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Diffstat (limited to 'kernel/arch/um/include/asm/uaccess.h')
| -rw-r--r-- | kernel/arch/um/include/asm/uaccess.h | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/kernel/arch/um/include/asm/uaccess.h b/kernel/arch/um/include/asm/uaccess.h new file mode 100644 index 000000000..3f22fbf7c --- /dev/null +++ b/kernel/arch/um/include/asm/uaccess.h @@ -0,0 +1,178 @@ +/* + * Copyright (C) 2002 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#ifndef __UM_UACCESS_H +#define __UM_UACCESS_H + +/* thread_info has a mm_segment_t in it, so put the definition up here */ +typedef struct { + unsigned long seg; +} mm_segment_t; + +#include <linux/thread_info.h> +#include <linux/errno.h> +#include <asm/processor.h> +#include <asm/elf.h> + +#define VERIFY_READ 0 +#define VERIFY_WRITE 1 + +/* + * The fs value determines whether argument validity checking should be + * performed or not. If get_fs() == USER_DS, checking is performed, with + * get_fs() == KERNEL_DS, checking is bypassed. + * + * For historical reasons, these macros are grossly misnamed. + */ + +#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) + +#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF) +#define USER_DS MAKE_MM_SEG(TASK_SIZE) + +#define get_ds() (KERNEL_DS) +#define get_fs() (current_thread_info()->addr_limit) +#define set_fs(x) (current_thread_info()->addr_limit = (x)) + +#define segment_eq(a, b) ((a).seg == (b).seg) + +#define __under_task_size(addr, size) \ + (((unsigned long) (addr) < TASK_SIZE) && \ + (((unsigned long) (addr) + (size)) < TASK_SIZE)) + +#define __access_ok_vsyscall(type, addr, size) \ + ((type == VERIFY_READ) && \ + ((unsigned long) (addr) >= FIXADDR_USER_START) && \ + ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \ + ((unsigned long) (addr) + (size) >= (unsigned long)(addr))) + +#define __addr_range_nowrap(addr, size) \ + ((unsigned long) (addr) <= ((unsigned long) (addr) + (size))) + +#define access_ok(type, addr, size) \ + (__addr_range_nowrap(addr, size) && \ + (__under_task_size(addr, size) || \ + __access_ok_vsyscall(type, addr, size) || \ + segment_eq(get_fs(), KERNEL_DS))) + +extern int copy_from_user(void *to, const void __user *from, int n); +extern int copy_to_user(void __user *to, const void *from, int n); + +/* + * strncpy_from_user: - Copy a NUL terminated string from userspace. + * @dst: Destination address, in kernel space. This buffer must be at + * least @count bytes long. + * @src: Source address, in user space. + * @count: Maximum number of bytes to copy, including the trailing NUL. + * + * Copies a NUL-terminated string from userspace to kernel space. + * + * On success, returns the length of the string (not including the trailing + * NUL). + * + * If access to userspace fails, returns -EFAULT (some data may have been + * copied). + * + * If @count is smaller than the length of the string, copies @count bytes + * and returns @count. + */ + +extern int strncpy_from_user(char *dst, const char __user *src, int count); + +/* + * __clear_user: - Zero a block of memory in user space, with less checking. + * @to: Destination address, in user space. + * @n: Number of bytes to zero. + * + * Zero a block of memory in user space. Caller must check + * the specified block with access_ok() before calling this function. + * + * Returns number of bytes that could not be cleared. + * On success, this will be zero. + */ +extern int __clear_user(void __user *mem, int len); + +/* + * clear_user: - Zero a block of memory in user space. + * @to: Destination address, in user space. + * @n: Number of bytes to zero. + * + * Zero a block of memory in user space. + * + * Returns number of bytes that could not be cleared. + * On success, this will be zero. + */ +extern int clear_user(void __user *mem, int len); + +/* + * strlen_user: - Get the size of a string in user space. + * @str: The string to measure. + * @n: The maximum valid length + * + * Get the size of a NUL-terminated string in user space. + * + * Returns the size of the string INCLUDING the terminating NUL. + * On exception, returns 0. + * If the string is too long, returns a value greater than @n. + */ +extern int strnlen_user(const void __user *str, int len); + +#define __copy_from_user(to, from, n) copy_from_user(to, from, n) + +#define __copy_to_user(to, from, n) copy_to_user(to, from, n) + +#define __copy_to_user_inatomic __copy_to_user +#define __copy_from_user_inatomic __copy_from_user + +#define __get_user(x, ptr) \ +({ \ + const __typeof__(*(ptr)) __user *__private_ptr = (ptr); \ + __typeof__(x) __private_val; \ + int __private_ret = -EFAULT; \ + (x) = (__typeof__(*(__private_ptr)))0; \ + if (__copy_from_user((__force void *)&__private_val, (__private_ptr),\ + sizeof(*(__private_ptr))) == 0) { \ + (x) = (__typeof__(*(__private_ptr))) __private_val; \ + __private_ret = 0; \ + } \ + __private_ret; \ +}) + +#define get_user(x, ptr) \ +({ \ + const __typeof__((*(ptr))) __user *private_ptr = (ptr); \ + (access_ok(VERIFY_READ, private_ptr, sizeof(*private_ptr)) ? \ + __get_user(x, private_ptr) : ((x) = (__typeof__(*ptr))0, -EFAULT)); \ +}) + +#define __put_user(x, ptr) \ +({ \ + __typeof__(*(ptr)) __user *__private_ptr = ptr; \ + __typeof__(*(__private_ptr)) __private_val; \ + int __private_ret = -EFAULT; \ + __private_val = (__typeof__(*(__private_ptr))) (x); \ + if (__copy_to_user((__private_ptr), &__private_val, \ + sizeof(*(__private_ptr))) == 0) { \ + __private_ret = 0; \ + } \ + __private_ret; \ +}) + +#define put_user(x, ptr) \ +({ \ + __typeof__(*(ptr)) __user *private_ptr = (ptr); \ + (access_ok(VERIFY_WRITE, private_ptr, sizeof(*private_ptr)) ? \ + __put_user(x, private_ptr) : -EFAULT); \ +}) + +#define strlen_user(str) strnlen_user(str, ~0U >> 1) + +struct exception_table_entry +{ + unsigned long insn; + unsigned long fixup; +}; + +#endif |