From mboxrd@z Thu Jan  1 00:00:00 1970
From: Al Viro <viro@ZenIV.linux.org.uk>
Subject: Re: [RFC] TIF_NOTIFY_RESUME, arch/*/*/*signal*.c and all such
Date: Wed, 2 May 2012 18:24:53 +0100
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On Tue, May 01, 2012 at 06:52:26AM +0100, Al Viro wrote:
> IOW, here's what I'd suggest doing:
> 
> * add that regs->orig_p0 = -1; to handle_restart()
> * add jump .Lresume_userspace_1 after the call of do_notify_resume()
> * instead of RESTORE_CONTEXT/rti in ret_from_fork and kernel_execve()
> have them jump to .Lresume_userspace.

arrrgh...  The last one is unfortunately not so simple - you have that
in the guts of _system_call, which is called via pseudo_long_call,
so it would ought to be a call into the middle of _system_call, followed
by that RESTORE_CONTEXT/rti...