Re: [RFC PATCH 01/15] cmpxchg_local() is not signed-value safe, so fix generic atomics

[Arnd Bergmann]

On Wednesday 18 May 2016 16:10:45 David Howells wrote:
> cmpxchg_local() is not signed-value safe because on a 64-bit machine signed
> int arguments to it may be sign-extended to signed long _before_ begin cast
> to unsigned long.  This potentially causes comparisons to fail when dealing
> with negative values.
> 
> Fix the generic atomic functions that are implemented in terms of cmpxchg()
> to cast their arguments to unsigned int before calling cmpxchg().
> 
> Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
> 

Isn't the problem you describe something that cmpxchg() could prevent instead?

	Arnd