From 91f2dc6838c19342f7f2993627c622835cc24890 Mon Sep 17 00:00:00 2001 From: Feng Zhou Date: Mon, 10 Apr 2023 16:59:07 +0800 Subject: [PATCH] bpf/btf: Fix is_int_ptr() 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 Signed-off-by: Chengming Zhou Signed-off-by: Feng Zhou Signed-off-by: Daniel Borkmann Acked-by: Jiri Olsa Link: https://lore.kernel.org/bpf/20230410085908.98493-2-zhoufeng.zf@bytedance.com --- 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 ffc31a1..913b9d71 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -5921,12 +5921,8 @@ 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); } -- 2.7.4