451 lines
12 KiB
C
451 lines
12 KiB
C
/*
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* arch/arm/include/asm/uaccess.h
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef _ASMARM_UACCESS_H
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#define _ASMARM_UACCESS_H
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/*
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* User space memory access functions
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*/
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#include <linux/string.h>
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#include <linux/thread_info.h>
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#include <asm/errno.h>
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#include <asm/memory.h>
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#include <asm/domain.h>
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#include <asm/system.h>
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#include <asm/unified.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 exception table consists of pairs of addresses: the first is the
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* address of an instruction that is allowed to fault, and the second is
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* the address at which the program should continue. No registers are
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* modified, so it is entirely up to the continuation code to figure out
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* what to do.
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*
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* All the routines below use bits of fixup code that are out of line
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* with the main instruction path. This means when everything is well,
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* we don't even have to jump over them. Further, they do not intrude
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* on our cache or tlb entries.
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*/
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struct exception_table_entry
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{
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unsigned long insn, fixup;
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};
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extern int fixup_exception(struct pt_regs *regs);
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/*
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* These two are intentionally not defined anywhere - if the kernel
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* code generates any references to them, that's a bug.
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*/
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extern int __get_user_bad(void);
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extern int __put_user_bad(void);
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/*
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* Note that this is actually 0x1,0000,0000
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*/
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#define KERNEL_DS 0x00000000
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#define get_ds() (KERNEL_DS)
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#ifdef CONFIG_MMU
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#define USER_DS TASK_SIZE
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#define get_fs() (current_thread_info()->addr_limit)
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static inline void set_fs(mm_segment_t fs)
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{
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current_thread_info()->addr_limit = fs;
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modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
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}
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#define segment_eq(a,b) ((a) == (b))
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#define __addr_ok(addr) ({ \
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unsigned long flag; \
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__asm__("cmp %2, %0; movlo %0, #0" \
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: "=&r" (flag) \
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: "0" (current_thread_info()->addr_limit), "r" (addr) \
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: "cc"); \
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(flag == 0); })
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/* We use 33-bit arithmetic here... */
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#define __range_ok(addr,size) ({ \
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unsigned long flag, roksum; \
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__chk_user_ptr(addr); \
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__asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
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: "=&r" (flag), "=&r" (roksum) \
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: "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
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: "cc"); \
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flag; })
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/*
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* Single-value transfer routines. They automatically use the right
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* size if we just have the right pointer type. Note that the functions
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* which read from user space (*get_*) need to take care not to leak
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* kernel data even if the calling code is buggy and fails to check
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* the return value. This means zeroing out the destination variable
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* or buffer on error. Normally this is done out of line by the
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* fixup code, but there are a few places where it intrudes on the
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* main code path. When we only write to user space, there is no
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* problem.
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*/
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extern int __get_user_1(void *);
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extern int __get_user_2(void *);
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extern int __get_user_4(void *);
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#define __get_user_x(__r2,__p,__e,__s,__i...) \
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__asm__ __volatile__ ( \
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__asmeq("%0", "r0") __asmeq("%1", "r2") \
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"bl __get_user_" #__s \
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: "=&r" (__e), "=r" (__r2) \
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: "0" (__p) \
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: __i, "cc")
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#define get_user(x,p) \
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({ \
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register const typeof(*(p)) __user *__p asm("r0") = (p);\
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register unsigned long __r2 asm("r2"); \
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register int __e asm("r0"); \
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switch (sizeof(*(__p))) { \
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case 1: \
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__get_user_x(__r2, __p, __e, 1, "lr"); \
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break; \
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case 2: \
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__get_user_x(__r2, __p, __e, 2, "r3", "lr"); \
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break; \
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case 4: \
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__get_user_x(__r2, __p, __e, 4, "lr"); \
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break; \
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default: __e = __get_user_bad(); break; \
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} \
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x = (typeof(*(p))) __r2; \
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__e; \
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})
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extern int __put_user_1(void *, unsigned int);
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extern int __put_user_2(void *, unsigned int);
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extern int __put_user_4(void *, unsigned int);
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extern int __put_user_8(void *, unsigned long long);
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#define __put_user_x(__r2,__p,__e,__s) \
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__asm__ __volatile__ ( \
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__asmeq("%0", "r0") __asmeq("%2", "r2") \
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"bl __put_user_" #__s \
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: "=&r" (__e) \
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: "0" (__p), "r" (__r2) \
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: "ip", "lr", "cc")
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#define put_user(x,p) \
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({ \
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register const typeof(*(p)) __r2 asm("r2") = (x); \
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register const typeof(*(p)) __user *__p asm("r0") = (p);\
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register int __e asm("r0"); \
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switch (sizeof(*(__p))) { \
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case 1: \
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__put_user_x(__r2, __p, __e, 1); \
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break; \
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case 2: \
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__put_user_x(__r2, __p, __e, 2); \
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break; \
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case 4: \
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__put_user_x(__r2, __p, __e, 4); \
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break; \
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case 8: \
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__put_user_x(__r2, __p, __e, 8); \
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break; \
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default: __e = __put_user_bad(); break; \
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} \
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__e; \
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})
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#else /* CONFIG_MMU */
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/*
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* uClinux has only one addr space, so has simplified address limits.
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*/
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#define USER_DS KERNEL_DS
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#define segment_eq(a,b) (1)
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#define __addr_ok(addr) (1)
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#define __range_ok(addr,size) (0)
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#define get_fs() (KERNEL_DS)
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static inline void set_fs(mm_segment_t fs)
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{
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}
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#define get_user(x,p) __get_user(x,p)
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#define put_user(x,p) __put_user(x,p)
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#endif /* CONFIG_MMU */
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#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
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/*
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* The "__xxx" versions of the user access functions do not verify the
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* address space - it must have been done previously with a separate
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* "access_ok()" call.
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*
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* The "xxx_error" versions set the third argument to EFAULT if an
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* error occurs, and leave it unchanged on success. Note that these
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* versions are void (ie, don't return a value as such).
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*/
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#define __get_user(x,ptr) \
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({ \
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long __gu_err = 0; \
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__get_user_err((x),(ptr),__gu_err); \
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__gu_err; \
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})
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#define __get_user_error(x,ptr,err) \
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({ \
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__get_user_err((x),(ptr),err); \
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(void) 0; \
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})
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#define __get_user_err(x,ptr,err) \
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do { \
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unsigned long __gu_addr = (unsigned long)(ptr); \
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unsigned long __gu_val; \
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__chk_user_ptr(ptr); \
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switch (sizeof(*(ptr))) { \
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case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \
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case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \
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case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \
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default: (__gu_val) = __get_user_bad(); \
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} \
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(x) = (__typeof__(*(ptr)))__gu_val; \
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} while (0)
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#define __get_user_asm_byte(x,addr,err) \
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__asm__ __volatile__( \
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"1: " T(ldrb) " %1,[%2],#0\n" \
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"2:\n" \
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" .pushsection .fixup,\"ax\"\n" \
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" .align 2\n" \
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"3: mov %0, %3\n" \
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" mov %1, #0\n" \
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" b 2b\n" \
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" .popsection\n" \
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" .pushsection __ex_table,\"a\"\n" \
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" .align 3\n" \
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" .long 1b, 3b\n" \
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" .popsection" \
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: "+r" (err), "=&r" (x) \
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: "r" (addr), "i" (-EFAULT) \
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: "cc")
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#ifndef __ARMEB__
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#define __get_user_asm_half(x,__gu_addr,err) \
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({ \
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unsigned long __b1, __b2; \
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__get_user_asm_byte(__b1, __gu_addr, err); \
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__get_user_asm_byte(__b2, __gu_addr + 1, err); \
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(x) = __b1 | (__b2 << 8); \
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})
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#else
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#define __get_user_asm_half(x,__gu_addr,err) \
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({ \
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unsigned long __b1, __b2; \
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__get_user_asm_byte(__b1, __gu_addr, err); \
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__get_user_asm_byte(__b2, __gu_addr + 1, err); \
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(x) = (__b1 << 8) | __b2; \
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})
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#endif
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#define __get_user_asm_word(x,addr,err) \
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__asm__ __volatile__( \
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"1: " T(ldr) " %1,[%2],#0\n" \
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"2:\n" \
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" .pushsection .fixup,\"ax\"\n" \
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" .align 2\n" \
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"3: mov %0, %3\n" \
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" mov %1, #0\n" \
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" b 2b\n" \
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" .popsection\n" \
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" .pushsection __ex_table,\"a\"\n" \
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" .align 3\n" \
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" .long 1b, 3b\n" \
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" .popsection" \
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: "+r" (err), "=&r" (x) \
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: "r" (addr), "i" (-EFAULT) \
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: "cc")
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#define __put_user(x,ptr) \
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({ \
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long __pu_err = 0; \
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__put_user_err((x),(ptr),__pu_err); \
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__pu_err; \
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})
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#define __put_user_error(x,ptr,err) \
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({ \
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__put_user_err((x),(ptr),err); \
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(void) 0; \
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})
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#define __put_user_err(x,ptr,err) \
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do { \
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unsigned long __pu_addr = (unsigned long)(ptr); \
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__typeof__(*(ptr)) __pu_val = (x); \
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__chk_user_ptr(ptr); \
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switch (sizeof(*(ptr))) { \
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case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \
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case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \
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case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \
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case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \
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default: __put_user_bad(); \
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} \
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} while (0)
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#define __put_user_asm_byte(x,__pu_addr,err) \
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__asm__ __volatile__( \
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"1: " T(strb) " %1,[%2],#0\n" \
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"2:\n" \
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" .pushsection .fixup,\"ax\"\n" \
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" .align 2\n" \
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"3: mov %0, %3\n" \
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" b 2b\n" \
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" .popsection\n" \
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" .pushsection __ex_table,\"a\"\n" \
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" .align 3\n" \
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" .long 1b, 3b\n" \
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" .popsection" \
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: "+r" (err) \
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: "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
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: "cc")
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#ifndef __ARMEB__
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#define __put_user_asm_half(x,__pu_addr,err) \
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({ \
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unsigned long __temp = (unsigned long)(x); \
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__put_user_asm_byte(__temp, __pu_addr, err); \
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__put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
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})
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#else
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#define __put_user_asm_half(x,__pu_addr,err) \
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({ \
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unsigned long __temp = (unsigned long)(x); \
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__put_user_asm_byte(__temp >> 8, __pu_addr, err); \
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__put_user_asm_byte(__temp, __pu_addr + 1, err); \
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})
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#endif
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#define __put_user_asm_word(x,__pu_addr,err) \
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__asm__ __volatile__( \
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"1: " T(str) " %1,[%2],#0\n" \
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"2:\n" \
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" .pushsection .fixup,\"ax\"\n" \
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" .align 2\n" \
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"3: mov %0, %3\n" \
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" b 2b\n" \
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" .popsection\n" \
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" .pushsection __ex_table,\"a\"\n" \
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" .align 3\n" \
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" .long 1b, 3b\n" \
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" .popsection" \
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: "+r" (err) \
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: "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
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: "cc")
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#ifndef __ARMEB__
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#define __reg_oper0 "%R2"
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#define __reg_oper1 "%Q2"
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#else
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#define __reg_oper0 "%Q2"
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#define __reg_oper1 "%R2"
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#endif
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#define __put_user_asm_dword(x,__pu_addr,err) \
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__asm__ __volatile__( \
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ARM( "1: " T(str) " " __reg_oper1 ", [%1], #4\n" ) \
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ARM( "2: " T(str) " " __reg_oper0 ", [%1]\n" ) \
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THUMB( "1: " T(str) " " __reg_oper1 ", [%1]\n" ) \
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THUMB( "2: " T(str) " " __reg_oper0 ", [%1, #4]\n" ) \
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"3:\n" \
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" .pushsection .fixup,\"ax\"\n" \
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" .align 2\n" \
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"4: mov %0, %3\n" \
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" b 3b\n" \
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" .popsection\n" \
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" .pushsection __ex_table,\"a\"\n" \
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" .align 3\n" \
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" .long 1b, 4b\n" \
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" .long 2b, 4b\n" \
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" .popsection" \
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: "+r" (err), "+r" (__pu_addr) \
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: "r" (x), "i" (-EFAULT) \
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: "cc")
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#ifdef CONFIG_MMU
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extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
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extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
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extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
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extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
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extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
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#else
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#define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0)
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#define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0)
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#define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0)
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#endif
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extern unsigned long __must_check __strncpy_from_user(char *to, const char __user *from, unsigned long count);
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extern unsigned long __must_check __strnlen_user(const char __user *s, long n);
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static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
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{
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if (access_ok(VERIFY_READ, from, n))
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n = __copy_from_user(to, from, n);
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else /* security hole - plug it */
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memset(to, 0, n);
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return n;
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}
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static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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if (access_ok(VERIFY_WRITE, to, n))
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n = __copy_to_user(to, from, n);
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return n;
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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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static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
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{
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if (access_ok(VERIFY_WRITE, to, n))
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n = __clear_user(to, n);
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return n;
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}
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static inline long __must_check strncpy_from_user(char *dst, const char __user *src, long count)
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{
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long res = -EFAULT;
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if (access_ok(VERIFY_READ, src, 1))
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res = __strncpy_from_user(dst, src, count);
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return res;
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}
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#define strlen_user(s) strnlen_user(s, ~0UL >> 1)
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static inline long __must_check strnlen_user(const char __user *s, long n)
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{
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unsigned long res = 0;
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if (__addr_ok(s))
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res = __strnlen_user(s, n);
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return res;
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}
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#endif /* _ASMARM_UACCESS_H */
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