parisc: Fix kernel crash with reversed copy_from_user()
[linux-2.6-block.git] / arch / parisc / lib / fixup.S
CommitLineData
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1/*
2 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
3 *
4 * Copyright (C) 2004 Randolph Chung <tausq@debian.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2, or (at your option)
9 * any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 *
20 * Fixup routines for kernel exception handling.
21 */
0013a854 22#include <asm/asm-offsets.h>
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23#include <asm/assembly.h>
24#include <asm/errno.h>
0b3d643f 25#include <linux/linkage.h>
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26
27#ifdef CONFIG_SMP
28 .macro get_fault_ip t1 t2
29 addil LT%__per_cpu_offset,%r27
30 LDREG RT%__per_cpu_offset(%r1),\t1
31 /* t2 = smp_processor_id() */
32 mfctl 30,\t2
33 ldw TI_CPU(\t2),\t2
0b3d643f 34#ifdef CONFIG_64BIT
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35 extrd,u \t2,63,32,\t2
36#endif
37 /* t2 = &__per_cpu_offset[smp_processor_id()]; */
61520e1f 38 LDREGX \t2(\t1),\t2
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39 addil LT%exception_data,%r27
40 LDREG RT%exception_data(%r1),\t1
6ddb798f 41 /* t1 = this_cpu_ptr(&exception_data) */
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42 add,l \t1,\t2,\t1
43 /* t1 = t1->fault_ip */
44 LDREG EXCDATA_IP(\t1), \t1
45 .endm
46#else
47 .macro get_fault_ip t1 t2
6ddb798f 48 /* t1 = this_cpu_ptr(&exception_data) */
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49 addil LT%exception_data,%r27
50 LDREG RT%exception_data(%r1),\t2
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51 /* t1 = t2->fault_ip */
52 LDREG EXCDATA_IP(\t2), \t1
53 .endm
54#endif
55
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56 .level LEVEL
57
dfcf753b 58 .text
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59 .section .fixup, "ax"
60
61 /* get_user() fixups, store -EFAULT in r8, and 0 in r9 */
0b3d643f 62ENTRY(fixup_get_user_skip_1)
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63 get_fault_ip %r1,%r8
64 ldo 4(%r1), %r1
65 ldi -EFAULT, %r8
66 bv %r0(%r1)
67 copy %r0, %r9
0b3d643f 68ENDPROC(fixup_get_user_skip_1)
1da177e4 69
0b3d643f 70ENTRY(fixup_get_user_skip_2)
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71 get_fault_ip %r1,%r8
72 ldo 8(%r1), %r1
73 ldi -EFAULT, %r8
74 bv %r0(%r1)
75 copy %r0, %r9
0b3d643f 76ENDPROC(fixup_get_user_skip_2)
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77
78 /* put_user() fixups, store -EFAULT in r8 */
0b3d643f 79ENTRY(fixup_put_user_skip_1)
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80 get_fault_ip %r1,%r8
81 ldo 4(%r1), %r1
82 bv %r0(%r1)
83 ldi -EFAULT, %r8
0b3d643f 84ENDPROC(fixup_put_user_skip_1)
1da177e4 85
0b3d643f 86ENTRY(fixup_put_user_skip_2)
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87 get_fault_ip %r1,%r8
88 ldo 8(%r1), %r1
89 bv %r0(%r1)
90 ldi -EFAULT, %r8
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91ENDPROC(fixup_put_user_skip_2)
92