diff options
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/Kconfig | 2 | ||||
-rw-r--r-- | arch/x86/include/asm/nospec-branch.h | 41 | ||||
-rw-r--r-- | arch/x86/net/Makefile | 7 | ||||
-rw-r--r-- | arch/x86/net/bpf_jit.S | 154 | ||||
-rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 343 | ||||
-rw-r--r-- | arch/x86/net/bpf_jit_comp32.c | 2419 |
6 files changed, 2577 insertions, 389 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index c07f492b871a..d51a71dcbac2 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -138,7 +138,7 @@ config X86 select HAVE_DMA_CONTIGUOUS select HAVE_DYNAMIC_FTRACE select HAVE_DYNAMIC_FTRACE_WITH_REGS - select HAVE_EBPF_JIT if X86_64 + select HAVE_EBPF_JIT select HAVE_EFFICIENT_UNALIGNED_ACCESS select HAVE_EXIT_THREAD select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index 8b38df98548e..f6f6c63da62f 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -308,16 +308,20 @@ do { \ * lfence * jmp spec_trap * do_rop: - * mov %rax,(%rsp) + * mov %rax,(%rsp) for x86_64 + * mov %edx,(%esp) for x86_32 * retq * * Without retpolines configured: * - * jmp *%rax + * jmp *%rax for x86_64 + * jmp *%edx for x86_32 */ #ifdef CONFIG_RETPOLINE -# define RETPOLINE_RAX_BPF_JIT_SIZE 17 -# define RETPOLINE_RAX_BPF_JIT() \ +# ifdef CONFIG_X86_64 +# define RETPOLINE_RAX_BPF_JIT_SIZE 17 +# define RETPOLINE_RAX_BPF_JIT() \ +do { \ EMIT1_off32(0xE8, 7); /* callq do_rop */ \ /* spec_trap: */ \ EMIT2(0xF3, 0x90); /* pause */ \ @@ -325,11 +329,30 @@ do { \ EMIT2(0xEB, 0xF9); /* jmp spec_trap */ \ /* do_rop: */ \ EMIT4(0x48, 0x89, 0x04, 0x24); /* mov %rax,(%rsp) */ \ - EMIT1(0xC3); /* retq */ -#else -# define RETPOLINE_RAX_BPF_JIT_SIZE 2 -# define RETPOLINE_RAX_BPF_JIT() \ - EMIT2(0xFF, 0xE0); /* jmp *%rax */ + EMIT1(0xC3); /* retq */ \ +} while (0) +# else /* !CONFIG_X86_64 */ +# define RETPOLINE_EDX_BPF_JIT() \ +do { \ + EMIT1_off32(0xE8, 7); /* call do_rop */ \ + /* spec_trap: */ \ + EMIT2(0xF3, 0x90); /* pause */ \ + EMIT3(0x0F, 0xAE, 0xE8); /* lfence */ \ + EMIT2(0xEB, 0xF9); /* jmp spec_trap */ \ + /* do_rop: */ \ + EMIT3(0x89, 0x14, 0x24); /* mov %edx,(%esp) */ \ + EMIT1(0xC3); /* ret */ \ +} while (0) +# endif +#else /* !CONFIG_RETPOLINE */ +# ifdef CONFIG_X86_64 +# define RETPOLINE_RAX_BPF_JIT_SIZE 2 +# define RETPOLINE_RAX_BPF_JIT() \ + EMIT2(0xFF, 0xE0); /* jmp *%rax */ +# else /* !CONFIG_X86_64 */ +# define RETPOLINE_EDX_BPF_JIT() \ + EMIT2(0xFF, 0xE2) /* jmp *%edx */ +# endif #endif #endif /* _ASM_X86_NOSPEC_BRANCH_H_ */ diff --git a/arch/x86/net/Makefile b/arch/x86/net/Makefile index fefb4b619598..59e123da580c 100644 --- a/arch/x86/net/Makefile +++ b/arch/x86/net/Makefile @@ -1,6 +1,9 @@ # # Arch-specific network modules # -OBJECT_FILES_NON_STANDARD_bpf_jit.o += y -obj-$(CONFIG_BPF_JIT) += bpf_jit.o bpf_jit_comp.o +ifeq ($(CONFIG_X86_32),y) + obj-$(CONFIG_BPF_JIT) += bpf_jit_comp32.o +else + obj-$(CONFIG_BPF_JIT) += bpf_jit_comp.o +endif diff --git a/arch/x86/net/bpf_jit.S b/arch/x86/net/bpf_jit.S deleted file mode 100644 index b33093f84528..000000000000 --- a/arch/x86/net/bpf_jit.S +++ /dev/null @@ -1,154 +0,0 @@ -/* bpf_jit.S : BPF JIT helper functions - * - * Copyright (C) 2011 Eric Dumazet (eric.dumazet@gmail.com) - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; version 2 - * of the License. - */ -#include <linux/linkage.h> -#include <asm/frame.h> - -/* - * Calling convention : - * rbx : skb pointer (callee saved) - * esi : offset of byte(s) to fetch in skb (can be scratched) - * r10 : copy of skb->data - * r9d : hlen = skb->len - skb->data_len - */ -#define SKBDATA %r10 -#define SKF_MAX_NEG_OFF $(-0x200000) /* SKF_LL_OFF from filter.h */ - -#define FUNC(name) \ - .globl name; \ - .type name, @function; \ - name: - -FUNC(sk_load_word) - test %esi,%esi - js bpf_slow_path_word_neg - -FUNC(sk_load_word_positive_offset) - mov %r9d,%eax # hlen - sub %esi,%eax # hlen - offset - cmp $3,%eax - jle bpf_slow_path_word - mov (SKBDATA,%rsi),%eax - bswap %eax /* ntohl() */ - ret - -FUNC(sk_load_half) - test %esi,%esi - js bpf_slow_path_half_neg - -FUNC(sk_load_half_positive_offset) - mov %r9d,%eax - sub %esi,%eax # hlen - offset - cmp $1,%eax - jle bpf_slow_path_half - movzwl (SKBDATA,%rsi),%eax - rol $8,%ax # ntohs() - ret - -FUNC(sk_load_byte) - test %esi,%esi - js bpf_slow_path_byte_neg - -FUNC(sk_load_byte_positive_offset) - cmp %esi,%r9d /* if (offset >= hlen) goto bpf_slow_path_byte */ - jle bpf_slow_path_byte - movzbl (SKBDATA,%rsi),%eax - ret - -/* rsi contains offset and can be scratched */ -#define bpf_slow_path_common(LEN) \ - lea 32(%rbp), %rdx;\ - FRAME_BEGIN; \ - mov %rbx, %rdi; /* arg1 == skb */ \ - push %r9; \ - push SKBDATA; \ -/* rsi already has offset */ \ - mov $LEN,%ecx; /* len */ \ - call skb_copy_bits; \ - test %eax,%eax; \ - pop SKBDATA; \ - pop %r9; \ - FRAME_END - - -bpf_slow_path_word: - bpf_slow_path_common(4) - js bpf_error - mov 32(%rbp),%eax - bswap %eax - ret - -bpf_slow_path_half: - bpf_slow_path_common(2) - js bpf_error - mov 32(%rbp),%ax - rol $8,%ax - movzwl %ax,%eax - ret - -bpf_slow_path_byte: - bpf_slow_path_common(1) - js bpf_error - movzbl 32(%rbp),%eax - ret - -#define sk_negative_common(SIZE) \ - FRAME_BEGIN; \ - mov %rbx, %rdi; /* arg1 == skb */ \ - push %r9; \ - push SKBDATA; \ -/* rsi already has offset */ \ - mov $SIZE,%edx; /* size */ \ - call bpf_internal_load_pointer_neg_helper; \ - test %rax,%rax; \ - pop SKBDATA; \ - pop %r9; \ - FRAME_END; \ - jz bpf_error - -bpf_slow_path_word_neg: - cmp SKF_MAX_NEG_OFF, %esi /* test range */ - jl bpf_error /* offset lower -> error */ - -FUNC(sk_load_word_negative_offset) - sk_negative_common(4) - mov (%rax), %eax - bswap %eax - ret - -bpf_slow_path_half_neg: - cmp SKF_MAX_NEG_OFF, %esi - jl bpf_error - -FUNC(sk_load_half_negative_offset) - sk_negative_common(2) - mov (%rax),%ax - rol $8,%ax - movzwl %ax,%eax - ret - -bpf_slow_path_byte_neg: - cmp SKF_MAX_NEG_OFF, %esi - jl bpf_error - -FUNC(sk_load_byte_negative_offset) - sk_negative_common(1) - movzbl (%rax), %eax - ret - -bpf_error: -# force a return 0 from jit handler - xor %eax,%eax - mov (%rbp),%rbx - mov 8(%rbp),%r13 - mov 16(%rbp),%r14 - mov 24(%rbp),%r15 - add $40, %rbp - leaveq - ret diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 263c8453815e..8fca446aaef6 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1,4 +1,5 @@ -/* bpf_jit_comp.c : BPF JIT compiler +/* + * bpf_jit_comp.c: BPF JIT compiler * * Copyright (C) 2011-2013 Eric Dumazet (eric.dumazet@gmail.com) * Internal BPF Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com @@ -16,15 +17,6 @@ #include <asm/set_memory.h> #include <asm/nospec-branch.h> -/* - * assembly code in arch/x86/net/bpf_jit.S - */ -extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; -extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[]; -extern u8 sk_load_byte_positive_offset[]; -extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[]; -extern u8 sk_load_byte_negative_offset[]; - static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) { if (len == 1) @@ -45,14 +37,15 @@ static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) #define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2) #define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3) #define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4) + #define EMIT1_off32(b1, off) \ - do {EMIT1(b1); EMIT(off, 4); } while (0) + do { EMIT1(b1); EMIT(off, 4); } while (0) #define EMIT2_off32(b1, b2, off) \ - do {EMIT2(b1, b2); EMIT(off, 4); } while (0) + do { EMIT2(b1, b2); EMIT(off, 4); } while (0) #define EMIT3_off32(b1, b2, b3, off) \ - do {EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) + do { EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) #define EMIT4_off32(b1, b2, b3, b4, off) \ - do {EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) + do { EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) static bool is_imm8(int value) { @@ -70,9 +63,10 @@ static bool is_uimm32(u64 value) } /* mov dst, src */ -#define EMIT_mov(DST, SRC) \ - do {if (DST != SRC) \ - EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ +#define EMIT_mov(DST, SRC) \ + do { \ + if (DST != SRC) \ + EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ } while (0) static int bpf_size_to_x86_bytes(int bpf_size) @@ -89,7 +83,8 @@ static int bpf_size_to_x86_bytes(int bpf_size) return 0; } -/* list of x86 cond jumps opcodes (. + s8) +/* + * List of x86 cond jumps opcodes (. + s8) * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32) */ #define X86_JB 0x72 @@ -103,38 +98,37 @@ static int bpf_size_to_x86_bytes(int bpf_size) #define X86_JLE 0x7E #define X86_JG 0x7F -#define CHOOSE_LOAD_FUNC(K, func) \ - ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) - -/* pick a register outside of BPF range for JIT internal work */ +/* Pick a register outside of BPF range for JIT internal work */ #define AUX_REG (MAX_BPF_JIT_REG + 1) -/* The following table maps BPF registers to x64 registers. +/* + * The following table maps BPF registers to x86-64 registers. * - * x64 register r12 is unused, since if used as base address + * x86-64 register R12 is unused, since if used as base address * register in load/store instructions, it always needs an * extra byte of encoding and is callee saved. * - * r9 caches skb->len - skb->data_len - * r10 caches skb->data, and used for blinding (if enabled) + * Also x86-64 register R9 is unused. x86-64 register R10 is + * used for blinding (if enabled). */ static const int reg2hex[] = { - [BPF_REG_0] = 0, /* rax */ - [BPF_REG_1] = 7, /* rdi */ - [BPF_REG_2] = 6, /* rsi */ - [BPF_REG_3] = 2, /* rdx */ - [BPF_REG_4] = 1, /* rcx */ - [BPF_REG_5] = 0, /* r8 */ - [BPF_REG_6] = 3, /* rbx callee saved */ - [BPF_REG_7] = 5, /* r13 callee saved */ - [BPF_REG_8] = 6, /* r14 callee saved */ - [BPF_REG_9] = 7, /* r15 callee saved */ - [BPF_REG_FP] = 5, /* rbp readonly */ - [BPF_REG_AX] = 2, /* r10 temp register */ - [AUX_REG] = 3, /* r11 temp register */ + [BPF_REG_0] = 0, /* RAX */ + [BPF_REG_1] = 7, /* RDI */ + [BPF_REG_2] = 6, /* RSI */ + [BPF_REG_3] = 2, /* RDX */ + [BPF_REG_4] = 1, /* RCX */ + [BPF_REG_5] = 0, /* R8 */ + [BPF_REG_6] = 3, /* RBX callee saved */ + [BPF_REG_7] = 5, /* R13 callee saved */ + [BPF_REG_8] = 6, /* R14 callee saved */ + [BPF_REG_9] = 7, /* R15 callee saved */ + [BPF_REG_FP] = 5, /* RBP readonly */ + [BPF_REG_AX] = 2, /* R10 temp register */ + [AUX_REG] = 3, /* R11 temp register */ }; -/* is_ereg() == true if BPF register 'reg' maps to x64 r8..r15 +/* + * is_ereg() == true if BPF register 'reg' maps to x86-64 r8..r15 * which need extra byte of encoding. * rax,rcx,...,rbp have simpler encoding */ @@ -153,7 +147,7 @@ static bool is_axreg(u32 reg) return reg == BPF_REG_0; } -/* add modifiers if 'reg' maps to x64 registers r8..r15 */ +/* Add modifiers if 'reg' maps to x86-64 registers R8..R15 */ static u8 add_1mod(u8 byte, u32 reg) { if (is_ereg(reg)) @@ -170,13 +164,13 @@ static u8 add_2mod(u8 byte, u32 r1, u32 r2) return byte; } -/* encode 'dst_reg' register into x64 opcode 'byte' */ +/* Encode 'dst_reg' register into x86-64 opcode 'byte' */ static u8 add_1reg(u8 byte, u32 dst_reg) { return byte + reg2hex[dst_reg]; } -/* encode 'dst_reg' and 'src_reg' registers into x64 opcode 'byte' */ +/* Encode 'dst_reg' and 'src_reg' registers into x86-64 opcode 'byte' */ static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) { return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); @@ -184,27 +178,24 @@ static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) static void jit_fill_hole(void *area, unsigned int size) { - /* fill whole space with int3 instructions */ + /* Fill whole space with INT3 instructions */ memset(area, 0xcc, size); } struct jit_context { - int cleanup_addr; /* epilogue code offset */ - bool seen_ld_abs; - bool seen_ax_reg; + int cleanup_addr; /* Epilogue code offset */ }; -/* maximum number of bytes emitted while JITing one eBPF insn */ +/* Maximum number of bytes emitted while JITing one eBPF insn */ #define BPF_MAX_INSN_SIZE 128 #define BPF_INSN_SAFETY 64 -#define AUX_STACK_SPACE \ - (32 /* space for rbx, r13, r14, r15 */ + \ - 8 /* space for skb_copy_bits() buffer */) +#define AUX_STACK_SPACE 40 /* Space for RBX, R13, R14, R15, tailcnt */ -#define PROLOGUE_SIZE 37 +#define PROLOGUE_SIZE 37 -/* emit x64 prologue code for BPF program and check it's size. +/* + * Emit x86-64 prologue code for BPF program and check its size. * bpf_tail_call helper will skip it while jumping into another program */ static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf) @@ -212,8 +203,11 @@ static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf) u8 *prog = *pprog; int cnt = 0; - EMIT1(0x55); /* push rbp */ - EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */ + /* push rbp */ + EMIT1(0x55); + + /* mov rbp,rsp */ + EMIT3(0x48, 0x89, 0xE5); /* sub rsp, rounded_stack_depth + AUX_STACK_SPACE */ EMIT3_off32(0x48, 0x81, 0xEC, @@ -222,19 +216,8 @@ static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf) /* sub rbp, AUX_STACK_SPACE */ EMIT4(0x48, 0x83, 0xED, AUX_STACK_SPACE); - /* all classic BPF filters use R6(rbx) save it */ - /* mov qword ptr [rbp+0],rbx */ EMIT4(0x48, 0x89, 0x5D, 0); - - /* bpf_convert_filter() maps classic BPF register X to R7 and uses R8 - * as temporary, so all tcpdump filters need to spill/fill R7(r13) and - * R8(r14). R9(r15) spill could be made conditional, but there is only - * one 'bpf_error' return path out of helper functions inside bpf_jit.S - * The overhead of extra spill is negligible for any filter other - * than synthetic ones. Therefore not worth adding complexity. - */ - /* mov qword ptr [rbp+8],r13 */ EMIT4(0x4C, 0x89, 0x6D, 8); /* mov qword ptr [rbp+16],r14 */ @@ -243,9 +226,10 @@ static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf) EMIT4(0x4C, 0x89, 0x7D, 24); if (!ebpf_from_cbpf) { - /* Clear the tail call counter (tail_call_cnt): for eBPF tail + /* + * Clear the tail call counter (tail_call_cnt): for eBPF tail * calls we need to reset the counter to 0. It's done in two - * instructions, resetting rax register to 0, and moving it + * instructions, resetting RAX register to 0, and moving it * to the counter location. */ @@ -260,7 +244,9 @@ static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf) *pprog = prog; } -/* generate the following code: +/* + * Generate the following code: + * * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... * if (index >= array->map.max_entries) * goto out; @@ -278,23 +264,26 @@ static void emit_bpf_tail_call(u8 **pprog) int label1, label2, label3; int cnt = 0; - /* rdi - pointer to ctx + /* + * rdi - pointer to ctx * rsi - pointer to bpf_array * rdx - index in bpf_array */ - /* if (index >= array->map.max_entries) - * goto out; + /* + * if (index >= array->map.max_entries) + * goto out; */ EMIT2(0x89, 0xD2); /* mov edx, edx */ EMIT3(0x39, 0x56, /* cmp dword ptr [rsi + 16], edx */ offsetof(struct bpf_array, map.max_entries)); -#define OFFSET1 (41 + RETPOLINE_RAX_BPF_JIT_SIZE) /* number of bytes to jump */ +#define OFFSET1 (41 + RETPOLINE_RAX_BPF_JIT_SIZE) /* Number of bytes to jump */ EMIT2(X86_JBE, OFFSET1); /* jbe out */ label1 = cnt; - /* if (tail_call_cnt > MAX_TAIL_CALL_CNT) - * goto out; + /* + * if (tail_call_cnt > MAX_TAIL_CALL_CNT) + * goto out; */ EMIT2_off32(0x8B, 0x85, 36); /* mov eax, dword ptr [rbp + 36] */ EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ @@ -308,8 +297,9 @@ static void emit_bpf_tail_call(u8 **pprog) EMIT4_off32(0x48, 0x8B, 0x84, 0xD6, /* mov rax, [rsi + rdx * 8 + offsetof(...)] */ offsetof(struct bpf_array, ptrs)); - /* if (prog == NULL) - * goto out; + /* + * if (prog == NULL) + * goto out; */ EMIT3(0x48, 0x85, 0xC0); /* test rax,rax */ #define OFFSET3 (8 + RETPOLINE_RAX_BPF_JIT_SIZE) @@ -321,7 +311,8 @@ static void emit_bpf_tail_call(u8 **pprog) offsetof(struct bpf_prog, bpf_func)); EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */ - /* now we're ready to jump into next BPF program + /* + * Wow we're ready to jump into next BPF program * rdi == ctx (1st arg) * rax == prog->bpf_func + prologue_size */ @@ -334,26 +325,6 @@ static void emit_bpf_tail_call(u8 **pprog) *pprog = prog; } - -static void emit_load_skb_data_hlen(u8 **pprog) -{ - u8 *prog = *pprog; - int cnt = 0; - - /* r9d = skb->len - skb->data_len (headlen) - * r10 = skb->data - */ - /* mov %r9d, off32(%rdi) */ - EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len)); - - /* sub %r9d, off32(%rdi) */ - EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len)); - - /* mov %r10, off32(%rdi) */ - EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data)); - *pprog = prog; -} - static void emit_mov_imm32(u8 **pprog, bool sign_propagate, u32 dst_reg, const u32 imm32) { @@ -361,7 +332,8 @@ static void emit_mov_imm32(u8 **pprog, bool sign_propagate, u8 b1, b2, b3; int cnt = 0; - /* optimization: if imm32 is positive, use 'mov %eax, imm32' + /* + * Optimization: if imm32 is positive, use 'mov %eax, imm32' * (which zero-extends imm32) to save 2 bytes. */ if (sign_propagate && (s32)imm32 < 0) { @@ -373,7 +345,8 @@ static void emit_mov_imm32(u8 **pprog, bool sign_propagate, goto done; } - /* optimization: if imm32 is zero, use 'xor %eax, %eax' + /* + * Optimization: if imm32 is zero, use 'xor %eax, %eax' * to save 3 bytes. */ if (imm32 == 0) { @@ -400,7 +373,8 @@ static void emit_mov_imm64(u8 **pprog, u32 dst_reg, int cnt = 0; if (is_uimm32(((u64)imm32_hi << 32) | (u32)imm32_lo)) { - /* For emitting plain u32, where sign bit must not be + /* + * For emitting plain u32, where sign bit must not be * propagated LLVM tends to load imm64 over mov32 * directly, so save couple of bytes by just doing * 'mov %eax, imm32' instead. @@ -439,8 +413,6 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, { struct bpf_insn *insn = bpf_prog->insnsi; int insn_cnt = bpf_prog->len; - bool seen_ld_abs = ctx->seen_ld_abs | (oldproglen == 0); - bool seen_ax_reg = ctx->seen_ax_reg | (oldproglen == 0); bool seen_exit = false; u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; int i, cnt = 0; @@ -450,9 +422,6 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, emit_prologue(&prog, bpf_prog->aux->stack_depth, bpf_prog_was_classic(bpf_prog)); - if (seen_ld_abs) - emit_load_skb_data_hlen(&prog); - for (i = 0; i < insn_cnt; i++, insn++) { const s32 imm32 = insn->imm; u32 dst_reg = insn->dst_reg; @@ -460,13 +429,9 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 b2 = 0, b3 = 0; s64 jmp_offset; u8 jmp_cond; - bool reload_skb_data; int ilen; u8 *func; - if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX) - ctx->seen_ax_reg = seen_ax_reg = true; - switch (insn->code) { /* ALU */ case BPF_ALU | BPF_ADD | BPF_X: @@ -525,7 +490,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, else if (is_ereg(dst_reg)) EMIT1(add_1mod(0x40, dst_reg)); - /* b3 holds 'normal' opcode, b2 short form only valid + /* + * b3 holds 'normal' opcode, b2 short form only valid * in case dst is eax/rax. */ switch (BPF_OP(insn->code)) { @@ -593,7 +559,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, /* mov rax, dst_reg */ EMIT_mov(BPF_REG_0, dst_reg); - /* xor edx, edx + /* + * xor edx, edx * equivalent to 'xor rdx, rdx', but one byte less */ EMIT2(0x31, 0xd2); @@ -655,7 +622,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, } break; } - /* shifts */ + /* Shifts */ case BPF_ALU | BPF_LSH | BPF_K: case BPF_ALU | BPF_RSH | BPF_K: case BPF_ALU | BPF_ARSH | BPF_K: @@ -686,7 +653,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, case BPF_ALU64 | BPF_RSH | BPF_X: case BPF_ALU64 | BPF_ARSH | BPF_X: - /* check for bad case when dst_reg == rcx */ + /* Check for bad case when dst_reg == rcx */ if (dst_reg == BPF_REG_4) { /* mov r11, dst_reg */ EMIT_mov(AUX_REG, dst_reg); @@ -724,13 +691,13 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, case BPF_ALU | BPF_END | BPF_FROM_BE: switch (imm32) { case 16: - /* emit 'ror %ax, 8' to swap lower 2 bytes */ + /* Emit 'ror %ax, 8' to swap lower 2 bytes */ EMIT1(0x66); if (is_ereg(dst_reg)) EMIT1(0x41); EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); - /* emit 'movzwl eax, ax' */ + /* Emit 'movzwl eax, ax' */ if (is_ereg(dst_reg)) EMIT3(0x45, 0x0F, 0xB7); else @@ -738,7 +705,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); break; case 32: - /* emit 'bswap eax' to swap lower 4 bytes */ + /* Emit 'bswap eax' to swap lower 4 bytes */ if (is_ereg(dst_reg)) EMIT2(0x41, 0x0F); else @@ -746,7 +713,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, EMIT1(add_1reg(0xC8, dst_reg)); break; case 64: - /* emit 'bswap rax' to swap 8 bytes */ + /* Emit 'bswap rax' to swap 8 bytes */ EMIT3(add_1mod(0x48, dst_reg), 0x0F, add_1reg(0xC8, dst_reg)); break; @@ -756,7 +723,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, case BPF_ALU | BPF_END | BPF_FROM_LE: switch (imm32) { case 16: - /* emit 'movzwl eax, ax' to zero extend 16-bit + /* + * Emit 'movzwl eax, ax' to zero extend 16-bit * into 64 bit */ if (is_ereg(dst_reg)) @@ -766,7 +734,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); break; case 32: - /* emit 'mov eax, eax' to clear upper 32-bits */ + /* Emit 'mov eax, eax' to clear upper 32-bits */ if (is_ereg(dst_reg)) EMIT1(0x45); EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); @@ -809,9 +777,9 @@ st: if (is_imm8(insn->off)) /* STX: *(u8*)(dst_reg + off) = src_reg */ case BPF_STX | BPF_MEM | BPF_B: - /* emit 'mov byte ptr [rax + off], al' */ + /* Emit 'mov byte ptr [rax + off], al' */ if (is_ereg(dst_reg) || is_ereg(src_reg) || - /* have to add extra byte for x86 SIL, DIL regs */ + /* We have to add extra byte for x86 SIL, DIL regs */ src_reg == BPF_REG_1 || src_reg == BPF_REG_2) EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); else @@ -840,25 +808,26 @@ stx: if (is_imm8(insn->off)) /* LDX: dst_reg = *(u8*)(src_reg + off) */ case BPF_LDX | BPF_MEM | BPF_B: - /* emit 'movzx rax, byte ptr [rax + off]' */ + /* Emit 'movzx rax, byte ptr [rax + off]' */ EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); goto ldx; case BPF_LDX | BPF_MEM | BPF_H: - /* emit 'movzx rax, word ptr [rax + off]' */ + /* Emit 'movzx rax, word ptr [rax + off]' */ EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); goto ldx; case BPF_LDX | BPF_MEM | BPF_W: - /* emit 'mov eax, dword ptr [rax+0x14]' */ + /* Emit 'mov eax, dword ptr [rax+0x14]' */ if (is_ereg(dst_reg) || is_ereg(src_reg)) EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); else EMIT1(0x8B); goto ldx; case BPF_LDX | BPF_MEM | BPF_DW: - /* emit 'mov rax, qword ptr [rax+0x14]' */ + /* Emit 'mov rax, qword ptr [rax+0x14]' */ EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); -ldx: /* if insn->off == 0 we can save one extra byte, but - * special case of x86 r13 which always needs an offset +ldx: /* + * If insn->off == 0 we can save one extra byte, but + * special case of x86 R13 which always needs an offset * is not worth the hassle */ if (is_imm8(insn->off)) @@ -870,7 +839,7 @@ ldx: /* if insn->off == 0 we can save one extra byte, but /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ case BPF_STX | BPF_XADD | BPF_W: - /* emit 'lock add dword ptr [rax + off], eax' */ + /* Emit 'lock add dword ptr [rax + off], eax' */ if (is_ereg(dst_reg) || is_ereg(src_reg)) EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); else @@ -889,35 +858,12 @@ xadd: if (is_imm8(insn->off)) case BPF_JMP | BPF_CALL: func = (u8 *) __bpf_call_base + imm32; jmp_offset = func - (image + addrs[i]); - if (seen_ld_abs) { - reload_skb_data = bpf_helper_changes_pkt_data(func); - if (reload_skb_data) { - EMIT1(0x57); /* push %rdi */ - jmp_offset += 22; /* pop, mov, sub, mov */ - } else { - EMIT2(0x41, 0x52); /* push %r10 */ - EMIT2(0x41, 0x51); /* push %r9 */ - /* need to adjust jmp offset, since - * pop %r9, pop %r10 take 4 bytes after call insn - */ - jmp_offset += 4; - } - } if (!imm32 || !is_simm32(jmp_offset)) { - pr_err("unsupported bpf func %d addr %p image %p\n", + pr_err("unsupported BPF func %d addr %p image %p\n", imm32, func, image); return -EINVAL; } EMIT1_off32(0xE8, jmp_offset); - if (seen_ld_abs) { - if (reload_skb_data) { - EMIT1(0x5F); /* pop %rdi */ - emit_load_skb_data_hlen(&prog); - } else { - EMIT2(0x41, 0x59); /* pop %r9 */ - EMIT2(0x41, 0x5A); /* pop %r10 */ - } - } break; case BPF_JMP | BPF_TAIL_CALL: @@ -970,7 +916,7 @@ xadd: if (is_imm8(insn->off)) else EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); -emit_cond_jmp: /* convert BPF opcode to x86 */ +emit_cond_jmp: /* Convert BPF opcode to x86 */ switch (BPF_OP(insn->code)) { case BPF_JEQ: jmp_cond = X86_JE; @@ -996,22 +942,22 @@ emit_cond_jmp: /* convert BPF opcode to x86 */ jmp_cond = X86_JBE; break; case BPF_JSGT: - /* signed '>', GT in x86 */ + /* Signed '>', GT in x86 */ jmp_cond = X86_JG; break; case BPF_JSLT: - /* signed '<', LT in x86 */ + /* Signed '<', LT in x86 */ jmp_cond = X86_JL; break; case BPF_JSGE: - /* signed '>=', GE in x86 */ + /* Signed '>=', GE in x86 */ jmp_cond = X86_JGE; break; case BPF_JSLE: - /* signed '<=', LE in x86 */ + /* Signed '<=', LE in x86 */ jmp_cond = X86_JLE; break; - default: /* to silence gcc warning */ + default: /* to silence GCC warning */ return -EFAULT; } jmp_offset = addrs[i + insn->off] - addrs[i]; @@ -1039,7 +985,7 @@ emit_cond_jmp: /* convert BPF opcode to x86 */ jmp_offset = addrs[i + insn->off] - addrs[i]; if (!jmp_offset) - /* optimize out nop jumps */ + /* Optimize out nop jumps */ break; emit_jmp: if (is_imm8(jmp_offset)) { @@ -1052,66 +998,13 @@ emit_jmp: } break; - case BPF_LD | BPF_IND | BPF_W: - func = sk_load_word; - goto common_load; - case BPF_LD | BPF_ABS | BPF_W: - func = CHOOSE_LOAD_FUNC(imm32, sk_load_word); -common_load: - ctx->seen_ld_abs = seen_ld_abs = true; - jmp_offset = func - (image + addrs[i]); - if (!func || !is_simm32(jmp_offset)) { - pr_err("unsupported bpf func %d addr %p image %p\n", - imm32, func, image); - return -EINVAL; - } - if (BPF_MODE(insn->code) == BPF_ABS) { - /* mov %esi, imm32 */ - EMIT1_off32(0xBE, imm32); - } else { - /* mov %rsi, src_reg */ - EMIT_mov(BPF_REG_2, src_reg); - if (imm32) { - if (is_imm8(imm32)) - /* add %esi, imm8 */ - EMIT3(0x83, 0xC6, imm32); - else - /* add %esi, imm32 */ - EMIT2_off32(0x81, 0xC6, imm32); - } - } - /* skb pointer is in R6 (%rbx), it will be copied into - * %rdi if skb_copy_bits() call is necessary. - * sk_load_* helpers also use %r10 and %r9d. - * See bpf_jit.S - */ - if (seen_ax_reg) - /* r10 = skb->data, mov %r10, off32(%rbx) */ - EMIT3_off32(0x4c, 0x8b, 0x93, - offsetof(struct sk_buff, data)); - EMIT1_off32(0xE8, jmp_offset); /* call */ - break; - - case BPF_LD | BPF_IND | BPF_H: - func = sk_load_half; - goto common_load; - case BPF_LD | BPF_ABS | BPF_H: - func = CHOOSE_LOAD_FUNC(imm32, sk_load_half); - goto common_load; - case BPF_LD | BPF_IND | BPF_B: - func = sk_load_byte; - goto common_load; - case BPF_LD | BPF_ABS | BPF_B: - func = CHOOSE_LOAD_FUNC(imm32, sk_load_byte); - goto common_load; - case BPF_JMP | BPF_EXIT: if (seen_exit) { jmp_offset = ctx->cleanup_addr - addrs[i]; goto emit_jmp; } seen_exit = true; - /* update cleanup_addr */ + /* Update cleanup_addr */ ctx->cleanup_addr = proglen; /* mov rbx, qword ptr [rbp+0] */ EMIT4(0x48, 0x8B, 0x5D, 0); @@ -1129,10 +1022,11 @@ common_load: break; default: - /* By design x64 JIT should support all BPF instructions + /* + * By design x86-64 JIT should support all BPF instructions. * This error will be seen if new instruction was added - * to interpreter, but not to JIT - * or if there is junk in bpf_prog + * to the interpreter, but not to the JIT, or if there is + * junk in bpf_prog. */ pr_err("bpf_jit: unknown opcode %02x\n", insn->code); return -EINVAL; @@ -1184,7 +1078,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) return orig_prog; tmp = bpf_jit_blind_constants(prog); - /* If blinding was requested and we failed during blinding, + /* + * If blinding was requested and we failed during blinding, * we must fall back to the interpreter. */ if (IS_ERR(tmp)) @@ -1218,8 +1113,9 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) goto out_addrs; } - /* Before first pass, make a rough estimation of addrs[] - * each bpf instruction is translated to less than 64 bytes + /* + * Before first pass, make a rough estimation of addrs[] + * each BPF instruction is translated to less than 64 bytes */ for (proglen = 0, i = 0; i < prog->len; i++) { proglen += 64; @@ -1228,10 +1124,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) ctx.cleanup_addr = proglen; skip_init_addrs: - /* JITed image shrinks with every pass and the loop iterates - * until the image stops shrinking. Very large bpf programs + /* + * JITed image shrinks with every pass and the loop iterates + * until the image stops shrinking. Very large BPF programs * may converge on the last pass. In such case do one more - * pass to emit the final image + * pass to emit the final image. */ for (pass = 0; pass < 20 || image; pass++) { proglen = do_jit(prog, addrs, image, oldproglen, &ctx); diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c new file mode 100644 index 000000000000..0cc04e30adc1 --- /dev/null +++ b/arch/x86/net/bpf_jit_comp32.c @@ -0,0 +1,2419 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Just-In-Time compiler for eBPF filters on IA32 (32bit x86) + * + * Author: Wang YanQing (udknight@gmail.com) + * The code based on code and ideas from: + * Eric Dumazet (eric.dumazet@gmail.com) + * and from: + * Shubham Bansal <illusionist.neo@gmail.com> + */ + +#include <linux/netdevice.h> +#include <linux/filter.h> +#include <linux/if_vlan.h> +#include <asm/cacheflush.h> +#include <asm/set_memory.h> +#include <asm/nospec-branch.h> +#include <linux/bpf.h> + +/* + * eBPF prog stack layout: + * + * high + * original ESP => +-----+ + * | | callee saved registers + * +-----+ + * | ... | eBPF JIT scratch space + * BPF_FP,IA32_EBP => +-----+ + * | ... | eBPF prog stack + * +-----+ + * |RSVD | JIT scratchpad + * current ESP => +-----+ + * | | + * | ... | Function call stack + * | | + * +-----+ + * low + * + * The callee saved registers: + * + * high + * original ESP => +------------------+ \ + * | ebp | | + * current EBP => +------------------+ } callee saved registers + * | ebx,esi,edi | | + * +------------------+ / + * low + */ + +static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) +{ + if (len == 1) + *ptr = bytes; + else if (len == 2) + *(u16 *)ptr = bytes; + else { + *(u32 *)ptr = bytes; + barrier(); + } + return ptr + len; +} + +#define EMIT(bytes, len) \ + do { prog = emit_code(prog, bytes, len); cnt += len; } while (0) + +#define EMIT1(b1) EMIT(b1, 1) +#define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2) +#define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3) +#define EMIT4(b1, b2, b3, b4) \ + EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4) + +#define EMIT1_off32(b1, off) \ + do { EMIT1(b1); EMIT(off, 4); } while (0) +#define EMIT2_off32(b1, b2, off) \ + do { EMIT2(b1, b2); EMIT(off, 4); } while (0) +#define EMIT3_off32(b1, b2, b3, off) \ + do { EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) +#define EMIT4_off32(b1, b2, b3, b4, off) \ + do { EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) + +#define jmp_label(label, jmp_insn_len) (label - cnt - jmp_insn_len) + +static bool is_imm8(int value) +{ + return value <= 127 && value >= -128; +} + +static bool is_simm32(s64 value) +{ + return value == (s64) (s32) value; +} + +#define STACK_OFFSET(k) (k) +#define TCALL_CNT (MAX_BPF_JIT_REG + 0) /* Tail Call Count */ + +#define IA32_EAX (0x0) +#define IA32_EBX (0x3) +#define IA32_ECX (0x1) +#define IA32_EDX (0x2) +#define IA32_ESI (0x6) +#define IA32_EDI (0x7) +#define IA32_EBP (0x5) +#define IA32_ESP (0x4) + +/* + * List of x86 cond jumps opcodes (. + s8) + * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32) + */ +#define IA32_JB 0x72 +#define IA32_JAE 0x73 +#define IA32_JE 0x74 +#define IA32_JNE 0x75 +#define IA32_JBE 0x76 +#define IA32_JA 0x77 +#define IA32_JL 0x7C +#define IA32_JGE 0x7D +#define IA32_JLE 0x7E +#define IA32_JG 0x7F + +/* + * Map eBPF registers to IA32 32bit registers or stack scratch space. + * + * 1. All the registers, R0-R10, are mapped to scratch space on stack. + * 2. We need two 64 bit temp registers to do complex operations on eBPF + * registers. + * 3. For performance reason, the BPF_REG_AX for blinding constant, is + * mapped to real hardware register pair, IA32_ESI and IA32_EDI. + * + * As the eBPF registers are all 64 bit registers and IA32 has only 32 bit + * registers, we have to map each eBPF registers with two IA32 32 bit regs + * or scratch memory space and we have to build eBPF 64 bit register from those. + * + * We use IA32_EAX, IA32_EDX, IA32_ECX, IA32_EBX as temporary registers. + */ +static const u8 bpf2ia32[][2] = { + /* Return value from in-kernel function, and exit value from eBPF */ + [BPF_REG_0] = {STACK_OFFSET(0), STACK_OFFSET(4)}, + + /* The arguments from eBPF program to in-kernel function */ + /* Stored on stack scratch space */ + [BPF_REG_1] = {STACK_OFFSET(8), STACK_OFFSET(12)}, + [BPF_REG_2] = {STACK_OFFSET(16), STACK_OFFSET(20)}, + [BPF_REG_3] = {STACK_OFFSET(24), STACK_OFFSET(28)}, + [BPF_REG_4] = {STACK_OFFSET(32), STACK_OFFSET(36)}, + [BPF_REG_5] = {STACK_OFFSET(40), STACK_OFFSET(44)}, + + /* Callee saved registers that in-kernel function will preserve */ + /* Stored on stack scratch space */ + [BPF_REG_6] = {STACK_OFFSET(48), STACK_OFFSET(52)}, + [BPF_REG_7] = {STACK_OFFSET(56), STACK_OFFSET(60)}, + [BPF_REG_8] = {STACK_OFFSET(64), STACK_OFFSET(68)}, + [BPF_REG_9] = {STACK_OFFSET(72), STACK_OFFSET(76)}, + + /* Read only Frame Pointer to access Stack */ + [BPF_REG_FP] = {STACK_OFFSET(80), STACK_OFFSET(84)}, + + /* Temporary register for blinding constants. */ + [BPF_REG_AX] = {IA32_ESI, IA32_EDI}, + + /* Tail call count. Stored on stack scratch space. */ + [TCALL_CNT] = {STACK_OFFSET(88), STACK_OFFSET(92)}, +}; + +#define dst_lo dst[0] +#define dst_hi dst[1] +#define src_lo src[0] +#define src_hi src[1] + +#define STACK_ALIGNMENT 8 +/* + * Stack space for BPF_REG_1, BPF_REG_2, BPF_REG_3, BPF_REG_4, + * BPF_REG_5, BPF_REG_6, BPF_REG_7, BPF_REG_8, BPF_REG_9, + * BPF_REG_FP, BPF_REG_AX and Tail call counts. + */ +#define SCRATCH_SIZE 96 + +/* Total stack size used in JITed code */ +#define _STACK_SIZE (stack_depth + SCRATCH_SIZE) + +#define STACK_SIZE ALIGN(_STACK_SIZE, STACK_ALIGNMENT) + +/* Get the offset of eBPF REGISTERs stored on scratch space. */ +#define STACK_VAR(off) (off) + +/* Encode 'dst_reg' register into IA32 opcode 'byte' */ +static u8 add_1reg(u8 byte, u32 dst_reg) +{ + return byte + dst_reg; +} + +/* Encode 'dst_reg' and 'src_reg' registers into IA32 opcode 'byte' */ +static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) +{ + return byte + dst_reg + (src_reg << 3); +} + +static void jit_fill_hole(void *area, unsigned int size) +{ + /* Fill whole space with int3 instructions */ + memset(area, 0xcc, size); +} + +static inline void emit_ia32_mov_i(const u8 dst, const u32 val, bool dstk, + u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + + if (dstk) { + if (val == 0) { + /* xor eax,eax */ + EMIT2(0x33, add_2reg(0xC0, IA32_EAX, IA32_EAX)); + /* mov dword ptr [ebp+off],eax */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst)); + } else { + EMIT3_off32(0xC7, add_1reg(0x40, IA32_EBP), + STACK_VAR(dst), val); + } + } else { + if (val == 0) + EMIT2(0x33, add_2reg(0xC0, dst, dst)); + else + EMIT2_off32(0xC7, add_1reg(0xC0, dst), + val); + } + *pprog = prog; +} + +/* dst = imm (4 bytes)*/ +static inline void emit_ia32_mov_r(const u8 dst, const u8 src, bool dstk, + bool sstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + u8 sreg = sstk ? IA32_EAX : src; + + if (sstk) + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), STACK_VAR(src)); + if (dstk) + /* mov dword ptr [ebp+off],eax */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, sreg), STACK_VAR(dst)); + else + /* mov dst,sreg */ + EMIT2(0x89, add_2reg(0xC0, dst, sreg)); + + *pprog = prog; +} + +/* dst = src */ +static inline void emit_ia32_mov_r64(const bool is64, const u8 dst[], + const u8 src[], bool dstk, + bool sstk, u8 **pprog) +{ + emit_ia32_mov_r(dst_lo, src_lo, dstk, sstk, pprog); + if (is64) + /* complete 8 byte move */ + emit_ia32_mov_r(dst_hi, src_hi, dstk, sstk, pprog); + else + /* zero out high 4 bytes */ + emit_ia32_mov_i(dst_hi, 0, dstk, pprog); +} + +/* Sign extended move */ +static inline void emit_ia32_mov_i64(const bool is64, const u8 dst[], + const u32 val, bool dstk, u8 **pprog) +{ + u32 hi = 0; + + if (is64 && (val & (1<<31))) + hi = (u32)~0; + emit_ia32_mov_i(dst_lo, val, dstk, pprog); + emit_ia32_mov_i(dst_hi, hi, dstk, pprog); +} + +/* + * ALU operation (32 bit) + * dst = dst * src + */ +static inline void emit_ia32_mul_r(const u8 dst, const u8 src, bool dstk, + bool sstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + u8 sreg = sstk ? IA32_ECX : src; + + if (sstk) + /* mov ecx,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX), STACK_VAR(src)); + + if (dstk) + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), STACK_VAR(dst)); + else + /* mov eax,dst */ + EMIT2(0x8B, add_2reg(0xC0, dst, IA32_EAX)); + + + EMIT2(0xF7, add_1reg(0xE0, sreg)); + + if (dstk) + /* mov dword ptr [ebp+off],eax */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst)); + else + /* mov dst,eax */ + EMIT2(0x89, add_2reg(0xC0, dst, IA32_EAX)); + + *pprog = prog; +} + +static inline void emit_ia32_to_le_r64(const u8 dst[], s32 val, + bool dstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + u8 dreg_lo = dstk ? IA32_EAX : dst_lo; + u8 dreg_hi = dstk ? IA32_EDX : dst_hi; + + if (dstk && val != 64) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_hi)); + } + switch (val) { + case 16: + /* + * Emit 'movzwl eax,ax' to zero extend 16-bit + * into 64 bit + */ + EMIT2(0x0F, 0xB7); + EMIT1(add_2reg(0xC0, dreg_lo, dreg_lo)); + /* xor dreg_hi,dreg_hi */ + EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi)); + break; + case 32: + /* xor dreg_hi,dreg_hi */ + EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi)); + break; + case 64: + /* nop */ + break; + } + + if (dstk && val != 64) { + /* mov dword ptr [ebp+off],dreg_lo */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_lo), + STACK_VAR(dst_lo)); + /* mov dword ptr [ebp+off],dreg_hi */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_hi), + STACK_VAR(dst_hi)); + } + *pprog = prog; +} + +static inline void emit_ia32_to_be_r64(const u8 dst[], s32 val, + bool dstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + u8 dreg_lo = dstk ? IA32_EAX : dst_lo; + u8 dreg_hi = dstk ? IA32_EDX : dst_hi; + + if (dstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_hi)); + } + switch (val) { + case 16: + /* Emit 'ror %ax, 8' to swap lower 2 bytes */ + EMIT1(0x66); + EMIT3(0xC1, add_1reg(0xC8, dreg_lo), 8); + + EMIT2(0x0F, 0xB7); + EMIT1(add_2reg(0xC0, dreg_lo, dreg_lo)); + + /* xor dreg_hi,dreg_hi */ + EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi)); + break; + case 32: + /* Emit 'bswap eax' to swap lower 4 bytes */ + EMIT1(0x0F); + EMIT1(add_1reg(0xC8, dreg_lo)); + + /* xor dreg_hi,dreg_hi */ + EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi)); + break; + case 64: + /* Emit 'bswap eax' to swap lower 4 bytes */ + EMIT1(0x0F); + EMIT1(add_1reg(0xC8, dreg_lo)); + + /* Emit 'bswap edx' to swap lower 4 bytes */ + EMIT1(0x0F); + EMIT1(add_1reg(0xC8, dreg_hi)); + + /* mov ecx,dreg_hi */ + EMIT2(0x89, add_2reg(0xC0, IA32_ECX, dreg_hi)); + /* mov dreg_hi,dreg_lo */ + EMIT2(0x89, add_2reg(0xC0, dreg_hi, dreg_lo)); + /* mov dreg_lo,ecx */ + EMIT2(0x89, add_2reg(0xC0, dreg_lo, IA32_ECX)); + + break; + } + if (dstk) { + /* mov dword ptr [ebp+off],dreg_lo */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_lo), + STACK_VAR(dst_lo)); + /* mov dword ptr [ebp+off],dreg_hi */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_hi), + STACK_VAR(dst_hi)); + } + *pprog = prog; +} + +/* + * ALU operation (32 bit) + * dst = dst (div|mod) src + */ +static inline void emit_ia32_div_mod_r(const u8 op, const u8 dst, const u8 src, + bool dstk, bool sstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + + if (sstk) + /* mov ecx,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX), + STACK_VAR(src)); + else if (src != IA32_ECX) + /* mov ecx,src */ + EMIT2(0x8B, add_2reg(0xC0, src, IA32_ECX)); + + if (dstk) + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst)); + else + /* mov eax,dst */ + EMIT2(0x8B, add_2reg(0xC0, dst, IA32_EAX)); + + /* xor edx,edx */ + EMIT2(0x31, add_2reg(0xC0, IA32_EDX, IA32_EDX)); + /* div ecx */ + EMIT2(0xF7, add_1reg(0xF0, IA32_ECX)); + + if (op == BPF_MOD) { + if (dstk) + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst)); + else + EMIT2(0x89, add_2reg(0xC0, dst, IA32_EDX)); + } else { + if (dstk) + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst)); + else + EMIT2(0x89, add_2reg(0xC0, dst, IA32_EAX)); + } + *pprog = prog; +} + +/* + * ALU operation (32 bit) + * dst = dst (shift) src + */ +static inline void emit_ia32_shift_r(const u8 op, const u8 dst, const u8 src, + bool dstk, bool sstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + u8 dreg = dstk ? IA32_EAX : dst; + u8 b2; + + if (dstk) + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), STACK_VAR(dst)); + + if (sstk) + /* mov ecx,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX), STACK_VAR(src)); + else if (src != IA32_ECX) + /* mov ecx,src */ + EMIT2(0x8B, add_2reg(0xC0, src, IA32_ECX)); + + switch (op) { + case BPF_LSH: + b2 = 0xE0; break; + case BPF_RSH: + b2 = 0xE8; break; + case BPF_ARSH: + b2 = 0xF8; break; + default: + return; + } + EMIT2(0xD3, add_1reg(b2, dreg)); + + if (dstk) + /* mov dword ptr [ebp+off],dreg */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg), STACK_VAR(dst)); + *pprog = prog; +} + +/* + * ALU operation (32 bit) + * dst = dst (op) src + */ +static inline void emit_ia32_alu_r(const bool is64, const bool hi, const u8 op, + const u8 dst, const u8 src, bool dstk, + bool sstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + u8 sreg = sstk ? IA32_EAX : src; + u8 dreg = dstk ? IA32_EDX : dst; + + if (sstk) + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), STACK_VAR(src)); + + if (dstk) + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), STACK_VAR(dst)); + + switch (BPF_OP(op)) { + /* dst = dst + src */ + case BPF_ADD: + if (hi && is64) + EMIT2(0x11, add_2reg(0xC0, dreg, sreg)); + else + EMIT2(0x01, add_2reg(0xC0, dreg, sreg)); + break; + /* dst = dst - src */ + case BPF_SUB: + if (hi && is64) + EMIT2(0x19, add_2reg(0xC0, dreg, sreg)); + else + EMIT2(0x29, add_2reg(0xC0, dreg, sreg)); + break; + /* dst = dst | src */ + case BPF_OR: + EMIT2(0x09, add_2reg(0xC0, dreg, sreg)); + break; + /* dst = dst & src */ + case BPF_AND: + EMIT2(0x21, add_2reg(0xC0, dreg, sreg)); + break; + /* dst = dst ^ src */ + case BPF_XOR: + EMIT2(0x31, add_2reg(0xC0, dreg, sreg)); + break; + } + + if (dstk) + /* mov dword ptr [ebp+off],dreg */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg), + STACK_VAR(dst)); + *pprog = prog; +} + +/* ALU operation (64 bit) */ +static inline void emit_ia32_alu_r64(const bool is64, const u8 op, + const u8 dst[], const u8 src[], + bool dstk, bool sstk, + u8 **pprog) +{ + u8 *prog = *pprog; + + emit_ia32_alu_r(is64, false, op, dst_lo, src_lo, dstk, sstk, &prog); + if (is64) + emit_ia32_alu_r(is64, true, op, dst_hi, src_hi, dstk, sstk, + &prog); + else + emit_ia32_mov_i(dst_hi, 0, dstk, &prog); + *pprog = prog; +} + +/* + * ALU operation (32 bit) + * dst = dst (op) val + */ +static inline void emit_ia32_alu_i(const bool is64, const bool hi, const u8 op, + const u8 dst, const s32 val, bool dstk, + u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + u8 dreg = dstk ? IA32_EAX : dst; + u8 sreg = IA32_EDX; + + if (dstk) + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), STACK_VAR(dst)); + + if (!is_imm8(val)) + /* mov edx,imm32*/ + EMIT2_off32(0xC7, add_1reg(0xC0, IA32_EDX), val); + + switch (op) { + /* dst = dst + val */ + case BPF_ADD: + if (hi && is64) { + if (is_imm8(val)) + EMIT3(0x83, add_1reg(0xD0, dreg), val); + else + EMIT2(0x11, add_2reg(0xC0, dreg, sreg)); + } else { + if (is_imm8(val)) + EMIT3(0x83, add_1reg(0xC0, dreg), val); + else + EMIT2(0x01, add_2reg(0xC0, dreg, sreg)); + } + break; + /* dst = dst - val */ + case BPF_SUB: + if (hi && is64) { + if (is_imm8(val)) + EMIT3(0x83, add_1reg(0xD8, dreg), val); + else + EMIT2(0x19, add_2reg(0xC0, dreg, sreg)); + } else { + if (is_imm8(val)) + EMIT3(0x83, add_1reg(0xE8, dreg), val); + else + EMIT2(0x29, add_2reg(0xC0, dreg, sreg)); + } + break; + /* dst = dst | val */ + case BPF_OR: + if (is_imm8(val)) + EMIT3(0x83, add_1reg(0xC8, dreg), val); + else + EMIT2(0x09, add_2reg(0xC0, dreg, sreg)); + break; + /* dst = dst & val */ + case BPF_AND: + if (is_imm8(val)) + EMIT3(0x83, add_1reg(0xE0, dreg), val); + else + EMIT2(0x21, add_2reg(0xC0, dreg, sreg)); + break; + /* dst = dst ^ val */ + case BPF_XOR: + if (is_imm8(val)) + EMIT3(0x83, add_1reg(0xF0, dreg), val); + else + EMIT2(0x31, add_2reg(0xC0, dreg, sreg)); + break; + case BPF_NEG: + EMIT2(0xF7, add_1reg(0xD8, dreg)); + break; + } + + if (dstk) + /* mov dword ptr [ebp+off],dreg */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg), + STACK_VAR(dst)); + *pprog = prog; +} + +/* ALU operation (64 bit) */ +static inline void emit_ia32_alu_i64(const bool is64, const u8 op, + const u8 dst[], const u32 val, + bool dstk, u8 **pprog) +{ + u8 *prog = *pprog; + u32 hi = 0; + + if (is64 && (val & (1<<31))) + hi = (u32)~0; + + emit_ia32_alu_i(is64, false, op, dst_lo, val, dstk, &prog); + if (is64) + emit_ia32_alu_i(is64, true, op, dst_hi, hi, dstk, &prog); + else + emit_ia32_mov_i(dst_hi, 0, dstk, &prog); + + *pprog = prog; +} + +/* dst = ~dst (64 bit) */ +static inline void emit_ia32_neg64(const u8 dst[], bool dstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + u8 dreg_lo = dstk ? IA32_EAX : dst_lo; + u8 dreg_hi = dstk ? IA32_EDX : dst_hi; + + if (dstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_hi)); + } + + /* xor ecx,ecx */ + EMIT2(0x31, add_2reg(0xC0, IA32_ECX, IA32_ECX)); + /* sub dreg_lo,ecx */ + EMIT2(0x2B, add_2reg(0xC0, dreg_lo, IA32_ECX)); + /* mov dreg_lo,ecx */ + EMIT2(0x89, add_2reg(0xC0, dreg_lo, IA32_ECX)); + + /* xor ecx,ecx */ + EMIT2(0x31, add_2reg(0xC0, IA32_ECX, IA32_ECX)); + /* sbb dreg_hi,ecx */ + EMIT2(0x19, add_2reg(0xC0, dreg_hi, IA32_ECX)); + /* mov dreg_hi,ecx */ + EMIT2(0x89, add_2reg(0xC0, dreg_hi, IA32_ECX)); + + if (dstk) { + /* mov dword ptr [ebp+off],dreg_lo */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_lo), + STACK_VAR(dst_lo)); + /* mov dword ptr [ebp+off],dreg_hi */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_hi), + STACK_VAR(dst_hi)); + } + *pprog = prog; +} + +/* dst = dst << src */ +static inline void emit_ia32_lsh_r64(const u8 dst[], const u8 src[], + bool dstk, bool sstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + static int jmp_label1 = -1; + static int jmp_label2 = -1; + static int jmp_label3 = -1; + u8 dreg_lo = dstk ? IA32_EAX : dst_lo; + u8 dreg_hi = dstk ? IA32_EDX : dst_hi; + + if (dstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_hi)); + } + + if (sstk) + /* mov ecx,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX), + STACK_VAR(src_lo)); + else + /* mov ecx,src_lo */ + EMIT2(0x8B, add_2reg(0xC0, src_lo, IA32_ECX)); + + /* cmp ecx,32 */ + EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32); + /* Jumps when >= 32 */ + if (is_imm8(jmp_label(jmp_label1, 2))) + EMIT2(IA32_JAE, jmp_label(jmp_label1, 2)); + else + EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label1, 6)); + + /* < 32 */ + /* shl dreg_hi,cl */ + EMIT2(0xD3, add_1reg(0xE0, dreg_hi)); + /* mov ebx,dreg_lo */ + EMIT2(0x8B, add_2reg(0xC0, dreg_lo, IA32_EBX)); + /* shl dreg_lo,cl */ + EMIT2(0xD3, add_1reg(0xE0, dreg_lo)); + + /* IA32_ECX = -IA32_ECX + 32 */ + /* neg ecx */ + EMIT2(0xF7, add_1reg(0xD8, IA32_ECX)); + /* add ecx,32 */ + EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32); + + /* shr ebx,cl */ + EMIT2(0xD3, add_1reg(0xE8, IA32_EBX)); + /* or dreg_hi,ebx */ + EMIT2(0x09, add_2reg(0xC0, dreg_hi, IA32_EBX)); + + /* goto out; */ + if (is_imm8(jmp_label(jmp_label3, 2))) + EMIT2(0xEB, jmp_label(jmp_label3, 2)); + else + EMIT1_off32(0xE9, jmp_label(jmp_label3, 5)); + + /* >= 32 */ + if (jmp_label1 == -1) + jmp_label1 = cnt; + + /* cmp ecx,64 */ + EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 64); + /* Jumps when >= 64 */ + if (is_imm8(jmp_label(jmp_label2, 2))) + EMIT2(IA32_JAE, jmp_label(jmp_label2, 2)); + else + EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label2, 6)); + + /* >= 32 && < 64 */ + /* sub ecx,32 */ + EMIT3(0x83, add_1reg(0xE8, IA32_ECX), 32); + /* shl dreg_lo,cl */ + EMIT2(0xD3, add_1reg(0xE0, dreg_lo)); + /* mov dreg_hi,dreg_lo */ + EMIT2(0x89, add_2reg(0xC0, dreg_hi, dreg_lo)); + + /* xor dreg_lo,dreg_lo */ + EMIT2(0x33, add_2reg(0xC0, dreg_lo, dreg_lo)); + + /* goto out; */ + if (is_imm8(jmp_label(jmp_label3, 2))) + EMIT2(0xEB, jmp_label(jmp_label3, 2)); + else + EMIT1_off32(0xE9, jmp_label(jmp_label3, 5)); + + /* >= 64 */ + if (jmp_label2 == -1) + jmp_label2 = cnt; + /* xor dreg_lo,dreg_lo */ + EMIT2(0x33, add_2reg(0xC0, dreg_lo, dreg_lo)); + /* xor dreg_hi,dreg_hi */ + EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi)); + + if (jmp_label3 == -1) + jmp_label3 = cnt; + + if (dstk) { + /* mov dword ptr [ebp+off],dreg_lo */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_lo), + STACK_VAR(dst_lo)); + /* mov dword ptr [ebp+off],dreg_hi */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_hi), + STACK_VAR(dst_hi)); + } + /* out: */ + *pprog = prog; +} + +/* dst = dst >> src (signed)*/ +static inline void emit_ia32_arsh_r64(const u8 dst[], const u8 src[], + bool dstk, bool sstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + static int jmp_label1 = -1; + static int jmp_label2 = -1; + static int jmp_label3 = -1; + u8 dreg_lo = dstk ? IA32_EAX : dst_lo; + u8 dreg_hi = dstk ? IA32_EDX : dst_hi; + + if (dstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_hi)); + } + + if (sstk) + /* mov ecx,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX), + STACK_VAR(src_lo)); + else + /* mov ecx,src_lo */ + EMIT2(0x8B, add_2reg(0xC0, src_lo, IA32_ECX)); + + /* cmp ecx,32 */ + EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32); + /* Jumps when >= 32 */ + if (is_imm8(jmp_label(jmp_label1, 2))) + EMIT2(IA32_JAE, jmp_label(jmp_label1, 2)); + else + EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label1, 6)); + + /* < 32 */ + /* lshr dreg_lo,cl */ + EMIT2(0xD3, add_1reg(0xE8, dreg_lo)); + /* mov ebx,dreg_hi */ + EMIT2(0x8B, add_2reg(0xC0, dreg_hi, IA32_EBX)); + /* ashr dreg_hi,cl */ + EMIT2(0xD3, add_1reg(0xF8, dreg_hi)); + + /* IA32_ECX = -IA32_ECX + 32 */ + /* neg ecx */ + EMIT2(0xF7, add_1reg(0xD8, IA32_ECX)); + /* add ecx,32 */ + EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32); + + /* shl ebx,cl */ + EMIT2(0xD3, add_1reg(0xE0, IA32_EBX)); + /* or dreg_lo,ebx */ + EMIT2(0x09, add_2reg(0xC0, dreg_lo, IA32_EBX)); + + /* goto out; */ + if (is_imm8(jmp_label(jmp_label3, 2))) + EMIT2(0xEB, jmp_label(jmp_label3, 2)); + else + EMIT1_off32(0xE9, jmp_label(jmp_label3, 5)); + + /* >= 32 */ + if (jmp_label1 == -1) + jmp_label1 = cnt; + + /* cmp ecx,64 */ + EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 64); + /* Jumps when >= 64 */ + if (is_imm8(jmp_label(jmp_label2, 2))) + EMIT2(IA32_JAE, jmp_label(jmp_label2, 2)); + else + EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label2, 6)); + + /* >= 32 && < 64 */ + /* sub ecx,32 */ + EMIT3(0x83, add_1reg(0xE8, IA32_ECX), 32); + /* ashr dreg_hi,cl */ + EMIT2(0xD3, add_1reg(0xF8, dreg_hi)); + /* mov dreg_lo,dreg_hi */ + EMIT2(0x89, add_2reg(0xC0, dreg_lo, dreg_hi)); + + /* ashr dreg_hi,imm8 */ + EMIT3(0xC1, add_1reg(0xF8, dreg_hi), 31); + + /* goto out; */ + if (is_imm8(jmp_label(jmp_label3, 2))) + EMIT2(0xEB, jmp_label(jmp_label3, 2)); + else + EMIT1_off32(0xE9, jmp_label(jmp_label3, 5)); + + /* >= 64 */ + if (jmp_label2 == -1) + jmp_label2 = cnt; + /* ashr dreg_hi,imm8 */ + EMIT3(0xC1, add_1reg(0xF8, dreg_hi), 31); + /* mov dreg_lo,dreg_hi */ + EMIT2(0x89, add_2reg(0xC0, dreg_lo, dreg_hi)); + + if (jmp_label3 == -1) + jmp_label3 = cnt; + + if (dstk) { + /* mov dword ptr [ebp+off],dreg_lo */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_lo), + STACK_VAR(dst_lo)); + /* mov dword ptr [ebp+off],dreg_hi */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_hi), + STACK_VAR(dst_hi)); + } + /* out: */ + *pprog = prog; +} + +/* dst = dst >> src */ +static inline void emit_ia32_rsh_r64(const u8 dst[], const u8 src[], bool dstk, + bool sstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + static int jmp_label1 = -1; + static int jmp_label2 = -1; + static int jmp_label3 = -1; + u8 dreg_lo = dstk ? IA32_EAX : dst_lo; + u8 dreg_hi = dstk ? IA32_EDX : dst_hi; + + if (dstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_hi)); + } + + if (sstk) + /* mov ecx,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX), + STACK_VAR(src_lo)); + else + /* mov ecx,src_lo */ + EMIT2(0x8B, add_2reg(0xC0, src_lo, IA32_ECX)); + + /* cmp ecx,32 */ + EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32); + /* Jumps when >= 32 */ + if (is_imm8(jmp_label(jmp_label1, 2))) + EMIT2(IA32_JAE, jmp_label(jmp_label1, 2)); + else + EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label1, 6)); + + /* < 32 */ + /* lshr dreg_lo,cl */ + EMIT2(0xD3, add_1reg(0xE8, dreg_lo)); + /* mov ebx,dreg_hi */ + EMIT2(0x8B, add_2reg(0xC0, dreg_hi, IA32_EBX)); + /* shr dreg_hi,cl */ + EMIT2(0xD3, add_1reg(0xE8, dreg_hi)); + + /* IA32_ECX = -IA32_ECX + 32 */ + /* neg ecx */ + EMIT2(0xF7, add_1reg(0xD8, IA32_ECX)); + /* add ecx,32 */ + EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32); + + /* shl ebx,cl */ + EMIT2(0xD3, add_1reg(0xE0, IA32_EBX)); + /* or dreg_lo,ebx */ + EMIT2(0x09, add_2reg(0xC0, dreg_lo, IA32_EBX)); + + /* goto out; */ + if (is_imm8(jmp_label(jmp_label3, 2))) + EMIT2(0xEB, jmp_label(jmp_label3, 2)); + else + EMIT1_off32(0xE9, jmp_label(jmp_label3, 5)); + + /* >= 32 */ + if (jmp_label1 == -1) + jmp_label1 = cnt; + /* cmp ecx,64 */ + EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 64); + /* Jumps when >= 64 */ + if (is_imm8(jmp_label(jmp_label2, 2))) + EMIT2(IA32_JAE, jmp_label(jmp_label2, 2)); + else + EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label2, 6)); + + /* >= 32 && < 64 */ + /* sub ecx,32 */ + EMIT3(0x83, add_1reg(0xE8, IA32_ECX), 32); + /* shr dreg_hi,cl */ + EMIT2(0xD3, add_1reg(0xE8, dreg_hi)); + /* mov dreg_lo,dreg_hi */ + EMIT2(0x89, add_2reg(0xC0, dreg_lo, dreg_hi)); + /* xor dreg_hi,dreg_hi */ + EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi)); + + /* goto out; */ + if (is_imm8(jmp_label(jmp_label3, 2))) + EMIT2(0xEB, jmp_label(jmp_label3, 2)); + else + EMIT1_off32(0xE9, jmp_label(jmp_label3, 5)); + + /* >= 64 */ + if (jmp_label2 == -1) + jmp_label2 = cnt; + /* xor dreg_lo,dreg_lo */ + EMIT2(0x33, add_2reg(0xC0, dreg_lo, dreg_lo)); + /* xor dreg_hi,dreg_hi */ + EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi)); + + if (jmp_label3 == -1) + jmp_label3 = cnt; + + if (dstk) { + /* mov dword ptr [ebp+off],dreg_lo */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_lo), + STACK_VAR(dst_lo)); + /* mov dword ptr [ebp+off],dreg_hi */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_hi), + STACK_VAR(dst_hi)); + } + /* out: */ + *pprog = prog; +} + +/* dst = dst << val */ +static inline void emit_ia32_lsh_i64(const u8 dst[], const u32 val, + bool dstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + u8 dreg_lo = dstk ? IA32_EAX : dst_lo; + u8 dreg_hi = dstk ? IA32_EDX : dst_hi; + + if (dstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_hi)); + } + /* Do LSH operation */ + if (val < 32) { + /* shl dreg_hi,imm8 */ + EMIT3(0xC1, add_1reg(0xE0, dreg_hi), val); + /* mov ebx,dreg_lo */ + EMIT2(0x8B, add_2reg(0xC0, dreg_lo, IA32_EBX)); + /* shl dreg_lo,imm8 */ + EMIT3(0xC1, add_1reg(0xE0, dreg_lo), val); + + /* IA32_ECX = 32 - val */ + /* mov ecx,val */ + EMIT2(0xB1, val); + /* movzx ecx,ecx */ + EMIT3(0x0F, 0xB6, add_2reg(0xC0, IA32_ECX, IA32_ECX)); + /* neg ecx */ + EMIT2(0xF7, add_1reg(0xD8, IA32_ECX)); + /* add ecx,32 */ + EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32); + + /* shr ebx,cl */ + EMIT2(0xD3, add_1reg(0xE8, IA32_EBX)); + /* or dreg_hi,ebx */ + EMIT2(0x09, add_2reg(0xC0, dreg_hi, IA32_EBX)); + } else if (val >= 32 && val < 64) { + u32 value = val - 32; + + /* shl dreg_lo,imm8 */ + EMIT3(0xC1, add_1reg(0xE0, dreg_lo), value); + /* mov dreg_hi,dreg_lo */ + EMIT2(0x89, add_2reg(0xC0, dreg_hi, dreg_lo)); + /* xor dreg_lo,dreg_lo */ + EMIT2(0x33, add_2reg(0xC0, dreg_lo, dreg_lo)); + } else { + /* xor dreg_lo,dreg_lo */ + EMIT2(0x33, add_2reg(0xC0, dreg_lo, dreg_lo)); + /* xor dreg_hi,dreg_hi */ + EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi)); + } + + if (dstk) { + /* mov dword ptr [ebp+off],dreg_lo */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_lo), + STACK_VAR(dst_lo)); + /* mov dword ptr [ebp+off],dreg_hi */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_hi), + STACK_VAR(dst_hi)); + } + *pprog = prog; +} + +/* dst = dst >> val */ +static inline void emit_ia32_rsh_i64(const u8 dst[], const u32 val, + bool dstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + u8 dreg_lo = dstk ? IA32_EAX : dst_lo; + u8 dreg_hi = dstk ? IA32_EDX : dst_hi; + + if (dstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_hi)); + } + + /* Do RSH operation */ + if (val < 32) { + /* shr dreg_lo,imm8 */ + EMIT3(0xC1, add_1reg(0xE8, dreg_lo), val); + /* mov ebx,dreg_hi */ + EMIT2(0x8B, add_2reg(0xC0, dreg_hi, IA32_EBX)); + /* shr dreg_hi,imm8 */ + EMIT3(0xC1, add_1reg(0xE8, dreg_hi), val); + + /* IA32_ECX = 32 - val */ + /* mov ecx,val */ + EMIT2(0xB1, val); + /* movzx ecx,ecx */ + EMIT3(0x0F, 0xB6, add_2reg(0xC0, IA32_ECX, IA32_ECX)); + /* neg ecx */ + EMIT2(0xF7, add_1reg(0xD8, IA32_ECX)); + /* add ecx,32 */ + EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32); + + /* shl ebx,cl */ + EMIT2(0xD3, add_1reg(0xE0, IA32_EBX)); + /* or dreg_lo,ebx */ + EMIT2(0x09, add_2reg(0xC0, dreg_lo, IA32_EBX)); + } else if (val >= 32 && val < 64) { + u32 value = val - 32; + + /* shr dreg_hi,imm8 */ + EMIT3(0xC1, add_1reg(0xE8, dreg_hi), value); + /* mov dreg_lo,dreg_hi */ + EMIT2(0x89, add_2reg(0xC0, dreg_lo, dreg_hi)); + /* xor dreg_hi,dreg_hi */ + EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi)); + } else { + /* xor dreg_lo,dreg_lo */ + EMIT2(0x33, add_2reg(0xC0, dreg_lo, dreg_lo)); + /* xor dreg_hi,dreg_hi */ + EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi)); + } + + if (dstk) { + /* mov dword ptr [ebp+off],dreg_lo */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_lo), + STACK_VAR(dst_lo)); + /* mov dword ptr [ebp+off],dreg_hi */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_hi), + STACK_VAR(dst_hi)); + } + *pprog = prog; +} + +/* dst = dst >> val (signed) */ +static inline void emit_ia32_arsh_i64(const u8 dst[], const u32 val, + bool dstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + u8 dreg_lo = dstk ? IA32_EAX : dst_lo; + u8 dreg_hi = dstk ? IA32_EDX : dst_hi; + + if (dstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_hi)); + } + /* Do RSH operation */ + if (val < 32) { + /* shr dreg_lo,imm8 */ + EMIT3(0xC1, add_1reg(0xE8, dreg_lo), val); + /* mov ebx,dreg_hi */ + EMIT2(0x8B, add_2reg(0xC0, dreg_hi, IA32_EBX)); + /* ashr dreg_hi,imm8 */ + EMIT3(0xC1, add_1reg(0xF8, dreg_hi), val); + + /* IA32_ECX = 32 - val */ + /* mov ecx,val */ + EMIT2(0xB1, val); + /* movzx ecx,ecx */ + EMIT3(0x0F, 0xB6, add_2reg(0xC0, IA32_ECX, IA32_ECX)); + /* neg ecx */ + EMIT2(0xF7, add_1reg(0xD8, IA32_ECX)); + /* add ecx,32 */ + EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32); + + /* shl ebx,cl */ + EMIT2(0xD3, add_1reg(0xE0, IA32_EBX)); + /* or dreg_lo,ebx */ + EMIT2(0x09, add_2reg(0xC0, dreg_lo, IA32_EBX)); + } else if (val >= 32 && val < 64) { + u32 value = val - 32; + + /* ashr dreg_hi,imm8 */ + EMIT3(0xC1, add_1reg(0xF8, dreg_hi), value); + /* mov dreg_lo,dreg_hi */ + EMIT2(0x89, add_2reg(0xC0, dreg_lo, dreg_hi)); + + /* ashr dreg_hi,imm8 */ + EMIT3(0xC1, add_1reg(0xF8, dreg_hi), 31); + } else { + /* ashr dreg_hi,imm8 */ + EMIT3(0xC1, add_1reg(0xF8, dreg_hi), 31); + /* mov dreg_lo,dreg_hi */ + EMIT2(0x89, add_2reg(0xC0, dreg_lo, dreg_hi)); + } + + if (dstk) { + /* mov dword ptr [ebp+off],dreg_lo */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_lo), + STACK_VAR(dst_lo)); + /* mov dword ptr [ebp+off],dreg_hi */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_hi), + STACK_VAR(dst_hi)); + } + *pprog = prog; +} + +static inline void emit_ia32_mul_r64(const u8 dst[], const u8 src[], bool dstk, + bool sstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + + if (dstk) + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_hi)); + else + /* mov eax,dst_hi */ + EMIT2(0x8B, add_2reg(0xC0, dst_hi, IA32_EAX)); + + if (sstk) + /* mul dword ptr [ebp+off] */ + EMIT3(0xF7, add_1reg(0x60, IA32_EBP), STACK_VAR(src_lo)); + else + /* mul src_lo */ + EMIT2(0xF7, add_1reg(0xE0, src_lo)); + + /* mov ecx,eax */ + EMIT2(0x89, add_2reg(0xC0, IA32_ECX, IA32_EAX)); + + if (dstk) + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + else + /* mov eax,dst_lo */ + EMIT2(0x8B, add_2reg(0xC0, dst_lo, IA32_EAX)); + + if (sstk) + /* mul dword ptr [ebp+off] */ + EMIT3(0xF7, add_1reg(0x60, IA32_EBP), STACK_VAR(src_hi)); + else + /* mul src_hi */ + EMIT2(0xF7, add_1reg(0xE0, src_hi)); + + /* add eax,eax */ + EMIT2(0x01, add_2reg(0xC0, IA32_ECX, IA32_EAX)); + + if (dstk) + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + else + /* mov eax,dst_lo */ + EMIT2(0x8B, add_2reg(0xC0, dst_lo, IA32_EAX)); + + if (sstk) + /* mul dword ptr [ebp+off] */ + EMIT3(0xF7, add_1reg(0x60, IA32_EBP), STACK_VAR(src_lo)); + else + /* mul src_lo */ + EMIT2(0xF7, add_1reg(0xE0, src_lo)); + + /* add ecx,edx */ + EMIT2(0x01, add_2reg(0xC0, IA32_ECX, IA32_EDX)); + + if (dstk) { + /* mov dword ptr [ebp+off],eax */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + /* mov dword ptr [ebp+off],ecx */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_ECX), + STACK_VAR(dst_hi)); + } else { + /* mov dst_lo,eax */ + EMIT2(0x89, add_2reg(0xC0, dst_lo, IA32_EAX)); + /* mov dst_hi,ecx */ + EMIT2(0x89, add_2reg(0xC0, dst_hi, IA32_ECX)); + } + + *pprog = prog; +} + +static inline void emit_ia32_mul_i64(const u8 dst[], const u32 val, + bool dstk, u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + u32 hi; + + hi = val & (1<<31) ? (u32)~0 : 0; + /* movl eax,imm32 */ + EMIT2_off32(0xC7, add_1reg(0xC0, IA32_EAX), val); + if (dstk) + /* mul dword ptr [ebp+off] */ + EMIT3(0xF7, add_1reg(0x60, IA32_EBP), STACK_VAR(dst_hi)); + else + /* mul dst_hi */ + EMIT2(0xF7, add_1reg(0xE0, dst_hi)); + + /* mov ecx,eax */ + EMIT2(0x89, add_2reg(0xC0, IA32_ECX, IA32_EAX)); + + /* movl eax,imm32 */ + EMIT2_off32(0xC7, add_1reg(0xC0, IA32_EAX), hi); + if (dstk) + /* mul dword ptr [ebp+off] */ + EMIT3(0xF7, add_1reg(0x60, IA32_EBP), STACK_VAR(dst_lo)); + else + /* mul dst_lo */ + EMIT2(0xF7, add_1reg(0xE0, dst_lo)); + /* add ecx,eax */ + EMIT2(0x01, add_2reg(0xC0, IA32_ECX, IA32_EAX)); + + /* movl eax,imm32 */ + EMIT2_off32(0xC7, add_1reg(0xC0, IA32_EAX), val); + if (dstk) + /* mul dword ptr [ebp+off] */ + EMIT3(0xF7, add_1reg(0x60, IA32_EBP), STACK_VAR(dst_lo)); + else + /* mul dst_lo */ + EMIT2(0xF7, add_1reg(0xE0, dst_lo)); + + /* add ecx,edx */ + EMIT2(0x01, add_2reg(0xC0, IA32_ECX, IA32_EDX)); + + if (dstk) { + /* mov dword ptr [ebp+off],eax */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + /* mov dword ptr [ebp+off],ecx */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_ECX), + STACK_VAR(dst_hi)); + } else { + /* mov dword ptr [ebp+off],eax */ + EMIT2(0x89, add_2reg(0xC0, dst_lo, IA32_EAX)); + /* mov dword ptr [ebp+off],ecx */ + EMIT2(0x89, add_2reg(0xC0, dst_hi, IA32_ECX)); + } + + *pprog = prog; +} + +static int bpf_size_to_x86_bytes(int bpf_size) +{ + if (bpf_size == BPF_W) + return 4; + else if (bpf_size == BPF_H) + return 2; + else if (bpf_size == BPF_B) + return 1; + else if (bpf_size == BPF_DW) + return 4; /* imm32 */ + else + return 0; +} + +struct jit_context { + int cleanup_addr; /* Epilogue code offset */ +}; + +/* Maximum number of bytes emitted while JITing one eBPF insn */ +#define BPF_MAX_INSN_SIZE 128 +#define BPF_INSN_SAFETY 64 + +#define PROLOGUE_SIZE 35 + +/* + * Emit prologue code for BPF program and check it's size. + * bpf_tail_call helper will skip it while jumping into another program. + */ +static void emit_prologue(u8 **pprog, u32 stack_depth) +{ + u8 *prog = *pprog; + int cnt = 0; + const u8 *r1 = bpf2ia32[BPF_REG_1]; + const u8 fplo = bpf2ia32[BPF_REG_FP][0]; + const u8 fphi = bpf2ia32[BPF_REG_FP][1]; + const u8 *tcc = bpf2ia32[TCALL_CNT]; + + /* push ebp */ + EMIT1(0x55); + /* mov ebp,esp */ + EMIT2(0x89, 0xE5); + /* push edi */ + EMIT1(0x57); + /* push esi */ + EMIT1(0x56); + /* push ebx */ + EMIT1(0x53); + + /* sub esp,STACK_SIZE */ + EMIT2_off32(0x81, 0xEC, STACK_SIZE); + /* sub ebp,SCRATCH_SIZE+4+12*/ + EMIT3(0x83, add_1reg(0xE8, IA32_EBP), SCRATCH_SIZE + 16); + /* xor ebx,ebx */ + EMIT2(0x31, add_2reg(0xC0, IA32_EBX, IA32_EBX)); + + /* Set up BPF prog stack base register */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EBP), STACK_VAR(fplo)); + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EBX), STACK_VAR(fphi)); + + /* Move BPF_CTX (EAX) to BPF_REG_R1 */ + /* mov dword ptr [ebp+off],eax */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EAX), STACK_VAR(r1[0])); + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EBX), STACK_VAR(r1[1])); + + /* Initialize Tail Count */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EBX), STACK_VAR(tcc[0])); + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EBX), STACK_VAR(tcc[1])); + + BUILD_BUG_ON(cnt != PROLOGUE_SIZE); + *pprog = prog; +} + +/* Emit epilogue code for BPF program */ +static void emit_epilogue(u8 **pprog, u32 stack_depth) +{ + u8 *prog = *pprog; + const u8 *r0 = bpf2ia32[BPF_REG_0]; + int cnt = 0; + + /* mov eax,dword ptr [ebp+off]*/ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), STACK_VAR(r0[0])); + /* mov edx,dword ptr [ebp+off]*/ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), STACK_VAR(r0[1])); + + /* add ebp,SCRATCH_SIZE+4+12*/ + EMIT3(0x83, add_1reg(0xC0, IA32_EBP), SCRATCH_SIZE + 16); + + /* mov ebx,dword ptr [ebp-12]*/ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EBX), -12); + /* mov esi,dword ptr [ebp-8]*/ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ESI), -8); + /* mov edi,dword ptr [ebp-4]*/ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDI), -4); + + EMIT1(0xC9); /* leave */ + EMIT1(0xC3); /* ret */ + *pprog = prog; +} + +/* + * Generate the following code: + * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... + * if (index >= array->map.max_entries) + * goto out; + * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) + * goto out; + * prog = array->ptrs[index]; + * if (prog == NULL) + * goto out; + * goto *(prog->bpf_func + prologue_size); + * out: + */ +static void emit_bpf_tail_call(u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + const u8 *r1 = bpf2ia32[BPF_REG_1]; + const u8 *r2 = bpf2ia32[BPF_REG_2]; + const u8 *r3 = bpf2ia32[BPF_REG_3]; + const u8 *tcc = bpf2ia32[TCALL_CNT]; + u32 lo, hi; + static int jmp_label1 = -1; + + /* + * if (index >= array->map.max_entries) + * goto out; + */ + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), STACK_VAR(r2[0])); + /* mov edx,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), STACK_VAR(r3[0])); + + /* cmp dword ptr [eax+off],edx */ + EMIT3(0x39, add_2reg(0x40, IA32_EAX, IA32_EDX), + offsetof(struct bpf_array, map.max_entries)); + /* jbe out */ + EMIT2(IA32_JBE, jmp_label(jmp_label1, 2)); + + /* + * if (tail_call_cnt > MAX_TAIL_CALL_CNT) + * goto out; + */ + lo = (u32)MAX_TAIL_CALL_CNT; + hi = (u32)((u64)MAX_TAIL_CALL_CNT >> 32); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX), STACK_VAR(tcc[0])); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EBX), STACK_VAR(tcc[1])); + + /* cmp edx,hi */ + EMIT3(0x83, add_1reg(0xF8, IA32_EBX), hi); + EMIT2(IA32_JNE, 3); + /* cmp ecx,lo */ + EMIT3(0x83, add_1reg(0xF8, IA32_ECX), lo); + + /* ja out */ + EMIT2(IA32_JAE, jmp_label(jmp_label1, 2)); + + /* add eax,0x1 */ + EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 0x01); + /* adc ebx,0x0 */ + EMIT3(0x83, add_1reg(0xD0, IA32_EBX), 0x00); + + /* mov dword ptr [ebp+off],eax */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_ECX), STACK_VAR(tcc[0])); + /* mov dword ptr [ebp+off],edx */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EBX), STACK_VAR(tcc[1])); + + /* prog = array->ptrs[index]; */ + /* mov edx, [eax + edx * 4 + offsetof(...)] */ + EMIT3_off32(0x8B, 0x94, 0x90, offsetof(struct bpf_array, ptrs)); + + /* + * if (prog == NULL) + * goto out; + */ + /* test edx,edx */ + EMIT2(0x85, add_2reg(0xC0, IA32_EDX, IA32_EDX)); + /* je out */ + EMIT2(IA32_JE, jmp_label(jmp_label1, 2)); + + /* goto *(prog->bpf_func + prologue_size); */ + /* mov edx, dword ptr [edx + 32] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EDX, IA32_EDX), + offsetof(struct bpf_prog, bpf_func)); + /* add edx,prologue_size */ + EMIT3(0x83, add_1reg(0xC0, IA32_EDX), PROLOGUE_SIZE); + + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), STACK_VAR(r1[0])); + + /* + * Now we're ready to jump into next BPF program: + * eax == ctx (1st arg) + * edx == prog->bpf_func + prologue_size + */ + RETPOLINE_EDX_BPF_JIT(); + + if (jmp_label1 == -1) + jmp_label1 = cnt; + + /* out: */ + *pprog = prog; +} + +/* Push the scratch stack register on top of the stack. */ +static inline void emit_push_r64(const u8 src[], u8 **pprog) +{ + u8 *prog = *pprog; + int cnt = 0; + + /* mov ecx,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX), STACK_VAR(src_hi)); + /* push ecx */ + EMIT1(0x51); + + /* mov ecx,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX), STACK_VAR(src_lo)); + /* push ecx */ + EMIT1(0x51); + + *pprog = prog; +} + +static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, + int oldproglen, struct jit_context *ctx) +{ + struct bpf_insn *insn = bpf_prog->insnsi; + int insn_cnt = bpf_prog->len; + bool seen_exit = false; + u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; + int i, cnt = 0; + int proglen = 0; + u8 *prog = temp; + + emit_prologue(&prog, bpf_prog->aux->stack_depth); + + for (i = 0; i < insn_cnt; i++, insn++) { + const s32 imm32 = insn->imm; + const bool is64 = BPF_CLASS(insn->code) == BPF_ALU64; + const bool dstk = insn->dst_reg == BPF_REG_AX ? false : true; + const bool sstk = insn->src_reg == BPF_REG_AX ? false : true; + const u8 code = insn->code; + const u8 *dst = bpf2ia32[insn->dst_reg]; + const u8 *src = bpf2ia32[insn->src_reg]; + const u8 *r0 = bpf2ia32[BPF_REG_0]; + s64 jmp_offset; + u8 jmp_cond; + int ilen; + u8 *func; + + switch (code) { + /* ALU operations */ + /* dst = src */ + case BPF_ALU | BPF_MOV | BPF_K: + case BPF_ALU | BPF_MOV | BPF_X: + case BPF_ALU64 | BPF_MOV | BPF_K: + case BPF_ALU64 | BPF_MOV | BPF_X: + switch (BPF_SRC(code)) { + case BPF_X: + emit_ia32_mov_r64(is64, dst, src, dstk, + sstk, &prog); + break; + case BPF_K: + /* Sign-extend immediate value to dst reg */ + emit_ia32_mov_i64(is64, dst, imm32, + dstk, &prog); + break; + } + break; + /* dst = dst + src/imm */ + /* dst = dst - src/imm */ + /* dst = dst | src/imm */ + /* dst = dst & src/imm */ + /* dst = dst ^ src/imm */ + /* dst = dst * src/imm */ + /* dst = dst << src */ + /* dst = dst >> src */ + case BPF_ALU | BPF_ADD | BPF_K: + case BPF_ALU | BPF_ADD | BPF_X: + case BPF_ALU | BPF_SUB | BPF_K: + case BPF_ALU | BPF_SUB | BPF_X: + case BPF_ALU | BPF_OR | BPF_K: + case BPF_ALU | BPF_OR | BPF_X: + case BPF_ALU | BPF_AND | BPF_K: + case BPF_ALU | BPF_AND | BPF_X: + case BPF_ALU | BPF_XOR | BPF_K: + case BPF_ALU | BPF_XOR | BPF_X: + case BPF_ALU64 | BPF_ADD | BPF_K: + case BPF_ALU64 | BPF_ADD | BPF_X: + case BPF_ALU64 | BPF_SUB | BPF_K: + case BPF_ALU64 | BPF_SUB | BPF_X: + case BPF_ALU64 | BPF_OR | BPF_K: + case BPF_ALU64 | BPF_OR | BPF_X: + case BPF_ALU64 | BPF_AND | BPF_K: + case BPF_ALU64 | BPF_AND | BPF_X: + case BPF_ALU64 | BPF_XOR | BPF_K: + case BPF_ALU64 | BPF_XOR | BPF_X: + switch (BPF_SRC(code)) { + case BPF_X: + emit_ia32_alu_r64(is64, BPF_OP(code), dst, + src, dstk, sstk, &prog); + break; + case BPF_K: + emit_ia32_alu_i64(is64, BPF_OP(code), dst, + imm32, dstk, &prog); + break; + } + break; + case BPF_ALU | BPF_MUL | BPF_K: + case BPF_ALU | BPF_MUL | BPF_X: + switch (BPF_SRC(code)) { + case BPF_X: + emit_ia32_mul_r(dst_lo, src_lo, dstk, + sstk, &prog); + break; + case BPF_K: + /* mov ecx,imm32*/ + EMIT2_off32(0xC7, add_1reg(0xC0, IA32_ECX), + imm32); + emit_ia32_mul_r(dst_lo, IA32_ECX, dstk, + false, &prog); + break; + } + emit_ia32_mov_i(dst_hi, 0, dstk, &prog); + break; + case BPF_ALU | BPF_LSH | BPF_X: + case BPF_ALU | BPF_RSH | BPF_X: + case BPF_ALU | BPF_ARSH | BPF_K: + case BPF_ALU | BPF_ARSH | BPF_X: + switch (BPF_SRC(code)) { + case BPF_X: + emit_ia32_shift_r(BPF_OP(code), dst_lo, src_lo, + dstk, sstk, &prog); + break; + case BPF_K: + /* mov ecx,imm32*/ + EMIT2_off32(0xC7, add_1reg(0xC0, IA32_ECX), + imm32); + emit_ia32_shift_r(BPF_OP(code), dst_lo, + IA32_ECX, dstk, false, + &prog); + break; + } + emit_ia32_mov_i(dst_hi, 0, dstk, &prog); + break; + /* dst = dst / src(imm) */ + /* dst = dst % src(imm) */ + case BPF_ALU | BPF_DIV | BPF_K: + case BPF_ALU | BPF_DIV | BPF_X: + case BPF_ALU | BPF_MOD | BPF_K: + case BPF_ALU | BPF_MOD | BPF_X: + switch (BPF_SRC(code)) { + case BPF_X: + emit_ia32_div_mod_r(BPF_OP(code), dst_lo, + src_lo, dstk, sstk, &prog); + break; + case BPF_K: + /* mov ecx,imm32*/ + EMIT2_off32(0xC7, add_1reg(0xC0, IA32_ECX), + imm32); + emit_ia32_div_mod_r(BPF_OP(code), dst_lo, + IA32_ECX, dstk, false, + &prog); + break; + } + emit_ia32_mov_i(dst_hi, 0, dstk, &prog); + break; + case BPF_ALU64 | BPF_DIV | BPF_K: + case BPF_ALU64 | BPF_DIV | BPF_X: + case BPF_ALU64 | BPF_MOD | BPF_K: + case BPF_ALU64 | BPF_MOD | BPF_X: + goto notyet; + /* dst = dst >> imm */ + /* dst = dst << imm */ + case BPF_ALU | BPF_RSH | BPF_K: + case BPF_ALU | BPF_LSH | BPF_K: + if (unlikely(imm32 > 31)) + return -EINVAL; + /* mov ecx,imm32*/ + EMIT2_off32(0xC7, add_1reg(0xC0, IA32_ECX), imm32); + emit_ia32_shift_r(BPF_OP(code), dst_lo, IA32_ECX, dstk, + false, &prog); + emit_ia32_mov_i(dst_hi, 0, dstk, &prog); + break; + /* dst = dst << imm */ + case BPF_ALU64 | BPF_LSH | BPF_K: + if (unlikely(imm32 > 63)) + return -EINVAL; + emit_ia32_lsh_i64(dst, imm32, dstk, &prog); + break; + /* dst = dst >> imm */ + case BPF_ALU64 | BPF_RSH | BPF_K: + if (unlikely(imm32 > 63)) + return -EINVAL; + emit_ia32_rsh_i64(dst, imm32, dstk, &prog); + break; + /* dst = dst << src */ + case BPF_ALU64 | BPF_LSH | BPF_X: + emit_ia32_lsh_r64(dst, src, dstk, sstk, &prog); + break; + /* dst = dst >> src */ + case BPF_ALU64 | BPF_RSH | BPF_X: + emit_ia32_rsh_r64(dst, src, dstk, sstk, &prog); + break; + /* dst = dst >> src (signed) */ + case BPF_ALU64 | BPF_ARSH | BPF_X: + emit_ia32_arsh_r64(dst, src, dstk, sstk, &prog); + break; + /* dst = dst >> imm (signed) */ + case BPF_ALU64 | BPF_ARSH | BPF_K: + if (unlikely(imm32 > 63)) + return -EINVAL; + emit_ia32_arsh_i64(dst, imm32, dstk, &prog); + break; + /* dst = ~dst */ + case BPF_ALU | BPF_NEG: + emit_ia32_alu_i(is64, false, BPF_OP(code), + dst_lo, 0, dstk, &prog); + emit_ia32_mov_i(dst_hi, 0, dstk, &prog); + break; + /* dst = ~dst (64 bit) */ + case BPF_ALU64 | BPF_NEG: + emit_ia32_neg64(dst, dstk, &prog); + break; + /* dst = dst * src/imm */ + case BPF_ALU64 | BPF_MUL | BPF_X: + case BPF_ALU64 | BPF_MUL | BPF_K: + switch (BPF_SRC(code)) { + case BPF_X: + emit_ia32_mul_r64(dst, src, dstk, sstk, &prog); + break; + case BPF_K: + emit_ia32_mul_i64(dst, imm32, dstk, &prog); + break; + } + break; + /* dst = htole(dst) */ + case BPF_ALU | BPF_END | BPF_FROM_LE: + emit_ia32_to_le_r64(dst, imm32, dstk, &prog); + break; + /* dst = htobe(dst) */ + case BPF_ALU | BPF_END | BPF_FROM_BE: + emit_ia32_to_be_r64(dst, imm32, dstk, &prog); + break; + /* dst = imm64 */ + case BPF_LD | BPF_IMM | BPF_DW: { + s32 hi, lo = imm32; + + hi = insn[1].imm; + emit_ia32_mov_i(dst_lo, lo, dstk, &prog); + emit_ia32_mov_i(dst_hi, hi, dstk, &prog); + insn++; + i++; + break; + } + /* ST: *(u8*)(dst_reg + off) = imm */ + case BPF_ST | BPF_MEM | BPF_H: + case BPF_ST | BPF_MEM | BPF_B: + case BPF_ST | BPF_MEM | BPF_W: + case BPF_ST | BPF_MEM | BPF_DW: + if (dstk) + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + else + /* mov eax,dst_lo */ + EMIT2(0x8B, add_2reg(0xC0, dst_lo, IA32_EAX)); + + switch (BPF_SIZE(code)) { + case BPF_B: + EMIT(0xC6, 1); break; + case BPF_H: + EMIT2(0x66, 0xC7); break; + case BPF_W: + case BPF_DW: + EMIT(0xC7, 1); break; + } + + if (is_imm8(insn->off)) + EMIT2(add_1reg(0x40, IA32_EAX), insn->off); + else + EMIT1_off32(add_1reg(0x80, IA32_EAX), + insn->off); + EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(code))); + + if (BPF_SIZE(code) == BPF_DW) { + u32 hi; + + hi = imm32 & (1<<31) ? (u32)~0 : 0; + EMIT2_off32(0xC7, add_1reg(0x80, IA32_EAX), + insn->off + 4); + EMIT(hi, 4); + } + break; + + /* STX: *(u8*)(dst_reg + off) = src_reg */ + case BPF_STX | BPF_MEM | BPF_B: + case BPF_STX | BPF_MEM | BPF_H: + case BPF_STX | BPF_MEM | BPF_W: + case BPF_STX | BPF_MEM | BPF_DW: + if (dstk) + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + else + /* mov eax,dst_lo */ + EMIT2(0x8B, add_2reg(0xC0, dst_lo, IA32_EAX)); + + if (sstk) + /* mov edx,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(src_lo)); + else + /* mov edx,src_lo */ + EMIT2(0x8B, add_2reg(0xC0, src_lo, IA32_EDX)); + + switch (BPF_SIZE(code)) { + case BPF_B: + EMIT(0x88, 1); break; + case BPF_H: + EMIT2(0x66, 0x89); break; + case BPF_W: + case BPF_DW: + EMIT(0x89, 1); break; + } + + if (is_imm8(insn->off)) + EMIT2(add_2reg(0x40, IA32_EAX, IA32_EDX), + insn->off); + else + EMIT1_off32(add_2reg(0x80, IA32_EAX, IA32_EDX), + insn->off); + + if (BPF_SIZE(code) == BPF_DW) { + if (sstk) + /* mov edi,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, + IA32_EDX), + STACK_VAR(src_hi)); + else + /* mov edi,src_hi */ + EMIT2(0x8B, add_2reg(0xC0, src_hi, + IA32_EDX)); + EMIT1(0x89); + if (is_imm8(insn->off + 4)) { + EMIT2(add_2reg(0x40, IA32_EAX, + IA32_EDX), + insn->off + 4); + } else { + EMIT1(add_2reg(0x80, IA32_EAX, + IA32_EDX)); + EMIT(insn->off + 4, 4); + } + } + break; + + /* LDX: dst_reg = *(u8*)(src_reg + off) */ + case BPF_LDX | BPF_MEM | BPF_B: + case BPF_LDX | BPF_MEM | BPF_H: + case BPF_LDX | BPF_MEM | BPF_W: + case BPF_LDX | BPF_MEM | BPF_DW: + if (sstk) + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(src_lo)); + else + /* mov eax,dword ptr [ebp+off] */ + EMIT2(0x8B, add_2reg(0xC0, src_lo, IA32_EAX)); + + switch (BPF_SIZE(code)) { + case BPF_B: + EMIT2(0x0F, 0xB6); break; + case BPF_H: + EMIT2(0x0F, 0xB7); break; + case BPF_W: + case BPF_DW: + EMIT(0x8B, 1); break; + } + + if (is_imm8(insn->off)) + EMIT2(add_2reg(0x40, IA32_EAX, IA32_EDX), + insn->off); + else + EMIT1_off32(add_2reg(0x80, IA32_EAX, IA32_EDX), + insn->off); + + if (dstk) + /* mov dword ptr [ebp+off],edx */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_lo)); + else + /* mov dst_lo,edx */ + EMIT2(0x89, add_2reg(0xC0, dst_lo, IA32_EDX)); + switch (BPF_SIZE(code)) { + case BPF_B: + case BPF_H: + case BPF_W: + if (dstk) { + EMIT3(0xC7, add_1reg(0x40, IA32_EBP), + STACK_VAR(dst_hi)); + EMIT(0x0, 4); + } else { + EMIT3(0xC7, add_1reg(0xC0, dst_hi), 0); + } + break; + case BPF_DW: + EMIT2_off32(0x8B, + add_2reg(0x80, IA32_EAX, IA32_EDX), + insn->off + 4); + if (dstk) + EMIT3(0x89, + add_2reg(0x40, IA32_EBP, + IA32_EDX), + STACK_VAR(dst_hi)); + else + EMIT2(0x89, + add_2reg(0xC0, dst_hi, IA32_EDX)); + break; + default: + break; + } + break; + /* call */ + case BPF_JMP | BPF_CALL: + { + const u8 *r1 = bpf2ia32[BPF_REG_1]; + const u8 *r2 = bpf2ia32[BPF_REG_2]; + const u8 *r3 = bpf2ia32[BPF_REG_3]; + const u8 *r4 = bpf2ia32[BPF_REG_4]; + const u8 *r5 = bpf2ia32[BPF_REG_5]; + + if (insn->src_reg == BPF_PSEUDO_CALL) + goto notyet; + + func = (u8 *) __bpf_call_base + imm32; + jmp_offset = func - (image + addrs[i]); + + if (!imm32 || !is_simm32(jmp_offset)) { + pr_err("unsupported BPF func %d addr %p image %p\n", + imm32, func, image); + return -EINVAL; + } + + /* mov eax,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(r1[0])); + /* mov edx,dword ptr [ebp+off] */ + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(r1[1])); + + emit_push_r64(r5, &prog); + emit_push_r64(r4, &prog); + emit_push_r64(r3, &prog); + emit_push_r64(r2, &prog); + + EMIT1_off32(0xE8, jmp_offset + 9); + + /* mov dword ptr [ebp+off],eax */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(r0[0])); + /* mov dword ptr [ebp+off],edx */ + EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(r0[1])); + + /* add esp,32 */ + EMIT3(0x83, add_1reg(0xC0, IA32_ESP), 32); + break; + } + case BPF_JMP | BPF_TAIL_CALL: + emit_bpf_tail_call(&prog); + break; + + /* cond jump */ + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP | BPF_JNE | BPF_X: + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JLT | BPF_X: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JLE | BPF_X: + case BPF_JMP | BPF_JSGT | BPF_X: + case BPF_JMP | BPF_JSLE | BPF_X: + case BPF_JMP | BPF_JSLT | BPF_X: + case BPF_JMP | BPF_JSGE | BPF_X: { + u8 dreg_lo = dstk ? IA32_EAX : dst_lo; + u8 dreg_hi = dstk ? IA32_EDX : dst_hi; + u8 sreg_lo = sstk ? IA32_ECX : src_lo; + u8 sreg_hi = sstk ? IA32_EBX : src_hi; + + if (dstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_hi)); + } + + if (sstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX), + STACK_VAR(src_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EBX), + STACK_VAR(src_hi)); + } + + /* cmp dreg_hi,sreg_hi */ + EMIT2(0x39, add_2reg(0xC0, dreg_hi, sreg_hi)); + EMIT2(IA32_JNE, 2); + /* cmp dreg_lo,sreg_lo */ + EMIT2(0x39, add_2reg(0xC0, dreg_lo, sreg_lo)); + goto emit_cond_jmp; + } + case BPF_JMP | BPF_JSET | BPF_X: { + u8 dreg_lo = dstk ? IA32_EAX : dst_lo; + u8 dreg_hi = dstk ? IA32_EDX : dst_hi; + u8 sreg_lo = sstk ? IA32_ECX : src_lo; + u8 sreg_hi = sstk ? IA32_EBX : src_hi; + + if (dstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_hi)); + } + + if (sstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX), + STACK_VAR(src_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EBX), + STACK_VAR(src_hi)); + } + /* and dreg_lo,sreg_lo */ + EMIT2(0x23, add_2reg(0xC0, sreg_lo, dreg_lo)); + /* and dreg_hi,sreg_hi */ + EMIT2(0x23, add_2reg(0xC0, sreg_hi, dreg_hi)); + /* or dreg_lo,dreg_hi */ + EMIT2(0x09, add_2reg(0xC0, dreg_lo, dreg_hi)); + goto emit_cond_jmp; + } + case BPF_JMP | BPF_JSET | BPF_K: { + u32 hi; + u8 dreg_lo = dstk ? IA32_EAX : dst_lo; + u8 dreg_hi = dstk ? IA32_EDX : dst_hi; + u8 sreg_lo = IA32_ECX; + u8 sreg_hi = IA32_EBX; + + if (dstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_hi)); + } + hi = imm32 & (1<<31) ? (u32)~0 : 0; + + /* mov ecx,imm32 */ + EMIT2_off32(0xC7, add_1reg(0xC0, IA32_ECX), imm32); + /* mov ebx,imm32 */ + EMIT2_off32(0xC7, add_1reg(0xC0, IA32_EBX), hi); + + /* and dreg_lo,sreg_lo */ + EMIT2(0x23, add_2reg(0xC0, sreg_lo, dreg_lo)); + /* and dreg_hi,sreg_hi */ + EMIT2(0x23, add_2reg(0xC0, sreg_hi, dreg_hi)); + /* or dreg_lo,dreg_hi */ + EMIT2(0x09, add_2reg(0xC0, dreg_lo, dreg_hi)); + goto emit_cond_jmp; + } + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JNE | BPF_K: + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JLT | BPF_K: + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JLE | BPF_K: + case BPF_JMP | BPF_JSGT | BPF_K: + case BPF_JMP | BPF_JSLE | BPF_K: + case BPF_JMP | BPF_JSLT | BPF_K: + case BPF_JMP | BPF_JSGE | BPF_K: { + u32 hi; + u8 dreg_lo = dstk ? IA32_EAX : dst_lo; + u8 dreg_hi = dstk ? IA32_EDX : dst_hi; + u8 sreg_lo = IA32_ECX; + u8 sreg_hi = IA32_EBX; + + if (dstk) { + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX), + STACK_VAR(dst_lo)); + EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), + STACK_VAR(dst_hi)); + } + + hi = imm32 & (1<<31) ? (u32)~0 : 0; + /* mov ecx,imm32 */ + EMIT2_off32(0xC7, add_1reg(0xC0, IA32_ECX), imm32); + /* mov ebx,imm32 */ + EMIT2_off32(0xC7, add_1reg(0xC0, IA32_EBX), hi); + + /* cmp dreg_hi,sreg_hi */ + EMIT2(0x39, add_2reg(0xC0, dreg_hi, sreg_hi)); + EMIT2(IA32_JNE, 2); + /* cmp dreg_lo,sreg_lo */ + EMIT2(0x39, add_2reg(0xC0, dreg_lo, sreg_lo)); + +emit_cond_jmp: /* Convert BPF opcode to x86 */ + switch (BPF_OP(code)) { + case BPF_JEQ: + jmp_cond = IA32_JE; + break; + case BPF_JSET: + case BPF_JNE: + jmp_cond = IA32_JNE; + break; + case BPF_JGT: + /* GT is unsigned '>', JA in x86 */ + jmp_cond = IA32_JA; + break; + case BPF_JLT: + /* LT is unsigned '<', JB in x86 */ + jmp_cond = IA32_JB; + break; + case BPF_JGE: + /* GE is unsigned '>=', JAE in x86 */ + jmp_cond = IA32_JAE; + break; + case BPF_JLE: + /* LE is unsigned '<=', JBE in x86 */ + jmp_cond = IA32_JBE; + break; + case BPF_JSGT: + /* Signed '>', GT in x86 */ + jmp_cond = IA32_JG; + break; + case BPF_JSLT: + /* Signed '<', LT in x86 */ + jmp_cond = IA32_JL; + break; + case BPF_JSGE: + /* Signed '>=', GE in x86 */ + jmp_cond = IA32_JGE; + break; + case BPF_JSLE: + /* Signed '<=', LE in x86 */ + jmp_cond = IA32_JLE; + break; + default: /* to silence GCC warning */ + return -EFAULT; + } + jmp_offset = addrs[i + insn->off] - addrs[i]; + if (is_imm8(jmp_offset)) { + EMIT2(jmp_cond, jmp_offset); + } else if (is_simm32(jmp_offset)) { + EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); + } else { + pr_err("cond_jmp gen bug %llx\n", jmp_offset); + return -EFAULT; + } + + break; + } + case BPF_JMP | BPF_JA: + if (insn->off == -1) + /* -1 jmp instructions will always jump + * backwards two bytes. Explicitly handling + * this case avoids wasting too many passes + * when there are long sequences of replaced + * dead code. + */ + jmp_offset = -2; + else + jmp_offset = addrs[i + insn->off] - addrs[i]; + + if (!jmp_offset) + /* Optimize out nop jumps */ + break; +emit_jmp: + if (is_imm8(jmp_offset)) { + EMIT2(0xEB, jmp_offset); + } else if (is_simm32(jmp_offset)) { + EMIT1_off32(0xE9, jmp_offset); + } else { + pr_err("jmp gen bug %llx\n", jmp_offset); + return -EFAULT; + } + break; + /* STX XADD: lock *(u32 *)(dst + off) += src */ + case BPF_STX | BPF_XADD | BPF_W: + /* STX XADD: lock *(u64 *)(dst + off) += src */ + case BPF_STX | BPF_XADD | BPF_DW: + goto notyet; + case BPF_JMP | BPF_EXIT: + if (seen_exit) { + jmp_offset = ctx->cleanup_addr - addrs[i]; + goto emit_jmp; + } + seen_exit = true; + /* Update cleanup_addr */ + ctx->cleanup_addr = proglen; + emit_epilogue(&prog, bpf_prog->aux->stack_depth); + break; +notyet: + pr_info_once("*** NOT YET: opcode %02x ***\n", code); + return -EFAULT; + default: + /* + * This error will be seen if new instruction was added + * to interpreter, but not to JIT or if there is junk in + * bpf_prog + */ + pr_err("bpf_jit: unknown opcode %02x\n", code); + return -EINVAL; + } + + ilen = prog - temp; + if (ilen > BPF_MAX_INSN_SIZE) { + pr_err("bpf_jit: fatal insn size error\n"); + return -EFAULT; + } + + if (image) { + if (unlikely(proglen + ilen > oldproglen)) { + pr_err("bpf_jit: fatal error\n"); + return -EFAULT; + } + memcpy(image + proglen, temp, ilen); + } + proglen += ilen; + addrs[i] = proglen; + prog = temp; + } + return proglen; +} + +struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) +{ + struct bpf_binary_header *header = NULL; + struct bpf_prog *tmp, *orig_prog = prog; + int proglen, oldproglen = 0; + struct jit_context ctx = {}; + bool tmp_blinded = false; + u8 *image = NULL; + int *addrs; + int pass; + int i; + + if (!prog->jit_requested) + return orig_prog; + + tmp = bpf_jit_blind_constants(prog); + /* + * If blinding was requested and we failed during blinding, + * we must fall back to the interpreter. + */ + if (IS_ERR(tmp)) + return orig_prog; + if (tmp != prog) { + tmp_blinded = true; + prog = tmp; + } + + addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL); + if (!addrs) { + prog = orig_prog; + goto out; + } + + /* + * Before first pass, make a rough estimation of addrs[] + * each BPF instruction is translated to less than 64 bytes + */ + for (proglen = 0, i = 0; i < prog->len; i++) { + proglen += 64; + addrs[i] = proglen; + } + ctx.cleanup_addr = proglen; + + /* + * JITed image shrinks with every pass and the loop iterates + * until the image stops shrinking. Very large BPF programs + * may converge on the last pass. In such case do one more + * pass to emit the final image. + */ + for (pass = 0; pass < 20 || image; pass++) { + proglen = do_jit(prog, addrs, image, oldproglen, &ctx); + if (proglen <= 0) { +out_image: + image = NULL; + if (header) + bpf_jit_binary_free(header); + prog = orig_prog; + goto out_addrs; + } + if (image) { + if (proglen != oldproglen) { + pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", + proglen, oldproglen); + goto out_image; + } + break; + } + if (proglen == oldproglen) { + header = bpf_jit_binary_alloc(proglen, &image, + 1, jit_fill_hole); + if (!header) { + prog = orig_prog; + goto out_addrs; + } + } + oldproglen = proglen; + cond_resched(); + } + + if (bpf_jit_enable > 1) + bpf_jit_dump(prog->len, proglen, pass + 1, image); + + if (image) { + bpf_jit_binary_lock_ro(header); + prog->bpf_func = (void *)image; + prog->jited = 1; + prog->jited_len = proglen; + } else { + prog = orig_prog; + } + +out_addrs: + kfree(addrs); +out: + if (tmp_blinded) + bpf_jit_prog_release_other(prog, prog == orig_prog ? + tmp : orig_prog); + return prog; +} |