All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: akpm@linux-foundation.org, mingo@elte.hu,
	linux-kernel@vger.kernel.org, laijs@cn.fujitsu.com,
	dipankar@in.ibm.com, josh@joshtriplett.org, dvhltc@us.ibm.com,
	niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org,
	rostedt@goodmis.org, Valdis.Kletnieks@vt.edu,
	dhowells@redhat.com, eric.dumazet@gmail.com, adobriyan@gmail.com,
	davem@davemloft.net
Subject: [PATCH] rcu fix rcu head init on stack in rcutree_plugin.h
Date: Wed, 21 Apr 2010 21:23:09 -0400	[thread overview]
Message-ID: <20100422012309.GB32400@Krystal> (raw)
In-Reply-To: <20100421173145.GA6966@linux.vnet.ibm.com>

[Paul]
[...]
And testing got me the following debugobjects splat
[...]
ODEBUG: object is on stack, but not annotated
------------[ cut here ]------------
Badness at lib/debugobjects.c:294
NIP: c0000000002c76f0 LR: c0000000002c76ec CTR: c00000000041ecd8
REGS: c0000001de71b280 TRAP: 0700   Tainted: G        W   (2.6.34-rc3-autokern1)
MSR: 8000000000029032 <EE,ME,CE,IR,DR>  CR: 24000424  XER: 0000000f
TASK = c0000001de7dca00[3695] 'arping' THREAD: c0000001de718000 CPU: 1
GPR00: c0000000002c76ec c0000001de71b500 c00000000096c048 0000000000000034 
GPR04: 0000000000000001 c000000000063918 0000000000000000 0000000000000002 
GPR08: 0000000000000003 0000000000000000 c000000000086f68 c0000001de7dca00 
GPR12: 000000000000256d c0000000074e4200 0000000000000000 0000000000000000 
GPR16: 0000000000000000 0000000000000000 0000000000000000 00000000201b8f60 
GPR20: 00000000201b8f70 00000000201b8f48 0000000000000000 c0000000008766b8 
GPR24: c0000001de71b800 0000000000000001 c0000000008ad400 c000000001247478 
GPR28: c0000000e6abb8c0 c0000000e6abb8c0 c000000000904570 c000000001247470 
NIP [c0000000002c76f0] .__debug_object_init+0x314/0x40c
LR [c0000000002c76ec] .__debug_object_init+0x310/0x40c
Call Trace:
[c0000001de71b500] [c0000000002c76ec] .__debug_object_init+0x310/0x40c (unreliable)
[c0000001de71b5d0] [c00000000007d990] .rcuhead_fixup_activate+0x40/0xdc
[c0000001de71b660] [c0000000002c6a7c] .debug_object_fixup+0x4c/0x74
[c0000001de71b6f0] [c0000000000c5e54] .__call_rcu+0x3c/0x1d4
[c0000001de71b790] [c0000000000c6050] .synchronize_rcu+0x4c/0x6c
[c0000001de71b870] [c0000000004be218] .synchronize_net+0x10/0x24
[c0000001de71b8e0] [c0000000005498c8] .packet_release+0x1d4/0x274
[c0000001de71b990] [c0000000004ac1f0] .sock_release+0x54/0x124
[c0000001de71ba20] [c0000000004ac9e4] .sock_close+0x34/0x4c
[c0000001de71baa0] [c00000000012469c] .__fput+0x174/0x264
[c0000001de71bb40] [c000000000120c54] .filp_close+0xb0/0xd8
[c0000001de71bbd0] [c000000000065e70] .put_files_struct+0x1a8/0x314
[c0000001de71bc70] [c000000000067e04] .do_exit+0x234/0x6f0
[c0000001de71bd30] [c000000000068354] .do_group_exit+0x94/0xc8
[c0000001de71bdc0] [c00000000006839c] .SyS_exit_group+0x14/0x28
[c0000001de71be30] [c000000000008554] syscall_exit+0x0/0x40
Instruction dump:
7f80b000 419e0030 2fa00000 e93e8140 380b0001 90090000 419e000c e87e8148 
48000008 e87e8150 4bd9cb89 60000000 <0fe00000> 801c0010 2f800003 419e0024 

[Mathieu]

Here is the fix.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
---
 kernel/rcutree_plugin.h |    2 ++
 1 file changed, 2 insertions(+)

Index: linux.trees.git/kernel/rcutree_plugin.h
===================================================================
--- linux.trees.git.orig/kernel/rcutree_plugin.h	2010-04-21 21:15:45.000000000 -0400
+++ linux.trees.git/kernel/rcutree_plugin.h	2010-04-21 21:16:57.000000000 -0400
@@ -515,11 +515,13 @@ void synchronize_rcu(void)
 	if (!rcu_scheduler_active)
 		return;
 
+	init_rcu_head_on_stack(&rcu.head);
 	init_completion(&rcu.completion);
 	/* Will wake me after RCU finished. */
 	call_rcu(&rcu.head, wakeme_after_rcu);
 	/* Wait for it. */
 	wait_for_completion(&rcu.completion);
+	destroy_rcu_head_on_stack(&rcu.head);
 }
 EXPORT_SYMBOL_GPL(synchronize_rcu);
 
-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com

  parent reply	other threads:[~2010-04-22  1:23 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-17 12:48 [patch 0/5] rcu head debugobjects Mathieu Desnoyers
2010-04-17 12:48 ` [patch 1/5] Debugobjects transition check Mathieu Desnoyers
2010-04-17 12:48 ` [patch 2/5] rcu head introduce rcu head init on stack Mathieu Desnoyers
2010-04-17 12:48 ` [patch 3/5] remove all rcu head initializations, except on_stack initializations Mathieu Desnoyers
2010-04-17 12:48 ` [patch 4/5] rcu head remove init Mathieu Desnoyers
2010-04-17 12:48 ` [patch 5/5] tree/tiny rcu: Add debug RCU head objects (v5) Mathieu Desnoyers
2010-04-19  1:17   ` Lai Jiangshan
2010-04-19 13:34     ` Paul E. McKenney
2010-04-18  0:48 ` [patch 0/5] rcu head debugobjects Paul E. McKenney
2010-04-21 17:31   ` Paul E. McKenney
2010-04-22  1:20     ` Mathieu Desnoyers
2010-04-22  1:23     ` Mathieu Desnoyers [this message]
2010-04-22 22:52       ` [PATCH] rcu fix rcu head init on stack in rcutree_plugin.h Paul E. McKenney

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20100422012309.GB32400@Krystal \
    --to=mathieu.desnoyers@efficios.com \
    --cc=Valdis.Kletnieks@vt.edu \
    --cc=adobriyan@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=davem@davemloft.net \
    --cc=dhowells@redhat.com \
    --cc=dipankar@in.ibm.com \
    --cc=dvhltc@us.ibm.com \
    --cc=eric.dumazet@gmail.com \
    --cc=josh@joshtriplett.org \
    --cc=laijs@cn.fujitsu.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=niv@us.ibm.com \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.