From: "Guilherme G. Piccoli" <gpiccoli@xxxxxxxxxxxxx>
Subject: 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@xxxxxxx
Link: http://lkml.kernel.org/r/20200507214624.21911-1-gpiccoli@xxxxxxxxxxxxx
Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Iurii Zaikin <yzaikin@xxxxxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/admin-guide/kernel-parameters.txt | 10 +--
fs/proc/proc_sysctl.c | 7 +-
kernel/watchdog.c | 37 +++-----------
3 files changed, 19 insertions(+), 35 deletions(-)
--- a/Documentation/admin-guide/kernel-parameters.txt~kernel-watchdogc-convert-soft-hardlockup-boot-parameters-to-sysctl-aliases
+++ a/Documentation/admin-guide/kernel-parameters.txt
@@ -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
--- a/fs/proc/proc_sysctl.c~kernel-watchdogc-convert-soft-hardlockup-boot-parameters-to-sysctl-aliases
+++ a/fs/proc/proc_sysctl.c
@@ -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" },
{ }
};
--- a/kernel/watchdog.c~kernel-watchdogc-convert-soft-hardlockup-boot-parameters-to-sysctl-aliases
+++ a/kernel/watchdog.c
@@ -50,6 +50,11 @@ struct cpumask watchdog_cpumask __read_m
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
}
__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_enabl
#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, hrt
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(
}
__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);
/*
_
