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Date: Thu, 23 Sep 2010 00:12:19 +0100
From: Al Viro <viro@ZenIV.linux.org.uk>
To: David Miller <davem@davemloft.net>
Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org,
        sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [GIT] Sparc
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On Wed, Sep 22, 2010 at 02:15:14PM -0700, David Miller wrote:

> Alternatively, #2 could be implemented using a special ptrace getregs
> call created specifically to fetch the windowed registers.  And
> the regset implementation of that could be used for dumping them
> into core files as well, and this specifically I've been meaning to
> do at some point.
> 
> Again, let me think about this some more.

OK... sparc32 question: just what the !@#!@# happens if sun4c_rett_stackchk
find (%fp & 7) != 0?  We go to ret_trap_user_stack_is_bolixed, which
tries to page in the underlying page.  OK, suppose it's already there and
readable; we return without doing anything - and go to signal_p.  Which finds
itself with nothing to do, and %fp is *still* buggered.  Spin ad infinitum?
srmmu_rett_stackchk will do the same, BTW...