From owner-svn-src-head@FreeBSD.ORG Thu Sep 13 15:51:18 2012 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C4B091065672; Thu, 13 Sep 2012 15:51:18 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c]) by mx1.freebsd.org (Postfix) with ESMTP id 963418FC0A; Thu, 13 Sep 2012 15:51:18 +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 q8DFpIkU027968; Thu, 13 Sep 2012 15:51:18 GMT (envelope-from jhb@svn.freebsd.org) Received: (from jhb@localhost) by svn.freebsd.org (8.14.4/8.14.4/Submit) id q8DFpIQZ027965; Thu, 13 Sep 2012 15:51:18 GMT (envelope-from jhb@svn.freebsd.org) Message-Id: <201209131551.q8DFpIQZ027965@svn.freebsd.org> From: John Baldwin Date: Thu, 13 Sep 2012 15:51:18 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Subject: svn commit: r240467 - head/sys/kern X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 Sep 2012 15:51:18 -0000 Author: jhb Date: Thu Sep 13 15:51:18 2012 New Revision: 240467 URL: http://svn.freebsd.org/changeset/base/240467 Log: Ignore stop and continue signals sent to an exiting process. Stop signals set p_xstat to the signal that triggered the stop, but p_xstat is also used to hold the exit status of an exiting process. Without this change, a stop signal that arrived after a process was marked P_WEXIT but before it was marked a zombie would overwrite the exit status with the stop signal number. Reviewed by: kib MFC after: 1 week Modified: head/sys/kern/kern_exit.c head/sys/kern/kern_sig.c Modified: head/sys/kern/kern_exit.c ============================================================================== --- head/sys/kern/kern_exit.c Thu Sep 13 14:40:24 2012 (r240466) +++ head/sys/kern/kern_exit.c Thu Sep 13 15:51:18 2012 (r240467) @@ -200,6 +200,14 @@ exit1(struct thread *td, int rv) _STOPEVENT(p, S_EXIT, rv); /* + * Ignore any pending request to stop due to a stop signal. + * Once P_WEXIT is set, future requests will be ignored as + * well. + */ + p->p_flag &= ~P_STOPPED_SIG; + KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped")); + + /* * Note that we are exiting and do another wakeup of anyone in * PIOCWAIT in case they aren't listening for S_EXIT stops or * decided to wait again after we told them we are exiting. Modified: head/sys/kern/kern_sig.c ============================================================================== --- head/sys/kern/kern_sig.c Thu Sep 13 14:40:24 2012 (r240466) +++ head/sys/kern/kern_sig.c Thu Sep 13 15:51:18 2012 (r240467) @@ -2134,6 +2134,8 @@ tdsendsignal(struct proc *p, struct thre * We try do the per-process part here. */ if (P_SHOULDSTOP(p)) { + KASSERT(!(p->p_flag & P_WEXIT), + ("signal to stopped but exiting process")); if (sig == SIGKILL) { /* * If traced process is already stopped, @@ -2248,7 +2250,7 @@ tdsendsignal(struct proc *p, struct thre MPASS(action == SIG_DFL); if (prop & SA_STOP) { - if (p->p_flag & P_PPWAIT) + if (p->p_flag & (P_PPWAIT|P_WEXIT)) goto out; p->p_flag |= P_STOPPED_SIG; p->p_xstat = sig; @@ -2410,6 +2412,7 @@ ptracestop(struct thread *td, int sig) struct proc *p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); + KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, &p->p_mtx.lock_object, "Stopping for traced signal"); @@ -2648,7 +2651,7 @@ issignal(struct thread *td, int stop_all * process group, ignore tty stop signals. */ if (prop & SA_STOP) { - if (p->p_flag & P_TRACED || + if (p->p_flag & (P_TRACED|P_WEXIT) || (p->p_pgrp->pg_jobc == 0 && prop & SA_TTYSTOP)) break; /* == ignore */