1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * OpenRISC Linux 4 * 5 * Linux architectural port borrowing liberally from similar works of 6 * others. All original copyrights apply as per the original source 7 * declaration. 8 * 9 * OpenRISC implementation: 10 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> 11 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> 12 * et al. 13 */ 14 15 #ifndef __ASM_OPENRISC_UACCESS_H 16 #define __ASM_OPENRISC_UACCESS_H 17 18 /* 19 * User space memory access functions 20 */ 21 #include <linux/prefetch.h> 22 #include <linux/string.h> 23 #include <asm/page.h> 24 #include <asm/extable.h> 25 26 /* 27 * The fs value determines whether argument validity checking should be 28 * performed or not. If get_fs() == USER_DS, checking is performed, with 29 * get_fs() == KERNEL_DS, checking is bypassed. 30 * 31 * For historical reasons, these macros are grossly misnamed. 32 */ 33 34 /* addr_limit is the maximum accessible address for the task. we misuse 35 * the KERNEL_DS and USER_DS values to both assign and compare the 36 * addr_limit values through the equally misnamed get/set_fs macros. 37 * (see above) 38 */ 39 40 #define KERNEL_DS (~0UL) 41 42 #define USER_DS (TASK_SIZE) 43 #define get_fs() (current_thread_info()->addr_limit) 44 #define set_fs(x) (current_thread_info()->addr_limit = (x)) 45 46 #define segment_eq(a, b) ((a) == (b)) 47 48 /* Ensure that the range from addr to addr+size is all within the process' 49 * address space 50 */ 51 #define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size)) 52 53 /* Ensure that addr is below task's addr_limit */ 54 #define __addr_ok(addr) ((unsigned long) addr < get_fs()) 55 56 #define access_ok(addr, size) \ 57 ({ \ 58 unsigned long __ao_addr = (unsigned long)(addr); \ 59 unsigned long __ao_size = (unsigned long)(size); \ 60 __range_ok(__ao_addr, __ao_size); \ 61 }) 62 63 /* 64 * These are the main single-value transfer routines. They automatically 65 * use the right size if we just have the right pointer type. 66 * 67 * This gets kind of ugly. We want to return _two_ values in "get_user()" 68 * and yet we don't want to do any pointers, because that is too much 69 * of a performance impact. Thus we have a few rather ugly macros here, 70 * and hide all the uglyness from the user. 71 * 72 * The "__xxx" versions of the user access functions are versions that 73 * do not verify the address space, that must have been done previously 74 * with a separate "access_ok()" call (this is used when we do multiple 75 * accesses to the same area of user memory). 76 * 77 * As we use the same address space for kernel and user data on the 78 * PowerPC, we can just do these as direct assignments. (Of course, the 79 * exception handling means that it's no longer "just"...) 80 */ 81 #define get_user(x, ptr) \ 82 __get_user_check((x), (ptr), sizeof(*(ptr))) 83 #define put_user(x, ptr) \ 84 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 85 86 #define __get_user(x, ptr) \ 87 __get_user_nocheck((x), (ptr), sizeof(*(ptr))) 88 #define __put_user(x, ptr) \ 89 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 90 91 extern long __put_user_bad(void); 92 93 #define __put_user_nocheck(x, ptr, size) \ 94 ({ \ 95 long __pu_err; \ 96 __put_user_size((x), (ptr), (size), __pu_err); \ 97 __pu_err; \ 98 }) 99 100 #define __put_user_check(x, ptr, size) \ 101 ({ \ 102 long __pu_err = -EFAULT; \ 103 __typeof__(*(ptr)) *__pu_addr = (ptr); \ 104 if (access_ok(__pu_addr, size)) \ 105 __put_user_size((x), __pu_addr, (size), __pu_err); \ 106 __pu_err; \ 107 }) 108 109 #define __put_user_size(x, ptr, size, retval) \ 110 do { \ 111 retval = 0; \ 112 switch (size) { \ 113 case 1: __put_user_asm(x, ptr, retval, "l.sb"); break; \ 114 case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \ 115 case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \ 116 case 8: __put_user_asm2(x, ptr, retval); break; \ 117 default: __put_user_bad(); \ 118 } \ 119 } while (0) 120 121 struct __large_struct { 122 unsigned long buf[100]; 123 }; 124 #define __m(x) (*(struct __large_struct *)(x)) 125 126 /* 127 * We don't tell gcc that we are accessing memory, but this is OK 128 * because we do not write to any memory gcc knows about, so there 129 * are no aliasing issues. 130 */ 131 #define __put_user_asm(x, addr, err, op) \ 132 __asm__ __volatile__( \ 133 "1: "op" 0(%2),%1\n" \ 134 "2:\n" \ 135 ".section .fixup,\"ax\"\n" \ 136 "3: l.addi %0,r0,%3\n" \ 137 " l.j 2b\n" \ 138 " l.nop\n" \ 139 ".previous\n" \ 140 ".section __ex_table,\"a\"\n" \ 141 " .align 2\n" \ 142 " .long 1b,3b\n" \ 143 ".previous" \ 144 : "=r"(err) \ 145 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)) 146 147 #define __put_user_asm2(x, addr, err) \ 148 __asm__ __volatile__( \ 149 "1: l.sw 0(%2),%1\n" \ 150 "2: l.sw 4(%2),%H1\n" \ 151 "3:\n" \ 152 ".section .fixup,\"ax\"\n" \ 153 "4: l.addi %0,r0,%3\n" \ 154 " l.j 3b\n" \ 155 " l.nop\n" \ 156 ".previous\n" \ 157 ".section __ex_table,\"a\"\n" \ 158 " .align 2\n" \ 159 " .long 1b,4b\n" \ 160 " .long 2b,4b\n" \ 161 ".previous" \ 162 : "=r"(err) \ 163 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)) 164 165 #define __get_user_nocheck(x, ptr, size) \ 166 ({ \ 167 long __gu_err, __gu_val; \ 168 __get_user_size(__gu_val, (ptr), (size), __gu_err); \ 169 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 170 __gu_err; \ 171 }) 172 173 #define __get_user_check(x, ptr, size) \ 174 ({ \ 175 long __gu_err = -EFAULT, __gu_val = 0; \ 176 const __typeof__(*(ptr)) * __gu_addr = (ptr); \ 177 if (access_ok(__gu_addr, size)) \ 178 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 179 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 180 __gu_err; \ 181 }) 182 183 extern long __get_user_bad(void); 184 185 #define __get_user_size(x, ptr, size, retval) \ 186 do { \ 187 retval = 0; \ 188 switch (size) { \ 189 case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \ 190 case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \ 191 case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \ 192 case 8: __get_user_asm2(x, ptr, retval); break; \ 193 default: (x) = __get_user_bad(); \ 194 } \ 195 } while (0) 196 197 #define __get_user_asm(x, addr, err, op) \ 198 __asm__ __volatile__( \ 199 "1: "op" %1,0(%2)\n" \ 200 "2:\n" \ 201 ".section .fixup,\"ax\"\n" \ 202 "3: l.addi %0,r0,%3\n" \ 203 " l.addi %1,r0,0\n" \ 204 " l.j 2b\n" \ 205 " l.nop\n" \ 206 ".previous\n" \ 207 ".section __ex_table,\"a\"\n" \ 208 " .align 2\n" \ 209 " .long 1b,3b\n" \ 210 ".previous" \ 211 : "=r"(err), "=r"(x) \ 212 : "r"(addr), "i"(-EFAULT), "0"(err)) 213 214 #define __get_user_asm2(x, addr, err) \ 215 __asm__ __volatile__( \ 216 "1: l.lwz %1,0(%2)\n" \ 217 "2: l.lwz %H1,4(%2)\n" \ 218 "3:\n" \ 219 ".section .fixup,\"ax\"\n" \ 220 "4: l.addi %0,r0,%3\n" \ 221 " l.addi %1,r0,0\n" \ 222 " l.addi %H1,r0,0\n" \ 223 " l.j 3b\n" \ 224 " l.nop\n" \ 225 ".previous\n" \ 226 ".section __ex_table,\"a\"\n" \ 227 " .align 2\n" \ 228 " .long 1b,4b\n" \ 229 " .long 2b,4b\n" \ 230 ".previous" \ 231 : "=r"(err), "=&r"(x) \ 232 : "r"(addr), "i"(-EFAULT), "0"(err)) 233 234 /* more complex routines */ 235 236 extern unsigned long __must_check 237 __copy_tofrom_user(void *to, const void *from, unsigned long size); 238 static inline unsigned long 239 raw_copy_from_user(void *to, const void __user *from, unsigned long size) 240 { 241 return __copy_tofrom_user(to, (__force const void *)from, size); 242 } 243 static inline unsigned long 244 raw_copy_to_user(void *to, const void __user *from, unsigned long size) 245 { 246 return __copy_tofrom_user((__force void *)to, from, size); 247 } 248 #define INLINE_COPY_FROM_USER 249 #define INLINE_COPY_TO_USER 250 251 extern unsigned long __clear_user(void *addr, unsigned long size); 252 253 static inline __must_check unsigned long 254 clear_user(void *addr, unsigned long size) 255 { 256 if (likely(access_ok(addr, size))) 257 size = __clear_user(addr, size); 258 return size; 259 } 260 261 #define user_addr_max() \ 262 (uaccess_kernel() ? ~0UL : TASK_SIZE) 263 264 extern long strncpy_from_user(char *dest, const char __user *src, long count); 265 266 extern __must_check long strnlen_user(const char __user *str, long n); 267 268 #endif /* __ASM_OPENRISC_UACCESS_H */ 269