Re: [PATCH v3 2/2] tracing: Bound histogram expression strings with seq_buf

[Steven Rostedt <rostedt@goodmis.org>]

On Fri, 17 Apr 2026 20:28:00 +0800
Pengpeng Hou <pengpeng@iscas.ac.cn> wrote:

> expr_str() allocates a fixed MAX_FILTER_STR_VAL buffer and then builds
> expression names with a series of raw strcat() appends. Nested operands,
> constants and field flags can push the rendered string past that fixed
> limit before the name is attached to the hist field.
> 
> Build the expression strings with seq_buf and return -E2BIG when the
> rendered name would exceed MAX_FILTER_STR_VAL.
> 
> Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
> ---

Things have changed and this no longer applies cleanly. Can you send a v3
rebased on top of v7.1-rc3.

Also, make sure it's a new thread and not a reply to this patch series.

You can add a

 Changes since v3: https://lore.kernel.org/all/20260417223002.2-tracing-expr-v3-pengpeng@iscas.ac.cn/

to that patch too.

-- Steve


> Changes since v2:
> - split the ERR_PTR() conversion into patch 1/2 as requested by Steven
>   Rostedt
> - keep this patch focused on the seq_buf conversion and overflow
>   detection
>