1 /* 2 * linux/kernel/compat.c 3 * 4 * Kernel compatibililty routines for e.g. 32 bit syscall support 5 * on 64 bit kernels. 6 * 7 * Copyright (C) 2002-2003 Stephen Rothwell, IBM Corporation 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #include <linux/linkage.h> 15 #include <linux/compat.h> 16 #include <linux/errno.h> 17 #include <linux/time.h> 18 #include <linux/signal.h> 19 #include <linux/sched.h> /* for MAX_SCHEDULE_TIMEOUT */ 20 #include <linux/syscalls.h> 21 #include <linux/unistd.h> 22 #include <linux/security.h> 23 #include <linux/timex.h> 24 #include <linux/export.h> 25 #include <linux/migrate.h> 26 #include <linux/posix-timers.h> 27 #include <linux/times.h> 28 #include <linux/ptrace.h> 29 #include <linux/gfp.h> 30 31 #include <linux/uaccess.h> 32 33 int compat_get_timex(struct timex *txc, const struct compat_timex __user *utp) 34 { 35 struct compat_timex tx32; 36 37 memset(txc, 0, sizeof(struct timex)); 38 if (copy_from_user(&tx32, utp, sizeof(struct compat_timex))) 39 return -EFAULT; 40 41 txc->modes = tx32.modes; 42 txc->offset = tx32.offset; 43 txc->freq = tx32.freq; 44 txc->maxerror = tx32.maxerror; 45 txc->esterror = tx32.esterror; 46 txc->status = tx32.status; 47 txc->constant = tx32.constant; 48 txc->precision = tx32.precision; 49 txc->tolerance = tx32.tolerance; 50 txc->time.tv_sec = tx32.time.tv_sec; 51 txc->time.tv_usec = tx32.time.tv_usec; 52 txc->tick = tx32.tick; 53 txc->ppsfreq = tx32.ppsfreq; 54 txc->jitter = tx32.jitter; 55 txc->shift = tx32.shift; 56 txc->stabil = tx32.stabil; 57 txc->jitcnt = tx32.jitcnt; 58 txc->calcnt = tx32.calcnt; 59 txc->errcnt = tx32.errcnt; 60 txc->stbcnt = tx32.stbcnt; 61 62 return 0; 63 } 64 65 int compat_put_timex(struct compat_timex __user *utp, const struct timex *txc) 66 { 67 struct compat_timex tx32; 68 69 memset(&tx32, 0, sizeof(struct compat_timex)); 70 tx32.modes = txc->modes; 71 tx32.offset = txc->offset; 72 tx32.freq = txc->freq; 73 tx32.maxerror = txc->maxerror; 74 tx32.esterror = txc->esterror; 75 tx32.status = txc->status; 76 tx32.constant = txc->constant; 77 tx32.precision = txc->precision; 78 tx32.tolerance = txc->tolerance; 79 tx32.time.tv_sec = txc->time.tv_sec; 80 tx32.time.tv_usec = txc->time.tv_usec; 81 tx32.tick = txc->tick; 82 tx32.ppsfreq = txc->ppsfreq; 83 tx32.jitter = txc->jitter; 84 tx32.shift = txc->shift; 85 tx32.stabil = txc->stabil; 86 tx32.jitcnt = txc->jitcnt; 87 tx32.calcnt = txc->calcnt; 88 tx32.errcnt = txc->errcnt; 89 tx32.stbcnt = txc->stbcnt; 90 tx32.tai = txc->tai; 91 if (copy_to_user(utp, &tx32, sizeof(struct compat_timex))) 92 return -EFAULT; 93 return 0; 94 } 95 96 static int __compat_get_timeval(struct timeval *tv, const struct old_timeval32 __user *ctv) 97 { 98 return (!access_ok(ctv, sizeof(*ctv)) || 99 __get_user(tv->tv_sec, &ctv->tv_sec) || 100 __get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0; 101 } 102 103 static int __compat_put_timeval(const struct timeval *tv, struct old_timeval32 __user *ctv) 104 { 105 return (!access_ok(ctv, sizeof(*ctv)) || 106 __put_user(tv->tv_sec, &ctv->tv_sec) || 107 __put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0; 108 } 109 110 static int __compat_get_timespec(struct timespec *ts, const struct old_timespec32 __user *cts) 111 { 112 return (!access_ok(cts, sizeof(*cts)) || 113 __get_user(ts->tv_sec, &cts->tv_sec) || 114 __get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0; 115 } 116 117 static int __compat_put_timespec(const struct timespec *ts, struct old_timespec32 __user *cts) 118 { 119 return (!access_ok(cts, sizeof(*cts)) || 120 __put_user(ts->tv_sec, &cts->tv_sec) || 121 __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0; 122 } 123 124 int compat_get_timeval(struct timeval *tv, const void __user *utv) 125 { 126 if (COMPAT_USE_64BIT_TIME) 127 return copy_from_user(tv, utv, sizeof(*tv)) ? -EFAULT : 0; 128 else 129 return __compat_get_timeval(tv, utv); 130 } 131 EXPORT_SYMBOL_GPL(compat_get_timeval); 132 133 int compat_put_timeval(const struct timeval *tv, void __user *utv) 134 { 135 if (COMPAT_USE_64BIT_TIME) 136 return copy_to_user(utv, tv, sizeof(*tv)) ? -EFAULT : 0; 137 else 138 return __compat_put_timeval(tv, utv); 139 } 140 EXPORT_SYMBOL_GPL(compat_put_timeval); 141 142 int compat_get_timespec(struct timespec *ts, const void __user *uts) 143 { 144 if (COMPAT_USE_64BIT_TIME) 145 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0; 146 else 147 return __compat_get_timespec(ts, uts); 148 } 149 EXPORT_SYMBOL_GPL(compat_get_timespec); 150 151 int compat_put_timespec(const struct timespec *ts, void __user *uts) 152 { 153 if (COMPAT_USE_64BIT_TIME) 154 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0; 155 else 156 return __compat_put_timespec(ts, uts); 157 } 158 EXPORT_SYMBOL_GPL(compat_put_timespec); 159 160 int get_compat_itimerval(struct itimerval *o, const struct compat_itimerval __user *i) 161 { 162 struct compat_itimerval v32; 163 164 if (copy_from_user(&v32, i, sizeof(struct compat_itimerval))) 165 return -EFAULT; 166 o->it_interval.tv_sec = v32.it_interval.tv_sec; 167 o->it_interval.tv_usec = v32.it_interval.tv_usec; 168 o->it_value.tv_sec = v32.it_value.tv_sec; 169 o->it_value.tv_usec = v32.it_value.tv_usec; 170 return 0; 171 } 172 173 int put_compat_itimerval(struct compat_itimerval __user *o, const struct itimerval *i) 174 { 175 struct compat_itimerval v32; 176 177 v32.it_interval.tv_sec = i->it_interval.tv_sec; 178 v32.it_interval.tv_usec = i->it_interval.tv_usec; 179 v32.it_value.tv_sec = i->it_value.tv_sec; 180 v32.it_value.tv_usec = i->it_value.tv_usec; 181 return copy_to_user(o, &v32, sizeof(struct compat_itimerval)) ? -EFAULT : 0; 182 } 183 184 #ifdef __ARCH_WANT_SYS_SIGPROCMASK 185 186 /* 187 * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the 188 * blocked set of signals to the supplied signal set 189 */ 190 static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set) 191 { 192 memcpy(blocked->sig, &set, sizeof(set)); 193 } 194 195 COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how, 196 compat_old_sigset_t __user *, nset, 197 compat_old_sigset_t __user *, oset) 198 { 199 old_sigset_t old_set, new_set; 200 sigset_t new_blocked; 201 202 old_set = current->blocked.sig[0]; 203 204 if (nset) { 205 if (get_user(new_set, nset)) 206 return -EFAULT; 207 new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP)); 208 209 new_blocked = current->blocked; 210 211 switch (how) { 212 case SIG_BLOCK: 213 sigaddsetmask(&new_blocked, new_set); 214 break; 215 case SIG_UNBLOCK: 216 sigdelsetmask(&new_blocked, new_set); 217 break; 218 case SIG_SETMASK: 219 compat_sig_setmask(&new_blocked, new_set); 220 break; 221 default: 222 return -EINVAL; 223 } 224 225 set_current_blocked(&new_blocked); 226 } 227 228 if (oset) { 229 if (put_user(old_set, oset)) 230 return -EFAULT; 231 } 232 233 return 0; 234 } 235 236 #endif 237 238 int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru) 239 { 240 struct compat_rusage r32; 241 memset(&r32, 0, sizeof(r32)); 242 r32.ru_utime.tv_sec = r->ru_utime.tv_sec; 243 r32.ru_utime.tv_usec = r->ru_utime.tv_usec; 244 r32.ru_stime.tv_sec = r->ru_stime.tv_sec; 245 r32.ru_stime.tv_usec = r->ru_stime.tv_usec; 246 r32.ru_maxrss = r->ru_maxrss; 247 r32.ru_ixrss = r->ru_ixrss; 248 r32.ru_idrss = r->ru_idrss; 249 r32.ru_isrss = r->ru_isrss; 250 r32.ru_minflt = r->ru_minflt; 251 r32.ru_majflt = r->ru_majflt; 252 r32.ru_nswap = r->ru_nswap; 253 r32.ru_inblock = r->ru_inblock; 254 r32.ru_oublock = r->ru_oublock; 255 r32.ru_msgsnd = r->ru_msgsnd; 256 r32.ru_msgrcv = r->ru_msgrcv; 257 r32.ru_nsignals = r->ru_nsignals; 258 r32.ru_nvcsw = r->ru_nvcsw; 259 r32.ru_nivcsw = r->ru_nivcsw; 260 if (copy_to_user(ru, &r32, sizeof(r32))) 261 return -EFAULT; 262 return 0; 263 } 264 265 static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr, 266 unsigned len, struct cpumask *new_mask) 267 { 268 unsigned long *k; 269 270 if (len < cpumask_size()) 271 memset(new_mask, 0, cpumask_size()); 272 else if (len > cpumask_size()) 273 len = cpumask_size(); 274 275 k = cpumask_bits(new_mask); 276 return compat_get_bitmap(k, user_mask_ptr, len * 8); 277 } 278 279 COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid, 280 unsigned int, len, 281 compat_ulong_t __user *, user_mask_ptr) 282 { 283 cpumask_var_t new_mask; 284 int retval; 285 286 if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) 287 return -ENOMEM; 288 289 retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask); 290 if (retval) 291 goto out; 292 293 retval = sched_setaffinity(pid, new_mask); 294 out: 295 free_cpumask_var(new_mask); 296 return retval; 297 } 298 299 COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t, pid, unsigned int, len, 300 compat_ulong_t __user *, user_mask_ptr) 301 { 302 int ret; 303 cpumask_var_t mask; 304 305 if ((len * BITS_PER_BYTE) < nr_cpu_ids) 306 return -EINVAL; 307 if (len & (sizeof(compat_ulong_t)-1)) 308 return -EINVAL; 309 310 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 311 return -ENOMEM; 312 313 ret = sched_getaffinity(pid, mask); 314 if (ret == 0) { 315 unsigned int retlen = min(len, cpumask_size()); 316 317 if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8)) 318 ret = -EFAULT; 319 else 320 ret = retlen; 321 } 322 free_cpumask_var(mask); 323 324 return ret; 325 } 326 327 /* 328 * We currently only need the following fields from the sigevent 329 * structure: sigev_value, sigev_signo, sig_notify and (sometimes 330 * sigev_notify_thread_id). The others are handled in user mode. 331 * We also assume that copying sigev_value.sival_int is sufficient 332 * to keep all the bits of sigev_value.sival_ptr intact. 333 */ 334 int get_compat_sigevent(struct sigevent *event, 335 const struct compat_sigevent __user *u_event) 336 { 337 memset(event, 0, sizeof(*event)); 338 return (!access_ok(u_event, sizeof(*u_event)) || 339 __get_user(event->sigev_value.sival_int, 340 &u_event->sigev_value.sival_int) || 341 __get_user(event->sigev_signo, &u_event->sigev_signo) || 342 __get_user(event->sigev_notify, &u_event->sigev_notify) || 343 __get_user(event->sigev_notify_thread_id, 344 &u_event->sigev_notify_thread_id)) 345 ? -EFAULT : 0; 346 } 347 348 long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask, 349 unsigned long bitmap_size) 350 { 351 unsigned long nr_compat_longs; 352 353 /* align bitmap up to nearest compat_long_t boundary */ 354 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); 355 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); 356 357 if (!user_access_begin(umask, bitmap_size / 8)) 358 return -EFAULT; 359 360 while (nr_compat_longs > 1) { 361 compat_ulong_t l1, l2; 362 unsafe_get_user(l1, umask++, Efault); 363 unsafe_get_user(l2, umask++, Efault); 364 *mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) | l1; 365 nr_compat_longs -= 2; 366 } 367 if (nr_compat_longs) 368 unsafe_get_user(*mask, umask++, Efault); 369 user_access_end(); 370 return 0; 371 372 Efault: 373 user_access_end(); 374 return -EFAULT; 375 } 376 377 long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask, 378 unsigned long bitmap_size) 379 { 380 unsigned long nr_compat_longs; 381 382 /* align bitmap up to nearest compat_long_t boundary */ 383 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); 384 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); 385 386 if (!user_access_begin(umask, bitmap_size / 8)) 387 return -EFAULT; 388 389 while (nr_compat_longs > 1) { 390 unsigned long m = *mask++; 391 unsafe_put_user((compat_ulong_t)m, umask++, Efault); 392 unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault); 393 nr_compat_longs -= 2; 394 } 395 if (nr_compat_longs) 396 unsafe_put_user((compat_ulong_t)*mask, umask++, Efault); 397 user_access_end(); 398 return 0; 399 Efault: 400 user_access_end(); 401 return -EFAULT; 402 } 403 404 int 405 get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat) 406 { 407 #ifdef __BIG_ENDIAN 408 compat_sigset_t v; 409 if (copy_from_user(&v, compat, sizeof(compat_sigset_t))) 410 return -EFAULT; 411 switch (_NSIG_WORDS) { 412 case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 ); 413 case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 ); 414 case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 ); 415 case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 ); 416 } 417 #else 418 if (copy_from_user(set, compat, sizeof(compat_sigset_t))) 419 return -EFAULT; 420 #endif 421 return 0; 422 } 423 EXPORT_SYMBOL_GPL(get_compat_sigset); 424 425 /* 426 * Allocate user-space memory for the duration of a single system call, 427 * in order to marshall parameters inside a compat thunk. 428 */ 429 void __user *compat_alloc_user_space(unsigned long len) 430 { 431 void __user *ptr; 432 433 /* If len would occupy more than half of the entire compat space... */ 434 if (unlikely(len > (((compat_uptr_t)~0) >> 1))) 435 return NULL; 436 437 ptr = arch_compat_alloc_user_space(len); 438 439 if (unlikely(!access_ok(ptr, len))) 440 return NULL; 441 442 return ptr; 443 } 444 EXPORT_SYMBOL_GPL(compat_alloc_user_space); 445