[PATCH 5.17 0611/1126] bpf, arm64: Feed byte-offset into bpf line info

Greg Kroah-Hartman
2022-04-05T10:08:29Z

From: Hou Tao <houtao1@huawei.com>

[ Upstream commit dda7596c109fc382876118627e29db7607cde35d ]

insn_to_jit_off passed to bpf_prog_fill_jited_linfo() is calculated in
instruction granularity instead of bytes granularity, but BPF line info
requires byte offset.

bpf_prog_fill_jited_linfo() will be the last user of ctx.offset before
it is freed, so convert the offset into byte-offset before calling into
bpf_prog_fill_jited_linfo() in order to fix the line info dump on arm64.

Fixes: 37ab566c178d ("bpf: arm64: Enable arm64 jit to provide bpf_line_info")
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220226121906.5709-3-houtao1@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm64/net/bpf_jit_comp.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 6a83f3070985..cbc41e261f1e 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -1133,6 +1133,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
prog->jited_len = prog_size;

if (!prog->is_func || extra_pass) {
+ int i;
+
+ /* offset[prog->len] is the size of program */
+ for (i = 0; i <= prog->len; i++)
+ ctx.offset[i] *= AARCH64_INSN_SIZE;
bpf_prog_fill_jited_linfo(prog, ctx.offset + 1);
out_off:
kfree(ctx.offset);
--
2.34.1