From: Peter Zijlstra <peterz@infradead.org>
To: mingo@kernel.org, oleg@redhat.com, torvalds@linux-foundation.org
Cc: tglx@linutronix.de, ilya.dryomov@inktank.com,
umgwanakikbuti@gmail.com, linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Rusty Russell <rusty@rustcorp.com.au>,
Fengguang Wu <fengguang.wu@intel.com>
Subject: [PATCH 08/11] module: Fix nested sleep
Date: Wed, 24 Sep 2014 10:18:53 +0200 [thread overview]
Message-ID: <20140924082242.458562904@infradead.org> (raw)
In-Reply-To: 20140924081845.572814794@infradead.org
[-- Attachment #1: peterz-sleep-module.patch --]
[-- Type: text/plain, Size: 1661 bytes --]
A genuine bug, we cannot use blocking primitives inside a wait loop.
So rewrite the wait_event_interruptible() usage to use the fresh
wait_woken() stuff.
Cc: Rusty Russell <rusty@rustcorp.com.au>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
kernel/module.c | 30 ++++++++++++++++++++++++++++--
1 file changed, 28 insertions(+), 2 deletions(-)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3095,6 +3095,32 @@ static int may_init_module(void)
}
/*
+ * Can't use wait_event_interruptible() because our condition
+ * 'finished_loading()' contains a blocking primitive itself (mutex_lock).
+ */
+static int wait_finished_loading(struct module *mod)
+{
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
+ int ret = 0;
+
+ add_wait_queue(&module_wq, &wait);
+ for (;;) {
+ if (finished_loading(mod->name))
+ break;
+
+ if (signal_pending_state(TASK_INTERRUPTIBLE, current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
+ }
+ remove_wait_queue(&module_wq, &wait);
+
+ return ret;
+}
+
+/*
* We try to place it in the list now to make sure it's unique before
* we dedicate too many resources. In particular, temporary percpu
* memory exhaustion.
@@ -3114,8 +3140,8 @@ static int add_unformed_module(struct mo
|| old->state == MODULE_STATE_UNFORMED) {
/* Wait in case it fails to load. */
mutex_unlock(&module_mutex);
- err = wait_event_interruptible(module_wq,
- finished_loading(mod->name));
+
+ err = wait_finished_loading(mod);
if (err)
goto out_unlocked;
goto again;
next prev parent reply other threads:[~2014-09-24 8:36 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-24 8:18 [PATCH 00/11] nested sleeps, fixes and debug infrastructure Peter Zijlstra
2014-09-24 8:18 ` [PATCH 01/11] locking/mutex: Dont assume TASK_RUNNING Peter Zijlstra
2014-10-28 11:09 ` [tip:sched/core] locking/mutex: Don't " tip-bot for Peter Zijlstra
2014-09-24 8:18 ` [PATCH 02/11] wait: Provide infrastructure to deal with nested blocking Peter Zijlstra
2014-09-29 21:02 ` Oleg Nesterov
2014-10-02 7:37 ` Peter Zijlstra
2014-10-02 21:21 ` Oleg Nesterov
2014-10-28 11:09 ` [tip:sched/core] sched/wait: " tip-bot for Peter Zijlstra
2014-09-24 8:18 ` [PATCH 03/11] wait: Add might_sleep() Peter Zijlstra
2014-10-28 11:09 ` [tip:sched/core] sched/wait: Add might_sleep() checks tip-bot for Peter Zijlstra
2014-09-24 8:18 ` [PATCH 04/11] exit: Deal with nested sleeps Peter Zijlstra
2014-10-28 11:10 ` [tip:sched/core] sched, " tip-bot for Peter Zijlstra
2014-09-24 8:18 ` [PATCH 05/11] inotify: " Peter Zijlstra
2014-10-28 11:10 ` [tip:sched/core] sched, " tip-bot for Peter Zijlstra
2014-09-24 8:18 ` [PATCH 06/11] tty: " Peter Zijlstra
2014-10-28 11:10 ` [tip:sched/core] sched, " tip-bot for Peter Zijlstra
2014-09-24 8:18 ` [PATCH 07/11] smp: Correctly deal " Peter Zijlstra
2014-10-28 11:11 ` [tip:sched/core] sched, " tip-bot for Peter Zijlstra
2014-09-24 8:18 ` Peter Zijlstra [this message]
2014-09-29 22:18 ` [PATCH 08/11] module: Fix nested sleep Oleg Nesterov
2014-09-30 13:43 ` Peter Zijlstra
2014-10-28 11:11 ` [tip:sched/core] sched, modules: Fix nested sleep in add_unformed_module() tip-bot for Peter Zijlstra
2014-09-24 8:18 ` [PATCH 09/11] net: Clean up sk_wait_event() vs might_sleep() Peter Zijlstra
2014-09-24 8:36 ` Peter Zijlstra
2014-10-28 11:11 ` [tip:sched/core] sched, net: Clean up sk_wait_event() vs. might_sleep() tip-bot for Peter Zijlstra
2014-09-24 8:18 ` [PATCH 10/11] sched: Debug nested sleeps Peter Zijlstra
2014-09-29 22:13 ` Oleg Nesterov
2014-09-30 13:49 ` Peter Zijlstra
2014-09-30 21:47 ` Oleg Nesterov
2014-10-01 16:10 ` Peter Zijlstra
2014-10-01 18:35 ` Oleg Nesterov
2014-10-02 9:07 ` Peter Zijlstra
2014-10-02 21:34 ` Oleg Nesterov
2014-10-28 11:11 ` [tip:sched/core] " tip-bot for Peter Zijlstra
2014-09-24 8:18 ` [PATCH 11/11] sched: Exclude cond_resched() from nested sleep test Peter Zijlstra
2014-10-28 11:12 ` [tip:sched/core] " tip-bot for Peter Zijlstra
2014-09-25 8:30 ` [PATCH 00/11] nested sleeps, fixes and debug infrastructure Mike Galbraith
2014-09-25 9:06 ` Peter Zijlstra
2014-09-25 9:10 ` Mike Galbraith
2014-09-25 9:15 ` Peter Zijlstra
2014-09-25 9:56 ` Mike Galbraith
2014-09-25 13:59 ` BUG: sleeping function called from invalid context at drivers/cpufreq/cpufreq.c:370 Mike Galbraith
2014-09-26 6:24 ` Mike Galbraith
2014-09-26 7:54 ` Mike Galbraith
2014-09-26 14:10 ` Rafael J. Wysocki
2014-09-26 22:44 ` Rafael J. Wysocki
2014-09-27 6:14 ` Mike Galbraith
2014-09-27 19:57 ` Rafael J. Wysocki
2014-10-02 10:22 ` [PATCH 00/11] nested sleeps, fixes and debug infrastructure Peter Zijlstra
2014-10-02 12:15 ` Peter Zijlstra
2014-10-27 13:41 ` Peter Zijlstra
2014-10-28 0:07 ` Oleg Nesterov
2014-10-28 8:23 ` Peter Zijlstra
2014-10-29 0:00 ` Oleg Nesterov
2014-10-29 9:35 ` Peter Zijlstra
2014-10-29 11:31 ` Peter Zijlstra
2014-10-29 11:36 ` Peter Zijlstra
2014-10-29 14:26 ` Peter Zijlstra
2014-11-04 16:08 ` [tip:sched/core] audit, sched/wait: Fixup kauditd_thread() wait loop tip-bot for Peter Zijlstra
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