kevin/linux
1
Fork 0
Code

watchdog: move softlockup_panic back to early_param

Browse Source 
Setting softlockup_panic from do_sysctl_args() causes it to take effect
later in boot.  The lockup detector is enabled before SMP is brought
online, but do_sysctl_args runs afterwards.  If a user wants to set
softlockup_panic on boot and have it trigger should a softlockup occur
during onlining of the non-boot processors, they could do this prior to
commit f117955a22 ("kernel/watchdog.c: convert {soft/hard}lockup boot
parameters to sysctl aliases").  However, after this commit the value
of softlockup_panic is set too late to be of help for this type of
problem.  Restore the prior behavior.

Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Cc: stable@vger.kernel.org
Fixes: f117955a22 ("kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases")
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
This commit is contained in:
Krister Johansen 2023-10-27 14:46:53 -07:00 committed by Luis Chamberlain
parent 8001f49394
commit 8b793bcda6
2 changed files with 7 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
fs/proc/proc_sysctl.c
View File

@ -1576,7 +1576,6 @@ static const struct sysctl_alias sysctl_aliases[] = {
{"hung_task_panic", "kernel.hung_task_panic" }, {"hung_task_panic", "kernel.hung_task_panic" },
{"numa_zonelist_order", "vm.numa_zonelist_order" }, {"numa_zonelist_order", "vm.numa_zonelist_order" },
{"softlockup_all_cpu_backtrace", "kernel.softlockup_all_cpu_backtrace" }, {"softlockup_all_cpu_backtrace", "kernel.softlockup_all_cpu_backtrace" },
{"softlockup_panic", "kernel.softlockup_panic" },
{ } { }
}; };

7
kernel/watchdog.c
View File

@ -283,6 +283,13 @@ static DEFINE_PER_CPU(struct hrtimer, watchdog_hrtimer);
static DEFINE_PER_CPU(bool, softlockup_touch_sync); static DEFINE_PER_CPU(bool, softlockup_touch_sync);
static unsigned long soft_lockup_nmi_warn; static unsigned long soft_lockup_nmi_warn;
static int __init softlockup_panic_setup(char *str)
{
softlockup_panic = simple_strtoul(str, NULL, 0);
return 1;
}
__setup("softlockup_panic=", softlockup_panic_setup);
static int __init nowatchdog_setup(char *str) static int __init nowatchdog_setup(char *str)
{ {
watchdog_user_enabled = 0; watchdog_user_enabled = 0;