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 */ 2844d0b8c0bSMaciej Fijalkowski if (stack_depth) 285fe8d9571SAlexei Starovoitov EMIT3_off32(0x48, 0x81, 0xEC, round_up(stack_depth, 8)); 286ebf7d1f5SMaciej Fijalkowski if (tail_call_reachable) 287ebf7d1f5SMaciej Fijalkowski EMIT1(0x50); /* push rax */ 288b52f00e6SAlexei Starovoitov *pprog = prog; 289b52f00e6SAlexei Starovoitov } 290b52f00e6SAlexei Starovoitov 291428d5df1SDaniel Borkmann static int emit_patch(u8 **pprog, void *func, void *ip, u8 opcode) 292428d5df1SDaniel Borkmann { 293428d5df1SDaniel Borkmann u8 *prog = *pprog; 294428d5df1SDaniel Borkmann int cnt = 0; 295428d5df1SDaniel Borkmann s64 offset; 296428d5df1SDaniel Borkmann 297428d5df1SDaniel Borkmann offset = func - (ip + X86_PATCH_SIZE); 298428d5df1SDaniel Borkmann if (!is_simm32(offset)) { 299428d5df1SDaniel Borkmann pr_err("Target call %p is out of range\n", func); 300428d5df1SDaniel Borkmann return -ERANGE; 301428d5df1SDaniel Borkmann } 302428d5df1SDaniel Borkmann EMIT1_off32(opcode, offset); 303428d5df1SDaniel Borkmann *pprog = prog; 304428d5df1SDaniel Borkmann return 0; 305428d5df1SDaniel Borkmann } 306428d5df1SDaniel Borkmann 307428d5df1SDaniel Borkmann static int emit_call(u8 **pprog, void *func, void *ip) 308428d5df1SDaniel Borkmann { 309428d5df1SDaniel Borkmann return emit_patch(pprog, func, ip, 0xE8); 310428d5df1SDaniel Borkmann } 311428d5df1SDaniel Borkmann 312428d5df1SDaniel Borkmann static int emit_jump(u8 **pprog, void *func, void *ip) 313428d5df1SDaniel Borkmann { 314428d5df1SDaniel Borkmann return emit_patch(pprog, func, ip, 0xE9); 315428d5df1SDaniel Borkmann } 316428d5df1SDaniel Borkmann 317428d5df1SDaniel Borkmann static int __bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, 318428d5df1SDaniel Borkmann void *old_addr, void *new_addr, 319428d5df1SDaniel Borkmann const bool text_live) 320428d5df1SDaniel Borkmann { 321428d5df1SDaniel Borkmann const u8 *nop_insn = ideal_nops[NOP_ATOMIC5]; 322b553a6ecSDaniel Borkmann u8 old_insn[X86_PATCH_SIZE]; 323b553a6ecSDaniel Borkmann u8 new_insn[X86_PATCH_SIZE]; 324428d5df1SDaniel Borkmann u8 *prog; 325428d5df1SDaniel Borkmann int ret; 326428d5df1SDaniel Borkmann 327428d5df1SDaniel Borkmann memcpy(old_insn, nop_insn, X86_PATCH_SIZE); 328b553a6ecSDaniel Borkmann if (old_addr) { 329428d5df1SDaniel Borkmann prog = old_insn; 330b553a6ecSDaniel Borkmann ret = t == BPF_MOD_CALL ? 331b553a6ecSDaniel Borkmann emit_call(&prog, old_addr, ip) : 332b553a6ecSDaniel Borkmann emit_jump(&prog, old_addr, ip); 333428d5df1SDaniel Borkmann if (ret) 334428d5df1SDaniel Borkmann return ret; 335428d5df1SDaniel Borkmann } 336b553a6ecSDaniel Borkmann 337428d5df1SDaniel Borkmann memcpy(new_insn, nop_insn, X86_PATCH_SIZE); 338b553a6ecSDaniel Borkmann if (new_addr) { 339b553a6ecSDaniel Borkmann prog = new_insn; 340b553a6ecSDaniel Borkmann ret = t == BPF_MOD_CALL ? 341b553a6ecSDaniel Borkmann emit_call(&prog, new_addr, ip) : 342b553a6ecSDaniel Borkmann emit_jump(&prog, new_addr, ip); 343428d5df1SDaniel Borkmann if (ret) 344428d5df1SDaniel Borkmann return ret; 345428d5df1SDaniel Borkmann } 346428d5df1SDaniel Borkmann 347428d5df1SDaniel Borkmann ret = -EBUSY; 348428d5df1SDaniel Borkmann mutex_lock(&text_mutex); 349428d5df1SDaniel Borkmann if (memcmp(ip, old_insn, X86_PATCH_SIZE)) 350428d5df1SDaniel Borkmann goto out; 351ebf7d1f5SMaciej Fijalkowski ret = 1; 352b553a6ecSDaniel Borkmann if (memcmp(ip, new_insn, X86_PATCH_SIZE)) { 353428d5df1SDaniel Borkmann if (text_live) 354428d5df1SDaniel Borkmann text_poke_bp(ip, new_insn, X86_PATCH_SIZE, NULL); 355428d5df1SDaniel Borkmann else 356428d5df1SDaniel Borkmann memcpy(ip, new_insn, X86_PATCH_SIZE); 357428d5df1SDaniel Borkmann ret = 0; 358ebf7d1f5SMaciej Fijalkowski } 359428d5df1SDaniel Borkmann out: 360428d5df1SDaniel Borkmann mutex_unlock(&text_mutex); 361428d5df1SDaniel Borkmann return ret; 362428d5df1SDaniel Borkmann } 363428d5df1SDaniel Borkmann 364428d5df1SDaniel Borkmann int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, 365428d5df1SDaniel Borkmann void *old_addr, void *new_addr) 366428d5df1SDaniel Borkmann { 367428d5df1SDaniel Borkmann if (!is_kernel_text((long)ip) && 368428d5df1SDaniel Borkmann !is_bpf_text_address((long)ip)) 369428d5df1SDaniel Borkmann /* BPF poking in modules is not supported */ 370428d5df1SDaniel Borkmann return -EINVAL; 371428d5df1SDaniel Borkmann 372428d5df1SDaniel Borkmann return __bpf_arch_text_poke(ip, t, old_addr, new_addr, true); 373428d5df1SDaniel Borkmann } 374428d5df1SDaniel Borkmann 375ebf7d1f5SMaciej Fijalkowski static int get_pop_bytes(bool *callee_regs_used) 376ebf7d1f5SMaciej Fijalkowski { 377ebf7d1f5SMaciej Fijalkowski int bytes = 0; 378ebf7d1f5SMaciej Fijalkowski 379ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[3]) 380ebf7d1f5SMaciej Fijalkowski bytes += 2; 381ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[2]) 382ebf7d1f5SMaciej Fijalkowski bytes += 2; 383ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[1]) 384ebf7d1f5SMaciej Fijalkowski bytes += 2; 385ebf7d1f5SMaciej Fijalkowski if (callee_regs_used[0]) 386ebf7d1f5SMaciej Fijalkowski bytes += 1; 387ebf7d1f5SMaciej Fijalkowski 388ebf7d1f5SMaciej Fijalkowski return bytes; 389ebf7d1f5SMaciej Fijalkowski } 390ebf7d1f5SMaciej Fijalkowski 391a2c7a983SIngo Molnar /* 392a2c7a983SIngo Molnar * Generate the following code: 393a2c7a983SIngo Molnar * 394b52f00e6SAlexei Starovoitov * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... 395b52f00e6SAlexei Starovoitov * if (index >= array->map.max_entries) 396b52f00e6SAlexei Starovoitov * goto out; 397b52f00e6SAlexei Starovoitov * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) 398b52f00e6SAlexei Starovoitov * goto out; 3992a36f0b9SWang Nan * prog = array->ptrs[index]; 400b52f00e6SAlexei Starovoitov * if (prog == NULL) 401b52f00e6SAlexei Starovoitov * goto out; 402b52f00e6SAlexei Starovoitov * goto *(prog->bpf_func + prologue_size); 403b52f00e6SAlexei Starovoitov * out: 404b52f00e6SAlexei Starovoitov */ 405ebf7d1f5SMaciej Fijalkowski static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used, 406ebf7d1f5SMaciej Fijalkowski u32 stack_depth) 407b52f00e6SAlexei Starovoitov { 408ebf7d1f5SMaciej Fijalkowski int tcc_off = -4 - round_up(stack_depth, 8); 409b52f00e6SAlexei Starovoitov u8 *prog = *pprog; 410ebf7d1f5SMaciej Fijalkowski int pop_bytes = 0; 4114d0b8c0bSMaciej Fijalkowski int off1 = 42; 4124d0b8c0bSMaciej Fijalkowski int off2 = 31; 4134d0b8c0bSMaciej Fijalkowski int off3 = 9; 414b52f00e6SAlexei Starovoitov int cnt = 0; 415b52f00e6SAlexei Starovoitov 416ebf7d1f5SMaciej Fijalkowski /* count the additional bytes used for popping callee regs from stack 417ebf7d1f5SMaciej Fijalkowski * that need to be taken into account for each of the offsets that 418ebf7d1f5SMaciej Fijalkowski * are used for bailing out of the tail call 419ebf7d1f5SMaciej Fijalkowski */ 420ebf7d1f5SMaciej Fijalkowski pop_bytes = get_pop_bytes(callee_regs_used); 421ebf7d1f5SMaciej Fijalkowski off1 += pop_bytes; 422ebf7d1f5SMaciej Fijalkowski off2 += pop_bytes; 423ebf7d1f5SMaciej Fijalkowski off3 += pop_bytes; 424ebf7d1f5SMaciej Fijalkowski 4254d0b8c0bSMaciej Fijalkowski if (stack_depth) { 4264d0b8c0bSMaciej Fijalkowski off1 += 7; 4274d0b8c0bSMaciej Fijalkowski off2 += 7; 4284d0b8c0bSMaciej Fijalkowski off3 += 7; 4294d0b8c0bSMaciej Fijalkowski } 4304d0b8c0bSMaciej Fijalkowski 431a2c7a983SIngo Molnar /* 432a2c7a983SIngo Molnar * rdi - pointer to ctx 433b52f00e6SAlexei Starovoitov * rsi - pointer to bpf_array 434b52f00e6SAlexei Starovoitov * rdx - index in bpf_array 435b52f00e6SAlexei Starovoitov */ 436b52f00e6SAlexei Starovoitov 437a2c7a983SIngo Molnar /* 438a2c7a983SIngo Molnar * if (index >= array->map.max_entries) 439b52f00e6SAlexei Starovoitov * goto out; 440b52f00e6SAlexei Starovoitov */ 44190caccddSAlexei Starovoitov EMIT2(0x89, 0xD2); /* mov edx, edx */ 44290caccddSAlexei Starovoitov EMIT3(0x39, 0x56, /* cmp dword ptr [rsi + 16], edx */ 443b52f00e6SAlexei Starovoitov offsetof(struct bpf_array, map.max_entries)); 444ebf7d1f5SMaciej Fijalkowski #define OFFSET1 (off1 + RETPOLINE_RCX_BPF_JIT_SIZE) /* Number of bytes to jump */ 445b52f00e6SAlexei Starovoitov EMIT2(X86_JBE, OFFSET1); /* jbe out */ 446b52f00e6SAlexei Starovoitov 447a2c7a983SIngo Molnar /* 448a2c7a983SIngo Molnar * if (tail_call_cnt > MAX_TAIL_CALL_CNT) 449b52f00e6SAlexei Starovoitov * goto out; 450b52f00e6SAlexei Starovoitov */ 451ebf7d1f5SMaciej Fijalkowski EMIT2_off32(0x8B, 0x85, tcc_off); /* mov eax, dword ptr [rbp - tcc_off] */ 452b52f00e6SAlexei Starovoitov EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ 453ebf7d1f5SMaciej Fijalkowski #define OFFSET2 (off2 + RETPOLINE_RCX_BPF_JIT_SIZE) 454b52f00e6SAlexei Starovoitov EMIT2(X86_JA, OFFSET2); /* ja out */ 455b52f00e6SAlexei Starovoitov EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ 456ebf7d1f5SMaciej Fijalkowski EMIT2_off32(0x89, 0x85, tcc_off); /* mov dword ptr [rbp - tcc_off], eax */ 457b52f00e6SAlexei Starovoitov 4582a36f0b9SWang Nan /* prog = array->ptrs[index]; */ 4590d4ddce3SMaciej Fijalkowski EMIT4_off32(0x48, 0x8B, 0x8C, 0xD6, /* mov rcx, [rsi + rdx * 8 + offsetof(...)] */ 4602a36f0b9SWang Nan offsetof(struct bpf_array, ptrs)); 461b52f00e6SAlexei Starovoitov 462a2c7a983SIngo Molnar /* 463a2c7a983SIngo Molnar * if (prog == NULL) 464b52f00e6SAlexei Starovoitov * goto out; 465b52f00e6SAlexei Starovoitov */ 4660d4ddce3SMaciej Fijalkowski EMIT3(0x48, 0x85, 0xC9); /* test rcx,rcx */ 467ebf7d1f5SMaciej Fijalkowski #define OFFSET3 (off3 + RETPOLINE_RCX_BPF_JIT_SIZE) 468b52f00e6SAlexei Starovoitov EMIT2(X86_JE, OFFSET3); /* je out */ 469b52f00e6SAlexei Starovoitov 470ebf7d1f5SMaciej Fijalkowski *pprog = prog; 471ebf7d1f5SMaciej Fijalkowski pop_callee_regs(pprog, callee_regs_used); 472ebf7d1f5SMaciej Fijalkowski prog = *pprog; 473ebf7d1f5SMaciej Fijalkowski 474ebf7d1f5SMaciej Fijalkowski EMIT1(0x58); /* pop rax */ 4754d0b8c0bSMaciej Fijalkowski if (stack_depth) 476ebf7d1f5SMaciej Fijalkowski EMIT3_off32(0x48, 0x81, 0xC4, /* add rsp, sd */ 477ebf7d1f5SMaciej Fijalkowski round_up(stack_depth, 8)); 478ebf7d1f5SMaciej Fijalkowski 479ebf7d1f5SMaciej Fijalkowski /* goto *(prog->bpf_func + X86_TAIL_CALL_OFFSET); */ 4800d4ddce3SMaciej Fijalkowski EMIT4(0x48, 0x8B, 0x49, /* mov rcx, qword ptr [rcx + 32] */ 481b52f00e6SAlexei Starovoitov offsetof(struct bpf_prog, bpf_func)); 482ebf7d1f5SMaciej Fijalkowski EMIT4(0x48, 0x83, 0xC1, /* add rcx, X86_TAIL_CALL_OFFSET */ 483ebf7d1f5SMaciej Fijalkowski X86_TAIL_CALL_OFFSET); 484a2c7a983SIngo Molnar /* 4850d4ddce3SMaciej Fijalkowski * Now we're ready to jump into next BPF program 486b52f00e6SAlexei Starovoitov * rdi == ctx (1st arg) 487ebf7d1f5SMaciej Fijalkowski * rcx == prog->bpf_func + X86_TAIL_CALL_OFFSET 488b52f00e6SAlexei Starovoitov */ 4890d4ddce3SMaciej Fijalkowski RETPOLINE_RCX_BPF_JIT(); 490b52f00e6SAlexei Starovoitov 491b52f00e6SAlexei Starovoitov /* out: */ 492b52f00e6SAlexei Starovoitov *pprog = prog; 493b52f00e6SAlexei Starovoitov } 494b52f00e6SAlexei Starovoitov 495428d5df1SDaniel Borkmann static void emit_bpf_tail_call_direct(struct bpf_jit_poke_descriptor *poke, 496ebf7d1f5SMaciej Fijalkowski u8 **pprog, int addr, u8 *image, 497ebf7d1f5SMaciej Fijalkowski bool *callee_regs_used, u32 stack_depth) 498428d5df1SDaniel Borkmann { 499ebf7d1f5SMaciej Fijalkowski int tcc_off = -4 - round_up(stack_depth, 8); 500428d5df1SDaniel Borkmann u8 *prog = *pprog; 501ebf7d1f5SMaciej Fijalkowski int pop_bytes = 0; 5024d0b8c0bSMaciej Fijalkowski int off1 = 20; 503ebf7d1f5SMaciej Fijalkowski int poke_off; 504428d5df1SDaniel Borkmann int cnt = 0; 505428d5df1SDaniel Borkmann 506ebf7d1f5SMaciej Fijalkowski /* count the additional bytes used for popping callee regs to stack 507ebf7d1f5SMaciej Fijalkowski * that need to be taken into account for jump offset that is used for 508ebf7d1f5SMaciej Fijalkowski * bailing out from of the tail call when limit is reached 509ebf7d1f5SMaciej Fijalkowski */ 510ebf7d1f5SMaciej Fijalkowski pop_bytes = get_pop_bytes(callee_regs_used); 511ebf7d1f5SMaciej Fijalkowski off1 += pop_bytes; 512ebf7d1f5SMaciej Fijalkowski 513ebf7d1f5SMaciej Fijalkowski /* 514ebf7d1f5SMaciej Fijalkowski * total bytes for: 515ebf7d1f5SMaciej Fijalkowski * - nop5/ jmpq $off 516ebf7d1f5SMaciej Fijalkowski * - pop callee regs 5174d0b8c0bSMaciej Fijalkowski * - sub rsp, $val if depth > 0 518ebf7d1f5SMaciej Fijalkowski * - pop rax 519ebf7d1f5SMaciej Fijalkowski */ 5204d0b8c0bSMaciej Fijalkowski poke_off = X86_PATCH_SIZE + pop_bytes + 1; 5214d0b8c0bSMaciej Fijalkowski if (stack_depth) { 5224d0b8c0bSMaciej Fijalkowski poke_off += 7; 5234d0b8c0bSMaciej Fijalkowski off1 += 7; 5244d0b8c0bSMaciej Fijalkowski } 525ebf7d1f5SMaciej Fijalkowski 526428d5df1SDaniel Borkmann /* 527428d5df1SDaniel Borkmann * if (tail_call_cnt > MAX_TAIL_CALL_CNT) 528428d5df1SDaniel Borkmann * goto out; 529428d5df1SDaniel Borkmann */ 530ebf7d1f5SMaciej Fijalkowski EMIT2_off32(0x8B, 0x85, tcc_off); /* mov eax, dword ptr [rbp - tcc_off] */ 531428d5df1SDaniel Borkmann EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ 532ebf7d1f5SMaciej Fijalkowski EMIT2(X86_JA, off1); /* ja out */ 533428d5df1SDaniel Borkmann EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ 534ebf7d1f5SMaciej Fijalkowski EMIT2_off32(0x89, 0x85, tcc_off); /* mov dword ptr [rbp - tcc_off], eax */ 535428d5df1SDaniel Borkmann 536ebf7d1f5SMaciej Fijalkowski poke->tailcall_bypass = image + (addr - poke_off - X86_PATCH_SIZE); 537ebf7d1f5SMaciej Fijalkowski poke->adj_off = X86_TAIL_CALL_OFFSET; 538cf71b174SMaciej Fijalkowski poke->tailcall_target = image + (addr - X86_PATCH_SIZE); 539ebf7d1f5SMaciej Fijalkowski poke->bypass_addr = (u8 *)poke->tailcall_target + X86_PATCH_SIZE; 540ebf7d1f5SMaciej Fijalkowski 541ebf7d1f5SMaciej Fijalkowski emit_jump(&prog, (u8 *)poke->tailcall_target + X86_PATCH_SIZE, 542ebf7d1f5SMaciej Fijalkowski poke->tailcall_bypass); 543ebf7d1f5SMaciej Fijalkowski 544ebf7d1f5SMaciej Fijalkowski *pprog = prog; 545ebf7d1f5SMaciej Fijalkowski pop_callee_regs(pprog, callee_regs_used); 546ebf7d1f5SMaciej Fijalkowski prog = *pprog; 547ebf7d1f5SMaciej Fijalkowski EMIT1(0x58); /* pop rax */ 5484d0b8c0bSMaciej Fijalkowski if (stack_depth) 549ebf7d1f5SMaciej Fijalkowski EMIT3_off32(0x48, 0x81, 0xC4, round_up(stack_depth, 8)); 550428d5df1SDaniel Borkmann 551428d5df1SDaniel Borkmann memcpy(prog, ideal_nops[NOP_ATOMIC5], X86_PATCH_SIZE); 552428d5df1SDaniel Borkmann prog += X86_PATCH_SIZE; 553428d5df1SDaniel Borkmann /* out: */ 554428d5df1SDaniel Borkmann 555428d5df1SDaniel Borkmann *pprog = prog; 556428d5df1SDaniel Borkmann } 557428d5df1SDaniel Borkmann 558428d5df1SDaniel Borkmann static void bpf_tail_call_direct_fixup(struct bpf_prog *prog) 559428d5df1SDaniel Borkmann { 560428d5df1SDaniel Borkmann struct bpf_jit_poke_descriptor *poke; 561428d5df1SDaniel Borkmann struct bpf_array *array; 562428d5df1SDaniel Borkmann struct bpf_prog *target; 563428d5df1SDaniel Borkmann int i, ret; 564428d5df1SDaniel Borkmann 565428d5df1SDaniel Borkmann for (i = 0; i < prog->aux->size_poke_tab; i++) { 566428d5df1SDaniel Borkmann poke = &prog->aux->poke_tab[i]; 567cf71b174SMaciej Fijalkowski WARN_ON_ONCE(READ_ONCE(poke->tailcall_target_stable)); 568428d5df1SDaniel Borkmann 569428d5df1SDaniel Borkmann if (poke->reason != BPF_POKE_REASON_TAIL_CALL) 570428d5df1SDaniel Borkmann continue; 571428d5df1SDaniel Borkmann 572428d5df1SDaniel Borkmann array = container_of(poke->tail_call.map, struct bpf_array, map); 573428d5df1SDaniel Borkmann mutex_lock(&array->aux->poke_mutex); 574428d5df1SDaniel Borkmann target = array->ptrs[poke->tail_call.key]; 575428d5df1SDaniel Borkmann if (target) { 576428d5df1SDaniel Borkmann /* Plain memcpy is used when image is not live yet 577428d5df1SDaniel Borkmann * and still not locked as read-only. Once poke 578cf71b174SMaciej Fijalkowski * location is active (poke->tailcall_target_stable), 579cf71b174SMaciej Fijalkowski * any parallel bpf_arch_text_poke() might occur 580cf71b174SMaciej Fijalkowski * still on the read-write image until we finally 581cf71b174SMaciej Fijalkowski * locked it as read-only. Both modifications on 582cf71b174SMaciej Fijalkowski * the given image are under text_mutex to avoid 583cf71b174SMaciej Fijalkowski * interference. 584428d5df1SDaniel Borkmann */ 585cf71b174SMaciej Fijalkowski ret = __bpf_arch_text_poke(poke->tailcall_target, 586cf71b174SMaciej Fijalkowski BPF_MOD_JUMP, NULL, 587428d5df1SDaniel Borkmann (u8 *)target->bpf_func + 588428d5df1SDaniel Borkmann poke->adj_off, false); 589428d5df1SDaniel Borkmann BUG_ON(ret < 0); 590ebf7d1f5SMaciej Fijalkowski ret = __bpf_arch_text_poke(poke->tailcall_bypass, 591ebf7d1f5SMaciej Fijalkowski BPF_MOD_JUMP, 592ebf7d1f5SMaciej Fijalkowski (u8 *)poke->tailcall_target + 593ebf7d1f5SMaciej Fijalkowski X86_PATCH_SIZE, NULL, false); 594ebf7d1f5SMaciej Fijalkowski BUG_ON(ret < 0); 595428d5df1SDaniel Borkmann } 596cf71b174SMaciej Fijalkowski WRITE_ONCE(poke->tailcall_target_stable, true); 597428d5df1SDaniel Borkmann mutex_unlock(&array->aux->poke_mutex); 598428d5df1SDaniel Borkmann } 599428d5df1SDaniel Borkmann } 600428d5df1SDaniel Borkmann 6016fe8b9c1SDaniel Borkmann static void emit_mov_imm32(u8 **pprog, bool sign_propagate, 6026fe8b9c1SDaniel Borkmann u32 dst_reg, const u32 imm32) 6036fe8b9c1SDaniel Borkmann { 6046fe8b9c1SDaniel Borkmann u8 *prog = *pprog; 6056fe8b9c1SDaniel Borkmann u8 b1, b2, b3; 6066fe8b9c1SDaniel Borkmann int cnt = 0; 6076fe8b9c1SDaniel Borkmann 608a2c7a983SIngo Molnar /* 609a2c7a983SIngo Molnar * Optimization: if imm32 is positive, use 'mov %eax, imm32' 6106fe8b9c1SDaniel Borkmann * (which zero-extends imm32) to save 2 bytes. 6116fe8b9c1SDaniel Borkmann */ 6126fe8b9c1SDaniel Borkmann if (sign_propagate && (s32)imm32 < 0) { 6136fe8b9c1SDaniel Borkmann /* 'mov %rax, imm32' sign extends imm32 */ 6146fe8b9c1SDaniel Borkmann b1 = add_1mod(0x48, dst_reg); 6156fe8b9c1SDaniel Borkmann b2 = 0xC7; 6166fe8b9c1SDaniel Borkmann b3 = 0xC0; 6176fe8b9c1SDaniel Borkmann EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); 6186fe8b9c1SDaniel Borkmann goto done; 6196fe8b9c1SDaniel Borkmann } 6206fe8b9c1SDaniel Borkmann 621a2c7a983SIngo Molnar /* 622a2c7a983SIngo Molnar * Optimization: if imm32 is zero, use 'xor %eax, %eax' 6236fe8b9c1SDaniel Borkmann * to save 3 bytes. 6246fe8b9c1SDaniel Borkmann */ 6256fe8b9c1SDaniel Borkmann if (imm32 == 0) { 6266fe8b9c1SDaniel Borkmann if (is_ereg(dst_reg)) 6276fe8b9c1SDaniel Borkmann EMIT1(add_2mod(0x40, dst_reg, dst_reg)); 6286fe8b9c1SDaniel Borkmann b2 = 0x31; /* xor */ 6296fe8b9c1SDaniel Borkmann b3 = 0xC0; 6306fe8b9c1SDaniel Borkmann EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); 6316fe8b9c1SDaniel Borkmann goto done; 6326fe8b9c1SDaniel Borkmann } 6336fe8b9c1SDaniel Borkmann 6346fe8b9c1SDaniel Borkmann /* mov %eax, imm32 */ 6356fe8b9c1SDaniel Borkmann if (is_ereg(dst_reg)) 6366fe8b9c1SDaniel Borkmann EMIT1(add_1mod(0x40, dst_reg)); 6376fe8b9c1SDaniel Borkmann EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); 6386fe8b9c1SDaniel Borkmann done: 6396fe8b9c1SDaniel Borkmann *pprog = prog; 6406fe8b9c1SDaniel Borkmann } 6416fe8b9c1SDaniel Borkmann 6426fe8b9c1SDaniel Borkmann static void emit_mov_imm64(u8 **pprog, u32 dst_reg, 6436fe8b9c1SDaniel Borkmann const u32 imm32_hi, const u32 imm32_lo) 6446fe8b9c1SDaniel Borkmann { 6456fe8b9c1SDaniel Borkmann u8 *prog = *pprog; 6466fe8b9c1SDaniel Borkmann int cnt = 0; 6476fe8b9c1SDaniel Borkmann 6486fe8b9c1SDaniel Borkmann if (is_uimm32(((u64)imm32_hi << 32) | (u32)imm32_lo)) { 649a2c7a983SIngo Molnar /* 650a2c7a983SIngo Molnar * For emitting plain u32, where sign bit must not be 6516fe8b9c1SDaniel Borkmann * propagated LLVM tends to load imm64 over mov32 6526fe8b9c1SDaniel Borkmann * directly, so save couple of bytes by just doing 6536fe8b9c1SDaniel Borkmann * 'mov %eax, imm32' instead. 6546fe8b9c1SDaniel Borkmann */ 6556fe8b9c1SDaniel Borkmann emit_mov_imm32(&prog, false, dst_reg, imm32_lo); 6566fe8b9c1SDaniel Borkmann } else { 6576fe8b9c1SDaniel Borkmann /* movabsq %rax, imm64 */ 6586fe8b9c1SDaniel Borkmann EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); 6596fe8b9c1SDaniel Borkmann EMIT(imm32_lo, 4); 6606fe8b9c1SDaniel Borkmann EMIT(imm32_hi, 4); 6616fe8b9c1SDaniel Borkmann } 6626fe8b9c1SDaniel Borkmann 6636fe8b9c1SDaniel Borkmann *pprog = prog; 6646fe8b9c1SDaniel Borkmann } 6656fe8b9c1SDaniel Borkmann 6664c38e2f3SDaniel Borkmann static void emit_mov_reg(u8 **pprog, bool is64, u32 dst_reg, u32 src_reg) 6674c38e2f3SDaniel Borkmann { 6684c38e2f3SDaniel Borkmann u8 *prog = *pprog; 6694c38e2f3SDaniel Borkmann int cnt = 0; 6704c38e2f3SDaniel Borkmann 6714c38e2f3SDaniel Borkmann if (is64) { 6724c38e2f3SDaniel Borkmann /* mov dst, src */ 6734c38e2f3SDaniel Borkmann EMIT_mov(dst_reg, src_reg); 6744c38e2f3SDaniel Borkmann } else { 6754c38e2f3SDaniel Borkmann /* mov32 dst, src */ 6764c38e2f3SDaniel Borkmann if (is_ereg(dst_reg) || is_ereg(src_reg)) 6774c38e2f3SDaniel Borkmann EMIT1(add_2mod(0x40, dst_reg, src_reg)); 6784c38e2f3SDaniel Borkmann EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); 6794c38e2f3SDaniel Borkmann } 6804c38e2f3SDaniel Borkmann 6814c38e2f3SDaniel Borkmann *pprog = prog; 6824c38e2f3SDaniel Borkmann } 6834c38e2f3SDaniel Borkmann 68411c11d07SBrendan Jackman /* Emit the suffix (ModR/M etc) for addressing *(ptr_reg + off) and val_reg */ 68511c11d07SBrendan Jackman static void emit_insn_suffix(u8 **pprog, u32 ptr_reg, u32 val_reg, int off) 68611c11d07SBrendan Jackman { 68711c11d07SBrendan Jackman u8 *prog = *pprog; 68811c11d07SBrendan Jackman int cnt = 0; 68911c11d07SBrendan Jackman 69011c11d07SBrendan Jackman if (is_imm8(off)) { 69111c11d07SBrendan Jackman /* 1-byte signed displacement. 69211c11d07SBrendan Jackman * 69311c11d07SBrendan Jackman * If off == 0 we could skip this and save one extra byte, but 69411c11d07SBrendan Jackman * special case of x86 R13 which always needs an offset is not 69511c11d07SBrendan Jackman * worth the hassle 69611c11d07SBrendan Jackman */ 69711c11d07SBrendan Jackman EMIT2(add_2reg(0x40, ptr_reg, val_reg), off); 69811c11d07SBrendan Jackman } else { 69911c11d07SBrendan Jackman /* 4-byte signed displacement */ 70011c11d07SBrendan Jackman EMIT1_off32(add_2reg(0x80, ptr_reg, val_reg), off); 70111c11d07SBrendan Jackman } 70211c11d07SBrendan Jackman *pprog = prog; 70311c11d07SBrendan Jackman } 70411c11d07SBrendan Jackman 705*74007cfcSBrendan Jackman /* 706*74007cfcSBrendan Jackman * Emit a REX byte if it will be necessary to address these registers 707*74007cfcSBrendan Jackman */ 708*74007cfcSBrendan Jackman static void maybe_emit_mod(u8 **pprog, u32 dst_reg, u32 src_reg, bool is64) 709*74007cfcSBrendan Jackman { 710*74007cfcSBrendan Jackman u8 *prog = *pprog; 711*74007cfcSBrendan Jackman int cnt = 0; 712*74007cfcSBrendan Jackman 713*74007cfcSBrendan Jackman if (is64) 714*74007cfcSBrendan Jackman EMIT1(add_2mod(0x48, dst_reg, src_reg)); 715*74007cfcSBrendan Jackman else if (is_ereg(dst_reg) || is_ereg(src_reg)) 716*74007cfcSBrendan Jackman EMIT1(add_2mod(0x40, dst_reg, src_reg)); 717*74007cfcSBrendan Jackman *pprog = prog; 718*74007cfcSBrendan Jackman } 719*74007cfcSBrendan Jackman 7203b2744e6SAlexei Starovoitov /* LDX: dst_reg = *(u8*)(src_reg + off) */ 7213b2744e6SAlexei Starovoitov static void emit_ldx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) 7223b2744e6SAlexei Starovoitov { 7233b2744e6SAlexei Starovoitov u8 *prog = *pprog; 7243b2744e6SAlexei Starovoitov int cnt = 0; 7253b2744e6SAlexei Starovoitov 7263b2744e6SAlexei Starovoitov switch (size) { 7273b2744e6SAlexei Starovoitov case BPF_B: 7283b2744e6SAlexei Starovoitov /* Emit 'movzx rax, byte ptr [rax + off]' */ 7293b2744e6SAlexei Starovoitov EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); 7303b2744e6SAlexei Starovoitov break; 7313b2744e6SAlexei Starovoitov case BPF_H: 7323b2744e6SAlexei Starovoitov /* Emit 'movzx rax, word ptr [rax + off]' */ 7333b2744e6SAlexei Starovoitov EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); 7343b2744e6SAlexei Starovoitov break; 7353b2744e6SAlexei Starovoitov case BPF_W: 7363b2744e6SAlexei Starovoitov /* Emit 'mov eax, dword ptr [rax+0x14]' */ 7373b2744e6SAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 7383b2744e6SAlexei Starovoitov EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); 7393b2744e6SAlexei Starovoitov else 7403b2744e6SAlexei Starovoitov EMIT1(0x8B); 7413b2744e6SAlexei Starovoitov break; 7423b2744e6SAlexei Starovoitov case BPF_DW: 7433b2744e6SAlexei Starovoitov /* Emit 'mov rax, qword ptr [rax+0x14]' */ 7443b2744e6SAlexei Starovoitov EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); 7453b2744e6SAlexei Starovoitov break; 7463b2744e6SAlexei Starovoitov } 74711c11d07SBrendan Jackman emit_insn_suffix(&prog, src_reg, dst_reg, off); 7483b2744e6SAlexei Starovoitov *pprog = prog; 7493b2744e6SAlexei Starovoitov } 7503b2744e6SAlexei Starovoitov 7513b2744e6SAlexei Starovoitov /* STX: *(u8*)(dst_reg + off) = src_reg */ 7523b2744e6SAlexei Starovoitov static void emit_stx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) 7533b2744e6SAlexei Starovoitov { 7543b2744e6SAlexei Starovoitov u8 *prog = *pprog; 7553b2744e6SAlexei Starovoitov int cnt = 0; 7563b2744e6SAlexei Starovoitov 7573b2744e6SAlexei Starovoitov switch (size) { 7583b2744e6SAlexei Starovoitov case BPF_B: 7593b2744e6SAlexei Starovoitov /* Emit 'mov byte ptr [rax + off], al' */ 760aee194b1SLuke Nelson if (is_ereg(dst_reg) || is_ereg_8l(src_reg)) 761aee194b1SLuke Nelson /* Add extra byte for eregs or SIL,DIL,BPL in src_reg */ 7623b2744e6SAlexei Starovoitov EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); 7633b2744e6SAlexei Starovoitov else 7643b2744e6SAlexei Starovoitov EMIT1(0x88); 7653b2744e6SAlexei Starovoitov break; 7663b2744e6SAlexei Starovoitov case BPF_H: 7673b2744e6SAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 7683b2744e6SAlexei Starovoitov EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); 7693b2744e6SAlexei Starovoitov else 7703b2744e6SAlexei Starovoitov EMIT2(0x66, 0x89); 7713b2744e6SAlexei Starovoitov break; 7723b2744e6SAlexei Starovoitov case BPF_W: 7733b2744e6SAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 7743b2744e6SAlexei Starovoitov EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); 7753b2744e6SAlexei Starovoitov else 7763b2744e6SAlexei Starovoitov EMIT1(0x89); 7773b2744e6SAlexei Starovoitov break; 7783b2744e6SAlexei Starovoitov case BPF_DW: 7793b2744e6SAlexei Starovoitov EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); 7803b2744e6SAlexei Starovoitov break; 7813b2744e6SAlexei Starovoitov } 78211c11d07SBrendan Jackman emit_insn_suffix(&prog, dst_reg, src_reg, off); 7833b2744e6SAlexei Starovoitov *pprog = prog; 7843b2744e6SAlexei Starovoitov } 7853b2744e6SAlexei Starovoitov 7863dec541bSAlexei Starovoitov static bool ex_handler_bpf(const struct exception_table_entry *x, 7873dec541bSAlexei Starovoitov struct pt_regs *regs, int trapnr, 7883dec541bSAlexei Starovoitov unsigned long error_code, unsigned long fault_addr) 7893dec541bSAlexei Starovoitov { 7903dec541bSAlexei Starovoitov u32 reg = x->fixup >> 8; 7913dec541bSAlexei Starovoitov 7923dec541bSAlexei Starovoitov /* jump over faulting load and clear dest register */ 7933dec541bSAlexei Starovoitov *(unsigned long *)((void *)regs + reg) = 0; 7943dec541bSAlexei Starovoitov regs->ip += x->fixup & 0xff; 7953dec541bSAlexei Starovoitov return true; 7963dec541bSAlexei Starovoitov } 7973dec541bSAlexei Starovoitov 798ebf7d1f5SMaciej Fijalkowski static void detect_reg_usage(struct bpf_insn *insn, int insn_cnt, 799ebf7d1f5SMaciej Fijalkowski bool *regs_used, bool *tail_call_seen) 800ebf7d1f5SMaciej Fijalkowski { 801ebf7d1f5SMaciej Fijalkowski int i; 802ebf7d1f5SMaciej Fijalkowski 803ebf7d1f5SMaciej Fijalkowski for (i = 1; i <= insn_cnt; i++, insn++) { 804ebf7d1f5SMaciej Fijalkowski if (insn->code == (BPF_JMP | BPF_TAIL_CALL)) 805ebf7d1f5SMaciej Fijalkowski *tail_call_seen = true; 806ebf7d1f5SMaciej Fijalkowski if (insn->dst_reg == BPF_REG_6 || insn->src_reg == BPF_REG_6) 807ebf7d1f5SMaciej Fijalkowski regs_used[0] = true; 808ebf7d1f5SMaciej Fijalkowski if (insn->dst_reg == BPF_REG_7 || insn->src_reg == BPF_REG_7) 809ebf7d1f5SMaciej Fijalkowski regs_used[1] = true; 810ebf7d1f5SMaciej Fijalkowski if (insn->dst_reg == BPF_REG_8 || insn->src_reg == BPF_REG_8) 811ebf7d1f5SMaciej Fijalkowski regs_used[2] = true; 812ebf7d1f5SMaciej Fijalkowski if (insn->dst_reg == BPF_REG_9 || insn->src_reg == BPF_REG_9) 813ebf7d1f5SMaciej Fijalkowski regs_used[3] = true; 814ebf7d1f5SMaciej Fijalkowski } 815ebf7d1f5SMaciej Fijalkowski } 816ebf7d1f5SMaciej Fijalkowski 817b52f00e6SAlexei Starovoitov static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, 818b52f00e6SAlexei Starovoitov int oldproglen, struct jit_context *ctx) 819b52f00e6SAlexei Starovoitov { 820ebf7d1f5SMaciej Fijalkowski bool tail_call_reachable = bpf_prog->aux->tail_call_reachable; 821b52f00e6SAlexei Starovoitov struct bpf_insn *insn = bpf_prog->insnsi; 822ebf7d1f5SMaciej Fijalkowski bool callee_regs_used[4] = {}; 823b52f00e6SAlexei Starovoitov int insn_cnt = bpf_prog->len; 824ebf7d1f5SMaciej Fijalkowski bool tail_call_seen = false; 825b52f00e6SAlexei Starovoitov bool seen_exit = false; 826b52f00e6SAlexei Starovoitov u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; 8273dec541bSAlexei Starovoitov int i, cnt = 0, excnt = 0; 828b52f00e6SAlexei Starovoitov int proglen = 0; 829b52f00e6SAlexei Starovoitov u8 *prog = temp; 830b52f00e6SAlexei Starovoitov 831ebf7d1f5SMaciej Fijalkowski detect_reg_usage(insn, insn_cnt, callee_regs_used, 832ebf7d1f5SMaciej Fijalkowski &tail_call_seen); 833ebf7d1f5SMaciej Fijalkowski 834ebf7d1f5SMaciej Fijalkowski /* tail call's presence in current prog implies it is reachable */ 835ebf7d1f5SMaciej Fijalkowski tail_call_reachable |= tail_call_seen; 836ebf7d1f5SMaciej Fijalkowski 83708691752SDaniel Borkmann emit_prologue(&prog, bpf_prog->aux->stack_depth, 838ebf7d1f5SMaciej Fijalkowski bpf_prog_was_classic(bpf_prog), tail_call_reachable, 839ebf7d1f5SMaciej Fijalkowski bpf_prog->aux->func_idx != 0); 840ebf7d1f5SMaciej Fijalkowski push_callee_regs(&prog, callee_regs_used); 8417c2e988fSAlexei Starovoitov addrs[0] = prog - temp; 842b52f00e6SAlexei Starovoitov 8437c2e988fSAlexei Starovoitov for (i = 1; i <= insn_cnt; i++, insn++) { 844e430f34eSAlexei Starovoitov const s32 imm32 = insn->imm; 845e430f34eSAlexei Starovoitov u32 dst_reg = insn->dst_reg; 846e430f34eSAlexei Starovoitov u32 src_reg = insn->src_reg; 8476fe8b9c1SDaniel Borkmann u8 b2 = 0, b3 = 0; 84862258278SAlexei Starovoitov s64 jmp_offset; 84962258278SAlexei Starovoitov u8 jmp_cond; 85062258278SAlexei Starovoitov int ilen; 85162258278SAlexei Starovoitov u8 *func; 85262258278SAlexei Starovoitov 85362258278SAlexei Starovoitov switch (insn->code) { 85462258278SAlexei Starovoitov /* ALU */ 85562258278SAlexei Starovoitov case BPF_ALU | BPF_ADD | BPF_X: 85662258278SAlexei Starovoitov case BPF_ALU | BPF_SUB | BPF_X: 85762258278SAlexei Starovoitov case BPF_ALU | BPF_AND | BPF_X: 85862258278SAlexei Starovoitov case BPF_ALU | BPF_OR | BPF_X: 85962258278SAlexei Starovoitov case BPF_ALU | BPF_XOR | BPF_X: 86062258278SAlexei Starovoitov case BPF_ALU64 | BPF_ADD | BPF_X: 86162258278SAlexei Starovoitov case BPF_ALU64 | BPF_SUB | BPF_X: 86262258278SAlexei Starovoitov case BPF_ALU64 | BPF_AND | BPF_X: 86362258278SAlexei Starovoitov case BPF_ALU64 | BPF_OR | BPF_X: 86462258278SAlexei Starovoitov case BPF_ALU64 | BPF_XOR | BPF_X: 86562258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 86662258278SAlexei Starovoitov case BPF_ADD: b2 = 0x01; break; 86762258278SAlexei Starovoitov case BPF_SUB: b2 = 0x29; break; 86862258278SAlexei Starovoitov case BPF_AND: b2 = 0x21; break; 86962258278SAlexei Starovoitov case BPF_OR: b2 = 0x09; break; 87062258278SAlexei Starovoitov case BPF_XOR: b2 = 0x31; break; 87162258278SAlexei Starovoitov } 872*74007cfcSBrendan Jackman maybe_emit_mod(&prog, dst_reg, src_reg, 873*74007cfcSBrendan Jackman BPF_CLASS(insn->code) == BPF_ALU64); 874e430f34eSAlexei Starovoitov EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); 8750a14842fSEric Dumazet break; 87662258278SAlexei Starovoitov 87762258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOV | BPF_X: 87862258278SAlexei Starovoitov case BPF_ALU | BPF_MOV | BPF_X: 8794c38e2f3SDaniel Borkmann emit_mov_reg(&prog, 8804c38e2f3SDaniel Borkmann BPF_CLASS(insn->code) == BPF_ALU64, 8814c38e2f3SDaniel Borkmann dst_reg, src_reg); 88262258278SAlexei Starovoitov break; 88362258278SAlexei Starovoitov 884e430f34eSAlexei Starovoitov /* neg dst */ 88562258278SAlexei Starovoitov case BPF_ALU | BPF_NEG: 88662258278SAlexei Starovoitov case BPF_ALU64 | BPF_NEG: 88762258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 888e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 889e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg)) 890e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 891e430f34eSAlexei Starovoitov EMIT2(0xF7, add_1reg(0xD8, dst_reg)); 89262258278SAlexei Starovoitov break; 89362258278SAlexei Starovoitov 89462258278SAlexei Starovoitov case BPF_ALU | BPF_ADD | BPF_K: 89562258278SAlexei Starovoitov case BPF_ALU | BPF_SUB | BPF_K: 89662258278SAlexei Starovoitov case BPF_ALU | BPF_AND | BPF_K: 89762258278SAlexei Starovoitov case BPF_ALU | BPF_OR | BPF_K: 89862258278SAlexei Starovoitov case BPF_ALU | BPF_XOR | BPF_K: 89962258278SAlexei Starovoitov case BPF_ALU64 | BPF_ADD | BPF_K: 90062258278SAlexei Starovoitov case BPF_ALU64 | BPF_SUB | BPF_K: 90162258278SAlexei Starovoitov case BPF_ALU64 | BPF_AND | BPF_K: 90262258278SAlexei Starovoitov case BPF_ALU64 | BPF_OR | BPF_K: 90362258278SAlexei Starovoitov case BPF_ALU64 | BPF_XOR | BPF_K: 90462258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 905e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 906e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg)) 907e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 90862258278SAlexei Starovoitov 909a2c7a983SIngo Molnar /* 910a2c7a983SIngo Molnar * b3 holds 'normal' opcode, b2 short form only valid 911de0a444dSDaniel Borkmann * in case dst is eax/rax. 912de0a444dSDaniel Borkmann */ 91362258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 914de0a444dSDaniel Borkmann case BPF_ADD: 915de0a444dSDaniel Borkmann b3 = 0xC0; 916de0a444dSDaniel Borkmann b2 = 0x05; 917de0a444dSDaniel Borkmann break; 918de0a444dSDaniel Borkmann case BPF_SUB: 919de0a444dSDaniel Borkmann b3 = 0xE8; 920de0a444dSDaniel Borkmann b2 = 0x2D; 921de0a444dSDaniel Borkmann break; 922de0a444dSDaniel Borkmann case BPF_AND: 923de0a444dSDaniel Borkmann b3 = 0xE0; 924de0a444dSDaniel Borkmann b2 = 0x25; 925de0a444dSDaniel Borkmann break; 926de0a444dSDaniel Borkmann case BPF_OR: 927de0a444dSDaniel Borkmann b3 = 0xC8; 928de0a444dSDaniel Borkmann b2 = 0x0D; 929de0a444dSDaniel Borkmann break; 930de0a444dSDaniel Borkmann case BPF_XOR: 931de0a444dSDaniel Borkmann b3 = 0xF0; 932de0a444dSDaniel Borkmann b2 = 0x35; 933de0a444dSDaniel Borkmann break; 93462258278SAlexei Starovoitov } 93562258278SAlexei Starovoitov 936e430f34eSAlexei Starovoitov if (is_imm8(imm32)) 937e430f34eSAlexei Starovoitov EMIT3(0x83, add_1reg(b3, dst_reg), imm32); 938de0a444dSDaniel Borkmann else if (is_axreg(dst_reg)) 939de0a444dSDaniel Borkmann EMIT1_off32(b2, imm32); 94062258278SAlexei Starovoitov else 941e430f34eSAlexei Starovoitov EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); 94262258278SAlexei Starovoitov break; 94362258278SAlexei Starovoitov 94462258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOV | BPF_K: 94562258278SAlexei Starovoitov case BPF_ALU | BPF_MOV | BPF_K: 9466fe8b9c1SDaniel Borkmann emit_mov_imm32(&prog, BPF_CLASS(insn->code) == BPF_ALU64, 9476fe8b9c1SDaniel Borkmann dst_reg, imm32); 94862258278SAlexei Starovoitov break; 94962258278SAlexei Starovoitov 95002ab695bSAlexei Starovoitov case BPF_LD | BPF_IMM | BPF_DW: 9516fe8b9c1SDaniel Borkmann emit_mov_imm64(&prog, dst_reg, insn[1].imm, insn[0].imm); 95202ab695bSAlexei Starovoitov insn++; 95302ab695bSAlexei Starovoitov i++; 95402ab695bSAlexei Starovoitov break; 95502ab695bSAlexei Starovoitov 956e430f34eSAlexei Starovoitov /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ 95762258278SAlexei Starovoitov case BPF_ALU | BPF_MOD | BPF_X: 95862258278SAlexei Starovoitov case BPF_ALU | BPF_DIV | BPF_X: 95962258278SAlexei Starovoitov case BPF_ALU | BPF_MOD | BPF_K: 96062258278SAlexei Starovoitov case BPF_ALU | BPF_DIV | BPF_K: 96162258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOD | BPF_X: 96262258278SAlexei Starovoitov case BPF_ALU64 | BPF_DIV | BPF_X: 96362258278SAlexei Starovoitov case BPF_ALU64 | BPF_MOD | BPF_K: 96462258278SAlexei Starovoitov case BPF_ALU64 | BPF_DIV | BPF_K: 96562258278SAlexei Starovoitov EMIT1(0x50); /* push rax */ 96662258278SAlexei Starovoitov EMIT1(0x52); /* push rdx */ 96762258278SAlexei Starovoitov 96862258278SAlexei Starovoitov if (BPF_SRC(insn->code) == BPF_X) 969e430f34eSAlexei Starovoitov /* mov r11, src_reg */ 970e430f34eSAlexei Starovoitov EMIT_mov(AUX_REG, src_reg); 97162258278SAlexei Starovoitov else 972e430f34eSAlexei Starovoitov /* mov r11, imm32 */ 973e430f34eSAlexei Starovoitov EMIT3_off32(0x49, 0xC7, 0xC3, imm32); 97462258278SAlexei Starovoitov 975e430f34eSAlexei Starovoitov /* mov rax, dst_reg */ 976e430f34eSAlexei Starovoitov EMIT_mov(BPF_REG_0, dst_reg); 97762258278SAlexei Starovoitov 978a2c7a983SIngo Molnar /* 979a2c7a983SIngo Molnar * xor edx, edx 98062258278SAlexei Starovoitov * equivalent to 'xor rdx, rdx', but one byte less 98162258278SAlexei Starovoitov */ 98262258278SAlexei Starovoitov EMIT2(0x31, 0xd2); 98362258278SAlexei Starovoitov 98462258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 98562258278SAlexei Starovoitov /* div r11 */ 98662258278SAlexei Starovoitov EMIT3(0x49, 0xF7, 0xF3); 98762258278SAlexei Starovoitov else 98862258278SAlexei Starovoitov /* div r11d */ 98962258278SAlexei Starovoitov EMIT3(0x41, 0xF7, 0xF3); 99062258278SAlexei Starovoitov 99162258278SAlexei Starovoitov if (BPF_OP(insn->code) == BPF_MOD) 99262258278SAlexei Starovoitov /* mov r11, rdx */ 99362258278SAlexei Starovoitov EMIT3(0x49, 0x89, 0xD3); 99462258278SAlexei Starovoitov else 99562258278SAlexei Starovoitov /* mov r11, rax */ 99662258278SAlexei Starovoitov EMIT3(0x49, 0x89, 0xC3); 99762258278SAlexei Starovoitov 99862258278SAlexei Starovoitov EMIT1(0x5A); /* pop rdx */ 99962258278SAlexei Starovoitov EMIT1(0x58); /* pop rax */ 100062258278SAlexei Starovoitov 1001e430f34eSAlexei Starovoitov /* mov dst_reg, r11 */ 1002e430f34eSAlexei Starovoitov EMIT_mov(dst_reg, AUX_REG); 100362258278SAlexei Starovoitov break; 100462258278SAlexei Starovoitov 100562258278SAlexei Starovoitov case BPF_ALU | BPF_MUL | BPF_K: 100662258278SAlexei Starovoitov case BPF_ALU | BPF_MUL | BPF_X: 100762258278SAlexei Starovoitov case BPF_ALU64 | BPF_MUL | BPF_K: 100862258278SAlexei Starovoitov case BPF_ALU64 | BPF_MUL | BPF_X: 10094c38e2f3SDaniel Borkmann { 10104c38e2f3SDaniel Borkmann bool is64 = BPF_CLASS(insn->code) == BPF_ALU64; 10114c38e2f3SDaniel Borkmann 1012d806a0cfSDaniel Borkmann if (dst_reg != BPF_REG_0) 101362258278SAlexei Starovoitov EMIT1(0x50); /* push rax */ 1014d806a0cfSDaniel Borkmann if (dst_reg != BPF_REG_3) 101562258278SAlexei Starovoitov EMIT1(0x52); /* push rdx */ 101662258278SAlexei Starovoitov 1017e430f34eSAlexei Starovoitov /* mov r11, dst_reg */ 1018e430f34eSAlexei Starovoitov EMIT_mov(AUX_REG, dst_reg); 101962258278SAlexei Starovoitov 102062258278SAlexei Starovoitov if (BPF_SRC(insn->code) == BPF_X) 10214c38e2f3SDaniel Borkmann emit_mov_reg(&prog, is64, BPF_REG_0, src_reg); 102262258278SAlexei Starovoitov else 10234c38e2f3SDaniel Borkmann emit_mov_imm32(&prog, is64, BPF_REG_0, imm32); 102462258278SAlexei Starovoitov 10254c38e2f3SDaniel Borkmann if (is64) 102662258278SAlexei Starovoitov EMIT1(add_1mod(0x48, AUX_REG)); 102762258278SAlexei Starovoitov else if (is_ereg(AUX_REG)) 102862258278SAlexei Starovoitov EMIT1(add_1mod(0x40, AUX_REG)); 102962258278SAlexei Starovoitov /* mul(q) r11 */ 103062258278SAlexei Starovoitov EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); 103162258278SAlexei Starovoitov 1032d806a0cfSDaniel Borkmann if (dst_reg != BPF_REG_3) 103362258278SAlexei Starovoitov EMIT1(0x5A); /* pop rdx */ 1034d806a0cfSDaniel Borkmann if (dst_reg != BPF_REG_0) { 1035d806a0cfSDaniel Borkmann /* mov dst_reg, rax */ 1036d806a0cfSDaniel Borkmann EMIT_mov(dst_reg, BPF_REG_0); 103762258278SAlexei Starovoitov EMIT1(0x58); /* pop rax */ 1038d806a0cfSDaniel Borkmann } 103962258278SAlexei Starovoitov break; 10404c38e2f3SDaniel Borkmann } 1041a2c7a983SIngo Molnar /* Shifts */ 104262258278SAlexei Starovoitov case BPF_ALU | BPF_LSH | BPF_K: 104362258278SAlexei Starovoitov case BPF_ALU | BPF_RSH | BPF_K: 104462258278SAlexei Starovoitov case BPF_ALU | BPF_ARSH | BPF_K: 104562258278SAlexei Starovoitov case BPF_ALU64 | BPF_LSH | BPF_K: 104662258278SAlexei Starovoitov case BPF_ALU64 | BPF_RSH | BPF_K: 104762258278SAlexei Starovoitov case BPF_ALU64 | BPF_ARSH | BPF_K: 104862258278SAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 1049e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 1050e430f34eSAlexei Starovoitov else if (is_ereg(dst_reg)) 1051e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 105262258278SAlexei Starovoitov 105362258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 105462258278SAlexei Starovoitov case BPF_LSH: b3 = 0xE0; break; 105562258278SAlexei Starovoitov case BPF_RSH: b3 = 0xE8; break; 105662258278SAlexei Starovoitov case BPF_ARSH: b3 = 0xF8; break; 105762258278SAlexei Starovoitov } 105888e69a1fSDaniel Borkmann 105988e69a1fSDaniel Borkmann if (imm32 == 1) 106088e69a1fSDaniel Borkmann EMIT2(0xD1, add_1reg(b3, dst_reg)); 106188e69a1fSDaniel Borkmann else 1062e430f34eSAlexei Starovoitov EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); 106362258278SAlexei Starovoitov break; 106462258278SAlexei Starovoitov 106572b603eeSAlexei Starovoitov case BPF_ALU | BPF_LSH | BPF_X: 106672b603eeSAlexei Starovoitov case BPF_ALU | BPF_RSH | BPF_X: 106772b603eeSAlexei Starovoitov case BPF_ALU | BPF_ARSH | BPF_X: 106872b603eeSAlexei Starovoitov case BPF_ALU64 | BPF_LSH | BPF_X: 106972b603eeSAlexei Starovoitov case BPF_ALU64 | BPF_RSH | BPF_X: 107072b603eeSAlexei Starovoitov case BPF_ALU64 | BPF_ARSH | BPF_X: 107172b603eeSAlexei Starovoitov 1072a2c7a983SIngo Molnar /* Check for bad case when dst_reg == rcx */ 107372b603eeSAlexei Starovoitov if (dst_reg == BPF_REG_4) { 107472b603eeSAlexei Starovoitov /* mov r11, dst_reg */ 107572b603eeSAlexei Starovoitov EMIT_mov(AUX_REG, dst_reg); 107672b603eeSAlexei Starovoitov dst_reg = AUX_REG; 107772b603eeSAlexei Starovoitov } 107872b603eeSAlexei Starovoitov 107972b603eeSAlexei Starovoitov if (src_reg != BPF_REG_4) { /* common case */ 108072b603eeSAlexei Starovoitov EMIT1(0x51); /* push rcx */ 108172b603eeSAlexei Starovoitov 108272b603eeSAlexei Starovoitov /* mov rcx, src_reg */ 108372b603eeSAlexei Starovoitov EMIT_mov(BPF_REG_4, src_reg); 108472b603eeSAlexei Starovoitov } 108572b603eeSAlexei Starovoitov 108672b603eeSAlexei Starovoitov /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ 108772b603eeSAlexei Starovoitov if (BPF_CLASS(insn->code) == BPF_ALU64) 108872b603eeSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 108972b603eeSAlexei Starovoitov else if (is_ereg(dst_reg)) 109072b603eeSAlexei Starovoitov EMIT1(add_1mod(0x40, dst_reg)); 109172b603eeSAlexei Starovoitov 109272b603eeSAlexei Starovoitov switch (BPF_OP(insn->code)) { 109372b603eeSAlexei Starovoitov case BPF_LSH: b3 = 0xE0; break; 109472b603eeSAlexei Starovoitov case BPF_RSH: b3 = 0xE8; break; 109572b603eeSAlexei Starovoitov case BPF_ARSH: b3 = 0xF8; break; 109672b603eeSAlexei Starovoitov } 109772b603eeSAlexei Starovoitov EMIT2(0xD3, add_1reg(b3, dst_reg)); 109872b603eeSAlexei Starovoitov 109972b603eeSAlexei Starovoitov if (src_reg != BPF_REG_4) 110072b603eeSAlexei Starovoitov EMIT1(0x59); /* pop rcx */ 110172b603eeSAlexei Starovoitov 110272b603eeSAlexei Starovoitov if (insn->dst_reg == BPF_REG_4) 110372b603eeSAlexei Starovoitov /* mov dst_reg, r11 */ 110472b603eeSAlexei Starovoitov EMIT_mov(insn->dst_reg, AUX_REG); 110572b603eeSAlexei Starovoitov break; 110672b603eeSAlexei Starovoitov 110762258278SAlexei Starovoitov case BPF_ALU | BPF_END | BPF_FROM_BE: 1108e430f34eSAlexei Starovoitov switch (imm32) { 110962258278SAlexei Starovoitov case 16: 1110a2c7a983SIngo Molnar /* Emit 'ror %ax, 8' to swap lower 2 bytes */ 111162258278SAlexei Starovoitov EMIT1(0x66); 1112e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 111362258278SAlexei Starovoitov EMIT1(0x41); 1114e430f34eSAlexei Starovoitov EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); 1115343f845bSAlexei Starovoitov 1116a2c7a983SIngo Molnar /* Emit 'movzwl eax, ax' */ 1117343f845bSAlexei Starovoitov if (is_ereg(dst_reg)) 1118343f845bSAlexei Starovoitov EMIT3(0x45, 0x0F, 0xB7); 1119343f845bSAlexei Starovoitov else 1120343f845bSAlexei Starovoitov EMIT2(0x0F, 0xB7); 1121343f845bSAlexei Starovoitov EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); 112262258278SAlexei Starovoitov break; 112362258278SAlexei Starovoitov case 32: 1124a2c7a983SIngo Molnar /* Emit 'bswap eax' to swap lower 4 bytes */ 1125e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 112662258278SAlexei Starovoitov EMIT2(0x41, 0x0F); 112762258278SAlexei Starovoitov else 112862258278SAlexei Starovoitov EMIT1(0x0F); 1129e430f34eSAlexei Starovoitov EMIT1(add_1reg(0xC8, dst_reg)); 113062258278SAlexei Starovoitov break; 113162258278SAlexei Starovoitov case 64: 1132a2c7a983SIngo Molnar /* Emit 'bswap rax' to swap 8 bytes */ 1133e430f34eSAlexei Starovoitov EMIT3(add_1mod(0x48, dst_reg), 0x0F, 1134e430f34eSAlexei Starovoitov add_1reg(0xC8, dst_reg)); 113562258278SAlexei Starovoitov break; 113662258278SAlexei Starovoitov } 113762258278SAlexei Starovoitov break; 113862258278SAlexei Starovoitov 113962258278SAlexei Starovoitov case BPF_ALU | BPF_END | BPF_FROM_LE: 1140343f845bSAlexei Starovoitov switch (imm32) { 1141343f845bSAlexei Starovoitov case 16: 1142a2c7a983SIngo Molnar /* 1143a2c7a983SIngo Molnar * Emit 'movzwl eax, ax' to zero extend 16-bit 1144343f845bSAlexei Starovoitov * into 64 bit 1145343f845bSAlexei Starovoitov */ 1146343f845bSAlexei Starovoitov if (is_ereg(dst_reg)) 1147343f845bSAlexei Starovoitov EMIT3(0x45, 0x0F, 0xB7); 1148343f845bSAlexei Starovoitov else 1149343f845bSAlexei Starovoitov EMIT2(0x0F, 0xB7); 1150343f845bSAlexei Starovoitov EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); 1151343f845bSAlexei Starovoitov break; 1152343f845bSAlexei Starovoitov case 32: 1153a2c7a983SIngo Molnar /* Emit 'mov eax, eax' to clear upper 32-bits */ 1154343f845bSAlexei Starovoitov if (is_ereg(dst_reg)) 1155343f845bSAlexei Starovoitov EMIT1(0x45); 1156343f845bSAlexei Starovoitov EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); 1157343f845bSAlexei Starovoitov break; 1158343f845bSAlexei Starovoitov case 64: 1159343f845bSAlexei Starovoitov /* nop */ 1160343f845bSAlexei Starovoitov break; 1161343f845bSAlexei Starovoitov } 116262258278SAlexei Starovoitov break; 116362258278SAlexei Starovoitov 1164e430f34eSAlexei Starovoitov /* ST: *(u8*)(dst_reg + off) = imm */ 116562258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_B: 1166e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 116762258278SAlexei Starovoitov EMIT2(0x41, 0xC6); 116862258278SAlexei Starovoitov else 116962258278SAlexei Starovoitov EMIT1(0xC6); 117062258278SAlexei Starovoitov goto st; 117162258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_H: 1172e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 117362258278SAlexei Starovoitov EMIT3(0x66, 0x41, 0xC7); 117462258278SAlexei Starovoitov else 117562258278SAlexei Starovoitov EMIT2(0x66, 0xC7); 117662258278SAlexei Starovoitov goto st; 117762258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_W: 1178e430f34eSAlexei Starovoitov if (is_ereg(dst_reg)) 117962258278SAlexei Starovoitov EMIT2(0x41, 0xC7); 118062258278SAlexei Starovoitov else 118162258278SAlexei Starovoitov EMIT1(0xC7); 118262258278SAlexei Starovoitov goto st; 118362258278SAlexei Starovoitov case BPF_ST | BPF_MEM | BPF_DW: 1184e430f34eSAlexei Starovoitov EMIT2(add_1mod(0x48, dst_reg), 0xC7); 118562258278SAlexei Starovoitov 118662258278SAlexei Starovoitov st: if (is_imm8(insn->off)) 1187e430f34eSAlexei Starovoitov EMIT2(add_1reg(0x40, dst_reg), insn->off); 118862258278SAlexei Starovoitov else 1189e430f34eSAlexei Starovoitov EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); 119062258278SAlexei Starovoitov 1191e430f34eSAlexei Starovoitov EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); 119262258278SAlexei Starovoitov break; 119362258278SAlexei Starovoitov 1194e430f34eSAlexei Starovoitov /* STX: *(u8*)(dst_reg + off) = src_reg */ 119562258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_B: 119662258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_H: 119762258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_W: 119862258278SAlexei Starovoitov case BPF_STX | BPF_MEM | BPF_DW: 11993b2744e6SAlexei Starovoitov emit_stx(&prog, BPF_SIZE(insn->code), dst_reg, src_reg, insn->off); 120062258278SAlexei Starovoitov break; 120162258278SAlexei Starovoitov 1202e430f34eSAlexei Starovoitov /* LDX: dst_reg = *(u8*)(src_reg + off) */ 120362258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_B: 12043dec541bSAlexei Starovoitov case BPF_LDX | BPF_PROBE_MEM | BPF_B: 120562258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_H: 12063dec541bSAlexei Starovoitov case BPF_LDX | BPF_PROBE_MEM | BPF_H: 120762258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_W: 12083dec541bSAlexei Starovoitov case BPF_LDX | BPF_PROBE_MEM | BPF_W: 120962258278SAlexei Starovoitov case BPF_LDX | BPF_MEM | BPF_DW: 12103dec541bSAlexei Starovoitov case BPF_LDX | BPF_PROBE_MEM | BPF_DW: 12113b2744e6SAlexei Starovoitov emit_ldx(&prog, BPF_SIZE(insn->code), dst_reg, src_reg, insn->off); 12123dec541bSAlexei Starovoitov if (BPF_MODE(insn->code) == BPF_PROBE_MEM) { 12133dec541bSAlexei Starovoitov struct exception_table_entry *ex; 12143dec541bSAlexei Starovoitov u8 *_insn = image + proglen; 12153dec541bSAlexei Starovoitov s64 delta; 12163dec541bSAlexei Starovoitov 12173dec541bSAlexei Starovoitov if (!bpf_prog->aux->extable) 12183dec541bSAlexei Starovoitov break; 12193dec541bSAlexei Starovoitov 12203dec541bSAlexei Starovoitov if (excnt >= bpf_prog->aux->num_exentries) { 12213dec541bSAlexei Starovoitov pr_err("ex gen bug\n"); 12223dec541bSAlexei Starovoitov return -EFAULT; 12233dec541bSAlexei Starovoitov } 12243dec541bSAlexei Starovoitov ex = &bpf_prog->aux->extable[excnt++]; 12253dec541bSAlexei Starovoitov 12263dec541bSAlexei Starovoitov delta = _insn - (u8 *)&ex->insn; 12273dec541bSAlexei Starovoitov if (!is_simm32(delta)) { 12283dec541bSAlexei Starovoitov pr_err("extable->insn doesn't fit into 32-bit\n"); 12293dec541bSAlexei Starovoitov return -EFAULT; 12303dec541bSAlexei Starovoitov } 12313dec541bSAlexei Starovoitov ex->insn = delta; 12323dec541bSAlexei Starovoitov 12333dec541bSAlexei Starovoitov delta = (u8 *)ex_handler_bpf - (u8 *)&ex->handler; 12343dec541bSAlexei Starovoitov if (!is_simm32(delta)) { 12353dec541bSAlexei Starovoitov pr_err("extable->handler doesn't fit into 32-bit\n"); 12363dec541bSAlexei Starovoitov return -EFAULT; 12373dec541bSAlexei Starovoitov } 12383dec541bSAlexei Starovoitov ex->handler = delta; 12393dec541bSAlexei Starovoitov 12403dec541bSAlexei Starovoitov if (dst_reg > BPF_REG_9) { 12413dec541bSAlexei Starovoitov pr_err("verifier error\n"); 12423dec541bSAlexei Starovoitov return -EFAULT; 12433dec541bSAlexei Starovoitov } 12443dec541bSAlexei Starovoitov /* 12453dec541bSAlexei Starovoitov * Compute size of x86 insn and its target dest x86 register. 12463dec541bSAlexei Starovoitov * ex_handler_bpf() will use lower 8 bits to adjust 12473dec541bSAlexei Starovoitov * pt_regs->ip to jump over this x86 instruction 12483dec541bSAlexei Starovoitov * and upper bits to figure out which pt_regs to zero out. 12493dec541bSAlexei Starovoitov * End result: x86 insn "mov rbx, qword ptr [rax+0x14]" 12503dec541bSAlexei Starovoitov * of 4 bytes will be ignored and rbx will be zero inited. 12513dec541bSAlexei Starovoitov */ 12523dec541bSAlexei Starovoitov ex->fixup = (prog - temp) | (reg2pt_regs[dst_reg] << 8); 12533dec541bSAlexei Starovoitov } 125462258278SAlexei Starovoitov break; 125562258278SAlexei Starovoitov 1256e430f34eSAlexei Starovoitov /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ 125762258278SAlexei Starovoitov case BPF_STX | BPF_XADD | BPF_W: 1258a2c7a983SIngo Molnar /* Emit 'lock add dword ptr [rax + off], eax' */ 1259e430f34eSAlexei Starovoitov if (is_ereg(dst_reg) || is_ereg(src_reg)) 1260e430f34eSAlexei Starovoitov EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); 126162258278SAlexei Starovoitov else 126262258278SAlexei Starovoitov EMIT2(0xF0, 0x01); 126362258278SAlexei Starovoitov goto xadd; 126462258278SAlexei Starovoitov case BPF_STX | BPF_XADD | BPF_DW: 1265e430f34eSAlexei Starovoitov EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); 126611c11d07SBrendan Jackman xadd: 126711c11d07SBrendan Jackman emit_modrm_dstoff(&prog, dst_reg, src_reg, insn->off); 126862258278SAlexei Starovoitov break; 126962258278SAlexei Starovoitov 127062258278SAlexei Starovoitov /* call */ 127162258278SAlexei Starovoitov case BPF_JMP | BPF_CALL: 1272e430f34eSAlexei Starovoitov func = (u8 *) __bpf_call_base + imm32; 1273ebf7d1f5SMaciej Fijalkowski if (tail_call_reachable) { 1274ebf7d1f5SMaciej Fijalkowski EMIT3_off32(0x48, 0x8B, 0x85, 1275ebf7d1f5SMaciej Fijalkowski -(bpf_prog->aux->stack_depth + 8)); 1276ebf7d1f5SMaciej Fijalkowski if (!imm32 || emit_call(&prog, func, image + addrs[i - 1] + 7)) 1277ebf7d1f5SMaciej Fijalkowski return -EINVAL; 1278ebf7d1f5SMaciej Fijalkowski } else { 12793b2744e6SAlexei Starovoitov if (!imm32 || emit_call(&prog, func, image + addrs[i - 1])) 1280f3c2af7bSAlexei Starovoitov return -EINVAL; 1281ebf7d1f5SMaciej Fijalkowski } 128262258278SAlexei Starovoitov break; 128362258278SAlexei Starovoitov 128471189fa9SAlexei Starovoitov case BPF_JMP | BPF_TAIL_CALL: 1285428d5df1SDaniel Borkmann if (imm32) 1286428d5df1SDaniel Borkmann emit_bpf_tail_call_direct(&bpf_prog->aux->poke_tab[imm32 - 1], 1287ebf7d1f5SMaciej Fijalkowski &prog, addrs[i], image, 1288ebf7d1f5SMaciej Fijalkowski callee_regs_used, 1289ebf7d1f5SMaciej Fijalkowski bpf_prog->aux->stack_depth); 1290428d5df1SDaniel Borkmann else 1291ebf7d1f5SMaciej Fijalkowski emit_bpf_tail_call_indirect(&prog, 1292ebf7d1f5SMaciej Fijalkowski callee_regs_used, 1293ebf7d1f5SMaciej Fijalkowski bpf_prog->aux->stack_depth); 1294b52f00e6SAlexei Starovoitov break; 1295b52f00e6SAlexei Starovoitov 129662258278SAlexei Starovoitov /* cond jump */ 129762258278SAlexei Starovoitov case BPF_JMP | BPF_JEQ | BPF_X: 129862258278SAlexei Starovoitov case BPF_JMP | BPF_JNE | BPF_X: 129962258278SAlexei Starovoitov case BPF_JMP | BPF_JGT | BPF_X: 130052afc51eSDaniel Borkmann case BPF_JMP | BPF_JLT | BPF_X: 130162258278SAlexei Starovoitov case BPF_JMP | BPF_JGE | BPF_X: 130252afc51eSDaniel Borkmann case BPF_JMP | BPF_JLE | BPF_X: 130362258278SAlexei Starovoitov case BPF_JMP | BPF_JSGT | BPF_X: 130452afc51eSDaniel Borkmann case BPF_JMP | BPF_JSLT | BPF_X: 130562258278SAlexei Starovoitov case BPF_JMP | BPF_JSGE | BPF_X: 130652afc51eSDaniel Borkmann case BPF_JMP | BPF_JSLE | BPF_X: 13073f5d6525SJiong Wang case BPF_JMP32 | BPF_JEQ | BPF_X: 13083f5d6525SJiong Wang case BPF_JMP32 | BPF_JNE | BPF_X: 13093f5d6525SJiong Wang case BPF_JMP32 | BPF_JGT | BPF_X: 13103f5d6525SJiong Wang case BPF_JMP32 | BPF_JLT | BPF_X: 13113f5d6525SJiong Wang case BPF_JMP32 | BPF_JGE | BPF_X: 13123f5d6525SJiong Wang case BPF_JMP32 | BPF_JLE | BPF_X: 13133f5d6525SJiong Wang case BPF_JMP32 | BPF_JSGT | BPF_X: 13143f5d6525SJiong Wang case BPF_JMP32 | BPF_JSLT | BPF_X: 13153f5d6525SJiong Wang case BPF_JMP32 | BPF_JSGE | BPF_X: 13163f5d6525SJiong Wang case BPF_JMP32 | BPF_JSLE | BPF_X: 1317e430f34eSAlexei Starovoitov /* cmp dst_reg, src_reg */ 1318*74007cfcSBrendan Jackman maybe_emit_mod(&prog, dst_reg, src_reg, 1319*74007cfcSBrendan Jackman BPF_CLASS(insn->code) == BPF_JMP); 13203f5d6525SJiong Wang EMIT2(0x39, add_2reg(0xC0, dst_reg, src_reg)); 132162258278SAlexei Starovoitov goto emit_cond_jmp; 132262258278SAlexei Starovoitov 132362258278SAlexei Starovoitov case BPF_JMP | BPF_JSET | BPF_X: 13243f5d6525SJiong Wang case BPF_JMP32 | BPF_JSET | BPF_X: 1325e430f34eSAlexei Starovoitov /* test dst_reg, src_reg */ 1326*74007cfcSBrendan Jackman maybe_emit_mod(&prog, dst_reg, src_reg, 1327*74007cfcSBrendan Jackman BPF_CLASS(insn->code) == BPF_JMP); 13283f5d6525SJiong Wang EMIT2(0x85, add_2reg(0xC0, dst_reg, src_reg)); 132962258278SAlexei Starovoitov goto emit_cond_jmp; 133062258278SAlexei Starovoitov 133162258278SAlexei Starovoitov case BPF_JMP | BPF_JSET | BPF_K: 13323f5d6525SJiong Wang case BPF_JMP32 | BPF_JSET | BPF_K: 1333e430f34eSAlexei Starovoitov /* test dst_reg, imm32 */ 13343f5d6525SJiong Wang if (BPF_CLASS(insn->code) == BPF_JMP) 1335e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 13363f5d6525SJiong Wang else if (is_ereg(dst_reg)) 13373f5d6525SJiong Wang EMIT1(add_1mod(0x40, dst_reg)); 1338e430f34eSAlexei Starovoitov EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); 133962258278SAlexei Starovoitov goto emit_cond_jmp; 134062258278SAlexei Starovoitov 134162258278SAlexei Starovoitov case BPF_JMP | BPF_JEQ | BPF_K: 134262258278SAlexei Starovoitov case BPF_JMP | BPF_JNE | BPF_K: 134362258278SAlexei Starovoitov case BPF_JMP | BPF_JGT | BPF_K: 134452afc51eSDaniel Borkmann case BPF_JMP | BPF_JLT | BPF_K: 134562258278SAlexei Starovoitov case BPF_JMP | BPF_JGE | BPF_K: 134652afc51eSDaniel Borkmann case BPF_JMP | BPF_JLE | BPF_K: 134762258278SAlexei Starovoitov case BPF_JMP | BPF_JSGT | BPF_K: 134852afc51eSDaniel Borkmann case BPF_JMP | BPF_JSLT | BPF_K: 134962258278SAlexei Starovoitov case BPF_JMP | BPF_JSGE | BPF_K: 135052afc51eSDaniel Borkmann case BPF_JMP | BPF_JSLE | BPF_K: 13513f5d6525SJiong Wang case BPF_JMP32 | BPF_JEQ | BPF_K: 13523f5d6525SJiong Wang case BPF_JMP32 | BPF_JNE | BPF_K: 13533f5d6525SJiong Wang case BPF_JMP32 | BPF_JGT | BPF_K: 13543f5d6525SJiong Wang case BPF_JMP32 | BPF_JLT | BPF_K: 13553f5d6525SJiong Wang case BPF_JMP32 | BPF_JGE | BPF_K: 13563f5d6525SJiong Wang case BPF_JMP32 | BPF_JLE | BPF_K: 13573f5d6525SJiong Wang case BPF_JMP32 | BPF_JSGT | BPF_K: 13583f5d6525SJiong Wang case BPF_JMP32 | BPF_JSLT | BPF_K: 13593f5d6525SJiong Wang case BPF_JMP32 | BPF_JSGE | BPF_K: 13603f5d6525SJiong Wang case BPF_JMP32 | BPF_JSLE | BPF_K: 136138f51c07SDaniel Borkmann /* test dst_reg, dst_reg to save one extra byte */ 136238f51c07SDaniel Borkmann if (imm32 == 0) { 1363*74007cfcSBrendan Jackman maybe_emit_mod(&prog, dst_reg, dst_reg, 1364*74007cfcSBrendan Jackman BPF_CLASS(insn->code) == BPF_JMP); 136538f51c07SDaniel Borkmann EMIT2(0x85, add_2reg(0xC0, dst_reg, dst_reg)); 136638f51c07SDaniel Borkmann goto emit_cond_jmp; 136738f51c07SDaniel Borkmann } 136838f51c07SDaniel Borkmann 1369e430f34eSAlexei Starovoitov /* cmp dst_reg, imm8/32 */ 13703f5d6525SJiong Wang if (BPF_CLASS(insn->code) == BPF_JMP) 1371e430f34eSAlexei Starovoitov EMIT1(add_1mod(0x48, dst_reg)); 13723f5d6525SJiong Wang else if (is_ereg(dst_reg)) 13733f5d6525SJiong Wang EMIT1(add_1mod(0x40, dst_reg)); 137462258278SAlexei Starovoitov 1375e430f34eSAlexei Starovoitov if (is_imm8(imm32)) 1376e430f34eSAlexei Starovoitov EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); 137762258278SAlexei Starovoitov else 1378e430f34eSAlexei Starovoitov EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); 137962258278SAlexei Starovoitov 1380a2c7a983SIngo Molnar emit_cond_jmp: /* Convert BPF opcode to x86 */ 138162258278SAlexei Starovoitov switch (BPF_OP(insn->code)) { 138262258278SAlexei Starovoitov case BPF_JEQ: 138362258278SAlexei Starovoitov jmp_cond = X86_JE; 138462258278SAlexei Starovoitov break; 138562258278SAlexei Starovoitov case BPF_JSET: 138662258278SAlexei Starovoitov case BPF_JNE: 138762258278SAlexei Starovoitov jmp_cond = X86_JNE; 138862258278SAlexei Starovoitov break; 138962258278SAlexei Starovoitov case BPF_JGT: 139062258278SAlexei Starovoitov /* GT is unsigned '>', JA in x86 */ 139162258278SAlexei Starovoitov jmp_cond = X86_JA; 139262258278SAlexei Starovoitov break; 139352afc51eSDaniel Borkmann case BPF_JLT: 139452afc51eSDaniel Borkmann /* LT is unsigned '<', JB in x86 */ 139552afc51eSDaniel Borkmann jmp_cond = X86_JB; 139652afc51eSDaniel Borkmann break; 139762258278SAlexei Starovoitov case BPF_JGE: 139862258278SAlexei Starovoitov /* GE is unsigned '>=', JAE in x86 */ 139962258278SAlexei Starovoitov jmp_cond = X86_JAE; 140062258278SAlexei Starovoitov break; 140152afc51eSDaniel Borkmann case BPF_JLE: 140252afc51eSDaniel Borkmann /* LE is unsigned '<=', JBE in x86 */ 140352afc51eSDaniel Borkmann jmp_cond = X86_JBE; 140452afc51eSDaniel Borkmann break; 140562258278SAlexei Starovoitov case BPF_JSGT: 1406a2c7a983SIngo Molnar /* Signed '>', GT in x86 */ 140762258278SAlexei Starovoitov jmp_cond = X86_JG; 140862258278SAlexei Starovoitov break; 140952afc51eSDaniel Borkmann case BPF_JSLT: 1410a2c7a983SIngo Molnar /* Signed '<', LT in x86 */ 141152afc51eSDaniel Borkmann jmp_cond = X86_JL; 141252afc51eSDaniel Borkmann break; 141362258278SAlexei Starovoitov case BPF_JSGE: 1414a2c7a983SIngo Molnar /* Signed '>=', GE in x86 */ 141562258278SAlexei Starovoitov jmp_cond = X86_JGE; 141662258278SAlexei Starovoitov break; 141752afc51eSDaniel Borkmann case BPF_JSLE: 1418a2c7a983SIngo Molnar /* Signed '<=', LE in x86 */ 141952afc51eSDaniel Borkmann jmp_cond = X86_JLE; 142052afc51eSDaniel Borkmann break; 1421a2c7a983SIngo Molnar default: /* to silence GCC warning */ 142262258278SAlexei Starovoitov return -EFAULT; 142362258278SAlexei Starovoitov } 142462258278SAlexei Starovoitov jmp_offset = addrs[i + insn->off] - addrs[i]; 142562258278SAlexei Starovoitov if (is_imm8(jmp_offset)) { 142662258278SAlexei Starovoitov EMIT2(jmp_cond, jmp_offset); 142762258278SAlexei Starovoitov } else if (is_simm32(jmp_offset)) { 142862258278SAlexei Starovoitov EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); 14293b58908aSEric Dumazet } else { 143062258278SAlexei Starovoitov pr_err("cond_jmp gen bug %llx\n", jmp_offset); 143162258278SAlexei Starovoitov return -EFAULT; 14323b58908aSEric Dumazet } 143362258278SAlexei Starovoitov 14343b58908aSEric Dumazet break; 143562258278SAlexei Starovoitov 143662258278SAlexei Starovoitov case BPF_JMP | BPF_JA: 14371612a981SGianluca Borello if (insn->off == -1) 14381612a981SGianluca Borello /* -1 jmp instructions will always jump 14391612a981SGianluca Borello * backwards two bytes. Explicitly handling 14401612a981SGianluca Borello * this case avoids wasting too many passes 14411612a981SGianluca Borello * when there are long sequences of replaced 14421612a981SGianluca Borello * dead code. 14431612a981SGianluca Borello */ 14441612a981SGianluca Borello jmp_offset = -2; 14451612a981SGianluca Borello else 144662258278SAlexei Starovoitov jmp_offset = addrs[i + insn->off] - addrs[i]; 14471612a981SGianluca Borello 144862258278SAlexei Starovoitov if (!jmp_offset) 1449a2c7a983SIngo Molnar /* Optimize out nop jumps */ 145062258278SAlexei Starovoitov break; 145162258278SAlexei Starovoitov emit_jmp: 145262258278SAlexei Starovoitov if (is_imm8(jmp_offset)) { 145362258278SAlexei Starovoitov EMIT2(0xEB, jmp_offset); 145462258278SAlexei Starovoitov } else if (is_simm32(jmp_offset)) { 145562258278SAlexei Starovoitov EMIT1_off32(0xE9, jmp_offset); 145662258278SAlexei Starovoitov } else { 145762258278SAlexei Starovoitov pr_err("jmp gen bug %llx\n", jmp_offset); 145862258278SAlexei Starovoitov return -EFAULT; 14593b58908aSEric Dumazet } 146062258278SAlexei Starovoitov break; 146162258278SAlexei Starovoitov 146262258278SAlexei Starovoitov case BPF_JMP | BPF_EXIT: 1463769e0de6SAlexei Starovoitov if (seen_exit) { 146462258278SAlexei Starovoitov jmp_offset = ctx->cleanup_addr - addrs[i]; 146562258278SAlexei Starovoitov goto emit_jmp; 146662258278SAlexei Starovoitov } 1467769e0de6SAlexei Starovoitov seen_exit = true; 1468a2c7a983SIngo Molnar /* Update cleanup_addr */ 146962258278SAlexei Starovoitov ctx->cleanup_addr = proglen; 1470ebf7d1f5SMaciej Fijalkowski pop_callee_regs(&prog, callee_regs_used); 147162258278SAlexei Starovoitov EMIT1(0xC9); /* leave */ 147262258278SAlexei Starovoitov EMIT1(0xC3); /* ret */ 14730a14842fSEric Dumazet break; 14740a14842fSEric Dumazet 14750a14842fSEric Dumazet default: 1476a2c7a983SIngo Molnar /* 1477a2c7a983SIngo Molnar * By design x86-64 JIT should support all BPF instructions. 147862258278SAlexei Starovoitov * This error will be seen if new instruction was added 1479a2c7a983SIngo Molnar * to the interpreter, but not to the JIT, or if there is 1480a2c7a983SIngo Molnar * junk in bpf_prog. 148162258278SAlexei Starovoitov */ 148262258278SAlexei Starovoitov pr_err("bpf_jit: unknown opcode %02x\n", insn->code); 1483f3c2af7bSAlexei Starovoitov return -EINVAL; 14840a14842fSEric Dumazet } 148562258278SAlexei Starovoitov 14860a14842fSEric Dumazet ilen = prog - temp; 1487e0ee9c12SAlexei Starovoitov if (ilen > BPF_MAX_INSN_SIZE) { 14889383191dSDaniel Borkmann pr_err("bpf_jit: fatal insn size error\n"); 1489e0ee9c12SAlexei Starovoitov return -EFAULT; 1490e0ee9c12SAlexei Starovoitov } 1491e0ee9c12SAlexei Starovoitov 14920a14842fSEric Dumazet if (image) { 14930a14842fSEric Dumazet if (unlikely(proglen + ilen > oldproglen)) { 14949383191dSDaniel Borkmann pr_err("bpf_jit: fatal error\n"); 1495f3c2af7bSAlexei Starovoitov return -EFAULT; 14960a14842fSEric Dumazet } 14970a14842fSEric Dumazet memcpy(image + proglen, temp, ilen); 14980a14842fSEric Dumazet } 14990a14842fSEric Dumazet proglen += ilen; 15000a14842fSEric Dumazet addrs[i] = proglen; 15010a14842fSEric Dumazet prog = temp; 15020a14842fSEric Dumazet } 15033dec541bSAlexei Starovoitov 15043dec541bSAlexei Starovoitov if (image && excnt != bpf_prog->aux->num_exentries) { 15053dec541bSAlexei Starovoitov pr_err("extable is not populated\n"); 15063dec541bSAlexei Starovoitov return -EFAULT; 15073dec541bSAlexei Starovoitov } 1508f3c2af7bSAlexei Starovoitov return proglen; 1509f3c2af7bSAlexei Starovoitov } 1510f3c2af7bSAlexei Starovoitov 151185d33df3SMartin KaFai Lau static void save_regs(const struct btf_func_model *m, u8 **prog, int nr_args, 1512fec56f58SAlexei Starovoitov int stack_size) 1513fec56f58SAlexei Starovoitov { 1514fec56f58SAlexei Starovoitov int i; 1515fec56f58SAlexei Starovoitov /* Store function arguments to stack. 1516fec56f58SAlexei Starovoitov * For a function that accepts two pointers the sequence will be: 1517fec56f58SAlexei Starovoitov * mov QWORD PTR [rbp-0x10],rdi 1518fec56f58SAlexei Starovoitov * mov QWORD PTR [rbp-0x8],rsi 1519fec56f58SAlexei Starovoitov */ 1520fec56f58SAlexei Starovoitov for (i = 0; i < min(nr_args, 6); i++) 1521fec56f58SAlexei Starovoitov emit_stx(prog, bytes_to_bpf_size(m->arg_size[i]), 1522fec56f58SAlexei Starovoitov BPF_REG_FP, 1523fec56f58SAlexei Starovoitov i == 5 ? X86_REG_R9 : BPF_REG_1 + i, 1524fec56f58SAlexei Starovoitov -(stack_size - i * 8)); 1525fec56f58SAlexei Starovoitov } 1526fec56f58SAlexei Starovoitov 152785d33df3SMartin KaFai Lau static void restore_regs(const struct btf_func_model *m, u8 **prog, int nr_args, 1528fec56f58SAlexei Starovoitov int stack_size) 1529fec56f58SAlexei Starovoitov { 1530fec56f58SAlexei Starovoitov int i; 1531fec56f58SAlexei Starovoitov 1532fec56f58SAlexei Starovoitov /* Restore function arguments from stack. 1533fec56f58SAlexei Starovoitov * For a function that accepts two pointers the sequence will be: 1534fec56f58SAlexei Starovoitov * EMIT4(0x48, 0x8B, 0x7D, 0xF0); mov rdi,QWORD PTR [rbp-0x10] 1535fec56f58SAlexei Starovoitov * EMIT4(0x48, 0x8B, 0x75, 0xF8); mov rsi,QWORD PTR [rbp-0x8] 1536fec56f58SAlexei Starovoitov */ 1537fec56f58SAlexei Starovoitov for (i = 0; i < min(nr_args, 6); i++) 1538fec56f58SAlexei Starovoitov emit_ldx(prog, bytes_to_bpf_size(m->arg_size[i]), 1539fec56f58SAlexei Starovoitov i == 5 ? X86_REG_R9 : BPF_REG_1 + i, 1540fec56f58SAlexei Starovoitov BPF_REG_FP, 1541fec56f58SAlexei Starovoitov -(stack_size - i * 8)); 1542fec56f58SAlexei Starovoitov } 1543fec56f58SAlexei Starovoitov 15447e639208SKP Singh static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, 1545ae240823SKP Singh struct bpf_prog *p, int stack_size, bool mod_ret) 1546fec56f58SAlexei Starovoitov { 1547fec56f58SAlexei Starovoitov u8 *prog = *pprog; 15487e639208SKP Singh int cnt = 0; 1549fec56f58SAlexei Starovoitov 15501e6c62a8SAlexei Starovoitov if (p->aux->sleepable) { 15511e6c62a8SAlexei Starovoitov if (emit_call(&prog, __bpf_prog_enter_sleepable, prog)) 15521e6c62a8SAlexei Starovoitov return -EINVAL; 15531e6c62a8SAlexei Starovoitov } else { 1554fec56f58SAlexei Starovoitov if (emit_call(&prog, __bpf_prog_enter, prog)) 1555fec56f58SAlexei Starovoitov return -EINVAL; 1556fec56f58SAlexei Starovoitov /* remember prog start time returned by __bpf_prog_enter */ 1557fec56f58SAlexei Starovoitov emit_mov_reg(&prog, true, BPF_REG_6, BPF_REG_0); 15581e6c62a8SAlexei Starovoitov } 1559fec56f58SAlexei Starovoitov 1560fec56f58SAlexei Starovoitov /* arg1: lea rdi, [rbp - stack_size] */ 1561fec56f58SAlexei Starovoitov EMIT4(0x48, 0x8D, 0x7D, -stack_size); 1562fec56f58SAlexei Starovoitov /* arg2: progs[i]->insnsi for interpreter */ 15637e639208SKP Singh if (!p->jited) 1564fec56f58SAlexei Starovoitov emit_mov_imm64(&prog, BPF_REG_2, 15657e639208SKP Singh (long) p->insnsi >> 32, 15667e639208SKP Singh (u32) (long) p->insnsi); 1567fec56f58SAlexei Starovoitov /* call JITed bpf program or interpreter */ 15687e639208SKP Singh if (emit_call(&prog, p->bpf_func, prog)) 1569fec56f58SAlexei Starovoitov return -EINVAL; 1570fec56f58SAlexei Starovoitov 1571ae240823SKP Singh /* BPF_TRAMP_MODIFY_RETURN trampolines can modify the return 1572ae240823SKP Singh * of the previous call which is then passed on the stack to 1573ae240823SKP Singh * the next BPF program. 1574ae240823SKP Singh */ 1575ae240823SKP Singh if (mod_ret) 1576ae240823SKP Singh emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8); 1577ae240823SKP Singh 15781e6c62a8SAlexei Starovoitov if (p->aux->sleepable) { 15791e6c62a8SAlexei Starovoitov if (emit_call(&prog, __bpf_prog_exit_sleepable, prog)) 15801e6c62a8SAlexei Starovoitov return -EINVAL; 15811e6c62a8SAlexei Starovoitov } else { 1582fec56f58SAlexei Starovoitov /* arg1: mov rdi, progs[i] */ 15837e639208SKP Singh emit_mov_imm64(&prog, BPF_REG_1, (long) p >> 32, 15847e639208SKP Singh (u32) (long) p); 1585fec56f58SAlexei Starovoitov /* arg2: mov rsi, rbx <- start time in nsec */ 1586fec56f58SAlexei Starovoitov emit_mov_reg(&prog, true, BPF_REG_2, BPF_REG_6); 1587fec56f58SAlexei Starovoitov if (emit_call(&prog, __bpf_prog_exit, prog)) 1588fec56f58SAlexei Starovoitov return -EINVAL; 15891e6c62a8SAlexei Starovoitov } 15907e639208SKP Singh 15917e639208SKP Singh *pprog = prog; 15927e639208SKP Singh return 0; 15937e639208SKP Singh } 15947e639208SKP Singh 15957e639208SKP Singh static void emit_nops(u8 **pprog, unsigned int len) 15967e639208SKP Singh { 15977e639208SKP Singh unsigned int i, noplen; 15987e639208SKP Singh u8 *prog = *pprog; 15997e639208SKP Singh int cnt = 0; 16007e639208SKP Singh 16017e639208SKP Singh while (len > 0) { 16027e639208SKP Singh noplen = len; 16037e639208SKP Singh 16047e639208SKP Singh if (noplen > ASM_NOP_MAX) 16057e639208SKP Singh noplen = ASM_NOP_MAX; 16067e639208SKP Singh 16077e639208SKP Singh for (i = 0; i < noplen; i++) 16087e639208SKP Singh EMIT1(ideal_nops[noplen][i]); 16097e639208SKP Singh len -= noplen; 16107e639208SKP Singh } 16117e639208SKP Singh 16127e639208SKP Singh *pprog = prog; 16137e639208SKP Singh } 16147e639208SKP Singh 16157e639208SKP Singh static void emit_align(u8 **pprog, u32 align) 16167e639208SKP Singh { 16177e639208SKP Singh u8 *target, *prog = *pprog; 16187e639208SKP Singh 16197e639208SKP Singh target = PTR_ALIGN(prog, align); 16207e639208SKP Singh if (target != prog) 16217e639208SKP Singh emit_nops(&prog, target - prog); 16227e639208SKP Singh 16237e639208SKP Singh *pprog = prog; 16247e639208SKP Singh } 16257e639208SKP Singh 16267e639208SKP Singh static int emit_cond_near_jump(u8 **pprog, void *func, void *ip, u8 jmp_cond) 16277e639208SKP Singh { 16287e639208SKP Singh u8 *prog = *pprog; 16297e639208SKP Singh int cnt = 0; 16307e639208SKP Singh s64 offset; 16317e639208SKP Singh 16327e639208SKP Singh offset = func - (ip + 2 + 4); 16337e639208SKP Singh if (!is_simm32(offset)) { 16347e639208SKP Singh pr_err("Target %p is out of range\n", func); 16357e639208SKP Singh return -EINVAL; 16367e639208SKP Singh } 16377e639208SKP Singh EMIT2_off32(0x0F, jmp_cond + 0x10, offset); 16387e639208SKP Singh *pprog = prog; 16397e639208SKP Singh return 0; 16407e639208SKP Singh } 16417e639208SKP Singh 16427e639208SKP Singh static int invoke_bpf(const struct btf_func_model *m, u8 **pprog, 16437e639208SKP Singh struct bpf_tramp_progs *tp, int stack_size) 16447e639208SKP Singh { 16457e639208SKP Singh int i; 16467e639208SKP Singh u8 *prog = *pprog; 16477e639208SKP Singh 16487e639208SKP Singh for (i = 0; i < tp->nr_progs; i++) { 1649ae240823SKP Singh if (invoke_bpf_prog(m, &prog, tp->progs[i], stack_size, false)) 16507e639208SKP Singh return -EINVAL; 1651fec56f58SAlexei Starovoitov } 1652fec56f58SAlexei Starovoitov *pprog = prog; 1653fec56f58SAlexei Starovoitov return 0; 1654fec56f58SAlexei Starovoitov } 1655fec56f58SAlexei Starovoitov 1656ae240823SKP Singh static int invoke_bpf_mod_ret(const struct btf_func_model *m, u8 **pprog, 1657ae240823SKP Singh struct bpf_tramp_progs *tp, int stack_size, 1658ae240823SKP Singh u8 **branches) 1659ae240823SKP Singh { 1660ae240823SKP Singh u8 *prog = *pprog; 166113fac1d8SAlexei Starovoitov int i, cnt = 0; 1662ae240823SKP Singh 1663ae240823SKP Singh /* The first fmod_ret program will receive a garbage return value. 1664ae240823SKP Singh * Set this to 0 to avoid confusing the program. 1665ae240823SKP Singh */ 1666ae240823SKP Singh emit_mov_imm32(&prog, false, BPF_REG_0, 0); 1667ae240823SKP Singh emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8); 1668ae240823SKP Singh for (i = 0; i < tp->nr_progs; i++) { 1669ae240823SKP Singh if (invoke_bpf_prog(m, &prog, tp->progs[i], stack_size, true)) 1670ae240823SKP Singh return -EINVAL; 1671ae240823SKP Singh 167213fac1d8SAlexei Starovoitov /* mod_ret prog stored return value into [rbp - 8]. Emit: 167313fac1d8SAlexei Starovoitov * if (*(u64 *)(rbp - 8) != 0) 1674ae240823SKP Singh * goto do_fexit; 1675ae240823SKP Singh */ 167613fac1d8SAlexei Starovoitov /* cmp QWORD PTR [rbp - 0x8], 0x0 */ 167713fac1d8SAlexei Starovoitov EMIT4(0x48, 0x83, 0x7d, 0xf8); EMIT1(0x00); 1678ae240823SKP Singh 1679ae240823SKP Singh /* Save the location of the branch and Generate 6 nops 1680ae240823SKP Singh * (4 bytes for an offset and 2 bytes for the jump) These nops 1681ae240823SKP Singh * are replaced with a conditional jump once do_fexit (i.e. the 1682ae240823SKP Singh * start of the fexit invocation) is finalized. 1683ae240823SKP Singh */ 1684ae240823SKP Singh branches[i] = prog; 1685ae240823SKP Singh emit_nops(&prog, 4 + 2); 1686ae240823SKP Singh } 1687ae240823SKP Singh 1688ae240823SKP Singh *pprog = prog; 1689ae240823SKP Singh return 0; 1690ae240823SKP Singh } 1691ae240823SKP Singh 1692fec56f58SAlexei Starovoitov /* Example: 1693fec56f58SAlexei Starovoitov * __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev); 1694fec56f58SAlexei Starovoitov * its 'struct btf_func_model' will be nr_args=2 1695fec56f58SAlexei Starovoitov * The assembly code when eth_type_trans is executing after trampoline: 1696fec56f58SAlexei Starovoitov * 1697fec56f58SAlexei Starovoitov * push rbp 1698fec56f58SAlexei Starovoitov * mov rbp, rsp 1699fec56f58SAlexei Starovoitov * sub rsp, 16 // space for skb and dev 1700fec56f58SAlexei Starovoitov * push rbx // temp regs to pass start time 1701fec56f58SAlexei Starovoitov * mov qword ptr [rbp - 16], rdi // save skb pointer to stack 1702fec56f58SAlexei Starovoitov * mov qword ptr [rbp - 8], 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 in bpf stats are enabled 1705fec56f58SAlexei Starovoitov * lea rdi, [rbp - 16] // R1==ctx of bpf prog 1706fec56f58SAlexei Starovoitov * call addr_of_jited_FENTRY_prog 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 - 16] // restore skb pointer from stack 1711fec56f58SAlexei Starovoitov * mov rsi, qword ptr [rbp - 8] // restore dev pointer from stack 1712fec56f58SAlexei Starovoitov * pop rbx 1713fec56f58SAlexei Starovoitov * leave 1714fec56f58SAlexei Starovoitov * ret 1715fec56f58SAlexei Starovoitov * 1716fec56f58SAlexei Starovoitov * eth_type_trans has 5 byte nop at the beginning. These 5 bytes will be 1717fec56f58SAlexei Starovoitov * replaced with 'call generated_bpf_trampoline'. When it returns 1718fec56f58SAlexei Starovoitov * eth_type_trans will continue executing with original skb and dev pointers. 1719fec56f58SAlexei Starovoitov * 1720fec56f58SAlexei Starovoitov * The assembly code when eth_type_trans is called from trampoline: 1721fec56f58SAlexei Starovoitov * 1722fec56f58SAlexei Starovoitov * push rbp 1723fec56f58SAlexei Starovoitov * mov rbp, rsp 1724fec56f58SAlexei Starovoitov * sub rsp, 24 // space for skb, dev, return value 1725fec56f58SAlexei Starovoitov * push rbx // temp regs to pass start time 1726fec56f58SAlexei Starovoitov * mov qword ptr [rbp - 24], rdi // save skb pointer to stack 1727fec56f58SAlexei Starovoitov * mov qword ptr [rbp - 16], rsi // save dev pointer to stack 1728fec56f58SAlexei Starovoitov * call __bpf_prog_enter // rcu_read_lock and preempt_disable 1729fec56f58SAlexei Starovoitov * mov rbx, rax // remember start time if bpf stats are enabled 1730fec56f58SAlexei Starovoitov * lea rdi, [rbp - 24] // R1==ctx of bpf prog 1731fec56f58SAlexei Starovoitov * call addr_of_jited_FENTRY_prog // bpf prog can access skb and dev 1732fec56f58SAlexei Starovoitov * movabsq rdi, 64bit_addr_of_struct_bpf_prog // unused if bpf stats are off 1733fec56f58SAlexei Starovoitov * mov rsi, rbx // prog start time 1734fec56f58SAlexei Starovoitov * call __bpf_prog_exit // rcu_read_unlock, preempt_enable and stats math 1735fec56f58SAlexei Starovoitov * mov rdi, qword ptr [rbp - 24] // restore skb pointer from stack 1736fec56f58SAlexei Starovoitov * mov rsi, qword ptr [rbp - 16] // restore dev pointer from stack 1737fec56f58SAlexei Starovoitov * call eth_type_trans+5 // execute body of eth_type_trans 1738fec56f58SAlexei Starovoitov * mov qword ptr [rbp - 8], rax // save return value 1739fec56f58SAlexei Starovoitov * call __bpf_prog_enter // rcu_read_lock and preempt_disable 1740fec56f58SAlexei Starovoitov * mov rbx, rax // remember start time in bpf stats are enabled 1741fec56f58SAlexei Starovoitov * lea rdi, [rbp - 24] // R1==ctx of bpf prog 1742fec56f58SAlexei Starovoitov * call addr_of_jited_FEXIT_prog // bpf prog can access skb, dev, return value 1743fec56f58SAlexei Starovoitov * movabsq rdi, 64bit_addr_of_struct_bpf_prog // unused if bpf stats are off 1744fec56f58SAlexei Starovoitov * mov rsi, rbx // prog start time 1745fec56f58SAlexei Starovoitov * call __bpf_prog_exit // rcu_read_unlock, preempt_enable and stats math 1746fec56f58SAlexei Starovoitov * mov rax, qword ptr [rbp - 8] // restore eth_type_trans's return value 1747fec56f58SAlexei Starovoitov * pop rbx 1748fec56f58SAlexei Starovoitov * leave 1749fec56f58SAlexei Starovoitov * add rsp, 8 // skip eth_type_trans's frame 1750fec56f58SAlexei Starovoitov * ret // return to its caller 1751fec56f58SAlexei Starovoitov */ 175285d33df3SMartin KaFai Lau int arch_prepare_bpf_trampoline(void *image, void *image_end, 175385d33df3SMartin KaFai Lau const struct btf_func_model *m, u32 flags, 175488fd9e53SKP Singh struct bpf_tramp_progs *tprogs, 1755fec56f58SAlexei Starovoitov void *orig_call) 1756fec56f58SAlexei Starovoitov { 1757ae240823SKP Singh int ret, i, cnt = 0, nr_args = m->nr_args; 1758fec56f58SAlexei Starovoitov int stack_size = nr_args * 8; 175988fd9e53SKP Singh struct bpf_tramp_progs *fentry = &tprogs[BPF_TRAMP_FENTRY]; 176088fd9e53SKP Singh struct bpf_tramp_progs *fexit = &tprogs[BPF_TRAMP_FEXIT]; 1761ae240823SKP Singh struct bpf_tramp_progs *fmod_ret = &tprogs[BPF_TRAMP_MODIFY_RETURN]; 1762ae240823SKP Singh u8 **branches = NULL; 1763fec56f58SAlexei Starovoitov u8 *prog; 1764fec56f58SAlexei Starovoitov 1765fec56f58SAlexei Starovoitov /* x86-64 supports up to 6 arguments. 7+ can be added in the future */ 1766fec56f58SAlexei Starovoitov if (nr_args > 6) 1767fec56f58SAlexei Starovoitov return -ENOTSUPP; 1768fec56f58SAlexei Starovoitov 1769fec56f58SAlexei Starovoitov if ((flags & BPF_TRAMP_F_RESTORE_REGS) && 1770fec56f58SAlexei Starovoitov (flags & BPF_TRAMP_F_SKIP_FRAME)) 1771fec56f58SAlexei Starovoitov return -EINVAL; 1772fec56f58SAlexei Starovoitov 1773fec56f58SAlexei Starovoitov if (flags & BPF_TRAMP_F_CALL_ORIG) 1774fec56f58SAlexei Starovoitov stack_size += 8; /* room for return value of orig_call */ 1775fec56f58SAlexei Starovoitov 1776fec56f58SAlexei Starovoitov if (flags & BPF_TRAMP_F_SKIP_FRAME) 1777fec56f58SAlexei Starovoitov /* skip patched call instruction and point orig_call to actual 1778fec56f58SAlexei Starovoitov * body of the kernel function. 1779fec56f58SAlexei Starovoitov */ 17804b3da77bSDaniel Borkmann orig_call += X86_PATCH_SIZE; 1781fec56f58SAlexei Starovoitov 1782fec56f58SAlexei Starovoitov prog = image; 1783fec56f58SAlexei Starovoitov 1784fec56f58SAlexei Starovoitov EMIT1(0x55); /* push rbp */ 1785fec56f58SAlexei Starovoitov EMIT3(0x48, 0x89, 0xE5); /* mov rbp, rsp */ 1786fec56f58SAlexei Starovoitov EMIT4(0x48, 0x83, 0xEC, stack_size); /* sub rsp, stack_size */ 1787fec56f58SAlexei Starovoitov EMIT1(0x53); /* push rbx */ 1788fec56f58SAlexei Starovoitov 1789fec56f58SAlexei Starovoitov save_regs(m, &prog, nr_args, stack_size); 1790fec56f58SAlexei Starovoitov 179188fd9e53SKP Singh if (fentry->nr_progs) 179288fd9e53SKP Singh if (invoke_bpf(m, &prog, fentry, stack_size)) 1793fec56f58SAlexei Starovoitov return -EINVAL; 1794fec56f58SAlexei Starovoitov 1795ae240823SKP Singh if (fmod_ret->nr_progs) { 1796ae240823SKP Singh branches = kcalloc(fmod_ret->nr_progs, sizeof(u8 *), 1797ae240823SKP Singh GFP_KERNEL); 1798ae240823SKP Singh if (!branches) 1799ae240823SKP Singh return -ENOMEM; 1800ae240823SKP Singh 1801ae240823SKP Singh if (invoke_bpf_mod_ret(m, &prog, fmod_ret, stack_size, 1802ae240823SKP Singh branches)) { 1803ae240823SKP Singh ret = -EINVAL; 1804ae240823SKP Singh goto cleanup; 1805ae240823SKP Singh } 1806ae240823SKP Singh } 1807ae240823SKP Singh 1808fec56f58SAlexei Starovoitov if (flags & BPF_TRAMP_F_CALL_ORIG) { 1809ae240823SKP Singh if (fentry->nr_progs || fmod_ret->nr_progs) 1810fec56f58SAlexei Starovoitov restore_regs(m, &prog, nr_args, stack_size); 1811fec56f58SAlexei Starovoitov 1812fec56f58SAlexei Starovoitov /* call original function */ 1813ae240823SKP Singh if (emit_call(&prog, orig_call, prog)) { 1814ae240823SKP Singh ret = -EINVAL; 1815ae240823SKP Singh goto cleanup; 1816ae240823SKP Singh } 1817fec56f58SAlexei Starovoitov /* remember return value in a stack for bpf prog to access */ 1818fec56f58SAlexei Starovoitov emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8); 1819fec56f58SAlexei Starovoitov } 1820fec56f58SAlexei Starovoitov 1821ae240823SKP Singh if (fmod_ret->nr_progs) { 1822ae240823SKP Singh /* From Intel 64 and IA-32 Architectures Optimization 1823ae240823SKP Singh * Reference Manual, 3.4.1.4 Code Alignment, Assembly/Compiler 1824ae240823SKP Singh * Coding Rule 11: All branch targets should be 16-byte 1825ae240823SKP Singh * aligned. 1826ae240823SKP Singh */ 1827ae240823SKP Singh emit_align(&prog, 16); 1828ae240823SKP Singh /* Update the branches saved in invoke_bpf_mod_ret with the 1829ae240823SKP Singh * aligned address of do_fexit. 1830ae240823SKP Singh */ 1831ae240823SKP Singh for (i = 0; i < fmod_ret->nr_progs; i++) 1832ae240823SKP Singh emit_cond_near_jump(&branches[i], prog, branches[i], 1833ae240823SKP Singh X86_JNE); 1834ae240823SKP Singh } 1835ae240823SKP Singh 183688fd9e53SKP Singh if (fexit->nr_progs) 1837ae240823SKP Singh if (invoke_bpf(m, &prog, fexit, stack_size)) { 1838ae240823SKP Singh ret = -EINVAL; 1839ae240823SKP Singh goto cleanup; 1840ae240823SKP Singh } 1841fec56f58SAlexei Starovoitov 1842fec56f58SAlexei Starovoitov if (flags & BPF_TRAMP_F_RESTORE_REGS) 1843fec56f58SAlexei Starovoitov restore_regs(m, &prog, nr_args, stack_size); 1844fec56f58SAlexei Starovoitov 1845ae240823SKP Singh /* This needs to be done regardless. If there were fmod_ret programs, 1846ae240823SKP Singh * the return value is only updated on the stack and still needs to be 1847ae240823SKP Singh * restored to R0. 1848ae240823SKP Singh */ 1849fec56f58SAlexei Starovoitov if (flags & BPF_TRAMP_F_CALL_ORIG) 1850fec56f58SAlexei Starovoitov /* restore original return value back into RAX */ 1851fec56f58SAlexei Starovoitov emit_ldx(&prog, BPF_DW, BPF_REG_0, BPF_REG_FP, -8); 1852fec56f58SAlexei Starovoitov 1853fec56f58SAlexei Starovoitov EMIT1(0x5B); /* pop rbx */ 1854fec56f58SAlexei Starovoitov EMIT1(0xC9); /* leave */ 1855fec56f58SAlexei Starovoitov if (flags & BPF_TRAMP_F_SKIP_FRAME) 1856fec56f58SAlexei Starovoitov /* skip our return address and return to parent */ 1857fec56f58SAlexei Starovoitov EMIT4(0x48, 0x83, 0xC4, 8); /* add rsp, 8 */ 1858fec56f58SAlexei Starovoitov EMIT1(0xC3); /* ret */ 185985d33df3SMartin KaFai Lau /* Make sure the trampoline generation logic doesn't overflow */ 1860ae240823SKP Singh if (WARN_ON_ONCE(prog > (u8 *)image_end - BPF_INSN_SAFETY)) { 1861ae240823SKP Singh ret = -EFAULT; 1862ae240823SKP Singh goto cleanup; 1863ae240823SKP Singh } 1864ae240823SKP Singh ret = prog - (u8 *)image; 1865ae240823SKP Singh 1866ae240823SKP Singh cleanup: 1867ae240823SKP Singh kfree(branches); 1868ae240823SKP Singh return ret; 1869fec56f58SAlexei Starovoitov } 1870fec56f58SAlexei Starovoitov 187175ccbef6SBjörn Töpel static int emit_fallback_jump(u8 **pprog) 187275ccbef6SBjörn Töpel { 187375ccbef6SBjörn Töpel u8 *prog = *pprog; 187475ccbef6SBjörn Töpel int err = 0; 187575ccbef6SBjörn Töpel 187675ccbef6SBjörn Töpel #ifdef CONFIG_RETPOLINE 187775ccbef6SBjörn Töpel /* Note that this assumes the the compiler uses external 187875ccbef6SBjörn Töpel * thunks for indirect calls. Both clang and GCC use the same 187975ccbef6SBjörn Töpel * naming convention for external thunks. 188075ccbef6SBjörn Töpel */ 188175ccbef6SBjörn Töpel err = emit_jump(&prog, __x86_indirect_thunk_rdx, prog); 188275ccbef6SBjörn Töpel #else 188375ccbef6SBjörn Töpel int cnt = 0; 188475ccbef6SBjörn Töpel 188575ccbef6SBjörn Töpel EMIT2(0xFF, 0xE2); /* jmp rdx */ 188675ccbef6SBjörn Töpel #endif 188775ccbef6SBjörn Töpel *pprog = prog; 188875ccbef6SBjörn Töpel return err; 188975ccbef6SBjörn Töpel } 189075ccbef6SBjörn Töpel 189175ccbef6SBjörn Töpel static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs) 189275ccbef6SBjörn Töpel { 18937e639208SKP Singh u8 *jg_reloc, *prog = *pprog; 189475ccbef6SBjörn Töpel int pivot, err, jg_bytes = 1, cnt = 0; 189575ccbef6SBjörn Töpel s64 jg_offset; 189675ccbef6SBjörn Töpel 189775ccbef6SBjörn Töpel if (a == b) { 189875ccbef6SBjörn Töpel /* Leaf node of recursion, i.e. not a range of indices 189975ccbef6SBjörn Töpel * anymore. 190075ccbef6SBjörn Töpel */ 190175ccbef6SBjörn Töpel EMIT1(add_1mod(0x48, BPF_REG_3)); /* cmp rdx,func */ 190275ccbef6SBjörn Töpel if (!is_simm32(progs[a])) 190375ccbef6SBjörn Töpel return -1; 190475ccbef6SBjörn Töpel EMIT2_off32(0x81, add_1reg(0xF8, BPF_REG_3), 190575ccbef6SBjörn Töpel progs[a]); 190675ccbef6SBjörn Töpel err = emit_cond_near_jump(&prog, /* je func */ 190775ccbef6SBjörn Töpel (void *)progs[a], prog, 190875ccbef6SBjörn Töpel X86_JE); 190975ccbef6SBjörn Töpel if (err) 191075ccbef6SBjörn Töpel return err; 191175ccbef6SBjörn Töpel 191275ccbef6SBjörn Töpel err = emit_fallback_jump(&prog); /* jmp thunk/indirect */ 191375ccbef6SBjörn Töpel if (err) 191475ccbef6SBjörn Töpel return err; 191575ccbef6SBjörn Töpel 191675ccbef6SBjörn Töpel *pprog = prog; 191775ccbef6SBjörn Töpel return 0; 191875ccbef6SBjörn Töpel } 191975ccbef6SBjörn Töpel 192075ccbef6SBjörn Töpel /* Not a leaf node, so we pivot, and recursively descend into 192175ccbef6SBjörn Töpel * the lower and upper ranges. 192275ccbef6SBjörn Töpel */ 192375ccbef6SBjörn Töpel pivot = (b - a) / 2; 192475ccbef6SBjörn Töpel EMIT1(add_1mod(0x48, BPF_REG_3)); /* cmp rdx,func */ 192575ccbef6SBjörn Töpel if (!is_simm32(progs[a + pivot])) 192675ccbef6SBjörn Töpel return -1; 192775ccbef6SBjörn Töpel EMIT2_off32(0x81, add_1reg(0xF8, BPF_REG_3), progs[a + pivot]); 192875ccbef6SBjörn Töpel 192975ccbef6SBjörn Töpel if (pivot > 2) { /* jg upper_part */ 193075ccbef6SBjörn Töpel /* Require near jump. */ 193175ccbef6SBjörn Töpel jg_bytes = 4; 193275ccbef6SBjörn Töpel EMIT2_off32(0x0F, X86_JG + 0x10, 0); 193375ccbef6SBjörn Töpel } else { 193475ccbef6SBjörn Töpel EMIT2(X86_JG, 0); 193575ccbef6SBjörn Töpel } 193675ccbef6SBjörn Töpel jg_reloc = prog; 193775ccbef6SBjörn Töpel 193875ccbef6SBjörn Töpel err = emit_bpf_dispatcher(&prog, a, a + pivot, /* emit lower_part */ 193975ccbef6SBjörn Töpel progs); 194075ccbef6SBjörn Töpel if (err) 194175ccbef6SBjörn Töpel return err; 194275ccbef6SBjörn Töpel 1943116eb788SBjörn Töpel /* From Intel 64 and IA-32 Architectures Optimization 1944116eb788SBjörn Töpel * Reference Manual, 3.4.1.4 Code Alignment, Assembly/Compiler 1945116eb788SBjörn Töpel * Coding Rule 11: All branch targets should be 16-byte 1946116eb788SBjörn Töpel * aligned. 1947116eb788SBjörn Töpel */ 19487e639208SKP Singh emit_align(&prog, 16); 194975ccbef6SBjörn Töpel jg_offset = prog - jg_reloc; 195075ccbef6SBjörn Töpel emit_code(jg_reloc - jg_bytes, jg_offset, jg_bytes); 195175ccbef6SBjörn Töpel 195275ccbef6SBjörn Töpel err = emit_bpf_dispatcher(&prog, a + pivot + 1, /* emit upper_part */ 195375ccbef6SBjörn Töpel b, progs); 195475ccbef6SBjörn Töpel if (err) 195575ccbef6SBjörn Töpel return err; 195675ccbef6SBjörn Töpel 195775ccbef6SBjörn Töpel *pprog = prog; 195875ccbef6SBjörn Töpel return 0; 195975ccbef6SBjörn Töpel } 196075ccbef6SBjörn Töpel 196175ccbef6SBjörn Töpel static int cmp_ips(const void *a, const void *b) 196275ccbef6SBjörn Töpel { 196375ccbef6SBjörn Töpel const s64 *ipa = a; 196475ccbef6SBjörn Töpel const s64 *ipb = b; 196575ccbef6SBjörn Töpel 196675ccbef6SBjörn Töpel if (*ipa > *ipb) 196775ccbef6SBjörn Töpel return 1; 196875ccbef6SBjörn Töpel if (*ipa < *ipb) 196975ccbef6SBjörn Töpel return -1; 197075ccbef6SBjörn Töpel return 0; 197175ccbef6SBjörn Töpel } 197275ccbef6SBjörn Töpel 197375ccbef6SBjörn Töpel int arch_prepare_bpf_dispatcher(void *image, s64 *funcs, int num_funcs) 197475ccbef6SBjörn Töpel { 197575ccbef6SBjörn Töpel u8 *prog = image; 197675ccbef6SBjörn Töpel 197775ccbef6SBjörn Töpel sort(funcs, num_funcs, sizeof(funcs[0]), cmp_ips, NULL); 197875ccbef6SBjörn Töpel return emit_bpf_dispatcher(&prog, 0, num_funcs - 1, funcs); 197975ccbef6SBjörn Töpel } 198075ccbef6SBjörn Töpel 19811c2a088aSAlexei Starovoitov struct x64_jit_data { 19821c2a088aSAlexei Starovoitov struct bpf_binary_header *header; 19831c2a088aSAlexei Starovoitov int *addrs; 19841c2a088aSAlexei Starovoitov u8 *image; 19851c2a088aSAlexei Starovoitov int proglen; 19861c2a088aSAlexei Starovoitov struct jit_context ctx; 19871c2a088aSAlexei Starovoitov }; 19881c2a088aSAlexei Starovoitov 1989d1c55ab5SDaniel Borkmann struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) 199062258278SAlexei Starovoitov { 1991f3c2af7bSAlexei Starovoitov struct bpf_binary_header *header = NULL; 1992959a7579SDaniel Borkmann struct bpf_prog *tmp, *orig_prog = prog; 19931c2a088aSAlexei Starovoitov struct x64_jit_data *jit_data; 1994f3c2af7bSAlexei Starovoitov int proglen, oldproglen = 0; 1995f3c2af7bSAlexei Starovoitov struct jit_context ctx = {}; 1996959a7579SDaniel Borkmann bool tmp_blinded = false; 19971c2a088aSAlexei Starovoitov bool extra_pass = false; 1998f3c2af7bSAlexei Starovoitov u8 *image = NULL; 1999f3c2af7bSAlexei Starovoitov int *addrs; 2000f3c2af7bSAlexei Starovoitov int pass; 2001f3c2af7bSAlexei Starovoitov int i; 2002f3c2af7bSAlexei Starovoitov 200360b58afcSAlexei Starovoitov if (!prog->jit_requested) 2004959a7579SDaniel Borkmann return orig_prog; 2005959a7579SDaniel Borkmann 2006959a7579SDaniel Borkmann tmp = bpf_jit_blind_constants(prog); 2007a2c7a983SIngo Molnar /* 2008a2c7a983SIngo Molnar * If blinding was requested and we failed during blinding, 2009959a7579SDaniel Borkmann * we must fall back to the interpreter. 2010959a7579SDaniel Borkmann */ 2011959a7579SDaniel Borkmann if (IS_ERR(tmp)) 2012959a7579SDaniel Borkmann return orig_prog; 2013959a7579SDaniel Borkmann if (tmp != prog) { 2014959a7579SDaniel Borkmann tmp_blinded = true; 2015959a7579SDaniel Borkmann prog = tmp; 2016959a7579SDaniel Borkmann } 2017f3c2af7bSAlexei Starovoitov 20181c2a088aSAlexei Starovoitov jit_data = prog->aux->jit_data; 20191c2a088aSAlexei Starovoitov if (!jit_data) { 20201c2a088aSAlexei Starovoitov jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); 20211c2a088aSAlexei Starovoitov if (!jit_data) { 20221c2a088aSAlexei Starovoitov prog = orig_prog; 20231c2a088aSAlexei Starovoitov goto out; 20241c2a088aSAlexei Starovoitov } 20251c2a088aSAlexei Starovoitov prog->aux->jit_data = jit_data; 20261c2a088aSAlexei Starovoitov } 20271c2a088aSAlexei Starovoitov addrs = jit_data->addrs; 20281c2a088aSAlexei Starovoitov if (addrs) { 20291c2a088aSAlexei Starovoitov ctx = jit_data->ctx; 20301c2a088aSAlexei Starovoitov oldproglen = jit_data->proglen; 20311c2a088aSAlexei Starovoitov image = jit_data->image; 20321c2a088aSAlexei Starovoitov header = jit_data->header; 20331c2a088aSAlexei Starovoitov extra_pass = true; 20341c2a088aSAlexei Starovoitov goto skip_init_addrs; 20351c2a088aSAlexei Starovoitov } 20367c2e988fSAlexei Starovoitov addrs = kmalloc_array(prog->len + 1, sizeof(*addrs), GFP_KERNEL); 2037959a7579SDaniel Borkmann if (!addrs) { 2038959a7579SDaniel Borkmann prog = orig_prog; 20391c2a088aSAlexei Starovoitov goto out_addrs; 2040959a7579SDaniel Borkmann } 2041f3c2af7bSAlexei Starovoitov 2042a2c7a983SIngo Molnar /* 2043a2c7a983SIngo Molnar * Before first pass, make a rough estimation of addrs[] 2044a2c7a983SIngo Molnar * each BPF instruction is translated to less than 64 bytes 2045f3c2af7bSAlexei Starovoitov */ 20467c2e988fSAlexei Starovoitov for (proglen = 0, i = 0; i <= prog->len; i++) { 2047f3c2af7bSAlexei Starovoitov proglen += 64; 2048f3c2af7bSAlexei Starovoitov addrs[i] = proglen; 2049f3c2af7bSAlexei Starovoitov } 2050f3c2af7bSAlexei Starovoitov ctx.cleanup_addr = proglen; 20511c2a088aSAlexei Starovoitov skip_init_addrs: 2052f3c2af7bSAlexei Starovoitov 2053a2c7a983SIngo Molnar /* 2054a2c7a983SIngo Molnar * JITed image shrinks with every pass and the loop iterates 2055a2c7a983SIngo Molnar * until the image stops shrinking. Very large BPF programs 20563f7352bfSAlexei Starovoitov * may converge on the last pass. In such case do one more 2057a2c7a983SIngo Molnar * pass to emit the final image. 20583f7352bfSAlexei Starovoitov */ 20596007b080SDaniel Borkmann for (pass = 0; pass < 20 || image; pass++) { 2060f3c2af7bSAlexei Starovoitov proglen = do_jit(prog, addrs, image, oldproglen, &ctx); 2061f3c2af7bSAlexei Starovoitov if (proglen <= 0) { 20623aab8884SDaniel Borkmann out_image: 2063f3c2af7bSAlexei Starovoitov image = NULL; 2064f3c2af7bSAlexei Starovoitov if (header) 2065738cbe72SDaniel Borkmann bpf_jit_binary_free(header); 2066959a7579SDaniel Borkmann prog = orig_prog; 2067959a7579SDaniel Borkmann goto out_addrs; 2068f3c2af7bSAlexei Starovoitov } 20690a14842fSEric Dumazet if (image) { 2070e0ee9c12SAlexei Starovoitov if (proglen != oldproglen) { 2071f3c2af7bSAlexei Starovoitov pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", 2072f3c2af7bSAlexei Starovoitov proglen, oldproglen); 20733aab8884SDaniel Borkmann goto out_image; 2074e0ee9c12SAlexei Starovoitov } 20750a14842fSEric Dumazet break; 20760a14842fSEric Dumazet } 20770a14842fSEric Dumazet if (proglen == oldproglen) { 20783dec541bSAlexei Starovoitov /* 20793dec541bSAlexei Starovoitov * The number of entries in extable is the number of BPF_LDX 20803dec541bSAlexei Starovoitov * insns that access kernel memory via "pointer to BTF type". 20813dec541bSAlexei Starovoitov * The verifier changed their opcode from LDX|MEM|size 20823dec541bSAlexei Starovoitov * to LDX|PROBE_MEM|size to make JITing easier. 20833dec541bSAlexei Starovoitov */ 20843dec541bSAlexei Starovoitov u32 align = __alignof__(struct exception_table_entry); 20853dec541bSAlexei Starovoitov u32 extable_size = prog->aux->num_exentries * 20863dec541bSAlexei Starovoitov sizeof(struct exception_table_entry); 20873dec541bSAlexei Starovoitov 20883dec541bSAlexei Starovoitov /* allocate module memory for x86 insns and extable */ 20893dec541bSAlexei Starovoitov header = bpf_jit_binary_alloc(roundup(proglen, align) + extable_size, 20903dec541bSAlexei Starovoitov &image, align, jit_fill_hole); 2091959a7579SDaniel Borkmann if (!header) { 2092959a7579SDaniel Borkmann prog = orig_prog; 2093959a7579SDaniel Borkmann goto out_addrs; 2094959a7579SDaniel Borkmann } 20953dec541bSAlexei Starovoitov prog->aux->extable = (void *) image + roundup(proglen, align); 20960a14842fSEric Dumazet } 20970a14842fSEric Dumazet oldproglen = proglen; 20986007b080SDaniel Borkmann cond_resched(); 20990a14842fSEric Dumazet } 210079617801SDaniel Borkmann 21010a14842fSEric Dumazet if (bpf_jit_enable > 1) 2102485d6511SDaniel Borkmann bpf_jit_dump(prog->len, proglen, pass + 1, image); 21030a14842fSEric Dumazet 21040a14842fSEric Dumazet if (image) { 21051c2a088aSAlexei Starovoitov if (!prog->is_func || extra_pass) { 2106428d5df1SDaniel Borkmann bpf_tail_call_direct_fixup(prog); 21079d876e79SDaniel Borkmann bpf_jit_binary_lock_ro(header); 21081c2a088aSAlexei Starovoitov } else { 21091c2a088aSAlexei Starovoitov jit_data->addrs = addrs; 21101c2a088aSAlexei Starovoitov jit_data->ctx = ctx; 21111c2a088aSAlexei Starovoitov jit_data->proglen = proglen; 21121c2a088aSAlexei Starovoitov jit_data->image = image; 21131c2a088aSAlexei Starovoitov jit_data->header = header; 21141c2a088aSAlexei Starovoitov } 2115f3c2af7bSAlexei Starovoitov prog->bpf_func = (void *)image; 2116a91263d5SDaniel Borkmann prog->jited = 1; 2117783d28ddSMartin KaFai Lau prog->jited_len = proglen; 21189d5ecb09SDaniel Borkmann } else { 21199d5ecb09SDaniel Borkmann prog = orig_prog; 21200a14842fSEric Dumazet } 2121959a7579SDaniel Borkmann 212239f56ca9SDaniel Borkmann if (!image || !prog->is_func || extra_pass) { 2123c454a46bSMartin KaFai Lau if (image) 21247c2e988fSAlexei Starovoitov bpf_prog_fill_jited_linfo(prog, addrs + 1); 2125959a7579SDaniel Borkmann out_addrs: 21260a14842fSEric Dumazet kfree(addrs); 21271c2a088aSAlexei Starovoitov kfree(jit_data); 21281c2a088aSAlexei Starovoitov prog->aux->jit_data = NULL; 21291c2a088aSAlexei Starovoitov } 2130959a7579SDaniel Borkmann out: 2131959a7579SDaniel Borkmann if (tmp_blinded) 2132959a7579SDaniel Borkmann bpf_jit_prog_release_other(prog, prog == orig_prog ? 2133959a7579SDaniel Borkmann tmp : orig_prog); 2134d1c55ab5SDaniel Borkmann return prog; 21350a14842fSEric Dumazet } 2136