On Wed, 2016-05-18 at 07:04 -0700, Davidlohr Bueso wrote: > On Tue, 17 May 2016, Waiman Long wrote: > > >Without using WRITE_ONCE(), the compiler can potentially break a > >write into multiple smaller ones (store tearing). So a read from the > >same data by another task concurrently may return a partial result. > >This can result in a kernel crash if the data is a memory address > >that is being dereferenced. > > > >This patch changes all write to rwsem->owner to use WRITE_ONCE() > >to make sure that store tearing will not happen. READ_ONCE() may > >not be needed for rwsem->owner as long as the value is only used for > >comparison and not dereferencing. > > > >Signed-off-by: Waiman Long <[email protected]> > > Yes, ->owner can obviously be handled locklessly during optimistic > spinning. > > Acked-by: Davidlohr Bueso <[email protected]>
Acked-by: Jason Low <[email protected]>
