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Date: Wed, 20 Mar 2013 21:12:45 +0530
From: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
To: Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCH] powerpc/uprobes: teach uprobes to ignore gdb breakpoints
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References: <20130320104033.GA19844@in.ibm.com>
 <20130320122639.GA29541@redhat.com> <20130320124301.GA30887@redhat.com>
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Cc: ppcdev <linuxppc-dev@lists.ozlabs.org>,
 Srikar Dronamraju <srikar@linux.vnet.ibm.com>, stable@vger.kernel.org
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On Wed, Mar 20, 2013 at 01:43:01PM +0100, Oleg Nesterov wrote:
> On 03/20, Oleg Nesterov wrote:
> >
> > But we did not install UPROBE_SWBP_INSN. Is it fine? I hope yes, just to
> > verify. If not, we need 2 definitions. is_uprobe_insn() should still check
> > insns == UPROBE_SWBP_INSN, and is_swbp_insn() should check is_trap().
> >
> > And I am just curious, could you explain how X and UPROBE_SWBP_INSN
> > differ?
> 
> IOW, if I wasn't clear... Lets forget about gdb/etc for the moment.
> Suppose we apply the patch below. Will uprobes on powerpc work?
> 
> If yes, then your patch should be fine. If not, we probably need more
> changes.

Yes, it will work fine.

> And, forgot to mention. If you change is_swbp_insn(), you can remove
> is_trap() from arch_uprobe_analyze_insn().

Yeah, that check is no longer needed. I'll send a separate cleanup after
this patch gets applied.

Ananth