[rpms/glib2] cve-2026-58016-f44: Backport a gmain GWakeup patch to fix timedatex high CPU usage

[Kalev Lember <klember@redhat.com>]

            A new commit has been pushed.

            Repo   : rpms/glib2
            Branch : cve-2026-58016-f44
            Commit : 15854645a451f349662f7de7d6dae2fa86c84cd2
            Author : Kalev Lember <klember@redhat.com>
            Date   : 2017-05-15T10:54:10+02:00
            Stats  : +113/-1 in 2 file(s)
            URL    : https://src.fedoraproject.org/rpms/glib2/c/15854645a451f349662f7de7d6dae2fa86c84cd2?branch=cve-2026-58016-f44

            Log:
            Backport a gmain GWakeup patch to fix timedatex high CPU usage

https://bugzilla.redhat.com/show_bug.cgi?id=1450628

---
diff --git a/0001-gmain-only-signal-GWakeup-right-before-or-during-a-b.patch b/0001-gmain-only-signal-GWakeup-right-before-or-during-a-b.patch
new file mode 100644
index 0000000..400645b
--- /dev/null
+++ b/0001-gmain-only-signal-GWakeup-right-before-or-during-a-b.patch
@@ -0,0 +1,106 @@
+From 5d74233476d61771b4d67d50bec5420f551ef922 Mon Sep 17 00:00:00 2001
+From: Paolo Bonzini <pbonzini@redhat.com>
+Date: Tue, 4 Apr 2017 09:56:47 +0200
+Subject: [PATCH] gmain: only signal GWakeup right before or during a blocking
+ poll
+
+Since commit e4ee307 ("Do not wake up main loop if change is from same
+thread", bug 761102), GMainContext uses context->owner to decide if the
+event loop is being run in the current thread.  However, what really
+matters is the phase in the prepare/query/poll/check/dispatch sequence.
+Wakeups are only needed between the end of prepare and the end of poll,
+and then only if prepare found that no sources were ready.
+
+There is no need to take threads into account, because prepare, check
+and all callers of conditional_wakeup all look at the new need_wakeup
+flag inside LOCK_CONTEXT/UNLOCK_CONTEXT.
+
+With this change, g_main_context_is_owner and g_main_context_wait are
+the only functions for which acquire/release matters, just like before
+commit e4ee307.
+
+Signed-off-by: Paolo Bonzini <bonzini@gnu.org>
+---
+ glib/gmain.c | 30 +++++++++++++++++++-----------
+ 1 file changed, 19 insertions(+), 11 deletions(-)
+
+diff --git a/glib/gmain.c b/glib/gmain.c
+index ab2908e52..af0a29ae5 100644
+--- a/glib/gmain.c
++++ b/glib/gmain.c
+@@ -277,7 +277,8 @@ struct _GMainContext
+ 
+   guint next_id;
+   GList *source_lists;
+-  gint in_check_or_prepare;
++  gboolean in_check_or_prepare;
++  gboolean need_wakeup;
+ 
+   GPollRec *poll_records;
+   guint n_poll_records;
+@@ -651,6 +652,7 @@ g_main_context_new (void)
+   
+   context->pending_dispatches = g_ptr_array_new ();
+   
++  context->need_wakeup = FALSE;
+   context->time_is_fresh = FALSE;
+   
+   context->wakeup = g_wakeup_new ();
+@@ -1127,17 +1129,11 @@ source_remove_from_context (GSource      *source,
+ static void
+ conditional_wakeup (GMainContext *context)
+ {
+-  /* We want to signal wakeups in two cases:
+-   *  1 When the context is owned by another thread
+-   *  2 When the context owner is NULL (two subcases)
+-   *   2a Possible if the context has never been acquired
+-   *   2b Or if the context has no current owner
+-   *
+-   * At least case 2a) is necessary to ensure backwards compatibility with
+-   * qemu's use of GMainContext.
+-   * https://bugzilla.gnome.org/show_bug.cgi?id=761102#c14
++  /* This flag is set if at the start of prepare() we have no other ready
++   * sources, and hence would wait in poll(). In that case, any other threads
++   * attaching sources will need to signal a wakeup.
+    */
+-  if (context->owner != G_THREAD_SELF)
++  if (context->need_wakeup)
+     g_wakeup_signal (context->wakeup);
+ }
+ 
+@@ -3469,6 +3465,10 @@ g_main_context_prepare (GMainContext *context,
+   
+   LOCK_CONTEXT (context);
+ 
++  /* context->need_wakeup is protected by LOCK_CONTEXT/UNLOCK_CONTEXT,
++   * so need not set it yet.
++   */
++
+   context->time_is_fresh = FALSE;
+ 
+   if (context->in_check_or_prepare)
+@@ -3594,6 +3594,8 @@ g_main_context_prepare (GMainContext *context,
+ 	}
+     }
+   g_source_iter_clear (&iter);
++  /* See conditional_wakeup() where this is used */
++  context->need_wakeup = (n_ready == 0);
+ 
+   TRACE (GLIB_MAIN_CONTEXT_AFTER_PREPARE (context, current_priority, n_ready));
+ 
+@@ -3728,6 +3730,12 @@ g_main_context_check (GMainContext *context,
+ 
+   TRACE (GLIB_MAIN_CONTEXT_BEFORE_CHECK (context, max_priority, fds, n_fds));
+ 
++  /* We don't need to wakeup during check or dispatch, because
++   * all sources will be re-evaluated during prepare/query.
++   */
++  context->need_wakeup = FALSE;
++
++  /* And if we have a wakeup pending, acknowledge it */
+   for (i = 0; i < n_fds; i++)
+     {
+       if (fds[i].fd == context->wake_up_rec.fd)
+-- 
+2.12.2
+

diff --git a/glib2.spec b/glib2.spec
index 1efc9ea..9f3dc7c 100644
--- a/glib2.spec
+++ b/glib2.spec
@@ -5,13 +5,15 @@
 
 Name: glib2
 Version: 2.52.2
-Release: 1%{?dist}
+Release: 2%{?dist}
 Summary: A library of handy utility functions
 
 License: LGPLv2+
 URL: http://www.gtk.org
 Source0: http://download.gnome.org/sources/glib/2.52/glib-%{version}.tar.xz
 
+Patch0: 0001-gmain-only-signal-GWakeup-right-before-or-during-a-b.patch
+
 BuildRequires: chrpath
 BuildRequires: gettext
 BuildRequires: perl-generators
@@ -81,6 +83,7 @@ the functionality of the installed glib2 package.
 
 %prep
 %setup -q -n glib-%{version}
+%patch0 -p1
 
 %build
 # Bug 1324770: Also explicitly remove PCRE sources since we use --with-pcre=system
@@ -229,6 +232,9 @@ glib-compile-schemas %{_datadir}/glib-2.0/schemas &> /dev/null || :
 %{_datadir}/installed-tests
 
 %changelog
+* Mon May 15 2017 Kalev Lember <klember@redhat.com> - 2.52.2-2
+- Backport a gmain GWakeup patch to fix timedatex high CPU usage (#1450628)
+
 * Tue May 09 2017 Kalev Lember <klember@redhat.com> - 2.52.2-1
 - Update to 2.52.2