Hi Ubuntu users! Signal 7 is SIGBUS. SIGBUS should be relatively unusual on x86 [1].
[1] https://stackoverflow.com/questions/2089167/debugging-sigbus- on-x86-linux I'm excited to inform you that Fedora Linux users also started seeing the same root problem. It is tied to the upgrade from kernel v4.14 to v4.15. Fedora bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1553979 Arch Linux independently identified this as caused by the kernel upgrade: https://bbs.archlinux.org/viewtopic.php?id=235027 It can happen after resume from suspend, not every time but maybe once every three days. We have reports for both Xwayland and Xorg getting a fatal SIGBUS in _dl_fixup(). (While this is actually a secondary crash in xorg_backtrace(), we have a load of SIGBUS traces that have the same primary trace as each other). Notice the specific faulting instruction in disassembly you captured: it is not performing a memory access! => 0x559c102a4060 <ErrorFSigSafe>: sub $0xd8,%rsp Instead, notice that this is the first instruction in the function ErrorFSigSafe. This is a big common factor in our traces. (We actually have several different traces captured, with the failing function varying, often along the same call chain). What's happening is a fault on the instruction fetch. You should be able to confirm this if you look at the address which generates the fault. (si_addr field of struct siginfo. I don't know where the Ubuntu crash collector saves this information) The kernel failed to load in the page which holds the program code at this point. That's the real problem: some sort of transient IO error during wakeup. Users sometimes see other symptoms of these IO errors as well: PM: resume devices took 1.017 seconds Restarting tasks ... Read-error on swap-device (253:1:836184) PM: suspend exit systemd-coredump[755]: Process 1356 (Xwayland) of user 42 dumped core. and PM: suspend exit EXT4-fs error (device dm-2): ext4_find_entry:1436: inode #5514052: comm thunderbird: reading directory lblock 0 Buffer I/O error on dev dm-2, logical block 0, lost sync page write WARNING: CPU: 1 PID: 748 at fs/buffer.c:1108 mark_buffer_dirty+0xd4/0xe0 (and a kernel backtrace) ** Bug watch added: Red Hat Bugzilla #1553979 https://bugzilla.redhat.com/show_bug.cgi?id=1553979 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1760450 Title: Xorg crashed with signal 7 in _dl_fixup() Status in xorg-server package in Ubuntu: New Bug description: after login session(suspend mode) ProblemType: Crash DistroRelease: Ubuntu 18.04 Package: xserver-xorg-core 2:1.19.6-1ubuntu3 ProcVersionSignature: Ubuntu 4.15.0-13.14-generic 4.15.10 Uname: Linux 4.15.0-13-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.20.9-0ubuntu2 Architecture: amd64 Date: Sun Apr 1 20:34:29 2018 DistroCodename: bionic DistroVariant: ubuntu ExecutablePath: /usr/lib/xorg/Xorg InstallationDate: Installed on 2017-09-02 (211 days ago) InstallationMedia: Ubuntu-GNOME 17.04 "Zesty Zapus" - Release amd64 (20170412) ProcCmdline: /usr/lib/xorg/Xorg vt2 -displayfd 3 -auth /run/user/1000/gdm/Xauthority -background none -noreset -keeptty -verbose 3 ProcEnviron: Signal: 7 SourcePackage: xorg-server StacktraceTop: _dl_fixup (l=0x559c10faa5a0, reloc_arg=<optimized out>) at ../elf/dl-runtime.c:84 _dl_runtime_resolve_xsavec () at ../sysdeps/x86_64/dl-trampoline.h:125 ?? () from /usr/lib/xorg/modules/libwfb.so wfbComposite () from /usr/lib/xorg/modules/libwfb.so ?? () from /usr/lib/x86_64-linux-gnu/nvidia/xorg/nvidia_drv.so Title: Xorg crashed with signal 7 in _dl_fixup() UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip libvirt lpadmin plugdev sambashare sudo To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1760450/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
