[PATCH v4 06/11] seq_buf: Add seq_buf_terminate()

[sashiko-bot at kernel.org]

> Seven callers call seq_buf_str() only to NUL-terminate the buffer,
> discarding the returned pointer. Two of them need a comment to say so.
> 
> Add seq_buf_terminate(), wrapping the __seq_buf_terminate() helper that
> seq_buf_str() and seq_buf_strlen() already use, and convert those
> callers. It returns void: returning the offset would just be
> seq_buf_strlen() under another name. A zero-sized seq_buf is left
> untouched, as in the other accessors.
> 
> Add tests for the three cases: room for the NUL after the data, an
> overflowed buffer where it lands in the last byte, and a zero-sized
> buffer that must not be written to.
> 
> Build tested ARCH=x86_64 defconfig with GCC 16.2.0, plus
> CONFIG_HIST_TRIGGERS=y and CONFIG_BPF_SYSCALL=y to reach the converted
> call sites in kernel/trace/trace_events_hist.c and
> kernel/bpf/diagnostics.c. Tests run 24/24 passing on ARCH=um.
> 
> Assisted-by: LLM
> Signed-off-by: Kees Cook <kees at kernel.org>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20261003035906.too.263-kees@kernel.org?part=6