--- ptrace-vfork-traceme.c-orig	2008-10-27 15:41:51.000000000 +0100
+++ ptrace-vfork-traceme.c	2008-10-27 15:47:05.000000000 +0100
@@ -18,14 +18,23 @@ do { \
 static void child_exit(int sig)
 {
 	int status;
+#if 0 /* Correct behavior.  */
 	printf("failure, child exited with %i: %s\n", sig, strsignal(sig));
+#endif
 	printf("wait() = %i\n", wait(&status));
-	printf("status = %i\n", status);
+	printf("status = 0x%x\n", status);
 	printf("\tWIFEXITED = %i\n", WIFEXITED(status));
 	printf("\tWEXITSTATUS = %i\n", WEXITSTATUS(status));
 	printf("\tWIFSIGNALED = %i\n", WIFSIGNALED(status));
 	printf("\tWTERMSIG = %i (%s)\n", WTERMSIG(status), strsignal(WTERMSIG(status)));
+	/* WIFSTOPPED happens.  */
+	printf("\tWIFSTOPPED = %i\n", WIFSTOPPED(status));
+	/* SIGTRAP happens.  */
+	printf("\tWSTOPSIG = %i (%s)\n", WSTOPSIG(status), strsignal(WSTOPSIG(status)));
+#if 0 /* We can continue.  Just calling printf() from a signal handler is not
+	 correct.  */
 	exit(1);
+#endif
 }
 
 int main(int argc, char *argv[])
@@ -35,9 +44,15 @@ int main(int argc, char *argv[])
 
 	/* child process ... shouldnt be executed, but just in case ... */
 	if (argc > 1 && !strcmp(argv[1], "child"))
+#if 0 /* Parent did not kill us, after its child_exit() messages we should get
+         here.  */
 		fail("kernel should have halted me...");
+#else
+		{ puts ("child exiting"); exit (0); }
+#endif
 
-	pid = vfork();
+	/* vfork() child must not call ptrace().  */
+	pid = fork();
 	if (pid == -1)
 		fail("vfork() didnt work: %m");
 	else if (!pid) {
@@ -54,6 +69,10 @@ int main(int argc, char *argv[])
 	/* do the parent stuff here */
 	signal(SIGCHLD, child_exit);
 
+	/* We cannot PTRACE_PEEKUSER here as the child still may not have
+	   called PTRACE_TRACEME.  */
+	pause ();
+
 	errno = 0;
 	pret = ptrace(PTRACE_PEEKUSER, pid, NULL, NULL);
 	if (pret && errno)