Re: [PATCH v2 1/2] tracing/hist: rebuild full_name on each hist_field_name() call

Steven Rostedt
2026-03-30T14:21:22Z

On Mon, 30 Mar 2026 10:46:19 +0800
Pengpeng Hou <pengpeng@iscas.ac.cn> wrote:

Please resend both patches as a separate thread series. Do not send new
versions of the patch as a reply to the old one. That just makes it much
harder for maintainers to keep track of patches, as they are hidden within
threads.

> hist_field_name() uses a static MAX_FILTER_STR_VAL buffer for fully
> qualified variable-reference names, but it currently appends into that
> buffer with strcat() without rebuilding it first. As a result, repeated
> calls append a new "system.event.field" name onto the previous one,
> which can eventually run past the end of full_name.
>
> Build the name with snprintf() on each call and return NULL if the fully
> qualified name does not fit in MAX_FILTER_STR_VAL.
>
> Fixes: 067fe038e70f ("tracing: Add variable reference handling to hist triggers")
> Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
> ---
> v2:

Instead of saying "v2", use:

Changes since v1: https://lore.kernel.org/all/20260329030950.32503-1-pengpeng@iscas.ac.cn/

That keeps the history link of this patch compared to the previous version.

-- Steve

> - rebuild full_name on each call instead of falling back to field->name
> - return NULL on overflow as suggested
> - split out the snprintf() length check instead of using an inline if