From: Feng Zhou zhoufeng.zf@bytedance.com
[ Upstream commit 91f2dc6838c19342f7f2993627c622835cc24890 ]
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 bb6728d75611 ("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: bb6728d75611 ("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 --- kernel/bpf/btf.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 70ab572f81bc7..7f18d48c4a15b 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -5848,12 +5848,8 @@ 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); }