From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 05 Feb 2007 01:10:57 +0000 (GMT) Received: from localhost.localdomain ([127.0.0.1]:61373 "EHLO dl5rb.ham-radio-op.net") by ftp.linux-mips.org with ESMTP id S20039067AbXBEBKz (ORCPT ); Mon, 5 Feb 2007 01:10:55 +0000 Received: from denk.linux-mips.net (denk.linux-mips.net [127.0.0.1]) by dl5rb.ham-radio-op.net (8.13.8/8.13.8) with ESMTP id l151AouQ026750; Mon, 5 Feb 2007 01:10:50 GMT Received: (from ralf@localhost) by denk.linux-mips.net (8.13.8/8.13.8/Submit) id l151AmFV026749; Mon, 5 Feb 2007 01:10:48 GMT Date: Mon, 5 Feb 2007 01:10:48 +0000 From: Ralf Baechle To: Daniel Jacobowitz Cc: David Daney , Franck Bui-Huu , linux-mips Subject: Re: Question about signal syscalls ! Message-ID: <20070205011048.GA26654@linux-mips.org> References: <20070201135734.GB12728@linux-mips.org> <45C21CFE.9060804@avtrex.com> <45C3611D.7000702@avtrex.com> <45C36D46.5040409@avtrex.com> <45C3A1E3.8010802@avtrex.com> <20070205005516.GA1581@nevyn.them.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070205005516.GA1581@nevyn.them.org> User-Agent: Mutt/1.4.2.2i Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 13919 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Sun, Feb 04, 2007 at 07:55:16PM -0500, Daniel Jacobowitz wrote: > On Fri, Feb 02, 2007 at 12:41:07PM -0800, David Daney wrote: > > I thought you were suggesting not saving s0-s7. If you don't save them, > > you cannot restore them. And they have to be restored from the > > sigcontext in the user's address space. This allows user space signal > > handlers to emulate trapping instructions, and the like. > > Not necessarily, because you can trust the signal handler to restore > them, and it can save them itself if it needs to. As I said, I think > there's at least one architecture which does it this way. I'm afraid I > don't know which one. Not saving the s-registers into the signal frame would be a neat optimization. It wouldn't only make things a little faster it would also free space in the signal frame which is needed for CPU architecture extensions that have more state to save. I had to burn almost the entire available space for the DSP extensions, so I wonder if we could get GDB to work? The alternative is probably a new version of the sigrestore. Ralf