redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

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: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reported-by: Martin Wilck <Martin.Wilck@suse.com>
Reported-by: Leo Kraav <leho@kraav.com>
Fixes: aa56a292ce ("drm/i915/userptr: Acquire the page lock around set_page_dirty()")
References: https://bugzilla.kernel.org/show_bug.cgi?id=203317
Signed-off-by: Chris 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: Linus Torvalds <torvalds@linux-foundation.org>
alistair/sunxi64-5.4-dsi
Chris Wilson 2019-09-12 13:56:34 +01:00 committed by Linus Torvalds
parent 98dcb386e5
commit 505a8ec7e1
1 changed files with 1 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/gpu/drm/i915/gem/i915_gem_userptr.c
View File

@ -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);