Re: [Linaro-mm-sig] [PATCH] dma-buf/sw-sync: don't enable IRQ from sync_print_obj()

[Christian König]

Am 24.05.24 um 15:26 schrieb Tetsuo Handa:
> On 2024/05/07 22:09, Christian König wrote:
> > Am 05.05.24 um 16:08 schrieb Tetsuo Handa:
> > > Since commit a6aa8fca4d79 ("dma-buf/sw-sync: Reduce irqsave/irqrestore from
> > > known context") by error replaced spin_unlock_irqrestore() with
> > > spin_unlock_irq() for both sync_debugfs_show() and sync_print_obj() despite
> > > sync_print_obj() is called from sync_debugfs_show(), lockdep complains
> > > inconsistent lock state warning.
> > >
> > > Use plain spin_{lock,unlock}() for sync_print_obj(), for
> > > sync_debugfs_show() is already using spin_{lock,unlock}_irq().
> > >
> > > Reported-by: syzbot <syzbot+a225ee3df7e7f9372dbe@xxxxxxxxxxxxxxxxxxxxxxxxx>
> > > Closes: https://syzkaller.appspot.com/bug?extid=a225ee3df7e7f9372dbe
> > > Fixes: a6aa8fca4d79 ("dma-buf/sw-sync: Reduce irqsave/irqrestore from known context")
> > > Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> > Reviewed-by: Christian König <christian.koenig@xxxxxxx>
> Thank you. Who can take this patch?

I pushed it to drm-misc-fixes.

Thanks,
Christian.

> > > ---
> > >    drivers/dma-buf/sync_debug.c | 4 ++--
> > >    1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c
> > > index 101394f16930..237bce21d1e7 100644
> > > --- a/drivers/dma-buf/sync_debug.c
> > > +++ b/drivers/dma-buf/sync_debug.c
> > > @@ -110,12 +110,12 @@ static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj)
> > >          seq_printf(s, "%s: %d\n", obj->name, obj->value);
> > >    -    spin_lock_irq(&obj->lock);
> > > +    spin_lock(&obj->lock); /* Caller already disabled IRQ. */
> > >        list_for_each(pos, &obj->pt_list) {
> > >            struct sync_pt *pt = container_of(pos, struct sync_pt, link);
> > >            sync_print_fence(s, &pt->base, false);
> > >        }
> > > -    spin_unlock_irq(&obj->lock);
> > > +    spin_unlock(&obj->lock);
> > >    }
> > >      static void sync_print_sync_file(struct seq_file *s,