From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
"Liu, Chuansheng" <chuansheng.liu@intel.com>,
Steven Rostedt <rostedt@goodmis.org>,
"Ingo Molnar (mingo@kernel.org)" <mingo@kernel.org>,
"hpa@zytor.com" <hpa@zytor.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"x86@kernel.org" <x86@kernel.org>,
"'linux-kernel@vger.kernel.org' (linux-kernel@vger.kernel.org)"
<linux-kernel@vger.kernel.org>,
"Wang, Xiaoming" <xiaoming.wang@intel.com>,
"Li, Zhuangzhi" <zhuangzhi.li@intel.com>
Subject: Re: Panic and page fault in loop during handling NMI backtrace handler
Date: Tue, 15 Oct 2013 05:48:37 -0700 [thread overview]
Message-ID: <20131015124837.GC9150@linux.vnet.ibm.com> (raw)
In-Reply-To: <20131015123717.GJ10651@twins.programming.kicks-ass.net>
On Tue, Oct 15, 2013 at 02:37:17PM +0200, Peter Zijlstra wrote:
> On Tue, Oct 15, 2013 at 02:18:53PM +0200, Frederic Weisbecker wrote:
> > On Tue, Oct 15, 2013 at 02:01:04AM +0000, Liu, Chuansheng wrote:
> > > We meet one issue that during trigger all CPU backtrace, but during in the NMI handler arch_trigger_all_cpu_backtrace_handler,
> > > It hit the PAGE fault, then PAGE fault is in loop, at last the thread stack overflow, and system panic.
> > >
> > > Anyone can give some help? Thanks.
> >
> > Looks like we re-enter the fault several times. On x86-32, NMIs can
> > fault if they dereference vmalloc'ed area. I wonder if the module thing
> > we lookup in the NMI is stored on some vmalloc'ed area.
>
> IIRC modules are indeed allocated using vmalloc. See module_alloc()
> using vmalloc_exec()
This might then be a module that uses call_rcu(), but which does not have
the needed rcu_barrier() in the module-exit function.
Thanx, Paul
next prev parent reply other threads:[~2013-10-15 12:48 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <27240C0AC20F114CBF8149A2696CBE4A01B60835@SHSMSX101.ccr.corp.intel.com>
2013-10-15 12:18 ` Frederic Weisbecker
2013-10-15 12:37 ` Peter Zijlstra
2013-10-15 12:48 ` Paul E. McKenney [this message]
2013-10-15 12:59 ` Frederic Weisbecker
2013-10-15 13:06 ` Paul E. McKenney
2013-10-15 13:17 ` Frederic Weisbecker
2013-10-15 13:27 ` Paul E. McKenney
2013-10-15 12:54 ` Frederic Weisbecker
2013-10-15 14:19 ` Steven Rostedt
2013-10-15 16:40 ` Steven Rostedt
2013-10-16 1:54 ` Liu, Chuansheng
2013-10-16 2:07 ` Steven Rostedt
2013-10-16 2:09 ` Liu, Chuansheng
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=20131015124837.GC9150@linux.vnet.ibm.com \
--to=paulmck@linux.vnet.ibm.com \
--cc=akpm@linux-foundation.org \
--cc=chuansheng.liu@intel.com \
--cc=fweisbec@gmail.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=x86@kernel.org \
--cc=xiaoming.wang@intel.com \
--cc=zhuangzhi.li@intel.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®