1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ARCH_POWERPC_UACCESS_H 3 #define _ARCH_POWERPC_UACCESS_H 4 5 #include <asm/ppc_asm.h> 6 #include <asm/processor.h> 7 #include <asm/page.h> 8 #include <asm/extable.h> 9 #include <asm/kup.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_fs() (current->thread.addr_limit) 33 34 static inline void set_fs(mm_segment_t fs) 35 { 36 current->thread.addr_limit = fs; 37 /* On user-mode return check addr_limit (fs) is correct */ 38 set_thread_flag(TIF_FSCHECK); 39 } 40 41 #define segment_eq(a, b) ((a).seg == (b).seg) 42 43 #define user_addr_max() (get_fs().seg) 44 45 #ifdef __powerpc64__ 46 /* 47 * This check is sufficient because there is a large enough 48 * gap between user addresses and the kernel addresses 49 */ 50 #define __access_ok(addr, size, segment) \ 51 (((addr) <= (segment).seg) && ((size) <= (segment).seg)) 52 53 #else 54 55 static inline int __access_ok(unsigned long addr, unsigned long size, 56 mm_segment_t seg) 57 { 58 if (addr > seg.seg) 59 return 0; 60 return (size == 0 || size - 1 <= seg.seg - addr); 61 } 62 63 #endif 64 65 #define access_ok(addr, size) \ 66 (__chk_user_ptr(addr), \ 67 __access_ok((__force unsigned long)(addr), (size), get_fs())) 68 69 /* 70 * These are the main single-value transfer routines. They automatically 71 * use the right size if we just have the right pointer type. 72 * 73 * This gets kind of ugly. We want to return _two_ values in "get_user()" 74 * and yet we don't want to do any pointers, because that is too much 75 * of a performance impact. Thus we have a few rather ugly macros here, 76 * and hide all the ugliness from the user. 77 * 78 * The "__xxx" versions of the user access functions are versions that 79 * do not verify the address space, that must have been done previously 80 * with a separate "access_ok()" call (this is used when we do multiple 81 * accesses to the same area of user memory). 82 * 83 * As we use the same address space for kernel and user data on the 84 * PowerPC, we can just do these as direct assignments. (Of course, the 85 * exception handling means that it's no longer "just"...) 86 * 87 */ 88 #define get_user(x, ptr) \ 89 __get_user_check((x), (ptr), sizeof(*(ptr))) 90 #define put_user(x, ptr) \ 91 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 92 93 #define __get_user(x, ptr) \ 94 __get_user_nocheck((x), (ptr), sizeof(*(ptr))) 95 #define __put_user(x, ptr) \ 96 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 97 98 #define __get_user_inatomic(x, ptr) \ 99 __get_user_nosleep((x), (ptr), sizeof(*(ptr))) 100 #define __put_user_inatomic(x, ptr) \ 101 __put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 102 103 extern long __put_user_bad(void); 104 105 /* 106 * We don't tell gcc that we are accessing memory, but this is OK 107 * because we do not write to any memory gcc knows about, so there 108 * are no aliasing issues. 109 */ 110 #define __put_user_asm(x, addr, err, op) \ 111 __asm__ __volatile__( \ 112 "1: " op " %1,0(%2) # put_user\n" \ 113 "2:\n" \ 114 ".section .fixup,\"ax\"\n" \ 115 "3: li %0,%3\n" \ 116 " b 2b\n" \ 117 ".previous\n" \ 118 EX_TABLE(1b, 3b) \ 119 : "=r" (err) \ 120 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) 121 122 #ifdef __powerpc64__ 123 #define __put_user_asm2(x, ptr, retval) \ 124 __put_user_asm(x, ptr, retval, "std") 125 #else /* __powerpc64__ */ 126 #define __put_user_asm2(x, addr, err) \ 127 __asm__ __volatile__( \ 128 "1: stw %1,0(%2)\n" \ 129 "2: stw %1+1,4(%2)\n" \ 130 "3:\n" \ 131 ".section .fixup,\"ax\"\n" \ 132 "4: li %0,%3\n" \ 133 " b 3b\n" \ 134 ".previous\n" \ 135 EX_TABLE(1b, 4b) \ 136 EX_TABLE(2b, 4b) \ 137 : "=r" (err) \ 138 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) 139 #endif /* __powerpc64__ */ 140 141 #define __put_user_size(x, ptr, size, retval) \ 142 do { \ 143 retval = 0; \ 144 allow_write_to_user(ptr, size); \ 145 switch (size) { \ 146 case 1: __put_user_asm(x, ptr, retval, "stb"); break; \ 147 case 2: __put_user_asm(x, ptr, retval, "sth"); break; \ 148 case 4: __put_user_asm(x, ptr, retval, "stw"); break; \ 149 case 8: __put_user_asm2(x, ptr, retval); break; \ 150 default: __put_user_bad(); \ 151 } \ 152 prevent_write_to_user(ptr, size); \ 153 } while (0) 154 155 #define __put_user_nocheck(x, ptr, size) \ 156 ({ \ 157 long __pu_err; \ 158 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 159 if (!is_kernel_addr((unsigned long)__pu_addr)) \ 160 might_fault(); \ 161 __chk_user_ptr(ptr); \ 162 __put_user_size((x), __pu_addr, (size), __pu_err); \ 163 __pu_err; \ 164 }) 165 166 #define __put_user_check(x, ptr, size) \ 167 ({ \ 168 long __pu_err = -EFAULT; \ 169 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 170 might_fault(); \ 171 if (access_ok(__pu_addr, size)) \ 172 __put_user_size((x), __pu_addr, (size), __pu_err); \ 173 __pu_err; \ 174 }) 175 176 #define __put_user_nosleep(x, ptr, size) \ 177 ({ \ 178 long __pu_err; \ 179 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 180 __chk_user_ptr(ptr); \ 181 __put_user_size((x), __pu_addr, (size), __pu_err); \ 182 __pu_err; \ 183 }) 184 185 186 extern long __get_user_bad(void); 187 188 /* 189 * This does an atomic 128 byte aligned load from userspace. 190 * Upto caller to do enable_kernel_vmx() before calling! 191 */ 192 #define __get_user_atomic_128_aligned(kaddr, uaddr, err) \ 193 __asm__ __volatile__( \ 194 "1: lvx 0,0,%1 # get user\n" \ 195 " stvx 0,0,%2 # put kernel\n" \ 196 "2:\n" \ 197 ".section .fixup,\"ax\"\n" \ 198 "3: li %0,%3\n" \ 199 " b 2b\n" \ 200 ".previous\n" \ 201 EX_TABLE(1b, 3b) \ 202 : "=r" (err) \ 203 : "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "0" (err)) 204 205 #define __get_user_asm(x, addr, err, op) \ 206 __asm__ __volatile__( \ 207 "1: "op" %1,0(%2) # get_user\n" \ 208 "2:\n" \ 209 ".section .fixup,\"ax\"\n" \ 210 "3: li %0,%3\n" \ 211 " li %1,0\n" \ 212 " b 2b\n" \ 213 ".previous\n" \ 214 EX_TABLE(1b, 3b) \ 215 : "=r" (err), "=r" (x) \ 216 : "b" (addr), "i" (-EFAULT), "0" (err)) 217 218 #ifdef __powerpc64__ 219 #define __get_user_asm2(x, addr, err) \ 220 __get_user_asm(x, addr, err, "ld") 221 #else /* __powerpc64__ */ 222 #define __get_user_asm2(x, addr, err) \ 223 __asm__ __volatile__( \ 224 "1: lwz %1,0(%2)\n" \ 225 "2: lwz %1+1,4(%2)\n" \ 226 "3:\n" \ 227 ".section .fixup,\"ax\"\n" \ 228 "4: li %0,%3\n" \ 229 " li %1,0\n" \ 230 " li %1+1,0\n" \ 231 " b 3b\n" \ 232 ".previous\n" \ 233 EX_TABLE(1b, 4b) \ 234 EX_TABLE(2b, 4b) \ 235 : "=r" (err), "=&r" (x) \ 236 : "b" (addr), "i" (-EFAULT), "0" (err)) 237 #endif /* __powerpc64__ */ 238 239 #define __get_user_size(x, ptr, size, retval) \ 240 do { \ 241 retval = 0; \ 242 __chk_user_ptr(ptr); \ 243 if (size > sizeof(x)) \ 244 (x) = __get_user_bad(); \ 245 allow_read_from_user(ptr, size); \ 246 switch (size) { \ 247 case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \ 248 case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \ 249 case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \ 250 case 8: __get_user_asm2(x, ptr, retval); break; \ 251 default: (x) = __get_user_bad(); \ 252 } \ 253 prevent_read_from_user(ptr, size); \ 254 } while (0) 255 256 /* 257 * This is a type: either unsigned long, if the argument fits into 258 * that type, or otherwise unsigned long long. 259 */ 260 #define __long_type(x) \ 261 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) 262 263 #define __get_user_nocheck(x, ptr, size) \ 264 ({ \ 265 long __gu_err; \ 266 __long_type(*(ptr)) __gu_val; \ 267 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 268 __chk_user_ptr(ptr); \ 269 if (!is_kernel_addr((unsigned long)__gu_addr)) \ 270 might_fault(); \ 271 barrier_nospec(); \ 272 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 273 (x) = (__typeof__(*(ptr)))__gu_val; \ 274 __gu_err; \ 275 }) 276 277 #define __get_user_check(x, ptr, size) \ 278 ({ \ 279 long __gu_err = -EFAULT; \ 280 __long_type(*(ptr)) __gu_val = 0; \ 281 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 282 might_fault(); \ 283 if (access_ok(__gu_addr, (size))) { \ 284 barrier_nospec(); \ 285 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 286 } \ 287 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 288 __gu_err; \ 289 }) 290 291 #define __get_user_nosleep(x, ptr, size) \ 292 ({ \ 293 long __gu_err; \ 294 __long_type(*(ptr)) __gu_val; \ 295 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 296 __chk_user_ptr(ptr); \ 297 barrier_nospec(); \ 298 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 299 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 300 __gu_err; \ 301 }) 302 303 304 /* more complex routines */ 305 306 extern unsigned long __copy_tofrom_user(void __user *to, 307 const void __user *from, unsigned long size); 308 309 #ifdef __powerpc64__ 310 static inline unsigned long 311 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) 312 { 313 unsigned long ret; 314 315 barrier_nospec(); 316 allow_user_access(to, from, n); 317 ret = __copy_tofrom_user(to, from, n); 318 prevent_user_access(to, from, n); 319 return ret; 320 } 321 #endif /* __powerpc64__ */ 322 323 static inline unsigned long raw_copy_from_user(void *to, 324 const void __user *from, unsigned long n) 325 { 326 unsigned long ret; 327 if (__builtin_constant_p(n) && (n <= 8)) { 328 ret = 1; 329 330 switch (n) { 331 case 1: 332 barrier_nospec(); 333 __get_user_size(*(u8 *)to, from, 1, ret); 334 break; 335 case 2: 336 barrier_nospec(); 337 __get_user_size(*(u16 *)to, from, 2, ret); 338 break; 339 case 4: 340 barrier_nospec(); 341 __get_user_size(*(u32 *)to, from, 4, ret); 342 break; 343 case 8: 344 barrier_nospec(); 345 __get_user_size(*(u64 *)to, from, 8, ret); 346 break; 347 } 348 if (ret == 0) 349 return 0; 350 } 351 352 barrier_nospec(); 353 allow_read_from_user(from, n); 354 ret = __copy_tofrom_user((__force void __user *)to, from, n); 355 prevent_read_from_user(from, n); 356 return ret; 357 } 358 359 static inline unsigned long raw_copy_to_user(void __user *to, 360 const void *from, unsigned long n) 361 { 362 unsigned long ret; 363 if (__builtin_constant_p(n) && (n <= 8)) { 364 ret = 1; 365 366 switch (n) { 367 case 1: 368 __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret); 369 break; 370 case 2: 371 __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret); 372 break; 373 case 4: 374 __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret); 375 break; 376 case 8: 377 __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret); 378 break; 379 } 380 if (ret == 0) 381 return 0; 382 } 383 384 allow_write_to_user(to, n); 385 ret = __copy_tofrom_user(to, (__force const void __user *)from, n); 386 prevent_write_to_user(to, n); 387 return ret; 388 } 389 390 extern unsigned long __clear_user(void __user *addr, unsigned long size); 391 392 static inline unsigned long clear_user(void __user *addr, unsigned long size) 393 { 394 unsigned long ret = size; 395 might_fault(); 396 if (likely(access_ok(addr, size))) { 397 allow_write_to_user(addr, size); 398 ret = __clear_user(addr, size); 399 prevent_write_to_user(addr, size); 400 } 401 return ret; 402 } 403 404 extern long strncpy_from_user(char *dst, const char __user *src, long count); 405 extern __must_check long strnlen_user(const char __user *str, long n); 406 407 extern long __copy_from_user_flushcache(void *dst, const void __user *src, 408 unsigned size); 409 extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset, 410 size_t len); 411 412 #endif /* _ARCH_POWERPC_UACCESS_H */ 413