From mboxrd@z Thu Jan  1 00:00:00 1970
From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Subject: Re: pt_regs leak into userspace (was Re: [PATCH v3 20/71] ARC: Signal
 handling)
Date: Mon, 11 Feb 2013 15:43:44 +0530
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To: Jonas Bonn <jonas.bonn@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>, "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Al Viro <viro@zeniv.linux.org.uk>

On Monday 11 February 2013 03:06 PM, Jonas Bonn wrote:
> On 11 February 2013 08:26, Vineet Gupta <Vineet.Gupta1@synopsys.com> wrote:
>
>> The only downside of this patch is that userspace signal stack grows in size,
>> since signal frame only cares about scratch regs (pt_regs), but has to accommodate
>> unused placeholder for callee regs too by virtue of using user_regs_struct.
> Is this really true?  Don't setcontext and friends require that _all_
> the registers be part of sigcontext?

But for an ABI - callee saved regs will anyhow be saved/restored even in
setcontext case ! So collecting it for that purpose seems useless, or am I missing
something here.

-Vineet