bsd-user/freebsd/os-syscall.c

   1 /*
   2  *  BSD syscalls
   3  *
   4  *  Copyright (c) 2003-2008 Fabrice Bellard
   5  *  Copyright (c) 2013-2014 Stacey D. Son
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 /*
  22  * We need the FreeBSD "legacy" definitions. Rust needs the FreeBSD 11 system
  23  * calls since it doesn't use libc at all, so we have to emulate that despite
  24  * FreeBSD 11 being EOL'd.
  25  */
  26 #define _WANT_FREEBSD11_STAT
  27 #define _WANT_FREEBSD11_STATFS
  28 #define _WANT_FREEBSD11_DIRENT
  29 #define _WANT_KERNEL_ERRNO
  30 #define _WANT_SEMUN
  31 #include "qemu/osdep.h"
  32 #include "qemu/cutils.h"
  33 #include "qemu/path.h"
  34 #include <sys/syscall.h>
  35 #include <sys/cdefs.h>
  36 #include <sys/param.h>
  37 #include <sys/mount.h>
  38 #include <sys/sysctl.h>
  39 #include <utime.h>
  40
  41 #include "include/gdbstub/syscalls.h"
  42
  43 #include "qemu.h"
  44 #include "signal-common.h"
  45 #include "user/syscall-trace.h"
  46
  47 #include "bsd-file.h"
  48 #include "bsd-proc.h"
  49
  50 /* I/O */
  51 safe_syscall3(int, open, const char *, path, int, flags, mode_t, mode);
  52 safe_syscall4(int, openat, int, fd, const char *, path, int, flags, mode_t,
  53     mode);
  54
  55 safe_syscall3(ssize_t, read, int, fd, void *, buf, size_t, nbytes);
  56 safe_syscall4(ssize_t, pread, int, fd, void *, buf, size_t, nbytes, off_t,
  57     offset);
  58 safe_syscall3(ssize_t, readv, int, fd, const struct iovec *, iov, int, iovcnt);
  59 safe_syscall4(ssize_t, preadv, int, fd, const struct iovec *, iov, int, iovcnt,
  60     off_t, offset);
  61
  62 safe_syscall3(ssize_t, write, int, fd, void *, buf, size_t, nbytes);
  63 safe_syscall4(ssize_t, pwrite, int, fd, void *, buf, size_t, nbytes, off_t,
  64     offset);
  65 safe_syscall3(ssize_t, writev, int, fd, const struct iovec *, iov, int, iovcnt);
  66 safe_syscall4(ssize_t, pwritev, int, fd, const struct iovec *, iov, int, iovcnt,
  67     off_t, offset);
  68
  69 void target_set_brk(abi_ulong new_brk)
  70 {
  71 }
  72
  73 /*
  74  * errno conversion.
  75  */
  76 abi_long get_errno(abi_long ret)
  77 {
  78     if (ret == -1) {
  79         return -host_to_target_errno(errno);
  80     } else {
  81         return ret;
  82     }
  83 }
  84
  85 int host_to_target_errno(int err)
  86 {
  87     /*
  88      * All the BSDs have the property that the error numbers are uniform across
  89      * all architectures for a given BSD, though they may vary between different
  90      * BSDs.
  91      */
  92     return err;
  93 }
  94
  95 bool is_error(abi_long ret)
  96 {
  97     return (abi_ulong)ret >= (abi_ulong)(-4096);
  98 }
  99
 100 /*
 101  * Unlocks a iovec. Unlike unlock_iovec, it assumes the tvec array itself is
 102  * already locked from target_addr. It will be unlocked as well as all the iovec
 103  * elements.
 104  */
 105 static void helper_unlock_iovec(struct target_iovec *target_vec,
 106                                 abi_ulong target_addr, struct iovec *vec,
 107                                 int count, int copy)
 108 {
 109     for (int i = 0; i < count; i++) {
 110         abi_ulong base = tswapal(target_vec[i].iov_base);
 111
 112         if (vec[i].iov_base) {
 113             unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0);
 114         }
 115     }
 116     unlock_user(target_vec, target_addr, 0);
 117 }
 118
 119 struct iovec *lock_iovec(int type, abi_ulong target_addr,
 120         int count, int copy)
 121 {
 122     struct target_iovec *target_vec;
 123     struct iovec *vec;
 124     abi_ulong total_len, max_len;
 125     int i;
 126     int err = 0;
 127
 128     if (count == 0) {
 129         errno = 0;
 130         return NULL;
 131     }
 132     if (count < 0 || count > IOV_MAX) {
 133         errno = EINVAL;
 134         return NULL;
 135     }
 136
 137     vec = g_try_new0(struct iovec, count);
 138     if (vec == NULL) {
 139         errno = ENOMEM;
 140         return NULL;
 141     }
 142
 143     target_vec = lock_user(VERIFY_READ, target_addr,
 144                            count * sizeof(struct target_iovec), 1);
 145     if (target_vec == NULL) {
 146         err = EFAULT;
 147         goto fail2;
 148     }
 149
 150     max_len = 0x7fffffff & MIN(TARGET_PAGE_MASK, PAGE_MASK);
 151     total_len = 0;
 152
 153     for (i = 0; i < count; i++) {
 154         abi_ulong base = tswapal(target_vec[i].iov_base);
 155         abi_long len = tswapal(target_vec[i].iov_len);
 156
 157         if (len < 0) {
 158             err = EINVAL;
 159             goto fail;
 160         } else if (len == 0) {
 161             /* Zero length pointer is ignored. */
 162             vec[i].iov_base = 0;
 163         } else {
 164             vec[i].iov_base = lock_user(type, base, len, copy);
 165             /*
 166              * If the first buffer pointer is bad, this is a fault.  But
 167              * subsequent bad buffers will result in a partial write; this is
 168              * realized by filling the vector with null pointers and zero
 169              * lengths.
 170              */
 171             if (!vec[i].iov_base) {
 172                 if (i == 0) {
 173                     err = EFAULT;
 174                     goto fail;
 175                 } else {
 176                     /*
 177                      * Fail all the subsequent addresses, they are already
 178                      * zero'd.
 179                      */
 180                     goto out;
 181                 }
 182             }
 183             if (len > max_len - total_len) {
 184                 len = max_len - total_len;
 185             }
 186         }
 187         vec[i].iov_len = len;
 188         total_len += len;
 189     }
 190 out:
 191     unlock_user(target_vec, target_addr, 0);
 192     return vec;
 193
 194 fail:
 195     helper_unlock_iovec(target_vec, target_addr, vec, i, copy);
 196 fail2:
 197     g_free(vec);
 198     errno = err;
 199     return NULL;
 200 }
 201
 202 void unlock_iovec(struct iovec *vec, abi_ulong target_addr,
 203         int count, int copy)
 204 {
 205     struct target_iovec *target_vec;
 206
 207     target_vec = lock_user(VERIFY_READ, target_addr,
 208                            count * sizeof(struct target_iovec), 1);
 209     if (target_vec) {
 210         helper_unlock_iovec(target_vec, target_addr, vec, count, copy);
 211     }
 212
 213     g_free(vec);
 214 }
 215
 216 /*
 217  * All errnos that freebsd_syscall() returns must be -TARGET_<errcode>.
 218  */
 219 static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1,
 220                                 abi_long arg2, abi_long arg3, abi_long arg4,
 221                                 abi_long arg5, abi_long arg6, abi_long arg7,
 222                                 abi_long arg8)
 223 {
 224     abi_long ret;
 225
 226     switch (num) {
 227         /*
 228          * process system calls
 229          */
 230     case TARGET_FREEBSD_NR_exit: /* exit(2) */
 231         ret = do_bsd_exit(cpu_env, arg1);
 232         break;
 233
 234         /*
 235          * File system calls.
 236          */
 237     case TARGET_FREEBSD_NR_read: /* read(2) */
 238         ret = do_bsd_read(arg1, arg2, arg3);
 239         break;
 240
 241     case TARGET_FREEBSD_NR_pread: /* pread(2) */
 242         ret = do_bsd_pread(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
 243         break;
 244
 245     case TARGET_FREEBSD_NR_readv: /* readv(2) */
 246         ret = do_bsd_readv(arg1, arg2, arg3);
 247         break;
 248
 249     case TARGET_FREEBSD_NR_preadv: /* preadv(2) */
 250         ret = do_bsd_preadv(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
 251
 252     case TARGET_FREEBSD_NR_write: /* write(2) */
 253         ret = do_bsd_write(arg1, arg2, arg3);
 254         break;
 255
 256     case TARGET_FREEBSD_NR_pwrite: /* pwrite(2) */
 257         ret = do_bsd_pwrite(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
 258         break;
 259
 260     case TARGET_FREEBSD_NR_writev: /* writev(2) */
 261         ret = do_bsd_writev(arg1, arg2, arg3);
 262         break;
 263
 264     case TARGET_FREEBSD_NR_pwritev: /* pwritev(2) */
 265         ret = do_bsd_pwritev(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
 266         break;
 267
 268     case TARGET_FREEBSD_NR_open: /* open(2) */
 269         ret = do_bsd_open(arg1, arg2, arg3);
 270         break;
 271
 272     case TARGET_FREEBSD_NR_openat: /* openat(2) */
 273         ret = do_bsd_openat(arg1, arg2, arg3, arg4);
 274         break;
 275
 276     case TARGET_FREEBSD_NR_close: /* close(2) */
 277         ret = do_bsd_close(arg1);
 278         break;
 279
 280     case TARGET_FREEBSD_NR_fdatasync: /* fdatasync(2) */
 281         ret = do_bsd_fdatasync(arg1);
 282         break;
 283
 284     case TARGET_FREEBSD_NR_fsync: /* fsync(2) */
 285         ret = do_bsd_fsync(arg1);
 286         break;
 287
 288     case TARGET_FREEBSD_NR_freebsd12_closefrom: /* closefrom(2) */
 289         ret = do_bsd_closefrom(arg1);
 290         break;
 291
 292     case TARGET_FREEBSD_NR_revoke: /* revoke(2) */
 293         ret = do_bsd_revoke(arg1);
 294         break;
 295
 296     case TARGET_FREEBSD_NR_access: /* access(2) */
 297         ret = do_bsd_access(arg1, arg2);
 298         break;
 299
 300     case TARGET_FREEBSD_NR_eaccess: /* eaccess(2) */
 301         ret = do_bsd_eaccess(arg1, arg2);
 302         break;
 303
 304     case TARGET_FREEBSD_NR_faccessat: /* faccessat(2) */
 305         ret = do_bsd_faccessat(arg1, arg2, arg3, arg4);
 306         break;
 307
 308     case TARGET_FREEBSD_NR_chdir: /* chdir(2) */
 309         ret = do_bsd_chdir(arg1);
 310         break;
 311
 312     case TARGET_FREEBSD_NR_fchdir: /* fchdir(2) */
 313         ret = do_bsd_fchdir(arg1);
 314         break;
 315
 316     case TARGET_FREEBSD_NR_rename: /* rename(2) */
 317         ret = do_bsd_rename(arg1, arg2);
 318         break;
 319
 320     case TARGET_FREEBSD_NR_renameat: /* renameat(2) */
 321         ret = do_bsd_renameat(arg1, arg2, arg3, arg4);
 322         break;
 323
 324     case TARGET_FREEBSD_NR_link: /* link(2) */
 325         ret = do_bsd_link(arg1, arg2);
 326         break;
 327
 328     case TARGET_FREEBSD_NR_linkat: /* linkat(2) */
 329         ret = do_bsd_linkat(arg1, arg2, arg3, arg4, arg5);
 330         break;
 331
 332     case TARGET_FREEBSD_NR_unlink: /* unlink(2) */
 333         ret = do_bsd_unlink(arg1);
 334         break;
 335
 336     case TARGET_FREEBSD_NR_unlinkat: /* unlinkat(2) */
 337         ret = do_bsd_unlinkat(arg1, arg2, arg3);
 338         break;
 339
 340     case TARGET_FREEBSD_NR_mkdir: /* mkdir(2) */
 341         ret = do_bsd_mkdir(arg1, arg2);
 342         break;
 343
 344     case TARGET_FREEBSD_NR_mkdirat: /* mkdirat(2) */
 345         ret = do_bsd_mkdirat(arg1, arg2, arg3);
 346         break;
 347
 348     case TARGET_FREEBSD_NR_rmdir: /* rmdir(2) (XXX no rmdirat()?) */
 349         ret = do_bsd_rmdir(arg1);
 350         break;
 351
 352     case TARGET_FREEBSD_NR___getcwd: /* undocumented __getcwd() */
 353         ret = do_bsd___getcwd(arg1, arg2);
 354         break;
 355
 356     case TARGET_FREEBSD_NR_dup: /* dup(2) */
 357         ret = do_bsd_dup(arg1);
 358         break;
 359
 360     case TARGET_FREEBSD_NR_dup2: /* dup2(2) */
 361         ret = do_bsd_dup2(arg1, arg2);
 362         break;
 363
 364     case TARGET_FREEBSD_NR_truncate: /* truncate(2) */
 365         ret = do_bsd_truncate(cpu_env, arg1, arg2, arg3, arg4);
 366         break;
 367
 368     case TARGET_FREEBSD_NR_ftruncate: /* ftruncate(2) */
 369         ret = do_bsd_ftruncate(cpu_env, arg1, arg2, arg3, arg4);
 370         break;
 371
 372     case TARGET_FREEBSD_NR_acct: /* acct(2) */
 373         ret = do_bsd_acct(arg1);
 374         break;
 375
 376     case TARGET_FREEBSD_NR_sync: /* sync(2) */
 377         ret = do_bsd_sync();
 378         break;
 379
 380     case TARGET_FREEBSD_NR_mount: /* mount(2) */
 381         ret = do_bsd_mount(arg1, arg2, arg3, arg4);
 382         break;
 383
 384     case TARGET_FREEBSD_NR_unmount: /* unmount(2) */
 385         ret = do_bsd_unmount(arg1, arg2);
 386         break;
 387
 388     case TARGET_FREEBSD_NR_nmount: /* nmount(2) */
 389         ret = do_bsd_nmount(arg1, arg2, arg3);
 390         break;
 391
 392     case TARGET_FREEBSD_NR_symlink: /* symlink(2) */
 393         ret = do_bsd_symlink(arg1, arg2);
 394         break;
 395
 396     case TARGET_FREEBSD_NR_symlinkat: /* symlinkat(2) */
 397         ret = do_bsd_symlinkat(arg1, arg2, arg3);
 398         break;
 399
 400     case TARGET_FREEBSD_NR_readlink: /* readlink(2) */
 401         ret = do_bsd_readlink(cpu_env, arg1, arg2, arg3);
 402         break;
 403
 404     case TARGET_FREEBSD_NR_readlinkat: /* readlinkat(2) */
 405         ret = do_bsd_readlinkat(arg1, arg2, arg3, arg4);
 406         break;
 407
 408     case TARGET_FREEBSD_NR_chmod: /* chmod(2) */
 409         ret = do_bsd_chmod(arg1, arg2);
 410         break;
 411
 412     case TARGET_FREEBSD_NR_fchmod: /* fchmod(2) */
 413         ret = do_bsd_fchmod(arg1, arg2);
 414         break;
 415
 416     case TARGET_FREEBSD_NR_lchmod: /* lchmod(2) */
 417         ret = do_bsd_lchmod(arg1, arg2);
 418         break;
 419
 420     case TARGET_FREEBSD_NR_fchmodat: /* fchmodat(2) */
 421         ret = do_bsd_fchmodat(arg1, arg2, arg3, arg4);
 422         break;
 423
 424     case TARGET_FREEBSD_NR_freebsd11_mknod: /* mknod(2) */
 425         ret = do_bsd_freebsd11_mknod(arg1, arg2, arg3);
 426         break;
 427
 428     case TARGET_FREEBSD_NR_freebsd11_mknodat: /* mknodat(2) */
 429         ret = do_bsd_freebsd11_mknodat(arg1, arg2, arg3, arg4);
 430         break;
 431
 432     case TARGET_FREEBSD_NR_mknodat: /* mknodat(2) */
 433         ret = do_bsd_mknodat(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
 434         break;
 435
 436     case TARGET_FREEBSD_NR_chown: /* chown(2) */
 437         ret = do_bsd_chown(arg1, arg2, arg3);
 438         break;
 439
 440     case TARGET_FREEBSD_NR_fchown: /* fchown(2) */
 441         ret = do_bsd_fchown(arg1, arg2, arg3);
 442         break;
 443
 444     case TARGET_FREEBSD_NR_lchown: /* lchown(2) */
 445         ret = do_bsd_lchown(arg1, arg2, arg3);
 446         break;
 447
 448     case TARGET_FREEBSD_NR_fchownat: /* fchownat(2) */
 449         ret = do_bsd_fchownat(arg1, arg2, arg3, arg4, arg5);
 450         break;
 451
 452     case TARGET_FREEBSD_NR_chflags: /* chflags(2) */
 453         ret = do_bsd_chflags(arg1, arg2);
 454         break;
 455
 456     case TARGET_FREEBSD_NR_lchflags: /* lchflags(2) */
 457         ret = do_bsd_lchflags(arg1, arg2);
 458         break;
 459
 460     case TARGET_FREEBSD_NR_fchflags: /* fchflags(2) */
 461         ret = do_bsd_fchflags(arg1, arg2);
 462         break;
 463
 464     case TARGET_FREEBSD_NR_chroot: /* chroot(2) */
 465         ret = do_bsd_chroot(arg1);
 466         break;
 467
 468     case TARGET_FREEBSD_NR_flock: /* flock(2) */
 469         ret = do_bsd_flock(arg1, arg2);
 470         break;
 471
 472     case TARGET_FREEBSD_NR_mkfifo: /* mkfifo(2) */
 473         ret = do_bsd_mkfifo(arg1, arg2);
 474         break;
 475
 476     case TARGET_FREEBSD_NR_mkfifoat: /* mkfifoat(2) */
 477         ret = do_bsd_mkfifoat(arg1, arg2, arg3);
 478         break;
 479
 480     case TARGET_FREEBSD_NR_pathconf: /* pathconf(2) */
 481         ret = do_bsd_pathconf(arg1, arg2);
 482         break;
 483
 484     case TARGET_FREEBSD_NR_lpathconf: /* lpathconf(2) */
 485         ret = do_bsd_lpathconf(arg1, arg2);
 486         break;
 487
 488     case TARGET_FREEBSD_NR_fpathconf: /* fpathconf(2) */
 489         ret = do_bsd_fpathconf(arg1, arg2);
 490         break;
 491
 492     case TARGET_FREEBSD_NR_undelete: /* undelete(2) */
 493         ret = do_bsd_undelete(arg1);
 494         break;
 495
 496         /*
 497          * sys{ctl, arch, call}
 498          */
 499     case TARGET_FREEBSD_NR___sysctl: /* sysctl(3) */
 500         ret = do_freebsd_sysctl(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
 501         break;
 502
 503     case TARGET_FREEBSD_NR___sysctlbyname: /* sysctlbyname(2) */
 504         ret = do_freebsd_sysctlbyname(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
 505         break;
 506
 507     case TARGET_FREEBSD_NR_sysarch: /* sysarch(2) */
 508         ret = do_freebsd_sysarch(cpu_env, arg1, arg2);
 509         break;
 510
 511     default:
 512         qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);
 513         ret = -TARGET_ENOSYS;
 514         break;
 515     }
 516
 517     return ret;
 518 }
 519
 520 /*
 521  * do_freebsd_syscall() should always have a single exit point at the end so
 522  * that actions, such as logging of syscall results, can be performed. This
 523  * as a wrapper around freebsd_syscall() so that actually happens. Since
 524  * that is a singleton, modern compilers will inline it anyway...
 525  */
 526 abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1,
 527                             abi_long arg2, abi_long arg3, abi_long arg4,
 528                             abi_long arg5, abi_long arg6, abi_long arg7,
 529                             abi_long arg8)
 530 {
 531     abi_long ret;
 532
 533     if (do_strace) {
 534         print_freebsd_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);
 535     }
 536
 537     ret = freebsd_syscall(cpu_env, num, arg1, arg2, arg3, arg4, arg5, arg6,
 538                           arg7, arg8);
 539     if (do_strace) {
 540         print_freebsd_syscall_ret(num, ret);
 541     }
 542
 543     return ret;
 544 }
 545
 546 void syscall_init(void)
 547 {
 548 }