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https://github.com/torvalds/linux
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54b71fba68
Fix __put_user_asm8() by jumping to the end label (3:) from the exception handler, rather than jumping back to retry the second store instruction (label 2:). Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
490 lines
13 KiB
C
490 lines
13 KiB
C
/* MN10300 userspace access functions
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*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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*/
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#ifndef _ASM_UACCESS_H
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#define _ASM_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/sched.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/errno.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_XDS MAKE_MM_SEG(0xBFFFFFFF)
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#define KERNEL_DS MAKE_MM_SEG(0x9FFFFFFF)
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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 __kernel_ds_p() (current_thread_info()->addr_limit.seg == 0x9FFFFFFF)
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#define segment_eq(a, b) ((a).seg == (b).seg)
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#define __addr_ok(addr) \
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((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
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/*
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* check that a range of addresses falls within the current address limit
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*/
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static inline int ___range_ok(unsigned long addr, unsigned int size)
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{
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int flag = 1, tmp;
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asm(" add %3,%1 \n" /* set C-flag if addr + size > 4Gb */
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" bcs 0f \n"
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" cmp %4,%1 \n" /* jump if addr+size>limit (error) */
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" bhi 0f \n"
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" clr %0 \n" /* mark okay */
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"0: \n"
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: "=r"(flag), "=&r"(tmp)
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: "1"(addr), "ir"(size),
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"r"(current_thread_info()->addr_limit.seg), "0"(flag)
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: "cc"
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);
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return flag;
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}
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#define __range_ok(addr, size) ___range_ok((unsigned long)(addr), (u32)(size))
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#define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
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#define __access_ok(addr, size) (__range_ok((addr), (size)) == 0)
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static inline int verify_area(int type, const void *addr, unsigned long size)
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{
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return access_ok(type, addr, size) ? 0 : -EFAULT;
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}
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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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/* Returns 0 if exception not found and fixup otherwise. */
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extern int fixup_exception(struct pt_regs *regs);
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#define put_user(x, ptr) __put_user_check((x), (ptr), sizeof(*(ptr)))
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#define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr)))
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/*
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* The "__xxx" versions do not do address space checking, useful when
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* doing multiple accesses to the same area (the user has to do the
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* checks by hand with "access_ok()")
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*/
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#define __put_user(x, ptr) __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
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#define __get_user(x, ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
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/*
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* The "xxx_ret" versions return constant specified in third argument, if
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* something bad happens. These macros can be optimized for the
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* case of just returning from the function xxx_ret is used.
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*/
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#define put_user_ret(x, ptr, ret) \
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({ if (put_user((x), (ptr))) return (ret); })
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#define get_user_ret(x, ptr, ret) \
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({ if (get_user((x), (ptr))) return (ret); })
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#define __put_user_ret(x, ptr, ret) \
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({ if (__put_user((x), (ptr))) return (ret); })
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#define __get_user_ret(x, ptr, ret) \
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({ if (__get_user((x), (ptr))) return (ret); })
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struct __large_struct { unsigned long buf[100]; };
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#define __m(x) (*(struct __large_struct *)(x))
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#define __get_user_nocheck(x, ptr, size) \
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({ \
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__typeof(*(ptr)) __gu_val; \
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unsigned long __gu_addr; \
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int __gu_err; \
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__gu_addr = (unsigned long) (ptr); \
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switch (size) { \
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case 1: __get_user_asm("bu"); break; \
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case 2: __get_user_asm("hu"); break; \
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case 4: __get_user_asm("" ); break; \
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default: __get_user_unknown(); break; \
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} \
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x = (__typeof__(*(ptr))) __gu_val; \
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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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__typeof__(*(ptr)) __gu_val; \
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unsigned long __gu_addr; \
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int __gu_err; \
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__gu_addr = (unsigned long) (ptr); \
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if (likely(__access_ok(__gu_addr,size))) { \
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switch (size) { \
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case 1: __get_user_asm("bu"); break; \
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case 2: __get_user_asm("hu"); break; \
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case 4: __get_user_asm("" ); break; \
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default: __get_user_unknown(); break; \
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} \
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} \
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else { \
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__gu_err = -EFAULT; \
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__gu_val = 0; \
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} \
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x = (__typeof__(*(ptr))) __gu_val; \
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__gu_err; \
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})
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#define __get_user_asm(INSN) \
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({ \
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asm volatile( \
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"1:\n" \
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" mov"INSN" %2,%1\n" \
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" mov 0,%0\n" \
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"2:\n" \
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" .section .fixup,\"ax\"\n" \
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"3:\n\t" \
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" mov %3,%0\n" \
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" jmp 2b\n" \
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" .previous\n" \
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" .section __ex_table,\"a\"\n" \
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" .balign 4\n" \
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" .long 1b, 3b\n" \
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" .previous" \
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: "=&r" (__gu_err), "=&r" (__gu_val) \
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: "m" (__m(__gu_addr)), "i" (-EFAULT)); \
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})
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extern int __get_user_unknown(void);
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#define __put_user_nocheck(x, ptr, size) \
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({ \
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union { \
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__typeof__(*(ptr)) val; \
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u32 bits[2]; \
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} __pu_val; \
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unsigned long __pu_addr; \
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int __pu_err; \
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__pu_val.val = (x); \
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__pu_addr = (unsigned long) (ptr); \
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switch (size) { \
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case 1: __put_user_asm("bu"); break; \
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case 2: __put_user_asm("hu"); break; \
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case 4: __put_user_asm("" ); break; \
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case 8: __put_user_asm8(); break; \
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default: __pu_err = __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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union { \
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__typeof__(*(ptr)) val; \
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u32 bits[2]; \
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} __pu_val; \
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unsigned long __pu_addr; \
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int __pu_err; \
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__pu_val.val = (x); \
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__pu_addr = (unsigned long) (ptr); \
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if (likely(__access_ok(__pu_addr, size))) { \
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switch (size) { \
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case 1: __put_user_asm("bu"); break; \
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case 2: __put_user_asm("hu"); break; \
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case 4: __put_user_asm("" ); break; \
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case 8: __put_user_asm8(); break; \
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default: __pu_err = __put_user_unknown(); break; \
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} \
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} \
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else { \
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__pu_err = -EFAULT; \
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} \
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__pu_err; \
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})
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#define __put_user_asm(INSN) \
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({ \
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asm volatile( \
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"1:\n" \
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" mov"INSN" %1,%2\n" \
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" mov 0,%0\n" \
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"2:\n" \
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" .section .fixup,\"ax\"\n" \
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"3:\n" \
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" mov %3,%0\n" \
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" jmp 2b\n" \
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" .previous\n" \
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" .section __ex_table,\"a\"\n" \
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" .balign 4\n" \
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" .long 1b, 3b\n" \
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" .previous" \
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: "=&r" (__pu_err) \
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: "r" (__pu_val.val), "m" (__m(__pu_addr)), \
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"i" (-EFAULT) \
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); \
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})
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#define __put_user_asm8() \
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({ \
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asm volatile( \
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"1: mov %1,%3 \n" \
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"2: mov %2,%4 \n" \
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" mov 0,%0 \n" \
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"3: \n" \
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" .section .fixup,\"ax\" \n" \
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"4: \n" \
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" mov %5,%0 \n" \
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" jmp 3b \n" \
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" .previous \n" \
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" .section __ex_table,\"a\"\n" \
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" .balign 4 \n" \
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" .long 1b, 4b \n" \
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" .long 2b, 4b \n" \
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" .previous \n" \
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: "=&r" (__pu_err) \
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: "r" (__pu_val.bits[0]), "r" (__pu_val.bits[1]), \
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"m" (__m(__pu_addr)), "m" (__m(__pu_addr+4)), \
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"i" (-EFAULT) \
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); \
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})
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extern int __put_user_unknown(void);
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/*
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* Copy To/From Userspace
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*/
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/* Generic arbitrary sized copy. */
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#define __copy_user(to, from, size) \
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do { \
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if (size) { \
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void *__to = to; \
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const void *__from = from; \
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int w; \
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asm volatile( \
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"0: movbu (%0),%3;\n" \
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"1: movbu %3,(%1);\n" \
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" inc %0;\n" \
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" inc %1;\n" \
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" add -1,%2;\n" \
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" bne 0b;\n" \
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"2:\n" \
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" .section .fixup,\"ax\"\n" \
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"3: jmp 2b\n" \
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" .previous\n" \
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" .section __ex_table,\"a\"\n" \
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" .balign 4\n" \
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" .long 0b,3b\n" \
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" .long 1b,3b\n" \
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" .previous\n" \
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: "=a"(__from), "=a"(__to), "=r"(size), "=&r"(w)\
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: "0"(__from), "1"(__to), "2"(size) \
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: "memory"); \
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} \
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} while (0)
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#define __copy_user_zeroing(to, from, size) \
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do { \
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if (size) { \
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void *__to = to; \
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const void *__from = from; \
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int w; \
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asm volatile( \
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"0: movbu (%0),%3;\n" \
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"1: movbu %3,(%1);\n" \
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" inc %0;\n" \
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" inc %1;\n" \
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" add -1,%2;\n" \
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" bne 0b;\n" \
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"2:\n" \
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" .section .fixup,\"ax\"\n" \
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"3:\n" \
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" mov %2,%0\n" \
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" clr %3\n" \
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"4: movbu %3,(%1);\n" \
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" inc %1;\n" \
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" add -1,%2;\n" \
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" bne 4b;\n" \
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" mov %0,%2\n" \
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" jmp 2b\n" \
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" .previous\n" \
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" .section __ex_table,\"a\"\n" \
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" .balign 4\n" \
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" .long 0b,3b\n" \
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" .long 1b,3b\n" \
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" .previous\n" \
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: "=a"(__from), "=a"(__to), "=r"(size), "=&r"(w)\
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: "0"(__from), "1"(__to), "2"(size) \
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: "memory"); \
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} \
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} while (0)
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/* We let the __ versions of copy_from/to_user inline, because they're often
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* used in fast paths and have only a small space overhead.
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*/
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static inline
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unsigned long __generic_copy_from_user_nocheck(void *to, const void *from,
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unsigned long n)
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{
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__copy_user_zeroing(to, from, n);
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return n;
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}
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static inline
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unsigned long __generic_copy_to_user_nocheck(void *to, const void *from,
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unsigned long n)
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{
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__copy_user(to, from, n);
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return n;
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}
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#if 0
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#error don't use - these macros don't increment to & from pointers
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/* Optimize just a little bit when we know the size of the move. */
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#define __constant_copy_user(to, from, size) \
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do { \
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asm volatile( \
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" mov %0,a0;\n" \
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"0: movbu (%1),d3;\n" \
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"1: movbu d3,(%2);\n" \
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" add -1,a0;\n" \
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" bne 0b;\n" \
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"2:;" \
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".section .fixup,\"ax\"\n" \
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"3: jmp 2b\n" \
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".previous\n" \
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".section __ex_table,\"a\"\n" \
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" .balign 4\n" \
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" .long 0b,3b\n" \
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" .long 1b,3b\n" \
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".previous" \
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: \
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: "d"(size), "d"(to), "d"(from) \
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: "d3", "a0"); \
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} while (0)
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/* Optimize just a little bit when we know the size of the move. */
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#define __constant_copy_user_zeroing(to, from, size) \
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do { \
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asm volatile( \
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" mov %0,a0;\n" \
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"0: movbu (%1),d3;\n" \
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"1: movbu d3,(%2);\n" \
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" add -1,a0;\n" \
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" bne 0b;\n" \
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"2:;" \
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".section .fixup,\"ax\"\n" \
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"3: jmp 2b\n" \
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".previous\n" \
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".section __ex_table,\"a\"\n" \
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" .balign 4\n" \
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" .long 0b,3b\n" \
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" .long 1b,3b\n" \
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".previous" \
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: \
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: "d"(size), "d"(to), "d"(from) \
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: "d3", "a0"); \
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} while (0)
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static inline
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unsigned long __constant_copy_to_user(void *to, const void *from,
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unsigned long n)
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{
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if (access_ok(VERIFY_WRITE, to, n))
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__constant_copy_user(to, from, n);
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return n;
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}
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static inline
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unsigned long __constant_copy_from_user(void *to, const void *from,
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unsigned long n)
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{
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if (access_ok(VERIFY_READ, from, n))
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__constant_copy_user_zeroing(to, from, n);
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return n;
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}
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static inline
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unsigned long __constant_copy_to_user_nocheck(void *to, const void *from,
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unsigned long n)
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{
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__constant_copy_user(to, from, n);
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return n;
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}
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static inline
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unsigned long __constant_copy_from_user_nocheck(void *to, const void *from,
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unsigned long n)
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{
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__constant_copy_user_zeroing(to, from, n);
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return n;
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}
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#endif
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extern unsigned long __generic_copy_to_user(void __user *, const void *,
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unsigned long);
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extern unsigned long __generic_copy_from_user(void *, const void __user *,
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unsigned long);
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#define __copy_to_user_inatomic(to, from, n) \
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__generic_copy_to_user_nocheck((to), (from), (n))
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#define __copy_from_user_inatomic(to, from, n) \
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__generic_copy_from_user_nocheck((to), (from), (n))
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#define __copy_to_user(to, from, n) \
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({ \
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might_sleep(); \
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__copy_to_user_inatomic((to), (from), (n)); \
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})
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#define __copy_from_user(to, from, n) \
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({ \
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might_sleep(); \
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__copy_from_user_inatomic((to), (from), (n)); \
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})
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#define copy_to_user(to, from, n) __generic_copy_to_user((to), (from), (n))
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#define copy_from_user(to, from, n) __generic_copy_from_user((to), (from), (n))
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extern long strncpy_from_user(char *dst, const char __user *src, long count);
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extern long __strncpy_from_user(char *dst, const char __user *src, long count);
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extern long strnlen_user(const char __user *str, long n);
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#define strlen_user(str) strnlen_user(str, ~0UL >> 1)
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extern unsigned long clear_user(void __user *mem, unsigned long len);
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extern unsigned long __clear_user(void __user *mem, unsigned long len);
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#endif /* _ASM_UACCESS_H */
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