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/param.h>
  36 #include <sys/mount.h>
  37 #include <sys/sysctl.h>
  38 #include <utime.h>
  39
  40 #include "qemu.h"
  41 #include "signal-common.h"
  42 #include "user/syscall-trace.h"
  43
  44 #include "bsd-file.h"
  45 #include "bsd-proc.h"
  46
  47 /* I/O */
  48 safe_syscall3(int, open, const char *, path, int, flags, mode_t, mode);
  49 safe_syscall4(int, openat, int, fd, const char *, path, int, flags, mode_t,
  50     mode);
  51
  52 safe_syscall3(ssize_t, read, int, fd, void *, buf, size_t, nbytes);
  53 safe_syscall4(ssize_t, pread, int, fd, void *, buf, size_t, nbytes, off_t,
  54     offset);
  55 safe_syscall3(ssize_t, readv, int, fd, const struct iovec *, iov, int, iovcnt);
  56 safe_syscall4(ssize_t, preadv, int, fd, const struct iovec *, iov, int, iovcnt,
  57     off_t, offset);
  58
  59 safe_syscall3(ssize_t, write, int, fd, void *, buf, size_t, nbytes);
  60 safe_syscall4(ssize_t, pwrite, int, fd, void *, buf, size_t, nbytes, off_t,
  61     offset);
  62 safe_syscall3(ssize_t, writev, int, fd, const struct iovec *, iov, int, iovcnt);
  63 safe_syscall4(ssize_t, pwritev, int, fd, const struct iovec *, iov, int, iovcnt,
  64     off_t, offset);
  65
  66 void target_set_brk(abi_ulong new_brk)
  67 {
  68 }
  69
  70 /*
  71  * errno conversion.
  72  */
  73 abi_long get_errno(abi_long ret)
  74 {
  75     if (ret == -1) {
  76         return -host_to_target_errno(errno);
  77     } else {
  78         return ret;
  79     }
  80 }
  81
  82 int host_to_target_errno(int err)
  83 {
  84     /*
  85      * All the BSDs have the property that the error numbers are uniform across
  86      * all architectures for a given BSD, though they may vary between different
  87      * BSDs.
  88      */
  89     return err;
  90 }
  91
  92 bool is_error(abi_long ret)
  93 {
  94     return (abi_ulong)ret >= (abi_ulong)(-4096);
  95 }
  96
  97 /*
  98  * Unlocks a iovec. Unlike unlock_iovec, it assumes the tvec array itself is
  99  * already locked from target_addr. It will be unlocked as well as all the iovec
 100  * elements.
 101  */
 102 static void helper_unlock_iovec(struct target_iovec *target_vec,
 103                                 abi_ulong target_addr, struct iovec *vec,
 104                                 int count, int copy)
 105 {
 106     for (int i = 0; i < count; i++) {
 107         abi_ulong base = tswapal(target_vec[i].iov_base);
 108
 109         if (vec[i].iov_base) {
 110             unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0);
 111         }
 112     }
 113     unlock_user(target_vec, target_addr, 0);
 114 }
 115
 116 struct iovec *lock_iovec(int type, abi_ulong target_addr,
 117         int count, int copy)
 118 {
 119     struct target_iovec *target_vec;
 120     struct iovec *vec;
 121     abi_ulong total_len, max_len;
 122     int i;
 123     int err = 0;
 124
 125     if (count == 0) {
 126         errno = 0;
 127         return NULL;
 128     }
 129     if (count < 0 || count > IOV_MAX) {
 130         errno = EINVAL;
 131         return NULL;
 132     }
 133
 134     vec = g_try_new0(struct iovec, count);
 135     if (vec == NULL) {
 136         errno = ENOMEM;
 137         return NULL;
 138     }
 139
 140     target_vec = lock_user(VERIFY_READ, target_addr,
 141                            count * sizeof(struct target_iovec), 1);
 142     if (target_vec == NULL) {
 143         err = EFAULT;
 144         goto fail2;
 145     }
 146
 147     max_len = 0x7fffffff & MIN(TARGET_PAGE_MASK, PAGE_MASK);
 148     total_len = 0;
 149
 150     for (i = 0; i < count; i++) {
 151         abi_ulong base = tswapal(target_vec[i].iov_base);
 152         abi_long len = tswapal(target_vec[i].iov_len);
 153
 154         if (len < 0) {
 155             err = EINVAL;
 156             goto fail;
 157         } else if (len == 0) {
 158             /* Zero length pointer is ignored. */
 159             vec[i].iov_base = 0;
 160         } else {
 161             vec[i].iov_base = lock_user(type, base, len, copy);
 162             /*
 163              * If the first buffer pointer is bad, this is a fault.  But
 164              * subsequent bad buffers will result in a partial write; this is
 165              * realized by filling the vector with null pointers and zero
 166              * lengths.
 167              */
 168             if (!vec[i].iov_base) {
 169                 if (i == 0) {
 170                     err = EFAULT;
 171                     goto fail;
 172                 } else {
 173                     /*
 174                      * Fail all the subsequent addresses, they are already
 175                      * zero'd.
 176                      */
 177                     goto out;
 178                 }
 179             }
 180             if (len > max_len - total_len) {
 181                 len = max_len - total_len;
 182             }
 183         }
 184         vec[i].iov_len = len;
 185         total_len += len;
 186     }
 187 out:
 188     unlock_user(target_vec, target_addr, 0);
 189     return vec;
 190
 191 fail:
 192     helper_unlock_iovec(target_vec, target_addr, vec, i, copy);
 193 fail2:
 194     g_free(vec);
 195     errno = err;
 196     return NULL;
 197 }
 198
 199 void unlock_iovec(struct iovec *vec, abi_ulong target_addr,
 200         int count, int copy)
 201 {
 202     struct target_iovec *target_vec;
 203
 204     target_vec = lock_user(VERIFY_READ, target_addr,
 205                            count * sizeof(struct target_iovec), 1);
 206     if (target_vec) {
 207         helper_unlock_iovec(target_vec, target_addr, vec, count, copy);
 208     }
 209
 210     g_free(vec);
 211 }
 212
 213 /*
 214  * All errnos that freebsd_syscall() returns must be -TARGET_<errcode>.
 215  */
 216 static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1,
 217                                 abi_long arg2, abi_long arg3, abi_long arg4,
 218                                 abi_long arg5, abi_long arg6, abi_long arg7,
 219                                 abi_long arg8)
 220 {
 221     abi_long ret;
 222
 223     switch (num) {
 224         /*
 225          * process system calls
 226          */
 227     case TARGET_FREEBSD_NR_exit: /* exit(2) */
 228         ret = do_bsd_exit(cpu_env, arg1);
 229         break;
 230
 231         /*
 232          * File system calls.
 233          */
 234     case TARGET_FREEBSD_NR_read: /* read(2) */
 235         ret = do_bsd_read(arg1, arg2, arg3);
 236         break;
 237
 238     case TARGET_FREEBSD_NR_pread: /* pread(2) */
 239         ret = do_bsd_pread(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
 240         break;
 241
 242     case TARGET_FREEBSD_NR_readv: /* readv(2) */
 243         ret = do_bsd_readv(arg1, arg2, arg3);
 244         break;
 245
 246     case TARGET_FREEBSD_NR_preadv: /* preadv(2) */
 247         ret = do_bsd_preadv(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
 248
 249     case TARGET_FREEBSD_NR_write: /* write(2) */
 250         ret = do_bsd_write(arg1, arg2, arg3);
 251         break;
 252
 253     case TARGET_FREEBSD_NR_pwrite: /* pwrite(2) */
 254         ret = do_bsd_pwrite(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
 255         break;
 256
 257     case TARGET_FREEBSD_NR_writev: /* writev(2) */
 258         ret = do_bsd_writev(arg1, arg2, arg3);
 259         break;
 260
 261     case TARGET_FREEBSD_NR_pwritev: /* pwritev(2) */
 262         ret = do_bsd_pwritev(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
 263         break;
 264
 265     case TARGET_FREEBSD_NR_open: /* open(2) */
 266         ret = do_bsd_open(arg1, arg2, arg3);
 267         break;
 268
 269     case TARGET_FREEBSD_NR_openat: /* openat(2) */
 270         ret = do_bsd_openat(arg1, arg2, arg3, arg4);
 271         break;
 272
 273     case TARGET_FREEBSD_NR_close: /* close(2) */
 274         ret = do_bsd_close(arg1);
 275         break;
 276
 277     case TARGET_FREEBSD_NR_fdatasync: /* fdatasync(2) */
 278         ret = do_bsd_fdatasync(arg1);
 279         break;
 280
 281     case TARGET_FREEBSD_NR_fsync: /* fsync(2) */
 282         ret = do_bsd_fsync(arg1);
 283         break;
 284
 285     case TARGET_FREEBSD_NR_freebsd12_closefrom: /* closefrom(2) */
 286         ret = do_bsd_closefrom(arg1);
 287         break;
 288
 289     case TARGET_FREEBSD_NR_revoke: /* revoke(2) */
 290         ret = do_bsd_revoke(arg1);
 291         break;
 292
 293     case TARGET_FREEBSD_NR_access: /* access(2) */
 294         ret = do_bsd_access(arg1, arg2);
 295         break;
 296
 297     case TARGET_FREEBSD_NR_eaccess: /* eaccess(2) */
 298         ret = do_bsd_eaccess(arg1, arg2);
 299         break;
 300
 301     case TARGET_FREEBSD_NR_faccessat: /* faccessat(2) */
 302         ret = do_bsd_faccessat(arg1, arg2, arg3, arg4);
 303         break;
 304
 305     case TARGET_FREEBSD_NR_chdir: /* chdir(2) */
 306         ret = do_bsd_chdir(arg1);
 307         break;
 308
 309     case TARGET_FREEBSD_NR_fchdir: /* fchdir(2) */
 310         ret = do_bsd_fchdir(arg1);
 311         break;
 312
 313     case TARGET_FREEBSD_NR_rename: /* rename(2) */
 314         ret = do_bsd_rename(arg1, arg2);
 315         break;
 316
 317     case TARGET_FREEBSD_NR_renameat: /* renameat(2) */
 318         ret = do_bsd_renameat(arg1, arg2, arg3, arg4);
 319         break;
 320
 321     case TARGET_FREEBSD_NR_link: /* link(2) */
 322         ret = do_bsd_link(arg1, arg2);
 323         break;
 324
 325     case TARGET_FREEBSD_NR_linkat: /* linkat(2) */
 326         ret = do_bsd_linkat(arg1, arg2, arg3, arg4, arg5);
 327         break;
 328
 329     case TARGET_FREEBSD_NR_unlink: /* unlink(2) */
 330         ret = do_bsd_unlink(arg1);
 331         break;
 332
 333     case TARGET_FREEBSD_NR_unlinkat: /* unlinkat(2) */
 334         ret = do_bsd_unlinkat(arg1, arg2, arg3);
 335         break;
 336
 337     case TARGET_FREEBSD_NR_mkdir: /* mkdir(2) */
 338         ret = do_bsd_mkdir(arg1, arg2);
 339         break;
 340
 341     case TARGET_FREEBSD_NR_mkdirat: /* mkdirat(2) */
 342         ret = do_bsd_mkdirat(arg1, arg2, arg3);
 343         break;
 344
 345     case TARGET_FREEBSD_NR_rmdir: /* rmdir(2) (XXX no rmdirat()?) */
 346         ret = do_bsd_rmdir(arg1);
 347         break;
 348
 349     case TARGET_FREEBSD_NR___getcwd: /* undocumented __getcwd() */
 350         ret = do_bsd___getcwd(arg1, arg2);
 351         break;
 352
 353     case TARGET_FREEBSD_NR_dup: /* dup(2) */
 354         ret = do_bsd_dup(arg1);
 355         break;
 356
 357     case TARGET_FREEBSD_NR_dup2: /* dup2(2) */
 358         ret = do_bsd_dup2(arg1, arg2);
 359         break;
 360
 361     case TARGET_FREEBSD_NR_truncate: /* truncate(2) */
 362         ret = do_bsd_truncate(cpu_env, arg1, arg2, arg3, arg4);
 363         break;
 364
 365     case TARGET_FREEBSD_NR_ftruncate: /* ftruncate(2) */
 366         ret = do_bsd_ftruncate(cpu_env, arg1, arg2, arg3, arg4);
 367         break;
 368
 369     case TARGET_FREEBSD_NR_acct: /* acct(2) */
 370         ret = do_bsd_acct(arg1);
 371         break;
 372
 373     case TARGET_FREEBSD_NR_sync: /* sync(2) */
 374         ret = do_bsd_sync();
 375         break;
 376
 377     case TARGET_FREEBSD_NR_mount: /* mount(2) */
 378         ret = do_bsd_mount(arg1, arg2, arg3, arg4);
 379         break;
 380
 381     case TARGET_FREEBSD_NR_unmount: /* unmount(2) */
 382         ret = do_bsd_unmount(arg1, arg2);
 383         break;
 384
 385     case TARGET_FREEBSD_NR_nmount: /* nmount(2) */
 386         ret = do_bsd_nmount(arg1, arg2, arg3);
 387         break;
 388
 389     default:
 390         qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);
 391         ret = -TARGET_ENOSYS;
 392         break;
 393     }
 394
 395     return ret;
 396 }
 397
 398 /*
 399  * do_freebsd_syscall() should always have a single exit point at the end so
 400  * that actions, such as logging of syscall results, can be performed. This
 401  * as a wrapper around freebsd_syscall() so that actually happens. Since
 402  * that is a singleton, modern compilers will inline it anyway...
 403  */
 404 abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1,
 405                             abi_long arg2, abi_long arg3, abi_long arg4,
 406                             abi_long arg5, abi_long arg6, abi_long arg7,
 407                             abi_long arg8)
 408 {
 409     CPUState *cpu = env_cpu(cpu_env);
 410     int ret;
 411
 412     trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8);
 413     if (do_strace) {
 414         print_freebsd_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);
 415     }
 416
 417     ret = freebsd_syscall(cpu_env, num, arg1, arg2, arg3, arg4, arg5, arg6,
 418                           arg7, arg8);
 419     if (do_strace) {
 420         print_freebsd_syscall_ret(num, ret);
 421     }
 422     trace_guest_user_syscall_ret(cpu, num, ret);
 423
 424     return ret;
 425 }
 426
 427 void syscall_init(void)
 428 {
 429 }