linux/drivers/gpu/drm
Chris Wilson b47b30ccda drm/i915: Avoid might_fault during pwrite whilst holding our mutex
... and so prevent a potential circular reference:

  [ 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.

When the locking around the pwrite ioctl was simplified, I did not spot
that the phys path never took any locks and so we introduced this
potential circular reference.

Reported-by: Uwe Helm <uwe.helm@googlemail.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
2010-11-08 09:19:11 +00:00
..
i2c
i810 Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-10-26 18:57:59 -07:00
i830 Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-10-26 18:57:59 -07:00
i915 drm/i915: Avoid might_fault during pwrite whilst holding our mutex 2010-11-08 09:19:11 +00:00
mga Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-10-26 18:57:59 -07:00
nouveau Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-10-26 18:57:59 -07:00
r128 Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-10-26 18:57:59 -07:00
radeon Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-10-26 18:57:59 -07:00
savage Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-10-26 18:57:59 -07:00
sis Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-10-26 18:57:59 -07:00
tdfx Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-10-26 18:57:59 -07:00
ttm Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-10-26 18:57:59 -07:00
via Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-10-26 18:57:59 -07:00
vmwgfx Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-10-26 18:57:59 -07:00
ati_pcigart.c
drm_agpsupport.c
drm_auth.c
drm_buffer.c
drm_bufs.c
drm_cache.c
drm_context.c
drm_crtc.c drm: vmwgfx: Add a struct drm_file parameter to the dirty framebuffer callback 2010-10-06 11:29:41 +10:00
drm_crtc_helper.c
drm_debugfs.c
drm_dma.c
drm_dp_i2c_helper.c
drm_drv.c Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-10-26 18:57:59 -07:00
drm_edid.c drm/edid: add helper function to detect monitor audio capability 2010-10-19 09:17:32 +01:00
drm_edid_modes.h
drm_encoder_slave.c
drm_fb_helper.c drm, kdb, kms: Change mode_set_base_atomic() enter argument to be an enum 2010-10-19 14:13:33 +10:00
drm_fops.c
drm_gem.c Merge remote branch 'korg/drm-fixes' into drm-vmware-next 2010-10-06 11:10:48 +10:00
drm_global.c
drm_hashtab.c
drm_info.c Merge remote branch 'korg/drm-fixes' into drm-vmware-next 2010-10-06 11:10:48 +10:00
drm_ioc32.c
drm_ioctl.c
drm_irq.c
drm_lock.c
drm_memory.c
drm_mm.c
drm_modes.c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-10-24 13:41:39 -07:00
drm_pci.c
drm_platform.c
drm_proc.c
drm_scatter.c
drm_sman.c
drm_stub.c
drm_sysfs.c
drm_trace.h
drm_trace_points.c
drm_vm.c Merge remote branch 'korg/drm-fixes' into drm-vmware-next 2010-10-06 11:10:48 +10:00
Kconfig BKL: introduce CONFIG_BKL. 2010-10-21 15:44:13 +02:00
Makefile
README.drm

************************************************************
* For the very latest on DRI development, please see:      *
*     http://dri.freedesktop.org/                          *
************************************************************

The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).

The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:

    1. The DRM provides synchronized access to the graphics hardware via
       the use of an optimized two-tiered lock.

    2. The DRM enforces the DRI security policy for access to the graphics
       hardware by only allowing authenticated X11 clients access to
       restricted regions of memory.

    3. The DRM provides a generic DMA engine, complete with multiple
       queues and the ability to detect the need for an OpenGL context
       switch.

    4. The DRM is extensible via the use of small device-specific modules
       that rely extensively on the API exported by the DRM module.


Documentation on the DRI is available from:
    http://dri.freedesktop.org/wiki/Documentation
    http://sourceforge.net/project/showfiles.php?group_id=387
    http://dri.sourceforge.net/doc/

For specific information about kernel-level support, see:

    The Direct Rendering Manager, Kernel Support for the Direct Rendering
    Infrastructure
    http://dri.sourceforge.net/doc/drm_low_level.html

    Hardware Locking for the Direct Rendering Infrastructure
    http://dri.sourceforge.net/doc/hardware_locking_low_level.html

    A Security Analysis of the Direct Rendering Infrastructure
    http://dri.sourceforge.net/doc/security_low_level.html