diff options
Diffstat (limited to 'include/linux/string.h')
| -rw-r--r-- | include/linux/string.h | 287 |
1 files changed, 258 insertions, 29 deletions
diff --git a/include/linux/string.h b/include/linux/string.h index db28802ab0a6..1b564c36d721 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -2,18 +2,63 @@ #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 <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(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 */ @@ -25,15 +70,83 @@ 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 -#ifndef __HAVE_ARCH_STRSCPY -ssize_t strscpy(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; \ +}) -/* Wraps calls to strscpy()/memset(), no arch specific code required */ -ssize_t strscpy_pad(char *dest, const char *src, size_t count); +/** + * 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 *); @@ -169,19 +282,46 @@ static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt) #endif void *memchr_inv(const void *s, int c, size_t n); -char *strreplace(char *s, char old, char new); +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 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 *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); 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); @@ -196,9 +336,8 @@ int __sysfs_match_string(const char * const *array, size_t n, const char *s); #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, @@ -206,16 +345,6 @@ extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, 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); /** @@ -242,6 +371,10 @@ static inline void memzero_explicit(void *s, size_t count) * 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) { @@ -275,11 +408,16 @@ void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count, * 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 _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, _dest_len), pad); \ + memcpy_and_pad(dest, _dest_len, src, \ + strnlen(src, min(_src_len, _dest_len)), pad); \ } while (0) /** @@ -296,11 +434,70 @@ void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count, * must be discoverable by the compiler. */ #define strtomem(dest, src) do { \ - const size_t _dest_len = __builtin_object_size(dest, 1); \ + 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, min(_dest_len, strnlen(src, _dest_len))); \ + 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) /** @@ -359,4 +556,36 @@ static __always_inline size_t str_has_prefix(const char *str, const char *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_ */ |