Package: libwebkit2gtk-4.1-0 Version: 2.36.3-1 Followup-For: Bug #1012548 X-Debbugs-Cc: karogyoker2+deb...@gmail.com
Dear Maintainer, Please reopen this case because it turned out that it is not a hardware failure at all! I figured out everything about why epiphany is crashing for me, so this is what is happening: 1. Opening the Win10 ISO download page[1] tries to use offline rendering of Web Audio API 2. In DenormalDisabler.h stmxcsr is being called, it returns mxcsr's default value (0x1f80) 3. Then 0x1f80 is being OR-ed with 0x8040, that gives 0x9fc0 (it can be seen in eax) 4. In 0x9fc0 the 6th bit (0 based counting) is 1 5. ldmxcsr is being called with 0x9fc0 6. This gives a general protection fault because on 32 bit hardware the 6th bit is a reserved bit [2][3] 7. This is going to be a SIGSEGV on Linux (access violation on Windows) I thought that it is a hardware failure because on my other machine I didn't get an exception when I set the 6th bit to 1. But then I found these docs[2][3] and turned out that only real 32 bit CPUs are generating a GP (general protection fault). That's why it didn't crash for you in QEMU. QEMU's emulation is not implemented properly in this case. On my Haswell I can set the 6th bit to 1. It seems that in newer CPUs the 6th bit is not reserved anymore. Setting bits 16-31 are still generating a GP though. I think the solution is not to use the code where the ORing happens with 0x8040 (in case of i386 releases because this combination is not supported by hardware). For 32 bit CPUs the manual flushing must be used (the "FIXME: worst case" part in the code). I guess that deleting "defined(__i386__) || " from line #39 and #86 would solve the issue. I'll try to cross-compile WebKit on a faster PC (because on this one it would take ages) and test my hypothesis on real 32 bit hardware. [1]: https://www.microsoft.com/en-us/software-download/windows10ISO [2]: https://qcd.phys.cmu.edu/QCDcluster/intel/vtune/reference/vc148.htm [3]: https://help.totalview.io/previous_releases/2019/html/Reference_Guide/Intelx86MXSCRRegister_2.html -- System Information: Debian Release: bookworm/sid APT prefers testing-debug APT policy: (500, 'testing-debug'), (500, 'testing') Architecture: i386 (i686) Kernel: Linux 5.17.0-1-686-pae (SMP w/1 CPU thread; PREEMPT) Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en Shell: /bin/sh linked to /usr/bin/dash Init: systemd (via /run/systemd/system) LSM: AppArmor: enabled Versions of packages libwebkit2gtk-4.1-0 depends on: ii bubblewrap 0.6.2-1 ii gstreamer1.0-plugins-base 1.20.2-2 ii gstreamer1.0-plugins-good 1.20.2-1 ii libatk1.0-0 2.38.0-1 ii libc6 2.33-7 ii libcairo2 1.16.0-5 ii libegl1 1.4.0-1 ii libenchant-2-2 2.3.2-1 ii libfontconfig1 2.13.1-4.4 ii libfreetype6 2.12.1+dfsg-2 ii libgcc-s1 12.1.0-2 ii libgcrypt20 1.10.1-2 ii libgdk-pixbuf-2.0-0 2.42.8+dfsg-1 ii libglib2.0-0 2.72.1-1 ii libglx0 1.4.0-1 ii libgstreamer-gl1.0-0 1.20.2-2 ii libgstreamer-plugins-base1.0-0 1.20.2-2 ii libgstreamer1.0-0 1.20.2-1 ii libgtk-3-0 3.24.34-1 ii libharfbuzz-icu0 2.7.4-1+b1 ii libharfbuzz0b 2.7.4-1+b1 ii libhyphen0 2.8.8-7 ii libicu71 71.1-3 ii libjavascriptcoregtk-4.1-0 2.36.3-1 ii libjpeg62-turbo 1:2.1.2-1 ii liblcms2-2 2.12~rc1-2 ii libmanette-0.2-0 0.2.6-3 ii libnotify4 0.7.12-1 ii libopengl0 1.4.0-1 ii libopenjp2-7 2.4.0-6 ii libpango-1.0-0 1.50.7+ds-1 ii libpng16-16 1.6.37-5 ii libseccomp2 2.5.4-1 ii libsecret-1-0 0.20.5-2 ii libsoup-3.0-0 3.0.6-1 ii libsqlite3-0 3.38.5-1 ii libstdc++6 12.1.0-2 ii libsystemd0 250.4-1 ii libtasn1-6 4.18.0-4 ii libwayland-client0 1.20.0-1 ii libwayland-egl1 1.20.0-1 ii libwayland-server0 1.20.0-1 ii libwebp7 1.2.2-2+b1 ii libwebpdemux2 1.2.2-2+b1 ii libwoff1 1.0.2-1+b1 ii libwpe-1.0-1 1.12.0-1 ii libwpebackend-fdo-1.0-1 1.12.0-1 ii libx11-6 2:1.7.5-1 ii libxcomposite1 1:0.4.5-1 ii libxdamage1 1:1.1.5-2 ii libxml2 2.9.14+dfsg-1 ii libxslt1.1 1.1.34-4 ii xdg-dbus-proxy 0.1.4-1 ii zlib1g 1:1.2.11.dfsg-4 Versions of packages libwebkit2gtk-4.1-0 recommends: ii gstreamer1.0-gl 1.20.2-2 ii gstreamer1.0-libav 1.20.2-1 ii gstreamer1.0-plugins-bad 1.20.2-1 ii libgl1-mesa-dri 22.0.5-1 ii xdg-desktop-portal-gtk 1.14.0-1 Versions of packages libwebkit2gtk-4.1-0 suggests: ii gstreamer1.0-alsa 1.20.2-2 -- no debconf information
