[PATCH bpf-next v4 2/2] bpf, arm64: feed byte-offset into bpf line info

[Hou Tao]

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
its free, so convert the offset into byte-offset before call
bpf_prog_fill_jited_linfo().

Fixes: 37ab566c178d ("bpf: arm64: Enable arm64 jit to provide bpf_line_info")
Suggested-by: Daniel Borkmann <daniel at iogearbox.net>
Signed-off-by: Hou Tao <houtao1 at huawei.com>
---
 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 68b35c83e637..e850c69e128c 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -1274,6 +1274,11 @@ 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);
-- 
2.18.2