Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * Copyright (C) 2008 Red Hat, Inc., Jason Baron <jbaron@redhat.com>
3 *
4 */
5
6#include <stdio.h>
7#include <stdlib.h>
8#include <string.h>
9
10#define DYNAMIC_DEBUG_HASH_BITS 6
11
12static const char *program;
13
14static void usage(void)
15{
16 printf("Usage: %s <djb2|r5> <modname>\n", program);
17 exit(1);
18}
19
20/* djb2 hashing algorithm by Dan Bernstein. From:
21 * http://www.cse.yorku.ca/~oz/hash.html
22 */
23
24static unsigned int djb2_hash(char *str)
25{
26 unsigned long hash = 5381;
27 int c;
28
29 c = *str;
30 while (c) {
31 hash = ((hash << 5) + hash) + c;
32 c = *++str;
33 }
34 return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1));
35}
36
37static unsigned int r5_hash(char *str)
38{
39 unsigned long hash = 0;
40 int c;
41
42 c = *str;
43 while (c) {
44 hash = (hash + (c << 4) + (c >> 4)) * 11;
45 c = *++str;
46 }
47 return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1));
48}
49
50int main(int argc, char *argv[])
51{
52 program = argv[0];
53
54 if (argc != 3)
55 usage();
56 if (!strcmp(argv[1], "djb2"))
57 printf("%d\n", djb2_hash(argv[2]));
58 else if (!strcmp(argv[1], "r5"))
59 printf("%d\n", r5_hash(argv[2]));
60 else
61 usage();
62 exit(0);
63}
64