diff options
Diffstat (limited to 'include/linux/string.h')
| -rw-r--r-- | include/linux/string.h | 480 |
1 files changed, 457 insertions, 23 deletions
diff --git a/include/linux/string.h b/include/linux/string.h index ac889c5ea11b..1b564c36d721 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -1,15 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_STRING_H_ #define _LINUX_STRING_H_ - +#include <linux/args.h> +#include <linux/array_size.h> +#include <linux/cleanup.h> /* for DEFINE_FREE() */ #include <linux/compiler.h> /* for inline */ #include <linux/types.h> /* for size_t */ #include <linux/stddef.h> /* for NULL */ -#include <stdarg.h> +#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 *memdup_user(const void __user *, size_t) __realloc_size(2); +extern void *vmemdup_user(const void __user *, size_t) __realloc_size(2); +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 __realloc_size(2, 3) +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 __realloc_size(2, 3) +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 @@ -22,9 +70,84 @@ extern char * strcpy(char *,const char *); #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 +ssize_t sized_strscpy(char *, const char *, size_t); + +/* + * The 2 argument style can only be used when dst is an array with a + * known size. + */ +#define __strscpy0(dst, src, ...) \ + sized_strscpy(dst, src, sizeof(dst) + __must_be_array(dst) + \ + __must_be_cstr(dst) + __must_be_cstr(src)) +#define __strscpy1(dst, src, size) \ + sized_strscpy(dst, src, size + __must_be_cstr(dst) + __must_be_cstr(src)) + +#define __strscpy_pad0(dst, src, ...) \ + sized_strscpy_pad(dst, src, sizeof(dst) + __must_be_array(dst) + \ + __must_be_cstr(dst) + __must_be_cstr(src)) +#define __strscpy_pad1(dst, src, size) \ + sized_strscpy_pad(dst, src, size + __must_be_cstr(dst) + __must_be_cstr(src)) + +/** + * strscpy - Copy a C-string into a sized buffer + * @dst: Where to copy the string to + * @src: Where to copy the string from + * @...: Size of destination buffer (optional) + * + * Copy the source string @src, or as much of it as fits, into the + * destination @dst buffer. The behavior is undefined if the string + * buffers overlap. The destination @dst buffer is always NUL terminated, + * unless it's zero-sized. + * + * The size argument @... is only required when @dst is not an array, or + * when the copy needs to be smaller than sizeof(@dst). + * + * Preferred to strncpy() since it always returns a valid string, and + * doesn't unnecessarily force the tail of the destination buffer to be + * zero padded. If padding is desired please use strscpy_pad(). + * + * Returns the number of characters copied in @dst (not including the + * trailing %NUL) or -E2BIG if @size is 0 or the copy from @src was + * truncated. + */ +#define strscpy(dst, src, ...) \ + CONCATENATE(__strscpy, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__) + +#define sized_strscpy_pad(dest, src, count) ({ \ + char *__dst = (dest); \ + const char *__src = (src); \ + const size_t __count = (count); \ + ssize_t __wrote; \ + \ + __wrote = sized_strscpy(__dst, __src, __count); \ + if (__wrote >= 0 && __wrote < __count) \ + memset(__dst + __wrote + 1, 0, __count - __wrote - 1); \ + __wrote; \ +}) + +/** + * strscpy_pad() - Copy a C-string into a sized buffer + * @dst: Where to copy the string to + * @src: Where to copy the string from + * @...: Size of destination buffer + * + * Copy the string, or as much of it as fits, into the dest buffer. The + * behavior is undefined if the string buffers overlap. The destination + * buffer is always %NUL terminated, unless it's zero-sized. + * + * If the source string is shorter than the destination buffer, the + * remaining bytes in the buffer will be filled with %NUL bytes. + * + * For full explanation of why you may want to consider using the + * 'strscpy' functions please see the function docstring for strscpy(). + * + * Returns: + * * The number of characters copied (not including the trailing %NULs) + * * -E2BIG if count is 0 or @src was truncated. + */ +#define strscpy_pad(dst, src, ...) \ + CONCATENATE(__strscpy_pad, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__) + #ifndef __HAVE_ARCH_STRCAT extern char * strcat(char *, const char *); #endif @@ -40,9 +163,6 @@ extern int strcmp(const char *,const char *); #ifndef __HAVE_ARCH_STRNCMP extern int strncmp(const char *,const char *,__kernel_size_t); #endif -#ifndef __HAVE_ARCH_STRNICMP -extern int strnicmp(const char *, const char *, __kernel_size_t); -#endif #ifndef __HAVE_ARCH_STRCASECMP extern int strcasecmp(const char *s1, const char *s2); #endif @@ -52,6 +172,10 @@ extern int strncasecmp(const char *s1, const char *s2, size_t n); #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 @@ -95,6 +219,43 @@ extern __kernel_size_t strcspn(const char *,const char *); #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 @@ -107,46 +268,113 @@ extern void * memscan(void *,int,__kernel_size_t); #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); + +/** + * mem_is_zero - Check if an area of memory is all 0's. + * @s: The memory area + * @n: The size of the area + * + * Return: True if the area of memory is all 0's. + */ +static inline bool mem_is_zero(const void *s, size_t n) +{ + return !memchr_inv(s, 0, n); +} -extern char *kstrdup(const char *s, gfp_t gfp); +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); +extern void *kmemdup_noprof(const void *src, size_t len, gfp_t gfp) __realloc_size(2); +#define kmemdup(...) alloc_hooks(kmemdup_noprof(__VA_ARGS__)) + +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 void *kmemdup_array(const void *src, size_t count, size_t element_size, gfp_t gfp) + __realloc_size(2, 3); +/* lib/argv_split.c */ extern char **argv_split(gfp_t gfp, const char *str, int *argcp); extern void argv_free(char **argv); +DEFINE_FREE(argv_free, char **, if (!IS_ERR_OR_NULL(_T)) argv_free(_T)) + +/* lib/cmdline.c */ +extern int get_option(char **str, int *pint); +extern char *get_options(const char *str, int nints, int *ints); +extern unsigned long long memparse(const char *ptr, char **retptr); +extern bool parse_option_str(const char *str, const char *option); +extern char *next_arg(char *args, char **param, char **val); + extern bool sysfs_streq(const char *s1, const char *s2); -extern int strtobool(const char *s, bool *res); +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); +__printf(3, 0) int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args); +__printf(3, 0) int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf); #endif extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, - const void *from, size_t available); + const void *from, size_t available); + +int ptr_to_hashval(const void *ptr, unsigned long *hashval_out); + +size_t memweight(const void *ptr, size_t bytes); /** - * strstarts - does @str start with @prefix? - * @str: string to examine - * @prefix: prefix to look for. + * 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 bool strstarts(const char *str, const char *prefix) +static inline void memzero_explicit(void *s, size_t count) { - return strncmp(str, prefix, strlen(prefix)) == 0; + memset(s, 0, count); + barrier_data(s); } -extern size_t memweight(const void *ptr, size_t bytes); - /** * kbasename - return the last part of a pathname. * * @path: path to extract the filename from. + * + * Returns: + * Pointer to the filename portion inside @path. If no '/' exists, + * returns @path unchanged. */ static inline const char *kbasename(const char *path) { @@ -154,4 +382,210 @@ static inline const char *kbasename(const char *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 = __must_be_byte_array(dest) + \ + __must_be_noncstr(dest) + \ + ARRAY_SIZE(dest); \ + const size_t _src_len = __must_be_cstr(src) + \ + __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 = __must_be_byte_array(dest) + \ + __must_be_noncstr(dest) + \ + ARRAY_SIZE(dest); \ + const size_t _src_len = __must_be_cstr(src) + \ + __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) + +/** + * memtostr - Copy a possibly non-NUL-term string to a NUL-term string + * @dest: Pointer to destination NUL-terminates string + * @src: Pointer to character array (likely marked as __nonstring) + * + * This is a replacement for strncpy() uses where the source is not + * a NUL-terminated string. + * + * Note that sizes of @dest and @src must be known at compile-time. + */ +#define memtostr(dest, src) do { \ + const size_t _dest_len = __must_be_byte_array(dest) + \ + __must_be_cstr(dest) + \ + ARRAY_SIZE(dest); \ + const size_t _src_len = __must_be_noncstr(src) + \ + __builtin_object_size(src, 1); \ + const size_t _src_chars = strnlen(src, _src_len); \ + const size_t _copy_len = min(_dest_len - 1, _src_chars); \ + \ + BUILD_BUG_ON(!__builtin_constant_p(_dest_len) || \ + !__builtin_constant_p(_src_len) || \ + _dest_len == 0 || _dest_len == (size_t)-1 || \ + _src_len == 0 || _src_len == (size_t)-1); \ + memcpy(dest, src, _copy_len); \ + dest[_copy_len] = '\0'; \ +} while (0) + +/** + * memtostr_pad - Copy a possibly non-NUL-term string to a NUL-term string + * with NUL padding in the destination + * @dest: Pointer to destination NUL-terminates string + * @src: Pointer to character array (likely marked as __nonstring) + * + * This is a replacement for strncpy() uses where the source is not + * a NUL-terminated string. + * + * Note that sizes of @dest and @src must be known at compile-time. + */ +#define memtostr_pad(dest, src) do { \ + const size_t _dest_len = __must_be_byte_array(dest) + \ + __must_be_cstr(dest) + \ + ARRAY_SIZE(dest); \ + const size_t _src_len = __must_be_noncstr(src) + \ + __builtin_object_size(src, 1); \ + const size_t _src_chars = strnlen(src, _src_len); \ + const size_t _copy_len = min(_dest_len - 1, _src_chars); \ + \ + BUILD_BUG_ON(!__builtin_constant_p(_dest_len) || \ + !__builtin_constant_p(_src_len) || \ + _dest_len == 0 || _dest_len == (size_t)-1 || \ + _src_len == 0 || _src_len == (size_t)-1); \ + memcpy(dest, src, _copy_len); \ + memset(&dest[_copy_len], 0, _dest_len - _copy_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; +} + +/** + * strstarts - does @str start with @prefix? + * @str: string to examine + * @prefix: prefix to look for. + * + * Returns: + * True if @str begins with @prefix. False in all other cases. + */ +static inline bool strstarts(const char *str, const char *prefix) +{ + return strncmp(str, prefix, strlen(prefix)) == 0; +} + +/** + * strends - Check if a string ends with another string. + * @str: NULL-terminated string to check against @suffix + * @suffix: NULL-terminated string defining the suffix to look for in @str + * + * Returns: + * True if @str ends with @suffix. False in all other cases. + */ +static inline bool __attribute__((nonnull(1, 2))) +strends(const char *str, const char *suffix) +{ + unsigned int str_len = strlen(str), suffix_len = strlen(suffix); + + if (str_len < suffix_len) + return false; + + return !(strcmp(str + str_len - suffix_len, suffix)); +} + #endif /* _LINUX_STRING_H_ */ |