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path: root/arch/x86/net/bpf_jit_comp.c
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Diffstat (limited to 'arch/x86/net/bpf_jit_comp.c')
-rw-r--r--arch/x86/net/bpf_jit_comp.c41
1 files changed, 24 insertions, 17 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 5a5b6e4dd738..0597f95b6da6 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)
{
@@ -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];