Add earlysig test to check whether the pthread fork() wrapper

has a critical section where getting a signal causes a hang.  Based on
otto@ earlysig kernel regress; suggested by miod@

3 files changed, 95 insertions, 2 deletions

diff --git a/regress/lib/libpthread/Makefile b/regress/lib/libpthread/Makefile
index 2cdd9958cb0..9358149c4d3 100644
--- a/regress/lib/libpthread/Makefile
+++ b/regress/lib/libpthread/Makefile
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.42 2013/03/25 08:03:18 guenther Exp $
+# $OpenBSD: Makefile,v 1.43 2013/06/21 06:47:20 guenther Exp $
 
 # disabled because it requires a buggy behavior that uthread had:
 #	dup2_race
@@ -12,7 +12,8 @@
 #	blocked_fifo
 
 SUBDIR= barrier blocked_shutdown \
-	cancel cancel2 close close_race closefrom cwd errno execve fork \
+	cancel cancel2 close close_race closefrom cwd earlysig \
+	errno execve fork \
 	group malloc_duel netdb pcap poll preemption preemption_float \
 	pthread_atfork pthread_cond_timedwait pthread_create \
 	pthread_join pthread_kill pthread_mutex \
diff --git a/regress/lib/libpthread/earlysig/Makefile b/regress/lib/libpthread/earlysig/Makefile
new file mode 100644
index 00000000000..f18ead884e9
--- /dev/null
+++ b/regress/lib/libpthread/earlysig/Makefile
@@ -0,0 +1,5 @@
+# $OpenBSD: Makefile,v 1.1 2013/06/21 06:47:20 guenther Exp $
+
+PROG=	earlysig
+
+.include <bsd.regress.mk>
diff --git a/regress/lib/libpthread/earlysig/earlysig.c b/regress/lib/libpthread/earlysig/earlysig.c
new file mode 100644
index 00000000000..e65caaad53f
--- /dev/null
+++ b/regress/lib/libpthread/earlysig/earlysig.c
@@ -0,0 +1,87 @@
+/*	$OpenBSD: earlysig.c,v 1.1 2013/06/21 06:47:20 guenther Exp $	*/
+
+/*
+ * Public domain.  2005, Otto Moerbeek; 2013, Philip Guenther
+ *
+ * Try to create the case where a signal is delivered to a process before
+ * the pthread fork() wrapper can unlock the ld.so bind lock.
+ */
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/utsname.h>
+#include <sys/wait.h>
+
+#include <err.h>
+#include <pthread.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+void dohup(int signo)
+{
+	struct utsname name;
+	uname(&name);			/* anything that'll require binding */
+}
+
+void *tmain(void *arg)
+{
+	return (arg);
+}
+
+int
+main()
+{
+	pthread_t tid;
+	pid_t pid, rpid;
+	int r, status;
+
+	if (signal(SIGHUP, dohup) == SIG_ERR)
+		err(1, "signal");
+
+	/* make sure the thread library is fully active */
+	if ((r = pthread_create(&tid, NULL, tmain, NULL)))
+		errx(1, "pthread_create: %s", strerror(r));
+	pthread_join(tid, NULL);
+
+	/* make sure kill() and all the symbols in fork() are bound */
+	kill(0, 0);
+	if ((pid = fork()) <= 0) {
+		if (pid == -1)
+			err(1, "fork");
+		_exit(0);
+	}
+	if (waitpid(pid, &status, 0) == -1)
+		err(1, "waitpid");
+
+
+	switch(pid = fork()) {
+	case -1:
+		err(1, "fork");
+		break;
+	case 0:
+		sleep(2);
+		_exit(0);
+	default:
+		kill(pid, SIGHUP);
+		sleep(3);
+		if ((rpid = waitpid(pid, &status, WNOHANG)) == -1)
+			err(1, "waitpid");
+		if (rpid == 0) {
+			/* took too long */
+			kill(pid, SIGKILL);
+			if (waitpid(pid, &status, 0) == -1)
+				err(1, "waitpid");
+		}
+		if (WIFEXITED(status) && WEXITSTATUS(status) == 0)
+			exit(0);
+		else if (WIFEXITED(status))
+			errx(1, "child exited with status %d",
+			    WEXITSTATUS(status));
+		else if (WTERMSIG(status) == SIGKILL)
+			errx(1, "failed: child hung");
+		errx(1, "child killed by signal %d", WTERMSIG(status));
+	}
+}