qa: check devproc start/stop ctl msg

qa/kern/stop_start.c

@@ -0,0 +1,41 @@
+/*
+ * This file is part of Jehanne.
+ *
+ * Copyright (C) 2017 Giacomo Tesio <giacomo@tesio.it>
+ *
+ * Jehanne is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * Jehanne is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Jehanne.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <u.h>
+#include <lib9.h>
+
+void
+main(int argc, char**argv)
+{
+	int fd, n;
+	char *path;
+	
+	path = smprint("/proc/%d/ctl", getpid());
+	fd = open(path, OWRITE);
+	if(fd < 0){
+		print("FAIL: open");
+		exits("FAIL");
+	}
+	n = write(fd, "stop", 4);
+	if(n < 0){
+		print("FAIL: write");
+		exits("FAIL");
+	}
+	close(fd);
+	print("PASS\n");
+	exits("PASS");
+}