Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763210AbXKNS6g (ORCPT ); Wed, 14 Nov 2007 13:58:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761761AbXKNS6T (ORCPT ); Wed, 14 Nov 2007 13:58:19 -0500 Received: from ns2.suse.de ([195.135.220.15]:56478 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761168AbXKNS6R (ORCPT ); Wed, 14 Nov 2007 13:58:17 -0500 Subject: patch uml-kill-subprocesses-on-exit.patch queued to -stable tree To: ytht.net@gmail.com, akpm@linux-foundation.org, gregkh@suse.de, jdike@linux.intel.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, user-mode-linux-devel@lists.sourceforge.net Cc: , From: Date: Wed, 14 Nov 2007 10:58:06 -0800 In-Reply-To: <20071101195327.GA8882@c2.user-mode-linux.org> Message-Id: <20071114185815.1B6CF14540D0@imap.suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4087 Lines: 118 This is a note to let you know that we have just queued up the patch titled Subject: UML - kill subprocesses on exit to the 2.6.23-stable tree. Its filename is uml-kill-subprocesses-on-exit.patch A git repo of this tree can be found at http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary >From stable-bounces@linux.kernel.org Thu Nov 1 12:54:06 2007 From: Lepton Wu Date: Thu, 1 Nov 2007 15:53:27 -0400 Subject: UML - kill subprocesses on exit To: stable@kernel.org Cc: LKML , uml-devel , Lepton Wu Message-ID: <20071101195327.GA8882@c2.user-mode-linux.org> Content-Disposition: inline From: Lepton Wu commit a24864a1d52a97e345a6bd4862a057f98364d098 uml: definitively kill subprocesses on panic In a stock 2.6.22.6 kernel, poweroff a user mode linux guest (2.6.22.6 running in skas0 mode) will halt the host linux. I think the reason is the kernel thread abort because of a bug. Then the sys_reboot in process of user mode linux guest is not trapped by the user mode linux kernel and is executed by host. I think it is better to make sure all of our children process to quit when user mode linux kernel abort. [ jdike - the kernel process needs to ignore SIGTERM, plus the waitpid/kill loop is needed to make sure that all of our children are dead before the kernel exits ] Signed-off-by: Lepton Wu Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/um/os-Linux/skas/process.c | 2 +- arch/um/os-Linux/util.c | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+), 1 deletion(-) --- a/arch/um/os-Linux/skas/process.c +++ b/arch/um/os-Linux/skas/process.c @@ -182,7 +182,7 @@ static int userspace_tramp(void *stack) ptrace(PTRACE_TRACEME, 0, 0, 0); - init_new_thread_signals(); + signal(SIGTERM, SIG_DFL); err = set_interval(1); if(err) panic("userspace_tramp - setting timer failed, errno = %d\n", --- a/arch/um/os-Linux/util.c +++ b/arch/um/os-Linux/util.c @@ -105,6 +105,44 @@ int setjmp_wrapper(void (*proc)(void *, void os_dump_core(void) { + int pid; + signal(SIGSEGV, SIG_DFL); + + /* + * We are about to SIGTERM this entire process group to ensure that + * nothing is around to run after the kernel exits. The + * kernel wants to abort, not die through SIGTERM, so we + * ignore it here. + */ + + signal(SIGTERM, SIG_IGN); + kill(0, SIGTERM); + /* + * Most of the other processes associated with this UML are + * likely sTopped, so give them a SIGCONT so they see the + * SIGTERM. + */ + kill(0, SIGCONT); + + /* + * Now, having sent signals to everyone but us, make sure they + * die by ptrace. Processes can survive what's been done to + * them so far - the mechanism I understand is receiving a + * SIGSEGV and segfaulting immediately upon return. There is + * always a SIGSEGV pending, and (I'm guessing) signals are + * processed in numeric order so the SIGTERM (signal 15 vs + * SIGSEGV being signal 11) is never handled. + * + * Run a waitpid loop until we get some kind of error. + * Hopefully, it's ECHILD, but there's not a lot we can do if + * it's something else. Tell os_kill_ptraced_process not to + * wait for the child to report its death because there's + * nothing reasonable to do if that fails. + */ + + while ((pid = waitpid(-1, NULL, WNOHANG)) > 0) + os_kill_ptraced_process(pid, 0); + abort(); } Patches currently in stable-queue which might be from ytht.net@gmail.com are queue-2.6.23/uml-kill-subprocesses-on-exit.patch - 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/