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 static inline int __access_ok(unsigned long addr, unsigned long size, 51 mm_segment_t seg) 52 { 53 if (addr > seg.seg) 54 return 0; 55 return (size == 0 || size - 1 <= seg.seg - addr); 56 } 57 58 #endif 59 60 #define access_ok(type, addr, size) \ 61 (__chk_user_ptr(addr), \ 62 __access_ok((__force unsigned long)(addr), (size), get_fs())) 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 ugliness 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 */ 83 #define get_user(x, ptr) \ 84 __get_user_check((x), (ptr), sizeof(*(ptr))) 85 #define put_user(x, ptr) \ 86 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 87 88 #define __get_user(x, ptr) \ 89 __get_user_nocheck((x), (ptr), sizeof(*(ptr))) 90 #define __put_user(x, ptr) \ 91 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 92 93 #define __get_user_inatomic(x, ptr) \ 94 __get_user_nosleep((x), (ptr), sizeof(*(ptr))) 95 #define __put_user_inatomic(x, ptr) \ 96 __put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 97 98 extern long __put_user_bad(void); 99 100 /* 101 * We don't tell gcc that we are accessing memory, but this is OK 102 * because we do not write to any memory gcc knows about, so there 103 * are no aliasing issues. 104 */ 105 #define __put_user_asm(x, addr, err, op) \ 106 __asm__ __volatile__( \ 107 "1: " op " %1,0(%2) # put_user\n" \ 108 "2:\n" \ 109 ".section .fixup,\"ax\"\n" \ 110 "3: li %0,%3\n" \ 111 " b 2b\n" \ 112 ".previous\n" \ 113 EX_TABLE(1b, 3b) \ 114 : "=r" (err) \ 115 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) 116 117 #ifdef __powerpc64__ 118 #define __put_user_asm2(x, ptr, retval) \ 119 __put_user_asm(x, ptr, retval, "std") 120 #else /* __powerpc64__ */ 121 #define __put_user_asm2(x, addr, err) \ 122 __asm__ __volatile__( \ 123 "1: stw %1,0(%2)\n" \ 124 "2: stw %1+1,4(%2)\n" \ 125 "3:\n" \ 126 ".section .fixup,\"ax\"\n" \ 127 "4: li %0,%3\n" \ 128 " b 3b\n" \ 129 ".previous\n" \ 130 EX_TABLE(1b, 4b) \ 131 EX_TABLE(2b, 4b) \ 132 : "=r" (err) \ 133 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) 134 #endif /* __powerpc64__ */ 135 136 #define __put_user_size(x, ptr, size, retval) \ 137 do { \ 138 retval = 0; \ 139 switch (size) { \ 140 case 1: __put_user_asm(x, ptr, retval, "stb"); break; \ 141 case 2: __put_user_asm(x, ptr, retval, "sth"); break; \ 142 case 4: __put_user_asm(x, ptr, retval, "stw"); break; \ 143 case 8: __put_user_asm2(x, ptr, retval); break; \ 144 default: __put_user_bad(); \ 145 } \ 146 } while (0) 147 148 #define __put_user_nocheck(x, ptr, size) \ 149 ({ \ 150 long __pu_err; \ 151 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 152 if (!is_kernel_addr((unsigned long)__pu_addr)) \ 153 might_fault(); \ 154 __chk_user_ptr(ptr); \ 155 __put_user_size((x), __pu_addr, (size), __pu_err); \ 156 __pu_err; \ 157 }) 158 159 #define __put_user_check(x, ptr, size) \ 160 ({ \ 161 long __pu_err = -EFAULT; \ 162 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 163 might_fault(); \ 164 if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ 165 __put_user_size((x), __pu_addr, (size), __pu_err); \ 166 __pu_err; \ 167 }) 168 169 #define __put_user_nosleep(x, ptr, size) \ 170 ({ \ 171 long __pu_err; \ 172 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 173 __chk_user_ptr(ptr); \ 174 __put_user_size((x), __pu_addr, (size), __pu_err); \ 175 __pu_err; \ 176 }) 177 178 179 extern long __get_user_bad(void); 180 181 /* 182 * This does an atomic 128 byte aligned load from userspace. 183 * Upto caller to do enable_kernel_vmx() before calling! 184 */ 185 #define __get_user_atomic_128_aligned(kaddr, uaddr, err) \ 186 __asm__ __volatile__( \ 187 "1: lvx 0,0,%1 # get user\n" \ 188 " stvx 0,0,%2 # put kernel\n" \ 189 "2:\n" \ 190 ".section .fixup,\"ax\"\n" \ 191 "3: li %0,%3\n" \ 192 " b 2b\n" \ 193 ".previous\n" \ 194 EX_TABLE(1b, 3b) \ 195 : "=r" (err) \ 196 : "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "0" (err)) 197 198 #define __get_user_asm(x, addr, err, op) \ 199 __asm__ __volatile__( \ 200 "1: "op" %1,0(%2) # get_user\n" \ 201 "2:\n" \ 202 ".section .fixup,\"ax\"\n" \ 203 "3: li %0,%3\n" \ 204 " li %1,0\n" \ 205 " b 2b\n" \ 206 ".previous\n" \ 207 EX_TABLE(1b, 3b) \ 208 : "=r" (err), "=r" (x) \ 209 : "b" (addr), "i" (-EFAULT), "0" (err)) 210 211 #ifdef __powerpc64__ 212 #define __get_user_asm2(x, addr, err) \ 213 __get_user_asm(x, addr, err, "ld") 214 #else /* __powerpc64__ */ 215 #define __get_user_asm2(x, addr, err) \ 216 __asm__ __volatile__( \ 217 "1: lwz %1,0(%2)\n" \ 218 "2: lwz %1+1,4(%2)\n" \ 219 "3:\n" \ 220 ".section .fixup,\"ax\"\n" \ 221 "4: li %0,%3\n" \ 222 " li %1,0\n" \ 223 " li %1+1,0\n" \ 224 " b 3b\n" \ 225 ".previous\n" \ 226 EX_TABLE(1b, 4b) \ 227 EX_TABLE(2b, 4b) \ 228 : "=r" (err), "=&r" (x) \ 229 : "b" (addr), "i" (-EFAULT), "0" (err)) 230 #endif /* __powerpc64__ */ 231 232 #define __get_user_size(x, ptr, size, retval) \ 233 do { \ 234 retval = 0; \ 235 __chk_user_ptr(ptr); \ 236 if (size > sizeof(x)) \ 237 (x) = __get_user_bad(); \ 238 switch (size) { \ 239 case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \ 240 case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \ 241 case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \ 242 case 8: __get_user_asm2(x, ptr, retval); break; \ 243 default: (x) = __get_user_bad(); \ 244 } \ 245 } while (0) 246 247 #define __get_user_nocheck(x, ptr, size) \ 248 ({ \ 249 long __gu_err; \ 250 unsigned long __gu_val; \ 251 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 252 __chk_user_ptr(ptr); \ 253 if (!is_kernel_addr((unsigned long)__gu_addr)) \ 254 might_fault(); \ 255 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 256 (x) = (__typeof__(*(ptr)))__gu_val; \ 257 __gu_err; \ 258 }) 259 260 #define __get_user_check(x, ptr, size) \ 261 ({ \ 262 long __gu_err = -EFAULT; \ 263 unsigned long __gu_val = 0; \ 264 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 265 might_fault(); \ 266 if (access_ok(VERIFY_READ, __gu_addr, (size))) \ 267 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 268 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 269 __gu_err; \ 270 }) 271 272 #define __get_user_nosleep(x, ptr, size) \ 273 ({ \ 274 long __gu_err; \ 275 unsigned long __gu_val; \ 276 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 277 __chk_user_ptr(ptr); \ 278 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 279 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 280 __gu_err; \ 281 }) 282 283 284 /* more complex routines */ 285 286 extern unsigned long __copy_tofrom_user(void __user *to, 287 const void __user *from, unsigned long size); 288 289 #ifdef __powerpc64__ 290 static inline unsigned long 291 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) 292 { 293 return __copy_tofrom_user(to, from, n); 294 } 295 #endif /* __powerpc64__ */ 296 297 static inline unsigned long raw_copy_from_user(void *to, 298 const void __user *from, unsigned long n) 299 { 300 if (__builtin_constant_p(n) && (n <= 8)) { 301 unsigned long ret = 1; 302 303 switch (n) { 304 case 1: 305 __get_user_size(*(u8 *)to, from, 1, ret); 306 break; 307 case 2: 308 __get_user_size(*(u16 *)to, from, 2, ret); 309 break; 310 case 4: 311 __get_user_size(*(u32 *)to, from, 4, ret); 312 break; 313 case 8: 314 __get_user_size(*(u64 *)to, from, 8, ret); 315 break; 316 } 317 if (ret == 0) 318 return 0; 319 } 320 321 return __copy_tofrom_user((__force void __user *)to, from, n); 322 } 323 324 static inline unsigned long raw_copy_to_user(void __user *to, 325 const void *from, unsigned long n) 326 { 327 if (__builtin_constant_p(n) && (n <= 8)) { 328 unsigned long ret = 1; 329 330 switch (n) { 331 case 1: 332 __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret); 333 break; 334 case 2: 335 __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret); 336 break; 337 case 4: 338 __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret); 339 break; 340 case 8: 341 __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret); 342 break; 343 } 344 if (ret == 0) 345 return 0; 346 } 347 348 return __copy_tofrom_user(to, (__force const void __user *)from, n); 349 } 350 351 extern unsigned long __clear_user(void __user *addr, unsigned long size); 352 353 static inline unsigned long clear_user(void __user *addr, unsigned long size) 354 { 355 might_fault(); 356 if (likely(access_ok(VERIFY_WRITE, addr, size))) 357 return __clear_user(addr, size); 358 return size; 359 } 360 361 extern long strncpy_from_user(char *dst, const char __user *src, long count); 362 extern __must_check long strnlen_user(const char __user *str, long n); 363 364 extern long __copy_from_user_flushcache(void *dst, const void __user *src, 365 unsigned size); 366 extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset, 367 size_t len); 368 369 #endif /* _ARCH_POWERPC_UACCESS_H */ 370