Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753660Ab3JDRYu (ORCPT ); Fri, 4 Oct 2013 13:24:50 -0400 Received: from mail-ie0-f173.google.com ([209.85.223.173]:37030 "EHLO mail-ie0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751642Ab3JDRYt (ORCPT ); Fri, 4 Oct 2013 13:24:49 -0400 MIME-Version: 1.0 In-Reply-To: <20130918095003.GB1783@mudshark.cambridge.arm.com> References: <20130917215749.GA11109@obsidianresearch.com> <20130918091748.GA1783@mudshark.cambridge.arm.com> <20130918095003.GB1783@mudshark.cambridge.arm.com> Date: Fri, 4 Oct 2013 19:24:48 +0200 Message-ID: Subject: Re: Commit breaks strace: ARM: entry: allow ARM-private syscalls to be restarted From: Arokux X To: Will Deacon Cc: Jason Gunthorpe , Russell King , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1902 Lines: 45 On Wed, Sep 18, 2013 at 11:50 AM, Will Deacon wrote: > On Wed, Sep 18, 2013 at 10:17:48AM +0100, Will Deacon wrote: >> On Tue, Sep 17, 2013 at 10:57:49PM +0100, Jason Gunthorpe wrote: >> > This happens with the latest git head for strace, as well as the 4.7 >> > release. >> > >> > Hopefully you can cook up a fix :) >> >> I'll take a look today, thanks. > > Ok, looks like the backwards branch to the syscall dispatching logic from > the trace entry is busted. Can you try the patch below please? > > I might also take a look at unifying the function prototypes for arm_syscall > and syscall_trace_enter, since it should help us remove some of the argument > shuffling in the trace path. > > Will > > --->8 > > diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S > index 74ad15d1..bc6bd96 100644 > --- a/arch/arm/kernel/entry-common.S > +++ b/arch/arm/kernel/entry-common.S > @@ -442,10 +442,10 @@ local_restart: > ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine > > add r1, sp, #S_OFF > - cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE) > +2: cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE) > eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back > bcs arm_syscall > -2: mov why, #0 @ no longer a real syscall > + mov why, #0 @ no longer a real syscall > b sys_ni_syscall @ not private func > > #if defined(CONFIG_OABI_COMPAT) || !defined(CONFIG_AEABI) Just stumbled upon the same issue. The patch seems to cure the problem. Thanks. -- 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/