From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752926Ab2HaNK3 (ORCPT ); Fri, 31 Aug 2012 09:10:29 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:41093 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752493Ab2HaNK2 (ORCPT ); Fri, 31 Aug 2012 09:10:28 -0400 Date: Fri, 31 Aug 2012 14:10:20 +0100 From: Al Viro To: Nobuhiro Iwamatsu Cc: Paul Mundt , Linux Kernel Mailing List Subject: Re: Can not get output of command line on SH Message-ID: <20120831131020.GB23464@ZenIV.linux.org.uk> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 31, 2012 at 04:32:45PM +0900, Nobuhiro Iwamatsu wrote: > Hi, Al. > > I can not get output of command line on SH in latest linux kernel. > I bisected, I confirmed that this problem occurred by following commit. > > ----- > commit 4a9d4b024a3102fc083c925c242d98ac27b1c5f6 > Author: Al Viro > Date: Sun Jun 24 09:56:45 2012 +0400 > > switch fput to task_work_add > For example ,when I input 'ls', nothing is displayed. > However, it is outputted when 'Ctrl+C' is inputted. > I checked other CPUs, it is only SH that this problem occurs. > > Paul, do you think about this? Smells like broken TIF_NOTIFY_RESUME hookup on sh... Arrrgh. Looks like while it is in the relevant masks *and* checked in do_notify_resume() both on 32bit and 64bit variants since commit ab99c733ae73cce31f2a2434f7099564e5a73d95 Author: Paul Mundt Date: Wed Jul 30 19:55:30 2008 +0900 sh: Make syscall tracer use tracehook notifiers, add TIF_NOTIFY_RESUME. they are actually *not* reached without simulataneous SIGPENDING, since the actual glue in the callers had not been updated back then and still checks for _TIF_SIGPENDING alone when deciding whether to hit do_notify_resume() or not. Looks like the following ought to fix that: Signed-off-by: Al Viro --- diff --git a/arch/sh/kernel/cpu/sh5/entry.S b/arch/sh/kernel/cpu/sh5/entry.S index b7cf6a5..7e605b9 100644 --- a/arch/sh/kernel/cpu/sh5/entry.S +++ b/arch/sh/kernel/cpu/sh5/entry.S @@ -933,7 +933,7 @@ ret_with_reschedule: pta restore_all, tr1 - movi _TIF_SIGPENDING, r8 + movi (_TIF_SIGPENDING|_TIF_NOTIFY_RESUME), r8 and r8, r7, r8 pta work_notifysig, tr0 bne r8, ZERO, tr0 diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S index f67601c..b96489d 100644 --- a/arch/sh/kernel/entry-common.S +++ b/arch/sh/kernel/entry-common.S @@ -139,7 +139,7 @@ work_pending: ! r8: current_thread_info ! t: result of "tst #_TIF_NEED_RESCHED, r0" bf/s work_resched - tst #_TIF_SIGPENDING, r0 + tst #(_TIF_SIGPENDING | _TIF_NOTIFY_RESUME), r0 work_notifysig: bt/s __restore_all mov r15, r4