Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756880AbaDKMpn (ORCPT ); Fri, 11 Apr 2014 08:45:43 -0400 Received: from gw-1.arm.linux.org.uk ([78.32.30.217]:58397 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754442AbaDKMpl (ORCPT ); Fri, 11 Apr 2014 08:45:41 -0400 Date: Fri, 11 Apr 2014 13:45:02 +0100 From: Russell King - ARM Linux To: Miklos Szeredi , Wade Farnsworth , Al Viro Cc: linux-arch , Kernel Mailing List , Miklos Szeredi Subject: Re: [PATCH 02/15] arm: __NR_syscalls fix Message-ID: <20140411124502.GO16119@n2100.arm.linux.org.uk> References: <1397211951-20549-1-git-send-email-miklos@szeredi.hu> <1397211951-20549-3-git-send-email-miklos@szeredi.hu> <20140411103351.GJ16119@n2100.arm.linux.org.uk> <20140411115421.GL16119@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 11, 2014 at 02:02:32PM +0200, Miklos Szeredi wrote: > On Fri, Apr 11, 2014 at 1:54 PM, Russell King - ARM Linux > wrote: > > On Fri, Apr 11, 2014 at 01:50:50PM +0200, Miklos Szeredi wrote: > >> Yes, and the padding will be of wrong length if NR_syscalls is > >> incorrect (which may be Oopsable?). At least that is my impression > >> from a casual glance. > > > > Please explain. > > Look at ending lines of arch/arm/kernel/calls.S: if NR_syscalls is a > multiple of 4, then syscalls_padding will be zero. I.e. no padding > despite the fact that there is in fact only 382 system calls in table > and there should be 2 sys_ni_syscall pads. Hmm, it looks like you're right... this used to work fine until... commit 1f66e06fb6414732bef7bf4a071ef76a837badec Author: Wade Farnsworth Date: Fri Sep 7 18:18:25 2012 +0100 ARM: 7524/1: support syscall tracing because the tracing code wanted to know the number of syscalls. I don't know what the answer is here, because the current solution is IMHO far to fragile. -- FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly improving, and getting towards what was expected from it. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/