From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 20 Jan 2004 19:39:24 +0000 (GMT) Received: from nevyn.them.org ([IPv6:::ffff:66.93.172.17]:50319 "EHLO nevyn.them.org") by linux-mips.org with ESMTP id ; Tue, 20 Jan 2004 19:39:24 +0000 Received: from drow by nevyn.them.org with local (Exim 4.30 #1 (Debian)) id 1Aj1iY-0007kl-PL; Tue, 20 Jan 2004 14:39:18 -0500 Date: Tue, 20 Jan 2004 14:39:18 -0500 From: Daniel Jacobowitz To: Ralf Baechle Cc: Pavel Kiryukhin , linux-mips@linux-mips.org Subject: Re: __MIPSEL__ in sys32_rt_sigtimedwait Message-ID: <20040120193918.GA2108@nevyn.them.org> References: <400D6877.1000105@dev.rtsoft.ru> <20040120183157.GB5495@linux-mips.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040120183157.GB5495@linux-mips.org> User-Agent: Mutt/1.5.1i 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: 4074 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: dan@debian.org Precedence: bulk X-list: linux-mips On Tue, Jan 20, 2004 at 07:31:57PM +0100, Ralf Baechle wrote: > On Tue, Jan 20, 2004 at 08:42:15PM +0300, Pavel Kiryukhin wrote: > > > Hi all, > > my question - does endiannes matters in sigset translation in > > sys32_rt_sigtimedwait (arch/mips/signal32.c)? > > Think about where bit 33 ends for a big endian machine with an without > the conversion. No, I'm pretty sure Pavel's right. -#ifdef __MIPSEB__ case 1: these.sig[0] = these32.sig[0] | (((long)these32.sig[1]) << 32); -#endif -#ifdef __MIPSEL__ - case 1: these.sig[0] = these32.sig[1] | (((long)these32.sig[0]) << 32); -#endif Consider a 64-bit sigset. 32-bit userland, 64-bit kernel. Here's a userland sigset with signal 33 set, only, on a little endian target. Word 1, least significant bit, right? byte address in memory 1 2 3 4 5 6 7 8 val 0 0 0 0 0 0 0 1 Obviously, as a 64-bit integer the sigset looks different. There it's supposed to be 1 << (33 - 1). val 0 0 0 1 0 0 0 0 So the correct algorithm to convert a userspace sigset to a kernel sigset is to shift the second word left 32 bits, and leave the first word right aligned, and or them together. Which is what using the __MIPSEB__ case does. -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer