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SubjectRe: [RFC][PATCH 5/5] arch: Sanitize atomic_t bitwise ops
On Thu, Feb 06, 2014 at 09:56:54AM -0800, Linus Torvalds wrote:
> On Thu, Feb 6, 2014 at 9:52 AM, Peter Zijlstra <peterz@infradead.org> wrote:
> It's the "_return" variants. As far as I can tell, there are exactly
> ZERO users of that stuff, and they are BAD BAD BAD.
>
> On x86, those things would cause a cmpxchg loop, and the bad
> read-for-shared-before-acquire cacheline pattern.
>
> So why indirectly encourage people to add users for a bad operation?

OK, I'll not generate the _return() variants.


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