From owner-svn-src-stable-8@FreeBSD.ORG Fri Nov 25 09:46:37 2011 Return-Path: Delivered-To: svn-src-stable-8@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 14EE1106566C; Fri, 25 Nov 2011 09:46:37 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c]) by mx1.freebsd.org (Postfix) with ESMTP id DE8F18FC16; Fri, 25 Nov 2011 09:46:36 +0000 (UTC) Received: from svn.freebsd.org (localhost [127.0.0.1]) by svn.freebsd.org (8.14.4/8.14.4) with ESMTP id pAP9kaaH036812; Fri, 25 Nov 2011 09:46:36 GMT (envelope-from kib@svn.freebsd.org) Received: (from kib@localhost) by svn.freebsd.org (8.14.4/8.14.4/Submit) id pAP9kaRX036809; Fri, 25 Nov 2011 09:46:36 GMT (envelope-from kib@svn.freebsd.org) Message-Id: <201111250946.pAP9kaRX036809@svn.freebsd.org> From: Konstantin Belousov Date: Fri, 25 Nov 2011 09:46:36 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-8@freebsd.org X-SVN-Group: stable-8 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Subject: svn commit: r227964 - in stable/8/sys: kern sys X-BeenThere: svn-src-stable-8@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for only the 8-stable src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 Nov 2011 09:46:37 -0000 Author: kib Date: Fri Nov 25 09:46:36 2011 New Revision: 227964 URL: http://svn.freebsd.org/changeset/base/227964 Log: MFC r227657: Consistently use process spin lock for protection of the p->p_boundary_count. Race could cause the execve(2) from the threaded process to hung since thread boundary counter was incorrect and single-threading never finished. Modified: stable/8/sys/kern/kern_thread.c stable/8/sys/sys/proc.h Directory Properties: stable/8/sys/ (props changed) Modified: stable/8/sys/kern/kern_thread.c ============================================================================== --- stable/8/sys/kern/kern_thread.c Fri Nov 25 07:11:02 2011 (r227963) +++ stable/8/sys/kern/kern_thread.c Fri Nov 25 09:46:36 2011 (r227964) @@ -518,6 +518,8 @@ calc_remaining(struct proc *p, int mode) { int remaining; + PROC_LOCK_ASSERT(p, MA_OWNED); + PROC_SLOCK_ASSERT(p, MA_OWNED); if (mode == SINGLE_EXIT) remaining = p->p_numthreads; else if (mode == SINGLE_BOUNDARY) @@ -767,8 +769,11 @@ thread_suspend_check(int return_instead) td->td_flags &= ~TDF_BOUNDARY; thread_unlock(td); PROC_LOCK(p); - if (return_instead == 0) + if (return_instead == 0) { + PROC_SLOCK(p); p->p_boundary_count--; + PROC_SUNLOCK(p); + } } return (0); } Modified: stable/8/sys/sys/proc.h ============================================================================== --- stable/8/sys/sys/proc.h Fri Nov 25 07:11:02 2011 (r227963) +++ stable/8/sys/sys/proc.h Fri Nov 25 09:46:36 2011 (r227964) @@ -527,7 +527,7 @@ struct proc { struct thread *p_singlethread;/* (c + j) If single threading this is it */ int p_suspcount; /* (j) Num threads in suspended mode. */ struct thread *p_xthread; /* (c) Trap thread */ - int p_boundary_count;/* (c) Num threads at user boundary */ + int p_boundary_count;/* (j) Num threads at user boundary */ int p_pendingcnt; /* how many signals are pending */ struct itimers *p_itimers; /* (c) POSIX interval timers. */ /* End area that is zeroed on creation. */