From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755910AbaDKLux (ORCPT ); Fri, 11 Apr 2014 07:50:53 -0400 Received: from mail-qc0-f177.google.com ([209.85.216.177]:52811 "EHLO mail-qc0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754664AbaDKLuv (ORCPT ); Fri, 11 Apr 2014 07:50:51 -0400 MIME-Version: 1.0 X-Originating-IP: [46.139.80.5] In-Reply-To: <20140411103351.GJ16119@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> Date: Fri, 11 Apr 2014 13:50:50 +0200 Message-ID: Subject: Re: [PATCH 02/15] arm: __NR_syscalls fix From: Miklos Szeredi To: Russell King - ARM Linux Cc: linux-arch , Kernel Mailing List , Miklos Szeredi Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 11, 2014 at 12:33 PM, Russell King - ARM Linux wrote: > On Fri, Apr 11, 2014 at 12:25:38PM +0200, Miklos Szeredi wrote: >> From: Miklos Szeredi >> >> Signed-off-by: Miklos Szeredi >> Cc: Russell King >> --- > > This has me wondering... > > (a) what you think it fixes > (b) whether you tried to build-test this > > The ARM instruction set supports 8-bit immediate constants with an even > power of two shift. 384 fits that (0x180), 382 does not (0x17e), and > in your following patch, 383 definitely doesn't (0x17f). > > Having this constant larger than necessary does not cause any problem > for the syscall table: we explicitly pad it with calls to sys_ni_syscall > to make up the difference. 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. Thanks, Miklos