Bug 78706

Created attachment 99043 [details]
gdb-backtrace

When weston client is in fullscreen mode,  touching the display while close/destroy animation is performing causes weston crash.   Touch events during fullscreened client close animation, leads to segmentation fault in wl_resource_get_client. 

Another way to reproduce this issue is:
1. Launch weston-terminal
2. Enter fullscreen via <f11>
3. Press <mod> + k 
4. Touch the display while close animation is performing. Observe weston crash.


This is an issue under below software stack as well.
wayland (HEAD) 1.5.0-0-g3ac62cd
drm (HEAD) libdrm-2.4.54-0-g5126fcb
mesa (HEAD) mesa-10.1.3-0-g0028eb1
libva (HEAD) libva-1.2.1-0-g88ed1eb
intel-driver (HEAD) 1.2.2-0-g121e70d
cairo (HEAD) 1.12.16-0-g8e11a42
weston (HEAD) 1.5.0-0-g8801936

Created attachment 105304 [details] [review]
Stop crash when starting a touch during a fullscreen fade

This issue is still reproducible today - I think this patch fixes it, but is only partially tested because I don't have a touchscreen (I just mashed up libinput to pretend my mouse is one).

If you could test and confirm this works, that would be great.

(In reply to comment #3)
> Created attachment 105304 [details] [review] [review]
> Stop crash when starting a touch during a fullscreen fade
> 
> This issue is still reproducible today - I think this patch fixes it, but is
> only partially tested because I don't have a touchscreen (I just mashed up
> libinput to pretend my mouse is one).
> 
> If you could test and confirm this works, that would be great.

Looks good, although I don't have a touchscreen to test either.

One little question here: can we use
if (find_resource_for_view(&seat->touch->resource_list, view)) instead of
if (view)
to avoid the problem just as weston_pointer_set_focus do it?

If that can be used, the code will be much cleaner.

I also suggest sending the patch to the mailing list for review.

Will try that and send the resulting patch to the list later today,
thanks

I've posted a slightly changed version of this patch to the list that also stops another segfault (mod-touch during the fadeout would still crash even though just touching didn't)

I don't think find_resource_for_view() helps, as it does a few additional checks.  A direct substitution prevents the icons at the top of the screen from working.

I tested Derek’s patch from wayland-devel( http://lists.freedesktop.org/archives/wayland-devel/2014-August/016978.html) on touch screen with below s/s. This patch fixes Segfault in weston. So, it can be merged.

Software Stack
wayland (HEAD) remotes/origin/HEAD-0-g6d0f298 
drm (HEAD) heads/master-16-gd686160 
mesa (HEAD) remotes/origin/10.2-0-gd82ca4e 
libva (HEAD) libva-1.3.1-0-g053f70f 
intel-driver (HEAD) 1.3.1-0-ga720bc8 
cairo (HEAD) heads/1.12-0-g59e2a93 
libinput (HEAD) heads/master-163-gbb10ec8 
weston (HEAD) remotes/origin/master-0-g652c794

Should be fixed by:

commit 362656bfa308b653ed6c40b3e788b481d92b7cc8
Author: Derek Foreman <derekf@osg.samsung.com>
Date:   Thu Sep 4 10:23:05 2014 -0500

    touch-input: Don't dereference NULL pointer during full screen fade