diff options
Diffstat (limited to 'arch/x86/net/bpf_jit_comp.c')
| -rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 43 |
1 files changed, 25 insertions, 18 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 5671752..0597f95 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -30,7 +30,10 @@ int bpf_jit_enable __read_mostly; * assembly code in arch/x86/net/bpf_jit.S */ extern u8 sk_load_word[], sk_load_half[], sk_load_byte[], sk_load_byte_msh[]; -extern u8 sk_load_word_ind[], sk_load_half_ind[], sk_load_byte_ind[]; +extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[]; +extern u8 sk_load_byte_positive_offset[], sk_load_byte_msh_positive_offset[]; +extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[]; +extern u8 sk_load_byte_negative_offset[], sk_load_byte_msh_negative_offset[]; static inline u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) { @@ -117,6 +120,8 @@ static inline void bpf_flush_icache(void *start, void *end) set_fs(old_fs); } +#define CHOOSE_LOAD_FUNC(K, func) \ + ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) void bpf_jit_compile(struct sk_filter *fp) { @@ -289,7 +294,7 @@ void bpf_jit_compile(struct sk_filter *fp) EMIT2(0x24, K & 0xFF); /* and imm8,%al */ } else if (K >= 0xFFFF0000) { EMIT2(0x66, 0x25); /* and imm16,%ax */ - EMIT2(K, 2); + EMIT(K, 2); } else { EMIT1_off32(0x25, K); /* and imm32,%eax */ } @@ -473,44 +478,46 @@ void bpf_jit_compile(struct sk_filter *fp) #endif break; case BPF_S_LD_W_ABS: - func = sk_load_word; + func = CHOOSE_LOAD_FUNC(K, sk_load_word); common_load: seen |= SEEN_DATAREF; - if ((int)K < 0) { - /* Abort the JIT because __load_pointer() is needed. */ - goto out; - } t_offset = func - (image + addrs[i]); EMIT1_off32(0xbe, K); /* mov imm32,%esi */ EMIT1_off32(0xe8, t_offset); /* call */ break; case BPF_S_LD_H_ABS: - func = sk_load_half; + func = CHOOSE_LOAD_FUNC(K, sk_load_half); goto common_load; case BPF_S_LD_B_ABS: - func = sk_load_byte; + func = CHOOSE_LOAD_FUNC(K, sk_load_byte); goto common_load; case BPF_S_LDX_B_MSH: - if ((int)K < 0) { - /* Abort the JIT because __load_pointer() is needed. */ - goto out; - } + func = CHOOSE_LOAD_FUNC(K, sk_load_byte_msh); seen |= SEEN_DATAREF | SEEN_XREG; - t_offset = sk_load_byte_msh - (image + addrs[i]); + t_offset = func - (image + addrs[i]); EMIT1_off32(0xbe, K); /* mov imm32,%esi */ EMIT1_off32(0xe8, t_offset); /* call sk_load_byte_msh */ break; case BPF_S_LD_W_IND: - func = sk_load_word_ind; + func = sk_load_word; common_load_ind: seen |= SEEN_DATAREF | SEEN_XREG; t_offset = func - (image + addrs[i]); - EMIT1_off32(0xbe, K); /* mov imm32,%esi */ + if (K) { + if (is_imm8(K)) { + EMIT3(0x8d, 0x73, K); /* lea imm8(%rbx), %esi */ + } else { + EMIT2(0x8d, 0xb3); /* lea imm32(%rbx),%esi */ + EMIT(K, 4); + } + } else { + EMIT2(0x89,0xde); /* mov %ebx,%esi */ + } EMIT1_off32(0xe8, t_offset); /* call sk_load_xxx_ind */ break; case BPF_S_LD_H_IND: - func = sk_load_half_ind; + func = sk_load_half; goto common_load_ind; case BPF_S_LD_B_IND: - func = sk_load_byte_ind; + func = sk_load_byte; goto common_load_ind; case BPF_S_JMP_JA: t_offset = addrs[i + K] - addrs[i]; |
