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Date: Fri, 20 Mar 2009 13:03:34 +0530
From: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: [RFC][PATCH -tip 4/9] power: add kernel_trap_sp()
Message-ID: <20090320073334.GA10519@in.ibm.com>
References: <49C2B4BF.4080904@redhat.com> <1237527760.25062.567.camel@pasglop>
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Cc: LKML <linux-kernel@vger.kernel.org>, Steven Rostedt <rostedt@goodmis.org>,
	linuxppc-dev@ozlabs.org, systemtap-ml <systemtap@sources.redhat.com>,
	Ingo Molnar <mingo@elte.hu>, Masami Hiramatsu <mhiramat@redhat.com>
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On Fri, Mar 20, 2009 at 04:42:40PM +1100, Benjamin Herrenschmidt wrote:
> On Thu, 2009-03-19 at 17:10 -0400, Masami Hiramatsu wrote:
> > Add kernel_trap_sp() on powerpc, based on systemtap's runtime/regs.h.
> > 
> > Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
> 
> I haven't looked at the usage of it, but it's weird to have something
> call "kernel_trap_sp" that returns the -user- stack pointer... is
> this really what's expected here ?

In the current usage scenario, this gets called only with a pt_regs
snapshot from in kernel. user_stack_pointer() is a misnomer though;
all this macro needs is to return the stack pointer from the given
pt_regs.

Ananth