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Diffstat (limited to 'include/linux/string.h')
| -rw-r--r-- | include/linux/string.h | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/include/linux/string.h b/include/linux/string.h new file mode 100644 index 000000000..5077776e9 --- /dev/null +++ b/include/linux/string.h @@ -0,0 +1,406 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_STRING_H_ +#define _LINUX_STRING_H_ + +#include <linux/compiler.h> /* for inline */ +#include <linux/types.h> /* for size_t */ +#include <linux/stddef.h> /* for NULL */ +#include <linux/err.h> /* for ERR_PTR() */ +#include <linux/errno.h> /* for E2BIG */ +#include <linux/overflow.h> /* for check_mul_overflow() */ +#include <linux/stdarg.h> +#include <uapi/linux/string.h> + +extern char *strndup_user(const char __user *, long); +extern void *memdup_user(const void __user *, size_t); +extern void *vmemdup_user(const void __user *, size_t); +extern void *memdup_user_nul(const void __user *, size_t); + +/** + * memdup_array_user - duplicate array from user space + * @src: source address in user space + * @n: number of array members to copy + * @size: size of one array member + * + * Return: an ERR_PTR() on failure. Result is physically + * contiguous, to be freed by kfree(). + */ +static inline void *memdup_array_user(const void __user *src, size_t n, size_t size) +{ + size_t nbytes; + + if (check_mul_overflow(n, size, &nbytes)) + return ERR_PTR(-EOVERFLOW); + + return memdup_user(src, nbytes); +} + +/** + * vmemdup_array_user - duplicate array from user space + * @src: source address in user space + * @n: number of array members to copy + * @size: size of one array member + * + * Return: an ERR_PTR() on failure. Result may be not + * physically contiguous. Use kvfree() to free. + */ +static inline void *vmemdup_array_user(const void __user *src, size_t n, size_t size) +{ + size_t nbytes; + + if (check_mul_overflow(n, size, &nbytes)) + return ERR_PTR(-EOVERFLOW); + + return vmemdup_user(src, nbytes); +} + +/* + * Include machine specific inline routines + */ +#include <asm/string.h> + +#ifndef __HAVE_ARCH_STRCPY +extern char * strcpy(char *,const char *); +#endif +#ifndef __HAVE_ARCH_STRNCPY +extern char * strncpy(char *,const char *, __kernel_size_t); +#endif +#ifndef __HAVE_ARCH_STRLCPY +size_t strlcpy(char *, const char *, size_t); +#endif +#ifndef __HAVE_ARCH_STRSCPY +ssize_t strscpy(char *, const char *, size_t); +#endif + +/* Wraps calls to strscpy()/memset(), no arch specific code required */ +ssize_t strscpy_pad(char *dest, const char *src, size_t count); + +#ifndef __HAVE_ARCH_STRCAT +extern char * strcat(char *, const char *); +#endif +#ifndef __HAVE_ARCH_STRNCAT +extern char * strncat(char *, const char *, __kernel_size_t); +#endif +#ifndef __HAVE_ARCH_STRLCAT +extern size_t strlcat(char *, const char *, __kernel_size_t); +#endif +#ifndef __HAVE_ARCH_STRCMP +extern int strcmp(const char *,const char *); +#endif +#ifndef __HAVE_ARCH_STRNCMP +extern int strncmp(const char *,const char *,__kernel_size_t); +#endif +#ifndef __HAVE_ARCH_STRCASECMP +extern int strcasecmp(const char *s1, const char *s2); +#endif +#ifndef __HAVE_ARCH_STRNCASECMP +extern int strncasecmp(const char *s1, const char *s2, size_t n); +#endif +#ifndef __HAVE_ARCH_STRCHR +extern char * strchr(const char *,int); +#endif +#ifndef __HAVE_ARCH_STRCHRNUL +extern char * strchrnul(const char *,int); +#endif +extern char * strnchrnul(const char *, size_t, int); +#ifndef __HAVE_ARCH_STRNCHR +extern char * strnchr(const char *, size_t, int); +#endif +#ifndef __HAVE_ARCH_STRRCHR +extern char * strrchr(const char *,int); +#endif +extern char * __must_check skip_spaces(const char *); + +extern char *strim(char *); + +static inline __must_check char *strstrip(char *str) +{ + return strim(str); +} + +#ifndef __HAVE_ARCH_STRSTR +extern char * strstr(const char *, const char *); +#endif +#ifndef __HAVE_ARCH_STRNSTR +extern char * strnstr(const char *, const char *, size_t); +#endif +#ifndef __HAVE_ARCH_STRLEN +extern __kernel_size_t strlen(const char *); +#endif +#ifndef __HAVE_ARCH_STRNLEN +extern __kernel_size_t strnlen(const char *,__kernel_size_t); +#endif +#ifndef __HAVE_ARCH_STRPBRK +extern char * strpbrk(const char *,const char *); +#endif +#ifndef __HAVE_ARCH_STRSEP +extern char * strsep(char **,const char *); +#endif +#ifndef __HAVE_ARCH_STRSPN +extern __kernel_size_t strspn(const char *,const char *); +#endif +#ifndef __HAVE_ARCH_STRCSPN +extern __kernel_size_t strcspn(const char *,const char *); +#endif + +#ifndef __HAVE_ARCH_MEMSET +extern void * memset(void *,int,__kernel_size_t); +#endif + +#ifndef __HAVE_ARCH_MEMSET16 +extern void *memset16(uint16_t *, uint16_t, __kernel_size_t); +#endif + +#ifndef __HAVE_ARCH_MEMSET32 +extern void *memset32(uint32_t *, uint32_t, __kernel_size_t); +#endif + +#ifndef __HAVE_ARCH_MEMSET64 +extern void *memset64(uint64_t *, uint64_t, __kernel_size_t); +#endif + +static inline void *memset_l(unsigned long *p, unsigned long v, + __kernel_size_t n) +{ + if (BITS_PER_LONG == 32) + return memset32((uint32_t *)p, v, n); + else + return memset64((uint64_t *)p, v, n); +} + +static inline void *memset_p(void **p, void *v, __kernel_size_t n) +{ + if (BITS_PER_LONG == 32) + return memset32((uint32_t *)p, (uintptr_t)v, n); + else + return memset64((uint64_t *)p, (uintptr_t)v, n); +} + +extern void **__memcat_p(void **a, void **b); +#define memcat_p(a, b) ({ \ + BUILD_BUG_ON_MSG(!__same_type(*(a), *(b)), \ + "type mismatch in memcat_p()"); \ + (typeof(*a) *)__memcat_p((void **)(a), (void **)(b)); \ +}) + +#ifndef __HAVE_ARCH_MEMCPY +extern void * memcpy(void *,const void *,__kernel_size_t); +#endif +#ifndef __HAVE_ARCH_MEMMOVE +extern void * memmove(void *,const void *,__kernel_size_t); +#endif +#ifndef __HAVE_ARCH_MEMSCAN +extern void * memscan(void *,int,__kernel_size_t); +#endif +#ifndef __HAVE_ARCH_MEMCMP +extern int memcmp(const void *,const void *,__kernel_size_t); +#endif +#ifndef __HAVE_ARCH_BCMP +extern int bcmp(const void *,const void *,__kernel_size_t); +#endif +#ifndef __HAVE_ARCH_MEMCHR +extern void * memchr(const void *,int,__kernel_size_t); +#endif +#ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE +static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt) +{ + memcpy(dst, src, cnt); +} +#endif + +void *memchr_inv(const void *s, int c, size_t n); +char *strreplace(char *str, char old, char new); + +extern void kfree_const(const void *x); + +extern char *kstrdup(const char *s, gfp_t gfp) __malloc; +extern const char *kstrdup_const(const char *s, gfp_t gfp); +extern char *kstrndup(const char *s, size_t len, gfp_t gfp); +extern void *kmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2); +extern void *kvmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2); +extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp); + +extern char **argv_split(gfp_t gfp, const char *str, int *argcp); +extern void argv_free(char **argv); + +extern bool sysfs_streq(const char *s1, const char *s2); +int match_string(const char * const *array, size_t n, const char *string); +int __sysfs_match_string(const char * const *array, size_t n, const char *s); + +/** + * sysfs_match_string - matches given string in an array + * @_a: array of strings + * @_s: string to match with + * + * Helper for __sysfs_match_string(). Calculates the size of @a automatically. + */ +#define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s) + +#ifdef CONFIG_BINARY_PRINTF +int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args); +int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf); +int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4); +#endif + +extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, + const void *from, size_t available); + +int ptr_to_hashval(const void *ptr, unsigned long *hashval_out); + +/** + * strstarts - does @str start with @prefix? + * @str: string to examine + * @prefix: prefix to look for. + */ +static inline bool strstarts(const char *str, const char *prefix) +{ + return strncmp(str, prefix, strlen(prefix)) == 0; +} + +size_t memweight(const void *ptr, size_t bytes); + +/** + * 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. + */ +static inline void memzero_explicit(void *s, size_t count) +{ + memset(s, 0, count); + barrier_data(s); +} + +/** + * kbasename - return the last part of a pathname. + * + * @path: path to extract the filename from. + */ +static inline const char *kbasename(const char *path) +{ + const char *tail = strrchr(path, '/'); + return tail ? tail + 1 : path; +} + +#if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE) +#include <linux/fortify-string.h> +#endif +#ifndef unsafe_memcpy +#define unsafe_memcpy(dst, src, bytes, justification) \ + memcpy(dst, src, bytes) +#endif + +void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count, + int pad); + +/** + * strtomem_pad - Copy NUL-terminated string to non-NUL-terminated buffer + * + * @dest: Pointer of destination character array (marked as __nonstring) + * @src: Pointer to NUL-terminated string + * @pad: Padding character to fill any remaining bytes of @dest after copy + * + * This is a replacement for strncpy() uses where the destination is not + * a NUL-terminated string, but with bounds checking on the source size, and + * an explicit padding character. If padding is not required, use strtomem(). + * + * Note that the size of @dest is not an argument, as the length of @dest + * must be discoverable by the compiler. + */ +#define strtomem_pad(dest, src, pad) do { \ + const size_t _dest_len = __builtin_object_size(dest, 1); \ + const size_t _src_len = __builtin_object_size(src, 1); \ + \ + BUILD_BUG_ON(!__builtin_constant_p(_dest_len) || \ + _dest_len == (size_t)-1); \ + memcpy_and_pad(dest, _dest_len, src, \ + strnlen(src, min(_src_len, _dest_len)), pad); \ +} while (0) + +/** + * strtomem - Copy NUL-terminated string to non-NUL-terminated buffer + * + * @dest: Pointer of destination character array (marked as __nonstring) + * @src: Pointer to NUL-terminated string + * + * This is a replacement for strncpy() uses where the destination is not + * a NUL-terminated string, but with bounds checking on the source size, and + * without trailing padding. If padding is required, use strtomem_pad(). + * + * Note that the size of @dest is not an argument, as the length of @dest + * must be discoverable by the compiler. + */ +#define strtomem(dest, src) do { \ + const size_t _dest_len = __builtin_object_size(dest, 1); \ + const size_t _src_len = __builtin_object_size(src, 1); \ + \ + BUILD_BUG_ON(!__builtin_constant_p(_dest_len) || \ + _dest_len == (size_t)-1); \ + memcpy(dest, src, strnlen(src, min(_src_len, _dest_len))); \ +} while (0) + +/** + * memset_after - Set a value after a struct member to the end of a struct + * + * @obj: Address of target struct instance + * @v: Byte value to repeatedly write + * @member: after which struct member to start writing bytes + * + * This is good for clearing padding following the given member. + */ +#define memset_after(obj, v, member) \ +({ \ + u8 *__ptr = (u8 *)(obj); \ + typeof(v) __val = (v); \ + memset(__ptr + offsetofend(typeof(*(obj)), member), __val, \ + sizeof(*(obj)) - offsetofend(typeof(*(obj)), member)); \ +}) + +/** + * memset_startat - Set a value starting at a member to the end of a struct + * + * @obj: Address of target struct instance + * @v: Byte value to repeatedly write + * @member: struct member to start writing at + * + * Note that if there is padding between the prior member and the target + * member, memset_after() should be used to clear the prior padding. + */ +#define memset_startat(obj, v, member) \ +({ \ + u8 *__ptr = (u8 *)(obj); \ + typeof(v) __val = (v); \ + memset(__ptr + offsetof(typeof(*(obj)), member), __val, \ + sizeof(*(obj)) - offsetof(typeof(*(obj)), member)); \ +}) + +/** + * str_has_prefix - Test if a string has a given prefix + * @str: The string to test + * @prefix: The string to see if @str starts with + * + * A common way to test a prefix of a string is to do: + * strncmp(str, prefix, sizeof(prefix) - 1) + * + * But this can lead to bugs due to typos, or if prefix is a pointer + * and not a constant. Instead use str_has_prefix(). + * + * Returns: + * * strlen(@prefix) if @str starts with @prefix + * * 0 if @str does not start with @prefix + */ +static __always_inline size_t str_has_prefix(const char *str, const char *prefix) +{ + size_t len = strlen(prefix); + return strncmp(str, prefix, len) == 0 ? len : 0; +} + +#endif /* _LINUX_STRING_H_ */ |