1055 lines
22 KiB
C
1055 lines
22 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/lib/string.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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/*
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* stupid library routines.. The optimized versions should generally be found
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* as inline code in <asm-xx/string.h>
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*
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* These are buggy as well..
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*
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* * Fri Jun 25 1999, Ingo Oeser <ioe@informatik.tu-chemnitz.de>
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* - Added strsep() which will replace strtok() soon (because strsep() is
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* reentrant and should be faster). Use only strsep() in new code, please.
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*
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* * Sat Feb 09 2002, Jason Thomas <jason@topic.com.au>,
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* Matthew Hawkins <matt@mh.dropbear.id.au>
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* - Kissed strtok() goodbye
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*/
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/ctype.h>
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/bug.h>
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#include <linux/errno.h>
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#include <asm/byteorder.h>
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#include <asm/word-at-a-time.h>
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#include <asm/page.h>
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#ifndef __HAVE_ARCH_STRNCASECMP
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/**
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* strncasecmp - Case insensitive, length-limited string comparison
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* @s1: One string
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* @s2: The other string
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* @len: the maximum number of characters to compare
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*/
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int strncasecmp(const char *s1, const char *s2, size_t len)
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{
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/* Yes, Virginia, it had better be unsigned */
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unsigned char c1, c2;
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if (!len)
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return 0;
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do {
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c1 = *s1++;
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c2 = *s2++;
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if (!c1 || !c2)
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break;
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if (c1 == c2)
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continue;
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c1 = tolower(c1);
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c2 = tolower(c2);
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if (c1 != c2)
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break;
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} while (--len);
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return (int)c1 - (int)c2;
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}
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EXPORT_SYMBOL(strncasecmp);
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#endif
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#ifndef __HAVE_ARCH_STRCASECMP
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int strcasecmp(const char *s1, const char *s2)
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{
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int c1, c2;
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do {
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c1 = tolower(*s1++);
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c2 = tolower(*s2++);
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} while (c1 == c2 && c1 != 0);
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return c1 - c2;
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}
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EXPORT_SYMBOL(strcasecmp);
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#endif
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#ifndef __HAVE_ARCH_STRCPY
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/**
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* strcpy - Copy a %NUL terminated string
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* @dest: Where to copy the string to
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* @src: Where to copy the string from
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*/
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#undef strcpy
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char *strcpy(char *dest, const char *src)
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{
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char *tmp = dest;
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while ((*dest++ = *src++) != '\0')
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/* nothing */;
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return tmp;
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}
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EXPORT_SYMBOL(strcpy);
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#endif
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#ifndef __HAVE_ARCH_STRNCPY
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/**
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* strncpy - Copy a length-limited, C-string
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* @dest: Where to copy the string to
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* @src: Where to copy the string from
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* @count: The maximum number of bytes to copy
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*
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* The result is not %NUL-terminated if the source exceeds
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* @count bytes.
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*
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* In the case where the length of @src is less than that of
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* count, the remainder of @dest will be padded with %NUL.
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*
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*/
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char *strncpy(char *dest, const char *src, size_t count)
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{
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char *tmp = dest;
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while (count) {
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if ((*tmp = *src) != 0)
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src++;
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tmp++;
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count--;
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}
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return dest;
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}
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EXPORT_SYMBOL(strncpy);
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#endif
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#ifndef __HAVE_ARCH_STRLCPY
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/**
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* strlcpy - Copy a C-string into a sized buffer
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* @dest: Where to copy the string to
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* @src: Where to copy the string from
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* @size: size of destination buffer
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*
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* Compatible with ``*BSD``: the result is always a valid
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* NUL-terminated string that fits in the buffer (unless,
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* of course, the buffer size is zero). It does not pad
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* out the result like strncpy() does.
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*/
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size_t strlcpy(char *dest, const char *src, size_t size)
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{
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size_t ret = strlen(src);
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if (size) {
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size_t len = (ret >= size) ? size - 1 : ret;
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memcpy(dest, src, len);
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dest[len] = '\0';
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}
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return ret;
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}
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EXPORT_SYMBOL(strlcpy);
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#endif
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#ifndef __HAVE_ARCH_STRSCPY
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/**
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* strscpy - Copy a C-string into a sized buffer
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* @dest: Where to copy the string to
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* @src: Where to copy the string from
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* @count: Size of destination buffer
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*
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* Copy the string, or as much of it as fits, into the dest buffer.
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* The routine returns the number of characters copied (not including
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* the trailing NUL) or -E2BIG if the destination buffer wasn't big enough.
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* The behavior is undefined if the string buffers overlap.
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* The destination buffer is always NUL terminated, unless it's zero-sized.
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*
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* Preferred to strlcpy() since the API doesn't require reading memory
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* from the src string beyond the specified "count" bytes, and since
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* the return value is easier to error-check than strlcpy()'s.
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* In addition, the implementation is robust to the string changing out
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* from underneath it, unlike the current strlcpy() implementation.
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*
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* Preferred to strncpy() since it always returns a valid string, and
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* doesn't unnecessarily force the tail of the destination buffer to be
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* zeroed. If the zeroing is desired, it's likely cleaner to use strscpy()
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* with an overflow test, then just memset() the tail of the dest buffer.
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*/
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ssize_t strscpy(char *dest, const char *src, size_t count)
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{
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const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
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size_t max = count;
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long res = 0;
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if (count == 0)
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return -E2BIG;
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#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
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/*
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* If src is unaligned, don't cross a page boundary,
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* since we don't know if the next page is mapped.
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*/
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if ((long)src & (sizeof(long) - 1)) {
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size_t limit = PAGE_SIZE - ((long)src & (PAGE_SIZE - 1));
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if (limit < max)
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max = limit;
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}
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#else
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/* If src or dest is unaligned, don't do word-at-a-time. */
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if (((long) dest | (long) src) & (sizeof(long) - 1))
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max = 0;
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#endif
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while (max >= sizeof(unsigned long)) {
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unsigned long c, data;
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c = *(unsigned long *)(src+res);
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if (has_zero(c, &data, &constants)) {
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data = prep_zero_mask(c, data, &constants);
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data = create_zero_mask(data);
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*(unsigned long *)(dest+res) = c & zero_bytemask(data);
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return res + find_zero(data);
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}
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*(unsigned long *)(dest+res) = c;
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res += sizeof(unsigned long);
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count -= sizeof(unsigned long);
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max -= sizeof(unsigned long);
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}
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while (count) {
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char c;
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c = src[res];
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dest[res] = c;
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if (!c)
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return res;
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res++;
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count--;
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}
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/* Hit buffer length without finding a NUL; force NUL-termination. */
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if (res)
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dest[res-1] = '\0';
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return -E2BIG;
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}
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EXPORT_SYMBOL(strscpy);
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#endif
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#ifndef __HAVE_ARCH_STRCAT
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/**
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* strcat - Append one %NUL-terminated string to another
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* @dest: The string to be appended to
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* @src: The string to append to it
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*/
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#undef strcat
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char *strcat(char *dest, const char *src)
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{
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char *tmp = dest;
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while (*dest)
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dest++;
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while ((*dest++ = *src++) != '\0')
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;
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return tmp;
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}
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EXPORT_SYMBOL(strcat);
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#endif
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#ifndef __HAVE_ARCH_STRNCAT
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/**
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* strncat - Append a length-limited, C-string to another
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* @dest: The string to be appended to
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* @src: The string to append to it
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* @count: The maximum numbers of bytes to copy
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*
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* Note that in contrast to strncpy(), strncat() ensures the result is
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* terminated.
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*/
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char *strncat(char *dest, const char *src, size_t count)
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{
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char *tmp = dest;
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if (count) {
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while (*dest)
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dest++;
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while ((*dest++ = *src++) != 0) {
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if (--count == 0) {
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*dest = '\0';
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break;
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}
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}
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}
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return tmp;
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}
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EXPORT_SYMBOL(strncat);
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#endif
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#ifndef __HAVE_ARCH_STRLCAT
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/**
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* strlcat - Append a length-limited, C-string to another
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* @dest: The string to be appended to
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* @src: The string to append to it
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* @count: The size of the destination buffer.
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*/
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size_t strlcat(char *dest, const char *src, size_t count)
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{
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size_t dsize = strlen(dest);
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size_t len = strlen(src);
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size_t res = dsize + len;
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/* This would be a bug */
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BUG_ON(dsize >= count);
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dest += dsize;
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count -= dsize;
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if (len >= count)
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len = count-1;
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memcpy(dest, src, len);
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dest[len] = 0;
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return res;
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}
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EXPORT_SYMBOL(strlcat);
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#endif
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#ifndef __HAVE_ARCH_STRCMP
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/**
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* strcmp - Compare two strings
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* @cs: One string
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* @ct: Another string
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*/
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#undef strcmp
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int strcmp(const char *cs, const char *ct)
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{
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unsigned char c1, c2;
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while (1) {
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c1 = *cs++;
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c2 = *ct++;
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if (c1 != c2)
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return c1 < c2 ? -1 : 1;
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if (!c1)
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break;
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}
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return 0;
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}
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EXPORT_SYMBOL(strcmp);
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#endif
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#ifndef __HAVE_ARCH_STRNCMP
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/**
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* strncmp - Compare two length-limited strings
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* @cs: One string
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* @ct: Another string
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* @count: The maximum number of bytes to compare
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*/
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int strncmp(const char *cs, const char *ct, size_t count)
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{
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unsigned char c1, c2;
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while (count) {
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c1 = *cs++;
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c2 = *ct++;
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if (c1 != c2)
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return c1 < c2 ? -1 : 1;
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if (!c1)
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break;
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count--;
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}
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return 0;
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}
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EXPORT_SYMBOL(strncmp);
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#endif
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#ifndef __HAVE_ARCH_STRCHR
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/**
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* strchr - Find the first occurrence of a character in a string
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* @s: The string to be searched
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* @c: The character to search for
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*/
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char *strchr(const char *s, int c)
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{
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for (; *s != (char)c; ++s)
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if (*s == '\0')
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return NULL;
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return (char *)s;
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}
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EXPORT_SYMBOL(strchr);
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#endif
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#ifndef __HAVE_ARCH_STRCHRNUL
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/**
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* strchrnul - Find and return a character in a string, or end of string
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* @s: The string to be searched
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* @c: The character to search for
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*
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* Returns pointer to first occurrence of 'c' in s. If c is not found, then
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* return a pointer to the null byte at the end of s.
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*/
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char *strchrnul(const char *s, int c)
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{
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while (*s && *s != (char)c)
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s++;
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return (char *)s;
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}
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EXPORT_SYMBOL(strchrnul);
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#endif
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#ifndef __HAVE_ARCH_STRRCHR
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/**
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* strrchr - Find the last occurrence of a character in a string
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* @s: The string to be searched
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* @c: The character to search for
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*/
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char *strrchr(const char *s, int c)
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{
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const char *last = NULL;
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do {
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if (*s == (char)c)
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last = s;
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} while (*s++);
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return (char *)last;
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}
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EXPORT_SYMBOL(strrchr);
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#endif
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#ifndef __HAVE_ARCH_STRNCHR
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/**
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* strnchr - Find a character in a length limited string
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* @s: The string to be searched
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* @count: The number of characters to be searched
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* @c: The character to search for
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*/
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char *strnchr(const char *s, size_t count, int c)
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{
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for (; count-- && *s != '\0'; ++s)
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if (*s == (char)c)
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return (char *)s;
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return NULL;
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}
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EXPORT_SYMBOL(strnchr);
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#endif
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/**
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* skip_spaces - Removes leading whitespace from @str.
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* @str: The string to be stripped.
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*
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* Returns a pointer to the first non-whitespace character in @str.
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*/
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char *skip_spaces(const char *str)
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{
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while (isspace(*str))
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++str;
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return (char *)str;
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}
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EXPORT_SYMBOL(skip_spaces);
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/**
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* strim - Removes leading and trailing whitespace from @s.
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* @s: The string to be stripped.
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*
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* Note that the first trailing whitespace is replaced with a %NUL-terminator
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* in the given string @s. Returns a pointer to the first non-whitespace
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* character in @s.
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*/
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char *strim(char *s)
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{
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size_t size;
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char *end;
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size = strlen(s);
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if (!size)
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return s;
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end = s + size - 1;
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while (end >= s && isspace(*end))
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end--;
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*(end + 1) = '\0';
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return skip_spaces(s);
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}
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EXPORT_SYMBOL(strim);
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#ifndef __HAVE_ARCH_STRLEN
|
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/**
|
|
* strlen - Find the length of a string
|
|
* @s: The string to be sized
|
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*/
|
|
size_t strlen(const char *s)
|
|
{
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|
const char *sc;
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|
|
|
for (sc = s; *sc != '\0'; ++sc)
|
|
/* nothing */;
|
|
return sc - s;
|
|
}
|
|
EXPORT_SYMBOL(strlen);
|
|
#endif
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|
|
|
#ifndef __HAVE_ARCH_STRNLEN
|
|
/**
|
|
* strnlen - Find the length of a length-limited string
|
|
* @s: The string to be sized
|
|
* @count: The maximum number of bytes to search
|
|
*/
|
|
size_t strnlen(const char *s, size_t count)
|
|
{
|
|
const char *sc;
|
|
|
|
for (sc = s; count-- && *sc != '\0'; ++sc)
|
|
/* nothing */;
|
|
return sc - s;
|
|
}
|
|
EXPORT_SYMBOL(strnlen);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_STRSPN
|
|
/**
|
|
* strspn - Calculate the length of the initial substring of @s which only contain letters in @accept
|
|
* @s: The string to be searched
|
|
* @accept: The string to search for
|
|
*/
|
|
size_t strspn(const char *s, const char *accept)
|
|
{
|
|
const char *p;
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|
const char *a;
|
|
size_t count = 0;
|
|
|
|
for (p = s; *p != '\0'; ++p) {
|
|
for (a = accept; *a != '\0'; ++a) {
|
|
if (*p == *a)
|
|
break;
|
|
}
|
|
if (*a == '\0')
|
|
return count;
|
|
++count;
|
|
}
|
|
return count;
|
|
}
|
|
|
|
EXPORT_SYMBOL(strspn);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_STRCSPN
|
|
/**
|
|
* strcspn - Calculate the length of the initial substring of @s which does not contain letters in @reject
|
|
* @s: The string to be searched
|
|
* @reject: The string to avoid
|
|
*/
|
|
size_t strcspn(const char *s, const char *reject)
|
|
{
|
|
const char *p;
|
|
const char *r;
|
|
size_t count = 0;
|
|
|
|
for (p = s; *p != '\0'; ++p) {
|
|
for (r = reject; *r != '\0'; ++r) {
|
|
if (*p == *r)
|
|
return count;
|
|
}
|
|
++count;
|
|
}
|
|
return count;
|
|
}
|
|
EXPORT_SYMBOL(strcspn);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_STRPBRK
|
|
/**
|
|
* strpbrk - Find the first occurrence of a set of characters
|
|
* @cs: The string to be searched
|
|
* @ct: The characters to search for
|
|
*/
|
|
char *strpbrk(const char *cs, const char *ct)
|
|
{
|
|
const char *sc1, *sc2;
|
|
|
|
for (sc1 = cs; *sc1 != '\0'; ++sc1) {
|
|
for (sc2 = ct; *sc2 != '\0'; ++sc2) {
|
|
if (*sc1 == *sc2)
|
|
return (char *)sc1;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(strpbrk);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_STRSEP
|
|
/**
|
|
* strsep - Split a string into tokens
|
|
* @s: The string to be searched
|
|
* @ct: The characters to search for
|
|
*
|
|
* strsep() updates @s to point after the token, ready for the next call.
|
|
*
|
|
* It returns empty tokens, too, behaving exactly like the libc function
|
|
* of that name. In fact, it was stolen from glibc2 and de-fancy-fied.
|
|
* Same semantics, slimmer shape. ;)
|
|
*/
|
|
char *strsep(char **s, const char *ct)
|
|
{
|
|
char *sbegin = *s;
|
|
char *end;
|
|
|
|
if (sbegin == NULL)
|
|
return NULL;
|
|
|
|
end = strpbrk(sbegin, ct);
|
|
if (end)
|
|
*end++ = '\0';
|
|
*s = end;
|
|
return sbegin;
|
|
}
|
|
EXPORT_SYMBOL(strsep);
|
|
#endif
|
|
|
|
/**
|
|
* sysfs_streq - return true if strings are equal, modulo trailing newline
|
|
* @s1: one string
|
|
* @s2: another string
|
|
*
|
|
* This routine returns true iff two strings are equal, treating both
|
|
* NUL and newline-then-NUL as equivalent string terminations. It's
|
|
* geared for use with sysfs input strings, which generally terminate
|
|
* with newlines but are compared against values without newlines.
|
|
*/
|
|
bool sysfs_streq(const char *s1, const char *s2)
|
|
{
|
|
while (*s1 && *s1 == *s2) {
|
|
s1++;
|
|
s2++;
|
|
}
|
|
|
|
if (*s1 == *s2)
|
|
return true;
|
|
if (!*s1 && *s2 == '\n' && !s2[1])
|
|
return true;
|
|
if (*s1 == '\n' && !s1[1] && !*s2)
|
|
return true;
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL(sysfs_streq);
|
|
|
|
/**
|
|
* match_string - matches given string in an array
|
|
* @array: array of strings
|
|
* @n: number of strings in the array or -1 for NULL terminated arrays
|
|
* @string: string to match with
|
|
*
|
|
* Return:
|
|
* index of a @string in the @array if matches, or %-EINVAL otherwise.
|
|
*/
|
|
int match_string(const char * const *array, size_t n, const char *string)
|
|
{
|
|
int index;
|
|
const char *item;
|
|
|
|
for (index = 0; index < n; index++) {
|
|
item = array[index];
|
|
if (!item)
|
|
break;
|
|
if (!strcmp(item, string))
|
|
return index;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
EXPORT_SYMBOL(match_string);
|
|
|
|
/**
|
|
* __sysfs_match_string - matches given string in an array
|
|
* @array: array of strings
|
|
* @n: number of strings in the array or -1 for NULL terminated arrays
|
|
* @str: string to match with
|
|
*
|
|
* Returns index of @str in the @array or -EINVAL, just like match_string().
|
|
* Uses sysfs_streq instead of strcmp for matching.
|
|
*/
|
|
int __sysfs_match_string(const char * const *array, size_t n, const char *str)
|
|
{
|
|
const char *item;
|
|
int index;
|
|
|
|
for (index = 0; index < n; index++) {
|
|
item = array[index];
|
|
if (!item)
|
|
break;
|
|
if (sysfs_streq(item, str))
|
|
return index;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
EXPORT_SYMBOL(__sysfs_match_string);
|
|
|
|
#ifndef __HAVE_ARCH_MEMSET
|
|
/**
|
|
* memset - Fill a region of memory with the given value
|
|
* @s: Pointer to the start of the area.
|
|
* @c: The byte to fill the area with
|
|
* @count: The size of the area.
|
|
*
|
|
* Do not use memset() to access IO space, use memset_io() instead.
|
|
*/
|
|
void *memset(void *s, int c, size_t count)
|
|
{
|
|
char *xs = s;
|
|
|
|
while (count--)
|
|
*xs++ = c;
|
|
return s;
|
|
}
|
|
EXPORT_SYMBOL(memset);
|
|
#endif
|
|
|
|
/**
|
|
* memzero_explicit - Fill a region of memory (e.g. sensitive
|
|
* keying data) with 0s.
|
|
* @s: Pointer to the start of the area.
|
|
* @count: The size of the area.
|
|
*
|
|
* Note: usually using memset() is just fine (!), but in cases
|
|
* where clearing out _local_ data at the end of a scope is
|
|
* necessary, memzero_explicit() should be used instead in
|
|
* order to prevent the compiler from optimising away zeroing.
|
|
*
|
|
* memzero_explicit() doesn't need an arch-specific version as
|
|
* it just invokes the one of memset() implicitly.
|
|
*/
|
|
void memzero_explicit(void *s, size_t count)
|
|
{
|
|
memset(s, 0, count);
|
|
barrier_data(s);
|
|
}
|
|
EXPORT_SYMBOL(memzero_explicit);
|
|
|
|
#ifndef __HAVE_ARCH_MEMSET16
|
|
/**
|
|
* memset16() - Fill a memory area with a uint16_t
|
|
* @s: Pointer to the start of the area.
|
|
* @v: The value to fill the area with
|
|
* @count: The number of values to store
|
|
*
|
|
* Differs from memset() in that it fills with a uint16_t instead
|
|
* of a byte. Remember that @count is the number of uint16_ts to
|
|
* store, not the number of bytes.
|
|
*/
|
|
void *memset16(uint16_t *s, uint16_t v, size_t count)
|
|
{
|
|
uint16_t *xs = s;
|
|
|
|
while (count--)
|
|
*xs++ = v;
|
|
return s;
|
|
}
|
|
EXPORT_SYMBOL(memset16);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_MEMSET32
|
|
/**
|
|
* memset32() - Fill a memory area with a uint32_t
|
|
* @s: Pointer to the start of the area.
|
|
* @v: The value to fill the area with
|
|
* @count: The number of values to store
|
|
*
|
|
* Differs from memset() in that it fills with a uint32_t instead
|
|
* of a byte. Remember that @count is the number of uint32_ts to
|
|
* store, not the number of bytes.
|
|
*/
|
|
void *memset32(uint32_t *s, uint32_t v, size_t count)
|
|
{
|
|
uint32_t *xs = s;
|
|
|
|
while (count--)
|
|
*xs++ = v;
|
|
return s;
|
|
}
|
|
EXPORT_SYMBOL(memset32);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_MEMSET64
|
|
/**
|
|
* memset64() - Fill a memory area with a uint64_t
|
|
* @s: Pointer to the start of the area.
|
|
* @v: The value to fill the area with
|
|
* @count: The number of values to store
|
|
*
|
|
* Differs from memset() in that it fills with a uint64_t instead
|
|
* of a byte. Remember that @count is the number of uint64_ts to
|
|
* store, not the number of bytes.
|
|
*/
|
|
void *memset64(uint64_t *s, uint64_t v, size_t count)
|
|
{
|
|
uint64_t *xs = s;
|
|
|
|
while (count--)
|
|
*xs++ = v;
|
|
return s;
|
|
}
|
|
EXPORT_SYMBOL(memset64);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_MEMCPY
|
|
/**
|
|
* memcpy - Copy one area of memory to another
|
|
* @dest: Where to copy to
|
|
* @src: Where to copy from
|
|
* @count: The size of the area.
|
|
*
|
|
* You should not use this function to access IO space, use memcpy_toio()
|
|
* or memcpy_fromio() instead.
|
|
*/
|
|
void *memcpy(void *dest, const void *src, size_t count)
|
|
{
|
|
char *tmp = dest;
|
|
const char *s = src;
|
|
|
|
while (count--)
|
|
*tmp++ = *s++;
|
|
return dest;
|
|
}
|
|
EXPORT_SYMBOL(memcpy);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_MEMMOVE
|
|
/**
|
|
* memmove - Copy one area of memory to another
|
|
* @dest: Where to copy to
|
|
* @src: Where to copy from
|
|
* @count: The size of the area.
|
|
*
|
|
* Unlike memcpy(), memmove() copes with overlapping areas.
|
|
*/
|
|
void *memmove(void *dest, const void *src, size_t count)
|
|
{
|
|
char *tmp;
|
|
const char *s;
|
|
|
|
if (dest <= src) {
|
|
tmp = dest;
|
|
s = src;
|
|
while (count--)
|
|
*tmp++ = *s++;
|
|
} else {
|
|
tmp = dest;
|
|
tmp += count;
|
|
s = src;
|
|
s += count;
|
|
while (count--)
|
|
*--tmp = *--s;
|
|
}
|
|
return dest;
|
|
}
|
|
EXPORT_SYMBOL(memmove);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_MEMCMP
|
|
/**
|
|
* memcmp - Compare two areas of memory
|
|
* @cs: One area of memory
|
|
* @ct: Another area of memory
|
|
* @count: The size of the area.
|
|
*/
|
|
#undef memcmp
|
|
__visible int memcmp(const void *cs, const void *ct, size_t count)
|
|
{
|
|
const unsigned char *su1, *su2;
|
|
int res = 0;
|
|
|
|
for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
|
|
if ((res = *su1 - *su2) != 0)
|
|
break;
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL(memcmp);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_MEMSCAN
|
|
/**
|
|
* memscan - Find a character in an area of memory.
|
|
* @addr: The memory area
|
|
* @c: The byte to search for
|
|
* @size: The size of the area.
|
|
*
|
|
* returns the address of the first occurrence of @c, or 1 byte past
|
|
* the area if @c is not found
|
|
*/
|
|
void *memscan(void *addr, int c, size_t size)
|
|
{
|
|
unsigned char *p = addr;
|
|
|
|
while (size) {
|
|
if (*p == c)
|
|
return (void *)p;
|
|
p++;
|
|
size--;
|
|
}
|
|
return (void *)p;
|
|
}
|
|
EXPORT_SYMBOL(memscan);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_STRSTR
|
|
/**
|
|
* strstr - Find the first substring in a %NUL terminated string
|
|
* @s1: The string to be searched
|
|
* @s2: The string to search for
|
|
*/
|
|
char *strstr(const char *s1, const char *s2)
|
|
{
|
|
size_t l1, l2;
|
|
|
|
l2 = strlen(s2);
|
|
if (!l2)
|
|
return (char *)s1;
|
|
l1 = strlen(s1);
|
|
while (l1 >= l2) {
|
|
l1--;
|
|
if (!memcmp(s1, s2, l2))
|
|
return (char *)s1;
|
|
s1++;
|
|
}
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(strstr);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_STRNSTR
|
|
/**
|
|
* strnstr - Find the first substring in a length-limited string
|
|
* @s1: The string to be searched
|
|
* @s2: The string to search for
|
|
* @len: the maximum number of characters to search
|
|
*/
|
|
char *strnstr(const char *s1, const char *s2, size_t len)
|
|
{
|
|
size_t l2;
|
|
|
|
l2 = strlen(s2);
|
|
if (!l2)
|
|
return (char *)s1;
|
|
while (len >= l2) {
|
|
len--;
|
|
if (!memcmp(s1, s2, l2))
|
|
return (char *)s1;
|
|
s1++;
|
|
}
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(strnstr);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_MEMCHR
|
|
/**
|
|
* memchr - Find a character in an area of memory.
|
|
* @s: The memory area
|
|
* @c: The byte to search for
|
|
* @n: The size of the area.
|
|
*
|
|
* returns the address of the first occurrence of @c, or %NULL
|
|
* if @c is not found
|
|
*/
|
|
void *memchr(const void *s, int c, size_t n)
|
|
{
|
|
const unsigned char *p = s;
|
|
while (n-- != 0) {
|
|
if ((unsigned char)c == *p++) {
|
|
return (void *)(p - 1);
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(memchr);
|
|
#endif
|
|
|
|
static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes)
|
|
{
|
|
while (bytes) {
|
|
if (*start != value)
|
|
return (void *)start;
|
|
start++;
|
|
bytes--;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* memchr_inv - Find an unmatching character in an area of memory.
|
|
* @start: The memory area
|
|
* @c: Find a character other than c
|
|
* @bytes: The size of the area.
|
|
*
|
|
* returns the address of the first character other than @c, or %NULL
|
|
* if the whole buffer contains just @c.
|
|
*/
|
|
void *memchr_inv(const void *start, int c, size_t bytes)
|
|
{
|
|
u8 value = c;
|
|
u64 value64;
|
|
unsigned int words, prefix;
|
|
|
|
if (bytes <= 16)
|
|
return check_bytes8(start, value, bytes);
|
|
|
|
value64 = value;
|
|
#if defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64
|
|
value64 *= 0x0101010101010101ULL;
|
|
#elif defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER)
|
|
value64 *= 0x01010101;
|
|
value64 |= value64 << 32;
|
|
#else
|
|
value64 |= value64 << 8;
|
|
value64 |= value64 << 16;
|
|
value64 |= value64 << 32;
|
|
#endif
|
|
|
|
prefix = (unsigned long)start % 8;
|
|
if (prefix) {
|
|
u8 *r;
|
|
|
|
prefix = 8 - prefix;
|
|
r = check_bytes8(start, value, prefix);
|
|
if (r)
|
|
return r;
|
|
start += prefix;
|
|
bytes -= prefix;
|
|
}
|
|
|
|
words = bytes / 8;
|
|
|
|
while (words) {
|
|
if (*(u64 *)start != value64)
|
|
return check_bytes8(start, value, 8);
|
|
start += 8;
|
|
words--;
|
|
}
|
|
|
|
return check_bytes8(start, value, bytes % 8);
|
|
}
|
|
EXPORT_SYMBOL(memchr_inv);
|
|
|
|
/**
|
|
* strreplace - Replace all occurrences of character in string.
|
|
* @s: The string to operate on.
|
|
* @old: The character being replaced.
|
|
* @new: The character @old is replaced with.
|
|
*
|
|
* Returns pointer to the nul byte at the end of @s.
|
|
*/
|
|
char *strreplace(char *s, char old, char new)
|
|
{
|
|
for (; *s; ++s)
|
|
if (*s == old)
|
|
*s = new;
|
|
return s;
|
|
}
|
|
EXPORT_SYMBOL(strreplace);
|
|
|
|
void fortify_panic(const char *name)
|
|
{
|
|
pr_emerg("detected buffer overflow in %s\n", name);
|
|
BUG();
|
|
}
|
|
EXPORT_SYMBOL(fortify_panic);
|