From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.12] helo=sc8-sf-mx2.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1CP8Iz-0004Eg-En for user-mode-linux-devel@lists.sourceforge.net; Tue, 02 Nov 2004 15:43:13 -0800 Received: from mailgate2.uni-paderborn.de ([131.234.22.35]) by sc8-sf-mx2.sourceforge.net with esmtp (TLSv1:AES256-SHA:256) (Exim 4.41) id 1CP8Iy-00084v-7t for user-mode-linux-devel@lists.sourceforge.net; Tue, 02 Nov 2004 15:43:13 -0800 Message-ID: <41881BA8.80102@upb.de> From: =?ISO-8859-1?Q?Sven_K=F6hler?= MIME-Version: 1.0 References: <20041029092641.8558.qmail@web26102.mail.ukl.yahoo.com> <200411021952.09095.blaisorblade_spam@yahoo.it> In-Reply-To: <200411021952.09095.blaisorblade_spam@yahoo.it> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: [uml-devel] Re: Stop at startup on 2.6 NPTL hosts Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Wed, 03 Nov 2004 00:43:36 +0100 To: Blaisorblade Cc: user-mode-linux-devel@lists.sourceforge.net, Jeff Dike , Roland Kaeser , Nuno Silva , Antoine Martin , Dennis Muhlestein > It is one UML bug I've just identified and that I'm trying to fix. This is the > faulty code, from arch/um/kernel/skas/process.c: > > static int userspace_tramp(void *arg) > { > init_new_thread_signals(0); > enable_timer(); > ptrace(PTRACE_TRACEME, 0, 0, 0); > tkill(gettid(), SIGSTOP); > os_stop_process(os_getpid()); > return(0); > } > > This is executed by a clone() child. What happens is that, with NPTL, both the > father and the son have the same pid, so the SIGSTOP is routed to the wrong > thread. However, this is not expected: having the same pid should be reserved > to when clone is called with CLONE_THREAD in the flags. I've verified that > this is not happening in this case, even with strace (to make sure glibc is > not playing any dirty tricks). But for some reasons, the kernel is behaving > as if this happened. This does remind me of something. I've already read the whole thing with CLONE_THREAD and clone() somewhere else, but i can't remember where it was. Was it on UML-MailingLists? Or was it even on the LKML? If my brain would just be a bit more reliable :-( ------------------------------------------------------- This SF.Net email is sponsored by: Sybase ASE Linux Express Edition - download now for FREE LinuxWorld Reader's Choice Award Winner for best database on Linux. http://ads.osdn.com/?ad_id=5588&alloc_id=12065&op=click _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel