]> git.karo-electronics.de Git - linux-beck.git/commit
drm/i915: Use batch length instead of object size in command parser
authorBrad Volkin <bradley.d.volkin@intel.com>
Thu, 11 Dec 2014 20:13:10 +0000 (12:13 -0800)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Tue, 16 Dec 2014 09:39:09 +0000 (10:39 +0100)
commitb9ffd80ed659c559152c042e74741f4f60cac691
tree13d37c669c3fb47d675984fd3e6b434d494e4f3d
parent78a423772d08eb5a048765a883b5b5a308ea0d0f
drm/i915: Use batch length instead of object size in command parser

Previously we couldn't trust the user-supplied batch length because
it came directly from userspace (i.e. untrusted code). It would have
affected what commands software parsed without regard to what hardware
would actually execute, leaving a potential hole.

With the parser now copying the user supplied batch buffer and writing
MI_NOP commands to any space after the copied region, we can safely use
the batch length input. This should be a performance win as the actual
batch length is frequently much smaller than the allocated object size.

v2: Fix handling of non-zero batch_start_offset

Issue: VIZ-4719
Signed-off-by: Brad Volkin <bradley.d.volkin@intel.com>
Reviewed-By: Jon Bloomfield <jon.bloomfield@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/i915_cmd_parser.c
drivers/gpu/drm/i915/i915_drv.h
drivers/gpu/drm/i915/i915_gem_execbuffer.c