lkml.org 
[lkml]   [2018]   [Jul]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.14 18/61] drm/qxl: Call qxl_bo_unref outside atomic context
Date
4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jeremy Cline <jcline@redhat.com>

commit 889ad63d41eea20184b0483e7e585e5b20fb6cfe upstream.

"qxl_bo_unref" may sleep, but calling "qxl_release_map" causes
"preempt_disable()" to be called and "preempt_enable()" isn't called
until "qxl_release_unmap" is used. Move the call to "qxl_bo_unref" out
from in between the two to avoid sleeping from an atomic context.

This issue can be demonstrated on a kernel with CONFIG_LOCKDEP=y by
creating a VM using QXL, using a desktop environment using Xorg, then
moving the cursor on or off a window.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1571128
Fixes: 9428088c90b6 ("drm/qxl: reapply cursor after resetting primary")
Cc: stable@vger.kernel.org
Signed-off-by: Jeremy Cline <jcline@redhat.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20180601200532.13619-1-jcline@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/qxl/qxl_display.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/qxl/qxl_display.c
+++ b/drivers/gpu/drm/qxl/qxl_display.c
@@ -630,7 +630,7 @@ static void qxl_cursor_atomic_update(str
struct qxl_cursor_cmd *cmd;
struct qxl_cursor *cursor;
struct drm_gem_object *obj;
- struct qxl_bo *cursor_bo = NULL, *user_bo = NULL;
+ struct qxl_bo *cursor_bo = NULL, *user_bo = NULL, *old_cursor_bo = NULL;
int ret;
void *user_ptr;
int size = 64*64*4;
@@ -684,7 +684,7 @@ static void qxl_cursor_atomic_update(str
cursor_bo, 0);
cmd->type = QXL_CURSOR_SET;

- qxl_bo_unref(&qcrtc->cursor_bo);
+ old_cursor_bo = qcrtc->cursor_bo;
qcrtc->cursor_bo = cursor_bo;
cursor_bo = NULL;
} else {
@@ -704,6 +704,9 @@ static void qxl_cursor_atomic_update(str
qxl_push_cursor_ring_release(qdev, release, QXL_CMD_CURSOR, false);
qxl_release_fence_buffer_objects(release);

+ if (old_cursor_bo)
+ qxl_bo_unref(&old_cursor_bo);
+
qxl_bo_unref(&cursor_bo);

return;

\
 
 \ /
  Last update: 2018-07-06 08:02    [W:0.188 / U:3.820 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site