INFO: possible circular locking dependency detected [v2.6.37-rc1-152-g6c88078]

[Uwe Helm]

Hi,

I've been seeing these lately, Xorg version is 1.9.0 with latest git kernel.

=======================================================


[ INFO: possible circular locking dependency detected ]


2.6.37-rc1-uwe1+ #4


-------------------------------------------------------


Xorg/1401 is trying to acquire lock:


 (&mm->mmap_sem){++++++}, at: [<c01e4ddb>] might_fault+0x4b/0xa0





but task is already holding lock:


 (&dev->struct_mutex){+.+.+.}, at: [<f869c3ac>]
i915_mutex_lock_interruptible+0x3c/0x60 [i915]




which lock already depends on the new lock.








the existing dependency chain (in reverse order) is:





-> #1 (&dev->struct_mutex){+.+.+.}:


       [<c01738ec>] lock_acquire+0x7c/0x120


       [<c04d3560>] mutex_lock_nested+0x60/0x330


       [<f810c7aa>] drm_gem_mmap+0x3a/0x140 [drm]


       [<c01ec202>] mmap_region+0x2e2/0x430


       [<c01ec59f>] do_mmap_pgoff+0x24f/0x2f0


       [<c01ec6bb>] sys_mmap_pgoff+0x7b/0x110


       [<c0102f97>] sysenter_do_call+0x12/0x36





-> #0 (&mm->mmap_sem){++++++}:


       [<c0173549>] __lock_acquire+0x14a9/0x17d0


       [<c01738ec>] lock_acquire+0x7c/0x120


       [<c01e4e0c>] might_fault+0x7c/0xa0


       [<c032dfad>] _copy_from_user+0x3d/0x130


       [<f869cdec>] i915_gem_pwrite_ioctl+0x18c/0xb20 [i915]


       [<f810afd2>] drm_ioctl+0x1e2/0x440 [drm]


       [<c0216dcd>] do_vfs_ioctl+0x9d/0x6c0


       [<c0217457>] sys_ioctl+0x67/0x80


       [<c0102f97>] sysenter_do_call+0x12/0x36





other info that might help us debug this:





1 lock held by Xorg/1401:


 #0:  (&dev->struct_mutex){+.+.+.}, at: [<f869c3ac>]
i915_mutex_lock_interruptible+0x3c/0x60 [i915]



stack backtrace:


Pid: 1401, comm: Xorg Not tainted 2.6.37-rc1-uwe1+ #4


Call Trace:


 [<c04d12de>] ? printk+0x1d/0x1f


 [<c01714f2>] print_circular_bug+0xc2/0xd0


 [<c0173549>] __lock_acquire+0x14a9/0x17d0


 [<c04d82c9>] ? sub_preempt_count+0x9/0x50


 [<c01738ec>] lock_acquire+0x7c/0x120


 [<c01e4ddb>] ? might_fault+0x4b/0xa0


 [<c01e4e0c>] might_fault+0x7c/0xa0


 [<c01e4ddb>] ? might_fault+0x4b/0xa0


 [<c032dfad>] _copy_from_user+0x3d/0x130


 [<f869cdec>] i915_gem_pwrite_ioctl+0x18c/0xb20 [i915]


 [<c01e4ddb>] ? might_fault+0x4b/0xa0


 [<f810afd2>] drm_ioctl+0x1e2/0x440 [drm]


 [<f869cc60>] ? i915_gem_pwrite_ioctl+0x0/0xb20 [i915]


 [<c02f36d3>] ? smk_access+0xb3/0x1f0


 [<c02f3914>] ? smk_curacc+0x74/0xa0


 [<f810adf0>] ? drm_ioctl+0x0/0x440 [drm]


 [<c0216dcd>] do_vfs_ioctl+0x9d/0x6c0


 [<c0217457>] sys_ioctl+0x67/0x80


 [<c0102f97>] sysenter_do_call+0x12/0x36

thanks,
Uwe
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/dri-devel/attachments/20101107/eebe1529/attachment-0001.html>