAlexei Starovoitov if (BPF_OP(insn->code) == BPF_MOD) 95662258278SAlexei Starovoitov /* mov r11, rdx */ 95762258278SAlexei Starovoitov EMIT3(0x49, 0x89, 0xD3); 95862258278SAlexei Starovoitov else 95962258278SAlexei Starovoitov /* mov r11, rax */ 96062258278SAlexei Starovoitov EMIT3(0x49, 0x89, 0xC3); 96162258278SAlexei Starovoitov 96262258278SAlexei Starovoitov EMIT1(0x5A); /* pop rdx */ 96362258278SAlexei Starovoitov EMIT1(0x58); /* pop rax */ 96462258278SAlexei Starovoitov 965e430f34eSAlexei Starovoitov /* mov dst_reg, r11 */ 966e430f34eSAlexei Starovoitov EMIT_mov(dst_reg, AUX_REG); 96762258278SAlexei Starovoitov break; 96862258278SAlexei Starovoitov 96962258278SAlexei Starovoitov case BPF_ALU | BPF_MUL | BPF_K: 97062258278SAlexei Starovoitov case BPF_ALU | BPF_MUL | BPF_X: 97162258278SAlexei Starovoitov case BPF_ALU64 | BPF_MUL | BPF_K: 97262258278SAlexei Starovoitov case BPF_ALU64 | BPF_MUL | BPF_X: 9734c38e2f3SDaniel Borkmann { 9744c38e2f3SDaniel Borkmann bool is64 = BPF_CLASS(insn->code) == BPF_ALU64; 9754c38e2f3SDaniel Borkmann 976d806a0cfSDaniel Borkmann if (dst_reg != BPF_REG_0) 97762258278SAlexei Starovoitov EMIT1(0x50); /* push rax */ 978d806a0cfSDaniel Borkmann if (dst_reg != BPF_REG_3) 97962258278SAlexei Starovoitov EMIT1(0x52); /* push rdx */ 98062258278SAlexei Starovoitov 981e430f34eSAlexei Starovoitov /* mov r11, dst_reg */ 982e430f34eSAlexei Starovoitov EMIT_mov(AUX_REG, dst_reg); 98362258278SAlexei Starovoitov 98462258278SAlexei Starovoitov if (BPF_SRC(insn->code) == BPF_X) 9854c38e2f3SDaniel Borkmann emit_mov_reg(&prog, is64, BPF_REG_0, src_reg); 98662258278SAlexei Starovoitov else 9874c38e2f3SDaniel Borkmann emit_mov_imm32(&prog, is64, BPF_REG_0, imm32); 98862258278SAlexei Starovoitov 9894c38e2f3SDaniel Borkmann if (is64) 99062258278SAlexei Starovoitov EMIT1(add_1mod(0x48, AUX_REG)); 99162258278SAlexei Starovoitov else if (is_ereg(AUX_REG)) 99262258278SAlexei Starovoitov EMIT1(add_1mod(0x40, AUX_REG)); 99362258278SAlexei Starovoitov /* mul(q) r11 */ 99462258278SAlexei Starovoitov EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); 99562258278SAlexei Starovoitov 996d806a0cfSDaniel Borkmann if (dst_reg != BPF_REG_3) 99762258278SAlexei Starovoitov EMIT1(0x5A); /* pop rdx */ 998d806a0cfSDaniel Borkmann if (dst_reg != BPF_REG_0) { 999d806a0cfSDaniel Borkmann /* mov dst_reg, rax */ 1000d806a0cfSDaniel Borkmann EMIT_mov(dst_reg, BPF_REG_0); 100162258278SAlexei Starovoitov EMIT1(0x58); /* pop rax */ 1002d806a0cfSDaniel Borkmann } 100362258278SAlexei Starovoitov break; 10044c38e2f3SDaniel Borkmann } 1005a2c7a983SIngo Molnar /* Shifts */ 100662258278SAlexei Starovoitov case BPF_ALU | BPF_LSH | BPF_K: 100762258278SAlexei Starovoitov case BPF_ALU | BPF_RSH | BPF_K: 100862258278SAlexei Starovoitov case BPF_ALU | BPF_ARSH | BPF_K: 100962258278SAlexei Starovoitov case BPF_ALU64 | BPF_LSH | BPF_K: 101062258278SAlexei Starovoitov case BPF_ALU64 | BPF_RSH | BPF_K: 101162258278SAlexei Starovoitov case BPF_ALU64 | BPF_ARSH | BPF_K: 101262258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 1013e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 1014e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg)) 1015e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 101662258278SAlexei Starovoitov 101762258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 101862258278SAlexei Starovoitov case BPF_LSH: b3 = 0xE0; break; 101962258278SAlexei Starovoitov case BPF_RSH: b3 = 0xE8; break; 102062258278SAlexei Starovoitov case BPF_ARSH: b3 = 0xF8; break; 102162258278SAlexei Starovoitov } 102288e69a1fSDaniel Borkmann 102388e69a1fSDaniel Borkmann if (imm32 == 1) 102488e69a1fSDaniel Borkmann EMIT2(0xD1, add_1reg(b3, dst_reg)); 102588e69a1fSDaniel Borkmann else 1026e430f34eSAlexei Starovoitov EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); 102762258278SAlexei Starovoitov break; 102862258278SAlexei Starovoitov 102972b603eeSAlexei Starovoitov case BPF_ALU | BPF_LSH | BPF_X: 103072b603eeSAlexei Starovoitov case BPF_ALU | BPF_RSH | BPF_X: 103172b603eeSAlexei Starovoitov case BPF_ALU | BPF_ARSH | BPF_X: 103272b603eeSAlexei Starovoitov case BPF_ALU64 | BPF_LSH | BPF_X: 103372b603eeSAlexei Starovoitov case BPF_ALU64 | BPF_RSH | BPF_X: 103472b603eeSAlexei Starovoitov case BPF_ALU64 | BPF_ARSH | BPF_X: 103572b603eeSAlexei Starovoitov 1036a2c7a983SIngo Molnar /* Check for bad case when dst_reg == rcx */ 103772b603eeSAlexei Starovoitov if (dst_reg == BPF_REG_4) { 103872b603eeSAlexei Starovoitov /* mov r11, dst_reg */ 103972b603eeSAlexei Starovoitov EMIT_mov(AUX_REG, dst_reg); 104072b603eeSAlexei Starovoitov dst_reg = AUX_REG; 104172b603eeSAlexei Starovoitov } 104272b603eeSAlexei Starovoitov 104372b603eeSAlexei Starovoitov if (src_reg != BPF_REG_4) { /* common case */ 104472b603eeSAlexei Starovoitov EMIT1(0x51); /* push rcx */ 104572b603eeSAlexei Starovoitov 104672b603eeSAlexei Starovoitov /* mov rcx, src_reg */ 104772b603eeSAlexei Starovoitov EMIT_mov(BPF_REG_4, src_reg); 104872b603eeSAlexei Starovoitov } 104972b603eeSAlexei Starovoitov 105072b603eeSAlexei Starovoitov /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ 105172b603eeSAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 105272b603eeSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 105372b603eeSAlexei Starovoitov else if (is_ereg(dst_reg)) 105472b603eeSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 105572b603eeSAlexei Starovoitov 105672b603eeSAlexei Starovoitov switch (BPF_OP(insn->code)) { 105772b603eeSAlexei Starovoitov case BPF_LSH: b3 = 0xE0; break; 105872b603eeSAlexei Starovoitov case BPF_RSH: b3 = 0xE8; break; 105972b603eeSAlexei Starovoitov case BPF_ARSH: b3 = 0xF8; break; 106072b603eeSAlexei Starovoitov } 106172b603eeSAlexei Starovoitov EMIT2(0xD3, add_1reg(b3, dst_reg)); 106272b603eeSAlexei Starovoitov 106372b603eeSAlexei Starovoitov if (src_reg != BPF_REG_4) 106472b603eeSAlexei Starovoitov EMIT1(0x59); /* pop rcx */ 106572b603eeSAlexei Starovoitov 106672b603eeSAlexei Starovoitov if (insn->dst_reg == BPF_REG_4) 106772b603eeSAlexei Starovoitov /* mov dst_reg, r11 */ 106872b603eeSAlexei Starovoitov EMIT_mov(insn->dst_reg, AUX_REG); 106972b603eeSAlexei Starovoitov break; 107072b603eeSAlexei Starovoitov 107162258278SAlexei Starovoitov case BPF_ALU | BPF_END | BPF_FROM_BE: 1072e430f34eSAlexei Starovoitov switch (imm32) { 107362258278SAlexei Starovoitov case 16: 1074a2c7a983SIngo Molnar /* Emit 'ror %ax, 8' to swap lower 2 bytes */ 107562258278SAlexei Starovoitov EMIT1(0x66); 1076e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 107762258278SAlexei Starovoitov EMIT1(0x41); 1078e430f34eSAlexei Starovoitov EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); 1079343f845bSAlexei Starovoitov 1080a2c7a983SIngo Molnar /* Emit 'movzwl eax, ax' */ 1081343f845bSAlexei Starovoitov if (is_ereg(dst_reg)) 1082343f845bSAlexei Starovoitov EMIT3(0x45, 0x0F, 0xB7); 1083343f845bSAlexei Starovoitov else 1084343f845bSAlexei Starovoitov EMIT2(0x0F, 0xB7); 1085343f845bSAlexei Starovoitov EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); 108662258278SAlexei Starovoitov break; 108762258278SAlexei Starovoitov case 32: 1088a2c7a983SIngo Molnar /* Emit 'bswap eax' to swap lower 4 bytes */ 1089e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 109062258278SAlexei Starovoitov EMIT2(0x41, 0x0F); 109162258278SAlexei Starovoitov else 109262258278SAlexei Starovoitov EMIT1(0x0F); 1093e430f34eSAlexei Starovoitov EMIT1(add_1reg(0xC8, dst_reg)); 109462258278SAlexei Starovoitov break; 109562258278SAlexei Starovoitov case 64: 1096a2c7a983SIngo Molnar /* Emit 'bswap rax' to swap 8 bytes */ 1097e430f34eSAlexei Starovoitov EMIT3(add_1mod(0x48, dst_reg), 0x0F, 1098e430f34eSAlexei Starovoitov add_1reg(0xC8, dst_reg)); 109962258278SAlexei Starovoitov break; 110062258278SAlexei Starovoitov } 110162258278SAlexei Starovoitov break; 110262258278SAlexei Starovoitov 110362258278SAlexei Starovoitov case BPF_ALU | BPF_END | BPF_FROM_LE: 1104343f845bSAlexei Starovoitov switch (imm32) { 1105343f845bSAlexei Starovoitov case 16: 1106a2c7a983SIngo Molnar /* 1107a2c7a983SIngo Molnar * Emit 'movzwl eax, ax' to zero extend 16-bit 1108343f845bSAlexei Starovoitov * into 64 bit 1109343f845bSAlexei Starovoitov */ 1110343f845bSAlexei Starovoitov if (is_ereg(dst_reg)) 1111343f845bSAlexei Starovoitov EMIT3(0x45, 0x0F, 0xB7); 1112343f845bSAlexei Starovoitov else 1113343f845bSAlexei Starovoitov EMIT2(0x0F, 0xB7); 1114343f845bSAlexei Starovoitov EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); 1115343f845bSAlexei Starovoitov break; 1116343f845bSAlexei Starovoitov case 32: 1117a2c7a983SIngo Molnar /* Emit 'mov eax, eax' to clear upper 32-bits */ 1118343f845bSAlexei Starovoitov if (is_ereg(dst_reg)) 1119343f845bSAlexei Starovoitov EMIT1(0x45); 1120343f845bSAlexei Starovoitov EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); 1121343f845bSAlexei Starovoitov break; 1122343f845bSAlexei Starovoitov case 64: 1123343f845bSAlexei Starovoitov /* nop */ 1124343f845bSAlexei Starovoitov break; 1125343f845bSAlexei Starovoitov } 112662258278SAlexei Starovoitov break; 112762258278SAlexei Starovoitov 1128e430f34eSAlexei Starovoitov /* ST: *(u8*)(dst_reg + off) = imm */ 112962258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_B: 1130e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 113162258278SAlexei Starovoitov EMIT2(0x41, 0xC6); 113262258278SAlexei Starovoitov else 113362258278SAlexei Starovoitov EMIT1(0xC6); 113462258278SAlexei Starovoitov goto st; 113562258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_H: 1136e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 113762258278SAlexei Starovoitov EMIT3(0x66, 0x41, 0xC7); 113862258278SAlexei Starovoitov else 113962258278SAlexei Starovoitov EMIT2(0x66, 0xC7); 114062258278SAlexei Starovoitov goto st; 114162258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_W: 1142e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 114362258278SAlexei Starovoitov EMIT2(0x41, 0xC7); 114462258278SAlexei Starovoitov else 114562258278SAlexei Starovoitov EMIT1(0xC7); 114662258278SAlexei Starovoitov goto st; 114762258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_DW: 1148e430f34eSAlexei Starovoitov EMIT2(add_1mod(0x48, dst_reg), 0xC7); 114962258278SAlexei Starovoitov 115062258278SAlexei Starovoitov st: if (is_imm8(insn->off)) 1151e430f34eSAlexei Starovoitov EMIT2(add_1reg(0x40, dst_reg), insn->off); 115262258278SAlexei Starovoitov else 1153e430f34eSAlexei Starovoitov EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); 115462258278SAlexei Starovoitov 1155e430f34eSAlexei Starovoitov EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); 115662258278SAlexei Starovoitov break; 115762258278SAlexei Starovoitov 1158e430f34eSAlexei Starovoitov /* STX: *(u8*)(dst_reg + off) = src_reg */ 115962258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_B: 116062258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_H: 116162258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_W: 116262258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_DW: 11633b2744e6SAlexei Starovoitov emit_stx(&prog, BPF_SIZE(insn->code), dst_reg, src_reg, insn->off); 116462258278SAlexei Starovoitov break; 116562258278SAlexei Starovoitov 1166e430f34eSAlexei Starovoitov /* LDX: dst_reg = *(u8*)(src_reg + off) */ 116762258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_B: 11683dec541bSAlexei Starovoitov case BPF_LDX | BPF_PROBE_MEM | BPF_B: 116962258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_H: 11703dec541bSAlexei Starovoitov case BPF_LDX | BPF_PROBE_MEM | BPF_H: 117162258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_W: 11723dec541bSAlexei Starovoitov case BPF_LDX | BPF_PROBE_MEM | BPF_W: 117362258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_DW: 11743dec541bSAlexei Starovoitov case BPF_LDX | BPF_PROBE_MEM | BPF_DW: 11753b2744e6SAlexei Starovoitov emit_ldx(&prog, BPF_SIZE(insn->code), dst_reg, src_reg, insn->off); 11763dec541bSAlexei Starovoitov if (BPF_MODE(insn->code) == BPF_PROBE_MEM) { 11773dec541bSAlexei Starovoitov struct exception_table_entry *ex; 11783dec541bSAlexei Starovoitov u8 *_insn = image + proglen; 11793dec541bSAlexei Starovoitov s64 delta; 11803dec541bSAlexei Starovoitov 11813dec541bSAlexei Starovoitov if (!bpf_prog->aux->extable) 11823dec541bSAlexei Starovoitov break; 11833dec541bSAlexei Starovoitov 11843dec541bSAlexei Starovoitov if (excnt >= bpf_prog->aux->num_exentries) { 11853dec541bSAlexei Starovoitov pr_err("ex gen bug\n"); 11863dec541bSAlexei Starovoitov return -EFAULT; 11873dec541bSAlexei Starovoitov } 11883dec541bSAlexei Starovoitov ex = &bpf_prog->aux->extable[excnt++]; 11893dec541bSAlexei Starovoitov 11903dec541bSAlexei Starovoitov delta = _insn - (u8 *)&ex->insn; 11913dec541bSAlexei Starovoitov if (!is_simm32(delta)) { 11923dec541bSAlexei Starovoitov pr_err("extable->insn doesn't fit into 32-bit\n"); 11933dec541bSAlexei Starovoitov return -EFAULT; 11943dec541bSAlexei Starovoitov } 11953dec541bSAlexei Starovoitov ex->insn = delta; 11963dec541bSAlexei Starovoitov 11973dec541bSAlexei Starovoitov delta = (u8 *)ex_handler_bpf - (u8 *)&ex->handler; 11983dec541bSAlexei Starovoitov if (!is_simm32(delta)) { 11993dec541bSAlexei Starovoitov pr_err("extable->handler doesn't fit into 32-bit\n"); 12003dec541bSAlexei Starovoitov return -EFAULT; 12013dec541bSAlexei Starovoitov } 12023dec541bSAlexei Starovoitov ex->handler = delta; 12033dec541bSAlexei Starovoitov 12043dec541bSAlexei Starovoitov if (dst_reg > BPF_REG_9) { 12053dec541bSAlexei Starovoitov pr_err("verifier error\n"); 12063dec541bSAlexei Starovoitov return -EFAULT; 12073dec541bSAlexei Starovoitov } 12083dec541bSAlexei Starovoitov /* 12093dec541bSAlexei Starovoitov * Compute size of x86 insn and its target dest x86 register. 12103dec541bSAlexei Starovoitov * ex_handler_bpf() will use lower 8 bits to adjust 12113dec541bSAlexei Starovoitov * pt_regs->ip to jump over this x86 instruction 12123dec541bSAlexei Starovoitov * and upper bits to figure out which pt_regs to zero out. 12133dec541bSAlexei Starovoitov * End result: x86 insn "mov rbx, qword ptr [rax+0x14]" 12143dec541bSAlexei Starovoitov * of 4 bytes will be ignored and rbx will be zero inited. 12153dec541bSAlexei Starovoitov */ 12163dec541bSAlexei Starovoitov ex->fixup = (prog - temp) | (reg2pt_regs[dst_reg] << 8); 12173dec541bSAlexei Starovoitov } 121862258278SAlexei Starovoitov break; 121962258278SAlexei Starovoitov 1220e430f34eSAlexei Starovoitov /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ 122162258278SAlexei Starovoitov case BPF_STX | BPF_XADD | BPF_W: 1222a2c7a983SIngo Molnar /* Emit 'lock add dword ptr [rax + off], eax' */ 1223e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 1224e430f34eSAlexei Starovoitov EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); 122562258278SAlexei Starovoitov else 122662258278SAlexei Starovoitov EMIT2(0xF0, 0x01); 122762258278SAlexei Starovoitov goto xadd; 122862258278SAlexei Starovoitov case BPF_STX | BPF_XADD | BPF_DW: 1229e430f34eSAlexei Starovoitov EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); 123062258278SAlexei Starovoitov xadd: if (is_imm8(insn->off)) 1231e430f34eSAlexei Starovoitov EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); 123262258278SAlexei Starovoitov else 1233e430f34eSAlexei Starovoitov EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), 123462258278SAlexei Starovoitov insn->off); 123562258278SAlexei Starovoitov break; 123662258278SAlexei Starovoitov 123762258278SAlexei Starovoitov /* call */ 123862258278SAlexei Starovoitov case BPF_JMP | BPF_CALL: 1239e430f34eSAlexei Starovoitov func = (u8 *) __bpf_call_base + imm32; 1240ebf7d1f5SMaciej Fijalkowski if (tail_call_reachable) { 1241ebf7d1f5SMaciej Fijalkowski EMIT3_off32(0x48, 0x8B, 0x85, 1242ebf7d1f5SMaciej Fijalkowski -(bpf_prog->aux->stack_depth + 8)); 1243ebf7d1f5SMaciej Fijalkowski if (!imm32 || emit_call(&prog, func, image + addrs[i - 1] + 7)) 1244ebf7d1f5SMaciej Fijalkowski return -EINVAL; 1245ebf7d1f5SMaciej Fijalkowski } else { 12463b2744e6SAlexei Starovoitov if (!imm32 || emit_call(&prog, func, image + addrs[i - 1])) 1247f3c2af7bSAlexei Starovoitov return -EINVAL; 1248ebf7d1f5SMaciej Fijalkowski } 124962258278SAlexei Starovoitov break; 125062258278SAlexei Starovoitov 125171189fa9SAlexei Starovoitov case BPF_JMP | BPF_TAIL_CALL: 1252428d5df1SDaniel Borkmann if (imm32) 1253428d5df1SDaniel Borkmann emit_bpf_tail_call_direct(&bpf_prog->aux->poke_tab[imm32 - 1], 1254ebf7d1f5SMaciej Fijalkowski &prog, addrs[i], image, 1255ebf7d1f5SMaciej Fijalkowski callee_regs_used, 1256ebf7d1f5SMaciej Fijalkowski bpf_prog->aux->stack_depth); 1257428d5df1SDaniel Borkmann else 1258ebf7d1f5SMaciej Fijalkowski emit_bpf_tail_call_indirect(&prog, 1259ebf7d1f5SMaciej Fijalkowski callee_regs_used, 1260ebf7d1f5SMaciej Fijalkowski bpf_prog->aux->stack_depth); 1261b52f00e6SAlexei Starovoitov break; 1262b52f00e6SAlexei Starovoitov 126362258278SAlexei Starovoitov /* cond jump */ 126462258278SAlexei Starovoitov case BPF_JMP | BPF_JEQ | BPF_X: 126562258278SAlexei Starovoitov case BPF_JMP | BPF_JNE | BPF_X: 126662258278SAlexei Starovoitov case BPF_JMP | BPF_JGT | BPF_X: 126752afc51eSDaniel Borkmann case BPF_JMP | BPF_JLT | BPF_X: 126862258278SAlexei Starovoitov case BPF_JMP | BPF_JGE | BPF_X: 126952afc51eSDaniel Borkmann case BPF_JMP | BPF_JLE | BPF_X: 127062258278SAlexei Starovoitov case BPF_JMP | BPF_JSGT | BPF_X: 127152afc51eSDaniel Borkmann case BPF_JMP | BPF_JSLT | BPF_X: 127262258278SAlexei Starovoitov case BPF_JMP | BPF_JSGE | BPF_X: 127352afc51eSDaniel Borkmann case BPF_JMP | BPF_JSLE | BPF_X: 12743f5d6525SJiong Wang case BPF_JMP32 | BPF_JEQ | BPF_X: 12753f5d6525SJiong Wang case BPF_JMP32 | BPF_JNE | BPF_X: 12763f5d6525SJiong Wang case BPF_JMP32 | BPF_JGT | BPF_X: 12773f5d6525SJiong Wang case BPF_JMP32 | BPF_JLT | BPF_X: 12783f5d6525SJiong Wang case BPF_JMP32 | BPF_JGE | BPF_X: 12793f5d6525SJiong Wang case BPF_JMP32 | BPF_JLE | BPF_X: 12803f5d6525SJiong Wang case BPF_JMP32 | BPF_JSGT | BPF_X: 12813f5d6525SJiong Wang case BPF_JMP32 | BPF_JSLT | BPF_X: 12823f5d6525SJiong Wang case BPF_JMP32 | BPF_JSGE | BPF_X: 12833f5d6525SJiong Wang case BPF_JMP32 | BPF_JSLE | BPF_X: 1284e430f34eSAlexei Starovoitov /* cmp dst_reg, src_reg */ 12853f5d6525SJiong Wang if (BPF_CLASS(insn->code) == BPF_JMP) 12863f5d6525SJiong Wang EMIT1(add_2mod(0x48, dst_reg, src_reg)); 12873f5d6525SJiong Wang else if (is_ereg(dst_reg) || is_ereg(src_reg)) 12883f5d6525SJiong Wang EMIT1(add_2mod(0x40, dst_reg, src_reg)); 12893f5d6525SJiong Wang EMIT2(0x39, add_2reg(0xC0, dst_reg, src_reg)); 129062258278SAlexei Starovoitov goto emit_cond_jmp; 129162258278SAlexei Starovoitov 129262258278SAlexei Starovoitov case BPF_JMP | BPF_JSET | BPF_X: 12933f5d6525SJiong Wang case BPF_JMP32 | BPF_JSET | BPF_X: 1294e430f34eSAlexei Starovoitov /* test dst_reg, src_reg */ 12953f5d6525SJiong Wang if (BPF_CLASS(insn->code) == BPF_JMP) 12963f5d6525SJiong Wang EMIT1(add_2mod(0x48, dst_reg, src_reg)); 12973f5d6525SJiong Wang else if (is_ereg(dst_reg) || is_ereg(src_reg)) 12983f5d6525SJiong Wang EMIT1(add_2mod(0x40, dst_reg, src_reg)); 12993f5d6525SJiong Wang EMIT2(0x85, add_2reg(0xC0, dst_reg, src_reg)); 130062258278SAlexei Starovoitov goto emit_cond_jmp; 130162258278SAlexei Starovoitov 130262258278SAlexei Starovoitov case BPF_JMP | BPF_JSET | BPF_K: 13033f5d6525SJiong Wang case BPF_JMP32 | BPF_JSET | BPF_K: 1304e430f34eSAlexei Starovoitov /* test dst_reg, imm32 */ 13053f5d6525SJiong Wang if (BPF_CLASS(insn->code) == BPF_JMP) 1306e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 13073f5d6525SJiong Wang else if (is_ereg(dst_reg)) 13083f5d6525SJiong Wang EMIT1(add_1mod(0x40, dst_reg)); 1309e430f34eSAlexei Starovoitov EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); 131062258278SAlexei Starovoitov goto emit_cond_jmp; 131162258278SAlexei Starovoitov 131262258278SAlexei Starovoitov case BPF_JMP | BPF_JEQ | BPF_K: 131362258278SAlexei Starovoitov case BPF_JMP | BPF_JNE | BPF_K: 131462258278SAlexei Starovoitov case BPF_JMP | BPF_JGT | BPF_K: 131552afc51eSDaniel Borkmann case BPF_JMP | BPF_JLT | BPF_K: 131662258278SAlexei Starovoitov case BPF_JMP | BPF_JGE | BPF_K: 131752afc51eSDaniel Borkmann case BPF_JMP | BPF_JLE | BPF_K: 131862258278SAlexei Starovoitov case BPF_JMP | BPF_JSGT | BPF_K: 131952afc51eSDaniel Borkmann case BPF_JMP | BPF_JSLT | BPF_K: 132062258278SAlexei Starovoitov case BPF_JMP | BPF_JSGE | BPF_K: 132152afc51eSDaniel Borkmann case BPF_JMP | BPF_JSLE | BPF_K: 13223f5d6525SJiong Wang case BPF_JMP32 | BPF_JEQ | BPF_K: 13233f5d6525SJiong Wang case BPF_JMP32 | BPF_JNE | BPF_K: 13243f5d6525SJiong Wang case BPF_JMP32 | BPF_JGT | BPF_K: 13253f5d6525SJiong Wang case BPF_JMP32 | BPF_JLT | BPF_K: 13263f5d6525SJiong Wang case BPF_JMP32 | BPF_JGE | BPF_K: 13273f5d6525SJiong Wang case BPF_JMP32 | BPF_JLE | BPF_K: 13283f5d6525SJiong Wang case BPF_JMP32 | BPF_JSGT | BPF_K: 13293f5d6525SJiong Wang case BPF_JMP32 | BPF_JSLT | BPF_K: 13303f5d6525SJiong Wang case BPF_JMP32 | BPF_JSGE | BPF_K: 13313f5d6525SJiong Wang case BPF_JMP32 | BPF_JSLE | BPF_K: 133238f51c07SDaniel Borkmann /* test dst_reg, dst_reg to save one extra byte */ 133338f51c07SDaniel Borkmann if (imm32 == 0) { 133438f51c07SDaniel Borkmann if (BPF_CLASS(insn->code) == BPF_JMP) 133538f51c07SDaniel Borkmann EMIT1(add_2mod(0x48, dst_reg, dst_reg)); 133638f51c07SDaniel Borkmann else if (is_ereg(dst_reg)) 133738f51c07SDaniel Borkmann EMIT1(add_2mod(0x40, dst_reg, dst_reg)); 133838f51c07SDaniel Borkmann EMIT2(0x85, add_2reg(0xC0, dst_reg, dst_reg)); 133938f51c07SDaniel Borkmann goto emit_cond_jmp; 134038f51c07SDaniel Borkmann } 134138f51c07SDaniel Borkmann 1342e430f34eSAlexei Starovoitov /* cmp dst_reg, imm8/32 */ 13433f5d6525SJiong Wang if (BPF_CLASS(insn->code) == BPF_JMP) 1344e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 13453f5d6525SJiong Wang else if (is_ereg(dst_reg)) 13463f5d6525SJiong Wang EMIT1(add_1mod(0x40, dst_reg)); 134762258278SAlexei Starovoitov 1348e430f34eSAlexei Starovoitov if (is_imm8(imm32)) 1349e430f34eSAlexei Starovoitov EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); 135062258278SAlexei Starovoitov else 1351e430f34eSAlexei Starovoitov EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); 135262258278SAlexei Starovoitov 1353a2c7a983SIngo Molnar emit_cond_jmp: /* Convert BPF opcode to x86 */ 135462258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 135562258278SAlexei Starovoitov case BPF_JEQ: 135662258278SAlexei Starovoitov jmp_cond = X86_JE; 135762258278SAlexei Starovoitov break; 135862258278SAlexei Starovoitov case BPF_JSET: 135962258278SAlexei Starovoitov case BPF_JNE: 136062258278SAlexei Starovoitov jmp_cond = X86_JNE; 136162258278SAlexei Starovoitov break; 136262258278SAlexei Starovoitov case BPF_JGT: 136362258278SAlexei Starovoitov /* GT is unsigned '>', JA in x86 */ 136462258278SAlexei Starovoitov jmp_cond = X86_JA; 136562258278SAlexei Starovoitov break; 136652afc51eSDaniel Borkmann case BPF_JLT: 136752afc51eSDaniel Borkmann /* LT is unsigned '<', JB in x86 */ 136852afc51eSDaniel Borkmann jmp_cond = X86_JB; 136952afc51eSDaniel Borkmann break; 137062258278SAlexei Starovoitov case BPF_JGE: 137162258278SAlexei Starovoitov /* GE is unsigned '>=', JAE in x86 */ 137262258278SAlexei Starovoitov jmp_cond = X86_JAE; 137362258278SAlexei Starovoitov break; 137452afc51eSDaniel Borkmann case BPF_JLE: 137552afc51eSDaniel Borkmann /* LE is unsigned '<=', JBE in x86 */ 137652afc51eSDaniel Borkmann jmp_cond = X86_JBE; 137752afc51eSDaniel Borkmann break; 137862258278SAlexei Starovoitov case BPF_JSGT: 1379a2c7a983SIngo Molnar /* Signed '>', GT in x86 */ 138062258278SAlexei Starovoitov jmp_cond = X86_JG; 138162258278SAlexei Starovoitov break; 138252afc51eSDaniel Borkmann case BPF_JSLT: 1383a2c7a983SIngo Molnar /* Signed '<', LT in x86 */ 138452afc51eSDaniel Borkmann jmp_cond = X86_JL; 138552afc51eSDaniel Borkmann break; 138662258278SAlexei Starovoitov case BPF_JSGE: 1387a2c7a983SIngo Molnar /* Signed '>=', GE in x86 */ 138862258278SAlexei Starovoitov jmp_cond = X86_JGE; 138962258278SAlexei Starovoitov break; 139052afc51eSDaniel Borkmann case BPF_JSLE: 1391a2c7a983SIngo Molnar /* Signed '<=', LE in x86 */ 139252afc51eSDaniel Borkmann jmp_cond = X86_JLE; 139352afc51eSDaniel Borkmann break; 1394a2c7a983SIngo Molnar default: /* to silence GCC warning */ 139562258278SAlexei Starovoitov return -EFAULT; 139662258278SAlexei Starovoitov } 139762258278SAlexei Starovoitov jmp_offset = addrs[i + insn->off] - addrs[i]; 139862258278SAlexei Starovoitov if (is_imm8(jmp_offset)) { 139962258278SAlexei Starovoitov EMIT2(jmp_cond, jmp_offset); 140062258278SAlexei Starovoitov } else if (is_simm32(jmp_offset)) { 140162258278SAlexei Starovoitov EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); 14023b58908aSEric Dumazet } else { 140362258278SAlexei Starovoitov pr_err("cond_jmp gen bug %llx\n", jmp_offset); 140462258278SAlexei Starovoitov return -EFAULT; 14053b58908aSEric Dumazet } 140662258278SAlexei Starovoitov 14073b58908aSEric Dumazet break; 140862258278SAlexei Starovoitov 140962258278SAlexei Starovoitov case BPF_JMP | BPF_JA: 14101612a981SGianluca Borello if (insn->off == -1) 14111612a981SGianluca Borello /* -1 jmp instructions will always jump 14121612a981SGianluca Borello * backwards two bytes. Explicitly handling 14131612a981SGianluca Borello * this case avoids wasting too many passes 14141612a981SGianluca Borello * when there are long sequences of replaced 14151612a981SGianluca Borello * dead code. 14161612a981SGianluca Borello */ 14171612a981SGianluca Borello jmp_offset = -2; 14181612a981SGianluca Borello else 141962258278SAlexei Starovoitov jmp_offset = addrs[i + insn->off] - addrs[i]; 14201612a981SGianluca Borello 142162258278SAlexei Starovoitov if (!jmp_offset) 1422a2c7a983SIngo Molnar /* Optimize out nop jumps */ 142362258278SAlexei Starovoitov break; 142462258278SAlexei Starovoitov emit_jmp: 142562258278SAlexei Starovoitov if (is_imm8(jmp_offset)) { 142662258278SAlexei Starovoitov EMIT2(0xEB, jmp_offset); 142762258278SAlexei Starovoitov } else if (is_simm32(jmp_offset)) { 142862258278SAlexei Starovoitov EMIT1_off32(0xE9, jmp_offset); 142962258278SAlexei Starovoitov } else { 143062258278SAlexei Starovoitov pr_err("jmp gen bug %llx\n", jmp_offset); 143162258278SAlexei Starovoitov return -EFAULT; 14323b58908aSEric Dumazet } 143362258278SAlexei Starovoitov break; 143462258278SAlexei Starovoitov 143562258278SAlexei Starovoitov case BPF_JMP | BPF_EXIT: 1436769e0de6SAlexei Starovoitov if (seen_exit) { 143762258278SAlexei Starovoitov jmp_offset = ctx->cleanup_addr - addrs[i]; 143862258278SAlexei Starovoitov goto emit_jmp; 143962258278SAlexei Starovoitov } 1440769e0de6SAlexei Starovoitov seen_exit = true; 1441a2c7a983SIngo Molnar /* Update cleanup_addr */ 144262258278SAlexei Starovoitov ctx->cleanup_addr = proglen; 1443ebf7d1f5SMaciej Fijalkowski pop_callee_regs(&prog, callee_regs_used); 1444ebf7d1f5SMaciej Fijalkowski if (tail_call_reachable) 1445ebf7d1f5SMaciej Fijalkowski EMIT1(0x59); /* pop rcx, get rid of tail_call_cnt */ 144662258278SAlexei Starovoitov EMIT1(0xC9); /* leave */ 144762258278SAlexei Starovoitov EMIT1(0xC3); /* ret */ 14480a14842fSEric Dumazet break; 14490a14842fSEric Dumazet 14500a14842fSEric Dumazet default: 1451a2c7a983SIngo Molnar /* 1452a2c7a983SIngo Molnar * By design x86-64 JIT should support all BPF instructions. 145362258278SAlexei Starovoitov * This error will be seen if new instruction was added 1454a2c7a983SIngo Molnar * to the interpreter, but not to the JIT, or if there is 1455a2c7a983SIngo Molnar * junk in bpf_prog. 145662258278SAlexei Starovoitov */ 145762258278SAlexei Starovoitov pr_err("bpf_jit: unknown opcode %02x\n", insn->code); 1458f3c2af7bSAlexei Starovoitov return -EINVAL; 14590a14842fSEric Dumazet } 146062258278SAlexei Starovoitov 14610a14842fSEric Dumazet ilen = prog - temp; 1462e0ee9c12SAlexei Starovoitov if (ilen > BPF_MAX_INSN_SIZE) { 14639383191dSDaniel Borkmann pr_err("bpf_jit: fatal insn size error\n"); 1464e0ee9c12SAlexei Starovoitov return -EFAULT; 1465e0ee9c12SAlexei Starovoitov } 1466e0ee9c12SAlexei Starovoitov 14670a14842fSEric Dumazet if (image) { 14680a14842fSEric Dumazet if (unlikely(proglen + ilen > oldproglen)) { 14699383191dSDaniel Borkmann pr_err("bpf_jit: fatal error\n"); 1470f3c2af7bSAlexei Starovoitov return -EFAULT; 14710a14842fSEric Dumazet } 14720a14842fSEric Dumazet memcpy(image + proglen, temp, ilen); 14730a14842fSEric Dumazet } 14740a14842fSEric Dumazet proglen += ilen; 14750a14842fSEric Dumazet addrs[i] = proglen; 14760a14842fSEric Dumazet prog = temp; 14770a14842fSEric Dumazet } 14783dec541bSAlexei Starovoitov 14793dec541bSAlexei Starovoitov if (image && excnt != bpf_prog->aux->num_exentries) { 14803dec541bSAlexei Starovoitov pr_err("extable is not populated\n"); 14813dec541bSAlexei Starovoitov return -EFAULT; 14823dec541bSAlexei Starovoitov } 1483f3c2af7bSAlexei Starovoitov return proglen; 1484f3c2af7bSAlexei Starovoitov } 1485f3c2af7bSAlexei Starovoitov 148685d33df3SMartin KaFai Lau static void save_regs(const struct btf_func_model *m, u8 **prog, int nr_args, 1487fec56f58SAlexei Starovoitov int stack_size) 1488fec56f58SAlexei Starovoitov { 1489fec56f58SAlexei Starovoitov int i; 1490fec56f58SAlexei Starovoitov /* Store function arguments to stack. 1491fec56f58SAlexei Starovoitov * For a function that accepts two pointers the sequence will be: 1492fec56f58SAlexei Starovoitov * mov QWORD PTR [rbp-0x10],rdi 1493fec56f58SAlexei Starovoitov * mov QWORD PTR [rbp-0x8],rsi 1494fec56f58SAlexei Starovoitov */ 1495fec56f58SAlexei Starovoitov for (i = 0; i < min(nr_args, 6); i++) 1496fec56f58SAlexei Starovoitov emit_stx(prog, bytes_to_bpf_size(m->arg_size[i]), 1497fec56f58SAlexei Starovoitov BPF_REG_FP, 1498fec56f58SAlexei Starovoitov i == 5 ? X86_REG_R9 : BPF_REG_1 + i, 1499fec56f58SAlexei Starovoitov -(stack_size - i * 8)); 1500fec56f58SAlexei Starovoitov } 1501fec56f58SAlexei Starovoitov 150285d33df3SMartin KaFai Lau static void restore_regs(const struct btf_func_model *m, u8 **prog, int nr_args, 1503fec56f58SAlexei Starovoitov int stack_size) 1504fec56f58SAlexei Starovoitov { 1505fec56f58SAlexei Starovoitov int i; 1506fec56f58SAlexei Starovoitov 1507fec56f58SAlexei Starovoitov /* Restore function arguments from stack. 1508fec56f58SAlexei Starovoitov * For a function that accepts two pointers the sequence will be: 1509fec56f58SAlexei Starovoitov * EMIT4(0x48, 0x8B, 0x7D, 0xF0); mov rdi,QWORD PTR [rbp-0x10] 1510fec56f58SAlexei Starovoitov * EMIT4(0x48, 0x8B, 0x75, 0xF8); mov rsi,QWORD PTR [rbp-0x8] 1511fec56f58SAlexei Starovoitov */ 1512fec56f58SAlexei Starovoitov for (i = 0; i < min(nr_args, 6); i++) 1513fec56f58SAlexei Starovoitov emit_ldx(prog, bytes_to_bpf_size(m->arg_size[i]), 1514fec56f58SAlexei Starovoitov i == 5 ? X86_REG_R9 : BPF_REG_1 + i, 1515fec56f58SAlexei Starovoitov BPF_REG_FP, 1516fec56f58SAlexei Starovoitov -(stack_size - i * 8)); 1517fec56f58SAlexei Starovoitov } 1518fec56f58SAlexei Starovoitov 15197e639208SKP Singh static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, 1520ae240823SKP Singh struct bpf_prog *p, int stack_size, bool mod_ret) 1521fec56f58SAlexei Starovoitov { 1522fec56f58SAlexei Starovoitov u8 *prog = *pprog; 15237e639208SKP Singh int cnt = 0; 1524fec56f58SAlexei Starovoitov 15251e6c62a8SAlexei Starovoitov if (p->aux->sleepable) { 15261e6c62a8SAlexei Starovoitov if (emit_call(&prog, __bpf_prog_enter_sleepable, prog)) 15271e6c62a8SAlexei Starovoitov return -EINVAL; 15281e6c62a8SAlexei Starovoitov } else { 1529fec56f58SAlexei Starovoitov if (emit_call(&prog, __bpf_prog_enter, prog)) 1530fec56f58SAlexei Starovoitov return -EINVAL; 1531fec56f58SAlexei Starovoitov /* remember prog start time returned by __bpf_prog_enter */ 1532fec56f58SAlexei Starovoitov emit_mov_reg(&prog, true, BPF_REG_6, BPF_REG_0); 15331e6c62a8SAlexei Starovoitov } 1534fec56f58SAlexei Starovoitov 1535fec56f58SAlexei Starovoitov /* arg1: lea rdi, [rbp - stack_size] */ 1536fec56f58SAlexei Starovoitov EMIT4(0x48, 0x8D, 0x7D, -stack_size); 1537fec56f58SAlexei Starovoitov /* arg2: progs[i]->insnsi for interpreter */ 15387e639208SKP Singh if (!p->jited) 1539fec56f58SAlexei Starovoitov emit_mov_imm64(&prog, BPF_REG_2, 15407e639208SKP Singh (long) p->insnsi >> 32, 15417e639208SKP Singh (u32) (long) p->insnsi); 1542fec56f58SAlexei Starovoitov /* call JITed bpf program or interpreter */ 15437e639208SKP Singh if (emit_call(&prog, p->bpf_func, prog)) 1544fec56f58SAlexei Starovoitov return -EINVAL; 1545fec56f58SAlexei Starovoitov 1546ae240823SKP Singh /* BPF_TRAMP_MODIFY_RETURN trampolines can modify the return 1547ae240823SKP Singh * of the previous call which is then passed on the stack to 1548ae240823SKP Singh * the next BPF program. 1549ae240823SKP Singh */ 1550ae240823SKP Singh if (mod_ret) 1551ae240823SKP Singh emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8); 1552ae240823SKP Singh 15531e6c62a8SAlexei Starovoitov if (p->aux->sleepable) { 15541e6c62a8SAlexei Starovoitov if (emit_call(&prog, __bpf_prog_exit_sleepable, prog)) 15551e6c62a8SAlexei Starovoitov return -EINVAL; 15561e6c62a8SAlexei Starovoitov } else { 1557fec56f58SAlexei Starovoitov /* arg1: mov rdi, progs[i] */ 15587e639208SKP Singh emit_mov_imm64(&prog, BPF_REG_1, (long) p >> 32, 15597e639208SKP Singh (u32) (long) p); 1560fec56f58SAlexei Starovoitov /* arg2: mov rsi, rbx <- start time in nsec */ 1561fec56f58SAlexei Starovoitov emit_mov_reg(&prog, true, BPF_REG_2, BPF_REG_6); 1562fec56f58SAlexei Starovoitov if (emit_call(&prog, __bpf_prog_exit, prog)) 1563fec56f58SAlexei Starovoitov return -EINVAL; 15641e6c62a8SAlexei Starovoitov } 15657e639208SKP Singh 15667e639208SKP Singh *pprog = prog; 15677e639208SKP Singh return 0; 15687e639208SKP Singh } 15697e639208SKP Singh 15707e639208SKP Singh static void emit_nops(u8 **pprog, unsigned int len) 15717e639208SKP Singh { 15727e639208SKP Singh unsigned int i, noplen; 15737e639208SKP Singh u8 *prog = *pprog; 15747e639208SKP Singh int cnt = 0; 15757e639208SKP Singh 15767e639208SKP Singh while (len > 0) { 15777e639208SKP Singh noplen = len; 15787e639208SKP Singh 15797e639208SKP Singh if (noplen > ASM_NOP_MAX) 15807e639208SKP Singh noplen = ASM_NOP_MAX; 15817e639208SKP Singh 15827e639208SKP Singh for (i = 0; i < noplen; i++) 15837e639208SKP Singh EMIT1(ideal_nops[noplen][i]); 15847e639208SKP Singh len -= noplen; 15857e639208SKP Singh } 15867e639208SKP Singh 15877e639208SKP Singh *pprog = prog; 15887e639208SKP Singh } 15897e639208SKP Singh 15907e639208SKP Singh static void emit_align(u8 **pprog, u32 align) 15917e639208SKP Singh { 15927e639208SKP Singh u8 *target, *prog = *pprog; 15937e639208SKP Singh 15947e639208SKP Singh target = PTR_ALIGN(prog, align); 15957e639208SKP Singh if (target != prog) 15967e639208SKP Singh emit_nops(&prog, target - prog); 15977e639208SKP Singh 15987e639208SKP Singh *pprog = prog; 15997e639208SKP Singh } 16007e639208SKP Singh 16017e639208SKP Singh static int emit_cond_near_jump(u8 **pprog, void *func, void *ip, u8 jmp_cond) 16027e639208SKP Singh { 16037e639208SKP Singh u8 *prog = *pprog; 16047e639208SKP Singh int cnt = 0; 16057e639208SKP Singh s64 offset; 16067e639208SKP Singh 16077e639208SKP Singh offset = func - (ip + 2 + 4); 16087e639208SKP Singh if (!is_simm32(offset)) { 16097e639208SKP Singh pr_err("Target %p is out of range\n", func); 16107e639208SKP Singh return -EINVAL; 16117e639208SKP Singh } 16127e639208SKP Singh EMIT2_off32(0x0F, jmp_cond + 0x10, offset); 16137e639208SKP Singh *pprog = prog; 16147e639208SKP Singh return 0; 16157e639208SKP Singh } 16167e639208SKP Singh 16177e639208SKP Singh static int invoke_bpf(const struct btf_func_model *m, u8 **pprog, 16187e639208SKP Singh struct bpf_tramp_progs *tp, int stack_size) 16197e639208SKP Singh { 16207e639208SKP Singh int i; 16217e639208SKP Singh u8 *prog = *pprog; 16227e639208SKP Singh 16237e639208SKP Singh for (i = 0; i < tp->nr_progs; i++) { 1624ae240823SKP Singh if (invoke_bpf_prog(m, &prog, tp->progs[i], stack_size, false)) 16257e639208SKP Singh return -EINVAL; 1626fec56f58SAlexei Starovoitov } 1627fec56f58SAlexei Starovoitov *pprog = prog; 1628fec56f58SAlexei Starovoitov return 0; 1629fec56f58SAlexei Starovoitov } 1630fec56f58SAlexei Starovoitov 1631ae240823SKP Singh static int invoke_bpf_mod_ret(const struct btf_func_model *m, u8 **pprog, 1632ae240823SKP Singh struct bpf_tramp_progs *tp, int stack_size, 1633ae240823SKP Singh u8 **branches) 1634ae240823SKP Singh { 1635ae240823SKP Singh u8 *prog = *pprog; 163613fac1d8SAlexei Starovoitov int i, cnt = 0; 1637ae240823SKP Singh 1638ae240823SKP Singh /* The first fmod_ret program will receive a garbage return value. 1639ae240823SKP Singh * Set this to 0 to avoid confusing the program. 1640ae240823SKP Singh */ 1641ae240823SKP Singh emit_mov_imm32(&prog, false, BPF_REG_0, 0); 1642ae240823SKP Singh emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8); 1643ae240823SKP Singh for (i = 0; i < tp->nr_progs; i++) { 1644ae240823SKP Singh if (invoke_bpf_prog(m, &prog, tp->progs[i], stack_size, true)) 1645ae240823SKP Singh return -EINVAL; 1646ae240823SKP Singh 164713fac1d8SAlexei Starovoitov /* mod_ret prog stored return value into [rbp - 8]. Emit: 164813fac1d8SAlexei Starovoitov * if (*(u64 *)(rbp - 8) != 0) 1649ae240823SKP Singh * goto do_fexit; 1650ae240823SKP Singh */ 165113fac1d8SAlexei Starovoitov /* cmp QWORD PTR [rbp - 0x8], 0x0 */ 165213fac1d8SAlexei Starovoitov EMIT4(0x48, 0x83, 0x7d, 0xf8); EMIT1(0x00); 1653ae240823SKP Singh 1654ae240823SKP Singh /* Save the location of the branch and Generate 6 nops 1655ae240823SKP Singh * (4 bytes for an offset and 2 bytes for the jump) These nops 1656ae240823SKP Singh * are replaced with a conditional jump once do_fexit (i.e. the 1657ae240823SKP Singh * start of the fexit invocation) is finalized. 1658ae240823SKP Singh */ 1659ae240823SKP Singh branches[i] = prog; 1660ae240823SKP Singh emit_nops(&prog, 4 + 2); 1661ae240823SKP Singh } 1662ae240823SKP Singh 1663ae240823SKP Singh *pprog = prog; 1664ae240823SKP Singh return 0; 1665ae240823SKP Singh } 1666ae240823SKP Singh 1667fec56f58SAlexei Starovoitov /* Example: 1668fec56f58SAlexei Starovoitov * __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev); 1669fec56f58SAlexei Starovoitov * its 'struct btf_func_model' will be nr_args=2 1670fec56f58SAlexei Starovoitov * The assembly code when eth_type_trans is executing after trampoline: 1671fec56f58SAlexei Starovoitov * 1672fec56f58SAlexei Starovoitov * push rbp 1673fec56f58SAlexei Starovoitov * mov rbp, rsp 1674fec56f58SAlexei Starovoitov * sub rsp, 16 // space for skb and dev 1675fec56f58SAlexei Starovoitov * push rbx // temp regs to pass start time 1676fec56f58SAlexei Starovoitov * mov qword ptr [rbp - 16], rdi // save skb pointer to stack 1677fec56f58SAlexei Starovoitov * mov qword ptr [rbp - 8], rsi // save dev pointer to stack 1678fec56f58SAlexei Starovoitov * call __bpf_prog_enter // rcu_read_lock and preempt_disable 1679fec56f58SAlexei Starovoitov * mov rbx, rax // remember start time in bpf stats are enabled 1680fec56f58SAlexei Starovoitov * lea rdi, [rbp - 16] // R1==ctx of bpf prog 1681fec56f58SAlexei Starovoitov * call addr_of_jited_FENTRY_prog 1682fec56f58SAlexei Starovoitov * movabsq rdi, 64bit_addr_of_struct_bpf_prog // unused if bpf stats are off 1683fec56f58SAlexei Starovoitov * mov rsi, rbx // prog start time 1684fec56f58SAlexei Starovoitov * call __bpf_prog_exit // rcu_read_unlock, preempt_enable and stats math 1685fec56f58SAlexei Starovoitov * mov rdi, qword ptr [rbp - 16] // restore skb pointer from stack 1686fec56f58SAlexei Starovoitov * mov rsi, qword ptr [rbp - 8] // restore dev pointer from stack 1687fec56f58SAlexei Starovoitov * pop rbx 1688fec56f58SAlexei Starovoitov * leave 1689fec56f58SAlexei Starovoitov * ret 1690fec56f58SAlexei Starovoitov * 1691fec56f58SAlexei Starovoitov * eth_type_trans has 5 byte nop at the beginning. These 5 bytes will be 1692fec56f58SAlexei Starovoitov * replaced with 'call generated_bpf_trampoline'. When it returns 1693fec56f58SAlexei Starovoitov * eth_type_trans will continue executing with original skb and dev pointers. 1694fec56f58SAlexei Starovoitov * 1695fec56f58SAlexei Starovoitov * The assembly code when eth_type_trans is called from trampoline: 1696fec56f58SAlexei Starovoitov * 1697fec56f58SAlexei Starovoitov * push rbp 1698fec56f58SAlexei Starovoitov * mov rbp, rsp 1699fec56f58SAlexei Starovoitov * sub rsp, 24 // space for skb, dev, return value 1700fec56f58SAlexei Starovoitov * push rbx // temp regs to pass start time 1701fec56f58SAlexei Starovoitov * mov qword ptr [rbp - 24], rdi // save skb pointer to stack 1702fec56f58SAlexei Starovoitov * mov qword ptr [rbp - 16], rsi // save dev pointer to stack 1703fec56f58SAlexei Starovoitov * call __bpf_prog_enter // rcu_read_lock and preempt_disable 1704fec56f58SAlexei Starovoitov * mov rbx, rax // remember start time if bpf stats are enabled 1705fec56f58SAlexei Starovoitov * lea rdi, [rbp - 24] // R1==ctx of bpf prog 1706fec56f58SAlexei Starovoitov * call addr_of_jited_FENTRY_prog // bpf prog can access skb and dev 1707fec56f58SAlexei Starovoitov * movabsq rdi, 64bit_addr_of_struct_bpf_prog // unused if bpf stats are off 1708fec56f58SAlexei Starovoitov * mov rsi, rbx // prog start time 1709fec56f58SAlexei Starovoitov * call __bpf_prog_exit // rcu_read_unlock, preempt_enable and stats math 1710fec56f58SAlexei Starovoitov * mov rdi, qword ptr [rbp - 24] // restore skb pointer from stack 1711fec56f58SAlexei Starovoitov * mov rsi, qword ptr [rbp - 16] // restore dev pointer from stack 1712fec56f58SAlexei Starovoitov * call eth_type_trans+5 // execute body of eth_type_trans 1713fec56f58SAlexei Starovoitov * mov qword ptr [rbp - 8], rax // save return value 1714fec56f58SAlexei Starovoitov * call __bpf_prog_enter // rcu_read_lock and preempt_disable 1715fec56f58SAlexei Starovoitov * mov rbx, rax // remember start time in bpf stats are enabled 1716fec56f58SAlexei Starovoitov * lea rdi, [rbp - 24] // R1==ctx of bpf prog 1717fec56f58SAlexei Starovoitov * call addr_of_jited_FEXIT_prog // bpf prog can access skb, dev, return value 1718fec56f58SAlexei Starovoitov * movabsq rdi, 64bit_addr_of_struct_bpf_prog // unused if bpf stats are off 1719fec56f58SAlexei Starovoitov * mov rsi, rbx // prog start time 1720fec56f58SAlexei Starovoitov * call __bpf_prog_exit // rcu_read_unlock, preempt_enable and stats math 1721fec56f58SAlexei Starovoitov * mov rax, qword ptr [rbp - 8] // restore eth_type_trans's return value 1722fec56f58SAlexei Starovoitov * pop rbx 1723fec56f58SAlexei Starovoitov * leave 1724fec56f58SAlexei Starovoitov * add rsp, 8 // skip eth_type_trans's frame 1725fec56f58SAlexei Starovoitov * ret // return to its caller 1726fec56f58SAlexei Starovoitov */ 172785d33df3SMartin KaFai Lau int arch_prepare_bpf_trampoline(void *image, void *image_end, 172885d33df3SMartin KaFai Lau const struct btf_func_model *m, u32 flags, 172988fd9e53SKP Singh struct bpf_tramp_progs *tprogs, 1730fec56f58SAlexei Starovoitov void *orig_call) 1731fec56f58SAlexei Starovoitov { 1732ae240823SKP Singh int ret, i, cnt = 0, nr_args = m->nr_args; 1733fec56f58SAlexei Starovoitov int stack_size = nr_args * 8; 173488fd9e53SKP Singh struct bpf_tramp_progs *fentry = &tprogs[BPF_TRAMP_FENTRY]; 173588fd9e53SKP Singh struct bpf_tramp_progs *fexit = &tprogs[BPF_TRAMP_FEXIT]; 1736ae240823SKP Singh struct bpf_tramp_progs *fmod_ret = &tprogs[BPF_TRAMP_MODIFY_RETURN]; 1737ae240823SKP Singh u8 **branches = NULL; 1738fec56f58SAlexei Starovoitov u8 *prog; 1739fec56f58SAlexei Starovoitov 1740fec56f58SAlexei Starovoitov /* x86-64 supports up to 6 arguments. 7+ can be added in the future */ 1741fec56f58SAlexei Starovoitov if (nr_args > 6) 1742fec56f58SAlexei Starovoitov return -ENOTSUPP; 1743fec56f58SAlexei Starovoitov 1744fec56f58SAlexei Starovoitov if ((flags & BPF_TRAMP_F_RESTORE_REGS) && 1745fec56f58SAlexei Starovoitov (flags & BPF_TRAMP_F_SKIP_FRAME)) 1746fec56f58SAlexei Starovoitov return -EINVAL; 1747fec56f58SAlexei Starovoitov 1748fec56f58SAlexei Starovoitov if (flags & BPF_TRAMP_F_CALL_ORIG) 1749fec56f58SAlexei Starovoitov stack_size += 8; /* room for return value of orig_call */ 1750fec56f58SAlexei Starovoitov 1751fec56f58SAlexei Starovoitov if (flags & BPF_TRAMP_F_SKIP_FRAME) 1752fec56f58SAlexei Starovoitov /* skip patched call instruction and point orig_call to actual 1753fec56f58SAlexei Starovoitov * body of the kernel function. 1754fec56f58SAlexei Starovoitov */ 17554b3da77bSDaniel Borkmann orig_call += X86_PATCH_SIZE; 1756fec56f58SAlexei Starovoitov 1757fec56f58SAlexei Starovoitov prog = image; 1758fec56f58SAlexei Starovoitov 1759fec56f58SAlexei Starovoitov EMIT1(0x55); /* push rbp */ 1760fec56f58SAlexei Starovoitov EMIT3(0x48, 0x89, 0xE5); /* mov rbp, rsp */ 1761fec56f58SAlexei Starovoitov EMIT4(0x48, 0x83, 0xEC, stack_size); /* sub rsp, stack_size */ 1762fec56f58SAlexei Starovoitov EMIT1(0x53); /* push rbx */ 1763fec56f58SAlexei Starovoitov 1764fec56f58SAlexei Starovoitov save_regs(m, &prog, nr_args, stack_size); 1765fec56f58SAlexei Starovoitov 176688fd9e53SKP Singh if (fentry->nr_progs) 176788fd9e53SKP Singh if (invoke_bpf(m, &prog, fentry, stack_size)) 1768fec56f58SAlexei Starovoitov return -EINVAL; 1769fec56f58SAlexei Starovoitov 1770ae240823SKP Singh if (fmod_ret->nr_progs) { 1771ae240823SKP Singh branches = kcalloc(fmod_ret->nr_progs, sizeof(u8 *), 1772ae240823SKP Singh GFP_KERNEL); 1773ae240823SKP Singh if (!branches) 1774ae240823SKP Singh return -ENOMEM; 1775ae240823SKP Singh 1776ae240823SKP Singh if (invoke_bpf_mod_ret(m, &prog, fmod_ret, stack_size, 1777ae240823SKP Singh branches)) { 1778ae240823SKP Singh ret = -EINVAL; 1779ae240823SKP Singh goto cleanup; 1780ae240823SKP Singh } 1781ae240823SKP Singh } 1782ae240823SKP Singh 1783fec56f58SAlexei Starovoitov if (flags & BPF_TRAMP_F_CALL_ORIG) { 1784ae240823SKP Singh if (fentry->nr_progs || fmod_ret->nr_progs) 1785fec56f58SAlexei Starovoitov restore_regs(m, &prog, nr_args, stack_size); 1786fec56f58SAlexei Starovoitov 1787fec56f58SAlexei Starovoitov /* call original function */ 1788ae240823SKP Singh if (emit_call(&prog, orig_call, prog)) { 1789ae240823SKP Singh ret = -EINVAL; 1790ae240823SKP Singh goto cleanup; 1791ae240823SKP Singh } 1792fec56f58SAlexei Starovoitov /* remember return value in a stack for bpf prog to access */ 1793fec56f58SAlexei Starovoitov emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8); 1794fec56f58SAlexei Starovoitov } 1795fec56f58SAlexei Starovoitov 1796ae240823SKP Singh if (fmod_ret->nr_progs) { 1797ae240823SKP Singh /* From Intel 64 and IA-32 Architectures Optimization 1798ae240823SKP Singh * Reference Manual, 3.4.1.4 Code Alignment, Assembly/Compiler 1799ae240823SKP Singh * Coding Rule 11: All branch targets should be 16-byte 1800ae240823SKP Singh * aligned. 1801ae240823SKP Singh */ 1802ae240823SKP Singh emit_align(&prog, 16); 1803ae240823SKP Singh /* Update the branches saved in invoke_bpf_mod_ret with the 1804ae240823SKP Singh * aligned address of do_fexit. 1805ae240823SKP Singh */ 1806ae240823SKP Singh for (i = 0; i < fmod_ret->nr_progs; i++) 1807ae240823SKP Singh emit_cond_near_jump(&branches[i], prog, branches[i], 1808ae240823SKP Singh X86_JNE); 1809ae240823SKP Singh } 1810ae240823SKP Singh 181188fd9e53SKP Singh if (fexit->nr_progs) 1812ae240823SKP Singh if (invoke_bpf(m, &prog, fexit, stack_size)) { 1813ae240823SKP Singh ret = -EINVAL; 1814ae240823SKP Singh goto cleanup; 1815ae240823SKP Singh } 1816fec56f58SAlexei Starovoitov 1817fec56f58SAlexei Starovoitov if (flags & BPF_TRAMP_F_RESTORE_REGS) 1818fec56f58SAlexei Starovoitov restore_regs(m, &prog, nr_args, stack_size); 1819fec56f58SAlexei Starovoitov 1820ae240823SKP Singh /* This needs to be done regardless. If there were fmod_ret programs, 1821ae240823SKP Singh * the return value is only updated on the stack and still needs to be 1822ae240823SKP Singh * restored to R0. 1823ae240823SKP Singh */ 1824fec56f58SAlexei Starovoitov if (flags & BPF_TRAMP_F_CALL_ORIG) 1825fec56f58SAlexei Starovoitov /* restore original return value back into RAX */ 1826fec56f58SAlexei Starovoitov emit_ldx(&prog, BPF_DW, BPF_REG_0, BPF_REG_FP, -8); 1827fec56f58SAlexei Starovoitov 1828fec56f58SAlexei Starovoitov EMIT1(0x5B); /* pop rbx */ 1829fec56f58SAlexei Starovoitov EMIT1(0xC9); /* leave */ 1830fec56f58SAlexei Starovoitov if (flags & BPF_TRAMP_F_SKIP_FRAME) 1831fec56f58SAlexei Starovoitov /* skip our return address and return to parent */ 1832fec56f58SAlexei Starovoitov EMIT4(0x48, 0x83, 0xC4, 8); /* add rsp, 8 */ 1833fec56f58SAlexei Starovoitov EMIT1(0xC3); /* ret */ 183485d33df3SMartin KaFai Lau /* Make sure the trampoline generation logic doesn't overflow */ 1835ae240823SKP Singh if (WARN_ON_ONCE(prog > (u8 *)image_end - BPF_INSN_SAFETY)) { 1836ae240823SKP Singh ret = -EFAULT; 1837ae240823SKP Singh goto cleanup; 1838ae240823SKP Singh } 1839ae240823SKP Singh ret = prog - (u8 *)image; 1840ae240823SKP Singh 1841ae240823SKP Singh cleanup: 1842ae240823SKP Singh kfree(branches); 1843ae240823SKP Singh return ret; 1844fec56f58SAlexei Starovoitov } 1845fec56f58SAlexei Starovoitov 184675ccbef6SBjörn Töpel static int emit_fallback_jump(u8 **pprog) 184775ccbef6SBjörn Töpel { 184875ccbef6SBjörn Töpel u8 *prog = *pprog; 184975ccbef6SBjörn Töpel int err = 0; 185075ccbef6SBjörn Töpel 185175ccbef6SBjörn Töpel #ifdef CONFIG_RETPOLINE 185275ccbef6SBjörn Töpel /* Note that this assumes the the compiler uses external 185375ccbef6SBjörn Töpel * thunks for indirect calls. Both clang and GCC use the same 185475ccbef6SBjörn Töpel * naming convention for external thunks. 185575ccbef6SBjörn Töpel */ 185675ccbef6SBjörn Töpel err = emit_jump(&prog, __x86_indirect_thunk_rdx, prog); 185775ccbef6SBjörn Töpel #else 185875ccbef6SBjörn Töpel int cnt = 0; 185975ccbef6SBjörn Töpel 186075ccbef6SBjörn Töpel EMIT2(0xFF, 0xE2); /* jmp rdx */ 186175ccbef6SBjörn Töpel #endif 186275ccbef6SBjörn Töpel *pprog = prog; 186375ccbef6SBjörn Töpel return err; 186475ccbef6SBjörn Töpel } 186575ccbef6SBjörn Töpel 186675ccbef6SBjörn Töpel static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs) 186775ccbef6SBjörn Töpel { 18687e639208SKP Singh u8 *jg_reloc, *prog = *pprog; 186975ccbef6SBjörn Töpel int pivot, err, jg_bytes = 1, cnt = 0; 187075ccbef6SBjörn Töpel s64 jg_offset; 187175ccbef6SBjörn Töpel 187275ccbef6SBjörn Töpel if (a == b) { 187375ccbef6SBjörn Töpel /* Leaf node of recursion, i.e. not a range of indices 187475ccbef6SBjörn Töpel * anymore. 187575ccbef6SBjörn Töpel */ 187675ccbef6SBjörn Töpel EMIT1(add_1mod(0x48, BPF_REG_3)); /* cmp rdx,func */ 187775ccbef6SBjörn Töpel if (!is_simm32(progs[a])) 187875ccbef6SBjörn Töpel return -1; 187975ccbef6SBjörn Töpel EMIT2_off32(0x81, add_1reg(0xF8, BPF_REG_3), 188075ccbef6SBjörn Töpel progs[a]); 188175ccbef6SBjörn Töpel err = emit_cond_near_jump(&prog, /* je func */ 188275ccbef6SBjörn Töpel (void *)progs[a], prog, 188375ccbef6SBjörn Töpel X86_JE); 188475ccbef6SBjörn Töpel if (err) 188575ccbef6SBjörn Töpel return err; 188675ccbef6SBjörn Töpel 188775ccbef6SBjörn Töpel err = emit_fallback_jump(&prog); /* jmp thunk/indirect */ 188875ccbef6SBjörn Töpel if (err) 188975ccbef6SBjörn Töpel return err; 189075ccbef6SBjörn Töpel 189175ccbef6SBjörn Töpel *pprog = prog; 189275ccbef6SBjörn Töpel return 0; 189375ccbef6SBjörn Töpel } 189475ccbef6SBjörn Töpel 189575ccbef6SBjörn Töpel /* Not a leaf node, so we pivot, and recursively descend into 189675ccbef6SBjörn Töpel * the lower and upper ranges. 189775ccbef6SBjörn Töpel */ 189875ccbef6SBjörn Töpel pivot = (b - a) / 2; 189975ccbef6SBjörn Töpel EMIT1(add_1mod(0x48, BPF_REG_3)); /* cmp rdx,func */ 190075ccbef6SBjörn Töpel if (!is_simm32(progs[a + pivot])) 190175ccbef6SBjörn Töpel return -1; 190275ccbef6SBjörn Töpel EMIT2_off32(0x81, add_1reg(0xF8, BPF_REG_3), progs[a + pivot]); 190375ccbef6SBjörn Töpel 190475ccbef6SBjörn Töpel if (pivot > 2) { /* jg upper_part */ 190575ccbef6SBjörn Töpel /* Require near jump. */ 190675ccbef6SBjörn Töpel jg_bytes = 4; 190775ccbef6SBjörn Töpel EMIT2_off32(0x0F, X86_JG + 0x10, 0); 190875ccbef6SBjörn Töpel } else { 190975ccbef6SBjörn Töpel EMIT2(X86_JG, 0); 191075ccbef6SBjörn Töpel } 191175ccbef6SBjörn Töpel jg_reloc = prog; 191275ccbef6SBjörn Töpel 191375ccbef6SBjörn Töpel err = emit_bpf_dispatcher(&prog, a, a + pivot, /* emit lower_part */ 191475ccbef6SBjörn Töpel progs); 191575ccbef6SBjörn Töpel if (err) 191675ccbef6SBjörn Töpel return err; 191775ccbef6SBjörn Töpel 1918116eb788SBjörn Töpel /* From Intel 64 and IA-32 Architectures Optimization 1919116eb788SBjörn Töpel * Reference Manual, 3.4.1.4 Code Alignment, Assembly/Compiler 1920116eb788SBjörn Töpel * Coding Rule 11: All branch targets should be 16-byte 1921116eb788SBjörn Töpel * aligned. 1922116eb788SBjörn Töpel */ 19237e639208SKP Singh emit_align(&prog, 16); 192475ccbef6SBjörn Töpel jg_offset = prog - jg_reloc; 192575ccbef6SBjörn Töpel emit_code(jg_reloc - jg_bytes, jg_offset, jg_bytes); 192675ccbef6SBjörn Töpel 192775ccbef6SBjörn Töpel err = emit_bpf_dispatcher(&prog, a + pivot + 1, /* emit upper_part */ 192875ccbef6SBjörn Töpel b, progs); 192975ccbef6SBjörn Töpel if (err) 193075ccbef6SBjörn Töpel return err; 193175ccbef6SBjörn Töpel 193275ccbef6SBjörn Töpel *pprog = prog; 193375ccbef6SBjörn Töpel return 0; 193475ccbef6SBjörn Töpel } 193575ccbef6SBjörn Töpel 193675ccbef6SBjörn Töpel static int cmp_ips(const void *a, const void *b) 193775ccbef6SBjörn Töpel { 193875ccbef6SBjörn Töpel const s64 *ipa = a; 193975ccbef6SBjörn Töpel const s64 *ipb = b; 194075ccbef6SBjörn Töpel 194175ccbef6SBjörn Töpel if (*ipa > *ipb) 194275ccbef6SBjörn Töpel return 1; 194375ccbef6SBjörn Töpel if (*ipa < *ipb) 194475ccbef6SBjörn Töpel return -1; 194575ccbef6SBjörn Töpel return 0; 194675ccbef6SBjörn Töpel } 194775ccbef6SBjörn Töpel 194875ccbef6SBjörn Töpel int arch_prepare_bpf_dispatcher(void *image, s64 *funcs, int num_funcs) 194975ccbef6SBjörn Töpel { 195075ccbef6SBjörn Töpel u8 *prog = image; 195175ccbef6SBjörn Töpel 195275ccbef6SBjörn Töpel sort(funcs, num_funcs, sizeof(funcs[0]), cmp_ips, NULL); 195375ccbef6SBjörn Töpel return emit_bpf_dispatcher(&prog, 0, num_funcs - 1, funcs); 195475ccbef6SBjörn Töpel } 195575ccbef6SBjörn Töpel 19561c2a088aSAlexei Starovoitov struct x64_jit_data { 19571c2a088aSAlexei Starovoitov struct bpf_binary_header *header; 19581c2a088aSAlexei Starovoitov int *addrs; 19591c2a088aSAlexei Starovoitov u8 *image; 19601c2a088aSAlexei Starovoitov int proglen; 19611c2a088aSAlexei Starovoitov struct jit_context ctx; 19621c2a088aSAlexei Starovoitov }; 19631c2a088aSAlexei Starovoitov 1964d1c55ab5SDaniel Borkmann struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) 196562258278SAlexei Starovoitov { 1966f3c2af7bSAlexei Starovoitov struct bpf_binary_header *header = NULL; 1967959a7579SDaniel Borkmann struct bpf_prog *tmp, *orig_prog = prog; 19681c2a088aSAlexei Starovoitov struct x64_jit_data *jit_data; 1969f3c2af7bSAlexei Starovoitov int proglen, oldproglen = 0; 1970f3c2af7bSAlexei Starovoitov struct jit_context ctx = {}; 1971959a7579SDaniel Borkmann bool tmp_blinded = false; 19721c2a088aSAlexei Starovoitov bool extra_pass = false; 1973f3c2af7bSAlexei Starovoitov u8 *image = NULL; 1974f3c2af7bSAlexei Starovoitov int *addrs; 1975f3c2af7bSAlexei Starovoitov int pass; 1976f3c2af7bSAlexei Starovoitov int i; 1977f3c2af7bSAlexei Starovoitov 197860b58afcSAlexei Starovoitov if (!prog->jit_requested) 1979959a7579SDaniel Borkmann return orig_prog; 1980959a7579SDaniel Borkmann 1981959a7579SDaniel Borkmann tmp = bpf_jit_blind_constants(prog); 1982a2c7a983SIngo Molnar /* 1983a2c7a983SIngo Molnar * If blinding was requested and we failed during blinding, 1984959a7579SDaniel Borkmann * we must fall back to the interpreter. 1985959a7579SDaniel Borkmann */ 1986959a7579SDaniel Borkmann if (IS_ERR(tmp)) 1987959a7579SDaniel Borkmann return orig_prog; 1988959a7579SDaniel Borkmann if (tmp != prog) { 1989959a7579SDaniel Borkmann tmp_blinded = true; 1990959a7579SDaniel Borkmann prog = tmp; 1991959a7579SDaniel Borkmann } 1992f3c2af7bSAlexei Starovoitov 19931c2a088aSAlexei Starovoitov jit_data = prog->aux->jit_data; 19941c2a088aSAlexei Starovoitov if (!jit_data) { 19951c2a088aSAlexei Starovoitov jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); 19961c2a088aSAlexei Starovoitov if (!jit_data) { 19971c2a088aSAlexei Starovoitov prog = orig_prog; 19981c2a088aSAlexei Starovoitov goto out; 19991c2a088aSAlexei Starovoitov } 20001c2a088aSAlexei Starovoitov prog->aux->jit_data = jit_data; 20011c2a088aSAlexei Starovoitov } 20021c2a088aSAlexei Starovoitov addrs = jit_data->addrs; 20031c2a088aSAlexei Starovoitov if (addrs) { 20041c2a088aSAlexei Starovoitov ctx = jit_data->ctx; 20051c2a088aSAlexei Starovoitov oldproglen = jit_data->proglen; 20061c2a088aSAlexei Starovoitov image = jit_data->image; 20071c2a088aSAlexei Starovoitov header = jit_data->header; 20081c2a088aSAlexei Starovoitov extra_pass = true; 20091c2a088aSAlexei Starovoitov goto skip_init_addrs; 20101c2a088aSAlexei Starovoitov } 20117c2e988fSAlexei Starovoitov addrs = kmalloc_array(prog->len + 1, sizeof(*addrs), GFP_KERNEL); 2012959a7579SDaniel Borkmann if (!addrs) { 2013959a7579SDaniel Borkmann prog = orig_prog; 20141c2a088aSAlexei Starovoitov goto out_addrs; 2015959a7579SDaniel Borkmann } 2016f3c2af7bSAlexei Starovoitov 2017a2c7a983SIngo Molnar /* 2018a2c7a983SIngo Molnar * Before first pass, make a rough estimation of addrs[] 2019a2c7a983SIngo Molnar * each BPF instruction is translated to less than 64 bytes 2020f3c2af7bSAlexei Starovoitov */ 20217c2e988fSAlexei Starovoitov for (proglen = 0, i = 0; i <= prog->len; i++) { 2022f3c2af7bSAlexei Starovoitov proglen += 64; 2023f3c2af7bSAlexei Starovoitov addrs[i] = proglen; 2024f3c2af7bSAlexei Starovoitov } 2025f3c2af7bSAlexei Starovoitov ctx.cleanup_addr = proglen; 20261c2a088aSAlexei Starovoitov skip_init_addrs: 2027f3c2af7bSAlexei Starovoitov 2028a2c7a983SIngo Molnar /* 2029a2c7a983SIngo Molnar * JITed image shrinks with every pass and the loop iterates 2030a2c7a983SIngo Molnar * until the image stops shrinking. Very large BPF programs 20313f7352bfSAlexei Starovoitov * may converge on the last pass. In such case do one more 2032a2c7a983SIngo Molnar * pass to emit the final image. 20333f7352bfSAlexei Starovoitov */ 20346007b080SDaniel Borkmann for (pass = 0; pass < 20 || image; pass++) { 2035f3c2af7bSAlexei Starovoitov proglen = do_jit(prog, addrs, image, oldproglen, &ctx); 2036f3c2af7bSAlexei Starovoitov if (proglen <= 0) { 20373aab8884SDaniel Borkmann out_image: 2038f3c2af7bSAlexei Starovoitov image = NULL; 2039f3c2af7bSAlexei Starovoitov if (header) 2040738cbe72SDaniel Borkmann bpf_jit_binary_free(header); 2041959a7579SDaniel Borkmann prog = orig_prog; 2042959a7579SDaniel Borkmann goto out_addrs; 2043f3c2af7bSAlexei Starovoitov } 20440a14842fSEric Dumazet if (image) { 2045e0ee9c12SAlexei Starovoitov if (proglen != oldproglen) { 2046f3c2af7bSAlexei Starovoitov pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", 2047f3c2af7bSAlexei Starovoitov proglen, oldproglen); 20483aab8884SDaniel Borkmann goto out_image; 2049e0ee9c12SAlexei Starovoitov } 20500a14842fSEric Dumazet break; 20510a14842fSEric Dumazet } 20520a14842fSEric Dumazet if (proglen == oldproglen) { 20533dec541bSAlexei Starovoitov /* 20543dec541bSAlexei Starovoitov * The number of entries in extable is the number of BPF_LDX 20553dec541bSAlexei Starovoitov * insns that access kernel memory via "pointer to BTF type". 20563dec541bSAlexei Starovoitov * The verifier changed their opcode from LDX|MEM|size 20573dec541bSAlexei Starovoitov * to LDX|PROBE_MEM|size to make JITing easier. 20583dec541bSAlexei Starovoitov */ 20593dec541bSAlexei Starovoitov u32 align = __alignof__(struct exception_table_entry); 20603dec541bSAlexei Starovoitov u32 extable_size = prog->aux->num_exentries * 20613dec541bSAlexei Starovoitov sizeof(struct exception_table_entry); 20623dec541bSAlexei Starovoitov 20633dec541bSAlexei Starovoitov /* allocate module memory for x86 insns and extable */ 20643dec541bSAlexei Starovoitov header = bpf_jit_binary_alloc(roundup(proglen, align) + extable_size, 20653dec541bSAlexei Starovoitov &image, align, jit_fill_hole); 2066959a7579SDaniel Borkmann if (!header) { 2067959a7579SDaniel Borkmann prog = orig_prog; 2068959a7579SDaniel Borkmann goto out_addrs; 2069959a7579SDaniel Borkmann } 20703dec541bSAlexei Starovoitov prog->aux->extable = (void *) image + roundup(proglen, align); 20710a14842fSEric Dumazet } 20720a14842fSEric Dumazet oldproglen = proglen; 20736007b080SDaniel Borkmann cond_resched(); 20740a14842fSEric Dumazet } 207579617801SDaniel Borkmann 20760a14842fSEric Dumazet if (bpf_jit_enable > 1) 2077485d6511SDaniel Borkmann bpf_jit_dump(prog->len, proglen, pass + 1, image); 20780a14842fSEric Dumazet 20790a14842fSEric Dumazet if (image) { 20801c2a088aSAlexei Starovoitov if (!prog->is_func || extra_pass) { 2081428d5df1SDaniel Borkmann bpf_tail_call_direct_fixup(prog); 20829d876e79SDaniel Borkmann bpf_jit_binary_lock_ro(header); 20831c2a088aSAlexei Starovoitov } else { 20841c2a088aSAlexei Starovoitov jit_data->addrs = addrs; 20851c2a088aSAlexei Starovoitov jit_data->ctx = ctx; 20861c2a088aSAlexei Starovoitov jit_data->proglen = proglen; 20871c2a088aSAlexei Starovoitov jit_data->image = image; 20881c2a088aSAlexei Starovoitov jit_data->header = header; 20891c2a088aSAlexei Starovoitov } 2090f3c2af7bSAlexei Starovoitov prog->bpf_func = (void *)image; 2091a91263d5SDaniel Borkmann prog->jited = 1; 2092783d28ddSMartin KaFai Lau prog->jited_len = proglen; 20939d5ecb09SDaniel Borkmann } else { 20949d5ecb09SDaniel Borkmann prog = orig_prog; 20950a14842fSEric Dumazet } 2096959a7579SDaniel Borkmann 209739f56ca9SDaniel Borkmann if (!image || !prog->is_func || extra_pass) { 2098c454a46bSMartin KaFai Lau if (image) 20997c2e988fSAlexei Starovoitov bpf_prog_fill_jited_linfo(prog, addrs + 1); 2100959a7579SDaniel Borkmann out_addrs: 21010a14842fSEric Dumazet kfree(addrs); 21021c2a088aSAlexei Starovoitov kfree(jit_data); 21031c2a088aSAlexei Starovoitov prog->aux->jit_data = NULL; 21041c2a088aSAlexei Starovoitov } 2105959a7579SDaniel Borkmann out: 2106959a7579SDaniel Borkmann if (tmp_blinded) 2107959a7579SDaniel Borkmann bpf_jit_prog_release_other(prog, prog == orig_prog ? 2108959a7579SDaniel Borkmann tmp : orig_prog); 2109d1c55ab5SDaniel Borkmann return prog; 21100a14842fSEric Dumazet } 2111