If we leave xwayland in weston's process group, it can receive
signals from the controlling TTY intended for weston.
The easiest way to see this is to launch weston under gdb, start an
X client, and hit ctrl-c in the gdb session. The Xwayland server
will also catch the SIGINT, and the X client will be disconnected.
Instead, let's call setsid() when launching Xwayland, like we do
for launched clients.
Suggested-by: Hideyuki Nagase <hideyukn@microsoft.com>
Signed-off-by: Derek Foreman <derek.foreman@collabora.com>
[common equivalent of 77cf8cb006 in Xwayland from Pekka Paalanen; its
commit message follows]
Between fork() and exec() in the child process it is only safe to use
async-signal-safe functions. weston_log() definitely is not one, it
allocates memory and does whatnot.
weston_log() is also inappropriate for other reasons: the child process
has its own stream buffers and flight-recorder. No-one looks into the
child process' flight recorder, so messages would be lost there. The
logging machinery might also attempt to write into debug streams,
meaning both parent and child could be writing simultaneously.
It seems that the best we can do is to pre-bake an error message and
only write() it out if exec() fails. There is no mention that even
strerror_r() might be safe to call, so we don't.
Signed-off-by: Daniel Stone <daniels@collabora.com>
Use the custom_env framework we added for Xwayland when forking to
execute clients. This avoids calling the unsafe getenv in between fork
and exec.
Signed-off-by: Daniel Stone <daniels@collabora.com>
It was only a small function, and inlining it will allow us to make it
more safe without having to duplicate a ton of stuff.
Signed-off-by: Daniel Stone <daniels@collabora.com>
This doesn't actually stop us from calling setenv() in between fork()
and exec() when starting clients, but gets us closer to Xwayland's safe
implementation by reusing one of the helpers it added.
Signed-off-by: Daniel Stone <daniels@collabora.com>
Use the arg handling added in the previous commit so that the
environment is completely encapsulated inside the custom env.
Signed-off-by: Daniel Stone <daniels@collabora.com>
Rename the bits handling environment variables (currently, all of it),
so we have room to handle args as well.
No functional changes.
Signed-off-by: Daniel Stone <daniels@collabora.com>
Between fork() and exec() in the child process it is only safe to use
async-signal-safe functions. Painfully, setenv() is not listed as such.
Therefore we must craft our own custom environment, and we get no help
from libc with that.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Constructing argv before-hand is a little easier to look at, but this is
mostly just anticipating more changes to how Weston spawns processes in
general.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
We are already using pipe2() in many places, even in libweston, so let's
simplify the code here as well - not to mention avoid a theoretical
race.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Between fork() and exec() in the child process it is only safe to use
async-signal-safe functions. Surprisingly, snprintf() is not such
function. See e.g. https://stackoverflow.com/a/6771799 and how snprintf
is not listed in signal-safety(7) manual.
Therefore we must prepare the fd argument strings before fork(). That is
only possible if we also do not dup() fd in the child process. Hence we
remove the close-on-exec flag instead in the child process which has
copies of the parent's file descriptors. Fortunately fcntl() is safe.
struct fdstr is helping to reduce code clutter a bit.
Additionally, if fork() fails, we now clean up the fds we created.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Between fork() and exec() in the child process it is only safe to use
async-signal-safe functions. weston_log() definitely is not one, it
allocates memory and does whatnot.
weston_log() is also inappropriate for other reasons: the child process
has its own stream buffers and flight-recorder. No-one looks into the
child process' flight recorder, so messages would be lost there. The
logging machinery might also attempt to write into debug streams,
meaning both parent and child could be writing simultaneously.
It seems that the best we can do is to pre-bake an error message and
only write() it out if exec() fails. There is no mention that even
strerror_r() might be safe to call, so we don't.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Doing any kind of memory allocation calls between fork() and exec() in
the child process is prone to deadlocks and explosions. In general, only
async-signal-safe functions are safe there.
Move the config access to the parent process before fork() to avoid
problems.
See also:
https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/941#note_1457053
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This reverts commit 4aa885d4af.
Turns out the problem was not about dupping fds at all, but calling
non-async-signal-safe functions like strdup() between fork() and exec()
in the child process.
For more discussion, see:
https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/941#note_1457053
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This patch fixes the following:
AddressSanitizer:DEADLYSIGNAL
=================================================================
==528956==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000008 (pc 0x7fbc5d66bdd7 bp 0x7ffd465573c0 sp 0x7ffd46557398 T0)
==528956==The signal is caused by a WRITE memory access.
==528956==Hint: address points to the zero page.
#0 0x7fbc5d66bdd7 in wl_list_remove ../../git/wayland/src/wayland-util.c:56
#1 0x7fbc5cb8869e in wxw_compositor_destroy ../../git/weston/compositor/xwayland.c:357
#2 0x7fbc5baf3ca6 in weston_signal_emit_mutable ../../git/weston/shared/signal.c:62
#3 0x7fbc5ba4d6f9 in weston_compositor_destroy ../../git/weston/libweston/compositor.c:8639
#4 0x7fbc5cb7a5f2 in wet_main ../../git/weston/compositor/main.c:3772
#5 0x55bd13de2179 in main ../../git/weston/compositor/executable.c:33
#6 0x7fbc5be61d09 in __libc_start_main ../csu/libc-start.c:308
#7 0x55bd13de2099 in _start (/home/pq/local/bin/weston+0x1099)
The problem is triggered by configuring a bad path to Xwayland in
weston.ini, which causes exec() to fail. The fork() succeeded though,
which means the weston_process was already on the watch list, and the
watch can be handled, making sigchl_handler() leave the link
uninitialized.
Making sure the link remains removable fixes this.
Fixes: 18897253d4
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
While developing the new color management, keeping these old plugins
working would require extra work. Let's deprecate these to see if anyone
cares about them, pending removal after the Weston 11.0.0 release.
CI will keep building these in the "Full build" configuration only. Doc
and no-GL builds are no different for these plugins, so there these are
no longer built.
See https://gitlab.freedesktop.org/wayland/weston/-/issues/634
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This way the backends will the actual outputs. And at that point the backend
knows the compositor is shutting down so it can handle this differently if
necessary.
Afterwards wet_compositor_destroy_layout() just deletes the remaining
datastructures.
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
Replace an oft-duplicated pattern with a trivial helper function. In
doing so, we observe that the one special case (displayfd 'didn't need
to be CLOEXEC') was wrong, because the X server does fork itself
internally, so there is nothing wrong with setting CLOEXEC.
Signed-off-by: Daniel Stone <daniels@collabora.com>
For working around hardware limitations as explained in the man page.
Now added for completeness' sake without knowing if anyone will ever
need this.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
To support heterogeneous outputs, the output must be created by the
same backend as the head(s) it is created for. Solve this by always
creating an output with a first head to attach that determines the
backend to use. Skip already attached first heads in drm_try_attach().
See: https://gitlab.freedesktop.org/wayland/weston/-/issues/268
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Add a struct weston_head parameter to weston_compositor_create_output()
and fold weston_compositor_create_output_with_head() into it.
See: https://gitlab.freedesktop.org/wayland/weston/-/issues/268
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
It's bad form to set the same variable in multiple places, and not all
of them were even equivalent.
Move lcms2 finding to the root level build file only. It is still an
optional dependency like before, and the if-not-found checks are still
in place where actually needed.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This adds an option to program basic display color characteristics from
weston.ini. In the future there will be a way to set this information
from EDID, but because EDID is unreliable that will probably not be the
default. An ICC profile will likely override most or all of this. The
main reason to add this option is to be able to characterise HDR
monitors.
An 'output' section can have a key 'color_characteristics' (string)
set to a name. The name refers to any 'color_characteristics' section
with 'name' set to the same string.
The 'name' key of a 'color_characteristics' section cannot contain a
colon ':'. Names with colon in 'output' section key
'color_characteristics' value are reserved for future use, e.g. to
indicate that the metadata is to be taken from EDID instead of a
weston.ini section.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
We currently hardcode a 60Hz update rate for the rdp backend.
In some cases it may be useful to override this to increase the rate
for a faster monitor, or to decrease it to reduce network traffic.
Co-authored-by: Steve Pronovost <spronovo@microsoft.com>
Co-authored-by: Brenton DeGeer <brdegeer@microsoft.com>
Signed-off-by: Hideyuki Nagase <hideyukn@microsoft.com>
Signed-off-by: Steve Pronovost <spronovo@microsoft.com>
Signed-off-by: Brenton DeGeer <brdegeer@microsoft.com>
We already have a way for a single RDP client connection to be
passed from a parent process to a child using a combination
of environment variable (RDP_FD) and env var (--env-socket)
This patch allows a bound socket fd (as opposed to a client
connection) to be established in a parent process and provided
to the rdp backend. WSLg uses this to set up an AF_VSOCK
socket for communication between a Windows RDP client and a
weston compositor running under a hypervisor.
Co-authored-by: Hideyuki Nagase <hideyukn@microsoft.com>
Co-authored-by: Steve Pronovost <spronovo@microsoft.com>
Signed-off-by: Hideyuki Nagase <hideyukn@microsoft.com>
Signed-off-by: Steve Pronovost <spronovo@microsoft.com>
Signed-off-by: Brenton DeGeer <brdegeer@microsoft.com>
Rather than only filling weston_buffer information when we first come to
use it, add an explicit hook so we can fill the dimensions the first
time the buffer's attached.
Signed-off-by: Daniel Stone <daniels@collabora.com>
There are currently compatibility issues between FreeRDP's implementation
of the RemoteFX codec and Microsoft's implementation.
Perhaps this will be fixed in the future and this option can go away,
but for now it's necessary to have a way to disable the codec if the
windows client is going to be connecting to a weston server.
Signed-off-by: Derek Foreman <derek.foreman@collabora.com>
Found while running with b_sanitize=undefined, which yields:
runtime error: shift exponent 909199186 is too large for 32-bit type 'int'
Converts the shm_formats to a boolean and checks for the correct pixel
format it directly, instead of trying to gather them all in an array and
then later on to do the check.
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Trivial fix to clean itself on compositor tear-down. While at it
properly free the command string.
Fixes#298
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
With commit e825fe38, we no longer display the pointer if no movement is
detected, which will cause screen share to fail to start if that is the
case. There could be also legitimate cases where there's no pointer, so
let's allow screen share to function in those cases as well. Makes uses
of previous helper methods to find a proper output to share in case we
don't have an pointer.
Re-uses the shell utils functions.
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Input method process may also be a XIM server which requires the correct
DISPLAY to be set after xwayland start up. This helps input method to
work for both wayland and Xwayland.
Signed-off-by: Weng Xuetian <wengxt@gmail.com>
We want to wait for Xwayland to be ready before issuing it blocking
requests, but relying on USR1 is a bit unsafe:
- we can't ascertain the signal originated from Xwayland
- if weston is started as PID1 (e.g. in its own container), then
Xwayland will not send SIGUSR1 and X11 connections will be stuck
forever: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1312
Creating a pipe and using -displayfd, even if we don't care about the
display value itself, is safe and works for all cases
Signed-off-by: Dominique Martinet <dominique.martinet@atmark-techno.com>
The pixel format was hardcoded to PIXMAN_a8r8g8b8. All other
renderer->read_pixels() calls in weston use dynamic format selection via
the compositor->read_format instead.
The problem was spotted on the ARM devices with Mali-400 GPU. The visual
effect of the problem was black screen on the remote display, when using
screen-share with the VNC or RDP backends. Related wayland-devel thread:
https://lists.freedesktop.org/archives/wayland-devel/2020-September/041624.html
Signed-off-by: Maciej Pijanowski <maciej.pijanowski@3mdeb.com>
When we launch clients they currently stay in the same session as
weston, and share its controlling terminal. This means hitting ctrl-c
in weston's controlling terminal will send SIGINT to the clients as
well. It also means SIGHUP will be propagated to our launched clients
if weston's controlling terminal is closed.
While generally not harmful, this behaviour is not beneficial, and
is present by default and not by design.
Problems arise when launching weston in a debugger, as a ctrl-c sent to
the debugger will be propagated not only to the debugger, but all the child
processes sharing weston's session. This results in weston-desktop-shell
being killed by the ctrl-c that was intended to stop weston for debugging.
If weston-desktop-shell is killed within 30 second of startup, it will
result weston performing a clean shutdown. This clean shutdown can
make debugging a little too surprising.
Ostensibly, clients launched via weston_client_launch will be wayland
clients that terminate cleanly on their own if weston is killed, so
there should be no need for them to remain in weston's session to
catch ctrl-c from its controlling terminal. Nor should they need a
controlling terminal for their general operation.
Use setsid() to move them to their own session, devoid of controlling
terminal, to make using a debugger a little less confusing in some
cases.
Signed-off-by: Derek Foreman <derek.foreman@collabora.com>
signalfd interacts badly with gdb's signal trapping - when hitting
ctrl-c in a debugger attached to weston, weston will receive the
signal. This results in weston exiting cleanly when the intent
was to use gdb to interfere with its operation.
Trapping SIGINT was introduced in commit 50dc6989 which ensured we
would call wl_display_terminate() on SIGINT or SIGTERM to clean
up our socket.
Killing weston with SIGINT is quite common for several developers,
so it's important to preserve this clean shutdown behaviour, so
we can't naively stop trapping SIGINT entirely.
Instead, use the sigaction() function to trap SIGINT, and have
the SIGINT handler send weston SIGUSR2 (SIGUSR1 is already
used by xwayland). SIGUSR2 can be trapped in the proper wayland
way via wl_event_loop_add_signal(). This way we can properly
break our event loop and clean up on SIGINT, but we can also
have gdb intercept SIGINT.
There are other ways around this, but I'm hoping this one allows
people to continue using ctrl-c to stop weston, and doesn't
require additional project specific gdb knowledge.
Signed-off-by: Derek Foreman <derek.foreman@collabora.com>
We've been trapping SIGQUIT for a "clean shutdown" since commit 3cad436a
However, sources such as:
http://www.gnu.org/software/libc/manual/html_node/Termination-Signals.html
indicate we probably shouldn't be trapping it at all, as the intent of
SIGQUIT is to leave a core file and debug artifacts from the run.
We should perform the minimal amount of clean up to ensure the system isn't
left in an unusable state - but these days that's performed by other
software such as logind.
We can safely stop trapping SIGQUIT entirely.
Signed-off-by: Derek Foreman <derek.foreman@collabora.com>
We can use it just once to define a string instead of having preprocessor
conditionals sprinkled about the code.
Signed-off-by: Derek Foreman <derek.foreman@collabora.com>
We could overflow a local buffer if there were more than ten million
concurrently active displays within the current user's session. This
seems vanishingly unlikely, and harmless, but does at least squash a
compiler warning emitted by gcc 12+.
Signed-off-by: Daniel Stone <daniels@collabora.com>
Fbdev backend was deprecated in the Weston 10.0.0 release with
6338dbd581. Before that, I suggested
already in 2019 to remove it, but it was too soon then. Now it seems the
final voices asking for fbdev to be kept have been satisfied, see the
linked issue.
Fbdev-backend uses a kernel graphics UAPI (fbdev) which is sub-par for a
Wayland compositor: you cannot do GPU accelerated graphics in any
reasonable way, no hotplug support, multi-output support is tedious, and
so on. Most importantly, Linux has deprecated fbdev a long time ago due
to the UAPI fitting modern systems and use cases very poorly, but cannot
get rid of it if any users remain. Let's do here what we can to reduce
fbdev usage.
I am doing color management related additions to libweston which require
adding checks to every backend. One backend less is less churn to write
and review.
Libweston major version has already been bumped to 11, so the next
release will be Weston 11, without fbdev. enum weston_compositor_backend
entries change their numerical values.
Fixes: https://gitlab.freedesktop.org/wayland/weston/-/issues/581
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This doesn't work with any of the launchers we've kept. Remove the option
and all the bits that handle it.
Signed-off-by: Derek Foreman <derek.foreman@collabora.com>
Make it slightly easier to disambiguate clients when we log the protocol
stream from the server side.
Signed-off-by: Daniel Stone <daniels@collabora.com>
Name the seat created by the screen share plugin "screen-share" instead of
"default", to make it easier to recognize. No functional change intended.
Signed-off-by: Marek Vasut <marex@denx.de>
Derek Foreman
Daniel Stone
Pekka Paalanen
Michael Olbrich
Philipp Zabel
Hideyuki Nagase
Brenton DeGeer
Marius Vlad
Weng Xuetian
Dominique Martinet
Maciej Pijanowski
Marek Vasut