linux-kernel - [RFC PATCH 2/3] timer: del_timer_sync() can be used in softirq context

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1282633129-9187-3-git-send-email-yong.zhang0@gmail.com>
Date:	Tue, 24 Aug 2010 14:58:48 +0800
From:	Yong Zhang <yong.zhang0@...il.com>
To:	linux-kernel@...r.kernel.org
Cc:	tglx@...utronix.de, akpm@...ux-foundation.org, mingo@...e.hu,
	peterz@...radead.org, oleg@...hat.com
Subject: [RFC PATCH 2/3] timer: del_timer_sync() can be used in softirq context

From: Yong Zhang <yong.zhang@...driver.com>

Actually we have used del_timer_sync() in softirq context for a long
time, such as: __dst_free()::cancel_delayed_work() and maybe the
DEBUG_OBJECTS_TIMERS fundamental code.

So change the comments of it to warn on hardirq context only,
and make lockdep know about this change.

Signed-off-by: Yong Zhang <yong.zhang0@...il.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Ingo Molnar <mingo@...e.hu>
Cc: Peter Zijlstra <peterz@...radead.org>
---
 kernel/timer.c |    8 +++-----
 1 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/kernel/timer.c b/kernel/timer.c
index 55b6a2d..08c9559 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -981,7 +981,7 @@ EXPORT_SYMBOL(try_to_del_timer_sync);
  *
  * Synchronization rules: Callers must prevent restarting of the timer,
  * otherwise this function is meaningless. It must not be called from
- * interrupt contexts. The caller must not hold locks which would prevent
+ * hardirq contexts. The caller must not hold locks which would prevent
  * completion of the timer's handler. The timer's handler must not call
  * add_timer_on(). Upon exit the timer is not queued and the handler is
  * not running on any CPU.
@@ -991,12 +991,10 @@ EXPORT_SYMBOL(try_to_del_timer_sync);
 int del_timer_sync(struct timer_list *timer)
 {
 #ifdef CONFIG_LOCKDEP
-	unsigned long flags;
-
-	local_irq_save(flags);
+	local_bh_disable();
 	lock_map_acquire(&timer->lockdep_map);
 	lock_map_release(&timer->lockdep_map);
-	local_irq_restore(flags);
+	local_bh_enable();
 #endif
 
 	for (;;) {
-- 
1.7.0.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/