kernel/compat.c

   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/futex.h>        /* for FUTEX_WAIT */
  21 #include <linux/unistd.h>
  22
  23 #include <asm/uaccess.h>
  24
  25 int get_compat_timespec(struct timespec *ts, struct compat_timespec *cts)
  26 {
  27         return (verify_area(VERIFY_READ, cts, sizeof(*cts)) ||
  28                         __get_user(ts->tv_sec, &cts->tv_sec) ||
  29                         __get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
  30 }
  31
  32 int put_compat_timespec(struct timespec *ts, struct compat_timespec *cts)
  33 {
  34         return (verify_area(VERIFY_WRITE, cts, sizeof(*cts)) ||
  35                         __put_user(ts->tv_sec, &cts->tv_sec) ||
  36                         __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
  37 }
  38
  39 static long compat_nanosleep_restart(struct restart_block *restart)
  40 {
  41         unsigned long expire = restart->arg0, now = jiffies;
  42         struct compat_timespec *rmtp;
  43
  44         /* Did it expire while we handled signals? */
  45         if (!time_after(expire, now))
  46                 return 0;
  47
  48         current->state = TASK_INTERRUPTIBLE;
  49         expire = schedule_timeout(expire - now);
  50         if (expire == 0)
  51                 return 0;
  52
  53         rmtp = (struct compat_timespec *)restart->arg1;
  54         if (rmtp) {
  55                 struct compat_timespec ct;
  56                 struct timespec t;
  57
  58                 jiffies_to_timespec(expire, &t);
  59                 ct.tv_sec = t.tv_sec;
  60                 ct.tv_nsec = t.tv_nsec;
  61                 if (copy_to_user(rmtp, &ct, sizeof(ct)))
  62                         return -EFAULT;
  63         }
  64         /* The 'restart' block is already filled in */
  65         return -ERESTART_RESTARTBLOCK;
  66 }
  67
  68 asmlinkage long compat_sys_nanosleep(struct compat_timespec *rqtp,
  69                 struct compat_timespec *rmtp)
  70 {
  71         struct timespec t;
  72         struct restart_block *restart;
  73         unsigned long expire;
  74
  75         if (get_compat_timespec(&t, rqtp))
  76                 return -EFAULT;
  77
  78         if ((t.tv_nsec >= 1000000000L) || (t.tv_nsec < 0) || (t.tv_sec < 0))
  79                 return -EINVAL;
  80
  81         expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec);
  82         current->state = TASK_INTERRUPTIBLE;
  83         expire = schedule_timeout(expire);
  84         if (expire == 0)
  85                 return 0;
  86
  87         if (rmtp) {
  88                 jiffies_to_timespec(expire, &t);
  89                 if (put_compat_timespec(&t, rmtp))
  90                         return -EFAULT;
  91         }
  92         restart = &current_thread_info()->restart_block;
  93         restart->fn = compat_nanosleep_restart;
  94         restart->arg0 = jiffies + expire;
  95         restart->arg1 = (unsigned long) rmtp;
  96         return -ERESTART_RESTARTBLOCK;
  97 }
  98
  99 static inline long get_compat_itimerval(struct itimerval *o,
 100                 struct compat_itimerval *i)
 101 {
 102         return (!access_ok(VERIFY_READ, i, sizeof(*i)) ||
 103                 (__get_user(o->it_interval.tv_sec, &i->it_interval.tv_sec) |
 104                  __get_user(o->it_interval.tv_usec, &i->it_interval.tv_usec) |
 105                  __get_user(o->it_value.tv_sec, &i->it_value.tv_sec) |
 106                  __get_user(o->it_value.tv_usec, &i->it_value.tv_usec)));
 107 }
 108
 109 static inline long put_compat_itimerval(struct compat_itimerval *o,
 110                 struct itimerval *i)
 111 {
 112         return (!access_ok(VERIFY_WRITE, o, sizeof(*o)) ||
 113                 (__put_user(i->it_interval.tv_sec, &o->it_interval.tv_sec) |
 114                  __put_user(i->it_interval.tv_usec, &o->it_interval.tv_usec) |
 115                  __put_user(i->it_value.tv_sec, &o->it_value.tv_sec) |
 116                  __put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
 117 }
 118
 119 extern int do_getitimer(int which, struct itimerval *value);
 120
 121 asmlinkage long compat_sys_getitimer(int which, struct compat_itimerval *it)
 122 {
 123         struct itimerval kit;
 124         int error;
 125
 126         error = do_getitimer(which, &kit);
 127         if (!error && put_compat_itimerval(it, &kit))
 128                 error = -EFAULT;
 129         return error;
 130 }
 131
 132 extern int do_setitimer(int which, struct itimerval *, struct itimerval *);
 133
 134 asmlinkage long compat_sys_setitimer(int which, struct compat_itimerval *in,
 135                 struct compat_itimerval *out)
 136 {
 137         struct itimerval kin, kout;
 138         int error;
 139
 140         if (in) {
 141                 if (get_compat_itimerval(&kin, in))
 142                         return -EFAULT;
 143         } else
 144                 memset(&kin, 0, sizeof(kin));
 145
 146         error = do_setitimer(which, &kin, out ? &kout : NULL);
 147         if (error || !out)
 148                 return error;
 149         if (put_compat_itimerval(out, &kout))
 150                 return -EFAULT;
 151         return 0;
 152 }
 153
 154 asmlinkage long compat_sys_times(struct compat_tms *tbuf)
 155 {
 156         /*
 157          *      In the SMP world we might just be unlucky and have one of
 158          *      the times increment as we use it. Since the value is an
 159          *      atomically safe type this is just fine. Conceptually its
 160          *      as if the syscall took an instant longer to occur.
 161          */
 162         if (tbuf) {
 163                 struct compat_tms tmp;
 164                 tmp.tms_utime = compat_jiffies_to_clock_t(current->utime);
 165                 tmp.tms_stime = compat_jiffies_to_clock_t(current->stime);
 166                 tmp.tms_cutime = compat_jiffies_to_clock_t(current->cutime);
 167                 tmp.tms_cstime = compat_jiffies_to_clock_t(current->cstime);
 168                 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
 169                         return -EFAULT;
 170         }
 171         return compat_jiffies_to_clock_t(jiffies);
 172 }
 173
 174 /*
 175  * Assumption: old_sigset_t and compat_old_sigset_t are both
 176  * types that can be passed to put_user()/get_user().
 177  */
 178
 179 extern asmlinkage long sys_sigpending(old_sigset_t *);
 180
 181 asmlinkage long compat_sys_sigpending(compat_old_sigset_t *set)
 182 {
 183         old_sigset_t s;
 184         long ret;
 185         mm_segment_t old_fs = get_fs();
 186
 187         set_fs(KERNEL_DS);
 188         ret = sys_sigpending(&s);
 189         set_fs(old_fs);
 190         if (ret == 0)
 191                 ret = put_user(s, set);
 192         return ret;
 193 }
 194
 195 extern asmlinkage long sys_sigprocmask(int, old_sigset_t *, old_sigset_t *);
 196
 197 asmlinkage long compat_sys_sigprocmask(int how, compat_old_sigset_t *set,
 198                 compat_old_sigset_t *oset)
 199 {
 200         old_sigset_t s;
 201         long ret;
 202         mm_segment_t old_fs;
 203
 204         if (set && get_user(s, set))
 205                 return -EFAULT;
 206         old_fs = get_fs();
 207         set_fs(KERNEL_DS);
 208         ret = sys_sigprocmask(how, set ? &s : NULL, oset ? &s : NULL);
 209         set_fs(old_fs);
 210         if (ret == 0)
 211                 ret = put_user(s, oset);
 212         return ret;
 213 }
 214
 215 #ifdef CONFIG_FUTEX
 216 asmlinkage long compat_sys_futex(u32 *uaddr, int op, int val,
 217                 struct compat_timespec *utime, u32 *uaddr2)
 218 {
 219         struct timespec t;
 220         unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
 221         int val2 = 0;
 222
 223         if ((op == FUTEX_WAIT) && utime) {
 224                 if (get_compat_timespec(&t, utime))
 225                         return -EFAULT;
 226                 timeout = timespec_to_jiffies(&t) + 1;
 227         }
 228         if (op == FUTEX_REQUEUE)
 229                 val2 = (int) (long) utime;
 230
 231         return do_futex((unsigned long)uaddr, op, val, timeout,
 232                         (unsigned long)uaddr2, val2);
 233 }
 234 #endif
 235
 236 asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit *rlim);
 237
 238 asmlinkage long compat_sys_setrlimit(unsigned int resource, struct compat_rlimit *rlim)
 239 {
 240         struct rlimit r;
 241         int ret;
 242         mm_segment_t old_fs = get_fs ();
 243
 244         if (resource >= RLIM_NLIMITS)
 245                 return -EINVAL;
 246
 247         if (!access_ok(VERIFY_READ, rlim, sizeof(*rlim)) ||
 248             __get_user(r.rlim_cur, &rlim->rlim_cur) ||
 249             __get_user(r.rlim_max, &rlim->rlim_max))
 250                 return -EFAULT;
 251
 252         if (r.rlim_cur == COMPAT_RLIM_INFINITY)
 253                 r.rlim_cur = RLIM_INFINITY;
 254         if (r.rlim_max == COMPAT_RLIM_INFINITY)
 255                 r.rlim_max = RLIM_INFINITY;
 256         set_fs(KERNEL_DS);
 257         ret = sys_setrlimit(resource, &r);
 258         set_fs(old_fs);
 259         return ret;
 260 }
 261
 262 #ifdef COMPAT_RLIM_OLD_INFINITY
 263 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit *rlim);
 264
 265 asmlinkage long compat_sys_old_getrlimit(unsigned int resource, struct compat_rlimit *rlim)
 266 {
 267         struct rlimit r;
 268         int ret;
 269         mm_segment_t old_fs = get_fs();
 270
 271         set_fs(KERNEL_DS);
 272         ret = sys_old_getrlimit(resource, &r);
 273         set_fs(old_fs);
 274
 275         if (!ret) {
 276                 if (r.rlim_cur > COMPAT_RLIM_OLD_INFINITY)
 277                         r.rlim_cur = COMPAT_RLIM_INFINITY;
 278                 if (r.rlim_max > COMPAT_RLIM_OLD_INFINITY)
 279                         r.rlim_max = COMPAT_RLIM_INFINITY;
 280
 281                 if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
 282                     __put_user(r.rlim_cur, &rlim->rlim_cur) ||
 283                     __put_user(r.rlim_max, &rlim->rlim_max))
 284                         return -EFAULT;
 285         }
 286         return ret;
 287 }
 288 #endif
 289
 290 asmlinkage long sys_getrlimit (unsigned int resource, struct rlimit *rlim);
 291
 292 asmlinkage long compat_sys_getrlimit (unsigned int resource, struct compat_rlimit *rlim)
 293 {
 294         struct rlimit r;
 295         int ret;
 296         mm_segment_t old_fs = get_fs();
 297
 298         set_fs(KERNEL_DS);
 299         ret = sys_getrlimit(resource, &r);
 300         set_fs(old_fs);
 301         if (!ret) {
 302                 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
 303                         r.rlim_cur = COMPAT_RLIM_INFINITY;
 304                 if (r.rlim_max > COMPAT_RLIM_INFINITY)
 305                         r.rlim_max = COMPAT_RLIM_INFINITY;
 306
 307                 if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
 308                     __put_user(r.rlim_cur, &rlim->rlim_cur) ||
 309                     __put_user(r.rlim_max, &rlim->rlim_max))
 310                         return -EFAULT;
 311         }
 312         return ret;
 313 }
 314
 315 static long put_compat_rusage (struct compat_rusage *ru, struct rusage *r)
 316 {
 317         if (!access_ok(VERIFY_WRITE, ru, sizeof(*ru)) ||
 318             __put_user(r->ru_utime.tv_sec, &ru->ru_utime.tv_sec) ||
 319             __put_user(r->ru_utime.tv_usec, &ru->ru_utime.tv_usec) ||
 320             __put_user(r->ru_stime.tv_sec, &ru->ru_stime.tv_sec) ||
 321             __put_user(r->ru_stime.tv_usec, &ru->ru_stime.tv_usec) ||
 322             __put_user(r->ru_maxrss, &ru->ru_maxrss) ||
 323             __put_user(r->ru_ixrss, &ru->ru_ixrss) ||
 324             __put_user(r->ru_idrss, &ru->ru_idrss) ||
 325             __put_user(r->ru_isrss, &ru->ru_isrss) ||
 326             __put_user(r->ru_minflt, &ru->ru_minflt) ||
 327             __put_user(r->ru_majflt, &ru->ru_majflt) ||
 328             __put_user(r->ru_nswap, &ru->ru_nswap) ||
 329             __put_user(r->ru_inblock, &ru->ru_inblock) ||
 330             __put_user(r->ru_oublock, &ru->ru_oublock) ||
 331             __put_user(r->ru_msgsnd, &ru->ru_msgsnd) ||
 332             __put_user(r->ru_msgrcv, &ru->ru_msgrcv) ||
 333             __put_user(r->ru_nsignals, &ru->ru_nsignals) ||
 334             __put_user(r->ru_nvcsw, &ru->ru_nvcsw) ||
 335             __put_user(r->ru_nivcsw, &ru->ru_nivcsw))
 336                 return -EFAULT;
 337         return 0;
 338 }
 339
 340 asmlinkage long sys_getrusage(int who, struct rusage *ru);
 341
 342 asmlinkage long compat_sys_getrusage(int who, struct compat_rusage *ru)
 343 {
 344         struct rusage r;
 345         int ret;
 346         mm_segment_t old_fs = get_fs();
 347
 348         set_fs(KERNEL_DS);
 349         ret = sys_getrusage(who, &r);
 350         set_fs(old_fs);
 351
 352         return ret || put_compat_rusage(ru, &r);
 353 }
 354
 355 asmlinkage long
 356 compat_sys_wait4(compat_pid_t pid, compat_uint_t * stat_addr, int options,
 357         struct compat_rusage *ru)
 358 {
 359         if (!ru) {
 360                 return sys_wait4(pid, stat_addr, options, NULL);
 361         } else {
 362                 struct rusage r;
 363                 int ret;
 364                 unsigned int status;
 365                 mm_segment_t old_fs = get_fs();
 366
 367                 set_fs (KERNEL_DS);
 368                 ret = sys_wait4(pid, stat_addr ? &status : NULL, options, &r);
 369                 set_fs (old_fs);
 370
 371                 if (!ret)
 372                 {
 373                         if (put_compat_rusage(ru, &r))
 374                                 return -EFAULT;
 375                         if (stat_addr && put_user(status, stat_addr))
 376                                 return -EFAULT;
 377                 }
 378                 return ret;
 379         }
 380 }
 381
 382 extern asmlinkage long sys_sched_setaffinity(pid_t pid, unsigned int len,
 383                                             unsigned long *user_mask_ptr);
 384
 385 asmlinkage long compat_sys_sched_setaffinity(compat_pid_t pid,
 386                                              unsigned int len,
 387                                              compat_ulong_t *user_mask_ptr)
 388 {
 389         unsigned long kernel_mask;
 390         mm_segment_t old_fs;
 391         int ret;
 392
 393         if (get_user(kernel_mask, user_mask_ptr))
 394                 return -EFAULT;
 395
 396         old_fs = get_fs();
 397         set_fs(KERNEL_DS);
 398         ret = sys_sched_setaffinity(pid,
 399                                     sizeof(kernel_mask),
 400                                     &kernel_mask);
 401         set_fs(old_fs);
 402
 403         return ret;
 404 }
 405
 406 extern asmlinkage long sys_sched_getaffinity(pid_t pid, unsigned int len,
 407                                             unsigned long *user_mask_ptr);
 408
 409 asmlinkage int compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len,
 410                                             compat_ulong_t *user_mask_ptr)
 411 {
 412         unsigned long kernel_mask;
 413         mm_segment_t old_fs;
 414         int ret;
 415
 416         old_fs = get_fs();
 417         set_fs(KERNEL_DS);
 418         ret = sys_sched_getaffinity(pid,
 419                                     sizeof(kernel_mask),
 420                                     &kernel_mask);
 421         set_fs(old_fs);
 422
 423         if (ret > 0) {
 424                 if (put_user(kernel_mask, user_mask_ptr))
 425                         ret = -EFAULT;
 426                 ret = sizeof(compat_ulong_t);
 427         }
 428
 429         return ret;
 430 }
 431