mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 02:39:48 +00:00
![Nathan Zimmer](/assets/img/avatar_default.png)
Correct an issue with /proc/timer_list reported by Holger. When reading from the proc file with a sufficiently small buffer, 2k so not really that small, there was one could get hung trying to read the file a chunk at a time. The timer_list_start function failed to account for the possibility that the offset was adjusted outside the timer_list_next. Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> Reported-by: Holger Hans Peter Freyther <holger@freyther.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Berke Durak <berke.durak@xiphos.com> Cc: Jeff Layton <jlayton@redhat.com> Tested-by: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> # 3.10.x Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
370 lines
9 KiB
C
370 lines
9 KiB
C
/*
|
|
* kernel/time/timer_list.c
|
|
*
|
|
* List pending timers
|
|
*
|
|
* Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/module.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/seq_file.h>
|
|
#include <linux/kallsyms.h>
|
|
#include <linux/tick.h>
|
|
|
|
#include <asm/uaccess.h>
|
|
|
|
|
|
struct timer_list_iter {
|
|
int cpu;
|
|
bool second_pass;
|
|
u64 now;
|
|
};
|
|
|
|
typedef void (*print_fn_t)(struct seq_file *m, unsigned int *classes);
|
|
|
|
DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
|
|
|
|
/*
|
|
* This allows printing both to /proc/timer_list and
|
|
* to the console (on SysRq-Q):
|
|
*/
|
|
#define SEQ_printf(m, x...) \
|
|
do { \
|
|
if (m) \
|
|
seq_printf(m, x); \
|
|
else \
|
|
printk(x); \
|
|
} while (0)
|
|
|
|
static void print_name_offset(struct seq_file *m, void *sym)
|
|
{
|
|
char symname[KSYM_NAME_LEN];
|
|
|
|
if (lookup_symbol_name((unsigned long)sym, symname) < 0)
|
|
SEQ_printf(m, "<%pK>", sym);
|
|
else
|
|
SEQ_printf(m, "%s", symname);
|
|
}
|
|
|
|
static void
|
|
print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
|
|
int idx, u64 now)
|
|
{
|
|
#ifdef CONFIG_TIMER_STATS
|
|
char tmp[TASK_COMM_LEN + 1];
|
|
#endif
|
|
SEQ_printf(m, " #%d: ", idx);
|
|
print_name_offset(m, taddr);
|
|
SEQ_printf(m, ", ");
|
|
print_name_offset(m, timer->function);
|
|
SEQ_printf(m, ", S:%02lx", timer->state);
|
|
#ifdef CONFIG_TIMER_STATS
|
|
SEQ_printf(m, ", ");
|
|
print_name_offset(m, timer->start_site);
|
|
memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
|
|
tmp[TASK_COMM_LEN] = 0;
|
|
SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
|
|
#endif
|
|
SEQ_printf(m, "\n");
|
|
SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
|
|
(unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
|
|
(unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
|
|
(long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
|
|
(long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
|
|
}
|
|
|
|
static void
|
|
print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
|
|
u64 now)
|
|
{
|
|
struct hrtimer *timer, tmp;
|
|
unsigned long next = 0, i;
|
|
struct timerqueue_node *curr;
|
|
unsigned long flags;
|
|
|
|
next_one:
|
|
i = 0;
|
|
raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
|
|
|
|
curr = timerqueue_getnext(&base->active);
|
|
/*
|
|
* Crude but we have to do this O(N*N) thing, because
|
|
* we have to unlock the base when printing:
|
|
*/
|
|
while (curr && i < next) {
|
|
curr = timerqueue_iterate_next(curr);
|
|
i++;
|
|
}
|
|
|
|
if (curr) {
|
|
|
|
timer = container_of(curr, struct hrtimer, node);
|
|
tmp = *timer;
|
|
raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
|
|
|
|
print_timer(m, timer, &tmp, i, now);
|
|
next++;
|
|
goto next_one;
|
|
}
|
|
raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
|
|
}
|
|
|
|
static void
|
|
print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
|
|
{
|
|
SEQ_printf(m, " .base: %pK\n", base);
|
|
SEQ_printf(m, " .index: %d\n",
|
|
base->index);
|
|
SEQ_printf(m, " .resolution: %Lu nsecs\n",
|
|
(unsigned long long)ktime_to_ns(base->resolution));
|
|
SEQ_printf(m, " .get_time: ");
|
|
print_name_offset(m, base->get_time);
|
|
SEQ_printf(m, "\n");
|
|
#ifdef CONFIG_HIGH_RES_TIMERS
|
|
SEQ_printf(m, " .offset: %Lu nsecs\n",
|
|
(unsigned long long) ktime_to_ns(base->offset));
|
|
#endif
|
|
SEQ_printf(m, "active timers:\n");
|
|
print_active_timers(m, base, now);
|
|
}
|
|
|
|
static void print_cpu(struct seq_file *m, int cpu, u64 now)
|
|
{
|
|
struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
|
|
int i;
|
|
|
|
SEQ_printf(m, "cpu: %d\n", cpu);
|
|
for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
|
|
SEQ_printf(m, " clock %d:\n", i);
|
|
print_base(m, cpu_base->clock_base + i, now);
|
|
}
|
|
#define P(x) \
|
|
SEQ_printf(m, " .%-15s: %Lu\n", #x, \
|
|
(unsigned long long)(cpu_base->x))
|
|
#define P_ns(x) \
|
|
SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \
|
|
(unsigned long long)(ktime_to_ns(cpu_base->x)))
|
|
|
|
#ifdef CONFIG_HIGH_RES_TIMERS
|
|
P_ns(expires_next);
|
|
P(hres_active);
|
|
P(nr_events);
|
|
P(nr_retries);
|
|
P(nr_hangs);
|
|
P_ns(max_hang_time);
|
|
#endif
|
|
#undef P
|
|
#undef P_ns
|
|
|
|
#ifdef CONFIG_TICK_ONESHOT
|
|
# define P(x) \
|
|
SEQ_printf(m, " .%-15s: %Lu\n", #x, \
|
|
(unsigned long long)(ts->x))
|
|
# define P_ns(x) \
|
|
SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \
|
|
(unsigned long long)(ktime_to_ns(ts->x)))
|
|
{
|
|
struct tick_sched *ts = tick_get_tick_sched(cpu);
|
|
P(nohz_mode);
|
|
P_ns(last_tick);
|
|
P(tick_stopped);
|
|
P(idle_jiffies);
|
|
P(idle_calls);
|
|
P(idle_sleeps);
|
|
P_ns(idle_entrytime);
|
|
P_ns(idle_waketime);
|
|
P_ns(idle_exittime);
|
|
P_ns(idle_sleeptime);
|
|
P_ns(iowait_sleeptime);
|
|
P(last_jiffies);
|
|
P(next_jiffies);
|
|
P_ns(idle_expires);
|
|
SEQ_printf(m, "jiffies: %Lu\n",
|
|
(unsigned long long)jiffies);
|
|
}
|
|
#endif
|
|
|
|
#undef P
|
|
#undef P_ns
|
|
SEQ_printf(m, "\n");
|
|
}
|
|
|
|
#ifdef CONFIG_GENERIC_CLOCKEVENTS
|
|
static void
|
|
print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
|
|
{
|
|
struct clock_event_device *dev = td->evtdev;
|
|
|
|
SEQ_printf(m, "Tick Device: mode: %d\n", td->mode);
|
|
if (cpu < 0)
|
|
SEQ_printf(m, "Broadcast device\n");
|
|
else
|
|
SEQ_printf(m, "Per CPU device: %d\n", cpu);
|
|
|
|
SEQ_printf(m, "Clock Event Device: ");
|
|
if (!dev) {
|
|
SEQ_printf(m, "<NULL>\n");
|
|
return;
|
|
}
|
|
SEQ_printf(m, "%s\n", dev->name);
|
|
SEQ_printf(m, " max_delta_ns: %llu\n",
|
|
(unsigned long long) dev->max_delta_ns);
|
|
SEQ_printf(m, " min_delta_ns: %llu\n",
|
|
(unsigned long long) dev->min_delta_ns);
|
|
SEQ_printf(m, " mult: %u\n", dev->mult);
|
|
SEQ_printf(m, " shift: %u\n", dev->shift);
|
|
SEQ_printf(m, " mode: %d\n", dev->mode);
|
|
SEQ_printf(m, " next_event: %Ld nsecs\n",
|
|
(unsigned long long) ktime_to_ns(dev->next_event));
|
|
|
|
SEQ_printf(m, " set_next_event: ");
|
|
print_name_offset(m, dev->set_next_event);
|
|
SEQ_printf(m, "\n");
|
|
|
|
SEQ_printf(m, " set_mode: ");
|
|
print_name_offset(m, dev->set_mode);
|
|
SEQ_printf(m, "\n");
|
|
|
|
SEQ_printf(m, " event_handler: ");
|
|
print_name_offset(m, dev->event_handler);
|
|
SEQ_printf(m, "\n");
|
|
SEQ_printf(m, " retries: %lu\n", dev->retries);
|
|
SEQ_printf(m, "\n");
|
|
}
|
|
|
|
static void timer_list_show_tickdevices_header(struct seq_file *m)
|
|
{
|
|
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
|
|
print_tickdevice(m, tick_get_broadcast_device(), -1);
|
|
SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
|
|
cpumask_bits(tick_get_broadcast_mask())[0]);
|
|
#ifdef CONFIG_TICK_ONESHOT
|
|
SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
|
|
cpumask_bits(tick_get_broadcast_oneshot_mask())[0]);
|
|
#endif
|
|
SEQ_printf(m, "\n");
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
static inline void timer_list_header(struct seq_file *m, u64 now)
|
|
{
|
|
SEQ_printf(m, "Timer List Version: v0.7\n");
|
|
SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
|
|
SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
|
|
SEQ_printf(m, "\n");
|
|
}
|
|
|
|
static int timer_list_show(struct seq_file *m, void *v)
|
|
{
|
|
struct timer_list_iter *iter = v;
|
|
|
|
if (iter->cpu == -1 && !iter->second_pass)
|
|
timer_list_header(m, iter->now);
|
|
else if (!iter->second_pass)
|
|
print_cpu(m, iter->cpu, iter->now);
|
|
#ifdef CONFIG_GENERIC_CLOCKEVENTS
|
|
else if (iter->cpu == -1 && iter->second_pass)
|
|
timer_list_show_tickdevices_header(m);
|
|
else
|
|
print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
void sysrq_timer_list_show(void)
|
|
{
|
|
u64 now = ktime_to_ns(ktime_get());
|
|
int cpu;
|
|
|
|
timer_list_header(NULL, now);
|
|
|
|
for_each_online_cpu(cpu)
|
|
print_cpu(NULL, cpu, now);
|
|
|
|
#ifdef CONFIG_GENERIC_CLOCKEVENTS
|
|
timer_list_show_tickdevices_header(NULL);
|
|
for_each_online_cpu(cpu)
|
|
print_tickdevice(NULL, tick_get_device(cpu), cpu);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
static void *move_iter(struct timer_list_iter *iter, loff_t offset)
|
|
{
|
|
for (; offset; offset--) {
|
|
iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
|
|
if (iter->cpu >= nr_cpu_ids) {
|
|
#ifdef CONFIG_GENERIC_CLOCKEVENTS
|
|
if (!iter->second_pass) {
|
|
iter->cpu = -1;
|
|
iter->second_pass = true;
|
|
} else
|
|
return NULL;
|
|
#else
|
|
return NULL;
|
|
#endif
|
|
}
|
|
}
|
|
return iter;
|
|
}
|
|
|
|
static void *timer_list_start(struct seq_file *file, loff_t *offset)
|
|
{
|
|
struct timer_list_iter *iter = file->private;
|
|
|
|
if (!*offset)
|
|
iter->now = ktime_to_ns(ktime_get());
|
|
iter->cpu = -1;
|
|
iter->second_pass = false;
|
|
return move_iter(iter, *offset);
|
|
}
|
|
|
|
static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset)
|
|
{
|
|
struct timer_list_iter *iter = file->private;
|
|
++*offset;
|
|
return move_iter(iter, 1);
|
|
}
|
|
|
|
static void timer_list_stop(struct seq_file *seq, void *v)
|
|
{
|
|
}
|
|
|
|
static const struct seq_operations timer_list_sops = {
|
|
.start = timer_list_start,
|
|
.next = timer_list_next,
|
|
.stop = timer_list_stop,
|
|
.show = timer_list_show,
|
|
};
|
|
|
|
static int timer_list_open(struct inode *inode, struct file *filp)
|
|
{
|
|
return seq_open_private(filp, &timer_list_sops,
|
|
sizeof(struct timer_list_iter));
|
|
}
|
|
|
|
static const struct file_operations timer_list_fops = {
|
|
.open = timer_list_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release_private,
|
|
};
|
|
|
|
static int __init init_timer_list_procfs(void)
|
|
{
|
|
struct proc_dir_entry *pe;
|
|
|
|
pe = proc_create("timer_list", 0444, NULL, &timer_list_fops);
|
|
if (!pe)
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
__initcall(init_timer_list_procfs);
|