459 lines
13 KiB
C
459 lines
13 KiB
C
#ifndef __X86_64_UACCESS_H
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#define __X86_64_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/compiler.h>
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#include <linux/errno.h>
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#include <linux/prefetch.h>
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#include <asm/page.h>
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#define VERIFY_READ 0
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#define VERIFY_WRITE 1
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/*
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* The fs value determines whether argument validity checking should be
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* performed or not. If get_fs() == USER_DS, checking is performed, with
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* get_fs() == KERNEL_DS, checking is bypassed.
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*
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* For historical reasons, these macros are grossly misnamed.
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*/
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#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
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#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFFFFFFFFFFUL)
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#define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
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#define get_ds() (KERNEL_DS)
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#define get_fs() (current_thread_info()->addr_limit)
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#define set_fs(x) (current_thread_info()->addr_limit = (x))
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#define segment_eq(a, b) ((a).seg == (b).seg)
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#define __addr_ok(addr) (!((unsigned long)(addr) & \
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(current_thread_info()->addr_limit.seg)))
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/*
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* Uhhuh, this needs 65-bit arithmetic. We have a carry..
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*/
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#define __range_not_ok(addr, size) \
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({ \
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unsigned long flag, roksum; \
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__chk_user_ptr(addr); \
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asm("# range_ok\n\r" \
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"addq %3,%1 ; sbbq %0,%0 ; cmpq %1,%4 ; sbbq $0,%0" \
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: "=&r" (flag), "=r" (roksum) \
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: "1" (addr), "g" ((long)(size)), \
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"g" (current_thread_info()->addr_limit.seg)); \
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flag; \
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})
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#define access_ok(type, addr, size) (__range_not_ok(addr, size) == 0)
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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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unsigned long insn, fixup;
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};
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extern int fixup_exception(struct pt_regs *regs);
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#define ARCH_HAS_SEARCH_EXTABLE
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/*
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* These are the main single-value transfer routines. They automatically
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* use the right size if we just have the right pointer type.
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*
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* This gets kind of ugly. We want to return _two_ values in "get_user()"
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* and yet we don't want to do any pointers, because that is too much
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* of a performance impact. Thus we have a few rather ugly macros here,
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* and hide all the ugliness from the user.
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*
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* The "__xxx" versions of the user access functions are versions that
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* do not verify the address space, that must have been done previously
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* with a separate "access_ok()" call (this is used when we do multiple
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* accesses to the same area of user memory).
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*/
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#define __get_user_x(size, ret, x, ptr) \
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asm volatile("call __get_user_" #size \
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: "=a" (ret),"=d" (x) \
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: "c" (ptr) \
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: "r8")
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/* Careful: we have to cast the result to the type of the pointer
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* for sign reasons */
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#define get_user(x, ptr) \
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({ \
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unsigned long __val_gu; \
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int __ret_gu; \
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__chk_user_ptr(ptr); \
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switch (sizeof(*(ptr))) { \
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case 1: \
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__get_user_x(1, __ret_gu, __val_gu, ptr); \
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break; \
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case 2: \
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__get_user_x(2, __ret_gu, __val_gu, ptr); \
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break; \
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case 4: \
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__get_user_x(4, __ret_gu, __val_gu, ptr); \
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break; \
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case 8: \
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__get_user_x(8, __ret_gu, __val_gu, ptr); \
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break; \
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default: \
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__get_user_bad(); \
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break; \
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} \
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(x) = (__force typeof(*(ptr)))__val_gu; \
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__ret_gu; \
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})
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extern void __put_user_1(void);
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extern void __put_user_2(void);
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extern void __put_user_4(void);
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extern void __put_user_8(void);
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extern void __put_user_bad(void);
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#define __put_user_x(size, ret, x, ptr) \
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asm volatile("call __put_user_" #size \
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:"=a" (ret) \
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:"c" (ptr),"d" (x) \
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:"r8")
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#define put_user(x, ptr) \
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__put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
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#define __get_user(x, ptr) \
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__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
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#define __put_user(x, ptr) \
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__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
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#define __get_user_unaligned __get_user
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#define __put_user_unaligned __put_user
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#define __put_user_nocheck(x, ptr, size) \
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({ \
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int __pu_err; \
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__put_user_size((x), (ptr), (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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int __pu_err; \
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typeof(*(ptr)) __user *__pu_addr = (ptr); \
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switch (size) { \
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case 1: \
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__put_user_x(1, __pu_err, x, __pu_addr); \
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break; \
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case 2: \
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__put_user_x(2, __pu_err, x, __pu_addr); \
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break; \
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case 4: \
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__put_user_x(4, __pu_err, x, __pu_addr); \
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break; \
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case 8: \
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__put_user_x(8, __pu_err, x, __pu_addr); \
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break; \
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default: \
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__put_user_bad(); \
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} \
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__pu_err; \
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})
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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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__chk_user_ptr(ptr); \
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switch (size) { \
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case 1: \
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__put_user_asm(x, ptr, retval, "b", "b", "iq", -EFAULT);\
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break; \
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case 2: \
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__put_user_asm(x, ptr, retval, "w", "w", "ir", -EFAULT);\
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break; \
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case 4: \
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__put_user_asm(x, ptr, retval, "l", "k", "ir", -EFAULT);\
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break; \
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case 8: \
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__put_user_asm(x, ptr, retval, "q", "", "Zr", -EFAULT); \
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break; \
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default: \
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__put_user_bad(); \
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} \
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} while (0)
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/* FIXME: this hack is definitely wrong -AK */
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struct __large_struct { unsigned long buf[100]; };
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#define __m(x) (*(struct __large_struct __user *)(x))
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/*
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* Tell gcc we read from memory instead of writing: this is because
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* we do not write to any memory gcc knows about, so there are no
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* aliasing issues.
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*/
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#define __put_user_asm(x, addr, err, itype, rtype, ltype, errno) \
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asm volatile("1: mov"itype" %"rtype"1,%2\n" \
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"2:\n" \
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".section .fixup, \"ax\"\n" \
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"3: mov %3,%0\n" \
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" jmp 2b\n" \
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".previous\n" \
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_ASM_EXTABLE(1b, 3b) \
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: "=r"(err) \
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: ltype (x), "m" (__m(addr)), "i" (errno), "0" (err))
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#define __get_user_nocheck(x, ptr, size) \
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({ \
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int __gu_err; \
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unsigned long __gu_val; \
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__get_user_size(__gu_val, (ptr), (size), __gu_err); \
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(x) = (__force typeof(*(ptr)))__gu_val; \
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__gu_err; \
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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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extern int __get_user_8(void);
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extern int __get_user_bad(void);
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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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__chk_user_ptr(ptr); \
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switch (size) { \
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case 1: \
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__get_user_asm(x, ptr, retval, "b", "b", "=q", -EFAULT);\
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break; \
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case 2: \
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__get_user_asm(x, ptr, retval, "w", "w", "=r", -EFAULT);\
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break; \
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case 4: \
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__get_user_asm(x, ptr, retval, "l", "k", "=r", -EFAULT);\
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break; \
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case 8: \
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__get_user_asm(x, ptr, retval, "q", "", "=r", -EFAULT); \
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break; \
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default: \
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(x) = __get_user_bad(); \
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} \
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} while (0)
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#define __get_user_asm(x, addr, err, itype, rtype, ltype, errno) \
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asm volatile("1: mov"itype" %2,%"rtype"1\n" \
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"2:\n" \
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".section .fixup, \"ax\"\n" \
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"3: mov %3,%0\n" \
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" xor"itype" %"rtype"1,%"rtype"1\n" \
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" jmp 2b\n" \
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".previous\n" \
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_ASM_EXTABLE(1b, 3b) \
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: "=r" (err), ltype (x) \
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: "m" (__m(addr)), "i"(errno), "0"(err))
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/*
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* Copy To/From Userspace
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*/
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/* Handles exceptions in both to and from, but doesn't do access_ok */
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__must_check unsigned long
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copy_user_generic(void *to, const void *from, unsigned len);
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__must_check unsigned long
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copy_to_user(void __user *to, const void *from, unsigned len);
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__must_check unsigned long
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copy_from_user(void *to, const void __user *from, unsigned len);
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__must_check unsigned long
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copy_in_user(void __user *to, const void __user *from, unsigned len);
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static __always_inline __must_check
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int __copy_from_user(void *dst, const void __user *src, unsigned size)
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{
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int ret = 0;
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if (!__builtin_constant_p(size))
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return copy_user_generic(dst, (__force void *)src, size);
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switch (size) {
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case 1:__get_user_asm(*(u8 *)dst, (u8 __user *)src,
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ret, "b", "b", "=q", 1);
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return ret;
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case 2:__get_user_asm(*(u16 *)dst, (u16 __user *)src,
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ret, "w", "w", "=r", 2);
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return ret;
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case 4:__get_user_asm(*(u32 *)dst, (u32 __user *)src,
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ret, "l", "k", "=r", 4);
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return ret;
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case 8:__get_user_asm(*(u64 *)dst, (u64 __user *)src,
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ret, "q", "", "=r", 8);
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return ret;
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case 10:
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__get_user_asm(*(u64 *)dst, (u64 __user *)src,
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ret, "q", "", "=r", 16);
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if (unlikely(ret))
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return ret;
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__get_user_asm(*(u16 *)(8 + (char *)dst),
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(u16 __user *)(8 + (char __user *)src),
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ret, "w", "w", "=r", 2);
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return ret;
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case 16:
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__get_user_asm(*(u64 *)dst, (u64 __user *)src,
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ret, "q", "", "=r", 16);
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if (unlikely(ret))
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return ret;
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__get_user_asm(*(u64 *)(8 + (char *)dst),
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(u64 __user *)(8 + (char __user *)src),
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ret, "q", "", "=r", 8);
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return ret;
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default:
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return copy_user_generic(dst, (__force void *)src, size);
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}
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}
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static __always_inline __must_check
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int __copy_to_user(void __user *dst, const void *src, unsigned size)
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{
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int ret = 0;
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if (!__builtin_constant_p(size))
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return copy_user_generic((__force void *)dst, src, size);
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switch (size) {
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case 1:__put_user_asm(*(u8 *)src, (u8 __user *)dst,
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ret, "b", "b", "iq", 1);
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return ret;
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case 2:__put_user_asm(*(u16 *)src, (u16 __user *)dst,
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ret, "w", "w", "ir", 2);
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return ret;
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case 4:__put_user_asm(*(u32 *)src, (u32 __user *)dst,
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ret, "l", "k", "ir", 4);
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return ret;
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case 8:__put_user_asm(*(u64 *)src, (u64 __user *)dst,
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ret, "q", "", "ir", 8);
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return ret;
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case 10:
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__put_user_asm(*(u64 *)src, (u64 __user *)dst,
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ret, "q", "", "ir", 10);
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if (unlikely(ret))
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return ret;
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asm("":::"memory");
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__put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst,
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ret, "w", "w", "ir", 2);
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return ret;
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case 16:
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__put_user_asm(*(u64 *)src, (u64 __user *)dst,
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ret, "q", "", "ir", 16);
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if (unlikely(ret))
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return ret;
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asm("":::"memory");
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__put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst,
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ret, "q", "", "ir", 8);
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return ret;
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default:
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return copy_user_generic((__force void *)dst, src, size);
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}
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}
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static __always_inline __must_check
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int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
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{
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int ret = 0;
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if (!__builtin_constant_p(size))
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return copy_user_generic((__force void *)dst,
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(__force void *)src, size);
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switch (size) {
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case 1: {
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u8 tmp;
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__get_user_asm(tmp, (u8 __user *)src,
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ret, "b", "b", "=q", 1);
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if (likely(!ret))
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__put_user_asm(tmp, (u8 __user *)dst,
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ret, "b", "b", "iq", 1);
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return ret;
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}
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case 2: {
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u16 tmp;
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__get_user_asm(tmp, (u16 __user *)src,
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ret, "w", "w", "=r", 2);
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if (likely(!ret))
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__put_user_asm(tmp, (u16 __user *)dst,
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ret, "w", "w", "ir", 2);
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return ret;
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}
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case 4: {
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u32 tmp;
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__get_user_asm(tmp, (u32 __user *)src,
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ret, "l", "k", "=r", 4);
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if (likely(!ret))
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__put_user_asm(tmp, (u32 __user *)dst,
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ret, "l", "k", "ir", 4);
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return ret;
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}
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case 8: {
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u64 tmp;
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__get_user_asm(tmp, (u64 __user *)src,
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ret, "q", "", "=r", 8);
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if (likely(!ret))
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__put_user_asm(tmp, (u64 __user *)dst,
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ret, "q", "", "ir", 8);
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return ret;
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}
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default:
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return copy_user_generic((__force void *)dst,
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(__force void *)src, size);
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}
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}
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__must_check long
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strncpy_from_user(char *dst, const char __user *src, long count);
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__must_check long
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__strncpy_from_user(char *dst, const char __user *src, long count);
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__must_check long strnlen_user(const char __user *str, long n);
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__must_check long __strnlen_user(const char __user *str, long n);
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__must_check long strlen_user(const char __user *str);
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__must_check unsigned long clear_user(void __user *mem, unsigned long len);
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__must_check unsigned long __clear_user(void __user *mem, unsigned long len);
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__must_check long __copy_from_user_inatomic(void *dst, const void __user *src,
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unsigned size);
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static __must_check __always_inline int
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__copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
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{
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return copy_user_generic((__force void *)dst, src, size);
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}
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#define ARCH_HAS_NOCACHE_UACCESS 1
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extern long __copy_user_nocache(void *dst, const void __user *src,
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unsigned size, int zerorest);
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static inline int __copy_from_user_nocache(void *dst, const void __user *src,
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unsigned size)
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{
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might_sleep();
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return __copy_user_nocache(dst, src, size, 1);
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}
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static inline int __copy_from_user_inatomic_nocache(void *dst,
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const void __user *src,
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unsigned size)
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{
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return __copy_user_nocache(dst, src, size, 0);
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}
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#endif /* __X86_64_UACCESS_H */
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