Re: [PATCH v2 3/6] tracing: Use copy_from_user_nul() instead of copy_from_user()
From: Yury Norov <hidden>
Date: 2026-01-13 17:05:20
Also in:
lkml
On Mon, Jan 12, 2026 at 03:30:36PM +0800, Fushuai Wang wrote:
quoted hunk ↗ jump to hunk
From: Fushuai Wang <redacted> Use copy_from_user_nul() instead of copy_from_user() to simplify the code. No functional change. Signed-off-by: Fushuai Wang <redacted> --- 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