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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Detect hard and soft lockups on a system
- *
- * started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
- *
- * Note: Most of this code is borrowed heavily from the original softlockup
- * detector, so thanks to Ingo for the initial implementation.
- * Some chunks also taken from the old x86-specific nmi watchdog code, thanks
- * to those contributors as well.
- */
- #define pr_fmt(fmt) "watchdog: " fmt
- #include <linux/mm.h>
- #include <linux/cpu.h>
- #include <linux/nmi.h>
- #include <linux/init.h>
- #include <linux/module.h>
- #include <linux/sysctl.h>
- #include <linux/tick.h>
- #include <linux/sched/clock.h>
- #include <linux/sched/debug.h>
- #include <linux/sched/isolation.h>
- #include <linux/stop_machine.h>
- #include <asm/irq_regs.h>
- #include <linux/kvm_para.h>
- #include <trace/hooks/softlockup.h>
- static DEFINE_MUTEX(watchdog_mutex);
- #if defined(CONFIG_HARDLOCKUP_DETECTOR) || defined(CONFIG_HAVE_NMI_WATCHDOG)
- # define WATCHDOG_DEFAULT (SOFT_WATCHDOG_ENABLED | NMI_WATCHDOG_ENABLED)
- # define NMI_WATCHDOG_DEFAULT 1
- #else
- # define WATCHDOG_DEFAULT (SOFT_WATCHDOG_ENABLED)
- # define NMI_WATCHDOG_DEFAULT 0
- #endif
- unsigned long __read_mostly watchdog_enabled;
- int __read_mostly watchdog_user_enabled = 1;
- int __read_mostly nmi_watchdog_user_enabled = NMI_WATCHDOG_DEFAULT;
- int __read_mostly soft_watchdog_user_enabled = 1;
- int __read_mostly watchdog_thresh = 10;
- static int __read_mostly nmi_watchdog_available;
- 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:
- */
- unsigned int __read_mostly hardlockup_panic =
- IS_ENABLED(CONFIG_BOOTPARAM_HARDLOCKUP_PANIC);
- /*
- * We may not want to enable hard lockup detection by default in all cases,
- * for example when running the kernel as a guest on a hypervisor. In these
- * cases this function can be called to disable hard lockup detection. This
- * function should only be executed once by the boot processor before the
- * kernel command line parameters are parsed, because otherwise it is not
- * possible to override this in hardlockup_panic_setup().
- */
- void __init hardlockup_detector_disable(void)
- {
- nmi_watchdog_user_enabled = 0;
- }
- static int __init hardlockup_panic_setup(char *str)
- {
- if (!strncmp(str, "panic", 5))
- hardlockup_panic = 1;
- else if (!strncmp(str, "nopanic", 7))
- hardlockup_panic = 0;
- else if (!strncmp(str, "0", 1))
- nmi_watchdog_user_enabled = 0;
- else if (!strncmp(str, "1", 1))
- nmi_watchdog_user_enabled = 1;
- return 1;
- }
- __setup("nmi_watchdog=", hardlockup_panic_setup);
- #endif /* CONFIG_HARDLOCKUP_DETECTOR */
- /*
- * These functions can be overridden if an architecture implements its
- * own hardlockup detector.
- *
- * watchdog_nmi_enable/disable can be implemented to start and stop when
- * softlockup watchdog start and stop. The arch must select the
- * SOFTLOCKUP_DETECTOR Kconfig.
- */
- int __weak watchdog_nmi_enable(unsigned int cpu)
- {
- hardlockup_detector_perf_enable();
- return 0;
- }
- void __weak watchdog_nmi_disable(unsigned int cpu)
- {
- hardlockup_detector_perf_disable();
- }
- /* Return 0, if a NMI watchdog is available. Error code otherwise */
- int __weak __init watchdog_nmi_probe(void)
- {
- return hardlockup_detector_perf_init();
- }
- /**
- * watchdog_nmi_stop - Stop the watchdog for reconfiguration
- *
- * The reconfiguration steps are:
- * watchdog_nmi_stop();
- * update_variables();
- * watchdog_nmi_start();
- */
- void __weak watchdog_nmi_stop(void) { }
- /**
- * watchdog_nmi_start - Start the watchdog after reconfiguration
- *
- * Counterpart to watchdog_nmi_stop().
- *
- * The following variables have been updated in update_variables() and
- * contain the currently valid configuration:
- * - watchdog_enabled
- * - watchdog_thresh
- * - watchdog_cpumask
- */
- void __weak watchdog_nmi_start(void) { }
- /**
- * lockup_detector_update_enable - Update the sysctl enable bit
- *
- * Caller needs to make sure that the NMI/perf watchdogs are off, so this
- * can't race with watchdog_nmi_disable().
- */
- static void lockup_detector_update_enable(void)
- {
- watchdog_enabled = 0;
- if (!watchdog_user_enabled)
- return;
- if (nmi_watchdog_available && nmi_watchdog_user_enabled)
- watchdog_enabled |= NMI_WATCHDOG_ENABLED;
- if (soft_watchdog_user_enabled)
- watchdog_enabled |= SOFT_WATCHDOG_ENABLED;
- }
- #ifdef CONFIG_SOFTLOCKUP_DETECTOR
- /*
- * Delay the soflockup report when running a known slow code.
- * It does _not_ affect the timestamp of the last successdul reschedule.
- */
- #define SOFTLOCKUP_DELAY_REPORT ULONG_MAX
- #ifdef CONFIG_SMP
- int __read_mostly sysctl_softlockup_all_cpu_backtrace;
- #endif
- static struct cpumask watchdog_allowed_mask __read_mostly;
- /* Global variables, exported for sysctl */
- unsigned int __read_mostly softlockup_panic =
- IS_ENABLED(CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC);
- static bool softlockup_initialized __read_mostly;
- static u64 __read_mostly sample_period;
- /* Timestamp taken after the last successful reschedule. */
- static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts);
- /* Timestamp of the last softlockup report. */
- static DEFINE_PER_CPU(unsigned long, watchdog_report_ts);
- static DEFINE_PER_CPU(struct hrtimer, watchdog_hrtimer);
- static DEFINE_PER_CPU(bool, softlockup_touch_sync);
- 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;
- return 1;
- }
- __setup("nowatchdog", nowatchdog_setup);
- static int __init nosoftlockup_setup(char *str)
- {
- soft_watchdog_user_enabled = 0;
- return 1;
- }
- __setup("nosoftlockup", nosoftlockup_setup);
- static int __init watchdog_thresh_setup(char *str)
- {
- get_option(&str, &watchdog_thresh);
- return 1;
- }
- __setup("watchdog_thresh=", watchdog_thresh_setup);
- static void __lockup_detector_cleanup(void);
- /*
- * Hard-lockup warnings should be triggered after just a few seconds. Soft-
- * lockups can have false positives under extreme conditions. So we generally
- * want a higher threshold for soft lockups than for hard lockups. So we couple
- * the thresholds with a factor: we make the soft threshold twice the amount of
- * time the hard threshold is.
- */
- static int get_softlockup_thresh(void)
- {
- return watchdog_thresh * 2;
- }
- /*
- * Returns seconds, approximately. We don't need nanosecond
- * resolution, and we don't need to waste time with a big divide when
- * 2^30ns == 1.074s.
- */
- static unsigned long get_timestamp(void)
- {
- return running_clock() >> 30LL; /* 2^30 ~= 10^9 */
- }
- static void set_sample_period(void)
- {
- /*
- * convert watchdog_thresh from seconds to ns
- * the divide by 5 is to give hrtimer several chances (two
- * or three with the current relation between the soft
- * and hard thresholds) to increment before the
- * hardlockup detector generates a warning
- */
- sample_period = get_softlockup_thresh() * ((u64)NSEC_PER_SEC / 5);
- watchdog_update_hrtimer_threshold(sample_period);
- }
- static void update_report_ts(void)
- {
- __this_cpu_write(watchdog_report_ts, get_timestamp());
- }
- /* Commands for resetting the watchdog */
- static void update_touch_ts(void)
- {
- __this_cpu_write(watchdog_touch_ts, get_timestamp());
- update_report_ts();
- }
- /**
- * touch_softlockup_watchdog_sched - touch watchdog on scheduler stalls
- *
- * Call when the scheduler may have stalled for legitimate reasons
- * preventing the watchdog task from executing - e.g. the scheduler
- * entering idle state. This should only be used for scheduler events.
- * Use touch_softlockup_watchdog() for everything else.
- */
- notrace void touch_softlockup_watchdog_sched(void)
- {
- /*
- * Preemption can be enabled. It doesn't matter which CPU's watchdog
- * report period gets restarted here, so use the raw_ operation.
- */
- raw_cpu_write(watchdog_report_ts, SOFTLOCKUP_DELAY_REPORT);
- }
- notrace void touch_softlockup_watchdog(void)
- {
- touch_softlockup_watchdog_sched();
- wq_watchdog_touch(raw_smp_processor_id());
- }
- EXPORT_SYMBOL(touch_softlockup_watchdog);
- void touch_all_softlockup_watchdogs(void)
- {
- int cpu;
- /*
- * watchdog_mutex cannpt be taken here, as this might be called
- * from (soft)interrupt context, so the access to
- * watchdog_allowed_cpumask might race with a concurrent update.
- *
- * The watchdog time stamp can race against a concurrent real
- * update as well, the only side effect might be a cycle delay for
- * the softlockup check.
- */
- for_each_cpu(cpu, &watchdog_allowed_mask) {
- per_cpu(watchdog_report_ts, cpu) = SOFTLOCKUP_DELAY_REPORT;
- wq_watchdog_touch(cpu);
- }
- }
- void touch_softlockup_watchdog_sync(void)
- {
- __this_cpu_write(softlockup_touch_sync, true);
- __this_cpu_write(watchdog_report_ts, SOFTLOCKUP_DELAY_REPORT);
- }
- static int is_softlockup(unsigned long touch_ts,
- unsigned long period_ts,
- unsigned long now)
- {
- if ((watchdog_enabled & SOFT_WATCHDOG_ENABLED) && watchdog_thresh){
- /* Warn about unreasonable delays. */
- if (time_after(now, period_ts + get_softlockup_thresh()))
- return now - touch_ts;
- }
- return 0;
- }
- /* watchdog detector functions */
- bool is_hardlockup(void)
- {
- unsigned long hrint = __this_cpu_read(hrtimer_interrupts);
- if (__this_cpu_read(hrtimer_interrupts_saved) == hrint)
- return true;
- __this_cpu_write(hrtimer_interrupts_saved, hrint);
- return false;
- }
- static void watchdog_interrupt_count(void)
- {
- __this_cpu_inc(hrtimer_interrupts);
- }
- static DEFINE_PER_CPU(struct completion, softlockup_completion);
- static DEFINE_PER_CPU(struct cpu_stop_work, softlockup_stop_work);
- /*
- * The watchdog feed function - touches the timestamp.
- *
- * It only runs once every sample_period seconds (4 seconds by
- * default) to reset the softlockup timestamp. If this gets delayed
- * for more than 2*watchdog_thresh seconds then the debug-printout
- * triggers in watchdog_timer_fn().
- */
- static int softlockup_fn(void *data)
- {
- update_touch_ts();
- complete(this_cpu_ptr(&softlockup_completion));
- return 0;
- }
- /* watchdog kicker functions */
- static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
- {
- unsigned long touch_ts, period_ts, now;
- struct pt_regs *regs = get_irq_regs();
- int duration;
- int softlockup_all_cpu_backtrace = sysctl_softlockup_all_cpu_backtrace;
- if (!watchdog_enabled)
- return HRTIMER_NORESTART;
- /* kick the hardlockup detector */
- watchdog_interrupt_count();
- /* kick the softlockup detector */
- if (completion_done(this_cpu_ptr(&softlockup_completion))) {
- reinit_completion(this_cpu_ptr(&softlockup_completion));
- stop_one_cpu_nowait(smp_processor_id(),
- softlockup_fn, NULL,
- this_cpu_ptr(&softlockup_stop_work));
- }
- /* .. and repeat */
- hrtimer_forward_now(hrtimer, ns_to_ktime(sample_period));
- /*
- * Read the current timestamp first. It might become invalid anytime
- * when a virtual machine is stopped by the host or when the watchog
- * is touched from NMI.
- */
- now = get_timestamp();
- /*
- * If a virtual machine is stopped by the host it can look to
- * the watchdog like a soft lockup. This function touches the watchdog.
- */
- kvm_check_and_clear_guest_paused();
- /*
- * The stored timestamp is comparable with @now only when not touched.
- * It might get touched anytime from NMI. Make sure that is_softlockup()
- * uses the same (valid) value.
- */
- period_ts = READ_ONCE(*this_cpu_ptr(&watchdog_report_ts));
- /* Reset the interval when touched by known problematic code. */
- if (period_ts == SOFTLOCKUP_DELAY_REPORT) {
- if (unlikely(__this_cpu_read(softlockup_touch_sync))) {
- /*
- * If the time stamp was touched atomically
- * make sure the scheduler tick is up to date.
- */
- __this_cpu_write(softlockup_touch_sync, false);
- sched_clock_tick();
- }
- update_report_ts();
- return HRTIMER_RESTART;
- }
- /* Check for a softlockup. */
- touch_ts = __this_cpu_read(watchdog_touch_ts);
- duration = is_softlockup(touch_ts, period_ts, now);
- if (unlikely(duration)) {
- /*
- * Prevent multiple soft-lockup reports if one cpu is already
- * engaged in dumping all cpu back traces.
- */
- if (softlockup_all_cpu_backtrace) {
- if (test_and_set_bit_lock(0, &soft_lockup_nmi_warn))
- return HRTIMER_RESTART;
- }
- /* Start period for the next softlockup warning. */
- update_report_ts();
- pr_emerg("BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n",
- smp_processor_id(), duration,
- current->comm, task_pid_nr(current));
- print_modules();
- print_irqtrace_events(current);
- if (regs)
- show_regs(regs);
- else
- dump_stack();
- if (softlockup_all_cpu_backtrace) {
- trigger_allbutself_cpu_backtrace();
- clear_bit_unlock(0, &soft_lockup_nmi_warn);
- }
- trace_android_vh_watchdog_timer_softlockup(duration, regs, !!softlockup_panic);
- add_taint(TAINT_SOFTLOCKUP, LOCKDEP_STILL_OK);
- if (softlockup_panic)
- panic("softlockup: hung tasks");
- }
- return HRTIMER_RESTART;
- }
- static void watchdog_enable(unsigned int cpu)
- {
- struct hrtimer *hrtimer = this_cpu_ptr(&watchdog_hrtimer);
- struct completion *done = this_cpu_ptr(&softlockup_completion);
- WARN_ON_ONCE(cpu != smp_processor_id());
- init_completion(done);
- complete(done);
- /*
- * Start the timer first to prevent the NMI watchdog triggering
- * before the timer has a chance to fire.
- */
- hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
- hrtimer->function = watchdog_timer_fn;
- hrtimer_start(hrtimer, ns_to_ktime(sample_period),
- HRTIMER_MODE_REL_PINNED_HARD);
- /* Initialize timestamp */
- update_touch_ts();
- /* Enable the perf event */
- if (watchdog_enabled & NMI_WATCHDOG_ENABLED)
- watchdog_nmi_enable(cpu);
- }
- static void watchdog_disable(unsigned int cpu)
- {
- struct hrtimer *hrtimer = this_cpu_ptr(&watchdog_hrtimer);
- WARN_ON_ONCE(cpu != smp_processor_id());
- /*
- * Disable the perf event first. That prevents that a large delay
- * between disabling the timer and disabling the perf event causes
- * the perf NMI to detect a false positive.
- */
- watchdog_nmi_disable(cpu);
- hrtimer_cancel(hrtimer);
- wait_for_completion(this_cpu_ptr(&softlockup_completion));
- }
- static int softlockup_stop_fn(void *data)
- {
- watchdog_disable(smp_processor_id());
- return 0;
- }
- static void softlockup_stop_all(void)
- {
- int cpu;
- if (!softlockup_initialized)
- return;
- for_each_cpu(cpu, &watchdog_allowed_mask)
- smp_call_on_cpu(cpu, softlockup_stop_fn, NULL, false);
- cpumask_clear(&watchdog_allowed_mask);
- }
- static int softlockup_start_fn(void *data)
- {
- watchdog_enable(smp_processor_id());
- return 0;
- }
- static void softlockup_start_all(void)
- {
- int cpu;
- cpumask_copy(&watchdog_allowed_mask, &watchdog_cpumask);
- for_each_cpu(cpu, &watchdog_allowed_mask)
- smp_call_on_cpu(cpu, softlockup_start_fn, NULL, false);
- }
- int lockup_detector_online_cpu(unsigned int cpu)
- {
- if (cpumask_test_cpu(cpu, &watchdog_allowed_mask))
- watchdog_enable(cpu);
- return 0;
- }
- int lockup_detector_offline_cpu(unsigned int cpu)
- {
- if (cpumask_test_cpu(cpu, &watchdog_allowed_mask))
- watchdog_disable(cpu);
- return 0;
- }
- static void __lockup_detector_reconfigure(void)
- {
- cpus_read_lock();
- watchdog_nmi_stop();
- softlockup_stop_all();
- set_sample_period();
- lockup_detector_update_enable();
- if (watchdog_enabled && watchdog_thresh)
- softlockup_start_all();
- watchdog_nmi_start();
- cpus_read_unlock();
- /*
- * Must be called outside the cpus locked section to prevent
- * recursive locking in the perf code.
- */
- __lockup_detector_cleanup();
- }
- void lockup_detector_reconfigure(void)
- {
- mutex_lock(&watchdog_mutex);
- __lockup_detector_reconfigure();
- mutex_unlock(&watchdog_mutex);
- }
- /*
- * Create the watchdog infrastructure and configure the detector(s).
- */
- static __init void lockup_detector_setup(void)
- {
- /*
- * If sysctl is off and watchdog got disabled on the command line,
- * nothing to do here.
- */
- lockup_detector_update_enable();
- if (!IS_ENABLED(CONFIG_SYSCTL) &&
- !(watchdog_enabled && watchdog_thresh))
- return;
- mutex_lock(&watchdog_mutex);
- __lockup_detector_reconfigure();
- softlockup_initialized = true;
- mutex_unlock(&watchdog_mutex);
- }
- #else /* CONFIG_SOFTLOCKUP_DETECTOR */
- static void __lockup_detector_reconfigure(void)
- {
- cpus_read_lock();
- watchdog_nmi_stop();
- lockup_detector_update_enable();
- watchdog_nmi_start();
- cpus_read_unlock();
- }
- void lockup_detector_reconfigure(void)
- {
- __lockup_detector_reconfigure();
- }
- static inline void lockup_detector_setup(void)
- {
- __lockup_detector_reconfigure();
- }
- #endif /* !CONFIG_SOFTLOCKUP_DETECTOR */
- static void __lockup_detector_cleanup(void)
- {
- lockdep_assert_held(&watchdog_mutex);
- hardlockup_detector_perf_cleanup();
- }
- /**
- * lockup_detector_cleanup - Cleanup after cpu hotplug or sysctl changes
- *
- * Caller must not hold the cpu hotplug rwsem.
- */
- void lockup_detector_cleanup(void)
- {
- mutex_lock(&watchdog_mutex);
- __lockup_detector_cleanup();
- mutex_unlock(&watchdog_mutex);
- }
- /**
- * lockup_detector_soft_poweroff - Interface to stop lockup detector(s)
- *
- * Special interface for parisc. It prevents lockup detector warnings from
- * the default pm_poweroff() function which busy loops forever.
- */
- void lockup_detector_soft_poweroff(void)
- {
- watchdog_enabled = 0;
- }
- #ifdef CONFIG_SYSCTL
- /* Propagate any changes to the watchdog infrastructure */
- static void proc_watchdog_update(void)
- {
- /* Remove impossible cpus to keep sysctl output clean. */
- cpumask_and(&watchdog_cpumask, &watchdog_cpumask, cpu_possible_mask);
- __lockup_detector_reconfigure();
- }
- /*
- * common function for watchdog, nmi_watchdog and soft_watchdog parameter
- *
- * caller | table->data points to | 'which'
- * -------------------|----------------------------|--------------------------
- * proc_watchdog | watchdog_user_enabled | NMI_WATCHDOG_ENABLED |
- * | | SOFT_WATCHDOG_ENABLED
- * -------------------|----------------------------|--------------------------
- * proc_nmi_watchdog | nmi_watchdog_user_enabled | NMI_WATCHDOG_ENABLED
- * -------------------|----------------------------|--------------------------
- * proc_soft_watchdog | soft_watchdog_user_enabled | SOFT_WATCHDOG_ENABLED
- */
- static int proc_watchdog_common(int which, struct ctl_table *table, int write,
- void *buffer, size_t *lenp, loff_t *ppos)
- {
- int err, old, *param = table->data;
- mutex_lock(&watchdog_mutex);
- if (!write) {
- /*
- * On read synchronize the userspace interface. This is a
- * racy snapshot.
- */
- *param = (watchdog_enabled & which) != 0;
- err = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
- } else {
- old = READ_ONCE(*param);
- err = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
- if (!err && old != READ_ONCE(*param))
- proc_watchdog_update();
- }
- mutex_unlock(&watchdog_mutex);
- return err;
- }
- /*
- * /proc/sys/kernel/watchdog
- */
- int proc_watchdog(struct ctl_table *table, int write,
- void *buffer, size_t *lenp, loff_t *ppos)
- {
- return proc_watchdog_common(NMI_WATCHDOG_ENABLED|SOFT_WATCHDOG_ENABLED,
- table, write, buffer, lenp, ppos);
- }
- /*
- * /proc/sys/kernel/nmi_watchdog
- */
- int proc_nmi_watchdog(struct ctl_table *table, int write,
- void *buffer, size_t *lenp, loff_t *ppos)
- {
- if (!nmi_watchdog_available && write)
- return -ENOTSUPP;
- return proc_watchdog_common(NMI_WATCHDOG_ENABLED,
- table, write, buffer, lenp, ppos);
- }
- /*
- * /proc/sys/kernel/soft_watchdog
- */
- int proc_soft_watchdog(struct ctl_table *table, int write,
- void *buffer, size_t *lenp, loff_t *ppos)
- {
- return proc_watchdog_common(SOFT_WATCHDOG_ENABLED,
- table, write, buffer, lenp, ppos);
- }
- /*
- * /proc/sys/kernel/watchdog_thresh
- */
- int proc_watchdog_thresh(struct ctl_table *table, int write,
- void *buffer, size_t *lenp, loff_t *ppos)
- {
- int err, old;
- mutex_lock(&watchdog_mutex);
- old = READ_ONCE(watchdog_thresh);
- err = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
- if (!err && write && old != READ_ONCE(watchdog_thresh))
- proc_watchdog_update();
- mutex_unlock(&watchdog_mutex);
- return err;
- }
- /*
- * The cpumask is the mask of possible cpus that the watchdog can run
- * on, not the mask of cpus it is actually running on. This allows the
- * user to specify a mask that will include cpus that have not yet
- * been brought online, if desired.
- */
- int proc_watchdog_cpumask(struct ctl_table *table, int write,
- void *buffer, size_t *lenp, loff_t *ppos)
- {
- int err;
- mutex_lock(&watchdog_mutex);
- err = proc_do_large_bitmap(table, write, buffer, lenp, ppos);
- if (!err && write)
- proc_watchdog_update();
- mutex_unlock(&watchdog_mutex);
- return err;
- }
- static const int sixty = 60;
- static struct ctl_table watchdog_sysctls[] = {
- {
- .procname = "watchdog",
- .data = &watchdog_user_enabled,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_watchdog,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
- },
- {
- .procname = "watchdog_thresh",
- .data = &watchdog_thresh,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_watchdog_thresh,
- .extra1 = SYSCTL_ZERO,
- .extra2 = (void *)&sixty,
- },
- {
- .procname = "nmi_watchdog",
- .data = &nmi_watchdog_user_enabled,
- .maxlen = sizeof(int),
- .mode = NMI_WATCHDOG_SYSCTL_PERM,
- .proc_handler = proc_nmi_watchdog,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
- },
- {
- .procname = "watchdog_cpumask",
- .data = &watchdog_cpumask_bits,
- .maxlen = NR_CPUS,
- .mode = 0644,
- .proc_handler = proc_watchdog_cpumask,
- },
- #ifdef CONFIG_SOFTLOCKUP_DETECTOR
- {
- .procname = "soft_watchdog",
- .data = &soft_watchdog_user_enabled,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_soft_watchdog,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
- },
- {
- .procname = "softlockup_panic",
- .data = &softlockup_panic,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
- },
- #ifdef CONFIG_SMP
- {
- .procname = "softlockup_all_cpu_backtrace",
- .data = &sysctl_softlockup_all_cpu_backtrace,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
- },
- #endif /* CONFIG_SMP */
- #endif
- #ifdef CONFIG_HARDLOCKUP_DETECTOR
- {
- .procname = "hardlockup_panic",
- .data = &hardlockup_panic,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
- },
- #ifdef CONFIG_SMP
- {
- .procname = "hardlockup_all_cpu_backtrace",
- .data = &sysctl_hardlockup_all_cpu_backtrace,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
- },
- #endif /* CONFIG_SMP */
- #endif
- {}
- };
- static void __init watchdog_sysctl_init(void)
- {
- register_sysctl_init("kernel", watchdog_sysctls);
- }
- #else
- #define watchdog_sysctl_init() do { } while (0)
- #endif /* CONFIG_SYSCTL */
- void __init lockup_detector_init(void)
- {
- if (tick_nohz_full_enabled())
- pr_info("Disabling watchdog on nohz_full cores by default\n");
- cpumask_copy(&watchdog_cpumask,
- housekeeping_cpumask(HK_TYPE_TIMER));
- if (!watchdog_nmi_probe())
- nmi_watchdog_available = true;
- lockup_detector_setup();
- watchdog_sysctl_init();
- }
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