On Mon, Jan 12, 2026 at 03:30:36PM +0800, Fushuai Wang wrote:
> From: Fushuai Wang <[email protected]>
>
> Use copy_from_user_nul() instead of copy_from_user() to simplify
> the code.
>
> No functional change.
>
> Signed-off-by: Fushuai Wang <[email protected]>
> ---
> kernel/trace/trace.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index baec63134ab6..b6ffd006fcf9 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -11266,10 +11266,9 @@ ssize_t trace_parse_run_command(struct file *file,
> const char __user *buffer,
> if (size >= WRITE_BUFSIZE)
> size = WRITE_BUFSIZE - 1;
>
> - if (copy_from_user(kbuf, buffer + done, size))
> + if (copy_from_user_nul(kbuf, buffer + done, size))
> return -EFAULT;
This hides the original error. Can you switch it to:
err = copy_xxx();
if (err)
return err;
I understand that in this case EFAULT is the only possible error, but
the above pattern is really error-prone, and is reproduced again and
again over the kernel.
> - kbuf[size] = '\0';
> buf = kbuf;
> do {
> tmp = strchr(buf, '\n');
> --
> 2.36.1
