| #ifndef __ASM_GENERIC_UACCESS_H |
| #define __ASM_GENERIC_UACCESS_H |
| |
| /* |
| * User space memory access functions, these should work |
| * on a ny machine that has kernel and user data in the same |
| * address space, e.g. all NOMMU machines. |
| */ |
| #include <linux/sched.h> |
| #include <linux/mm.h> |
| #include <linux/string.h> |
| |
| #include <asm/segment.h> |
| |
| #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) |
| |
| #ifndef KERNEL_DS |
| #define KERNEL_DS MAKE_MM_SEG(~0UL) |
| #endif |
| |
| #ifndef USER_DS |
| #define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) |
| #endif |
| |
| #ifndef get_fs |
| #define get_ds() (KERNEL_DS) |
| #define get_fs() (current_thread_info()->addr_limit) |
| |
| static inline void set_fs(mm_segment_t fs) |
| { |
| current_thread_info()->addr_limit = fs; |
| } |
| #endif |
| |
| #define segment_eq(a, b) ((a).seg == (b).seg) |
| |
| #define VERIFY_READ 0 |
| #define VERIFY_WRITE 1 |
| |
| #define access_ok(type, addr, size) __access_ok((unsigned long)(addr),(size)) |
| |
| /* |
| * The architecture should really override this if possible, at least |
| * doing a check on the get_fs() |
| */ |
| #ifndef __access_ok |
| static inline int __access_ok(unsigned long addr, unsigned long size) |
| { |
| return 1; |
| } |
| #endif |
| |
| /* |
| * The exception table consists of pairs of addresses: the first is the |
| * address of an instruction that is allowed to fault, and the second is |
| * the address at which the program should continue. No registers are |
| * modified, so it is entirely up to the continuation code to figure out |
| * what to do. |
| * |
| * All the routines below use bits of fixup code that are out of line |
| * with the main instruction path. This means when everything is well, |
| * we don't even have to jump over them. Further, they do not intrude |
| * on our cache or tlb entries. |
| */ |
| |
| struct exception_table_entry |
| { |
| unsigned long insn, fixup; |
| }; |
| |
| /* Returns 0 if exception not found and fixup otherwise. */ |
| extern unsigned long search_exception_table(unsigned long); |
| |
| /* |
| * architectures with an MMU should override these two |
| */ |
| #ifndef __copy_from_user |
| static inline __must_check long __copy_from_user(void *to, |
| const void __user * from, unsigned long n) |
| { |
| if (__builtin_constant_p(n)) { |
| switch(n) { |
| case 1: |
| *(u8 *)to = *(u8 __force *)from; |
| return 0; |
| case 2: |
| *(u16 *)to = *(u16 __force *)from; |
| return 0; |
| case 4: |
| *(u32 *)to = *(u32 __force *)from; |
| return 0; |
| #ifdef CONFIG_64BIT |
| case 8: |
| *(u64 *)to = *(u64 __force *)from; |
| return 0; |
| #endif |
| default: |
| break; |
| } |
| } |
| |
| memcpy(to, (const void __force *)from, n); |
| return 0; |
| } |
| #endif |
| |
| #ifndef __copy_to_user |
| static inline __must_check long __copy_to_user(void __user *to, |
| const void *from, unsigned long n) |
| { |
| if (__builtin_constant_p(n)) { |
| switch(n) { |
| case 1: |
| *(u8 __force *)to = *(u8 *)from; |
| return 0; |
| case 2: |
| *(u16 __force *)to = *(u16 *)from; |
| return 0; |
| case 4: |
| *(u32 __force *)to = *(u32 *)from; |
| return 0; |
| #ifdef CONFIG_64BIT |
| case 8: |
| *(u64 __force *)to = *(u64 *)from; |
| return 0; |
| #endif |
| default: |
| break; |
| } |
| } |
| |
| memcpy((void __force *)to, from, n); |
| return 0; |
| } |
| #endif |
| |
| /* |
| * These are the main single-value transfer routines. They automatically |
| * use the right size if we just have the right pointer type. |
| * This version just falls back to copy_{from,to}_user, which should |
| * provide a fast-path for small values. |
| */ |
| #define __put_user(x, ptr) \ |
| ({ \ |
| __typeof__(*(ptr)) __x = (x); \ |
| int __pu_err = -EFAULT; \ |
| __chk_user_ptr(ptr); \ |
| switch (sizeof (*(ptr))) { \ |
| case 1: \ |
| case 2: \ |
| case 4: \ |
| case 8: \ |
| __pu_err = __put_user_fn(sizeof (*(ptr)), \ |
| ptr, &__x); \ |
| break; \ |
| default: \ |
| __put_user_bad(); \ |
| break; \ |
| } \ |
| __pu_err; \ |
| }) |
| |
| #define put_user(x, ptr) \ |
| ({ \ |
| might_sleep(); \ |
| access_ok(VERIFY_WRITE, ptr, sizeof(*ptr)) ? \ |
| __put_user(x, ptr) : \ |
| -EFAULT; \ |
| }) |
| |
| static inline int __put_user_fn(size_t size, void __user *ptr, void *x) |
| { |
| size = __copy_to_user(ptr, x, size); |
| return size ? -EFAULT : size; |
| } |
| |
| extern int __put_user_bad(void) __attribute__((noreturn)); |
| |
| #define __get_user(x, ptr) \ |
| ({ \ |
| int __gu_err = -EFAULT; \ |
| __chk_user_ptr(ptr); \ |
| switch (sizeof(*(ptr))) { \ |
| case 1: { \ |
| unsigned char __x; \ |
| __gu_err = __get_user_fn(sizeof (*(ptr)), \ |
| ptr, &__x); \ |
| (x) = *(__force __typeof__(*(ptr)) *) &__x; \ |
| break; \ |
| }; \ |
| case 2: { \ |
| unsigned short __x; \ |
| __gu_err = __get_user_fn(sizeof (*(ptr)), \ |
| ptr, &__x); \ |
| (x) = *(__force __typeof__(*(ptr)) *) &__x; \ |
| break; \ |
| }; \ |
| case 4: { \ |
| unsigned int __x; \ |
| __gu_err = __get_user_fn(sizeof (*(ptr)), \ |
| ptr, &__x); \ |
| (x) = *(__force __typeof__(*(ptr)) *) &__x; \ |
| break; \ |
| }; \ |
| case 8: { \ |
| unsigned long long __x; \ |
| __gu_err = __get_user_fn(sizeof (*(ptr)), \ |
| ptr, &__x); \ |
| (x) = *(__force __typeof__(*(ptr)) *) &__x; \ |
| break; \ |
| }; \ |
| default: \ |
| __get_user_bad(); \ |
| break; \ |
| } \ |
| __gu_err; \ |
| }) |
| |
| #define get_user(x, ptr) \ |
| ({ \ |
| might_sleep(); \ |
| access_ok(VERIFY_READ, ptr, sizeof(*ptr)) ? \ |
| __get_user(x, ptr) : \ |
| -EFAULT; \ |
| }) |
| |
| static inline int __get_user_fn(size_t size, const void __user *ptr, void *x) |
| { |
| size = __copy_from_user(x, ptr, size); |
| return size ? -EFAULT : size; |
| } |
| |
| extern int __get_user_bad(void) __attribute__((noreturn)); |
| |
| #ifndef __copy_from_user_inatomic |
| #define __copy_from_user_inatomic __copy_from_user |
| #endif |
| |
| #ifndef __copy_to_user_inatomic |
| #define __copy_to_user_inatomic __copy_to_user |
| #endif |
| |
| static inline long copy_from_user(void *to, |
| const void __user * from, unsigned long n) |
| { |
| might_sleep(); |
| if (access_ok(VERIFY_READ, from, n)) |
| return __copy_from_user(to, from, n); |
| else |
| return n; |
| } |
| |
| static inline long copy_to_user(void __user *to, |
| const void *from, unsigned long n) |
| { |
| might_sleep(); |
| if (access_ok(VERIFY_WRITE, to, n)) |
| return __copy_to_user(to, from, n); |
| else |
| return n; |
| } |
| |
| /* |
| * Copy a null terminated string from userspace. |
| */ |
| #ifndef __strncpy_from_user |
| static inline long |
| __strncpy_from_user(char *dst, const char __user *src, long count) |
| { |
| char *tmp; |
| strncpy(dst, (const char __force *)src, count); |
| for (tmp = dst; *tmp && count > 0; tmp++, count--) |
| ; |
| return (tmp - dst); |
| } |
| #endif |
| |
| static inline long |
| strncpy_from_user(char *dst, const char __user *src, long count) |
| { |
| if (!access_ok(VERIFY_READ, src, 1)) |
| return -EFAULT; |
| return __strncpy_from_user(dst, src, count); |
| } |
| |
| /* |
| * Return the size of a string (including the ending 0) |
| * |
| * Return 0 on exception, a value greater than N if too long |
| */ |
| #ifndef strnlen_user |
| static inline long strnlen_user(const char __user *src, long n) |
| { |
| if (!access_ok(VERIFY_READ, src, 1)) |
| return 0; |
| return strlen((void * __force)src) + 1; |
| } |
| #endif |
| |
| static inline long strlen_user(const char __user *src) |
| { |
| return strnlen_user(src, 32767); |
| } |
| |
| /* |
| * Zero Userspace |
| */ |
| #ifndef __clear_user |
| static inline __must_check unsigned long |
| __clear_user(void __user *to, unsigned long n) |
| { |
| memset((void __force *)to, 0, n); |
| return 0; |
| } |
| #endif |
| |
| static inline __must_check unsigned long |
| clear_user(void __user *to, unsigned long n) |
| { |
| might_sleep(); |
| if (!access_ok(VERIFY_WRITE, to, n)) |
| return n; |
| |
| return __clear_user(to, n); |
| } |
| |
| #endif /* __ASM_GENERIC_UACCESS_H */ |