diff options
author | Steven Rostedt <rostedt@goodmis.org> | 2014-05-27 17:02:04 -0400 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2014-06-05 05:07:41 -0400 |
commit | e9dd685ce81815811fb4da72e6ab10a694ac8468 (patch) | |
tree | c429c73cf5883cf54aef8b07c71b212c1c708071 /kernel/sched/fair.c | |
parent | 6acbfb96976fc3350e30d964acb1dbbdf876d55e (diff) |
sched/numa: Fix use of spin_{un}lock_irq() when interrupts are disabled
As Peter Zijlstra told me, we have the following path:
do_exit()
exit_itimers()
itimer_delete()
spin_lock_irqsave(&timer->it_lock, &flags);
timer_delete_hook(timer);
kc->timer_del(timer) := posix_cpu_timer_del()
put_task_struct()
__put_task_struct()
task_numa_free()
spin_lock(&grp->lock);
Which means that task_numa_free() can be called with interrupts
disabled, which means that we should not be using spin_lock_irq() but
spin_lock_irqsave() instead. Otherwise we are enabling interrupts while
holding an interrupt unsafe lock!
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner<tglx@linutronix.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140527182541.GH11096@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/fair.c')
-rw-r--r-- | kernel/sched/fair.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 0fdb96de81a5..b4768c069392 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c | |||
@@ -1707,18 +1707,19 @@ no_join: | |||
1707 | void task_numa_free(struct task_struct *p) | 1707 | void task_numa_free(struct task_struct *p) |
1708 | { | 1708 | { |
1709 | struct numa_group *grp = p->numa_group; | 1709 | struct numa_group *grp = p->numa_group; |
1710 | int i; | ||
1711 | void *numa_faults = p->numa_faults_memory; | 1710 | void *numa_faults = p->numa_faults_memory; |
1711 | unsigned long flags; | ||
1712 | int i; | ||
1712 | 1713 | ||
1713 | if (grp) { | 1714 | if (grp) { |
1714 | spin_lock_irq(&grp->lock); | 1715 | spin_lock_irqsave(&grp->lock, flags); |
1715 | for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++) | 1716 | for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++) |
1716 | grp->faults[i] -= p->numa_faults_memory[i]; | 1717 | grp->faults[i] -= p->numa_faults_memory[i]; |
1717 | grp->total_faults -= p->total_numa_faults; | 1718 | grp->total_faults -= p->total_numa_faults; |
1718 | 1719 | ||
1719 | list_del(&p->numa_entry); | 1720 | list_del(&p->numa_entry); |
1720 | grp->nr_tasks--; | 1721 | grp->nr_tasks--; |
1721 | spin_unlock_irq(&grp->lock); | 1722 | spin_unlock_irqrestore(&grp->lock, flags); |
1722 | rcu_assign_pointer(p->numa_group, NULL); | 1723 | rcu_assign_pointer(p->numa_group, NULL); |
1723 | put_numa_group(grp); | 1724 | put_numa_group(grp); |
1724 | } | 1725 | } |