Re: [PATCH 3/5] asm-generic, kcsan: Add KCSAN instrumentation for bitops

[Paul E. McKenney]

On Mon, Jan 20, 2020 at 03:40:48PM +0100, Peter Zijlstra wrote:
> On Mon, Jan 20, 2020 at 03:19:25PM +0100, Marco Elver wrote:
> > Add explicit KCSAN checks for bitops.
> > 
> > Note that test_bit() is an atomic bitop, and we instrument it as such,
> 
> Well, it is 'atomic' in the same way that atomic_read() is. Both are
> very much not atomic ops, but are part of an interface that facilitates
> atomic operations.

True, but they all are either inline assembly or have either an
implicit or explicit cast to volatile, so they could be treated
the same as atomic_read(), correct?  If not, what am I missing?

(There is one exception, but it is in arch/x86/boot/bitops.h,
which I UP-only, correct?)

						Thanx, Paul