Re: [PATCH][BZ #13724] Do not segfault in pthread_setname_np (x, NULL)

["Carlos O'Donell" <carlos at redhat dot com>]

On 10/03/2013 08:20 AM, OndÅej BÃlka wrote:
> Hi, this is another bug that could be handled quickly. Problem is if 
> pthread_setname_np (x, NULL) should return error code or segfault. 
> (see https://sourceware.org/bugzilla/show_bug.cgi?id=13724 )
> If first is desired then following patch does it. If we choose for
> second then close that bugzilla entry.
> 
> 	* sysdeps/unix/sysv/linux/pthread_setname.c (pthread_setname_np):
> 	Handle null.
> 
> diff --git a/nptl/sysdeps/unix/sysv/linux/pthread_setname.c b/nptl/sysdeps/unix/sysv/linux/pthread_setname.c
> index d6455dd..45eefa0 100644
> --- a/nptl/sysdeps/unix/sysv/linux/pthread_setname.c
> +++ b/nptl/sysdeps/unix/sysv/linux/pthread_setname.c
> @@ -34,6 +34,10 @@ pthread_setname_np (th, name)
>  {
>    const struct pthread *pd = (const struct pthread *) th;
>  
> +  /* Return EFAULT like pthread_getname_np(x, NULL, 16) does.  */
> +  if (name == NULL)
> +    return EFAULT;
> +
>    /* Unfortunately the kernel headers do not export the TASK_COMM_LEN
>       macro.  So we have to define it here.  */
>  #define TASK_COMM_LEN 16
> 

Thanks for tackling the BZs. You're doing a great job here.

I agree with Jeff Law on this one, this is not a performance
critical routine and checking arguments and returning EFAULT
is good for QoI.

Could you please go one step further and add pthread_setname_np
to the manual? Add a @deftypefun in manual/threads.texi in the
"Non-POSIX Extensions" section and briefly describe the function.
See pthread_getattr_default_np/pthread_setattr_default_np as
exmaples.

OK with manual update.

Note: The manual has a typo and lists pthread_getattr_default_np
twice, the second instance should be pthread_setattr_default_np,
and a fix for that is obvious and can go in immediately.

Cheers,
Carlos.