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 10 /* 11 * The fs value determines whether argument validity checking should be 12 * performed or not. If get_fs() == USER_DS, checking is performed, with 13 * get_fs() == KERNEL_DS, checking is bypassed. 14 * 15 * For historical reasons, these macros are grossly misnamed. 16 * 17 * The fs/ds values are now the highest legal address in the "segment". 18 * This simplifies the checking in the routines below. 19 */ 20 21 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 22 23 #define KERNEL_DS MAKE_MM_SEG(~0UL) 24 #ifdef __powerpc64__ 25 /* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */ 26 #define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1) 27 #else 28 #define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) 29 #endif 30 31 #define get_ds() (KERNEL_DS) 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 switch (size) { \ 145 case 1: __put_user_asm(x, ptr, retval, "stb"); break; \ 146 case 2: __put_user_asm(x, ptr, retval, "sth"); break; \ 147 case 4: __put_user_asm(x, ptr, retval, "stw"); break; \ 148 case 8: __put_user_asm2(x, ptr, retval); break; \ 149 default: __put_user_bad(); \ 150 } \ 151 } while (0) 152 153 #define __put_user_nocheck(x, ptr, size) \ 154 ({ \ 155 long __pu_err; \ 156 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 157 if (!is_kernel_addr((unsigned long)__pu_addr)) \ 158 might_fault(); \ 159 __chk_user_ptr(ptr); \ 160 __put_user_size((x), __pu_addr, (size), __pu_err); \ 161 __pu_err; \ 162 }) 163 164 #define __put_user_check(x, ptr, size) \ 165 ({ \ 166 long __pu_err = -EFAULT; \ 167 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 168 might_fault(); \ 169 if (access_ok(__pu_addr, size)) \ 170 __put_user_size((x), __pu_addr, (size), __pu_err); \ 171 __pu_err; \ 172 }) 173 174 #define __put_user_nosleep(x, ptr, size) \ 175 ({ \ 176 long __pu_err; \ 177 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 178 __chk_user_ptr(ptr); \ 179 __put_user_size((x), __pu_addr, (size), __pu_err); \ 180 __pu_err; \ 181 }) 182 183 184 extern long __get_user_bad(void); 185 186 /* 187 * This does an atomic 128 byte aligned load from userspace. 188 * Upto caller to do enable_kernel_vmx() before calling! 189 */ 190 #define __get_user_atomic_128_aligned(kaddr, uaddr, err) \ 191 __asm__ __volatile__( \ 192 "1: lvx 0,0,%1 # get user\n" \ 193 " stvx 0,0,%2 # put kernel\n" \ 194 "2:\n" \ 195 ".section .fixup,\"ax\"\n" \ 196 "3: li %0,%3\n" \ 197 " b 2b\n" \ 198 ".previous\n" \ 199 EX_TABLE(1b, 3b) \ 200 : "=r" (err) \ 201 : "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "0" (err)) 202 203 #define __get_user_asm(x, addr, err, op) \ 204 __asm__ __volatile__( \ 205 "1: "op" %1,0(%2) # get_user\n" \ 206 "2:\n" \ 207 ".section .fixup,\"ax\"\n" \ 208 "3: li %0,%3\n" \ 209 " li %1,0\n" \ 210 " b 2b\n" \ 211 ".previous\n" \ 212 EX_TABLE(1b, 3b) \ 213 : "=r" (err), "=r" (x) \ 214 : "b" (addr), "i" (-EFAULT), "0" (err)) 215 216 #ifdef __powerpc64__ 217 #define __get_user_asm2(x, addr, err) \ 218 __get_user_asm(x, addr, err, "ld") 219 #else /* __powerpc64__ */ 220 #define __get_user_asm2(x, addr, err) \ 221 __asm__ __volatile__( \ 222 "1: lwz %1,0(%2)\n" \ 223 "2: lwz %1+1,4(%2)\n" \ 224 "3:\n" \ 225 ".section .fixup,\"ax\"\n" \ 226 "4: li %0,%3\n" \ 227 " li %1,0\n" \ 228 " li %1+1,0\n" \ 229 " b 3b\n" \ 230 ".previous\n" \ 231 EX_TABLE(1b, 4b) \ 232 EX_TABLE(2b, 4b) \ 233 : "=r" (err), "=&r" (x) \ 234 : "b" (addr), "i" (-EFAULT), "0" (err)) 235 #endif /* __powerpc64__ */ 236 237 #define __get_user_size(x, ptr, size, retval) \ 238 do { \ 239 retval = 0; \ 240 __chk_user_ptr(ptr); \ 241 if (size > sizeof(x)) \ 242 (x) = __get_user_bad(); \ 243 switch (size) { \ 244 case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \ 245 case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \ 246 case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \ 247 case 8: __get_user_asm2(x, ptr, retval); break; \ 248 default: (x) = __get_user_bad(); \ 249 } \ 250 } while (0) 251 252 /* 253 * This is a type: either unsigned long, if the argument fits into 254 * that type, or otherwise unsigned long long. 255 */ 256 #define __long_type(x) \ 257 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) 258 259 #define __get_user_nocheck(x, ptr, size) \ 260 ({ \ 261 long __gu_err; \ 262 __long_type(*(ptr)) __gu_val; \ 263 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 264 __chk_user_ptr(ptr); \ 265 if (!is_kernel_addr((unsigned long)__gu_addr)) \ 266 might_fault(); \ 267 barrier_nospec(); \ 268 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 269 (x) = (__typeof__(*(ptr)))__gu_val; \ 270 __gu_err; \ 271 }) 272 273 #define __get_user_check(x, ptr, size) \ 274 ({ \ 275 long __gu_err = -EFAULT; \ 276 __long_type(*(ptr)) __gu_val = 0; \ 277 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 278 might_fault(); \ 279 if (access_ok(__gu_addr, (size))) { \ 280 barrier_nospec(); \ 281 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 282 } \ 283 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 284 __gu_err; \ 285 }) 286 287 #define __get_user_nosleep(x, ptr, size) \ 288 ({ \ 289 long __gu_err; \ 290 __long_type(*(ptr)) __gu_val; \ 291 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 292 __chk_user_ptr(ptr); \ 293 barrier_nospec(); \ 294 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 295 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 296 __gu_err; \ 297 }) 298 299 300 /* more complex routines */ 301 302 extern unsigned long __copy_tofrom_user(void __user *to, 303 const void __user *from, unsigned long size); 304 305 #ifdef __powerpc64__ 306 static inline unsigned long 307 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) 308 { 309 return __copy_tofrom_user(to, from, n); 310 } 311 #endif /* __powerpc64__ */ 312 313 static inline unsigned long raw_copy_from_user(void *to, 314 const void __user *from, unsigned long n) 315 { 316 if (__builtin_constant_p(n) && (n <= 8)) { 317 unsigned long ret = 1; 318 319 switch (n) { 320 case 1: 321 barrier_nospec(); 322 __get_user_size(*(u8 *)to, from, 1, ret); 323 break; 324 case 2: 325 barrier_nospec(); 326 __get_user_size(*(u16 *)to, from, 2, ret); 327 break; 328 case 4: 329 barrier_nospec(); 330 __get_user_size(*(u32 *)to, from, 4, ret); 331 break; 332 case 8: 333 barrier_nospec(); 334 __get_user_size(*(u64 *)to, from, 8, ret); 335 break; 336 } 337 if (ret == 0) 338 return 0; 339 } 340 341 barrier_nospec(); 342 return __copy_tofrom_user((__force void __user *)to, from, n); 343 } 344 345 static inline unsigned long raw_copy_to_user(void __user *to, 346 const void *from, unsigned long n) 347 { 348 if (__builtin_constant_p(n) && (n <= 8)) { 349 unsigned long ret = 1; 350 351 switch (n) { 352 case 1: 353 __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret); 354 break; 355 case 2: 356 __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret); 357 break; 358 case 4: 359 __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret); 360 break; 361 case 8: 362 __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret); 363 break; 364 } 365 if (ret == 0) 366 return 0; 367 } 368 369 return __copy_tofrom_user(to, (__force const void __user *)from, n); 370 } 371 372 extern unsigned long __clear_user(void __user *addr, unsigned long size); 373 374 static inline unsigned long clear_user(void __user *addr, unsigned long size) 375 { 376 might_fault(); 377 if (likely(access_ok(addr, size))) 378 return __clear_user(addr, size); 379 return size; 380 } 381 382 extern long strncpy_from_user(char *dst, const char __user *src, long count); 383 extern __must_check long strnlen_user(const char __user *str, long n); 384 385 extern long __copy_from_user_flushcache(void *dst, const void __user *src, 386 unsigned size); 387 extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset, 388 size_t len); 389 390 #endif /* _ARCH_POWERPC_UACCESS_H */ 391