kernel: add #0/brk and move brk_() to libc

qa/kern/brk.c

@@ -0,0 +1,46 @@
+/*
+ * This file is part of Jehanne.
+ *
+ * Copyright (C) 2016 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 <libc.h>
+
+void
+main(void)
+{
+	long b, b1;
+
+	b = create("#0/brk", -1, 16*1024*1024);
+	if(b >= 0){
+		print("FAIL: create returned fd %d.\n", b);
+		exits("FAIL");
+	}
+	if(b == -1){
+		print("FAIL: create: %r.\n");
+		exits("FAIL");
+	}
+	b1 = brk((void*)b + 16*1024*1024);
+	if(b1 == -1){
+		print("FAIL: brk: %r.\n");
+		exits("FAIL");
+	}
+	if(b >= b1){
+		print("FAIL: b >= b1.\n");
+		exits("FAIL");
+	}
+	print("PASS\n");
+	exits("PASS");
+}