Re: [PATCH 1/2] tracing/probes: Fix anon_stack check for unnamed bitfields in btf_find_struct_member

[Steven Rostedt]

On Tue,  1 Sep 2026 00:06:05 +0900
"Masami Hiramatsu (Google)" <mhiramat@xxxxxxxxxx> wrote:

> From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
> 
> btf_find_struct_member() traverses into nested anonymous structures
> and unions by pushing members with !member->name_off onto anon_stack.
> However, it does not consider the unnamed bitfields (e.g. `int : 5`
> or `unsigned int : 0`) which also have member->name_off == 0.
> 
> If such an unnamed bitfield is pushed to anon_stack, the
> btf_find_struct_member() return an error even if there are other
> valid entries in anon_stack.
> 
> To fix this, only push unnamed struct/union members to anon_stack.
> Also move the btf_type_is_struct() check to the entry of this function
> because now it is sure only struct/union are pushed to anon_stack.
> 

Should we add Reported-by and a link to the Sashiko report?

> Fixes: 302db0f5b3d8 ("tracing/probes: Add a function to search a member of a struct/union")
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>

Reviewed-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

-- Steve