bpf/btf: Fix is_int_ptr()

[ Upstream commit 91f2dc6838 ]

When tracing a kernel function with arg type is u32*, btf_ctx_access()
would report error: arg2 type INT is not a struct.

The commit bb6728d756 ("bpf: Allow access to int pointer arguments
in tracing programs") added support for int pointer, but did not skip
modifiers before checking it's type. This patch fixes it.

Fixes: bb6728d756 ("bpf: Allow access to int pointer arguments in tracing programs")
Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20230410085908.98493-2-zhoufeng.zf@bytedance.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Feng Zhou 2023-04-10 16:59:07 +08:00 committed by Greg Kroah-Hartman
parent 1f1267ce0b
commit 52c3d68d99

View file

@ -5333,12 +5333,8 @@ struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog)
static bool is_int_ptr(struct btf *btf, const struct btf_type *t)
{
/* t comes in already as a pointer */
t = btf_type_by_id(btf, t->type);
/* allow const */
if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST)
t = btf_type_by_id(btf, t->type);
/* skip modifiers */
t = btf_type_skip_modifiers(btf, t->type, NULL);
return btf_type_is_int(t);
}