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