zdtm: new testcase for unhashed proc entries

Testcase: fork child, chdir into /proc/$pid and kill child.

test for http://bugzilla.openvz.org/show_bug.cgi?id=2315Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Andrey Wagin <avagin@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm/live/static/Makefile

@@ -62,6 +62,7 @@ TST_NOFILE	=				\
 		netns				\
 		session01			\
 		socket-ext			\
+		unhashed_proc			\
 #		jobctl00			\
 
 TST_FILE	=				\

test/zdtm/live/static/unhashed_proc.c

+#include <errno.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <string.h>
+#include <linux/limits.h>
+
+#include "zdtmtst.h"
+
+const char *test_doc	= "Chdir into unhashed proc entry";
+const char *test_author	= "Konstantin Khlebnikov <khlebnikov@openvz.org>";
+
+int main(int argc, char ** argv)
+{
+	int pid, len;
+	char cwd1[PATH_MAX], cwd2[PATH_MAX];
+
+	test_init(argc, argv);
+
+	pid = fork();
+	if (pid < 0) {
+		err("Fork failed %m\n");
+		exit(1);
+	} else if (!pid) {
+		pause();
+		return 0;
+	}
+
+	sprintf(cwd1, "/proc/%d", pid);
+
+	if (chdir(cwd1) < 0) {
+		kill(pid, SIGKILL);
+		err("Chdir failed %m\n");
+		exit(1);
+	}
+
+	kill(pid, SIGKILL);
+	waitpid(pid, NULL, 0);
+
+	if (getcwd(cwd1, sizeof(cwd1))) {
+		err("successfull getcwd: %s\n", cwd1);
+		exit(1);
+	} else if (errno != ENOENT) {
+		err("wrong errno: %m\n");
+		exit(1);
+	}
+
+	len = readlink("/proc/self/cwd", cwd1, sizeof(cwd1));
+	if (len < 0) {
+		err("can't read cwd symlink %m\n");
+		exit(1);
+	}
+	cwd1[len] = 0;
+
+	test_daemon();
+	test_waitsig();
+
+	if (getcwd(cwd2, sizeof(cwd2))) {
+		fail("successfull getcwd: %s\n", cwd2);
+		exit(1);
+	} else if (errno != ENOENT) {
+		fail("wrong errno: %m\n");
+		exit(1);
+	}
+
+	len = readlink("/proc/self/cwd", cwd2, sizeof(cwd2)-1);
+	if (len < 0) {
+		fail("can't read cwd symlink %m\n");
+		exit(1);
+	}
+	cwd2[len] = 0;
+
+	if (strcmp(cwd1, cwd2))
+		test_msg("cwd differs: %s != %s\n", cwd1, cwd2);
+
+	pass();
+
+	return 0;
+}