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(type, addr, size) \ 62 __range_ok((unsigned long)addr, (unsigned long)size) 63 64 /* 65 * These are the main single-value transfer routines. They automatically 66 * use the right size if we just have the right pointer type. 67 * 68 * This gets kind of ugly. We want to return _two_ values in "get_user()" 69 * and yet we don't want to do any pointers, because that is too much 70 * of a performance impact. Thus we have a few rather ugly macros here, 71 * and hide all the uglyness from the user. 72 * 73 * The "__xxx" versions of the user access functions are versions that 74 * do not verify the address space, that must have been done previously 75 * with a separate "access_ok()" call (this is used when we do multiple 76 * accesses to the same area of user memory). 77 * 78 * As we use the same address space for kernel and user data on the 79 * PowerPC, we can just do these as direct assignments. (Of course, the 80 * exception handling means that it's no longer "just"...) 81 */ 82 #define get_user(x, ptr) \ 83 __get_user_check((x), (ptr), sizeof(*(ptr))) 84 #define put_user(x, ptr) \ 85 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 86 87 #define __get_user(x, ptr) \ 88 __get_user_nocheck((x), (ptr), sizeof(*(ptr))) 89 #define __put_user(x, ptr) \ 90 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 91 92 extern long __put_user_bad(void); 93 94 #define __put_user_nocheck(x, ptr, size) \ 95 ({ \ 96 long __pu_err; \ 97 __put_user_size((x), (ptr), (size), __pu_err); \ 98 __pu_err; \ 99 }) 100 101 #define __put_user_check(x, ptr, size) \ 102 ({ \ 103 long __pu_err = -EFAULT; \ 104 __typeof__(*(ptr)) *__pu_addr = (ptr); \ 105 if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ 106 __put_user_size((x), __pu_addr, (size), __pu_err); \ 107 __pu_err; \ 108 }) 109 110 #define __put_user_size(x, ptr, size, retval) \ 111 do { \ 112 retval = 0; \ 113 switch (size) { \ 114 case 1: __put_user_asm(x, ptr, retval, "l.sb"); break; \ 115 case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \ 116 case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \ 117 case 8: __put_user_asm2(x, ptr, retval); break; \ 118 default: __put_user_bad(); \ 119 } \ 120 } while (0) 121 122 struct __large_struct { 123 unsigned long buf[100]; 124 }; 125 #define __m(x) (*(struct __large_struct *)(x)) 126 127 /* 128 * We don't tell gcc that we are accessing memory, but this is OK 129 * because we do not write to any memory gcc knows about, so there 130 * are no aliasing issues. 131 */ 132 #define __put_user_asm(x, addr, err, op) \ 133 __asm__ __volatile__( \ 134 "1: "op" 0(%2),%1\n" \ 135 "2:\n" \ 136 ".section .fixup,\"ax\"\n" \ 137 "3: l.addi %0,r0,%3\n" \ 138 " l.j 2b\n" \ 139 " l.nop\n" \ 140 ".previous\n" \ 141 ".section __ex_table,\"a\"\n" \ 142 " .align 2\n" \ 143 " .long 1b,3b\n" \ 144 ".previous" \ 145 : "=r"(err) \ 146 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)) 147 148 #define __put_user_asm2(x, addr, err) \ 149 __asm__ __volatile__( \ 150 "1: l.sw 0(%2),%1\n" \ 151 "2: l.sw 4(%2),%H1\n" \ 152 "3:\n" \ 153 ".section .fixup,\"ax\"\n" \ 154 "4: l.addi %0,r0,%3\n" \ 155 " l.j 3b\n" \ 156 " l.nop\n" \ 157 ".previous\n" \ 158 ".section __ex_table,\"a\"\n" \ 159 " .align 2\n" \ 160 " .long 1b,4b\n" \ 161 " .long 2b,4b\n" \ 162 ".previous" \ 163 : "=r"(err) \ 164 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)) 165 166 #define __get_user_nocheck(x, ptr, size) \ 167 ({ \ 168 long __gu_err, __gu_val; \ 169 __get_user_size(__gu_val, (ptr), (size), __gu_err); \ 170 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 171 __gu_err; \ 172 }) 173 174 #define __get_user_check(x, ptr, size) \ 175 ({ \ 176 long __gu_err = -EFAULT, __gu_val = 0; \ 177 const __typeof__(*(ptr)) * __gu_addr = (ptr); \ 178 if (access_ok(VERIFY_READ, __gu_addr, size)) \ 179 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 180 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 181 __gu_err; \ 182 }) 183 184 extern long __get_user_bad(void); 185 186 #define __get_user_size(x, ptr, size, retval) \ 187 do { \ 188 retval = 0; \ 189 switch (size) { \ 190 case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \ 191 case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \ 192 case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \ 193 case 8: __get_user_asm2(x, ptr, retval); break; \ 194 default: (x) = __get_user_bad(); \ 195 } \ 196 } while (0) 197 198 #define __get_user_asm(x, addr, err, op) \ 199 __asm__ __volatile__( \ 200 "1: "op" %1,0(%2)\n" \ 201 "2:\n" \ 202 ".section .fixup,\"ax\"\n" \ 203 "3: l.addi %0,r0,%3\n" \ 204 " l.addi %1,r0,0\n" \ 205 " l.j 2b\n" \ 206 " l.nop\n" \ 207 ".previous\n" \ 208 ".section __ex_table,\"a\"\n" \ 209 " .align 2\n" \ 210 " .long 1b,3b\n" \ 211 ".previous" \ 212 : "=r"(err), "=r"(x) \ 213 : "r"(addr), "i"(-EFAULT), "0"(err)) 214 215 #define __get_user_asm2(x, addr, err) \ 216 __asm__ __volatile__( \ 217 "1: l.lwz %1,0(%2)\n" \ 218 "2: l.lwz %H1,4(%2)\n" \ 219 "3:\n" \ 220 ".section .fixup,\"ax\"\n" \ 221 "4: l.addi %0,r0,%3\n" \ 222 " l.addi %1,r0,0\n" \ 223 " l.addi %H1,r0,0\n" \ 224 " l.j 3b\n" \ 225 " l.nop\n" \ 226 ".previous\n" \ 227 ".section __ex_table,\"a\"\n" \ 228 " .align 2\n" \ 229 " .long 1b,4b\n" \ 230 " .long 2b,4b\n" \ 231 ".previous" \ 232 : "=r"(err), "=&r"(x) \ 233 : "r"(addr), "i"(-EFAULT), "0"(err)) 234 235 /* more complex routines */ 236 237 extern unsigned long __must_check 238 __copy_tofrom_user(void *to, const void *from, unsigned long size); 239 static inline unsigned long 240 raw_copy_from_user(void *to, const void __user *from, unsigned long size) 241 { 242 return __copy_tofrom_user(to, (__force const void *)from, size); 243 } 244 static inline unsigned long 245 raw_copy_to_user(void *to, const void __user *from, unsigned long size) 246 { 247 return __copy_tofrom_user((__force void *)to, from, size); 248 } 249 #define INLINE_COPY_FROM_USER 250 #define INLINE_COPY_TO_USER 251 252 extern unsigned long __clear_user(void *addr, unsigned long size); 253 254 static inline __must_check unsigned long 255 clear_user(void *addr, unsigned long size) 256 { 257 if (likely(access_ok(VERIFY_WRITE, addr, size))) 258 size = __clear_user(addr, size); 259 return size; 260 } 261 262 #define user_addr_max() \ 263 (uaccess_kernel() ? ~0UL : TASK_SIZE) 264 265 extern long strncpy_from_user(char *dest, const char __user *src, long count); 266 267 extern __must_check long strlen_user(const char __user *str); 268 extern __must_check long strnlen_user(const char __user *str, long n); 269 270 #endif /* __ASM_OPENRISC_UACCESS_H */ 271