Do not abort when releasing an unlocked mutex

Backport an upstream fix to avoid triggering abort() from F21 glib2 when
releasing a mutex that hasn't been locked yet.

https://bugzilla.redhat.com/show_bug.cgi?id=1138146
This commit is contained in:
Kalev Lember 2014-09-04 13:23:07 +02:00
parent c3acd62c32
commit df9ee1c1d9
2 changed files with 94 additions and 1 deletions

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@ -0,0 +1,88 @@
From fbf38d16bcc26630f0f721d266509f5bc292f606 Mon Sep 17 00:00:00 2001
From: Emmanuele Bassi <ebassi@gnome.org>
Date: Tue, 26 Aug 2014 12:07:34 +0100
Subject: [PATCH] threads: Do not release the GDK lock if it hasn't been
acquired yet
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Since GLib ≥ 2.41, attempting to release an unlocked mutex will abort(),
as it happens on most systems already.
Given the lack of proper documentation on how to use GDK with threads,
there is code in the wild that does:
gdk_threads_init ();
gdk_init ();
...
gtk_main ();
instead of the idiomatically correct:
gdk_threads_init ();
gdk_threads_enter ();
gtk_init ();
...
gtk_main ();
...
gdk_threads_leave ();
Which means that gtk_main() will try to release the GDK lock, and thus
trigger an error from GLib.
we cannot really fix all the wrong code everywhere, and since it does
not cost us anything, we can work around the issue inside GDK itself, by
trying to acquire the GDK lock inside gdk_threads_leave() with
trylock().
https://bugzilla.gnome.org/show_bug.cgi?id=735428
---
gdk/gdk.c | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/gdk/gdk.c b/gdk/gdk.c
index 0106d8a..f722dbf 100644
--- a/gdk/gdk.c
+++ b/gdk/gdk.c
@@ -434,7 +434,29 @@ static void
gdk_threads_impl_unlock (void)
{
if (gdk_threads_mutex)
- g_mutex_unlock (gdk_threads_mutex);
+ {
+ /* we need a trylock() here because trying to unlock a mutex
+ * that hasn't been locked yet is:
+ *
+ * a) not portable
+ * b) fail on GLib ≥ 2.41
+ *
+ * trylock() will either succeed because nothing is holding the
+ * GDK mutex, and will be unlocked right afterwards; or it's
+ * going to fail because the mutex is locked already, in which
+ * case we unlock it as expected.
+ *
+ * this is needed in the case somebody called gdk_threads_init()
+ * without calling gdk_threads_enter() before calling gtk_main().
+ * in theory, we could just say that this is undefined behaviour,
+ * but our documentation has always been *less* than explicit as
+ * to what the behaviour should actually be.
+ *
+ * see bug: https://bugzilla.gnome.org/show_bug.cgi?id=735428
+ */
+ g_mutex_trylock (gdk_threads_mutex);
+ g_mutex_unlock (gdk_threads_mutex);
+ }
}
/**
--
2.1.0

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@ -18,7 +18,7 @@
Summary: The GIMP ToolKit (GTK+), a library for creating GUIs for X Summary: The GIMP ToolKit (GTK+), a library for creating GUIs for X
Name: gtk2 Name: gtk2
Version: 2.24.24 Version: 2.24.24
Release: 2%{?dist} Release: 3%{?dist}
License: LGPLv2+ License: LGPLv2+
Group: System Environment/Libraries Group: System Environment/Libraries
URL: http://www.gtk.org URL: http://www.gtk.org
@ -35,6 +35,7 @@ Patch2: icon-padding.patch
Patch8: tooltip-positioning.patch Patch8: tooltip-positioning.patch
# https://bugzilla.gnome.org/show_bug.cgi?id=611313 # https://bugzilla.gnome.org/show_bug.cgi?id=611313
Patch15: window-dragging.patch Patch15: window-dragging.patch
Patch16: 0001-threads-Do-not-release-the-GDK-lock-if-it-hasn-t-bee.patch
BuildRequires: atk-devel >= %{atk_version} BuildRequires: atk-devel >= %{atk_version}
BuildRequires: glib2-devel >= %{glib2_version} BuildRequires: glib2-devel >= %{glib2_version}
@ -146,6 +147,7 @@ This package contains developer documentation for the GTK+ widget toolkit.
%patch2 -p1 -b .icon-padding %patch2 -p1 -b .icon-padding
%patch8 -p1 -b .tooltip-positioning %patch8 -p1 -b .tooltip-positioning
%patch15 -p1 -b .window-dragging %patch15 -p1 -b .window-dragging
%patch16 -p1 -b .trylock
%build %build
(if ! test -x configure; then NOCONFIGURE=1 ./autogen.sh; CONFIGFLAGS=--enable-gtk-doc; fi; (if ! test -x configure; then NOCONFIGURE=1 ./autogen.sh; CONFIGFLAGS=--enable-gtk-doc; fi;
@ -335,6 +337,9 @@ gtk-query-immodules-2.0-%{__isa_bits} --update-cache
%doc tmpdocs/examples %doc tmpdocs/examples
%changelog %changelog
* Thu Sep 04 2014 Kalev Lember <kalevlember@gmail.com> - 2.24.24-3
- Do not abort when releasing an unlocked mutex (#1138146)
* Sat Aug 16 2014 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 2.24.24-2 * Sat Aug 16 2014 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 2.24.24-2
- Rebuilt for https://fedoraproject.org/wiki/Fedora_21_22_Mass_Rebuild - Rebuilt for https://fedoraproject.org/wiki/Fedora_21_22_Mass_Rebuild