Keep track of panic sysctls in the kdump-steamos package

Before this patch, the sysctl parameters for panic on oops, lockups, etc
were tracked in the "image-recipes/jupiter" gitlab repositories. After
MR [0] this changed and now we must keep track of the sysctls inside
the kdump-steamos package.

Hence, this commit adds the sysctl config file into "/usr/lib/sysctl.d",
also introducing the "panic_print" sysctl, to enable dumping more info
on panic events.

[0] https://gitlab.steamos.cloud/jupiter/jupiter/-/merge_requests/1

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>

20-kdump-steamos.conf

@@ -0,0 +1,31 @@
+#  SPDX-License-Identifier: LGPL-2.1+
+#
+#  Copyright (c) 2022 Valve.
+#  Maintainer: Guilherme G. Piccoli <gpiccoli@igalia.com>
+#
+#  This file sets the sysctl parameters that are used by the
+#  kdump-steamos package, in order to panic and reboot on
+#  severe events, like oops or soft/hard lockups.
+#  Also, we set panic_print in order to collect more info.
+
+kernel.panic_on_oops = 1
+
+kernel.panic_on_rcu_stall = 1
+
+kernel.softlockup_panic = 1
+
+kernel.hardlockup_panic = 1
+
+#  reboot as soon as possible after a panic event.
+kernel.panic = -1
+
+#  dump more information when facing a panic event:
+#  bit 0 - print all tasks info
+#  bit 1 - print system memory info
+#  bit 2 - print timer info
+#  bit 6 - print all CPUs backtrace (currently on linux-next)
+kernel.panic_print = 71
+
+#  Currently disabled, since SteamOS might get stuck while
+#  doing installation on drive using calamares.
+kernel.hung_task_panic = 0