From: Hou Tao <houtao1@huawei.com>
Date: Sat, 26 Feb 2022 12:19:05 +0000 (+0800)
Subject: bpf, arm64: Call build_prologue() first in first JIT pass
X-Git-Tag: howlett/maple/20220722_2~938^2~185^2~16
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=68e4f238b0e9d3670a1612ad900a6e98b2b3f7dd;p=users%2Fjedix%2Flinux-maple.git

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 74f9a9b6a0530..7152ee28facc2 100644
--- 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;
 	}