diff options
| -rw-r--r-- | arch/x86/net/bpf_jit_comp32.c | 236 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/jit.c | 19 |
2 files changed, 191 insertions, 64 deletions
diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c index 0d9cdffce6ac..b29e82f190c7 100644 --- a/arch/x86/net/bpf_jit_comp32.c +++ b/arch/x86/net/bpf_jit_comp32.c @@ -117,6 +117,8 @@ static bool is_simm32(s64 value) #define IA32_JLE 0x7E #define IA32_JG 0x7F +#define COND_JMP_OPCODE_INVALID (0xFF) + /* * Map eBPF registers to IA32 32bit registers or stack scratch space. * @@ -698,19 +700,12 @@ static inline void emit_ia32_neg64(const u8 dst[], bool dstk, u8 **pprog) 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)); + /* neg dreg_lo */ + EMIT2(0xF7, add_1reg(0xD8, dreg_lo)); + /* adc dreg_hi,0x0 */ + EMIT3(0x83, add_1reg(0xD0, dreg_hi), 0x00); + /* neg dreg_hi */ + EMIT2(0xF7, add_1reg(0xD8, dreg_hi)); if (dstk) { /* mov dword ptr [ebp+off],dreg_lo */ @@ -1613,6 +1608,75 @@ static inline void emit_push_r64(const u8 src[], u8 **pprog) *pprog = prog; } +static u8 get_cond_jmp_opcode(const u8 op, bool is_cmp_lo) +{ + u8 jmp_cond; + + /* Convert BPF opcode to x86 */ + switch (op) { + 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: + if (!is_cmp_lo) + /* Signed '>', GT in x86 */ + jmp_cond = IA32_JG; + else + /* GT is unsigned '>', JA in x86 */ + jmp_cond = IA32_JA; + break; + case BPF_JSLT: + if (!is_cmp_lo) + /* Signed '<', LT in x86 */ + jmp_cond = IA32_JL; + else + /* LT is unsigned '<', JB in x86 */ + jmp_cond = IA32_JB; + break; + case BPF_JSGE: + if (!is_cmp_lo) + /* Signed '>=', GE in x86 */ + jmp_cond = IA32_JGE; + else + /* GE is unsigned '>=', JAE in x86 */ + jmp_cond = IA32_JAE; + break; + case BPF_JSLE: + if (!is_cmp_lo) + /* Signed '<=', LE in x86 */ + jmp_cond = IA32_JLE; + else + /* LE is unsigned '<=', JBE in x86 */ + jmp_cond = IA32_JBE; + break; + default: /* to silence GCC warning */ + jmp_cond = COND_JMP_OPCODE_INVALID; + break; + } + + return jmp_cond; +} + static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, int oldproglen, struct jit_context *ctx) { @@ -2069,10 +2133,6 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, 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: case BPF_JMP32 | BPF_JEQ | BPF_X: case BPF_JMP32 | BPF_JNE | BPF_X: case BPF_JMP32 | BPF_JGT | BPF_X: @@ -2118,6 +2178,40 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, EMIT2(0x39, add_2reg(0xC0, dreg_lo, sreg_lo)); goto emit_cond_jmp; } + 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, 10); + /* cmp dreg_lo,sreg_lo */ + EMIT2(0x39, add_2reg(0xC0, dreg_lo, sreg_lo)); + goto emit_cond_jmp_signed; + } case BPF_JMP | BPF_JSET | BPF_X: case BPF_JMP32 | BPF_JSET | BPF_X: { bool is_jmp64 = BPF_CLASS(insn->code) == BPF_JMP; @@ -2194,10 +2288,6 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, 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: case BPF_JMP32 | BPF_JEQ | BPF_K: case BPF_JMP32 | BPF_JNE | BPF_K: case BPF_JMP32 | BPF_JGT | BPF_K: @@ -2238,50 +2328,9 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, /* 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 */ +emit_cond_jmp: jmp_cond = get_cond_jmp_opcode(BPF_OP(code), false); + if (jmp_cond == COND_JMP_OPCODE_INVALID) return -EFAULT; - } jmp_offset = addrs[i + insn->off] - addrs[i]; if (is_imm8(jmp_offset)) { EMIT2(jmp_cond, jmp_offset); @@ -2291,7 +2340,66 @@ emit_cond_jmp: /* Convert BPF opcode to x86 */ pr_err("cond_jmp gen bug %llx\n", jmp_offset); return -EFAULT; } + break; + } + 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: { + 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; + u32 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)); + } + + /* mov ecx,imm32 */ + EMIT2_off32(0xC7, add_1reg(0xC0, IA32_ECX), imm32); + hi = imm32 & (1 << 31) ? (u32)~0 : 0; + /* 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, 10); + /* cmp dreg_lo,sreg_lo */ + EMIT2(0x39, add_2reg(0xC0, dreg_lo, sreg_lo)); + + /* + * For simplicity of branch offset computation, + * let's use fixed jump coding here. + */ +emit_cond_jmp_signed: /* Check the condition for low 32-bit comparison */ + jmp_cond = get_cond_jmp_opcode(BPF_OP(code), true); + if (jmp_cond == COND_JMP_OPCODE_INVALID) + return -EFAULT; + jmp_offset = addrs[i + insn->off] - addrs[i] + 8; + 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; + } + EMIT2(0xEB, 6); + + /* Check the condition for high 32-bit comparison */ + jmp_cond = get_cond_jmp_opcode(BPF_OP(code), false); + if (jmp_cond == COND_JMP_OPCODE_INVALID) + return -EFAULT; + jmp_offset = addrs[i + insn->off] - addrs[i]; + 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: diff --git a/tools/testing/selftests/bpf/verifier/jit.c b/tools/testing/selftests/bpf/verifier/jit.c index be488b4495a3..c33adf344fae 100644 --- a/tools/testing/selftests/bpf/verifier/jit.c +++ b/tools/testing/selftests/bpf/verifier/jit.c @@ -86,3 +86,22 @@ .result = ACCEPT, .retval = 2, }, +{ + "jit: jsgt, jslt", + .insns = { + BPF_LD_IMM64(BPF_REG_1, 0x80000000ULL), + BPF_LD_IMM64(BPF_REG_2, 0x0ULL), + BPF_JMP_REG(BPF_JSGT, BPF_REG_1, BPF_REG_2, 2), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + + BPF_JMP_REG(BPF_JSLT, BPF_REG_2, BPF_REG_1, 2), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + + BPF_MOV64_IMM(BPF_REG_0, 2), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 2, +}, |