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@xxxxxxxxxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxxx>
Cc: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxx>
Cc: CQ Tang <cq.tang@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # 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
