Description of problem:

The following error showed up in the kernel messages

[ INFO: possible circular locking dependency detected ]
2.6.33.1-19.fc13.x86_64 #1
-------------------------------------------------------
Xorg/3531 is trying to acquire lock:
 (&mm->mmap_sem){++++++}, at: [<ffffffff810f1d8c>] might_fault+0x5c/0xac

but task is already holding lock:
 (&dev->struct_mutex){+.+.+.}, at: [<ffffffffa00807b5>] nouveau_gem_ioctl_pushbuf+0x1e8/0xcdf [nouveau]

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&dev->struct_mutex){+.+.+.}:
       [<ffffffff8107e833>] __lock_acquire+0xb7d/0xd2c
       [<ffffffff8107eabe>] lock_acquire+0xdc/0x102
       [<ffffffff8147766d>] __mutex_lock_common+0x4b/0x392
       [<ffffffff81477a78>] mutex_lock_nested+0x3e/0x43
       [<ffffffffa001ede9>] drm_mmap+0x38/0x5f [drm]
       [<ffffffffa0081436>] nouveau_ttm_mmap+0x34/0x46 [nouveau]
       [<ffffffff810fa435>] mmap_region+0x2ac/0x4cb
       [<ffffffff810fa8ec>] do_mmap_pgoff+0x298/0x2fb
       [<ffffffff810faa45>] sys_mmap_pgoff+0xf6/0x12e
       [<ffffffff8100dd89>] sys_mmap+0x22/0x24
       [<ffffffff81009c72>] system_call_fastpath+0x16/0x1b

-> #0 (&mm->mmap_sem){++++++}:
       [<ffffffff8107e6dd>] __lock_acquire+0xa27/0xd2c
       [<ffffffff8107eabe>] lock_acquire+0xdc/0x102
       [<ffffffff810f1db9>] might_fault+0x89/0xac
       [<ffffffffa0080045>] validate_list+0x22b/0x288 [nouveau]
       [<ffffffffa0080b65>] nouveau_gem_ioctl_pushbuf+0x598/0xcdf [nouveau]
       [<ffffffffa0019418>] drm_ioctl+0x28f/0x373 [drm]
       [<ffffffff8112c054>] vfs_ioctl+0x32/0xa6
       [<ffffffff8112c5d4>] do_vfs_ioctl+0x490/0x4d6
       [<ffffffff8112c670>] sys_ioctl+0x56/0x79
       [<ffffffff81009c72>] system_call_fastpath+0x16/0x1b

other info that might help us debug this:

1 lock held by Xorg/3531:
 #0:  (&dev->struct_mutex){+.+.+.}, at: [<ffffffffa00807b5>] nouveau_gem_ioctl_pushbuf+0x1e8/0xcdf [nouveau]

stack backtrace:
Pid: 3531, comm: Xorg Not tainted 2.6.33.1-19.fc13.x86_64 #1
Call Trace:
 [<ffffffff8107d88d>] print_circular_bug+0xaf/0xbd
 [<ffffffff8107e6dd>] __lock_acquire+0xa27/0xd2c
 [<ffffffff8107eabe>] lock_acquire+0xdc/0x102
 [<ffffffff810f1d8c>] ? might_fault+0x5c/0xac
 [<ffffffff810f1db9>] might_fault+0x89/0xac
 [<ffffffff810f1d8c>] ? might_fault+0x5c/0xac
 [<ffffffffa0061fd1>] ? ttm_bo_validate+0xae/0xf7 [ttm]
 [<ffffffffa0080045>] validate_list+0x22b/0x288 [nouveau]
 [<ffffffffa0080b65>] nouveau_gem_ioctl_pushbuf+0x598/0xcdf [nouveau]
 [<ffffffffa0019418>] drm_ioctl+0x28f/0x373 [drm]
 [<ffffffffa00805cd>] ? nouveau_gem_ioctl_pushbuf+0x0/0xcdf [nouveau]
 [<ffffffff8101031d>] ? sched_clock+0x9/0xd
 [<ffffffff810710fd>] ? sched_clock_local+0x1c/0x82
 [<ffffffff8112c054>] vfs_ioctl+0x32/0xa6
 [<ffffffff8112c5d4>] do_vfs_ioctl+0x490/0x4d6
 [<ffffffff8112c670>] sys_ioctl+0x56/0x79
 [<ffffffff81009c72>] system_call_fastpath+0x16/0x1b


Version-Release number of selected component (if applicable):

2.6.33.1-19.fc13.x86_64

How reproducible:

?

Steps to Reproduce:
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Actual results:

kernel message

Expected results:

No kernel message

Additional info: