On Tue, Oct 08, 2019 at 07:25:04PM +0200, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From cb6d7c7dc7ff8cace666ddec66334117a6068ce2 Mon Sep 17 00:00:00 2001 From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Date: Mon, 8 Jul 2019 15:03:27 +0100 Subject: [PATCH] drm/i915/userptr: Acquire the page lock around set_page_dirty() set_page_dirty says: For pages with a mapping this should be done under the page lock for the benefit of asynchronous memory errors who prefer a consistent dirty state. This rule can be broken in some special cases, but should be better not to. Under those rules, it is only safe for us to use the plain set_page_dirty calls for shmemfs/anonymous memory. Userptr may be used with real mappings and so needs to use the locked version (set_page_dirty_lock). Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203317 Fixes: 5cc9ed4b9a7a ("drm/i915: Introduce mapping of user pages into video memory (userptr) ioctl") References: 6dcc693bc57f ("ext4: warn when page is dirtied without buffers") Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20190708140327.26825-1-chris@xxxxxxxxxxxxxxxxxx
File got moved around. I've fixed it up and queued for 4.19-4.4. -- Thanks, Sasha
