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 uaccess_kernel() (get_fs() == KERNEL_DS) 47 48 /* Ensure that the range from addr to addr+size is all within the process' 49 * address space 50 */ 51 static inline int __range_ok(unsigned long addr, unsigned long size) 52 { 53 const mm_segment_t fs = get_fs(); 54 55 return size <= fs && addr <= (fs - size); 56 } 57 58 #define access_ok(addr, size) \ 59 ({ \ 60 __chk_user_ptr(addr); \ 61 __range_ok((unsigned long)(addr), (size)); \ 62 }) 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)) __user *__pu_addr = (ptr); \ 105 if (access_ok(__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; \ 169 __get_user_size((x), (ptr), (size), __gu_err); \ 170 __gu_err; \ 171 }) 172 173 #define __get_user_check(x, ptr, size) \ 174 ({ \ 175 long __gu_err = -EFAULT; \ 176 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 177 if (access_ok(__gu_addr, size)) \ 178 __get_user_size((x), __gu_addr, (size), __gu_err); \ 179 else \ 180 (x) = (__typeof__(*(ptr))) 0; \ 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) = (__typeof__(*(ptr)))__get_user_bad(); \ 195 } \ 196 } while (0) 197 198 #define __get_user_asm(x, addr, err, op) \ 199 { \ 200 unsigned long __gu_tmp; \ 201 __asm__ __volatile__( \ 202 "1: "op" %1,0(%2)\n" \ 203 "2:\n" \ 204 ".section .fixup,\"ax\"\n" \ 205 "3: l.addi %0,r0,%3\n" \ 206 " l.addi %1,r0,0\n" \ 207 " l.j 2b\n" \ 208 " l.nop\n" \ 209 ".previous\n" \ 210 ".section __ex_table,\"a\"\n" \ 211 " .align 2\n" \ 212 " .long 1b,3b\n" \ 213 ".previous" \ 214 : "=r"(err), "=r"(__gu_tmp) \ 215 : "r"(addr), "i"(-EFAULT), "0"(err)); \ 216 (x) = (__typeof__(*(addr)))__gu_tmp; \ 217 } 218 219 #define __get_user_asm2(x, addr, err) \ 220 { \ 221 unsigned long long __gu_tmp; \ 222 __asm__ __volatile__( \ 223 "1: l.lwz %1,0(%2)\n" \ 224 "2: l.lwz %H1,4(%2)\n" \ 225 "3:\n" \ 226 ".section .fixup,\"ax\"\n" \ 227 "4: l.addi %0,r0,%3\n" \ 228 " l.addi %1,r0,0\n" \ 229 " l.addi %H1,r0,0\n" \ 230 " l.j 3b\n" \ 231 " l.nop\n" \ 232 ".previous\n" \ 233 ".section __ex_table,\"a\"\n" \ 234 " .align 2\n" \ 235 " .long 1b,4b\n" \ 236 " .long 2b,4b\n" \ 237 ".previous" \ 238 : "=r"(err), "=&r"(__gu_tmp) \ 239 : "r"(addr), "i"(-EFAULT), "0"(err)); \ 240 (x) = (__typeof__(*(addr)))( \ 241 (__typeof__((x)-(x)))__gu_tmp); \ 242 } 243 244 /* more complex routines */ 245 246 extern unsigned long __must_check 247 __copy_tofrom_user(void *to, const void *from, unsigned long size); 248 static inline unsigned long 249 raw_copy_from_user(void *to, const void __user *from, unsigned long size) 250 { 251 return __copy_tofrom_user(to, (__force const void *)from, size); 252 } 253 static inline unsigned long 254 raw_copy_to_user(void __user *to, const void *from, unsigned long size) 255 { 256 return __copy_tofrom_user((__force void *)to, from, size); 257 } 258 #define INLINE_COPY_FROM_USER 259 #define INLINE_COPY_TO_USER 260 261 extern unsigned long __clear_user(void __user *addr, unsigned long size); 262 263 static inline __must_check unsigned long 264 clear_user(void __user *addr, unsigned long size) 265 { 266 if (likely(access_ok(addr, size))) 267 size = __clear_user(addr, size); 268 return size; 269 } 270 271 #define user_addr_max() \ 272 (uaccess_kernel() ? ~0UL : TASK_SIZE) 273 274 extern long strncpy_from_user(char *dest, const char __user *src, long count); 275 276 extern __must_check long strnlen_user(const char __user *str, long n); 277 278 #endif /* __ASM_OPENRISC_UACCESS_H */ 279