This did result in double clearing of the error return value on success only but should make a meassurable overhead for sigreturn. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
796 lines
22 KiB
C
796 lines
22 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle
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* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
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*/
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#ifndef _ASM_UACCESS_H
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#define _ASM_UACCESS_H
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/thread_info.h>
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#include <asm-generic/uaccess.h>
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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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#ifdef CONFIG_32BIT
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#define __UA_LIMIT 0x80000000UL
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#define __UA_ADDR ".word"
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#define __UA_LA "la"
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#define __UA_ADDU "addu"
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#define __UA_t0 "$8"
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#define __UA_t1 "$9"
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#endif /* CONFIG_32BIT */
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#ifdef CONFIG_64BIT
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#define __UA_LIMIT (- TASK_SIZE)
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#define __UA_ADDR ".dword"
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#define __UA_LA "dla"
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#define __UA_ADDU "daddu"
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#define __UA_t0 "$12"
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#define __UA_t1 "$13"
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#endif /* CONFIG_64BIT */
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/*
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* USER_DS is a bitmask that has the bits set that may not be set in a valid
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* userspace address. Note that we limit 32-bit userspace to 0x7fff8000 but
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* the arithmetic we're doing only works if the limit is a power of two, so
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* we use 0x80000000 here on 32-bit kernels. If a process passes an invalid
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* address in this range it's the process's problem, not ours :-)
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*/
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#define KERNEL_DS ((mm_segment_t) { 0UL })
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#define USER_DS ((mm_segment_t) { __UA_LIMIT })
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#define VERIFY_READ 0
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#define VERIFY_WRITE 1
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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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/*
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* Is a address valid? This does a straighforward calculation rather
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* than tests.
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*
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* Address valid if:
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* - "addr" doesn't have any high-bits set
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* - AND "size" doesn't have any high-bits set
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* - AND "addr+size" doesn't have any high-bits set
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* - OR we are in kernel mode.
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*
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* __ua_size() is a trick to avoid runtime checking of positive constant
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* sizes; for those we already know at compile time that the size is ok.
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*/
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#define __ua_size(size) \
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((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))
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/*
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* access_ok: - Checks if a user space pointer is valid
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* @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
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* %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
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* to write to a block, it is always safe to read from it.
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* @addr: User space pointer to start of block to check
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* @size: Size of block to check
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*
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* Context: User context only. This function may sleep.
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*
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* Checks if a pointer to a block of memory in user space is valid.
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*
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* Returns true (nonzero) if the memory block may be valid, false (zero)
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* if it is definitely invalid.
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*
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* Note that, depending on architecture, this function probably just
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* checks that the pointer is in the user space range - after calling
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* this function, memory access functions may still return -EFAULT.
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*/
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#define __access_mask get_fs().seg
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#define __access_ok(addr, size, mask) \
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(((signed long)((mask) & ((addr) | ((addr) + (size)) | __ua_size(size)))) == 0)
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#define access_ok(type, addr, size) \
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likely(__access_ok((unsigned long)(addr), (size),__access_mask))
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/*
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* put_user: - Write a simple value into user space.
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* @x: Value to copy to user space.
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* @ptr: Destination address, in user space.
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*
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* Context: User context only. This function may sleep.
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*
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* This macro copies a single simple value from kernel space to user
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* space. It supports simple types like char and int, but not larger
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* data types like structures or arrays.
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*
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* @ptr must have pointer-to-simple-variable type, and @x must be assignable
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* to the result of dereferencing @ptr.
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*
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* Returns zero on success, or -EFAULT on error.
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*/
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#define put_user(x,ptr) \
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__put_user_check((x),(ptr),sizeof(*(ptr)))
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/*
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* get_user: - Get a simple variable from user space.
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* @x: Variable to store result.
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* @ptr: Source address, in user space.
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*
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* Context: User context only. This function may sleep.
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*
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* This macro copies a single simple variable from user space to kernel
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* space. It supports simple types like char and int, but not larger
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* data types like structures or arrays.
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*
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* @ptr must have pointer-to-simple-variable type, and the result of
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* dereferencing @ptr must be assignable to @x without a cast.
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*
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* Returns zero on success, or -EFAULT on error.
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* On error, the variable @x is set to zero.
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*/
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#define get_user(x,ptr) \
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__get_user_check((x),(ptr),sizeof(*(ptr)))
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/*
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* __put_user: - Write a simple value into user space, with less checking.
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* @x: Value to copy to user space.
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* @ptr: Destination address, in user space.
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*
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* Context: User context only. This function may sleep.
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*
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* This macro copies a single simple value from kernel space to user
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* space. It supports simple types like char and int, but not larger
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* data types like structures or arrays.
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*
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* @ptr must have pointer-to-simple-variable type, and @x must be assignable
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* to the result of dereferencing @ptr.
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*
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* Caller must check the pointer with access_ok() before calling this
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* function.
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*
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* Returns zero on success, or -EFAULT on error.
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*/
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#define __put_user(x,ptr) \
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__put_user_nocheck((x),(ptr),sizeof(*(ptr)))
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/*
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* __get_user: - Get a simple variable from user space, with less checking.
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* @x: Variable to store result.
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* @ptr: Source address, in user space.
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*
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* Context: User context only. This function may sleep.
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*
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* This macro copies a single simple variable from user space to kernel
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* space. It supports simple types like char and int, but not larger
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* data types like structures or arrays.
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*
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* @ptr must have pointer-to-simple-variable type, and the result of
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* dereferencing @ptr must be assignable to @x without a cast.
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*
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* Caller must check the pointer with access_ok() before calling this
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* function.
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*
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* Returns zero on success, or -EFAULT on error.
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* On error, the variable @x is set to zero.
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*/
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#define __get_user(x,ptr) \
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__get_user_nocheck((x),(ptr),sizeof(*(ptr)))
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struct __large_struct { unsigned long buf[100]; };
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#define __m(x) (*(struct __large_struct __user *)(x))
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/*
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* Yuck. We need two variants, one for 64bit operation and one
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* for 32 bit mode and old iron.
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*/
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#ifdef CONFIG_32BIT
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#define __GET_USER_DW(val, ptr) __get_user_asm_ll32(val, ptr)
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#endif
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#ifdef CONFIG_64BIT
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#define __GET_USER_DW(val, ptr) __get_user_asm(val, "ld", ptr)
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#endif
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extern void __get_user_unknown(void);
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#define __get_user_common(val, size, ptr) \
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do { \
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switch (size) { \
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case 1: __get_user_asm(val, "lb", ptr); break; \
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case 2: __get_user_asm(val, "lh", ptr); break; \
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case 4: __get_user_asm(val, "lw", ptr); break; \
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case 8: __GET_USER_DW(val, ptr); break; \
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default: __get_user_unknown(); break; \
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} \
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} while (0)
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#define __get_user_nocheck(x,ptr,size) \
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({ \
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long __gu_err; \
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\
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__get_user_common((x), size, ptr); \
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__gu_err; \
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})
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#define __get_user_check(x,ptr,size) \
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({ \
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long __gu_err = -EFAULT; \
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const __typeof__(*(ptr)) __user * __gu_ptr = (ptr); \
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\
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if (likely(access_ok(VERIFY_READ, __gu_ptr, size))) \
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__get_user_common((x), size, __gu_ptr); \
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\
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__gu_err; \
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})
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#define __get_user_asm(val, insn, addr) \
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{ \
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long __gu_tmp; \
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\
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__asm__ __volatile__( \
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"1: " insn " %1, %3 \n" \
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"2: \n" \
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" .section .fixup,\"ax\" \n" \
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"3: li %0, %4 \n" \
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" j 2b \n" \
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" .previous \n" \
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" .section __ex_table,\"a\" \n" \
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" "__UA_ADDR "\t1b, 3b \n" \
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" .previous \n" \
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: "=r" (__gu_err), "=r" (__gu_tmp) \
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: "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \
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\
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(val) = (__typeof__(*(addr))) __gu_tmp; \
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}
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/*
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* Get a long long 64 using 32 bit registers.
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*/
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#define __get_user_asm_ll32(val, addr) \
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{ \
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union { \
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unsigned long long l; \
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__typeof__(*(addr)) t; \
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} __gu_tmp; \
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\
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__asm__ __volatile__( \
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"1: lw %1, (%3) \n" \
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"2: lw %D1, 4(%3) \n" \
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"3: .section .fixup,\"ax\" \n" \
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"4: li %0, %4 \n" \
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" move %1, $0 \n" \
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" move %D1, $0 \n" \
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" j 3b \n" \
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" .previous \n" \
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" .section __ex_table,\"a\" \n" \
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" " __UA_ADDR " 1b, 4b \n" \
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" " __UA_ADDR " 2b, 4b \n" \
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" .previous \n" \
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: "=r" (__gu_err), "=&r" (__gu_tmp.l) \
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: "0" (0), "r" (addr), "i" (-EFAULT)); \
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\
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(val) = __gu_tmp.t; \
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}
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/*
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* Yuck. We need two variants, one for 64bit operation and one
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* for 32 bit mode and old iron.
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*/
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#ifdef CONFIG_32BIT
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#define __PUT_USER_DW(ptr) __put_user_asm_ll32(ptr)
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#endif
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#ifdef CONFIG_64BIT
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#define __PUT_USER_DW(ptr) __put_user_asm("sd", ptr)
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#endif
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#define __put_user_nocheck(x,ptr,size) \
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({ \
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__typeof__(*(ptr)) __pu_val; \
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long __pu_err = 0; \
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\
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__pu_val = (x); \
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switch (size) { \
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case 1: __put_user_asm("sb", ptr); break; \
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case 2: __put_user_asm("sh", ptr); break; \
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case 4: __put_user_asm("sw", ptr); break; \
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case 8: __PUT_USER_DW(ptr); break; \
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default: __put_user_unknown(); break; \
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} \
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__pu_err; \
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})
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#define __put_user_check(x,ptr,size) \
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({ \
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__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
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__typeof__(*(ptr)) __pu_val = (x); \
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long __pu_err = -EFAULT; \
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\
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if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) { \
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switch (size) { \
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case 1: __put_user_asm("sb", __pu_addr); break; \
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case 2: __put_user_asm("sh", __pu_addr); break; \
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case 4: __put_user_asm("sw", __pu_addr); break; \
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case 8: __PUT_USER_DW(__pu_addr); break; \
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default: __put_user_unknown(); break; \
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} \
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} \
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__pu_err; \
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})
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#define __put_user_asm(insn, ptr) \
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{ \
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__asm__ __volatile__( \
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"1: " insn " %z2, %3 # __put_user_asm\n" \
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"2: \n" \
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" .section .fixup,\"ax\" \n" \
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"3: li %0, %4 \n" \
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" j 2b \n" \
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" .previous \n" \
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" .section __ex_table,\"a\" \n" \
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" " __UA_ADDR " 1b, 3b \n" \
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" .previous \n" \
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: "=r" (__pu_err) \
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: "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \
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"i" (-EFAULT)); \
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}
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#define __put_user_asm_ll32(ptr) \
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{ \
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__asm__ __volatile__( \
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"1: sw %2, (%3) # __put_user_asm_ll32 \n" \
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"2: sw %D2, 4(%3) \n" \
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"3: \n" \
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" .section .fixup,\"ax\" \n" \
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"4: li %0, %4 \n" \
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" j 3b \n" \
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" .previous \n" \
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" .section __ex_table,\"a\" \n" \
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" " __UA_ADDR " 1b, 4b \n" \
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" " __UA_ADDR " 2b, 4b \n" \
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" .previous" \
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: "=r" (__pu_err) \
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: "0" (0), "r" (__pu_val), "r" (ptr), \
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"i" (-EFAULT)); \
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}
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extern void __put_user_unknown(void);
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/*
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* We're generating jump to subroutines which will be outside the range of
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* jump instructions
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*/
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#ifdef MODULE
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#define __MODULE_JAL(destination) \
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".set\tnoat\n\t" \
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__UA_LA "\t$1, " #destination "\n\t" \
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"jalr\t$1\n\t" \
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".set\tat\n\t"
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#else
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#define __MODULE_JAL(destination) \
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"jal\t" #destination "\n\t"
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#endif
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extern size_t __copy_user(void *__to, const void *__from, size_t __n);
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#define __invoke_copy_to_user(to,from,n) \
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({ \
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register void __user *__cu_to_r __asm__ ("$4"); \
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register const void *__cu_from_r __asm__ ("$5"); \
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register long __cu_len_r __asm__ ("$6"); \
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\
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__cu_to_r = (to); \
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__cu_from_r = (from); \
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__cu_len_r = (n); \
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__asm__ __volatile__( \
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__MODULE_JAL(__copy_user) \
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: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
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: \
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: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
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"memory"); \
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__cu_len_r; \
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})
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/*
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* __copy_to_user: - Copy a block of data into user space, with less checking.
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* @to: Destination address, in user space.
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* @from: Source address, in kernel space.
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* @n: Number of bytes to copy.
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*
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* Context: User context only. This function may sleep.
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*
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* Copy data from kernel space to 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 copied.
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* On success, this will be zero.
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*/
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#define __copy_to_user(to,from,n) \
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({ \
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void __user *__cu_to; \
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const void *__cu_from; \
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long __cu_len; \
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\
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might_sleep(); \
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__cu_to = (to); \
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__cu_from = (from); \
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__cu_len = (n); \
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__cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
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__cu_len; \
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})
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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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/*
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* copy_to_user: - Copy a block of data into user space.
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* @to: Destination address, in user space.
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* @from: Source address, in kernel space.
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* @n: Number of bytes to copy.
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*
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* Context: User context only. This function may sleep.
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*
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* Copy data from kernel space to user space.
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*
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* Returns number of bytes that could not be copied.
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* On success, this will be zero.
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*/
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#define copy_to_user(to,from,n) \
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({ \
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void __user *__cu_to; \
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const void *__cu_from; \
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long __cu_len; \
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\
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might_sleep(); \
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__cu_to = (to); \
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__cu_from = (from); \
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__cu_len = (n); \
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if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) \
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__cu_len = __invoke_copy_to_user(__cu_to, __cu_from, \
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__cu_len); \
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__cu_len; \
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})
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#define __invoke_copy_from_user(to,from,n) \
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({ \
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register void *__cu_to_r __asm__ ("$4"); \
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register const void __user *__cu_from_r __asm__ ("$5"); \
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register long __cu_len_r __asm__ ("$6"); \
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\
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__cu_to_r = (to); \
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__cu_from_r = (from); \
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|
__cu_len_r = (n); \
|
|
__asm__ __volatile__( \
|
|
".set\tnoreorder\n\t" \
|
|
__MODULE_JAL(__copy_user) \
|
|
".set\tnoat\n\t" \
|
|
__UA_ADDU "\t$1, %1, %2\n\t" \
|
|
".set\tat\n\t" \
|
|
".set\treorder" \
|
|
: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
|
|
: \
|
|
: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
|
|
"memory"); \
|
|
__cu_len_r; \
|
|
})
|
|
|
|
/*
|
|
* __copy_from_user: - Copy a block of data from user space, with less checking.
|
|
* @to: Destination address, in kernel space.
|
|
* @from: Source address, in user space.
|
|
* @n: Number of bytes to copy.
|
|
*
|
|
* Context: User context only. This function may sleep.
|
|
*
|
|
* Copy data from user space to kernel space. Caller must check
|
|
* the specified block with access_ok() before calling this function.
|
|
*
|
|
* Returns number of bytes that could not be copied.
|
|
* On success, this will be zero.
|
|
*
|
|
* If some data could not be copied, this function will pad the copied
|
|
* data to the requested size using zero bytes.
|
|
*/
|
|
#define __copy_from_user(to,from,n) \
|
|
({ \
|
|
void *__cu_to; \
|
|
const void __user *__cu_from; \
|
|
long __cu_len; \
|
|
\
|
|
might_sleep(); \
|
|
__cu_to = (to); \
|
|
__cu_from = (from); \
|
|
__cu_len = (n); \
|
|
__cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
|
|
__cu_len); \
|
|
__cu_len; \
|
|
})
|
|
|
|
/*
|
|
* copy_from_user: - Copy a block of data from user space.
|
|
* @to: Destination address, in kernel space.
|
|
* @from: Source address, in user space.
|
|
* @n: Number of bytes to copy.
|
|
*
|
|
* Context: User context only. This function may sleep.
|
|
*
|
|
* Copy data from user space to kernel space.
|
|
*
|
|
* Returns number of bytes that could not be copied.
|
|
* On success, this will be zero.
|
|
*
|
|
* If some data could not be copied, this function will pad the copied
|
|
* data to the requested size using zero bytes.
|
|
*/
|
|
#define copy_from_user(to,from,n) \
|
|
({ \
|
|
void *__cu_to; \
|
|
const void __user *__cu_from; \
|
|
long __cu_len; \
|
|
\
|
|
might_sleep(); \
|
|
__cu_to = (to); \
|
|
__cu_from = (from); \
|
|
__cu_len = (n); \
|
|
if (access_ok(VERIFY_READ, __cu_from, __cu_len)) \
|
|
__cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
|
|
__cu_len); \
|
|
__cu_len; \
|
|
})
|
|
|
|
#define __copy_in_user(to, from, n) __copy_from_user(to, from, n)
|
|
|
|
#define copy_in_user(to,from,n) \
|
|
({ \
|
|
void __user *__cu_to; \
|
|
const void __user *__cu_from; \
|
|
long __cu_len; \
|
|
\
|
|
might_sleep(); \
|
|
__cu_to = (to); \
|
|
__cu_from = (from); \
|
|
__cu_len = (n); \
|
|
if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) && \
|
|
access_ok(VERIFY_WRITE, __cu_to, __cu_len))) \
|
|
__cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
|
|
__cu_len); \
|
|
__cu_len; \
|
|
})
|
|
|
|
/*
|
|
* __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.
|
|
*/
|
|
static inline __kernel_size_t
|
|
__clear_user(void __user *addr, __kernel_size_t size)
|
|
{
|
|
__kernel_size_t res;
|
|
|
|
might_sleep();
|
|
__asm__ __volatile__(
|
|
"move\t$4, %1\n\t"
|
|
"move\t$5, $0\n\t"
|
|
"move\t$6, %2\n\t"
|
|
__MODULE_JAL(__bzero)
|
|
"move\t%0, $6"
|
|
: "=r" (res)
|
|
: "r" (addr), "r" (size)
|
|
: "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
|
|
|
|
return res;
|
|
}
|
|
|
|
#define clear_user(addr,n) \
|
|
({ \
|
|
void __user * __cl_addr = (addr); \
|
|
unsigned long __cl_size = (n); \
|
|
if (__cl_size && access_ok(VERIFY_WRITE, \
|
|
((unsigned long)(__cl_addr)), __cl_size)) \
|
|
__cl_size = __clear_user(__cl_addr, __cl_size); \
|
|
__cl_size; \
|
|
})
|
|
|
|
/*
|
|
* __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
|
|
* @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.
|
|
* Caller must check the specified block with access_ok() before calling
|
|
* this function.
|
|
*
|
|
* 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.
|
|
*/
|
|
static inline long
|
|
__strncpy_from_user(char *__to, const char __user *__from, long __len)
|
|
{
|
|
long res;
|
|
|
|
might_sleep();
|
|
__asm__ __volatile__(
|
|
"move\t$4, %1\n\t"
|
|
"move\t$5, %2\n\t"
|
|
"move\t$6, %3\n\t"
|
|
__MODULE_JAL(__strncpy_from_user_nocheck_asm)
|
|
"move\t%0, $2"
|
|
: "=r" (res)
|
|
: "r" (__to), "r" (__from), "r" (__len)
|
|
: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
|
|
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static inline long
|
|
strncpy_from_user(char *__to, const char __user *__from, long __len)
|
|
{
|
|
long res;
|
|
|
|
might_sleep();
|
|
__asm__ __volatile__(
|
|
"move\t$4, %1\n\t"
|
|
"move\t$5, %2\n\t"
|
|
"move\t$6, %3\n\t"
|
|
__MODULE_JAL(__strncpy_from_user_asm)
|
|
"move\t%0, $2"
|
|
: "=r" (res)
|
|
: "r" (__to), "r" (__from), "r" (__len)
|
|
: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
|
|
|
|
return res;
|
|
}
|
|
|
|
/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
|
|
static inline long __strlen_user(const char __user *s)
|
|
{
|
|
long res;
|
|
|
|
might_sleep();
|
|
__asm__ __volatile__(
|
|
"move\t$4, %1\n\t"
|
|
__MODULE_JAL(__strlen_user_nocheck_asm)
|
|
"move\t%0, $2"
|
|
: "=r" (res)
|
|
: "r" (s)
|
|
: "$2", "$4", __UA_t0, "$31");
|
|
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* strlen_user: - Get the size of a string in user space.
|
|
* @str: The string to measure.
|
|
*
|
|
* Context: User context only. This function may sleep.
|
|
*
|
|
* 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 there is a limit on the length of a valid string, you may wish to
|
|
* consider using strnlen_user() instead.
|
|
*/
|
|
static inline long strlen_user(const char __user *s)
|
|
{
|
|
long res;
|
|
|
|
might_sleep();
|
|
__asm__ __volatile__(
|
|
"move\t$4, %1\n\t"
|
|
__MODULE_JAL(__strlen_user_asm)
|
|
"move\t%0, $2"
|
|
: "=r" (res)
|
|
: "r" (s)
|
|
: "$2", "$4", __UA_t0, "$31");
|
|
|
|
return res;
|
|
}
|
|
|
|
/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
|
|
static inline long __strnlen_user(const char __user *s, long n)
|
|
{
|
|
long res;
|
|
|
|
might_sleep();
|
|
__asm__ __volatile__(
|
|
"move\t$4, %1\n\t"
|
|
"move\t$5, %2\n\t"
|
|
__MODULE_JAL(__strnlen_user_nocheck_asm)
|
|
"move\t%0, $2"
|
|
: "=r" (res)
|
|
: "r" (s), "r" (n)
|
|
: "$2", "$4", "$5", __UA_t0, "$31");
|
|
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* strlen_user: - Get the size of a string in user space.
|
|
* @str: The string to measure.
|
|
*
|
|
* Context: User context only. This function may sleep.
|
|
*
|
|
* 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 there is a limit on the length of a valid string, you may wish to
|
|
* consider using strnlen_user() instead.
|
|
*/
|
|
static inline long strnlen_user(const char __user *s, long n)
|
|
{
|
|
long res;
|
|
|
|
might_sleep();
|
|
__asm__ __volatile__(
|
|
"move\t$4, %1\n\t"
|
|
"move\t$5, %2\n\t"
|
|
__MODULE_JAL(__strnlen_user_asm)
|
|
"move\t%0, $2"
|
|
: "=r" (res)
|
|
: "r" (s), "r" (n)
|
|
: "$2", "$4", "$5", __UA_t0, "$31");
|
|
|
|
return res;
|
|
}
|
|
|
|
struct exception_table_entry
|
|
{
|
|
unsigned long insn;
|
|
unsigned long nextinsn;
|
|
};
|
|
|
|
extern int fixup_exception(struct pt_regs *regs);
|
|
|
|
#endif /* _ASM_UACCESS_H */
|