Hi,
here's a libX11 patch that needs some wide testing, especially from
people who have experienced issues with various applications (fvwm[23]
from ports, Motif applications with Drag'n'Drop,..) with the upgrade
to libX11 1.8.1, before I added the --disable-thread-safety-constructor
option to the build.
This patch allows the callback functions from X*IfEvent() class of
Xlib functions to re-enter libX11, by making the
XlockDisplay()/XunlockDisplay() functions void while running the
callbacks.
I've tested fvwm2 with this patch and it seems to fix it (but since
the issue was never easy to reproduce I'm not 100% confident).
Please apply and report
cd /usr/xenocara/lib/libX11
patch -p0 -E < /path/to/this/patch
doas make -f Makefile.bsd-wrapper obj
doas make -f Makefile.bsd-wrapper build
Then restart X with the applications that where crashing last august.
Index: Makefile.bsd-wrapper
===================================================================
RCS file: /cvs/OpenBSD/xenocara/lib/libX11/Makefile.bsd-wrapper,v
retrieving revision 1.29
diff -u -p -u -r1.29 Makefile.bsd-wrapper
--- Makefile.bsd-wrapper 3 Sep 2022 06:55:25 -0000 1.29
+++ Makefile.bsd-wrapper 1 Nov 2022 09:21:34 -0000
@@ -14,7 +14,6 @@ SHARED_LIBS= X11 18.0 X11_xcb 2.0
CONFIGURE_ARGS= --enable-tcp-transport --enable-unix-transport --enable-ipv6 \
--disable-composecache \
- --disable-thread-safety-constructor \
--without-xmlto --without-fop --without-xsltproc
.include <bsd.xorg.mk>
Index: include/X11/Xlibint.h
===================================================================
RCS file: /cvs/OpenBSD/xenocara/lib/libX11/include/X11/Xlibint.h,v
retrieving revision 1.15
diff -u -p -u -r1.15 Xlibint.h
--- include/X11/Xlibint.h 21 Feb 2022 08:01:24 -0000 1.15
+++ include/X11/Xlibint.h 1 Nov 2022 09:21:34 -0000
@@ -207,6 +207,7 @@ struct _XDisplay
XIOErrorExitHandler exit_handler;
void *exit_handler_data;
+ Bool in_ifevent;
};
#define XAllocIDs(dpy,ids,n) (*(dpy)->idlist_alloc)(dpy,ids,n)
Index: src/ChkIfEv.c
===================================================================
RCS file: /cvs/OpenBSD/xenocara/lib/libX11/src/ChkIfEv.c,v
retrieving revision 1.4
diff -u -p -u -r1.4 ChkIfEv.c
--- src/ChkIfEv.c 30 May 2011 19:19:38 -0000 1.4
+++ src/ChkIfEv.c 1 Nov 2022 09:21:35 -0000
@@ -50,6 +50,7 @@ Bool XCheckIfEvent (
int n; /* time through count */
LockDisplay(dpy);
+ dpy->in_ifevent = True;
prev = NULL;
for (n = 3; --n >= 0;) {
for (qelt = prev ? prev->next : dpy->head;
@@ -60,6 +61,7 @@ Bool XCheckIfEvent (
*event = qelt->event;
_XDeq(dpy, prev, qelt);
_XStoreEventCookie(dpy, event);
+ dpy->in_ifevent = False;
UnlockDisplay(dpy);
return True;
}
@@ -78,6 +80,7 @@ Bool XCheckIfEvent (
/* another thread has snatched this event */
prev = NULL;
}
+ dpy->in_ifevent = False;
UnlockDisplay(dpy);
return False;
}
Index: src/IfEvent.c
===================================================================
RCS file: /cvs/OpenBSD/xenocara/lib/libX11/src/IfEvent.c,v
retrieving revision 1.4
diff -u -p -u -r1.4 IfEvent.c
--- src/IfEvent.c 30 May 2011 19:19:38 -0000 1.4
+++ src/IfEvent.c 1 Nov 2022 09:21:35 -0000
@@ -49,6 +49,7 @@ XIfEvent (
unsigned long qe_serial = 0;
LockDisplay(dpy);
+ dpy->in_ifevent = True;
prev = NULL;
while (1) {
for (qelt = prev ? prev->next : dpy->head;
@@ -59,6 +60,7 @@ XIfEvent (
*event = qelt->event;
_XDeq(dpy, prev, qelt);
_XStoreEventCookie(dpy, event);
+ dpy->in_ifevent = False;
UnlockDisplay(dpy);
return 0;
}
Index: src/OpenDis.c
===================================================================
RCS file: /cvs/OpenBSD/xenocara/lib/libX11/src/OpenDis.c,v
retrieving revision 1.12
diff -u -p -u -r1.12 OpenDis.c
--- src/OpenDis.c 28 Nov 2020 14:39:48 -0000 1.12
+++ src/OpenDis.c 1 Nov 2022 09:21:35 -0000
@@ -189,6 +189,7 @@ XOpenDisplay (
dpy->xcmisc_opcode = 0;
dpy->xkb_info = NULL;
dpy->exit_handler_data = NULL;
+ dpy->in_ifevent = False;
/*
* Setup other information in this display structure.
Index: src/PeekIfEv.c
===================================================================
RCS file: /cvs/OpenBSD/xenocara/lib/libX11/src/PeekIfEv.c,v
retrieving revision 1.3
diff -u -p -u -r1.3 PeekIfEv.c
--- src/PeekIfEv.c 30 May 2011 19:19:38 -0000 1.3
+++ src/PeekIfEv.c 1 Nov 2022 09:21:35 -0000
@@ -50,6 +50,7 @@ XPeekIfEvent (
unsigned long qe_serial = 0;
LockDisplay(dpy);
+ dpy->in_ifevent = True;
prev = NULL;
while (1) {
for (qelt = prev ? prev->next : dpy->head;
@@ -63,6 +64,7 @@ XPeekIfEvent (
_XStoreEventCookie(dpy, ©);
*event = copy;
}
+ dpy->in_ifevent = False;
UnlockDisplay(dpy);
return 0;
}
Index: src/locking.c
===================================================================
RCS file: /cvs/OpenBSD/xenocara/lib/libX11/src/locking.c,v
retrieving revision 1.8
diff -u -p -u -r1.8 locking.c
--- src/locking.c 28 Nov 2020 14:39:48 -0000 1.8
+++ src/locking.c 1 Nov 2022 09:21:35 -0000
@@ -455,6 +455,32 @@ static void _XDisplayLockWait(
static void _XLockDisplay(
Display *dpy
XTHREADS_FILE_LINE_ARGS
+ );
+
+static void _XIfEventLockDisplay(
+ Display *dpy
+ XTHREADS_FILE_LINE_ARGS
+ )
+{
+ /* assert(dpy->in_ifevent); */
+}
+
+static void _XIfEventUnlockDisplay(
+ Display *dpy
+ XTHREADS_FILE_LINE_ARGS
+ )
+{
+ if (dpy->in_ifevent)
+ return;
+
+ dpy->lock_fns->lock_display = _XLockDisplay;
+ dpy->lock_fns->unlock_display = _XUnlockDisplay;
+ UnlockDisplay(dpy);
+}
+
+static void _XLockDisplay(
+ Display *dpy
+ XTHREADS_FILE_LINE_ARGS
)
{
#ifdef XTHREADS
@@ -478,6 +504,10 @@ static void _XLockDisplay(
#endif
_XIDHandler(dpy);
_XSeqSyncFunction(dpy);
+ if (dpy->in_ifevent) {
+ dpy->lock_fns->lock_display = _XIfEventLockDisplay;
+ dpy->lock_fns->unlock_display = _XIfEventUnlockDisplay;
+ }
}
/*
--
Matthieu Herrb
