Re: [PATCH v7 3/3] x86/refcount: Implement fast refcount overflow protection

2017-07-24 Thread Kees Cook
On Mon, Jul 24, 2017 at 2:07 AM, Ingo Molnar wrote: > > * Kees Cook wrote: > >> +config ARCH_HAS_REFCOUNT >> + bool >> + help >> + An architecture selects this when it has implemented refcount_t >> + using primitizes that provide a

Re: [PATCH v7 3/3] x86/refcount: Implement fast refcount overflow protection

2017-07-24 Thread Kees Cook
On Mon, Jul 24, 2017 at 2:07 AM, Ingo Molnar wrote: > > * Kees Cook wrote: > >> +config ARCH_HAS_REFCOUNT >> + bool >> + help >> + An architecture selects this when it has implemented refcount_t >> + using primitizes that provide a faster runtime at the expense >> + of

Re: [PATCH v7 3/3] x86/refcount: Implement fast refcount overflow protection

2017-07-24 Thread Ingo Molnar
* Kees Cook wrote: > +config ARCH_HAS_REFCOUNT > + bool > + help > + An architecture selects this when it has implemented refcount_t > + using primitizes that provide a faster runtime at the expense > + of some full refcount state checks. The

Re: [PATCH v7 3/3] x86/refcount: Implement fast refcount overflow protection

2017-07-24 Thread Ingo Molnar
* Kees Cook wrote: > +config ARCH_HAS_REFCOUNT > + bool > + help > + An architecture selects this when it has implemented refcount_t > + using primitizes that provide a faster runtime at the expense > + of some full refcount state checks. The refcount overflow

[PATCH v7 3/3] x86/refcount: Implement fast refcount overflow protection

2017-07-23 Thread Kees Cook
This implements refcount_t overflow protection on x86 without a noticeable performance impact, though without the fuller checking of REFCOUNT_FULL. This is done by duplicating the existing atomic_t refcount implementation but with normally a single instruction added to detect if the refcount has

[PATCH v7 3/3] x86/refcount: Implement fast refcount overflow protection

2017-07-23 Thread Kees Cook
This implements refcount_t overflow protection on x86 without a noticeable performance impact, though without the fuller checking of REFCOUNT_FULL. This is done by duplicating the existing atomic_t refcount implementation but with normally a single instruction added to detect if the refcount has