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];