1 /* 2 * OpenRISC Linux 3 * 4 * Linux architectural port borrowing liberally from similar works of 5 * others. All original copyrights apply as per the original source 6 * declaration. 7 * 8 * OpenRISC implementation: 9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> 10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> 11 * et al. 12 * 13 * This program is free software; you can redistribute it and/or modify 14 * it under the terms of the GNU General Public License as published by 15 * the Free Software Foundation; either version 2 of the License, or 16 * (at your option) any later version. 17 */ 18 19 #ifndef __ASM_OPENRISC_UACCESS_H 20 #define __ASM_OPENRISC_UACCESS_H 21 22 /* 23 * User space memory access functions 24 */ 25 #include <linux/prefetch.h> 26 #include <linux/string.h> 27 #include <asm/page.h> 28 #include <asm/extable.h> 29 30 /* 31 * The fs value determines whether argument validity checking should be 32 * performed or not. If get_fs() == USER_DS, checking is performed, with 33 * get_fs() == KERNEL_DS, checking is bypassed. 34 * 35 * For historical reasons, these macros are grossly misnamed. 36 */ 37 38 /* addr_limit is the maximum accessible address for the task. we misuse 39 * the KERNEL_DS and USER_DS values to both assign and compare the 40 * addr_limit values through the equally misnamed get/set_fs macros. 41 * (see above) 42 */ 43 44 #define KERNEL_DS (~0UL) 45 #define get_ds() (KERNEL_DS) 46 47 #define USER_DS (TASK_SIZE) 48 #define get_fs() (current_thread_info()->addr_limit) 49 #define set_fs(x) (current_thread_info()->addr_limit = (x)) 50 51 #define segment_eq(a, b) ((a) == (b)) 52 53 /* Ensure that the range from addr to addr+size is all within the process' 54 * address space 55 */ 56 #define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size)) 57 58 /* Ensure that addr is below task's addr_limit */ 59 #define __addr_ok(addr) ((unsigned long) addr < get_fs()) 60 61 #define access_ok(addr, size) \ 62 ({ \ 63 unsigned long __ao_addr = (unsigned long)(addr); \ 64 unsigned long __ao_size = (unsigned long)(size); \ 65 __range_ok(__ao_addr, __ao_size); \ 66 }) 67 68 /* 69 * These are the main single-value transfer routines. They automatically 70 * use the right size if we just have the right pointer type. 71 * 72 * This gets kind of ugly. We want to return _two_ values in "get_user()" 73 * and yet we don't want to do any pointers, because that is too much 74 * of a performance impact. Thus we have a few rather ugly macros here, 75 * and hide all the uglyness from the user. 76 * 77 * The "__xxx" versions of the user access functions are versions that 78 * do not verify the address space, that must have been done previously 79 * with a separate "access_ok()" call (this is used when we do multiple 80 * accesses to the same area of user memory). 81 * 82 * As we use the same address space for kernel and user data on the 83 * PowerPC, we can just do these as direct assignments. (Of course, the 84 * exception handling means that it's no longer "just"...) 85 */ 86 #define get_user(x, ptr) \ 87 __get_user_check((x), (ptr), sizeof(*(ptr))) 88 #define put_user(x, ptr) \ 89 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 90 91 #define __get_user(x, ptr) \ 92 __get_user_nocheck((x), (ptr), sizeof(*(ptr))) 93 #define __put_user(x, ptr) \ 94 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 95 96 extern long __put_user_bad(void); 97 98 #define __put_user_nocheck(x, ptr, size) \ 99 ({ \ 100 long __pu_err; \ 101 __put_user_size((x), (ptr), (size), __pu_err); \ 102 __pu_err; \ 103 }) 104 105 #define __put_user_check(x, ptr, size) \ 106 ({ \ 107 long __pu_err = -EFAULT; \ 108 __typeof__(*(ptr)) *__pu_addr = (ptr); \ 109 if (access_ok(__pu_addr, size)) \ 110 __put_user_size((x), __pu_addr, (size), __pu_err); \ 111 __pu_err; \ 112 }) 113 114 #define __put_user_size(x, ptr, size, retval) \ 115 do { \ 116 retval = 0; \ 117 switch (size) { \ 118 case 1: __put_user_asm(x, ptr, retval, "l.sb"); break; \ 119 case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \ 120 case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \ 121 case 8: __put_user_asm2(x, ptr, retval); break; \ 122 default: __put_user_bad(); \ 123 } \ 124 } while (0) 125 126 struct __large_struct { 127 unsigned long buf[100]; 128 }; 129 #define __m(x) (*(struct __large_struct *)(x)) 130 131 /* 132 * We don't tell gcc that we are accessing memory, but this is OK 133 * because we do not write to any memory gcc knows about, so there 134 * are no aliasing issues. 135 */ 136 #define __put_user_asm(x, addr, err, op) \ 137 __asm__ __volatile__( \ 138 "1: "op" 0(%2),%1\n" \ 139 "2:\n" \ 140 ".section .fixup,\"ax\"\n" \ 141 "3: l.addi %0,r0,%3\n" \ 142 " l.j 2b\n" \ 143 " l.nop\n" \ 144 ".previous\n" \ 145 ".section __ex_table,\"a\"\n" \ 146 " .align 2\n" \ 147 " .long 1b,3b\n" \ 148 ".previous" \ 149 : "=r"(err) \ 150 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)) 151 152 #define __put_user_asm2(x, addr, err) \ 153 __asm__ __volatile__( \ 154 "1: l.sw 0(%2),%1\n" \ 155 "2: l.sw 4(%2),%H1\n" \ 156 "3:\n" \ 157 ".section .fixup,\"ax\"\n" \ 158 "4: l.addi %0,r0,%3\n" \ 159 " l.j 3b\n" \ 160 " l.nop\n" \ 161 ".previous\n" \ 162 ".section __ex_table,\"a\"\n" \ 163 " .align 2\n" \ 164 " .long 1b,4b\n" \ 165 " .long 2b,4b\n" \ 166 ".previous" \ 167 : "=r"(err) \ 168 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)) 169 170 #define __get_user_nocheck(x, ptr, size) \ 171 ({ \ 172 long __gu_err, __gu_val; \ 173 __get_user_size(__gu_val, (ptr), (size), __gu_err); \ 174 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 175 __gu_err; \ 176 }) 177 178 #define __get_user_check(x, ptr, size) \ 179 ({ \ 180 long __gu_err = -EFAULT, __gu_val = 0; \ 181 const __typeof__(*(ptr)) * __gu_addr = (ptr); \ 182 if (access_ok(__gu_addr, size)) \ 183 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 184 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 185 __gu_err; \ 186 }) 187 188 extern long __get_user_bad(void); 189 190 #define __get_user_size(x, ptr, size, retval) \ 191 do { \ 192 retval = 0; \ 193 switch (size) { \ 194 case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \ 195 case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \ 196 case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \ 197 case 8: __get_user_asm2(x, ptr, retval); break; \ 198 default: (x) = __get_user_bad(); \ 199 } \ 200 } while (0) 201 202 #define __get_user_asm(x, addr, err, op) \ 203 __asm__ __volatile__( \ 204 "1: "op" %1,0(%2)\n" \ 205 "2:\n" \ 206 ".section .fixup,\"ax\"\n" \ 207 "3: l.addi %0,r0,%3\n" \ 208 " l.addi %1,r0,0\n" \ 209 " l.j 2b\n" \ 210 " l.nop\n" \ 211 ".previous\n" \ 212 ".section __ex_table,\"a\"\n" \ 213 " .align 2\n" \ 214 " .long 1b,3b\n" \ 215 ".previous" \ 216 : "=r"(err), "=r"(x) \ 217 : "r"(addr), "i"(-EFAULT), "0"(err)) 218 219 #define __get_user_asm2(x, addr, err) \ 220 __asm__ __volatile__( \ 221 "1: l.lwz %1,0(%2)\n" \ 222 "2: l.lwz %H1,4(%2)\n" \ 223 "3:\n" \ 224 ".section .fixup,\"ax\"\n" \ 225 "4: l.addi %0,r0,%3\n" \ 226 " l.addi %1,r0,0\n" \ 227 " l.addi %H1,r0,0\n" \ 228 " l.j 3b\n" \ 229 " l.nop\n" \ 230 ".previous\n" \ 231 ".section __ex_table,\"a\"\n" \ 232 " .align 2\n" \ 233 " .long 1b,4b\n" \ 234 " .long 2b,4b\n" \ 235 ".previous" \ 236 : "=r"(err), "=&r"(x) \ 237 : "r"(addr), "i"(-EFAULT), "0"(err)) 238 239 /* more complex routines */ 240 241 extern unsigned long __must_check 242 __copy_tofrom_user(void *to, const void *from, unsigned long size); 243 static inline unsigned long 244 raw_copy_from_user(void *to, const void __user *from, unsigned long size) 245 { 246 return __copy_tofrom_user(to, (__force const void *)from, size); 247 } 248 static inline unsigned long 249 raw_copy_to_user(void *to, const void __user *from, unsigned long size) 250 { 251 return __copy_tofrom_user((__force void *)to, from, size); 252 } 253 #define INLINE_COPY_FROM_USER 254 #define INLINE_COPY_TO_USER 255 256 extern unsigned long __clear_user(void *addr, unsigned long size); 257 258 static inline __must_check unsigned long 259 clear_user(void *addr, unsigned long size) 260 { 261 if (likely(access_ok(addr, size))) 262 size = __clear_user(addr, size); 263 return size; 264 } 265 266 #define user_addr_max() \ 267 (uaccess_kernel() ? ~0UL : TASK_SIZE) 268 269 extern long strncpy_from_user(char *dest, const char __user *src, long count); 270 271 extern __must_check long strnlen_user(const char __user *str, long n); 272 273 #endif /* __ASM_OPENRISC_UACCESS_H */ 274