[Intel-gfx] [PATCH 1/3] drm: Restore driver.preclose() for all to use

Chris Wilson chris at chris-wilson.co.uk
Thu Jul 23 17:21:17 UTC 2020


An unfortunate sequence of events, but it turns out there is a valid
usecase for being able to free/decouple the driver objects before they
are freed by the DRM core. In particular, if we have a pointer into a
drm core object from inside a driver object, that pointer needs to be
nerfed *before* it is freed so that concurrent access (e.g. debugfs)
does not following the dangling pointer.

The legacy marker was adding in the code movement from drp_fops.c to
drm_file.c

References: 9acdac68bcdc ("drm: rename drm_fops.c to drm_file.c")
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter at intel.com>
Cc: Gustavo Padovan <gustavo.padovan at collabora.com>
Cc: CQ Tang <cq.tang at intel.com>
Cc: <stable at vger.kernel.org> # v4.12+
---
 drivers/gpu/drm/drm_file.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index 0ac4566ae3f4..7b4258d6f7cc 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -258,8 +258,7 @@ void drm_file_free(struct drm_file *file)
 		  (long)old_encode_dev(file->minor->kdev->devt),
 		  atomic_read(&dev->open_count));
 
-	if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
-	    dev->driver->preclose)
+	if (dev->driver->preclose)
 		dev->driver->preclose(dev, file);
 
 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
-- 
2.20.1



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