Re: [PATCH] drm/nouveau: initialize chan->fence.lock before use

[Ben Skeggs <skeggsb-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On Sun, 2011-10-09 at 21:24 +0200, Marcin Slusarz wrote:
> On Fri, Sep 09, 2011 at 02:16:42PM +0200, Marcin Slusarz wrote:
> > Fence lock needs to be initialized before any call to nouveau_channel_put
> > because it calls nouveau_channel_idle->nouveau_fence_update which uses
> > fence lock.
Apologies, I missed this the first time around.  I've queued it up and
will push today.

Thanks,
Ben.

> > 
> > BUG: spinlock bad magic on CPU#0, test/24134
> >  lock: ffff88019f90dba8, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
> > Pid: 24134, comm: test Not tainted 3.0.0-nv+ #800
> > Call Trace:
> >  spin_bug+0x9c/0xa3
> >  do_raw_spin_lock+0x29/0x13c
> >  _raw_spin_lock+0x1e/0x22
> >  nouveau_fence_update+0x2d/0xf1
> >  nouveau_channel_idle+0x22/0xa0
> >  nouveau_channel_put_unlocked+0x84/0x1bd
> >  nouveau_channel_put+0x20/0x24
> >  nouveau_channel_alloc+0x4ec/0x585
> >  nouveau_ioctl_fifo_alloc+0x50/0x130
> >  drm_ioctl+0x289/0x361
> >  do_vfs_ioctl+0x4dd/0x52c
> >  sys_ioctl+0x42/0x65
> >  system_call_fastpath+0x16/0x1b
> > 
> > It's easily triggerable from userspace.
> > 
> > Additionally remove double initialization of chan->fence.pending.
> > 
> > Signed-off-by: Marcin Slusarz <marcin.slusarz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> > Cc: stable-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org
> > ---
> >  drivers/gpu/drm/nouveau/nouveau_channel.c |    1 +
> >  drivers/gpu/drm/nouveau/nouveau_fence.c   |    2 --
> >  2 files changed, 1 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/nouveau/nouveau_channel.c b/drivers/gpu/drm/nouveau/nouveau_channel.c
> > index 85be745..62c09b0 100644
> > --- a/drivers/gpu/drm/nouveau/nouveau_channel.c
> > +++ b/drivers/gpu/drm/nouveau/nouveau_channel.c
> > @@ -158,6 +158,7 @@ nouveau_channel_alloc(struct drm_device *dev, struct nouveau_channel **chan_ret,
> >  	INIT_LIST_HEAD(&chan->nvsw.vbl_wait);
> >  	INIT_LIST_HEAD(&chan->nvsw.flip);
> >  	INIT_LIST_HEAD(&chan->fence.pending);
> > +	spin_lock_init(&chan->fence.lock);
> >  
> >  	/* setup channel's memory and vm */
> >  	ret = nouveau_gpuobj_channel_init(chan, vram_handle, gart_handle);
> > diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c b/drivers/gpu/drm/nouveau/nouveau_fence.c
> > index c499591..614e37a 100644
> > --- a/drivers/gpu/drm/nouveau/nouveau_fence.c
> > +++ b/drivers/gpu/drm/nouveau/nouveau_fence.c
> > @@ -568,8 +568,6 @@ nouveau_fence_channel_init(struct nouveau_channel *chan)
> >  			return ret;
> >  	}
> >  
> > -	INIT_LIST_HEAD(&chan->fence.pending);
> > -	spin_lock_init(&chan->fence.lock);
> >  	atomic_set(&chan->fence.last_sequence_irq, 0);
> >  	return 0;
> >  }
> > -- 
> 
> ping