From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: [merged] usermodehelper-dont-use-clone_vfork-for-____call_usermodehelper.patch removed from -mm tree Date: Thu, 11 Dec 2014 11:08:04 -0800 Message-ID: <5489eb94.5OFd0YRb76LlVV80%akpm@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from mail.linuxfoundation.org ([140.211.169.12]:46055 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758579AbaLKTIF (ORCPT ); Thu, 11 Dec 2014 14:08:05 -0500 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: oleg@redhat.com, schwidefsky@de.ibm.com, mm-commits@vger.kernel.org The patch titled Subject: usermodehelper: don't use CLONE_VFORK for ____call_usermodehelper() has been removed from the -mm tree. Its filename was usermodehelper-dont-use-clone_vfork-for-____call_usermodehelper.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Oleg Nesterov Subject: usermodehelper: don't use CLONE_VFORK for ____call_usermodehelper() After "kernel/kmod: fix use-after-free of the sub_infostructure" CLONE_VFORK in __call_usermodehelper() buys nothing, we rely on on umh_complete() in ____call_usermodehelper() anyway. Remove it. This also eliminates the unnecessary sleep/wakeup in the likely case, and this allows the next change. While at it, kill the "int wait" locals in ____call_usermodehelper() and __call_usermodehelper(), they can safely use sub_info->wait. Signed-off-by: Oleg Nesterov Cc: Martin Schwidefsky Cc: Oleg Nesterov Signed-off-by: Andrew Morton --- kernel/kmod.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff -puN kernel/kmod.c~usermodehelper-dont-use-clone_vfork-for-____call_usermodehelper kernel/kmod.c --- a/kernel/kmod.c~usermodehelper-dont-use-clone_vfork-for-____call_usermodehelper +++ a/kernel/kmod.c @@ -223,7 +223,6 @@ static void umh_complete(struct subproce static int ____call_usermodehelper(void *data) { struct subprocess_info *sub_info = data; - int wait = sub_info->wait & ~UMH_KILLABLE; struct cred *new; int retval; @@ -267,7 +266,7 @@ static int ____call_usermodehelper(void out: sub_info->retval = retval; /* wait_for_helper() will call umh_complete if UHM_WAIT_PROC. */ - if (wait != UMH_WAIT_PROC) + if (!(sub_info->wait & UMH_WAIT_PROC)) umh_complete(sub_info); if (!retval) return 0; @@ -323,18 +322,13 @@ static void __call_usermodehelper(struct { struct subprocess_info *sub_info = container_of(work, struct subprocess_info, work); - int wait = sub_info->wait & ~UMH_KILLABLE; pid_t pid; - /* CLONE_VFORK: wait until the usermode helper has execve'd - * successfully We need the data structures to stay around - * until that is done. */ - if (wait == UMH_WAIT_PROC) + if (sub_info->wait & UMH_WAIT_PROC) pid = kernel_thread(wait_for_helper, sub_info, CLONE_FS | CLONE_FILES | SIGCHLD); else { - pid = kernel_thread(call_helper, sub_info, - CLONE_VFORK | SIGCHLD); + pid = kernel_thread(call_helper, sub_info, SIGCHLD); /* Worker thread stopped blocking khelper thread. */ kmod_thread_locker = NULL; } _ Patches currently in -mm which might be from oleg@redhat.com are origin.patch mmfs-introduce-helpers-around-the-i_mmap_mutex.patch mm-use-new-helper-functions-around-the-i_mmap_mutex.patch mm-convert-i_mmap_mutex-to-rwsem.patch mm-rmap-share-the-i_mmap_rwsem.patch uprobes-share-the-i_mmap_rwsem.patch mm-xip-share-the-i_mmap_rwsem.patch mm-memory-failure-share-the-i_mmap_rwsem.patch mm-nommu-share-the-i_mmap_rwsem.patch mm-memoryc-share-the-i_mmap_rwsem.patch remove-unnecessary-is_valid_nodemask.patch oom-dont-assume-that-a-coredumping-thread-will-exit-soon.patch oom-dont-assume-that-a-coredumping-thread-will-exit-soon-v2.patch oom-dont-assume-that-a-coredumping-thread-will-exit-soon-v2-fix.patch oom-kill-the-insufficient-and-no-longer-needed-pt_trace_exit-check.patch linux-next.patch all-arches-signal-move-restart_block-to-struct-task_struct.patch