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Date: Thu, 21 Apr 2011 22:40:42 +0530
From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Subject: Re: [PATCH v3 2.6.39-rc1-tip 15/26] 15: uprobes: Handing int3 and
 singlestep exception.
Message-ID: <20110421171042.GI10698@linux.vnet.ibm.com>
Reply-To: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
References: <20110401143223.15455.19844.sendpatchset@localhost6.localdomain6>
 <20110401143527.15455.32854.sendpatchset@localhost6.localdomain6>
 <1303218185.8345.0.camel@twins>
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Sender: owner-linux-mm@kvack.org
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To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>, Steven Rostedt <rostedt@goodmis.org>, Linux-mm <linux-mm@kvack.org>, Arnaldo Carvalho de Melo <acme@infradead.org>, Linus Torvalds <torvalds@linux-foundation.org>, Jonathan Corbet <corbet@lwn.net>, Christoph Hellwig <hch@infradead.org>, Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>, Thomas Gleixner <tglx@linutronix.de>, Ananth N Mavinakayanahalli <ananth@in.ibm.com>, Oleg Nesterov <oleg@redhat.com>, LKML <linux-kernel@vger.kernel.org>, SystemTap <systemtap@sources.redhat.com>, Jim Keniston <jkenisto@linux.vnet.ibm.com>, Roland McGrath <roland@hack.frob.com>, Andi Kleen <andi@firstfloor.org>, Andrew Morton <akpm@linux-foundation.org>

* Peter Zijlstra <peterz@infradead.org> [2011-04-19 15:03:05]:

> On Fri, 2011-04-01 at 20:05 +0530, Srikar Dronamraju wrote:
> > +       if (unlikely(!utask)) {
> > +               utask = add_utask();
> > +
> > +               /* Failed to allocate utask for the current task. */
> > +               BUG_ON(!utask);
> 
> That's not really nice is it ;-) means I can make the kernel go BUG by
> simply applying memory pressure.
> 

The other option would be remove the probe and set the ip to
the breakpoint address and restart the thread.


-- 
Thanks and Regards
Srikar

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