From mboxrd@z Thu Jan  1 00:00:00 1970
From: James Hogan <james.hogan@imgtec.com>
Subject: Re: pt_regs leak into userspace (was Re: [PATCH v3 20/71] ARC: Signal
 handling)
Date: Mon, 11 Feb 2013 11:01:47 +0000
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References: <1359024639-21915-1-git-send-email-vgupta@synopsys.com> <1359024639-21915-9-git-send-email-vgupta@synopsys.com> <51189D2F.4030000@synopsys.com> <CACM3HyGNZxfOXpw01POBVT-YcVKQsnPkO6Kgg+epfZS-x-BRCg@mail.gmail.com> <5118C458.2070205@synopsys.com> <5118C7B6.6040807@imgtec.com> <CACM3HyG+4Pzx02iL9atxG+FOLiCcTeXR+ivzRO78bqDHNp5rGQ@mail.gmail.com>
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To: Jonas Bonn <jonas.bonn@gmail.com>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>, 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>

Hi Jonas,

On 11/02/13 10:53, Jonas Bonn wrote:
> And now that I think about it some more, I think this is done
> incorrectly in the openrisc arch, too, as the fast-path for
> rt_sigreturn probably only restores the call-clobbered regs.
> sigreturn probably needs to be special-cased to _always_ restore all
> the regs on its way back to userspace.  Not for the "signal" case, but
> for the "setcontext" case; but these two are pretty-much
> indistinguishable.

Wouldn't setcontext restore a different stack, so the sigreturn wouldn't
happen until the ucontext is switched back?

Cheers
James