All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
To: heiko.carstens@de.ibm.com, rusty@rustcorp.com.au
Cc: lkml <linux-kernel@vger.kernel.org>
Subject: [PATCH] stop_cpu() needs to use raw_smp_processor_id()
Date: Tue, 16 Jun 2009 16:49:41 +0530	[thread overview]
Message-ID: <20090616111941.GA3287@in.ibm.com> (raw)

With DEBUG_PREEMPT on, on an s390 box, we are seeing:

BUG: using smp_processor_id() in preemptible [00000000] code: insmod/3006  
caller is arch_arm_kprobe+0x2c/0x90                                        
CPU: 0 Not tainted 2.6.30-rc8-tipjun10-02053-g39ae214 #7             
Process insmod (pid: 3006, task: 000000007df31410, ksp: 000000007e087a28)  
	0000000000000000 000000007e087c38 0000000000000002 0000000000000000
	000000007e087cd8 000000007e087c50 000000007e087c50 0000000000048156 
	00000000003e4de8 000000000002b830 0000000000000000 0000000000000000 
	0000000000000000 000000007e087c38 ffffffff0000000d 000000007e087ca8 
	000000000040a780 000000000001635c 000000007e087c38 000000007e087c80 
Call Trace:                                                                
([<00000000000162e6>] show_trace+0x13a/0x148)                              
 [<00000000001f123a>] debug_smp_processor_id+0x136/0x13c                   
 [<00000000003ddbd8>] arch_arm_kprobe+0x2c/0x90                            
 [<00000000003df8cc>] register_kprobe+0x630/0x684                          
 [<000003e000241056>] kprobe_init+0x56/0xa8 [kprobe_example]               
 [<00000000000120c2>] do_one_initcall+0x3e/0x16c                           
 [<000000000007cb4c>] SyS_init_module+0xc4/0x1fc                           
 [<0000000000027f42>] sysc_noemu+0x10/0x16                                 
 [<0000004a4493324e>] 0x4a4493324e           

Digging further this seems to be due to stop_cpu().

Shouldn't stop_cpu() be using raw_smp_processor_id()?

Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
---
 kernel/stop_machine.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6.30/kernel/stop_machine.c
===================================================================
--- linux-2.6.30.orig/kernel/stop_machine.c
+++ linux-2.6.30/kernel/stop_machine.c
@@ -68,7 +68,7 @@ static void stop_cpu(struct work_struct 
 {
 	enum stopmachine_state curstate = STOPMACHINE_NONE;
 	struct stop_machine_data *smdata = &idle;
-	int cpu = smp_processor_id();
+	int cpu = raw_smp_processor_id();
 	int err;
 
 	if (!active_cpus) {

             reply	other threads:[~2009-06-16 11:19 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-16 11:19 Ananth N Mavinakayanahalli [this message]
2009-06-16 11:51 ` [PATCH] stop_cpu() needs to use raw_smp_processor_id() Heiko Carstens
2009-06-17  7:01   ` Maran
2009-06-22  9:11     ` Heiko Carstens
2009-06-22 14:34       ` Maran

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=20090616111941.GA3287@in.ibm.com \
    --to=ananth@in.ibm.com \
    --cc=heiko.carstens@de.ibm.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rusty@rustcorp.com.au \
    /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.