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243 lines
6.9 KiB
243 lines
6.9 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
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/* |
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* uaccess.h: User space memore access functions. |
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* |
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* Copyright (C) 1996 David S. Miller ([email protected]) |
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* Copyright (C) 1996,1997 Jakub Jelinek ([email protected]) |
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*/ |
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#ifndef _ASM_UACCESS_H |
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#define _ASM_UACCESS_H |
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#include <linux/compiler.h> |
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#include <linux/string.h> |
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#include <asm/processor.h> |
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/* Sparc is not segmented, however we need to be able to fool access_ok() |
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* when doing system calls from kernel mode legitimately. |
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* |
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* "For historical reasons, these macros are grossly misnamed." -Linus |
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*/ |
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#define KERNEL_DS ((mm_segment_t) { 0 }) |
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#define USER_DS ((mm_segment_t) { -1 }) |
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#define get_fs() (current->thread.current_ds) |
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#define set_fs(val) ((current->thread.current_ds) = (val)) |
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#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) |
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/* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test |
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* can be fairly lightweight. |
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* No one can read/write anything from userland in the kernel space by setting |
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* large size and address near to PAGE_OFFSET - a fault will break his intentions. |
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*/ |
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#define __user_ok(addr, size) ({ (void)(size); (addr) < STACK_TOP; }) |
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#define __kernel_ok (uaccess_kernel()) |
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#define __access_ok(addr, size) (__user_ok((addr) & get_fs().seg, (size))) |
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#define access_ok(addr, size) __access_ok((unsigned long)(addr), size) |
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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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* 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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#define put_user(x, ptr) ({ \ |
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unsigned long __pu_addr = (unsigned long)(ptr); \ |
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__chk_user_ptr(ptr); \ |
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__put_user_check((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr))); \ |
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}) |
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#define get_user(x, ptr) ({ \ |
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unsigned long __gu_addr = (unsigned long)(ptr); \ |
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__chk_user_ptr(ptr); \ |
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__get_user_check((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr))); \ |
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}) |
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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) \ |
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__put_user_nocheck((__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)), __typeof__(*(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 __put_user_check(x, addr, size) ({ \ |
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register int __pu_ret; \ |
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if (__access_ok(addr, size)) { \ |
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switch (size) { \ |
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case 1: \ |
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__put_user_asm(x, b, addr, __pu_ret); \ |
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break; \ |
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case 2: \ |
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__put_user_asm(x, h, addr, __pu_ret); \ |
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break; \ |
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case 4: \ |
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__put_user_asm(x, , addr, __pu_ret); \ |
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break; \ |
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case 8: \ |
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__put_user_asm(x, d, addr, __pu_ret); \ |
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break; \ |
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default: \ |
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__pu_ret = __put_user_bad(); \ |
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break; \ |
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} \ |
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} else { \ |
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__pu_ret = -EFAULT; \ |
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} \ |
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__pu_ret; \ |
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}) |
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#define __put_user_nocheck(x, addr, size) ({ \ |
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register int __pu_ret; \ |
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switch (size) { \ |
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case 1: __put_user_asm(x, b, addr, __pu_ret); break; \ |
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case 2: __put_user_asm(x, h, addr, __pu_ret); break; \ |
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case 4: __put_user_asm(x, , addr, __pu_ret); break; \ |
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case 8: __put_user_asm(x, d, addr, __pu_ret); break; \ |
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default: __pu_ret = __put_user_bad(); break; \ |
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} \ |
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__pu_ret; \ |
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}) |
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#define __put_user_asm(x, size, addr, ret) \ |
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__asm__ __volatile__( \ |
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"/* Put user asm, inline. */\n" \ |
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"1:\t" "st"#size " %1, %2\n\t" \ |
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"clr %0\n" \ |
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"2:\n\n\t" \ |
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".section .fixup,#alloc,#execinstr\n\t" \ |
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".align 4\n" \ |
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"3:\n\t" \ |
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"b 2b\n\t" \ |
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" mov %3, %0\n\t" \ |
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".previous\n\n\t" \ |
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".section __ex_table,#alloc\n\t" \ |
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".align 4\n\t" \ |
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".word 1b, 3b\n\t" \ |
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".previous\n\n\t" \ |
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: "=&r" (ret) : "r" (x), "m" (*__m(addr)), \ |
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"i" (-EFAULT)) |
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int __put_user_bad(void); |
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#define __get_user_check(x, addr, size, type) ({ \ |
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register int __gu_ret; \ |
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register unsigned long __gu_val; \ |
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if (__access_ok(addr, size)) { \ |
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switch (size) { \ |
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case 1: \ |
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__get_user_asm(__gu_val, ub, addr, __gu_ret); \ |
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break; \ |
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case 2: \ |
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__get_user_asm(__gu_val, uh, addr, __gu_ret); \ |
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break; \ |
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case 4: \ |
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__get_user_asm(__gu_val, , addr, __gu_ret); \ |
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break; \ |
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case 8: \ |
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__get_user_asm(__gu_val, d, addr, __gu_ret); \ |
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break; \ |
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default: \ |
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__gu_val = 0; \ |
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__gu_ret = __get_user_bad(); \ |
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break; \ |
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} \ |
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} else { \ |
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__gu_val = 0; \ |
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__gu_ret = -EFAULT; \ |
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} \ |
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x = (__force type) __gu_val; \ |
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__gu_ret; \ |
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}) |
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#define __get_user_nocheck(x, addr, size, type) ({ \ |
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register int __gu_ret; \ |
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register unsigned long __gu_val; \ |
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switch (size) { \ |
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case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \ |
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case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \ |
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case 4: __get_user_asm(__gu_val, , addr, __gu_ret); break; \ |
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case 8: __get_user_asm(__gu_val, d, addr, __gu_ret); break; \ |
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default: \ |
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__gu_val = 0; \ |
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__gu_ret = __get_user_bad(); \ |
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break; \ |
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} \ |
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x = (__force type) __gu_val; \ |
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__gu_ret; \ |
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}) |
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#define __get_user_asm(x, size, addr, ret) \ |
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__asm__ __volatile__( \ |
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"/* Get user asm, inline. */\n" \ |
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"1:\t" "ld"#size " %2, %1\n\t" \ |
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"clr %0\n" \ |
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"2:\n\n\t" \ |
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".section .fixup,#alloc,#execinstr\n\t" \ |
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".align 4\n" \ |
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"3:\n\t" \ |
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"clr %1\n\t" \ |
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"b 2b\n\t" \ |
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" mov %3, %0\n\n\t" \ |
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".previous\n\t" \ |
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".section __ex_table,#alloc\n\t" \ |
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".align 4\n\t" \ |
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".word 1b, 3b\n\n\t" \ |
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".previous\n\t" \ |
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: "=&r" (ret), "=&r" (x) : "m" (*__m(addr)), \ |
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"i" (-EFAULT)) |
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int __get_user_bad(void); |
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unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size); |
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static inline unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) |
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{ |
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return __copy_user(to, (__force void __user *) from, n); |
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} |
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static inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) |
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{ |
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return __copy_user((__force void __user *) to, from, n); |
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} |
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#define INLINE_COPY_FROM_USER |
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#define INLINE_COPY_TO_USER |
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static inline unsigned long __clear_user(void __user *addr, unsigned long size) |
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{ |
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unsigned long ret; |
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__asm__ __volatile__ ( |
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"mov %2, %%o1\n" |
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"call __bzero\n\t" |
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" mov %1, %%o0\n\t" |
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"mov %%o0, %0\n" |
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: "=r" (ret) : "r" (addr), "r" (size) : |
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"o0", "o1", "o2", "o3", "o4", "o5", "o7", |
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"g1", "g2", "g3", "g4", "g5", "g7", "cc"); |
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return ret; |
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} |
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static inline unsigned long clear_user(void __user *addr, unsigned long n) |
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{ |
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if (n && __access_ok((unsigned long) addr, n)) |
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return __clear_user(addr, n); |
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else |
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return n; |
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} |
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__must_check long strnlen_user(const char __user *str, long n); |
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#endif /* _ASM_UACCESS_H */
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