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_fs() (current->thread.addr_limit) 32 33 static inline void set_fs(mm_segment_t fs) 34 { 35 current->thread.addr_limit = fs; 36 /* On user-mode return check addr_limit (fs) is correct */ 37 set_thread_flag(TIF_FSCHECK); 38 } 39 40 #define segment_eq(a, b) ((a).seg == (b).seg) 41 42 #define user_addr_max() (get_fs().seg) 43 44 #ifdef __powerpc64__ 45 /* 46 * This check is sufficient because there is a large enough 47 * gap between user addresses and the kernel addresses 48 */ 49 #define __access_ok(addr, size, segment) \ 50 (((addr) <= (segment).seg) && ((size) <= (segment).seg)) 51 52 #else 53 54 static inline int __access_ok(unsigned long addr, unsigned long size, 55 mm_segment_t seg) 56 { 57 if (addr > seg.seg) 58 return 0; 59 return (size == 0 || size - 1 <= seg.seg - addr); 60 } 61 62 #endif 63 64 #define access_ok(addr, size) \ 65 (__chk_user_ptr(addr), \ 66 __access_ok((__force unsigned long)(addr), (size), get_fs())) 67 68 /* 69 * These are the main single-value transfer routines. They automatically 70 * use the right size if we just have the right pointer type. 71 * 72 * This gets kind of ugly. We want to return _two_ values in "get_user()" 73 * and yet we don't want to do any pointers, because that is too much 74 * of a performance impact. Thus we have a few rather ugly macros here, 75 * and hide all the ugliness from the user. 76 * 77 * The "__xxx" versions of the user access functions are versions that 78 * do not verify the address space, that must have been done previously 79 * with a separate "access_ok()" call (this is used when we do multiple 80 * accesses to the same area of user memory). 81 * 82 * As we use the same address space for kernel and user data on the 83 * PowerPC, we can just do these as direct assignments. (Of course, the 84 * exception handling means that it's no longer "just"...) 85 * 86 */ 87 #define get_user(x, ptr) \ 88 __get_user_check((x), (ptr), sizeof(*(ptr))) 89 #define put_user(x, ptr) \ 90 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 91 92 #define __get_user(x, ptr) \ 93 __get_user_nocheck((x), (ptr), sizeof(*(ptr))) 94 #define __put_user(x, ptr) \ 95 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 96 97 #define __get_user_inatomic(x, ptr) \ 98 __get_user_nosleep((x), (ptr), sizeof(*(ptr))) 99 #define __put_user_inatomic(x, ptr) \ 100 __put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 101 102 extern long __put_user_bad(void); 103 104 /* 105 * We don't tell gcc that we are accessing memory, but this is OK 106 * because we do not write to any memory gcc knows about, so there 107 * are no aliasing issues. 108 */ 109 #define __put_user_asm(x, addr, err, op) \ 110 __asm__ __volatile__( \ 111 "1: " op " %1,0(%2) # put_user\n" \ 112 "2:\n" \ 113 ".section .fixup,\"ax\"\n" \ 114 "3: li %0,%3\n" \ 115 " b 2b\n" \ 116 ".previous\n" \ 117 EX_TABLE(1b, 3b) \ 118 : "=r" (err) \ 119 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) 120 121 #ifdef __powerpc64__ 122 #define __put_user_asm2(x, ptr, retval) \ 123 __put_user_asm(x, ptr, retval, "std") 124 #else /* __powerpc64__ */ 125 #define __put_user_asm2(x, addr, err) \ 126 __asm__ __volatile__( \ 127 "1: stw %1,0(%2)\n" \ 128 "2: stw %1+1,4(%2)\n" \ 129 "3:\n" \ 130 ".section .fixup,\"ax\"\n" \ 131 "4: li %0,%3\n" \ 132 " b 3b\n" \ 133 ".previous\n" \ 134 EX_TABLE(1b, 4b) \ 135 EX_TABLE(2b, 4b) \ 136 : "=r" (err) \ 137 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) 138 #endif /* __powerpc64__ */ 139 140 #define __put_user_size(x, ptr, size, retval) \ 141 do { \ 142 retval = 0; \ 143 switch (size) { \ 144 case 1: __put_user_asm(x, ptr, retval, "stb"); break; \ 145 case 2: __put_user_asm(x, ptr, retval, "sth"); break; \ 146 case 4: __put_user_asm(x, ptr, retval, "stw"); break; \ 147 case 8: __put_user_asm2(x, ptr, retval); break; \ 148 default: __put_user_bad(); \ 149 } \ 150 } while (0) 151 152 #define __put_user_nocheck(x, ptr, size) \ 153 ({ \ 154 long __pu_err; \ 155 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 156 if (!is_kernel_addr((unsigned long)__pu_addr)) \ 157 might_fault(); \ 158 __chk_user_ptr(ptr); \ 159 __put_user_size((x), __pu_addr, (size), __pu_err); \ 160 __pu_err; \ 161 }) 162 163 #define __put_user_check(x, ptr, size) \ 164 ({ \ 165 long __pu_err = -EFAULT; \ 166 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 167 might_fault(); \ 168 if (access_ok(__pu_addr, size)) \ 169 __put_user_size((x), __pu_addr, (size), __pu_err); \ 170 __pu_err; \ 171 }) 172 173 #define __put_user_nosleep(x, ptr, size) \ 174 ({ \ 175 long __pu_err; \ 176 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 177 __chk_user_ptr(ptr); \ 178 __put_user_size((x), __pu_addr, (size), __pu_err); \ 179 __pu_err; \ 180 }) 181 182 183 extern long __get_user_bad(void); 184 185 /* 186 * This does an atomic 128 byte aligned load from userspace. 187 * Upto caller to do enable_kernel_vmx() before calling! 188 */ 189 #define __get_user_atomic_128_aligned(kaddr, uaddr, err) \ 190 __asm__ __volatile__( \ 191 "1: lvx 0,0,%1 # get user\n" \ 192 " stvx 0,0,%2 # put kernel\n" \ 193 "2:\n" \ 194 ".section .fixup,\"ax\"\n" \ 195 "3: li %0,%3\n" \ 196 " b 2b\n" \ 197 ".previous\n" \ 198 EX_TABLE(1b, 3b) \ 199 : "=r" (err) \ 200 : "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "0" (err)) 201 202 #define __get_user_asm(x, addr, err, op) \ 203 __asm__ __volatile__( \ 204 "1: "op" %1,0(%2) # get_user\n" \ 205 "2:\n" \ 206 ".section .fixup,\"ax\"\n" \ 207 "3: li %0,%3\n" \ 208 " li %1,0\n" \ 209 " b 2b\n" \ 210 ".previous\n" \ 211 EX_TABLE(1b, 3b) \ 212 : "=r" (err), "=r" (x) \ 213 : "b" (addr), "i" (-EFAULT), "0" (err)) 214 215 #ifdef __powerpc64__ 216 #define __get_user_asm2(x, addr, err) \ 217 __get_user_asm(x, addr, err, "ld") 218 #else /* __powerpc64__ */ 219 #define __get_user_asm2(x, addr, err) \ 220 __asm__ __volatile__( \ 221 "1: lwz %1,0(%2)\n" \ 222 "2: lwz %1+1,4(%2)\n" \ 223 "3:\n" \ 224 ".section .fixup,\"ax\"\n" \ 225 "4: li %0,%3\n" \ 226 " li %1,0\n" \ 227 " li %1+1,0\n" \ 228 " b 3b\n" \ 229 ".previous\n" \ 230 EX_TABLE(1b, 4b) \ 231 EX_TABLE(2b, 4b) \ 232 : "=r" (err), "=&r" (x) \ 233 : "b" (addr), "i" (-EFAULT), "0" (err)) 234 #endif /* __powerpc64__ */ 235 236 #define __get_user_size(x, ptr, size, retval) \ 237 do { \ 238 retval = 0; \ 239 __chk_user_ptr(ptr); \ 240 if (size > sizeof(x)) \ 241 (x) = __get_user_bad(); \ 242 switch (size) { \ 243 case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \ 244 case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \ 245 case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \ 246 case 8: __get_user_asm2(x, ptr, retval); break; \ 247 default: (x) = __get_user_bad(); \ 248 } \ 249 } while (0) 250 251 /* 252 * This is a type: either unsigned long, if the argument fits into 253 * that type, or otherwise unsigned long long. 254 */ 255 #define __long_type(x) \ 256 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) 257 258 #define __get_user_nocheck(x, ptr, size) \ 259 ({ \ 260 long __gu_err; \ 261 __long_type(*(ptr)) __gu_val; \ 262 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 263 __chk_user_ptr(ptr); \ 264 if (!is_kernel_addr((unsigned long)__gu_addr)) \ 265 might_fault(); \ 266 barrier_nospec(); \ 267 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 268 (x) = (__typeof__(*(ptr)))__gu_val; \ 269 __gu_err; \ 270 }) 271 272 #define __get_user_check(x, ptr, size) \ 273 ({ \ 274 long __gu_err = -EFAULT; \ 275 __long_type(*(ptr)) __gu_val = 0; \ 276 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 277 might_fault(); \ 278 if (access_ok(__gu_addr, (size))) { \ 279 barrier_nospec(); \ 280 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 281 } \ 282 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 283 __gu_err; \ 284 }) 285 286 #define __get_user_nosleep(x, ptr, size) \ 287 ({ \ 288 long __gu_err; \ 289 __long_type(*(ptr)) __gu_val; \ 290 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 291 __chk_user_ptr(ptr); \ 292 barrier_nospec(); \ 293 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 294 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 295 __gu_err; \ 296 }) 297 298 299 /* more complex routines */ 300 301 extern unsigned long __copy_tofrom_user(void __user *to, 302 const void __user *from, unsigned long size); 303 304 #ifdef __powerpc64__ 305 static inline unsigned long 306 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) 307 { 308 return __copy_tofrom_user(to, from, n); 309 } 310 #endif /* __powerpc64__ */ 311 312 static inline unsigned long raw_copy_from_user(void *to, 313 const void __user *from, unsigned long n) 314 { 315 if (__builtin_constant_p(n) && (n <= 8)) { 316 unsigned long ret = 1; 317 318 switch (n) { 319 case 1: 320 barrier_nospec(); 321 __get_user_size(*(u8 *)to, from, 1, ret); 322 break; 323 case 2: 324 barrier_nospec(); 325 __get_user_size(*(u16 *)to, from, 2, ret); 326 break; 327 case 4: 328 barrier_nospec(); 329 __get_user_size(*(u32 *)to, from, 4, ret); 330 break; 331 case 8: 332 barrier_nospec(); 333 __get_user_size(*(u64 *)to, from, 8, ret); 334 break; 335 } 336 if (ret == 0) 337 return 0; 338 } 339 340 barrier_nospec(); 341 return __copy_tofrom_user((__force void __user *)to, from, n); 342 } 343 344 static inline unsigned long raw_copy_to_user(void __user *to, 345 const void *from, unsigned long n) 346 { 347 if (__builtin_constant_p(n) && (n <= 8)) { 348 unsigned long ret = 1; 349 350 switch (n) { 351 case 1: 352 __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret); 353 break; 354 case 2: 355 __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret); 356 break; 357 case 4: 358 __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret); 359 break; 360 case 8: 361 __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret); 362 break; 363 } 364 if (ret == 0) 365 return 0; 366 } 367 368 return __copy_tofrom_user(to, (__force const void __user *)from, n); 369 } 370 371 extern unsigned long __clear_user(void __user *addr, unsigned long size); 372 373 static inline unsigned long clear_user(void __user *addr, unsigned long size) 374 { 375 might_fault(); 376 if (likely(access_ok(addr, size))) 377 return __clear_user(addr, size); 378 return size; 379 } 380 381 extern long strncpy_from_user(char *dst, const char __user *src, long count); 382 extern __must_check long strnlen_user(const char __user *str, long n); 383 384 extern long __copy_from_user_flushcache(void *dst, const void __user *src, 385 unsigned size); 386 extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset, 387 size_t len); 388 389 #endif /* _ARCH_POWERPC_UACCESS_H */ 390