1 #ifndef __ALPHA_UACCESS_H 2 #define __ALPHA_UACCESS_H 3 4 /* 5 * The fs value determines whether argument validity checking should be 6 * performed or not. If get_fs() == USER_DS, checking is performed, with 7 * get_fs() == KERNEL_DS, checking is bypassed. 8 * 9 * Or at least it did once upon a time. Nowadays it is a mask that 10 * defines which bits of the address space are off limits. This is a 11 * wee bit faster than the above. 12 * 13 * For historical reasons, these macros are grossly misnamed. 14 */ 15 16 #define KERNEL_DS ((mm_segment_t) { 0UL }) 17 #define USER_DS ((mm_segment_t) { -0x40000000000UL }) 18 19 #define get_fs() (current_thread_info()->addr_limit) 20 #define get_ds() (KERNEL_DS) 21 #define set_fs(x) (current_thread_info()->addr_limit = (x)) 22 23 #define segment_eq(a, b) ((a).seg == (b).seg) 24 25 /* 26 * Is a address valid? This does a straightforward calculation rather 27 * than tests. 28 * 29 * Address valid if: 30 * - "addr" doesn't have any high-bits set 31 * - AND "size" doesn't have any high-bits set 32 * - AND "addr+size" doesn't have any high-bits set 33 * - OR we are in kernel mode. 34 */ 35 #define __access_ok(addr, size) \ 36 ((get_fs().seg & (addr | size | (addr+size))) == 0) 37 38 #define access_ok(type, addr, size) \ 39 ({ \ 40 __chk_user_ptr(addr); \ 41 __access_ok(((unsigned long)(addr)), (size)); \ 42 }) 43 44 /* 45 * These are the main single-value transfer routines. They automatically 46 * use the right size if we just have the right pointer type. 47 * 48 * As the alpha uses the same address space for kernel and user 49 * data, we can just do these as direct assignments. (Of course, the 50 * exception handling means that it's no longer "just"...) 51 * 52 * Careful to not 53 * (a) re-use the arguments for side effects (sizeof/typeof is ok) 54 * (b) require any knowledge of processes at this stage 55 */ 56 #define put_user(x, ptr) \ 57 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 58 #define get_user(x, ptr) \ 59 __get_user_check((x), (ptr), sizeof(*(ptr))) 60 61 /* 62 * The "__xxx" versions do not do address space checking, useful when 63 * doing multiple accesses to the same area (the programmer has to do the 64 * checks by hand with "access_ok()") 65 */ 66 #define __put_user(x, ptr) \ 67 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 68 #define __get_user(x, ptr) \ 69 __get_user_nocheck((x), (ptr), sizeof(*(ptr))) 70 71 /* 72 * The "lda %1, 2b-1b(%0)" bits are magic to get the assembler to 73 * encode the bits we need for resolving the exception. See the 74 * more extensive comments with fixup_inline_exception below for 75 * more information. 76 */ 77 #define EXC(label,cont,res,err) \ 78 ".section __ex_table,\"a\"\n" \ 79 " .long "#label"-.\n" \ 80 " lda "#res","#cont"-"#label"("#err")\n" \ 81 ".previous\n" 82 83 extern void __get_user_unknown(void); 84 85 #define __get_user_nocheck(x, ptr, size) \ 86 ({ \ 87 long __gu_err = 0; \ 88 unsigned long __gu_val; \ 89 __chk_user_ptr(ptr); \ 90 switch (size) { \ 91 case 1: __get_user_8(ptr); break; \ 92 case 2: __get_user_16(ptr); break; \ 93 case 4: __get_user_32(ptr); break; \ 94 case 8: __get_user_64(ptr); break; \ 95 default: __get_user_unknown(); break; \ 96 } \ 97 (x) = (__force __typeof__(*(ptr))) __gu_val; \ 98 __gu_err; \ 99 }) 100 101 #define __get_user_check(x, ptr, size) \ 102 ({ \ 103 long __gu_err = -EFAULT; \ 104 unsigned long __gu_val = 0; \ 105 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 106 if (__access_ok((unsigned long)__gu_addr, size)) { \ 107 __gu_err = 0; \ 108 switch (size) { \ 109 case 1: __get_user_8(__gu_addr); break; \ 110 case 2: __get_user_16(__gu_addr); break; \ 111 case 4: __get_user_32(__gu_addr); break; \ 112 case 8: __get_user_64(__gu_addr); break; \ 113 default: __get_user_unknown(); break; \ 114 } \ 115 } \ 116 (x) = (__force __typeof__(*(ptr))) __gu_val; \ 117 __gu_err; \ 118 }) 119 120 struct __large_struct { unsigned long buf[100]; }; 121 #define __m(x) (*(struct __large_struct __user *)(x)) 122 123 #define __get_user_64(addr) \ 124 __asm__("1: ldq %0,%2\n" \ 125 "2:\n" \ 126 EXC(1b,2b,%0,%1) \ 127 : "=r"(__gu_val), "=r"(__gu_err) \ 128 : "m"(__m(addr)), "1"(__gu_err)) 129 130 #define __get_user_32(addr) \ 131 __asm__("1: ldl %0,%2\n" \ 132 "2:\n" \ 133 EXC(1b,2b,%0,%1) \ 134 : "=r"(__gu_val), "=r"(__gu_err) \ 135 : "m"(__m(addr)), "1"(__gu_err)) 136 137 #ifdef __alpha_bwx__ 138 /* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */ 139 140 #define __get_user_16(addr) \ 141 __asm__("1: ldwu %0,%2\n" \ 142 "2:\n" \ 143 EXC(1b,2b,%0,%1) \ 144 : "=r"(__gu_val), "=r"(__gu_err) \ 145 : "m"(__m(addr)), "1"(__gu_err)) 146 147 #define __get_user_8(addr) \ 148 __asm__("1: ldbu %0,%2\n" \ 149 "2:\n" \ 150 EXC(1b,2b,%0,%1) \ 151 : "=r"(__gu_val), "=r"(__gu_err) \ 152 : "m"(__m(addr)), "1"(__gu_err)) 153 #else 154 /* Unfortunately, we can't get an unaligned access trap for the sub-word 155 load, so we have to do a general unaligned operation. */ 156 157 #define __get_user_16(addr) \ 158 { \ 159 long __gu_tmp; \ 160 __asm__("1: ldq_u %0,0(%3)\n" \ 161 "2: ldq_u %1,1(%3)\n" \ 162 " extwl %0,%3,%0\n" \ 163 " extwh %1,%3,%1\n" \ 164 " or %0,%1,%0\n" \ 165 "3:\n" \ 166 EXC(1b,3b,%0,%2) \ 167 EXC(2b,3b,%0,%2) \ 168 : "=&r"(__gu_val), "=&r"(__gu_tmp), "=r"(__gu_err) \ 169 : "r"(addr), "2"(__gu_err)); \ 170 } 171 172 #define __get_user_8(addr) \ 173 __asm__("1: ldq_u %0,0(%2)\n" \ 174 " extbl %0,%2,%0\n" \ 175 "2:\n" \ 176 EXC(1b,2b,%0,%1) \ 177 : "=&r"(__gu_val), "=r"(__gu_err) \ 178 : "r"(addr), "1"(__gu_err)) 179 #endif 180 181 extern void __put_user_unknown(void); 182 183 #define __put_user_nocheck(x, ptr, size) \ 184 ({ \ 185 long __pu_err = 0; \ 186 __chk_user_ptr(ptr); \ 187 switch (size) { \ 188 case 1: __put_user_8(x, ptr); break; \ 189 case 2: __put_user_16(x, ptr); break; \ 190 case 4: __put_user_32(x, ptr); break; \ 191 case 8: __put_user_64(x, ptr); break; \ 192 default: __put_user_unknown(); break; \ 193 } \ 194 __pu_err; \ 195 }) 196 197 #define __put_user_check(x, ptr, size) \ 198 ({ \ 199 long __pu_err = -EFAULT; \ 200 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 201 if (__access_ok((unsigned long)__pu_addr, size)) { \ 202 __pu_err = 0; \ 203 switch (size) { \ 204 case 1: __put_user_8(x, __pu_addr); break; \ 205 case 2: __put_user_16(x, __pu_addr); break; \ 206 case 4: __put_user_32(x, __pu_addr); break; \ 207 case 8: __put_user_64(x, __pu_addr); break; \ 208 default: __put_user_unknown(); break; \ 209 } \ 210 } \ 211 __pu_err; \ 212 }) 213 214 /* 215 * The "__put_user_xx()" macros tell gcc they read from memory 216 * instead of writing: this is because they do not write to 217 * any memory gcc knows about, so there are no aliasing issues 218 */ 219 #define __put_user_64(x, addr) \ 220 __asm__ __volatile__("1: stq %r2,%1\n" \ 221 "2:\n" \ 222 EXC(1b,2b,$31,%0) \ 223 : "=r"(__pu_err) \ 224 : "m" (__m(addr)), "rJ" (x), "0"(__pu_err)) 225 226 #define __put_user_32(x, addr) \ 227 __asm__ __volatile__("1: stl %r2,%1\n" \ 228 "2:\n" \ 229 EXC(1b,2b,$31,%0) \ 230 : "=r"(__pu_err) \ 231 : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) 232 233 #ifdef __alpha_bwx__ 234 /* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */ 235 236 #define __put_user_16(x, addr) \ 237 __asm__ __volatile__("1: stw %r2,%1\n" \ 238 "2:\n" \ 239 EXC(1b,2b,$31,%0) \ 240 : "=r"(__pu_err) \ 241 : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) 242 243 #define __put_user_8(x, addr) \ 244 __asm__ __volatile__("1: stb %r2,%1\n" \ 245 "2:\n" \ 246 EXC(1b,2b,$31,%0) \ 247 : "=r"(__pu_err) \ 248 : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) 249 #else 250 /* Unfortunately, we can't get an unaligned access trap for the sub-word 251 write, so we have to do a general unaligned operation. */ 252 253 #define __put_user_16(x, addr) \ 254 { \ 255 long __pu_tmp1, __pu_tmp2, __pu_tmp3, __pu_tmp4; \ 256 __asm__ __volatile__( \ 257 "1: ldq_u %2,1(%5)\n" \ 258 "2: ldq_u %1,0(%5)\n" \ 259 " inswh %6,%5,%4\n" \ 260 " inswl %6,%5,%3\n" \ 261 " mskwh %2,%5,%2\n" \ 262 " mskwl %1,%5,%1\n" \ 263 " or %2,%4,%2\n" \ 264 " or %1,%3,%1\n" \ 265 "3: stq_u %2,1(%5)\n" \ 266 "4: stq_u %1,0(%5)\n" \ 267 "5:\n" \ 268 EXC(1b,5b,$31,%0) \ 269 EXC(2b,5b,$31,%0) \ 270 EXC(3b,5b,$31,%0) \ 271 EXC(4b,5b,$31,%0) \ 272 : "=r"(__pu_err), "=&r"(__pu_tmp1), \ 273 "=&r"(__pu_tmp2), "=&r"(__pu_tmp3), \ 274 "=&r"(__pu_tmp4) \ 275 : "r"(addr), "r"((unsigned long)(x)), "0"(__pu_err)); \ 276 } 277 278 #define __put_user_8(x, addr) \ 279 { \ 280 long __pu_tmp1, __pu_tmp2; \ 281 __asm__ __volatile__( \ 282 "1: ldq_u %1,0(%4)\n" \ 283 " insbl %3,%4,%2\n" \ 284 " mskbl %1,%4,%1\n" \ 285 " or %1,%2,%1\n" \ 286 "2: stq_u %1,0(%4)\n" \ 287 "3:\n" \ 288 EXC(1b,3b,$31,%0) \ 289 EXC(2b,3b,$31,%0) \ 290 : "=r"(__pu_err), \ 291 "=&r"(__pu_tmp1), "=&r"(__pu_tmp2) \ 292 : "r"((unsigned long)(x)), "r"(addr), "0"(__pu_err)); \ 293 } 294 #endif 295 296 297 /* 298 * Complex access routines 299 */ 300 301 extern long __copy_user(void *to, const void *from, long len); 302 303 static inline unsigned long 304 raw_copy_from_user(void *to, const void __user *from, unsigned long len) 305 { 306 return __copy_user(to, (__force const void *)from, len); 307 } 308 309 static inline unsigned long 310 raw_copy_to_user(void __user *to, const void *from, unsigned long len) 311 { 312 return __copy_user((__force void *)to, from, len); 313 } 314 315 extern long __clear_user(void __user *to, long len); 316 317 extern inline long 318 clear_user(void __user *to, long len) 319 { 320 if (__access_ok((unsigned long)to, len)) 321 len = __clear_user(to, len); 322 return len; 323 } 324 325 #define user_addr_max() \ 326 (uaccess_kernel() ? ~0UL : TASK_SIZE) 327 328 extern long strncpy_from_user(char *dest, const char __user *src, long count); 329 extern __must_check long strnlen_user(const char __user *str, long n); 330 331 #include <asm/extable.h> 332 333 #endif /* __ALPHA_UACCESS_H */ 334