linux/arch/x86/boot/string.c

// SPDX-License-Identifier: GPL-2.0-only
/* -*- linux-c -*- ------------------------------------------------------- *
 *
 *   Copyright (C) 1991, 1992 Linus Torvalds
 *   Copyright 2007 rPath, Inc. - All Rights Reserved
 *
 * ----------------------------------------------------------------------- */

/*
 * Very basic string functions
 */

#include <linux/types.h>
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/limits.h>
#include <asm/asm.h>
#include "ctype.h"
#include "string.h"

#define KSTRTOX_OVERFLOW …

/*
 * Undef these macros so that the functions that we provide
 * here will have the correct names regardless of how string.h
 * may have chosen to #define them.
 */
#undef memcpy
#undef memset
#undef memcmp

int memcmp(const void *s1, const void *s2, size_t len)
{ … }

/*
 * Clang may lower `memcmp == 0` to `bcmp == 0`.
 */
int bcmp(const void *s1, const void *s2, size_t len)
{ … }

int strcmp(const char *str1, const char *str2)
{ … }

int strncmp(const char *cs, const char *ct, size_t count)
{ … }

size_t strnlen(const char *s, size_t maxlen)
{ … }

unsigned int atou(const char *s)
{ … }

/* Works only for digits and letters, but small and fast */
#define TOLOWER(x) …

static unsigned int simple_guess_base(const char *cp)
{ … }

/**
 * simple_strtoull - convert a string to an unsigned long long
 * @cp: The start of the string
 * @endp: A pointer to the end of the parsed string will be placed here
 * @base: The number base to use
 */
unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
{ … }

long simple_strtol(const char *cp, char **endp, unsigned int base)
{ … }

/**
 * strlen - Find the length of a string
 * @s: The string to be sized
 */
size_t strlen(const char *s)
{ … }

/**
 * 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)
{ … }

/**
 * strchr - Find the first occurrence of the character c in the string s.
 * @s: the string to be searched
 * @c: the character to search for
 */
char *strchr(const char *s, int c)
{ … }

static inline u64 __div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
{ … }

static inline u64 __div_u64(u64 dividend, u32 divisor)
{ … }

static inline char _tolower(const char c)
{ … }

static const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
{ … }

/*
 * Convert non-negative integer string representation in explicitly given radix
 * to an integer.
 * Return number of characters consumed maybe or-ed with overflow bit.
 * If overflow occurs, result integer (incorrect) is still returned.
 *
 * Don't you dare use this function.
 */
static unsigned int _parse_integer(const char *s,
				   unsigned int base,
				   unsigned long long *p)
{ … }

static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
{ … }

/**
 * kstrtoull - convert a string to an unsigned long long
 * @s: The start of the string. The string must be null-terminated, and may also
 *  include a single newline before its terminating null. The first character
 *  may also be a plus sign, but not a minus sign.
 * @base: The number base to use. The maximum supported base is 16. If base is
 *  given as 0, then the base of the string is automatically detected with the
 *  conventional semantics - If it begins with 0x the number will be parsed as a
 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
 * @res: Where to write the result of the conversion on success.
 *
 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
 * Used as a replacement for the obsolete simple_strtoull. Return code must
 * be checked.
 */
int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
{ … }

static int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
{ … }

/**
 * boot_kstrtoul - convert a string to an unsigned long
 * @s: The start of the string. The string must be null-terminated, and may also
 *  include a single newline before its terminating null. The first character
 *  may also be a plus sign, but not a minus sign.
 * @base: The number base to use. The maximum supported base is 16. If base is
 *  given as 0, then the base of the string is automatically detected with the
 *  conventional semantics - If it begins with 0x the number will be parsed as a
 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
 * @res: Where to write the result of the conversion on success.
 *
 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
 * Used as a replacement for the simple_strtoull.
 */
int boot_kstrtoul(const char *s, unsigned int base, unsigned long *res)
{ … }