Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 505a8ec7 authored by Chris Wilson's avatar Chris Wilson Committed by Linus Torvalds
Browse files

Revert "drm/i915/userptr: Acquire the page lock around set_page_dirty()" 



The userptr put_pages can be called from inside try_to_unmap, and so
enters with the page lock held on one of the object's backing pages. We
cannot take the page lock ourselves for fear of recursion.

Reported-by: default avatarLionel Landwerlin <lionel.g.landwerlin@intel.com>
Reported-by: default avatarMartin Wilck <Martin.Wilck@suse.com>
Reported-by: default avatarLeo Kraav <leho@kraav.com>
Fixes: aa56a292 ("drm/i915/userptr: Acquire the page lock around set_page_dirty()")
References: https://bugzilla.kernel.org/show_bug.cgi?id=203317


Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 98dcb386

drivers/gpu/drm/i915/gem/i915_gem_userptr.c

+1 −9
Original line number Diff line number Diff line
@@ -664,15 +664,7 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj, 


	for_each_sgt_page(page, sgt_iter, pages) {

		if (obj->mm.dirty)

			/*

			 * As this may not be anonymous memory (e.g. shmem)

			 * but exist on a real mapping, we have to lock

			 * the page in order to dirty it -- holding

			 * the page reference is not sufficient to

			 * prevent the inode from being truncated.

			 * Play safe and take the lock.

			 */

			set_page_dirty_lock(page);

			set_page_dirty(page);



		mark_page_accessed(page);

		put_page(page);