Commit f117955a authored by Guilherme G. Piccoli's avatar Guilherme G. Piccoli Committed by Linus Torvalds

kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases

After a recent change introduced by Vlastimil's series [0], kernel is
able now to handle sysctl parameters on kernel command line; also, the
series introduced a simple infrastructure to convert legacy boot
parameters (that duplicate sysctls) into sysctl aliases.

This patch converts the watchdog parameters softlockup_panic and
{hard,soft}lockup_all_cpu_backtrace to use the new alias infrastructure.
It fixes the documentation too, since the alias only accepts values 0 or
1, not the full range of integers.

We also took the opportunity here to improve the documentation of the
previously converted hung_task_panic (see the patch series [0]) and put
the alias table in alphabetical order.

[0] http://lkml.kernel.org/r/20200427180433.7029-1-vbabka@suse.czSigned-off-by: default avatarGuilherme G. Piccoli <gpiccoli@canonical.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Link: http://lkml.kernel.org/r/20200507214624.21911-1-gpiccoli@canonical.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4f2f682d
......@@ -1445,7 +1445,7 @@
hardlockup_all_cpu_backtrace=
[KNL] Should the hard-lockup detector generate
backtraces on all cpus.
Format: <integer>
Format: 0 | 1
hashdist= [KNL,NUMA] Large hashes allocated during boot
are distributed across NUMA nodes. Defaults on
......@@ -1513,7 +1513,7 @@
hung_task_panic=
[KNL] Should the hung task detector generate panics.
Format: <integer>
Format: 0 | 1
A value of 1 instructs the kernel to panic when a
hung task is detected. The default value is controlled
......@@ -4665,9 +4665,9 @@
softlockup_panic=
[KNL] Should the soft-lockup detector generate panics.
Format: <integer>
Format: 0 | 1
A nonzero value instructs the soft-lockup detector
A value of 1 instructs the soft-lockup detector
to panic the machine when a soft-lockup occurs. It is
also controlled by the kernel.softlockup_panic sysctl
and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the
......@@ -4676,7 +4676,7 @@
softlockup_all_cpu_backtrace=
[KNL] Should the soft-lockup detector generate
backtraces on all cpus.
Format: <integer>
Format: 0 | 1
sonypi.*= [HW] Sony Programmable I/O Control Device driver
See Documentation/admin-guide/laptops/sonypi.rst
......
......@@ -1720,8 +1720,11 @@ struct sysctl_alias {
* parameter.
*/
static const struct sysctl_alias sysctl_aliases[] = {
{"numa_zonelist_order", "vm.numa_zonelist_order" },
{"hung_task_panic", "kernel.hung_task_panic" },
{"hardlockup_all_cpu_backtrace", "kernel.hardlockup_all_cpu_backtrace" },
{"hung_task_panic", "kernel.hung_task_panic" },
{"numa_zonelist_order", "vm.numa_zonelist_order" },
{"softlockup_all_cpu_backtrace", "kernel.softlockup_all_cpu_backtrace" },
{"softlockup_panic", "kernel.softlockup_panic" },
{ }
};
......
......@@ -50,6 +50,11 @@ struct cpumask watchdog_cpumask __read_mostly;
unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);
#ifdef CONFIG_HARDLOCKUP_DETECTOR
# ifdef CONFIG_SMP
int __read_mostly sysctl_hardlockup_all_cpu_backtrace;
# endif /* CONFIG_SMP */
/*
* Should we panic when a soft-lockup or hard-lockup occurs:
*/
......@@ -82,16 +87,6 @@ static int __init hardlockup_panic_setup(char *str)
}
__setup("nmi_watchdog=", hardlockup_panic_setup);
# ifdef CONFIG_SMP
int __read_mostly sysctl_hardlockup_all_cpu_backtrace;
static int __init hardlockup_all_cpu_backtrace_setup(char *str)
{
sysctl_hardlockup_all_cpu_backtrace = !!simple_strtol(str, NULL, 0);
return 1;
}
__setup("hardlockup_all_cpu_backtrace=", hardlockup_all_cpu_backtrace_setup);
# endif /* CONFIG_SMP */
#endif /* CONFIG_HARDLOCKUP_DETECTOR */
/*
......@@ -163,6 +158,10 @@ static void lockup_detector_update_enable(void)
#define SOFTLOCKUP_RESET ULONG_MAX
#ifdef CONFIG_SMP
int __read_mostly sysctl_softlockup_all_cpu_backtrace;
#endif
/* Global variables, exported for sysctl */
unsigned int __read_mostly softlockup_panic =
CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;
......@@ -178,13 +177,6 @@ static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts);
static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
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)
{
watchdog_user_enabled = 0;
......@@ -206,17 +198,6 @@ static int __init watchdog_thresh_setup(char *str)
}
__setup("watchdog_thresh=", watchdog_thresh_setup);
#ifdef CONFIG_SMP
int __read_mostly sysctl_softlockup_all_cpu_backtrace;
static int __init softlockup_all_cpu_backtrace_setup(char *str)
{
sysctl_softlockup_all_cpu_backtrace = !!simple_strtol(str, NULL, 0);
return 1;
}
__setup("softlockup_all_cpu_backtrace=", softlockup_all_cpu_backtrace_setup);
#endif
static void __lockup_detector_cleanup(void);
/*
......
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