Re: [PATCH] make atomic_t volatile on all architectures

[Linus Torvalds <torvalds@linux-foundation.org>]

On Sun, 12 Aug 2007, Segher Boessenkool wrote:
> 
> Yeah.  Compiler errors are more annoying though I dare say ;-)

Actually, compile-time errors are fine, and easy to work around. *Much* 
more annoying is when gcc actively generates subtly bad code. We've had 
use-after-free issues due to incorrect gcc liveness calculations etc, and 
inline asm has beeen one of the more common causes - exactly because the 
kernel is one of the few users (along with glibc) that uses it at all.

Now *those* are hard to find - the code works most of the time, but the 
compiler has inserted a really subtle race condition into the code 
(deallocated a local stack entry before last use). We had that with our 
semaphore code at some point.

		Linus