1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ARCH_POWERPC_UACCESS_H 3 #define _ARCH_POWERPC_UACCESS_H 4 5 #include <asm/asm-compat.h> 6 #include <asm/ppc_asm.h> 7 #include <asm/processor.h> 8 #include <asm/page.h> 9 #include <asm/extable.h> 10 11 /* 12 * The fs value determines whether argument validity checking should be 13 * performed or not. If get_fs() == USER_DS, checking is performed, with 14 * get_fs() == KERNEL_DS, checking is bypassed. 15 * 16 * For historical reasons, these macros are grossly misnamed. 17 * 18 * The fs/ds values are now the highest legal address in the "segment". 19 * This simplifies the checking in the routines below. 20 */ 21 22 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 23 24 #define KERNEL_DS MAKE_MM_SEG(~0UL) 25 #ifdef __powerpc64__ 26 /* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */ 27 #define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1) 28 #else 29 #define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) 30 #endif 31 32 #define get_ds() (KERNEL_DS) 33 #define get_fs() (current->thread.fs) 34 #define set_fs(val) (current->thread.fs = (val)) 35 36 #define segment_eq(a, b) ((a).seg == (b).seg) 37 38 #define user_addr_max() (get_fs().seg) 39 40 #ifdef __powerpc64__ 41 /* 42 * This check is sufficient because there is a large enough 43 * gap between user addresses and the kernel addresses 44 */ 45 #define __access_ok(addr, size, segment) \ 46 (((addr) <= (segment).seg) && ((size) <= (segment).seg)) 47 48 #else 49 50 #define __access_ok(addr, size, segment) \ 51 (((addr) <= (segment).seg) && \ 52 (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr))))) 53 54 #endif 55 56 #define access_ok(type, addr, size) \ 57 (__chk_user_ptr(addr), \ 58 __access_ok((__force unsigned long)(addr), (size), get_fs())) 59 60 /* 61 * These are the main single-value transfer routines. They automatically 62 * use the right size if we just have the right pointer type. 63 * 64 * This gets kind of ugly. We want to return _two_ values in "get_user()" 65 * and yet we don't want to do any pointers, because that is too much 66 * of a performance impact. Thus we have a few rather ugly macros here, 67 * and hide all the ugliness from the user. 68 * 69 * The "__xxx" versions of the user access functions are versions that 70 * do not verify the address space, that must have been done previously 71 * with a separate "access_ok()" call (this is used when we do multiple 72 * accesses to the same area of user memory). 73 * 74 * As we use the same address space for kernel and user data on the 75 * PowerPC, we can just do these as direct assignments. (Of course, the 76 * exception handling means that it's no longer "just"...) 77 * 78 */ 79 #define get_user(x, ptr) \ 80 __get_user_check((x), (ptr), sizeof(*(ptr))) 81 #define put_user(x, ptr) \ 82 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 83 84 #define __get_user(x, ptr) \ 85 __get_user_nocheck((x), (ptr), sizeof(*(ptr))) 86 #define __put_user(x, ptr) \ 87 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 88 89 #define __get_user_inatomic(x, ptr) \ 90 __get_user_nosleep((x), (ptr), sizeof(*(ptr))) 91 #define __put_user_inatomic(x, ptr) \ 92 __put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 93 94 extern long __put_user_bad(void); 95 96 /* 97 * We don't tell gcc that we are accessing memory, but this is OK 98 * because we do not write to any memory gcc knows about, so there 99 * are no aliasing issues. 100 */ 101 #define __put_user_asm(x, addr, err, op) \ 102 __asm__ __volatile__( \ 103 "1: " op " %1,0(%2) # put_user\n" \ 104 "2:\n" \ 105 ".section .fixup,\"ax\"\n" \ 106 "3: li %0,%3\n" \ 107 " b 2b\n" \ 108 ".previous\n" \ 109 EX_TABLE(1b, 3b) \ 110 : "=r" (err) \ 111 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) 112 113 #ifdef __powerpc64__ 114 #define __put_user_asm2(x, ptr, retval) \ 115 __put_user_asm(x, ptr, retval, "std") 116 #else /* __powerpc64__ */ 117 #define __put_user_asm2(x, addr, err) \ 118 __asm__ __volatile__( \ 119 "1: stw %1,0(%2)\n" \ 120 "2: stw %1+1,4(%2)\n" \ 121 "3:\n" \ 122 ".section .fixup,\"ax\"\n" \ 123 "4: li %0,%3\n" \ 124 " b 3b\n" \ 125 ".previous\n" \ 126 EX_TABLE(1b, 4b) \ 127 EX_TABLE(2b, 4b) \ 128 : "=r" (err) \ 129 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) 130 #endif /* __powerpc64__ */ 131 132 #define __put_user_size(x, ptr, size, retval) \ 133 do { \ 134 retval = 0; \ 135 switch (size) { \ 136 case 1: __put_user_asm(x, ptr, retval, "stb"); break; \ 137 case 2: __put_user_asm(x, ptr, retval, "sth"); break; \ 138 case 4: __put_user_asm(x, ptr, retval, "stw"); break; \ 139 case 8: __put_user_asm2(x, ptr, retval); break; \ 140 default: __put_user_bad(); \ 141 } \ 142 } while (0) 143 144 #define __put_user_nocheck(x, ptr, size) \ 145 ({ \ 146 long __pu_err; \ 147 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 148 if (!is_kernel_addr((unsigned long)__pu_addr)) \ 149 might_fault(); \ 150 __chk_user_ptr(ptr); \ 151 __put_user_size((x), __pu_addr, (size), __pu_err); \ 152 __pu_err; \ 153 }) 154 155 #define __put_user_check(x, ptr, size) \ 156 ({ \ 157 long __pu_err = -EFAULT; \ 158 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 159 might_fault(); \ 160 if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ 161 __put_user_size((x), __pu_addr, (size), __pu_err); \ 162 __pu_err; \ 163 }) 164 165 #define __put_user_nosleep(x, ptr, size) \ 166 ({ \ 167 long __pu_err; \ 168 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 169 __chk_user_ptr(ptr); \ 170 __put_user_size((x), __pu_addr, (size), __pu_err); \ 171 __pu_err; \ 172 }) 173 174 175 extern long __get_user_bad(void); 176 177 #define __get_user_asm(x, addr, err, op) \ 178 __asm__ __volatile__( \ 179 "1: "op" %1,0(%2) # get_user\n" \ 180 "2:\n" \ 181 ".section .fixup,\"ax\"\n" \ 182 "3: li %0,%3\n" \ 183 " li %1,0\n" \ 184 " b 2b\n" \ 185 ".previous\n" \ 186 EX_TABLE(1b, 3b) \ 187 : "=r" (err), "=r" (x) \ 188 : "b" (addr), "i" (-EFAULT), "0" (err)) 189 190 #ifdef __powerpc64__ 191 #define __get_user_asm2(x, addr, err) \ 192 __get_user_asm(x, addr, err, "ld") 193 #else /* __powerpc64__ */ 194 #define __get_user_asm2(x, addr, err) \ 195 __asm__ __volatile__( \ 196 "1: lwz %1,0(%2)\n" \ 197 "2: lwz %1+1,4(%2)\n" \ 198 "3:\n" \ 199 ".section .fixup,\"ax\"\n" \ 200 "4: li %0,%3\n" \ 201 " li %1,0\n" \ 202 " li %1+1,0\n" \ 203 " b 3b\n" \ 204 ".previous\n" \ 205 EX_TABLE(1b, 4b) \ 206 EX_TABLE(2b, 4b) \ 207 : "=r" (err), "=&r" (x) \ 208 : "b" (addr), "i" (-EFAULT), "0" (err)) 209 #endif /* __powerpc64__ */ 210 211 #define __get_user_size(x, ptr, size, retval) \ 212 do { \ 213 retval = 0; \ 214 __chk_user_ptr(ptr); \ 215 if (size > sizeof(x)) \ 216 (x) = __get_user_bad(); \ 217 switch (size) { \ 218 case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \ 219 case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \ 220 case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \ 221 case 8: __get_user_asm2(x, ptr, retval); break; \ 222 default: (x) = __get_user_bad(); \ 223 } \ 224 } while (0) 225 226 #define __get_user_nocheck(x, ptr, size) \ 227 ({ \ 228 long __gu_err; \ 229 unsigned long __gu_val; \ 230 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 231 __chk_user_ptr(ptr); \ 232 if (!is_kernel_addr((unsigned long)__gu_addr)) \ 233 might_fault(); \ 234 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 235 (x) = (__typeof__(*(ptr)))__gu_val; \ 236 __gu_err; \ 237 }) 238 239 #define __get_user_check(x, ptr, size) \ 240 ({ \ 241 long __gu_err = -EFAULT; \ 242 unsigned long __gu_val = 0; \ 243 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 244 might_fault(); \ 245 if (access_ok(VERIFY_READ, __gu_addr, (size))) \ 246 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 247 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 248 __gu_err; \ 249 }) 250 251 #define __get_user_nosleep(x, ptr, size) \ 252 ({ \ 253 long __gu_err; \ 254 unsigned long __gu_val; \ 255 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 256 __chk_user_ptr(ptr); \ 257 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 258 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 259 __gu_err; \ 260 }) 261 262 263 /* more complex routines */ 264 265 extern unsigned long __copy_tofrom_user(void __user *to, 266 const void __user *from, unsigned long size); 267 268 #ifdef __powerpc64__ 269 static inline unsigned long 270 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) 271 { 272 return __copy_tofrom_user(to, from, n); 273 } 274 #endif /* __powerpc64__ */ 275 276 static inline unsigned long raw_copy_from_user(void *to, 277 const void __user *from, unsigned long n) 278 { 279 if (__builtin_constant_p(n) && (n <= 8)) { 280 unsigned long ret = 1; 281 282 switch (n) { 283 case 1: 284 __get_user_size(*(u8 *)to, from, 1, ret); 285 break; 286 case 2: 287 __get_user_size(*(u16 *)to, from, 2, ret); 288 break; 289 case 4: 290 __get_user_size(*(u32 *)to, from, 4, ret); 291 break; 292 case 8: 293 __get_user_size(*(u64 *)to, from, 8, ret); 294 break; 295 } 296 if (ret == 0) 297 return 0; 298 } 299 300 return __copy_tofrom_user((__force void __user *)to, from, n); 301 } 302 303 static inline unsigned long raw_copy_to_user(void __user *to, 304 const void *from, unsigned long n) 305 { 306 if (__builtin_constant_p(n) && (n <= 8)) { 307 unsigned long ret = 1; 308 309 switch (n) { 310 case 1: 311 __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret); 312 break; 313 case 2: 314 __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret); 315 break; 316 case 4: 317 __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret); 318 break; 319 case 8: 320 __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret); 321 break; 322 } 323 if (ret == 0) 324 return 0; 325 } 326 327 return __copy_tofrom_user(to, (__force const void __user *)from, n); 328 } 329 330 extern unsigned long __clear_user(void __user *addr, unsigned long size); 331 332 static inline unsigned long clear_user(void __user *addr, unsigned long size) 333 { 334 might_fault(); 335 if (likely(access_ok(VERIFY_WRITE, addr, size))) 336 return __clear_user(addr, size); 337 return size; 338 } 339 340 extern long strncpy_from_user(char *dst, const char __user *src, long count); 341 extern __must_check long strnlen_user(const char __user *str, long n); 342 343 #endif /* _ARCH_POWERPC_UACCESS_H */ 344