Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262416AbVEMQHM (ORCPT ); Fri, 13 May 2005 12:07:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262419AbVEMQHL (ORCPT ); Fri, 13 May 2005 12:07:11 -0400 Received: from dgate1.fujitsu-siemens.com ([217.115.66.35]:55195 "EHLO dgate1.fujitsu-siemens.com") by vger.kernel.org with ESMTP id S262415AbVEMQG6 (ORCPT ); Fri, 13 May 2005 12:06:58 -0400 X-SBRSScore: None X-IronPort-AV: i="3.93,107,1114984800"; d="scan'208"; a="9296951:sNHT29356740" Message-ID: <4284D0A0.5010809@fujitsu-siemens.com> Date: Fri, 13 May 2005 18:06:56 +0200 From: Bodo Stroesser User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.3) Gecko/20040913 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Martin Schwidefsky CC: linux-kernel@vger.kernel.org, Ulrich Weigand Subject: Re: Again: UML on s390 (31Bit) References: In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1408 Lines: 39 Martin Schwidefsky wrote: >>Each time when the kernel is entered again and a signal is pending, >>do_signal() will be called on return to user with regs->trap setup >>freshly. So, I still believe the patch doesn't have *any* effect. > > > Oh, the patch does have an effect for the debugger. If the debugger > stopped on the sys_sig_return system call and does e.g. an inferior > function call, then the kernel might want to restart a system call > that isn't there because the debugger did a "jump" but could not > change regs->trap. AFAICS, it not even has an effect for the debugger. do_signal() is the only routine, that examines regs->trap. On each kernel-entry, regs->trap is set freshly. What will be the effect of changing it *after* it had been examined? The only exceptions are sys_(rt_)sigsuspend. Here do_signal() might be called twice, while *and* after processing the syscall. But even here the patch has no effect, as regs->gprs[2] contains -EINTR, if so_signal is called by sys_(rt_)sigreturn. Regards Bodo > > blue skies, > Martin > > Martin Schwidefsky > Linux for zSeries Development & Services > IBM Deutschland Entwicklung GmbH > - 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/