3c46bdcaec
m68k: implement __clear_user(), which is needed by fs/signalfd.c Since we always let the MMU do all checking, clear_user() and __clear_user() are identical. The old clear_user() is renamed to __clear_user() for consistency. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
222 lines
4.2 KiB
C
222 lines
4.2 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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* for more details.
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*/
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#include <linux/module.h>
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#include <asm/uaccess.h>
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unsigned long __generic_copy_from_user(void *to, const void __user *from,
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unsigned long n)
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{
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unsigned long tmp, res;
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asm volatile ("\n"
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" tst.l %0\n"
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" jeq 2f\n"
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"1: moves.l (%1)+,%3\n"
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" move.l %3,(%2)+\n"
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" subq.l #1,%0\n"
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" jne 1b\n"
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"2: btst #1,%5\n"
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" jeq 4f\n"
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"3: moves.w (%1)+,%3\n"
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" move.w %3,(%2)+\n"
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"4: btst #0,%5\n"
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" jeq 6f\n"
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"5: moves.b (%1)+,%3\n"
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" move.b %3,(%2)+\n"
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"6:\n"
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" .section .fixup,\"ax\"\n"
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" .even\n"
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"10: move.l %0,%3\n"
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"7: clr.l (%2)+\n"
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" subq.l #1,%3\n"
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" jne 7b\n"
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" lsl.l #2,%0\n"
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" btst #1,%5\n"
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" jeq 8f\n"
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"30: clr.w (%2)+\n"
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" addq.l #2,%0\n"
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"8: btst #0,%5\n"
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" jeq 6b\n"
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"50: clr.b (%2)+\n"
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" addq.l #1,%0\n"
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" jra 6b\n"
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" .previous\n"
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"\n"
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" .section __ex_table,\"a\"\n"
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" .align 4\n"
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" .long 1b,10b\n"
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" .long 3b,30b\n"
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" .long 5b,50b\n"
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" .previous"
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: "=d" (res), "+a" (from), "+a" (to), "=&r" (tmp)
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: "0" (n / 4), "d" (n & 3));
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return res;
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}
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EXPORT_SYMBOL(__generic_copy_from_user);
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unsigned long __generic_copy_to_user(void __user *to, const void *from,
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unsigned long n)
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{
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unsigned long tmp, res;
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asm volatile ("\n"
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" tst.l %0\n"
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" jeq 4f\n"
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"1: move.l (%1)+,%3\n"
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"2: moves.l %3,(%2)+\n"
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"3: subq.l #1,%0\n"
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" jne 1b\n"
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"4: btst #1,%5\n"
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" jeq 6f\n"
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" move.w (%1)+,%3\n"
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"5: moves.w %3,(%2)+\n"
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"6: btst #0,%5\n"
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" jeq 8f\n"
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" move.b (%1)+,%3\n"
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"7: moves.b %3,(%2)+\n"
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"8:\n"
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" .section .fixup,\"ax\"\n"
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" .even\n"
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"20: lsl.l #2,%0\n"
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"50: add.l %5,%0\n"
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" jra 8b\n"
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" .previous\n"
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"\n"
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" .section __ex_table,\"a\"\n"
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" .align 4\n"
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" .long 2b,20b\n"
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" .long 3b,20b\n"
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" .long 5b,50b\n"
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" .long 6b,50b\n"
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" .long 7b,50b\n"
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" .long 8b,50b\n"
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" .previous"
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: "=d" (res), "+a" (from), "+a" (to), "=&r" (tmp)
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: "0" (n / 4), "d" (n & 3));
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return res;
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}
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EXPORT_SYMBOL(__generic_copy_to_user);
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/*
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* Copy a null terminated string from userspace.
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*/
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long strncpy_from_user(char *dst, const char __user *src, long count)
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{
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long res;
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char c;
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if (count <= 0)
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return count;
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asm volatile ("\n"
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"1: moves.b (%2)+,%4\n"
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" move.b %4,(%1)+\n"
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" jeq 2f\n"
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" subq.l #1,%3\n"
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" jne 1b\n"
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"2: sub.l %3,%0\n"
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"3:\n"
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" .section .fixup,\"ax\"\n"
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" .even\n"
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"10: move.l %5,%0\n"
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" jra 3b\n"
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" .previous\n"
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"\n"
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" .section __ex_table,\"a\"\n"
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" .align 4\n"
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" .long 1b,10b\n"
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" .previous"
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: "=d" (res), "+a" (dst), "+a" (src), "+r" (count), "=&d" (c)
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: "i" (-EFAULT), "0" (count));
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return res;
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}
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EXPORT_SYMBOL(strncpy_from_user);
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/*
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* Return the size of a string (including the ending 0)
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*
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* Return 0 on exception, a value greater than N if too long
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*/
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long strnlen_user(const char __user *src, long n)
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{
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char c;
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long res;
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asm volatile ("\n"
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"1: subq.l #1,%1\n"
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" jmi 3f\n"
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"2: moves.b (%0)+,%2\n"
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" tst.b %2\n"
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" jne 1b\n"
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" jra 4f\n"
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"\n"
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"3: addq.l #1,%0\n"
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"4: sub.l %4,%0\n"
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"5:\n"
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" .section .fixup,\"ax\"\n"
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" .even\n"
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"20: sub.l %0,%0\n"
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" jra 5b\n"
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" .previous\n"
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"\n"
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" .section __ex_table,\"a\"\n"
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" .align 4\n"
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" .long 2b,20b\n"
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" .previous\n"
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: "=&a" (res), "+d" (n), "=&d" (c)
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: "0" (src), "r" (src));
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return res;
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}
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EXPORT_SYMBOL(strnlen_user);
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/*
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* Zero Userspace
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*/
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unsigned long __clear_user(void __user *to, unsigned long n)
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{
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unsigned long res;
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asm volatile ("\n"
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" tst.l %0\n"
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" jeq 3f\n"
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"1: moves.l %2,(%1)+\n"
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"2: subq.l #1,%0\n"
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" jne 1b\n"
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"3: btst #1,%4\n"
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" jeq 5f\n"
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"4: moves.w %2,(%1)+\n"
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"5: btst #0,%4\n"
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" jeq 7f\n"
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"6: moves.b %2,(%1)\n"
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"7:\n"
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" .section .fixup,\"ax\"\n"
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" .even\n"
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"10: lsl.l #2,%0\n"
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"40: add.l %4,%0\n"
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" jra 7b\n"
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" .previous\n"
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"\n"
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" .section __ex_table,\"a\"\n"
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" .align 4\n"
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" .long 1b,10b\n"
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" .long 2b,10b\n"
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" .long 4b,40b\n"
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" .long 5b,40b\n"
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" .long 6b,40b\n"
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" .long 7b,40b\n"
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" .previous"
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: "=d" (res), "+a" (to)
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: "r" (0), "0" (n / 4), "d" (n & 3));
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return res;
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}
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EXPORT_SYMBOL(__clear_user);
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