diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-05-20 01:56:13 +0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-05-20 01:56:13 +0400 |
commit | 98a38a5d60a6e79eaad7f4a9b68cc1bd306ac5c0 (patch) | |
tree | bc6e761e7ead6b877c28abe908eaf9745c4f8627 /lib/bsearch.c | |
parent | 7663164f2619e37a1dcad59383e2fcf8c5194107 (diff) | |
parent | f721a465cddbe7f03e6cd2272008da558cf93818 (diff) | |
download | linux-98a38a5d60a6e79eaad7f4a9b68cc1bd306ac5c0.tar.xz |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
params.c: Use new strtobool function to process boolean inputs
debugfs: move to new strtobool
Add a strtobool function matching semantics of existing in kernel equivalents
modpost: Update 64k section support for binutils 2.18.50
module: Use binary search in lookup_symbol()
module: Use the binary search for symbols resolution
lib: Add generic binary search function to the kernel.
module: Sort exported symbols
module: each_symbol_section instead of each_symbol
module: split unset_section_ro_nx function.
module: undo module RONX protection correctly.
module: zero mod->init_ro_size after init is freed.
minor ANSI prototype sparse fix
module: reorder kparam_array to remove alignment padding on 64 bit builds
module: remove 64 bit alignment padding from struct module with CONFIG_TRACE*
module: do not hide __modver_version_show declaration behind ifdef
module: deal with alignment issues in built-in module versions
Diffstat (limited to 'lib/bsearch.c')
-rw-r--r-- | lib/bsearch.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/lib/bsearch.c b/lib/bsearch.c new file mode 100644 index 000000000000..5b54758e2afb --- /dev/null +++ b/lib/bsearch.c @@ -0,0 +1,53 @@ +/* + * A generic implementation of binary search for the Linux kernel + * + * Copyright (C) 2008-2009 Ksplice, Inc. + * Author: Tim Abbott <tabbott@ksplice.com> + * + * This program 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. + */ + +#include <linux/module.h> +#include <linux/bsearch.h> + +/* + * bsearch - binary search an array of elements + * @key: pointer to item being searched for + * @base: pointer to first element to search + * @num: number of elements + * @size: size of each element + * @cmp: pointer to comparison function + * + * This function does a binary search on the given array. The + * contents of the array should already be in ascending sorted order + * under the provided comparison function. + * + * Note that the key need not have the same type as the elements in + * the array, e.g. key could be a string and the comparison function + * could compare the string with the struct's name field. However, if + * the key and elements in the array are of the same type, you can use + * the same comparison function for both sort() and bsearch(). + */ +void *bsearch(const void *key, const void *base, size_t num, size_t size, + int (*cmp)(const void *key, const void *elt)) +{ + size_t start = 0, end = num; + int result; + + while (start < end) { + size_t mid = start + (end - start) / 2; + + result = cmp(key, base + mid * size); + if (result < 0) + end = mid; + else if (result > 0) + start = mid + 1; + else + return (void *)base + mid * size; + } + + return NULL; +} +EXPORT_SYMBOL(bsearch); |