On Wed, Jan 03, 2024 at 05:14:19PM +0800, peterx@xxxxxxxxxx wrote: > From: Peter Xu <peterx@xxxxxxxxxx> > > Introduce "pud_t pud" in the function, so the code won't dereference *pudp > multiple time. Not only because that looks less straightforward, but also > because if the dereference really happened, it's not clear whether there > can be race to see different *pudp values if it's being modified at the > same time. > > Acked-by: James Houghton <jthoughton@xxxxxxxxxx> > Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> > --- > mm/gup.c | 17 +++++++++-------- > 1 file changed, 9 insertions(+), 8 deletions(-) I think we have several more case like this, and I ceratinly agree code should not access a READ_ONCE variable more than once :( Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Jason
