--- /dev/null
+++ libmalloc/libmalloc-317.140.5/src/malloc_common.c
@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2018 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+#include "internal.h"
+
+#pragma mark -
+#pragma mark Utility Functions
+
+// libplatform does not have strstr() and we don't want to add any new
+// dependencies on libc, so we have to implement a version of strntr()
+// here. Fortunately, as it's only used to look for boot arguments, it does not
+// have to be efficient. We can also assume that the source string is
+// nul-terminated. Eventually, we will move the function to a more central
+// location and use it to replace other uses of strstr().
+const char *
+malloc_common_strstr(const char *src, const char *target, size_t target_len)
+{
+	const char *next = src;
+	while (*next) {
+		if (!strncmp(next, target, target_len)) {
+			return next;
+		}
+		next++;
+	}
+	return NULL;
+}
+
+// Converts a string to a long. If a non-numeric value is found, the
+// return value is whatever has been accumulated so far. end_ptr always points
+// to the character that caused the conversion to stop. We can't use strtol()
+// etc because that would add a new dependency on libc. Eventually, this
+// function could be made generally available within the library and used to
+// replace the existing calls to strtol(). Currenly only handles non-negative
+// numbers and does not detect overflow.
+long
+malloc_common_convert_to_long(const char *ptr, const char **end_ptr)
+{
+	long value = 0;
+	while (*ptr) {
+		char c = *ptr;
+		if (c < '0' || c > '9') {
+			break;
+		}
+		value = value * 10 + (c - '0');
+		ptr++;
+	}
+	*end_ptr = ptr;
+	return value;
+}
+
+// Looks for a sequence of the form "key=value" in the string 'src' and
+// returns the location of the first character of 'value', or NULL if not
+// found. No spaces are permitted around the "=".
+const char *
+malloc_common_value_for_key(const char *src, const char *key)
+{
+	const char *ptr = src;
+	size_t keylen = strlen(key);
+	while ((ptr = malloc_common_strstr(ptr, key, keylen)) != NULL) {
+		ptr += keylen;
+		if (*ptr == '=') {
+			return ptr + 1;
+		}
+	}
+	return NULL;
+}
+
+// Looks for a sequence of the form "key=value" in the string 'src' and
+// returns the location of the first character of 'value'. No spaces are
+// permitted around the "=". The value is copied to 'bufp', up to the first
+// whitespace or nul character and bounded by maxlen, and nul-terminated.
+// Returns bufp if the key was found, NULL if not.
+const char *
+malloc_common_value_for_key_copy(const char *src, const char *key,
+							   char *bufp, size_t maxlen)
+{
+	const char *ptr = malloc_common_value_for_key(src, key);
+	if (ptr) {
+		char *to = bufp;
+		while (maxlen > 1) { // Always leave room for a '\0'
+			char c = *ptr++;
+			if (c == '\0' || c == ' ' || c == '\t' || c == '\n') {
+				break;
+			}
+			*to++ = c;
+			maxlen--;
+		}
+		*to = '\0';	// Always nul-terminate
+		return bufp;
+	}
+	return NULL;
+}
+
+