On Wed, May 06, 2020 at 02:33:33PM +0100, Will Deacon wrote: > On Tue, May 05, 2020 at 03:16:08PM +0200, Thomas Gleixner wrote: > > READ/WRITE_ONCE_NOCHECK() is required for atomics in code which cannot be > > instrumented like the x86 int3 text poke code. As READ/WRITE_ONCE() is > > undergoing a rewrite, provide __{READ,WRITE}_ONCE_SCALAR(). > > > > Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> > > Signed-off-by: Thomas Gleixner <t...@linutronix.de> > > --- > > include/linux/compiler.h | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > --- a/include/linux/compiler.h > > +++ b/include/linux/compiler.h > > @@ -313,6 +313,14 @@ unsigned long read_word_at_a_time(const > > __u.__val; \ > > }) > > > > +#define __READ_ONCE_SCALAR(x) \ > > + (*(const volatile typeof(x) *)&(x)) > > + > > +#define __WRITE_ONCE_SCALAR(x, val) \ > > +do { \ > > + *(volatile typeof(x) *)&(x) = val; \ > > +} while (0) > > FWIW, these end up being called __READ_ONCE() and __WRITE_ONCE() after > the rewrite; the *_SCALAR() variants will call into kcsan_check_atomic_*(). > > If you go with that naming now, then any later conflict should fall out in > the wash.
Ah excellent, clearly we had slightly different resoltions vs kcsan. Thanks!