Bug 282172 – [GTK] [2.46.2] WebCore::DisplayUpdate::nextUpdate(): Arithmetic exception on i386

• Status: NEW
• Component: WebKitGTK

[Alberto Garcia]

One Debian user reports the following crash using WebKitGTK 2.46.0 and 2.46.2 in i386 when running Evolution 3.54.0 on Debian trixie:

Thread 48 "VBlankMonitor" received signal SIGFPE, Arithmetic exception.
[Switching to Thread 0xccc7bb40 (LWP 21804)]
Download failed: Argument invalide.  Continuing without source file ./build-soup3/./build-soup3/WebCore/PrivateHeaders/WebCore/DisplayUpdate.h.
WebCore::DisplayUpdate::nextUpdate () at ./build-soup3/WebCore/PrivateHeaders/WebCore/DisplayUpdate.h:44
warning: 44	./build-soup3/WebCore/PrivateHeaders/WebCore/DisplayUpdate.h: Aucun fichier ou dossier de ce nom
#0  WebCore::DisplayUpdate::nextUpdate () at ./build-soup3/WebCore/PrivateHeaders/WebCore/DisplayUpdate.h:44
#1  WebKit::DisplayLink::notifyObserversDisplayDidRefresh () at ./Source/WebKit/UIProcess/DisplayLink.cpp:217
#2  0xf1f734db in operator() () at ./Source/WebKit/UIProcess/glib/DisplayLinkGLib.cpp:38
#3  call () at ./build-soup3/WTF/Headers/wtf/Function.h:53
#4  0xf1f73bbc in WTF::Function<void()>::operator() () at ./build-soup3/WTF/Headers/wtf/Function.h:82
#5  operator() () at ./Source/WebKit/UIProcess/glib/DisplayVBlankMonitor.cpp:101
#6  call () at ./build-soup3/WTF/Headers/wtf/Function.h:53
#7  0xeeca1d20 in WTF::Function<void()>::operator() () at ./Source/WTF/wtf/Function.h:82
#8  WTF::Thread::entryPoint () at ./Source/WTF/wtf/Threading.cpp:266
#9  0xeed0a9f8 in wtfThreadEntryPoint () at ./Source/WTF/wtf/posix/ThreadingPOSIX.cpp:239
#10 0xf0dda872 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:447
#11 0xf0e72b48 in __GI___clone3 () at ../sysdeps/unix/sysv/linux/i386/clone3.S:111

From the line numbers the problem seems to be here: https://github.com/WebKit/WebKit/blob/webkitgtk-2.46.2/Source/WebCore/platform/graphics/DisplayUpdate.h#L44

And that is likely a division by zero:

    DisplayUpdate nextUpdate() const
    {
        return { (updateIndex + 1) % updatesPerSecond, updatesPerSecond };
    }

The CPU is an Intel Core2 Duo T9300