From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753926Ab1HLR76 (ORCPT ); Fri, 12 Aug 2011 13:59:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58423 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753612Ab1HLR75 (ORCPT ); Fri, 12 Aug 2011 13:59:57 -0400 Date: Fri, 12 Aug 2011 19:56:46 +0200 From: Oleg Nesterov To: Tejun Heo , Linus Torvalds Cc: Roland McGrath , Denys Vlasenko , KOSAKI Motohiro , Matt Fleming , linux-kernel@vger.kernel.org, Pavel Machek Subject: [PATCH 3/3] coredump_wait: don't call complete_vfork_done() Message-ID: <20110812175646.GD7484@redhat.com> References: <20110727163159.GA23785@redhat.com> <20110729192358.GB31717@mtj.dyndns.org> <20110812175550.GA7484@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110812175550.GA7484@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now that CLONE_VFORK is killable, coredump_wait() no longer needs complete_vfork_done(). zap_threads() should find and kill all tasks with the same ->mm, this includes our parent if ->vfork_done is set. mm_release() becomes the only caller, unexport complete_vfork_done(). Signed-off-by: Oleg Nesterov --- include/linux/sched.h | 1 - fs/exec.c | 14 ++------------ kernel/fork.c | 2 +- 3 files changed, 3 insertions(+), 14 deletions(-) --- 3.1/include/linux/sched.h~3_coredump_no_vfork_done 2011-08-12 18:50:11.000000000 +0200 +++ 3.1/include/linux/sched.h 2011-08-12 18:51:13.000000000 +0200 @@ -2254,7 +2254,6 @@ extern int do_execve(const char *, const char __user * const __user *, const char __user * const __user *, struct pt_regs *); extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *); -extern void complete_vfork_done(struct task_struct *tsk); struct task_struct *fork_idle(int); extern void set_task_comm(struct task_struct *tsk, char *from); --- 3.1/fs/exec.c~3_coredump_no_vfork_done 2011-08-12 18:50:11.000000000 +0200 +++ 3.1/fs/exec.c 2011-08-12 18:51:13.000000000 +0200 @@ -1925,19 +1925,9 @@ static int coredump_wait(int exit_code, core_waiters = zap_threads(tsk, mm, core_state, exit_code); up_write(&mm->mmap_sem); - if (unlikely(core_waiters < 0)) - goto fail; - - /* - * Make sure nobody is waiting for us to release the VM, - * otherwise we can deadlock when we wait on each other - */ - if (tsk->vfork_done) - complete_vfork_done(tsk); - - if (core_waiters) + if (core_waiters > 0) wait_for_completion(&core_state->startup); -fail: + return core_waiters; } --- 3.1/kernel/fork.c~3_coredump_no_vfork_done 2011-08-12 18:50:11.000000000 +0200 +++ 3.1/kernel/fork.c 2011-08-12 18:51:13.000000000 +0200 @@ -650,7 +650,7 @@ struct mm_struct *get_task_mm(struct tas } EXPORT_SYMBOL_GPL(get_task_mm); -void complete_vfork_done(struct task_struct *tsk) +static void complete_vfork_done(struct task_struct *tsk) { struct completion *vfork;