bpf, arm64: Call build_prologue() first in first JIT pass

BPF line info needs ctx->offset to be the instruction offset in the whole JITed
image instead of the body itself, so also call build_prologue() first in first
JIT pass.

Fixes: 37ab566c178d ("bpf: arm64: Enable arm64 jit to provide bpf_line_info")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220226121906.5709-2-houtao1@huawei.com

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 74f9a9b..7152ee2 100644 (file)
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -1049,15 +1049,18 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
                goto out_off;
        }
 
-       /* 1. Initial fake pass to compute ctx->idx. */
-
-       /* Fake pass to fill in ctx->offset. */
-       if (build_body(&ctx, extra_pass)) {
+       /*
+        * 1. Initial fake pass to compute ctx->idx and ctx->offset.
+        *
+        * BPF line info needs ctx->offset[i] to be the offset of
+        * instruction[i] in jited image, so build prologue first.
+        */
+       if (build_prologue(&ctx, was_classic)) {
                prog = orig_prog;
                goto out_off;
        }
 
-       if (build_prologue(&ctx, was_classic)) {
+       if (build_body(&ctx, extra_pass)) {
                prog = orig_prog;
                goto out_off;
        }