From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:46818 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752296AbdFMHWp (ORCPT ); Tue, 13 Jun 2017 03:22:45 -0400 Subject: Patch "kthread: fix boot hang (regression) on MIPS/OpenRISC" has been added to the 4.11-stable tree To: vegard.nossum@oracle.com, gregkh@linuxfoundation.org, jamie.iles@oracle.com, jonas@southpole.se, linux@roeck-us.net, oleg@redhat.com, ralf@linux-mips.org, shorne@gmail.com, stefan.kristiansson@saunalahti.fi, tglx@linutronix.de, torvalds@linux-foundation.org Cc: , From: Date: Tue, 13 Jun 2017 09:22:37 +0200 Message-ID: <14973385571247@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled kthread: fix boot hang (regression) on MIPS/OpenRISC to the 4.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kthread-fix-boot-hang-regression-on-mips-openrisc.patch and it can be found in the queue-4.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From b0f5a8f32e8bbdaae1abb8abe2d3cbafaba57e08 Mon Sep 17 00:00:00 2001 From: Vegard Nossum Date: Mon, 29 May 2017 09:22:07 +0200 Subject: kthread: fix boot hang (regression) on MIPS/OpenRISC From: Vegard Nossum commit b0f5a8f32e8bbdaae1abb8abe2d3cbafaba57e08 upstream. This fixes a regression in commit 4d6501dce079 where I didn't notice that MIPS and OpenRISC were reinitialising p->{set,clear}_child_tid to NULL after our initialisation in copy_process(). We can simply get rid of the arch-specific initialisation here since it is now always done in copy_process() before hitting copy_thread{,_tls}(). Review notes: - As far as I can tell, copy_process() is the only user of copy_thread_tls(), which is the only caller of copy_thread() for architectures that don't implement copy_thread_tls(). - After this patch, there is no arch-specific code touching p->set_child_tid or p->clear_child_tid whatsoever. - It may look like MIPS/OpenRISC wanted to always have these fields be NULL, but that's not true, as copy_process() would unconditionally set them again _after_ calling copy_thread_tls() before commit 4d6501dce079. Fixes: 4d6501dce079c1eb6bf0b1d8f528a5e81770109e ("kthread: Fix use-after-free if kthread fork fails") Reported-by: Guenter Roeck Tested-by: Guenter Roeck # MIPS only Acked-by: Stafford Horne Acked-by: Oleg Nesterov Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: Jonas Bonn Cc: Stefan Kristiansson Cc: openrisc@lists.librecores.org Cc: Jamie Iles Cc: Thomas Gleixner Signed-off-by: Vegard Nossum Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/mips/kernel/process.c | 1 - arch/openrisc/kernel/process.c | 2 -- 2 files changed, 3 deletions(-) --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -120,7 +120,6 @@ int copy_thread(unsigned long clone_flag struct thread_info *ti = task_thread_info(p); struct pt_regs *childregs, *regs = current_pt_regs(); unsigned long childksp; - p->set_child_tid = p->clear_child_tid = NULL; childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32; --- a/arch/openrisc/kernel/process.c +++ b/arch/openrisc/kernel/process.c @@ -167,8 +167,6 @@ copy_thread(unsigned long clone_flags, u top_of_kernel_stack = sp; - p->set_child_tid = p->clear_child_tid = NULL; - /* Locate userspace context on stack... */ sp -= STACK_FRAME_OVERHEAD; /* redzone */ sp -= sizeof(struct pt_regs); Patches currently in stable-queue which might be from vegard.nossum@oracle.com are queue-4.11/kthread-fix-boot-hang-regression-on-mips-openrisc.patch queue-4.11/kthread-fix-use-after-free-if-kthread-fork-fails.patch