Re: [KJ] (re) audit return code handling for kernel_thread [1/3]

[Andrew Morton <akpm@osdl.org>]

On Sat, 29 Jul 2006 16:15:55 -0400
Neil Horman <nhorman@tuxdriver.com> wrote:

> Patch to audit return code checking of kernel_thread.  These fixes correct those
> callers who fail to check the return code of kernel_thread at all
> 
> 

Various people are running around converting open-coded kernel_thread
callers over to the kthread API.  Generally that's a good thing, and error
checking should be incorporated at that time.

So there's probably not a lot of point in making these changes now - it'd
be better to work with the various subsystem owners on doing the kthread
conversion.

> --- a/arch/s390/mm/cmm.c
> +++ b/arch/s390/mm/cmm.c
> @@ -161,7 +161,11 @@ cmm_thread(void *dummy)
>  static void
>  cmm_start_thread(void)
>  {
> -	kernel_thread(cmm_thread, NULL, 0);
> +	if (kernel_thread(cmm_thread, NULL, 0) < 0) {
> +		printk(KERN_WARNING "Could not start kernel thread at %s:%d\n",
> +			__FUNCTION__,__LINE__);
> +		clear_bit(0,&cmm_thread_active);
> +	}
>  }

This is OK as far as it goes.  But really we should propagate any failure
back up to cmm_init() and fail the whole thing, rather than leaving the
driver hanging around in a loaded-but-useless state.