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