diff options
Diffstat (limited to 'nixos/modules/misc/crashdump.nix')
-rw-r--r-- | nixos/modules/misc/crashdump.nix | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/nixos/modules/misc/crashdump.nix b/nixos/modules/misc/crashdump.nix new file mode 100644 index 00000000000..b0f75d9caaa --- /dev/null +++ b/nixos/modules/misc/crashdump.nix @@ -0,0 +1,76 @@ +{ config, lib, pkgs, ... }: + +with lib; + +let + crashdump = config.boot.crashDump; + + kernelParams = concatStringsSep " " crashdump.kernelParams; + +in +###### interface +{ + options = { + boot = { + crashDump = { + enable = mkOption { + type = types.bool; + default = false; + description = '' + If enabled, NixOS will set up a kernel that will + boot on crash, and leave the user in systemd rescue + to be able to save the crashed kernel dump at + /proc/vmcore. + It also activates the NMI watchdog. + ''; + }; + reservedMemory = mkOption { + default = "128M"; + type = types.str; + description = '' + The amount of memory reserved for the crashdump kernel. + If you choose a too high value, dmesg will mention + "crashkernel reservation failed". + ''; + }; + kernelParams = mkOption { + type = types.listOf types.str; + default = [ "1" "boot.shell_on_fail" ]; + description = '' + Parameters that will be passed to the kernel kexec-ed on crash. + ''; + }; + }; + }; + }; + +###### implementation + + config = mkIf crashdump.enable { + boot = { + postBootCommands = '' + echo "loading crashdump kernel..."; + ${pkgs.kexec-tools}/sbin/kexec -p /run/current-system/kernel \ + --initrd=/run/current-system/initrd \ + --reset-vga --console-vga \ + --command-line="init=$(readlink -f /run/current-system/init) irqpoll maxcpus=1 reset_devices ${kernelParams}" + ''; + kernelParams = [ + "crashkernel=${crashdump.reservedMemory}" + "nmi_watchdog=panic" + "softlockup_panic=1" + ]; + kernelPatches = [ { + name = "crashdump-config"; + patch = null; + extraConfig = '' + CRASH_DUMP y + DEBUG_INFO y + PROC_VMCORE y + LOCKUP_DETECTOR y + HARDLOCKUP_DETECTOR y + ''; + } ]; + }; + }; +} |