511 lines
13 KiB
C
511 lines
13 KiB
C
/* $Id: uaccess.h,v 1.11 2003/10/13 07:21:20 lethal Exp $
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*
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* User space memory access functions
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*
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* Copyright (C) 1999, 2002 Niibe Yutaka
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* Copyright (C) 2003 Paul Mundt
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*
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* Based on:
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* MIPS implementation version 1.15 by
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* Copyright (C) 1996, 1997, 1998 by Ralf Baechle
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* and i386 version.
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*/
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#ifndef __ASM_SH_UACCESS_H
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#define __ASM_SH_UACCESS_H
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#include <linux/errno.h>
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#include <linux/sched.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 (Data Segment Register?), these macros are misnamed.
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*/
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#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
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#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFFUL)
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#define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
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#define segment_eq(a,b) ((a).seg == (b).seg)
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#define get_ds() (KERNEL_DS)
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#if !defined(CONFIG_MMU)
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/* NOMMU is always true */
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#define __addr_ok(addr) (1)
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static inline mm_segment_t get_fs(void)
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{
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return USER_DS;
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}
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static inline void set_fs(mm_segment_t s)
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{
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}
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/*
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* __access_ok: Check if address with size is OK or not.
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*
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* If we don't have an MMU (or if its disabled) the only thing we really have
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* to look out for is if the address resides somewhere outside of what
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* available RAM we have.
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*
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* TODO: This check could probably also stand to be restricted somewhat more..
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* though it still does the Right Thing(tm) for the time being.
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*/
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static inline int __access_ok(unsigned long addr, unsigned long size)
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{
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return ((addr >= memory_start) && ((addr + size) < memory_end));
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}
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#else /* CONFIG_MMU */
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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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#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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/*
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* __access_ok: Check if address with size is OK or not.
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*
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* Uhhuh, this needs 33-bit arithmetic. We have a carry..
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*
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* sum := addr + size; carry? --> flag = true;
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* if (sum >= addr_limit) flag = true;
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*/
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static inline int __access_ok(unsigned long addr, unsigned long size)
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{
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unsigned long flag, sum;
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__asm__("clrt\n\t"
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"addc %3, %1\n\t"
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"movt %0\n\t"
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"cmp/hi %4, %1\n\t"
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"rotcl %0"
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:"=&r" (flag), "=r" (sum)
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:"1" (addr), "r" (size),
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"r" (current_thread_info()->addr_limit.seg)
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:"t");
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return flag == 0;
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}
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#endif /* CONFIG_MMU */
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#define access_ok(type, addr, size) \
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(__chk_user_ptr(addr), \
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__access_ok((unsigned long __force)(addr), (size)))
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/*
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* Uh, these should become the main single-value transfer routines ...
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* They automatically use the right size if we just have the right
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* pointer type ...
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*
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* As SuperH uses the same address space for kernel and user data, we
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* can just do these as direct assignments.
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*
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* Careful to not
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* (a) re-use the arguments for side effects (sizeof is ok)
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* (b) require any knowledge of processes at this stage
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*/
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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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struct __large_struct { unsigned long buf[100]; };
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#define __m(x) (*(struct __large_struct __user *)(x))
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#define __get_user_size(x,ptr,size,retval) \
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do { \
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retval = 0; \
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switch (size) { \
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case 1: \
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__get_user_asm(x, ptr, retval, "b"); \
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break; \
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case 2: \
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__get_user_asm(x, ptr, retval, "w"); \
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break; \
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case 4: \
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__get_user_asm(x, ptr, retval, "l"); \
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break; \
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default: \
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__get_user_unknown(); \
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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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unsigned long __gu_val; \
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const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
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__chk_user_ptr(ptr); \
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__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
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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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long __gu_err = -EFAULT; \
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unsigned long __gu_val = 0; \
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const __typeof__(*(ptr)) *__gu_addr = (ptr); \
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if (likely(access_ok(VERIFY_READ, __gu_addr, (size)))) \
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__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
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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(x, addr, err, insn) \
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({ \
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__asm__ __volatile__( \
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"1:\n\t" \
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"mov." insn " %2, %1\n\t" \
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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 #0, %1\n\t" \
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"mov.l 4f, %0\n\t" \
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"jmp @%0\n\t" \
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" mov %3, %0\n\t" \
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".balign 4\n" \
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"4: .long 2b\n\t" \
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".previous\n" \
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".section __ex_table,\"a\"\n\t" \
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".long 1b, 3b\n\t" \
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".previous" \
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:"=&r" (err), "=&r" (x) \
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:"m" (__m(addr)), "i" (-EFAULT), "0" (err)); })
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extern void __get_user_unknown(void);
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#define __put_user_size(x,ptr,size,retval) \
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do { \
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retval = 0; \
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switch (size) { \
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case 1: \
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__put_user_asm(x, ptr, retval, "b"); \
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break; \
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case 2: \
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__put_user_asm(x, ptr, retval, "w"); \
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break; \
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case 4: \
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__put_user_asm(x, ptr, retval, "l"); \
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break; \
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case 8: \
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__put_user_u64(x, ptr, retval); \
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break; \
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default: \
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__put_user_unknown(); \
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} \
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} while (0)
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#define __put_user_nocheck(x,ptr,size) \
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({ \
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long __pu_err; \
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__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
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__chk_user_ptr(ptr); \
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__put_user_size((x), __pu_addr, (size), __pu_err); \
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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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long __pu_err = -EFAULT; \
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__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
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if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) \
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__put_user_size((x), __pu_addr, (size), \
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__pu_err); \
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__pu_err; \
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})
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#define __put_user_asm(x, addr, err, insn) \
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({ \
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__asm__ __volatile__( \
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"1:\n\t" \
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"mov." insn " %1, %2\n\t" \
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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.l 4f, %0\n\t" \
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"jmp @%0\n\t" \
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" mov %3, %0\n\t" \
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".balign 4\n" \
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"4: .long 2b\n\t" \
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".previous\n" \
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".section __ex_table,\"a\"\n\t" \
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".long 1b, 3b\n\t" \
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".previous" \
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:"=&r" (err) \
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:"r" (x), "m" (__m(addr)), "i" (-EFAULT), "0" (err) \
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:"memory"); })
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#if defined(CONFIG_CPU_LITTLE_ENDIAN)
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#define __put_user_u64(val,addr,retval) \
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({ \
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__asm__ __volatile__( \
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"1:\n\t" \
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"mov.l %R1,%2\n\t" \
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"mov.l %S1,%T2\n\t" \
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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.l 4f,%0\n\t" \
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"jmp @%0\n\t" \
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" mov %3,%0\n\t" \
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".balign 4\n" \
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"4: .long 2b\n\t" \
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".previous\n" \
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".section __ex_table,\"a\"\n\t" \
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".long 1b, 3b\n\t" \
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".previous" \
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: "=r" (retval) \
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: "r" (val), "m" (__m(addr)), "i" (-EFAULT), "0" (retval) \
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: "memory"); })
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#else
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#define __put_user_u64(val,addr,retval) \
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({ \
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__asm__ __volatile__( \
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"1:\n\t" \
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"mov.l %S1,%2\n\t" \
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"mov.l %R1,%T2\n\t" \
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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.l 4f,%0\n\t" \
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"jmp @%0\n\t" \
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" mov %3,%0\n\t" \
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".balign 4\n" \
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"4: .long 2b\n\t" \
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".previous\n" \
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".section __ex_table,\"a\"\n\t" \
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".long 1b, 3b\n\t" \
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".previous" \
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: "=r" (retval) \
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: "r" (val), "m" (__m(addr)), "i" (-EFAULT), "0" (retval) \
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: "memory"); })
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#endif
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extern void __put_user_unknown(void);
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/* Generic arbitrary sized copy. */
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/* Return the number of bytes NOT copied */
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__kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
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#define copy_to_user(to,from,n) ({ \
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void *__copy_to = (void *) (to); \
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__kernel_size_t __copy_size = (__kernel_size_t) (n); \
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__kernel_size_t __copy_res; \
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if(__copy_size && __access_ok((unsigned long)__copy_to, __copy_size)) { \
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__copy_res = __copy_user(__copy_to, (void *) (from), __copy_size); \
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} else __copy_res = __copy_size; \
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__copy_res; })
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#define copy_from_user(to,from,n) ({ \
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void *__copy_to = (void *) (to); \
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void *__copy_from = (void *) (from); \
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__kernel_size_t __copy_size = (__kernel_size_t) (n); \
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__kernel_size_t __copy_res; \
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if(__copy_size && __access_ok((unsigned long)__copy_from, __copy_size)) { \
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__copy_res = __copy_user(__copy_to, __copy_from, __copy_size); \
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} else __copy_res = __copy_size; \
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__copy_res; })
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static __always_inline unsigned long
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__copy_from_user(void *to, const void __user *from, unsigned long n)
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{
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return __copy_user(to, (__force void *)from, n);
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}
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static __always_inline unsigned long __must_check
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__copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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return __copy_user((__force void *)to, from, 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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/*
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* Clear the area and return remaining number of bytes
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* (on failure. Usually it's 0.)
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*/
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extern __kernel_size_t __clear_user(void *addr, __kernel_size_t size);
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#define clear_user(addr,n) ({ \
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void * __cl_addr = (addr); \
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unsigned long __cl_size = (n); \
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if (__cl_size && __access_ok(((unsigned long)(__cl_addr)), __cl_size)) \
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__cl_size = __clear_user(__cl_addr, __cl_size); \
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__cl_size; })
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static __inline__ int
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__strncpy_from_user(unsigned long __dest, unsigned long __user __src, int __count)
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{
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__kernel_size_t res;
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unsigned long __dummy, _d, _s, _c;
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__asm__ __volatile__(
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"9:\n"
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"mov.b @%2+, %1\n\t"
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"cmp/eq #0, %1\n\t"
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"bt/s 2f\n"
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"1:\n"
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"mov.b %1, @%3\n\t"
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"dt %4\n\t"
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"bf/s 9b\n\t"
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" add #1, %3\n\t"
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"2:\n\t"
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"sub %4, %0\n"
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"3:\n"
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".section .fixup,\"ax\"\n"
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"4:\n\t"
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"mov.l 5f, %1\n\t"
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"jmp @%1\n\t"
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" mov %9, %0\n\t"
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".balign 4\n"
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"5: .long 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 9b,4b\n"
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".previous"
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: "=r" (res), "=&z" (__dummy), "=r" (_s), "=r" (_d), "=r"(_c)
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: "0" (__count), "2" (__src), "3" (__dest), "4" (__count),
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"i" (-EFAULT)
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: "memory", "t");
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return res;
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}
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/**
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* strncpy_from_user: - Copy a NUL terminated string from userspace.
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* @dst: Destination address, in kernel space. This buffer must be at
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* least @count bytes long.
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* @src: Source address, in user space.
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* @count: Maximum number of bytes to copy, including the trailing NUL.
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*
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* Copies a NUL-terminated string from userspace to kernel space.
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*
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* On success, returns the length of the string (not including the trailing
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* NUL).
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*
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* If access to userspace fails, returns -EFAULT (some data may have been
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* copied).
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*
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* If @count is smaller than the length of the string, copies @count bytes
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* and returns @count.
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*/
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#define strncpy_from_user(dest,src,count) ({ \
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unsigned long __sfu_src = (unsigned long) (src); \
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int __sfu_count = (int) (count); \
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long __sfu_res = -EFAULT; \
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if(__access_ok(__sfu_src, __sfu_count)) { \
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__sfu_res = __strncpy_from_user((unsigned long) (dest), __sfu_src, __sfu_count); \
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} __sfu_res; })
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/*
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* Return the size of a string (including the ending 0 even when we have
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* exceeded the maximum string length).
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*/
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static __inline__ long __strnlen_user(const char __user *__s, long __n)
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{
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unsigned long res;
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unsigned long __dummy;
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__asm__ __volatile__(
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"1:\t"
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"mov.b @(%0,%3), %1\n\t"
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"cmp/eq %4, %0\n\t"
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"bt/s 2f\n\t"
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" add #1, %0\n\t"
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"tst %1, %1\n\t"
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"bf 1b\n\t"
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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.l 4f, %1\n\t"
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"jmp @%1\n\t"
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" mov #0, %0\n"
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".balign 4\n"
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"4: .long 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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: "=z" (res), "=&r" (__dummy)
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: "0" (0), "r" (__s), "r" (__n)
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: "t");
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return res;
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}
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/**
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* strnlen_user: - Get the size of a string in user space.
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* @s: The string to measure.
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* @n: The maximum valid length
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*
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* Context: User context only. This function may sleep.
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*
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* Get the size of a NUL-terminated string in user space.
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*
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* Returns the size of the string INCLUDING the terminating NUL.
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* On exception, returns 0.
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* If the string is too long, returns a value greater than @n.
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*/
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static __inline__ long strnlen_user(const char __user *s, long n)
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{
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if (!__addr_ok(s))
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return 0;
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else
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return __strnlen_user(s, n);
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}
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/**
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* strlen_user: - Get the size of a string in user space.
|
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* @str: The string to measure.
|
|
*
|
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* Context: User context only. This function may sleep.
|
|
*
|
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* 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.
|
|
*/
|
|
#define strlen_user(str) strnlen_user(str, ~0UL >> 1)
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|
|
|
/*
|
|
* The exception table consists of pairs of addresses: the first is the
|
|
* address of an instruction that is allowed to fault, and the second is
|
|
* the address at which the program should continue. No registers are
|
|
* modified, so it is entirely up to the continuation code to figure out
|
|
* what to do.
|
|
*
|
|
* All the routines below use bits of fixup code that are out of line
|
|
* with the main instruction path. This means when everything is well,
|
|
* we don't even have to jump over them. Further, they do not intrude
|
|
* on our cache or tlb entries.
|
|
*/
|
|
|
|
struct exception_table_entry
|
|
{
|
|
unsigned long insn, fixup;
|
|
};
|
|
|
|
extern int fixup_exception(struct pt_regs *regs);
|
|
|
|
#endif /* __ASM_SH_UACCESS_H */
|