Replace the old and extremely icky Mach/NetBSD allocator with a similarly

compact and much better one donated by Matt Dillon.  Implement a simple
sbrk() which uses the existing setheap() api.

Remove the custom allocator from the UFS code.  It wasn't working quite
right, and it shouldn't be needed with the new allocator.

Fix a serious problem with changing the value of already-existent
environment variables.  Don't attempt to modify the supposedly-const
argument to putenv()

Fix an off-by-one sizing error in the zipfs code detected by the new
allocator.

Submitted by:	zmalloc from Matt Dillon <dillon@backplane.com>

1 files changed, 60 insertions, 0 deletions

diff --git a/lib/libstand/sbrk.c b/lib/libstand/sbrk.c
new file mode 100644
index 0000000..0655c9a
--- /dev/null
+++ b/lib/libstand/sbrk.c
@@ -0,0 +1,60 @@
+/*-
+ * Copyright (c) 1998 Michael Smith
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	$Id$
+ */
+
+/*
+ * Minimal sbrk() emulation required for malloc support.
+ */
+
+#include <string.h>
+#include "stand.h"
+
+static size_t	maxheap, heapsize = 0;
+static void	*heapbase;
+
+void
+setheap(void *base, void *top)
+{
+    heapbase = base;
+    maxheap = top - base;
+}
+
+char *
+sbrk(int incr)
+{
+    char	*ret;
+    
+    if ((heapsize + incr) <= maxheap) {
+	ret = heapbase + heapsize;
+	bzero(ret, incr);
+	heapsize += incr;
+	return(ret);
+    }
+    errno = ENOMEM;
+    return((char *)-1);
+}
+