Re: [PATCH 03/11] kthread: Pass in the thread's name during creation

Christian Brauner
2023-03-11T08:53:41Z

On Fri, Mar 10, 2023 at 04:03:24PM -0600, Mike Christie wrote:
> This has us pass in the thread's name during creation in kernel_thread.
>
> Signed-off-by: Mike Christie <michael.christie@oracle.com>
> ---
> kernel/kthread.c | 35 ++++++++++++++---------------------
> 1 file changed, 14 insertions(+), 21 deletions(-)
>
> diff --git a/kernel/kthread.c b/kernel/kthread.c
> index 63574cee925e..831a55b406d8 100644
> --- a/kernel/kthread.c
> +++ b/kernel/kthread.c
> @@ -38,6 +38,7 @@ struct task_struct *kthreadd_task;
> struct kthread_create_info
> {
> /* Information passed to kthread() from kthreadd. */
> + char *full_name;
> int (*threadfn)(void *data);
> void *data;
> int node;
> @@ -343,10 +344,15 @@ static int kthread(void *_create)
> /* Release the structure when caller killed by a fatal signal. */
> done = xchg(&create->done, NULL);
> if (!done) {
> + kfree(create->full_name);
> kfree(create);
> kthread_exit(-EINTR);
> }
>
> + if (strlen(create->full_name) >= TASK_COMM_LEN)
> + self->full_name = create->full_name;
> + else
> + kfree(create->full_name);

This is monir but wwiw, this looks suspicious when reading it without
more context. It took me a while to see that kthread->full_name is
intended to store the untruncated name only if truncation actually needs
to happen. So either we should always initialize this or we should add a
comment. You can just send a tiny patch that I can fold into this one so
you don't have to resend the whole series...