Re: [PATCH] Incorrect value for SIGRTMAX, MIPS nonsense removed, timer_gettime fix

[Andrew Morton <akpm@osdl.org>]

George Anzinger <george@mvista.com> wrote:
>
> The attached patch does the following:
> 
> Removes C++ comment in favor of C style.
> 
> Removes the special treatment for MIPS SIGEV values.  We only require (and error 
> if this fails) that the SIGEV_THREAD_ID value not share bits with the other 
> SIGEV values.  Note that mips has yet to define this value so when they do...
> 
> Corrects the check for the signal range to be from 1 to SIGRTMAX inclusive.
> 
> Adds a check to verify that kmem_cache_alloc() actually returned a timer, error 
> if not.
> 
> Fixes a bug in timer_gettime() where the incorrect value was returned if a 
> signal was pending on the timer OR the timer was a SIGEV_NONE timer.

> -	if ((event->sigev_notify & ~SIGEV_NONE & MIPS_SIGEV) &&
> -			event->sigev_signo &&
> -			((unsigned) (event->sigev_signo > SIGRTMAX)))
> +	if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
> +	    ((unsigned int) (event->sigev_signo - 1) >= SIGRTMAX))
>  		return NULL;

I was wondering if someone would try this one :( Really, this is just over
the top.  Take pity upon your readers, and do:

	if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
		(event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX))

> @@ -804,7 +826,7 @@
>  	 * equal to jiffies, so the timer notify function is called directly.
>  	 * We do not even queue SIGEV_NONE timers!
>  	 */
> -	if (!(timr->it_sigev_notify & SIGEV_NONE)) {
> +	if (!((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
>  		if (timr->it_timer.expires == jiffies)
>  			timer_notify_task(timr);
>  		else

Are you sure this is correct?   If so, using != would be clearer.