powerpc/bpf: Fix tail call implementation

[sfrench/cifs-2.6.git] / arch / powerpc / net / bpf_jit_comp64.c

diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 02a59946a78af46416e9d949047ad3fefe3fc159..be3517ef0574d0911f6d63b530b33954c8ca343d 100644 (file)
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -1141,6 +1141,19 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
                goto out_addrs;
        }
 
+       /*
+        * If we have seen a tail call, we need a second pass.
+        * This is because bpf_jit_emit_common_epilogue() is called
+        * from bpf_jit_emit_tail_call() with a not yet stable ctx->seen.
+        */
+       if (cgctx.seen & SEEN_TAILCALL) {
+               cgctx.idx = 0;
+               if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) {
+                       fp = org_fp;
+                       goto out_addrs;
+               }
+       }
+
        /*
         * Pretend to build prologue, given the features we've seen.  This will
         * update ctgtx.idx as it pretends to output instructions, then we can