David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 1 | /* MN10300 Userspace accessor functions |
| 2 | * |
| 3 | * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd. |
| 4 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. |
| 5 | * Written by David Howells (dhowells@redhat.com) |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU General Public Licence |
| 9 | * as published by the Free Software Foundation; either version |
| 10 | * 2 of the Licence, or (at your option) any later version. |
| 11 | */ |
Al Viro | ae7cc57 | 2016-08-20 16:33:10 -0400 | [diff] [blame] | 12 | #include <linux/uaccess.h> |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 13 | |
| 14 | unsigned long |
| 15 | __generic_copy_to_user(void *to, const void *from, unsigned long n) |
| 16 | { |
| 17 | if (access_ok(VERIFY_WRITE, to, n)) |
| 18 | __copy_user(to, from, n); |
| 19 | return n; |
| 20 | } |
| 21 | |
| 22 | unsigned long |
| 23 | __generic_copy_from_user(void *to, const void *from, unsigned long n) |
| 24 | { |
| 25 | if (access_ok(VERIFY_READ, from, n)) |
| 26 | __copy_user_zeroing(to, from, n); |
Al Viro | ae7cc57 | 2016-08-20 16:33:10 -0400 | [diff] [blame] | 27 | else |
| 28 | memset(to, 0, n); |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 29 | return n; |
| 30 | } |
| 31 | |
| 32 | /* |
| 33 | * Copy a null terminated string from userspace. |
| 34 | */ |
| 35 | #define __do_strncpy_from_user(dst, src, count, res) \ |
| 36 | do { \ |
| 37 | int w; \ |
| 38 | asm volatile( \ |
| 39 | " mov %1,%0\n" \ |
| 40 | " cmp 0,%1\n" \ |
| 41 | " beq 2f\n" \ |
| 42 | "0:\n" \ |
| 43 | " movbu (%5),%2\n" \ |
| 44 | "1:\n" \ |
| 45 | " movbu %2,(%6)\n" \ |
| 46 | " inc %5\n" \ |
| 47 | " inc %6\n" \ |
| 48 | " cmp 0,%2\n" \ |
| 49 | " beq 2f\n" \ |
| 50 | " add -1,%1\n" \ |
| 51 | " bne 0b\n" \ |
| 52 | "2:\n" \ |
| 53 | " sub %1,%0\n" \ |
| 54 | "3:\n" \ |
| 55 | " .section .fixup,\"ax\"\n" \ |
| 56 | "4:\n" \ |
| 57 | " mov %3,%0\n" \ |
| 58 | " jmp 3b\n" \ |
| 59 | " .previous\n" \ |
| 60 | " .section __ex_table,\"a\"\n" \ |
| 61 | " .balign 4\n" \ |
| 62 | " .long 0b,4b\n" \ |
| 63 | " .long 1b,4b\n" \ |
| 64 | " .previous" \ |
| 65 | :"=&r"(res), "=r"(count), "=&r"(w) \ |
| 66 | :"i"(-EFAULT), "1"(count), "a"(src), "a"(dst) \ |
Mark Salter | d6bb7a1 | 2010-01-08 14:43:16 -0800 | [diff] [blame] | 67 | : "memory", "cc"); \ |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 68 | } while (0) |
| 69 | |
| 70 | long |
| 71 | __strncpy_from_user(char *dst, const char *src, long count) |
| 72 | { |
| 73 | long res; |
| 74 | __do_strncpy_from_user(dst, src, count, res); |
| 75 | return res; |
| 76 | } |
| 77 | |
| 78 | long |
| 79 | strncpy_from_user(char *dst, const char *src, long count) |
| 80 | { |
| 81 | long res = -EFAULT; |
| 82 | if (access_ok(VERIFY_READ, src, 1)) |
| 83 | __do_strncpy_from_user(dst, src, count, res); |
| 84 | return res; |
| 85 | } |
| 86 | |
| 87 | |
| 88 | /* |
| 89 | * Clear a userspace memory |
| 90 | */ |
| 91 | #define __do_clear_user(addr, size) \ |
| 92 | do { \ |
| 93 | int w; \ |
| 94 | asm volatile( \ |
| 95 | " cmp 0,%0\n" \ |
| 96 | " beq 1f\n" \ |
| 97 | " clr %1\n" \ |
| 98 | "0: movbu %1,(%3,%2)\n" \ |
| 99 | " inc %3\n" \ |
| 100 | " cmp %0,%3\n" \ |
| 101 | " bne 0b\n" \ |
| 102 | "1:\n" \ |
| 103 | " sub %3,%0\n" \ |
| 104 | "2:\n" \ |
| 105 | ".section .fixup,\"ax\"\n" \ |
| 106 | "3: jmp 2b\n" \ |
| 107 | ".previous\n" \ |
| 108 | ".section __ex_table,\"a\"\n" \ |
| 109 | " .balign 4\n" \ |
| 110 | " .long 0b,3b\n" \ |
| 111 | ".previous\n" \ |
| 112 | : "+r"(size), "=&r"(w) \ |
| 113 | : "a"(addr), "d"(0) \ |
Mark Salter | d6bb7a1 | 2010-01-08 14:43:16 -0800 | [diff] [blame] | 114 | : "memory", "cc"); \ |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 115 | } while (0) |
| 116 | |
| 117 | unsigned long |
| 118 | __clear_user(void *to, unsigned long n) |
| 119 | { |
| 120 | __do_clear_user(to, n); |
| 121 | return n; |
| 122 | } |
| 123 | |
| 124 | unsigned long |
| 125 | clear_user(void *to, unsigned long n) |
| 126 | { |
| 127 | if (access_ok(VERIFY_WRITE, to, n)) |
| 128 | __do_clear_user(to, n); |
| 129 | return n; |
| 130 | } |
| 131 | |
| 132 | /* |
| 133 | * Return the size of a string (including the ending 0) |
| 134 | * |
| 135 | * Return 0 on exception, a value greater than N if too long |
| 136 | */ |
| 137 | long strnlen_user(const char *s, long n) |
| 138 | { |
| 139 | unsigned long res, w; |
| 140 | |
| 141 | if (!__addr_ok(s)) |
| 142 | return 0; |
| 143 | |
| 144 | if (n < 0 || n + (u_long) s > current_thread_info()->addr_limit.seg) |
| 145 | n = current_thread_info()->addr_limit.seg - (u_long)s; |
| 146 | |
| 147 | asm volatile( |
| 148 | "0: cmp %4,%0\n" |
| 149 | " beq 2f\n" |
| 150 | "1: movbu (%0,%3),%1\n" |
| 151 | " inc %0\n" |
| 152 | " cmp 0,%1\n" |
| 153 | " beq 3f\n" |
| 154 | " bra 0b\n" |
| 155 | "2: clr %0\n" |
| 156 | "3:\n" |
| 157 | ".section .fixup,\"ax\"\n" |
| 158 | "4: jmp 2b\n" |
| 159 | ".previous\n" |
| 160 | ".section __ex_table,\"a\"\n" |
| 161 | " .balign 4\n" |
| 162 | " .long 1b,4b\n" |
| 163 | ".previous\n" |
| 164 | :"=d"(res), "=&r"(w) |
| 165 | :"0"(0), "a"(s), "r"(n) |
Mark Salter | d6bb7a1 | 2010-01-08 14:43:16 -0800 | [diff] [blame] | 166 | : "memory", "cc"); |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 167 | return res; |
| 168 | } |