This is a note to let you know that I've just added the patch titled
bpf/btf: Fix is_int_ptr()
to the 6.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bpf-btf-fix-is_int_ptr.patch
and it can be found in the queue-6.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cea72040945a935b4e67534c29655064b13cc2d3
Author: Feng Zhou <zhoufeng.zf@xxxxxxxxxxxxx>
Date: Mon Apr 10 16:59:07 2023 +0800
bpf/btf: Fix is_int_ptr()
[ 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@xxxxxxxxxxxxx>
Signed-off-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
Signed-off-by: Feng Zhou <zhoufeng.zf@xxxxxxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20230410085908.98493-2-zhoufeng.zf@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 73780748404c2..3140a7881665d 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -5891,12 +5891,8 @@ 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);
}
