From 505a8ec7e11ae5236c4a154a1e24ef49a8349600 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 12 Sep 2019 13:56:34 +0100 Subject: [PATCH] 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 Reported-by: Martin Wilck Reported-by: Leo Kraav Fixes: aa56a292ce62 ("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 Cc: Tvrtko Ursulin Cc: Jani Nikula Cc: Joonas Lahtinen Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index 2caa594322bc..528b61678334 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -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); -- 2.34.1