164 строки
3.4 KiB
C
164 строки
3.4 KiB
C
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/*
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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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* Copyright (C) 2009, Wind River Systems Inc
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* Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
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*/
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#include <linux/export.h>
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#include <linux/uaccess.h>
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asm(".global __copy_from_user\n"
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" .type __copy_from_user, @function\n"
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"__copy_from_user:\n"
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" movi r2,7\n"
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" mov r3,r4\n"
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" bge r2,r6,1f\n"
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" xor r2,r4,r5\n"
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" andi r2,r2,3\n"
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" movi r7,3\n"
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" beq r2,zero,4f\n"
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"1: addi r6,r6,-1\n"
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" movi r2,-1\n"
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" beq r6,r2,3f\n"
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" mov r7,r2\n"
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"2: ldbu r2,0(r5)\n"
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" addi r6,r6,-1\n"
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" addi r5,r5,1\n"
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" stb r2,0(r3)\n"
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" addi r3,r3,1\n"
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" bne r6,r7,2b\n"
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"3:\n"
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" addi r2,r6,1\n"
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" ret\n"
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"13:mov r2,r6\n"
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" ret\n"
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"4: andi r2,r4,1\n"
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" cmpeq r2,r2,zero\n"
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" beq r2,zero,7f\n"
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"5: andi r2,r3,2\n"
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" beq r2,zero,6f\n"
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"9: ldhu r2,0(r5)\n"
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" addi r6,r6,-2\n"
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" addi r5,r5,2\n"
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" sth r2,0(r3)\n"
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" addi r3,r3,2\n"
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"6: bge r7,r6,1b\n"
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"10:ldw r2,0(r5)\n"
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" addi r6,r6,-4\n"
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" addi r5,r5,4\n"
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" stw r2,0(r3)\n"
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" addi r3,r3,4\n"
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" br 6b\n"
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"7: ldbu r2,0(r5)\n"
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" addi r6,r6,-1\n"
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" addi r5,r5,1\n"
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" addi r3,r4,1\n"
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" stb r2,0(r4)\n"
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" br 5b\n"
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".section __ex_table,\"a\"\n"
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".word 2b,3b\n"
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".word 9b,13b\n"
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".word 10b,13b\n"
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".word 7b,13b\n"
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".previous\n"
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);
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EXPORT_SYMBOL(__copy_from_user);
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asm(
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" .global __copy_to_user\n"
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" .type __copy_to_user, @function\n"
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"__copy_to_user:\n"
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" movi r2,7\n"
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" mov r3,r4\n"
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" bge r2,r6,1f\n"
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" xor r2,r4,r5\n"
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" andi r2,r2,3\n"
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" movi r7,3\n"
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" beq r2,zero,4f\n"
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/* Bail if we try to copy zero bytes */
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"1: addi r6,r6,-1\n"
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" movi r2,-1\n"
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" beq r6,r2,3f\n"
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/* Copy byte by byte for small copies and if src^dst != 0 */
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" mov r7,r2\n"
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"2: ldbu r2,0(r5)\n"
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" addi r5,r5,1\n"
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"9: stb r2,0(r3)\n"
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" addi r6,r6,-1\n"
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" addi r3,r3,1\n"
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" bne r6,r7,2b\n"
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"3: addi r2,r6,1\n"
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" ret\n"
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"13:mov r2,r6\n"
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" ret\n"
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/* If 'to' is an odd address byte copy */
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"4: andi r2,r4,1\n"
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" cmpeq r2,r2,zero\n"
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" beq r2,zero,7f\n"
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/* If 'to' is not divideable by four copy halfwords */
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"5: andi r2,r3,2\n"
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" beq r2,zero,6f\n"
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" ldhu r2,0(r5)\n"
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" addi r5,r5,2\n"
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"10:sth r2,0(r3)\n"
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" addi r6,r6,-2\n"
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" addi r3,r3,2\n"
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/* Copy words */
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"6: bge r7,r6,1b\n"
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" ldw r2,0(r5)\n"
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" addi r5,r5,4\n"
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"11:stw r2,0(r3)\n"
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" addi r6,r6,-4\n"
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" addi r3,r3,4\n"
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" br 6b\n"
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/* Copy remaining bytes */
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"7: ldbu r2,0(r5)\n"
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" addi r5,r5,1\n"
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" addi r3,r4,1\n"
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"12: stb r2,0(r4)\n"
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" addi r6,r6,-1\n"
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" br 5b\n"
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".section __ex_table,\"a\"\n"
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".word 9b,3b\n"
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".word 10b,13b\n"
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".word 11b,13b\n"
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".word 12b,13b\n"
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".previous\n");
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EXPORT_SYMBOL(__copy_to_user);
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long strncpy_from_user(char *__to, const char __user *__from, long __len)
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{
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int l = strnlen_user(__from, __len);
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int is_zt = 1;
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if (l > __len) {
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is_zt = 0;
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l = __len;
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}
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if (l == 0 || copy_from_user(__to, __from, l))
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return -EFAULT;
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if (is_zt)
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l--;
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return l;
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}
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long strnlen_user(const char __user *s, long n)
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{
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long i;
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for (i = 0; i < n; i++) {
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char c;
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if (get_user(c, s + i) == -EFAULT)
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return 0;
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if (c == 0)
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return i + 1;
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}
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return n + 1;
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}
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