1 files changed, 9 insertions, 17 deletions

diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index 73619d3aeb6c..2dc8b1484845 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -127,6 +127,9 @@ static void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx)
         PPC_BLR();
 }
 
+#define CHOOSE_LOAD_FUNC(K, func) \
+        ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
+
 /* Assemble the body code between the prologue & epilogue. */
 static int bpf_jit_build_body(struct sk_filter *fp, u32 *image,
                               struct codegen_context *ctx,
@@ -391,21 +394,16 @@ static int bpf_jit_build_body(struct sk_filter *fp, u32 *image,
 
                         /*** Absolute loads from packet header/data ***/
                 case BPF_S_LD_W_ABS:
-                        func = sk_load_word;
+                        func = CHOOSE_LOAD_FUNC(K, sk_load_word);
                         goto common_load;
                 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);
                 common_load:
-                        /*
-                         * Load from [K].  Reference with the (negative)
-                         * SKF_NET_OFF/SKF_LL_OFF offsets is unsupported.
-                         */
+                        /* Load from [K]. */
                         ctx->seen |= SEEN_DATAREF;
-                        if ((int)K < 0)
-                                return -ENOTSUPP;
                         PPC_LI64(r_scratch1, func);
                         PPC_MTLR(r_scratch1);
                         PPC_LI32(r_addr, K);
@@ -429,7 +427,7 @@ static int bpf_jit_build_body(struct sk_filter *fp, u32 *image,
                 common_load_ind:
                         /*
                          * Load from [X + K].  Negative offsets are tested for
-                         * in the helper functions, and result in a 'ret 0'.
+                         * in the helper functions.
                          */
                         ctx->seen |= SEEN_DATAREF | SEEN_XREG;
                         PPC_LI64(r_scratch1, func);
@@ -443,13 +441,7 @@ static int bpf_jit_build_body(struct sk_filter *fp, u32 *image,
                         break;
 
                 case BPF_S_LDX_B_MSH:
-                        /*
-                         * x86 version drops packet (RET 0) when K<0, whereas
-                         * interpreter does allow K<0 (__load_pointer, special
-                         * ancillary data).  common_load returns ENOTSUPP if K<0,
-                         * so we fall back to interpreter & filter works.
-                         */
-                        func = sk_load_byte_msh;
+                        func = CHOOSE_LOAD_FUNC(K, sk_load_byte_msh);
                         goto common_load;
                         break;