From d674e773afec7568a84545d10eb3e4100aaf4d9f Mon Sep 17 00:00:00 2001 From: V3n3RiX Date: Fri, 9 Sep 2022 18:55:58 +0100 Subject: x11-libs/libX11 : bugfix ( https://gitlab.freedesktop.org/xorg/lib/libx11/-/issues/157 ) --- x11-libs/libX11/files/150.patch | 175 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 175 insertions(+) create mode 100644 x11-libs/libX11/files/150.patch (limited to 'x11-libs/libX11/files') diff --git a/x11-libs/libX11/files/150.patch b/x11-libs/libX11/files/150.patch new file mode 100644 index 00000000..1c3b6bd7 --- /dev/null +++ b/x11-libs/libX11/files/150.patch @@ -0,0 +1,175 @@ +From 8808d16b0bc53e6c1e235d2fc714145b9adcf626 Mon Sep 17 00:00:00 2001 +From: Adam Jackson +Date: Fri, 5 Aug 2022 15:19:08 -0400 +Subject: [PATCH] Allow X*IfEvent() to reenter libX11 + +The documentation for this family of functions very clearly says not to +call into xlib in your predicate function, but historically single +threaded apps could get away with it just fine, and now that we've +forced thread-safety on the world such apps will now deadlock instead. +That's not an acceptable regression even if the app is technically +broken. This has been reported with XFCE and FVWM, and Motif's +cut-and-paste code has the same bug by inspection, so this does need to +be addressed. + +This change nerfs LockDisplay/UnlockDisplay while inside the critical +bit of an IfEvent function. This is still safe in the sense that the +display remains locked and no other thread should be able to change it +from under us, but the loop that scans the event queue might not be +robust against it being modified as a side effect of protocol emitted by +the predicate callback. But that's not new, non-XInitThreads'd xlib +would have the same caveat. + +Closes: xorg/lib/libx11#157 +--- + include/X11/Xlibint.h | 1 + + src/ChkIfEv.c | 3 +++ + src/IfEvent.c | 2 ++ + src/OpenDis.c | 1 + + src/PeekIfEv.c | 2 ++ + src/locking.c | 30 ++++++++++++++++++++++++++++++ + 6 files changed, 39 insertions(+) + +diff --git a/include/X11/Xlibint.h b/include/X11/Xlibint.h +index 6d880a65..46c9ac11 100644 +--- a/include/X11/Xlibint.h ++++ b/include/X11/Xlibint.h +@@ -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) +diff --git a/src/ChkIfEv.c b/src/ChkIfEv.c +index 876a850e..327b5eaf 100644 +--- a/src/ChkIfEv.c ++++ b/src/ChkIfEv.c +@@ -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; + } +diff --git a/src/IfEvent.c b/src/IfEvent.c +index ead93dca..a0aed7e3 100644 +--- a/src/IfEvent.c ++++ b/src/IfEvent.c +@@ -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; + } +diff --git a/src/OpenDis.c b/src/OpenDis.c +index 5017b040..e1bc2a30 100644 +--- a/src/OpenDis.c ++++ b/src/OpenDis.c +@@ -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. +diff --git a/src/PeekIfEv.c b/src/PeekIfEv.c +index 207cd119..c4e8af0d 100644 +--- a/src/PeekIfEv.c ++++ b/src/PeekIfEv.c +@@ -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; + } +diff --git a/src/locking.c b/src/locking.c +index ea5000e1..36530691 100644 +--- a/src/locking.c ++++ b/src/locking.c +@@ -452,6 +452,32 @@ 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 +@@ -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; ++ } + } + + /* +-- +GitLab + -- cgit v1.2.3