[src/trunk]: src/sys/kern Disable PTRACE_FORK for vforked() children, because...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3a8bcca59b64
branches:  trunk
changeset: 773433:3a8bcca59b64
user:      christos <christos%NetBSD.org@localhost>
date:      Thu Feb 02 02:44:06 2012 +0000

description:
Disable PTRACE_FORK for vforked() children, because the parent is waiting
and will not receive the SIGTRAP in time.

diffstat:

 sys/kern/kern_fork.c |  10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)

diffs (32 lines):

diff -r 7f3bfe2869b2 -r 3a8bcca59b64 sys/kern/kern_fork.c
--- a/sys/kern/kern_fork.c      Wed Feb 01 23:43:49 2012 +0000
+++ b/sys/kern/kern_fork.c      Thu Feb 02 02:44:06 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_fork.c,v 1.186 2011/09/02 20:06:29 christos Exp $ */
+/*     $NetBSD: kern_fork.c,v 1.187 2012/02/02 02:44:06 christos Exp $ */
 
 /*-
  * Copyright (c) 1999, 2001, 2004, 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -67,7 +67,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_fork.c,v 1.186 2011/09/02 20:06:29 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_fork.c,v 1.187 2012/02/02 02:44:06 christos Exp $");
 
 #include "opt_ktrace.h"
 
@@ -460,8 +460,12 @@
        LIST_INSERT_HEAD(&parent->p_children, p2, p_sibling);
        p2->p_exitsig = exitsig;                /* signal for parent on exit */
 
+       /*
+        * We don't want to tracefork vfork()ed processes because they
+        * will not receive the SIGTRAP until it is too late.
+        */
        tracefork = (p1->p_slflag & (PSL_TRACEFORK|PSL_TRACED)) ==
-           (PSL_TRACEFORK|PSL_TRACED);
+           (PSL_TRACEFORK|PSL_TRACED) && (flags && FORK_PPWAIT) == 0;
        if (tracefork) {
                p2->p_slflag |= PSL_TRACED;
                p2->p_opptr = p2->p_pptr;