[PATCH 5.16 0553/1017] bpf, arm64: Call build_prologue() first in first JIT pass

Greg Kroah-Hartman
2022-04-05T09:53:12Z

From: Hou Tao <houtao1@huawei.com>

[ Upstream commit 68e4f238b0e9d3670a1612ad900a6e98b2b3f7dd ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm64/net/bpf_jit_comp.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 71ef9dcd9b57..3c6d0d60820f 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;
}
--
2.34.1