Merge branch 'linus' into core/urgent

1 files changed, 64 insertions, 0 deletions

diff --git a/scripts/basic/hash.c b/scripts/basic/hash.c
new file mode 100644
index 000000000000..3299ad7fc8c0
--- /dev/null
+++ b/scripts/basic/hash.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2008 Red Hat, Inc., Jason Baron <jbaron@redhat.com>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define DYNAMIC_DEBUG_HASH_BITS 6
+
+static const char *program;
+
+static void usage(void)
+{
+	printf("Usage: %s <djb2|r5> <modname>\n", program);
+	exit(1);
+}
+
+/* djb2 hashing algorithm by Dan Bernstein. From:
+ * http://www.cse.yorku.ca/~oz/hash.html
+ */
+
+unsigned int djb2_hash(char *str)
+{
+	unsigned long hash = 5381;
+	int c;
+
+	c = *str;
+	while (c) {
+		hash = ((hash << 5) + hash) + c;
+		c = *++str;
+	}
+	return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1));
+}
+
+unsigned int r5_hash(char *str)
+{
+	unsigned long hash = 0;
+	int c;
+
+	c = *str;
+	while (c) {
+		hash = (hash + (c << 4) + (c >> 4)) * 11;
+		c = *++str;
+	}
+	return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1));
+}
+
+int main(int argc, char *argv[])
+{
+	program = argv[0];
+
+	if (argc != 3)
+		usage();
+	if (!strcmp(argv[1], "djb2"))
+		printf("%d\n", djb2_hash(argv[2]));
+	else if (!strcmp(argv[1], "r5"))
+		printf("%d\n", r5_hash(argv[2]));
+	else
+		usage();
+	exit(0);
+}
+