The execbuffer handle and exec_link were moved from the object into the
vma. As the vma may be unbound and destroyed whilst attempting to
reserve the execbuffer objects (either through a forced unbind to fix up
a misalignment or through an evict-everything call) we need to prevent
the free of the i915_vma itself. Otherwise not only is the list of
objects to reserve corrupt, but we continue to reference stale vma
entries.
Fixes kernel crash with i-g-t/gem_evict_everything
This regression has been introduced in
commit 04038a515d6eda6dd0857c0ade0b3950d372f4c0
Author: Ben Widawsky <ben@bwidawsk.net>
AuthorDate: Wed Aug 14 11:38:36 2013 +0200
drm/i915: Convert execbuf code to use vmas
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
References: http://www.spinics.net/lists/intel-gfx/msg32038.html
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=68298
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
************************************************************
* 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
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