Re: pt_regs leak into userspace (was Re: [PATCH v3 20/71] ARC: Signalhandling)

From: Vineet Gupta
Date: Mon Feb 11 2013 - 05:15:16 EST


On Monday 11 February 2013 03:06 PM, Jonas Bonn wrote:
> On 11 February 2013 08:26, Vineet Gupta <Vineet.Gupta1@xxxxxxxxxxxx> 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

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