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Mario Kleiner 574fe59ef0 Fix RandR leasing for more than 1 simultaneously active lease.
Due to a switched order of parameters in the xorg_list_add()
call inside ProcRRCreateLease(), adding a new lease for RandR
output leasing does not actually add the new RRLeasePtr lease
record to the list of existing leases for a X-Screen, but instead
replaces the existing list with a new list that has the new lease
as the only element, and probably leaks a bit of memory.

Therefore the server "forgets" all active leases for a screen,
except for the last added lease. If multiple leases are created
in a session, then destruction of all leases but the last one
will fail in many cases, e.g., during server shutdown in
RRCloseScreen(), or resource destruction, e.g., in
RRCrtcDestroyResource().

Most importantly, it fails if a client simply close(fd)'es the
DRM master descriptor to release a lease, quits, gets killed or
crashes. In this case the kernel will destroy the lease and shut
down the display output, then send a lease event via udev to the
ddx, which e.g., in the modesetting-ddx will trigger a call to
drmmode_validate_leases().

That function is supposed to detect the released lease and tell
the server to terminate the lease on the server side as well,
via xf86CrtcLeaseTerminated(), but this doesn't happen for all
the leases the server has forgotten. The end result is a dead
video output, as the server won't reinitialize the crtc's
corresponding to the terminated but forgotten lease.

This bug was observed when using the amdvlk AMD OSS Vulkan
driver and trying to lease multiple VKDisplay's, and also
under Mesa radv, as both Mesa Vulkan/WSI/Display and amdvlk
terminate leases by simply close()ing the lease fd, not by
sending explicit RandR protocol requests to free leases.

Leasing worked, but ending a session with multiple active
leases ended in a lot of unpleasant darkness.

Fixing the wrong argument order to xorg_list_add() fixes the
problem. Tested on single-X-Screen and dual-X-Screen setups,
with one, two or three active leases.

Please merge this for the upcoming server 21.1 branch.
Merging into server 1.20 would also make a lot of sense.

Fixes: e4e3447603
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Reviewed-by: Keith Packard <keithp@keithp.com>
(cherry picked from commit f467f85ca1)
2021-10-26 21:39:04 +02:00
.gitlab-ci gitlab-ci: Add ccache to docker image, and leave in autotools 2019-02-22 11:55:31 +01:00
Xext configure: Build hashtable for Xres and glvnd 2020-11-09 11:35:30 +01:00
Xi Fix XChangeFeedbackControl() request underflow 2021-04-13 15:55:03 +02:00
composite Switch automatic composite update to WorkQueue 2018-10-05 09:14:18 +02:00
config Revert "linux: Make platform device probe less fragile" 2020-09-08 10:50:38 +02:00
damageext Use ARRAY_SIZE all over the tree 2017-10-30 13:45:20 -04:00
dbe meson: Distribute more SDK headers 2018-04-02 13:42:08 -04:00
dix dix: Guard against non-existing PtrFeedbackPtr 2021-06-08 08:02:37 +00:00
doc doc: Update URLs in Xserver-DTrace.xml 2020-08-18 04:12:09 +00:00
dri3 dri3: Fix XACE access mode for open and get_supported_modifiers 2019-02-20 14:25:58 -05:00
exa Restrict 1x1 pixmap filling optimization to GXcopy 2020-02-06 17:54:36 +01:00
fb fboverlay: move bpp checks above malloc 2018-10-04 17:26:09 +02:00
glamor glamor: Avoid using GL_QUADS on V3D 2021-06-14 23:39:37 +00:00
glx glx: Fix use after free in MakeCurrent 2021-06-26 21:13:41 +00:00
hw modesetting: unflip not possible when glamor is not set 2021-07-29 11:55:40 +02:00
include xquartz: Remove check for libdispatch now that we don't support pre-SnowLeopard 2021-02-01 23:09:54 -08:00
m4 Add ax_pthread.m4 to m4/ 2016-05-29 19:20:51 -07:00
man man: s/__/@/g 2018-03-27 10:13:17 -04:00
mi mi: Add a default no-op miSourceValidate 2019-11-18 14:23:15 -05:00
miext miext/sync: Make struct _SyncObject::initialized fully ABI compatible 2019-09-26 18:26:45 +02:00
os os: Remove support for Tiger and earlier versions of macOS 2021-02-01 23:07:26 -08:00
present present: fallback get_crtc to return crtc belonging to screen with present extension 2021-07-29 11:55:38 +02:00
pseudoramiX Unvalidated lengths 2017-10-10 23:33:34 +02:00
randr Fix RandR leasing for more than 1 simultaneously active lease. 2021-10-26 21:39:04 +02:00
record Fix XRecordRegisterClients() Integer underflow 2020-08-25 17:13:31 +02:00
render dix: Call SourceValidate before GetImage 2019-11-18 14:23:38 -05:00
test Fix building with `-fno-common` 2020-03-07 11:58:57 -08:00
xfixes xfixes: Restore monitoring of animated cursors 2018-02-14 13:52:45 -05:00
xkb xkb: Fix heap overflow caused by optimized away min. 2020-12-16 10:14:12 +01:00
.appveyor.yml appveyor: use meson 2018-03-21 10:16:44 -04:00
.dir-locals.el Add .dir-locals.el 2013-08-17 12:17:36 +02:00
.gitignore .gitignore: Add new autotools file 'test-driver' 2014-04-21 13:41:42 -07:00
.gitlab-ci.yml Revert "gitlab-ci: Only run docker-image stage if relevant source files change" 2019-03-25 12:45:52 +01:00
.travis.yml Drop Travis Linux build in favour of GitLab CI 2019-02-22 11:52:42 +01:00
COPYING modesetting: Merge modesetting's COPYING into the xserver's. 2014-09-15 12:46:02 -07:00
Makefile.am Update README for gitlab migration 2019-02-20 14:22:02 -05:00
README.md Update README for gitlab migration 2019-02-20 14:22:02 -05:00
autogen.sh autogen: Set a default subject prefix for patches 2016-02-08 17:41:38 -05:00
configure.ac xserver 1.20.13 2021-07-29 11:23:15 -07:00
devbook.am doc: Create a script to filter xmlto output 2015-01-05 14:24:06 -08:00
docbook.am docbook.am: embed css styles inside the HTML HEAD element 2011-09-21 14:07:49 -07:00
fix-miregion Change region implementation names to eliminate the 'mi' prefix 2010-06-05 17:47:32 -07:00
fix-miregion-private Change region implementation names to eliminate the 'mi' prefix 2010-06-05 17:47:32 -07:00
fix-patch-whitespace Rename region macros to eliminate screen argument 2010-06-05 18:59:00 -07:00
fix-region Rename region macros to eliminate screen argument 2010-06-05 18:59:00 -07:00
manpages.am man: Fix automake seddery 2018-05-08 12:15:30 -04:00
meson.build xserver 1.20.13 2021-07-29 11:23:15 -07:00
meson_options.txt meson: Add configuration of listening on tcp, unix and local 2018-08-01 11:01:37 -04:00
xorg-server.m4 macros: clarify documentation 2012-11-05 13:24:57 -06:00
xorg-server.pc.in xfree86: link modules against Xorg symbols on Cygwin 2012-04-05 21:57:07 -05:00
xserver.ent.in doc: relocate xserver.ent in the package root directory 2011-05-14 11:22:26 -07:00

X Server

The X server accepts requests from client applications to create windows, which are (normally rectangular) "virtual screens" that the client program can draw into.

Windows are then composed on the actual screen by the X server (or by a separate composite manager) as directed by the window manager, which usually communicates with the user via graphical controls such as buttons and draggable titlebars and borders.

For a comprehensive overview of X Server and X Window System, consult the following article: https://en.wikipedia.org/wiki/X_server

All questions regarding this software should be directed at the Xorg mailing list:

https://lists.freedesktop.org/mailman/listinfo/xorg

The master development code repository can be found at:

https://gitlab.freedesktop.org/xorg/xserver

For patch submission instructions, see:

https://www.x.org/wiki/Development/Documentation/SubmittingPatches

As with other projects hosted on freedesktop.org, X.Org follows its Code of Conduct, based on the Contributor Covenant. Please conduct yourself in a respectful and civilized manner when using the above mailing lists, bug trackers, etc:

https://www.freedesktop.org/wiki/CodeOfConduct