xref: /openbmc/qemu/bsd-user/freebsd/os-syscall.c (revision 197a1372)
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     CPUState *cpu = env_cpu(cpu_env);
532     abi_long ret;
533 
534     trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8);
535     if (do_strace) {
536         print_freebsd_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);
537     }
538 
539     ret = freebsd_syscall(cpu_env, num, arg1, arg2, arg3, arg4, arg5, arg6,
540                           arg7, arg8);
541     if (do_strace) {
542         print_freebsd_syscall_ret(num, ret);
543     }
544     trace_guest_user_syscall_ret(cpu, num, ret);
545 
546     return ret;
547 }
548 
549 void syscall_init(void)
550 {
551 }
552