From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 18 Apr 2007 12:30:51 +0100 (BST) Received: from localhost.localdomain ([127.0.0.1]:54679 "EHLO dl5rb.ham-radio-op.net") by ftp.linux-mips.org with ESMTP id S20021716AbXDRLat (ORCPT ); Wed, 18 Apr 2007 12:30:49 +0100 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 l3IBUlNR020490; Wed, 18 Apr 2007 12:30:47 +0100 Received: (from ralf@localhost) by denk.linux-mips.net (8.13.8/8.13.8/Submit) id l3IBUkYM020488; Wed, 18 Apr 2007 12:30:46 +0100 Date: Wed, 18 Apr 2007 12:30:46 +0100 From: Ralf Baechle To: Atsushi Nemoto Cc: linux-mips@linux-mips.org Subject: Re: [PATCH] Retry {save,restore}_fp_context if failed in atomic context. Message-ID: <20070418113046.GC3938@linux-mips.org> References: <20070416.231944.41198415.anemo@mba.ocn.ne.jp> <20070416.233235.75185596.anemo@mba.ocn.ne.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070416.233235.75185596.anemo@mba.ocn.ne.jp> 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: 14874 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 Mon, Apr 16, 2007 at 11:32:35PM +0900, Atsushi Nemoto wrote: > > The save_fp_context()/restore_fp_context() might sleep on accessing > > user stack and therefore might lose FPU ownership in middle of them. > > > > If these function failed due to "in_atomic" test in do_page_fault, > > touch the sigcontext area in non-atomic context and retry these > > save/restore operation. > > > > This is a replacement of a (broken) fix which was titled "Allow CpU > > exception in kernel partially". > > > > Signed-off-by: Atsushi Nemoto > > And this is for 2.6.20-stable. Both applied, also to older -stable branches except 2.6.16. In case of 2.6.16 it would have been more time consuming than justifyable and since the bug this patch fixes is comparable to what we had before starting the whole surgery I have no problem to leave 2.6.16 as it is. Anybody still using 2.6.16 should upgrade anyway ... Ralf