time: Remove CONFIG_TIMER_STATS
Currently CONFIG_TIMER_STATS exposes process information across namespaces:
kernel/time/timer_list.c print_timer():
SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
/proc/timer_list:
#11: <0000000000000000>, hrtimer_wakeup, S:01, do_nanosleep, cron/2570
Given that the tracer can give the same information, this patch entirely
removes CONFIG_TIMER_STATS.
Change-Id: I66e06ae2d6e32c309824310d3d9bf54d1047eab1
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: linux-doc@vger.kernel.org
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Xing Gao <xgao01@email.wm.edu>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jessica Frazelle <me@jessfraz.com>
Cc: kernel-hardening@lists.openwall.com
Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Michal Marek <mmarek@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-api@vger.kernel.org
Cc: Arjan van de Ven <arjan@linux.intel.com>
Link: http://lkml.kernel.org/r/20170208192659.GA32582@beast
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Git-commit: dfb4357da6ddbdf57d583ba64361c9d792b0e0b1
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[ohaugan@codeaurora.org: Fixed merge conflicts]
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 5463c3b..adede73 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -575,38 +575,6 @@
trigger_dyntick_cpu(base, timer);
}
-#ifdef CONFIG_TIMER_STATS
-void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr)
-{
- if (timer->start_site)
- return;
-
- timer->start_site = addr;
- memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
- timer->start_pid = current->pid;
-}
-
-static void timer_stats_account_timer(struct timer_list *timer)
-{
- void *site;
-
- /*
- * start_site can be concurrently reset by
- * timer_stats_timer_clear_start_info()
- */
- site = READ_ONCE(timer->start_site);
- if (likely(!site))
- return;
-
- timer_stats_update_stats(timer, timer->start_pid, site,
- timer->function, timer->start_comm,
- timer->flags);
-}
-
-#else
-static void timer_stats_account_timer(struct timer_list *timer) {}
-#endif
-
#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
static struct debug_obj_descr timer_debug_descr;
@@ -793,11 +761,6 @@
{
timer->entry.pprev = NULL;
timer->flags = flags | raw_smp_processor_id();
-#ifdef CONFIG_TIMER_STATS
- timer->start_site = NULL;
- timer->start_pid = -1;
- memset(timer->start_comm, 0, TASK_COMM_LEN);
-#endif
lockdep_init_map(&timer->lockdep_map, name, key, 0);
}
@@ -1011,8 +974,6 @@
base = lock_timer_base(timer, &flags);
}
- timer_stats_timer_set_start_info(timer);
-
ret = detach_if_pending(timer, base, false);
if (!ret && pending_only)
goto out_unlock;
@@ -1140,7 +1101,6 @@
struct timer_base *new_base, *base;
unsigned long flags;
- timer_stats_timer_set_start_info(timer);
BUG_ON(timer_pending(timer) || !timer->function);
new_base = get_timer_cpu_base(timer->flags, cpu);
@@ -1186,7 +1146,6 @@
debug_assert_init(timer);
- timer_stats_timer_clear_start_info(timer);
if (timer_pending(timer)) {
base = lock_timer_base(timer, &flags);
ret = detach_if_pending(timer, base, true);
@@ -1214,10 +1173,9 @@
base = lock_timer_base(timer, &flags);
- if (base->running_timer != timer) {
- timer_stats_timer_clear_start_info(timer);
+ if (base->running_timer != timer)
ret = detach_if_pending(timer, base, true);
- }
+
spin_unlock_irqrestore(&base->lock, flags);
return ret;
@@ -1341,7 +1299,6 @@
unsigned long data;
timer = hlist_entry(head->first, struct timer_list, entry);
- timer_stats_account_timer(timer);
base->running_timer = timer;
detach_timer(timer, true);
@@ -1916,7 +1873,6 @@
void __init init_timers(void)
{
init_timer_cpus();
- init_timer_stats();
open_softirq(TIMER_SOFTIRQ, run_timer_softirq);
}