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182b17c8dc
After a vmalloc failure in ttm_dma_tt_alloc_page_directory(), ttm_dma_tt_init() will call ttm_tt_destroy() to cleanup, and end up inside the driver's unpopulate() hook when populate() has never yet been called. On nouveau, the first issue to be hit because of this is that dma_address[] may be a NULL pointer. After working around this, ttm_pool_unpopulate() may potentially hit the same issue with the pages[] array. It seems to make more sense to avoid calling unpopulate on already unpopulated TTMs than to add checks to all the implementations. Signed-off-by: Ben Skeggs <bskeggs@redhat.com> Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com> Cc: stable@vger.kernel.org Cc: Jerome Glisse <jglisse@redhat.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
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* 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