> -----Original Message----- > From: Jens Axboe <axboe@xxxxxxxxx> > Sent: Saturday, January 25, 2025 5:35 AM > To: io-uring <io-uring@xxxxxxxxxxxxxxx> > Subject: [PATCH] io_uring/register: use atomic_read/write for sq_flags > migration > > A previous commit changed all of the migration from the old to the new ring > for resizing to use READ/WRITE_ONCE. However, ->sq_flags is an atomic_t, and > while most archs won't complain on this, some will indeed flag this: > > io_uring/register.c:554:9: sparse: sparse: cast to non-scalar > io_uring/register.c:554:9: sparse: sparse: cast from non-scalar > > Just use atomic_set/atomic_read for handling this case. > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > Closes: https://lore.kernel.org/oe-kbuild-all/202501242000.A2sKqaCL- > lkp@xxxxxxxxx/ > Fixes: 2c5aae129f42 ("io_uring/register: document io_register_resize_rings() > shared mem usage") > Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> > > --- > > diff --git a/io_uring/register.c b/io_uring/register.c index > 0db181437ae3..9a4d2fbce4ae 100644 > --- a/io_uring/register.c > +++ b/io_uring/register.c > @@ -552,7 +552,7 @@ static int io_register_resize_rings(struct io_ring_ctx > *ctx, void __user *arg) > ctx->cqe_cached = ctx->cqe_sentinel = NULL; > > WRITE_ONCE(n.rings->sq_dropped, READ_ONCE(o.rings- > >sq_dropped)); > - WRITE_ONCE(n.rings->sq_flags, READ_ONCE(o.rings->sq_flags)); > + atomic_set(&n.rings->sq_flags, atomic_read(&o.rings->sq_flags)); > WRITE_ONCE(n.rings->cq_flags, READ_ONCE(o.rings->cq_flags)); > WRITE_ONCE(n.rings->cq_overflow, READ_ONCE(o.rings- > >cq_overflow)); > > -- > Jens Axboe > Reviewed-by: Li Zetao <lizetao1@xxxxxxxxxx> -- Li Zetao
