xserver/hw/xwayland
Olivier Fourdan 3362422e84 xwayland: remove dirty window unconditionally on unrealize
This is a rare occurrence of a crash in Xwayland for which I don't have
the reproducing steps, just a core file.

The backtrace looks as follow:

  #0  raise () from /usr/lib64/libc.so.6
  #1  abort () from /usr/lib64/libc.so.6
  #2  OsAbort () at utils.c:1361
  #3  AbortServer () at log.c:877
  #4  FatalError () at log.c:1015
  #5  OsSigHandler () at osinit.c:154
  #6  <signal handler called>
  #7  xwl_glamor_pixmap_get_wl_buffer () at xwayland-glamor.c:162
  #8  xwl_screen_post_damage () at xwayland.c:514
  #9  block_handler () at xwayland.c:665
  #10 BlockHandler () at dixutils.c:388
  #11 WaitForSomething () at WaitFor.c:219
  #12 Dispatch () at dispatch.c:422
  #13 dix_main () at main.c:287

The crash is caused by dereferencing “xwl_pixmap->buffer” in
xwl_glamor_pixmap_get_wl_buffer() because “xwl_pixmap” is NULL.

Reason for this is because the corresponding pixmap is from the root
window and xwayland is rootless by default.

This can happen if the window was mapped, redirected, damaged and
unredirected immediately, before the damage is processed by Xwayland.

Make sure to remove the dirty window from the damage list on unrealize
to prevent this from happening.

Credit goes to Adam Jackson <ajax@nwnk.net> and Daniel Stone
<daniel@fooishbar.org> for finding the root cause the issue.

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
2018-01-25 10:31:45 -05:00
..
.gitignore xwayland: Bind pointer constraints global 2016-10-05 13:50:46 -04:00
Makefile.am xwayland: Add optional xdg-output support 2018-01-24 11:34:59 -05:00
drm.xml wayland: Sync drm.xml with Mesa 2017-07-05 10:13:04 -04:00
meson.build xwayland: Add optional xdg-output support 2018-01-24 11:34:59 -05:00
xwayland-cursor.c xwayland: Fix non-argb cursor conversion 2017-12-06 10:15:57 -05:00
xwayland-cvt.c xwayland: Add hack for FWXGA resolution #99574 2017-02-08 12:32:16 -05:00
xwayland-glamor-xv.c xwayland: use the lowercase xnf.*alloc API 2017-09-06 08:56:39 +10:00
xwayland-glamor.c xwayland: Stop printing the EGL version 2017-11-07 15:57:54 -05:00
xwayland-input.c xwayland: Support for BTN_STYLUS3 kernel events 2018-01-25 18:26:09 +10:00
xwayland-output.c xwayland: Add optional xdg-output support 2018-01-24 11:34:59 -05:00
xwayland-shm.c xserver: Check the right HAVE_*_CONFIG_H. 2017-03-23 13:17:39 -04:00
xwayland-vidmode.c xwayland: Pretend we support viewport in vidmode 2016-03-28 14:10:59 -04:00
xwayland.c xwayland: remove dirty window unconditionally on unrealize 2018-01-25 10:31:45 -05:00
xwayland.h xwayland: Add optional xdg-output support 2018-01-24 11:34:59 -05:00