Inorder to serialise the closing of the file descriptor and its subsequent release of client requests with i915_gem_free_request(), we need to hold the struct_mutex in i915_gem_release(). Failing to do so has the potential to trigger an OOPS, later with a use-after-free. Testcase: igt/gem_close_race Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=70874 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=71029 Reported-by: Eric Anholt <eric@xxxxxxxxxx> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- drivers/gpu/drm/i915/i915_dma.c | 2 ++ drivers/gpu/drm/i915/i915_gem_context.c | 2 -- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index 38181a5691e2..0864a39a1b09 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -1847,8 +1847,10 @@ void i915_driver_lastclose(struct drm_device * dev) void i915_driver_preclose(struct drm_device * dev, struct drm_file *file_priv) { + mutex_lock(&dev->struct_mutex); i915_gem_context_close(dev, file_priv); i915_gem_release(dev, file_priv); + mutex_unlock(&dev->struct_mutex); } void i915_driver_postclose(struct drm_device *dev, struct drm_file *file) diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c index ad31d865047a..dd3b8cdfd72e 100644 --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -348,10 +348,8 @@ void i915_gem_context_close(struct drm_device *dev, struct drm_file *file) { struct drm_i915_file_private *file_priv = file->driver_priv; - mutex_lock(&dev->struct_mutex); idr_for_each(&file_priv->context_idr, context_idr_cleanup, NULL); idr_destroy(&file_priv->context_idr); - mutex_unlock(&dev->struct_mutex); } static struct i915_hw_context * -- 1.8.5.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
