xref: /openbmc/qemu/bsd-user/freebsd/os-syscall.c (revision f2b90109)
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 "qemu.h"
42 #include "signal-common.h"
43 #include "user/syscall-trace.h"
44 
45 #include "bsd-file.h"
46 #include "bsd-proc.h"
47 
48 /* I/O */
49 safe_syscall3(int, open, const char *, path, int, flags, mode_t, mode);
50 safe_syscall4(int, openat, int, fd, const char *, path, int, flags, mode_t,
51     mode);
52 
53 safe_syscall3(ssize_t, read, int, fd, void *, buf, size_t, nbytes);
54 safe_syscall4(ssize_t, pread, int, fd, void *, buf, size_t, nbytes, off_t,
55     offset);
56 safe_syscall3(ssize_t, readv, int, fd, const struct iovec *, iov, int, iovcnt);
57 safe_syscall4(ssize_t, preadv, int, fd, const struct iovec *, iov, int, iovcnt,
58     off_t, offset);
59 
60 safe_syscall3(ssize_t, write, int, fd, void *, buf, size_t, nbytes);
61 safe_syscall4(ssize_t, pwrite, int, fd, void *, buf, size_t, nbytes, off_t,
62     offset);
63 safe_syscall3(ssize_t, writev, int, fd, const struct iovec *, iov, int, iovcnt);
64 safe_syscall4(ssize_t, pwritev, int, fd, const struct iovec *, iov, int, iovcnt,
65     off_t, offset);
66 
67 void target_set_brk(abi_ulong new_brk)
68 {
69 }
70 
71 /*
72  * errno conversion.
73  */
74 abi_long get_errno(abi_long ret)
75 {
76     if (ret == -1) {
77         return -host_to_target_errno(errno);
78     } else {
79         return ret;
80     }
81 }
82 
83 int host_to_target_errno(int err)
84 {
85     /*
86      * All the BSDs have the property that the error numbers are uniform across
87      * all architectures for a given BSD, though they may vary between different
88      * BSDs.
89      */
90     return err;
91 }
92 
93 bool is_error(abi_long ret)
94 {
95     return (abi_ulong)ret >= (abi_ulong)(-4096);
96 }
97 
98 /*
99  * Unlocks a iovec. Unlike unlock_iovec, it assumes the tvec array itself is
100  * already locked from target_addr. It will be unlocked as well as all the iovec
101  * elements.
102  */
103 static void helper_unlock_iovec(struct target_iovec *target_vec,
104                                 abi_ulong target_addr, struct iovec *vec,
105                                 int count, int copy)
106 {
107     for (int i = 0; i < count; i++) {
108         abi_ulong base = tswapal(target_vec[i].iov_base);
109 
110         if (vec[i].iov_base) {
111             unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0);
112         }
113     }
114     unlock_user(target_vec, target_addr, 0);
115 }
116 
117 struct iovec *lock_iovec(int type, abi_ulong target_addr,
118         int count, int copy)
119 {
120     struct target_iovec *target_vec;
121     struct iovec *vec;
122     abi_ulong total_len, max_len;
123     int i;
124     int err = 0;
125 
126     if (count == 0) {
127         errno = 0;
128         return NULL;
129     }
130     if (count < 0 || count > IOV_MAX) {
131         errno = EINVAL;
132         return NULL;
133     }
134 
135     vec = g_try_new0(struct iovec, count);
136     if (vec == NULL) {
137         errno = ENOMEM;
138         return NULL;
139     }
140 
141     target_vec = lock_user(VERIFY_READ, target_addr,
142                            count * sizeof(struct target_iovec), 1);
143     if (target_vec == NULL) {
144         err = EFAULT;
145         goto fail2;
146     }
147 
148     max_len = 0x7fffffff & MIN(TARGET_PAGE_MASK, PAGE_MASK);
149     total_len = 0;
150 
151     for (i = 0; i < count; i++) {
152         abi_ulong base = tswapal(target_vec[i].iov_base);
153         abi_long len = tswapal(target_vec[i].iov_len);
154 
155         if (len < 0) {
156             err = EINVAL;
157             goto fail;
158         } else if (len == 0) {
159             /* Zero length pointer is ignored. */
160             vec[i].iov_base = 0;
161         } else {
162             vec[i].iov_base = lock_user(type, base, len, copy);
163             /*
164              * If the first buffer pointer is bad, this is a fault.  But
165              * subsequent bad buffers will result in a partial write; this is
166              * realized by filling the vector with null pointers and zero
167              * lengths.
168              */
169             if (!vec[i].iov_base) {
170                 if (i == 0) {
171                     err = EFAULT;
172                     goto fail;
173                 } else {
174                     /*
175                      * Fail all the subsequent addresses, they are already
176                      * zero'd.
177                      */
178                     goto out;
179                 }
180             }
181             if (len > max_len - total_len) {
182                 len = max_len - total_len;
183             }
184         }
185         vec[i].iov_len = len;
186         total_len += len;
187     }
188 out:
189     unlock_user(target_vec, target_addr, 0);
190     return vec;
191 
192 fail:
193     helper_unlock_iovec(target_vec, target_addr, vec, i, copy);
194 fail2:
195     g_free(vec);
196     errno = err;
197     return NULL;
198 }
199 
200 void unlock_iovec(struct iovec *vec, abi_ulong target_addr,
201         int count, int copy)
202 {
203     struct target_iovec *target_vec;
204 
205     target_vec = lock_user(VERIFY_READ, target_addr,
206                            count * sizeof(struct target_iovec), 1);
207     if (target_vec) {
208         helper_unlock_iovec(target_vec, target_addr, vec, count, copy);
209     }
210 
211     g_free(vec);
212 }
213 
214 /*
215  * All errnos that freebsd_syscall() returns must be -TARGET_<errcode>.
216  */
217 static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1,
218                                 abi_long arg2, abi_long arg3, abi_long arg4,
219                                 abi_long arg5, abi_long arg6, abi_long arg7,
220                                 abi_long arg8)
221 {
222     abi_long ret;
223 
224     switch (num) {
225         /*
226          * process system calls
227          */
228     case TARGET_FREEBSD_NR_exit: /* exit(2) */
229         ret = do_bsd_exit(cpu_env, arg1);
230         break;
231 
232         /*
233          * File system calls.
234          */
235     case TARGET_FREEBSD_NR_read: /* read(2) */
236         ret = do_bsd_read(arg1, arg2, arg3);
237         break;
238 
239     case TARGET_FREEBSD_NR_pread: /* pread(2) */
240         ret = do_bsd_pread(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
241         break;
242 
243     case TARGET_FREEBSD_NR_readv: /* readv(2) */
244         ret = do_bsd_readv(arg1, arg2, arg3);
245         break;
246 
247     case TARGET_FREEBSD_NR_preadv: /* preadv(2) */
248         ret = do_bsd_preadv(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
249 
250     case TARGET_FREEBSD_NR_write: /* write(2) */
251         ret = do_bsd_write(arg1, arg2, arg3);
252         break;
253 
254     case TARGET_FREEBSD_NR_pwrite: /* pwrite(2) */
255         ret = do_bsd_pwrite(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
256         break;
257 
258     case TARGET_FREEBSD_NR_writev: /* writev(2) */
259         ret = do_bsd_writev(arg1, arg2, arg3);
260         break;
261 
262     case TARGET_FREEBSD_NR_pwritev: /* pwritev(2) */
263         ret = do_bsd_pwritev(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
264         break;
265 
266     case TARGET_FREEBSD_NR_open: /* open(2) */
267         ret = do_bsd_open(arg1, arg2, arg3);
268         break;
269 
270     case TARGET_FREEBSD_NR_openat: /* openat(2) */
271         ret = do_bsd_openat(arg1, arg2, arg3, arg4);
272         break;
273 
274     case TARGET_FREEBSD_NR_close: /* close(2) */
275         ret = do_bsd_close(arg1);
276         break;
277 
278     case TARGET_FREEBSD_NR_fdatasync: /* fdatasync(2) */
279         ret = do_bsd_fdatasync(arg1);
280         break;
281 
282     case TARGET_FREEBSD_NR_fsync: /* fsync(2) */
283         ret = do_bsd_fsync(arg1);
284         break;
285 
286     case TARGET_FREEBSD_NR_freebsd12_closefrom: /* closefrom(2) */
287         ret = do_bsd_closefrom(arg1);
288         break;
289 
290     case TARGET_FREEBSD_NR_revoke: /* revoke(2) */
291         ret = do_bsd_revoke(arg1);
292         break;
293 
294     case TARGET_FREEBSD_NR_access: /* access(2) */
295         ret = do_bsd_access(arg1, arg2);
296         break;
297 
298     case TARGET_FREEBSD_NR_eaccess: /* eaccess(2) */
299         ret = do_bsd_eaccess(arg1, arg2);
300         break;
301 
302     case TARGET_FREEBSD_NR_faccessat: /* faccessat(2) */
303         ret = do_bsd_faccessat(arg1, arg2, arg3, arg4);
304         break;
305 
306     case TARGET_FREEBSD_NR_chdir: /* chdir(2) */
307         ret = do_bsd_chdir(arg1);
308         break;
309 
310     case TARGET_FREEBSD_NR_fchdir: /* fchdir(2) */
311         ret = do_bsd_fchdir(arg1);
312         break;
313 
314     case TARGET_FREEBSD_NR_rename: /* rename(2) */
315         ret = do_bsd_rename(arg1, arg2);
316         break;
317 
318     case TARGET_FREEBSD_NR_renameat: /* renameat(2) */
319         ret = do_bsd_renameat(arg1, arg2, arg3, arg4);
320         break;
321 
322     case TARGET_FREEBSD_NR_link: /* link(2) */
323         ret = do_bsd_link(arg1, arg2);
324         break;
325 
326     case TARGET_FREEBSD_NR_linkat: /* linkat(2) */
327         ret = do_bsd_linkat(arg1, arg2, arg3, arg4, arg5);
328         break;
329 
330     case TARGET_FREEBSD_NR_unlink: /* unlink(2) */
331         ret = do_bsd_unlink(arg1);
332         break;
333 
334     case TARGET_FREEBSD_NR_unlinkat: /* unlinkat(2) */
335         ret = do_bsd_unlinkat(arg1, arg2, arg3);
336         break;
337 
338     case TARGET_FREEBSD_NR_mkdir: /* mkdir(2) */
339         ret = do_bsd_mkdir(arg1, arg2);
340         break;
341 
342     case TARGET_FREEBSD_NR_mkdirat: /* mkdirat(2) */
343         ret = do_bsd_mkdirat(arg1, arg2, arg3);
344         break;
345 
346     case TARGET_FREEBSD_NR_rmdir: /* rmdir(2) (XXX no rmdirat()?) */
347         ret = do_bsd_rmdir(arg1);
348         break;
349 
350     case TARGET_FREEBSD_NR___getcwd: /* undocumented __getcwd() */
351         ret = do_bsd___getcwd(arg1, arg2);
352         break;
353 
354     case TARGET_FREEBSD_NR_dup: /* dup(2) */
355         ret = do_bsd_dup(arg1);
356         break;
357 
358     case TARGET_FREEBSD_NR_dup2: /* dup2(2) */
359         ret = do_bsd_dup2(arg1, arg2);
360         break;
361 
362     case TARGET_FREEBSD_NR_truncate: /* truncate(2) */
363         ret = do_bsd_truncate(cpu_env, arg1, arg2, arg3, arg4);
364         break;
365 
366     case TARGET_FREEBSD_NR_ftruncate: /* ftruncate(2) */
367         ret = do_bsd_ftruncate(cpu_env, arg1, arg2, arg3, arg4);
368         break;
369 
370     case TARGET_FREEBSD_NR_acct: /* acct(2) */
371         ret = do_bsd_acct(arg1);
372         break;
373 
374     case TARGET_FREEBSD_NR_sync: /* sync(2) */
375         ret = do_bsd_sync();
376         break;
377 
378     case TARGET_FREEBSD_NR_mount: /* mount(2) */
379         ret = do_bsd_mount(arg1, arg2, arg3, arg4);
380         break;
381 
382     case TARGET_FREEBSD_NR_unmount: /* unmount(2) */
383         ret = do_bsd_unmount(arg1, arg2);
384         break;
385 
386     case TARGET_FREEBSD_NR_nmount: /* nmount(2) */
387         ret = do_bsd_nmount(arg1, arg2, arg3);
388         break;
389 
390     case TARGET_FREEBSD_NR_symlink: /* symlink(2) */
391         ret = do_bsd_symlink(arg1, arg2);
392         break;
393 
394     case TARGET_FREEBSD_NR_symlinkat: /* symlinkat(2) */
395         ret = do_bsd_symlinkat(arg1, arg2, arg3);
396         break;
397 
398     case TARGET_FREEBSD_NR_readlink: /* readlink(2) */
399         ret = do_bsd_readlink(cpu_env, arg1, arg2, arg3);
400         break;
401 
402     case TARGET_FREEBSD_NR_readlinkat: /* readlinkat(2) */
403         ret = do_bsd_readlinkat(arg1, arg2, arg3, arg4);
404         break;
405 
406     case TARGET_FREEBSD_NR_chmod: /* chmod(2) */
407         ret = do_bsd_chmod(arg1, arg2);
408         break;
409 
410     case TARGET_FREEBSD_NR_fchmod: /* fchmod(2) */
411         ret = do_bsd_fchmod(arg1, arg2);
412         break;
413 
414     case TARGET_FREEBSD_NR_lchmod: /* lchmod(2) */
415         ret = do_bsd_lchmod(arg1, arg2);
416         break;
417 
418     case TARGET_FREEBSD_NR_fchmodat: /* fchmodat(2) */
419         ret = do_bsd_fchmodat(arg1, arg2, arg3, arg4);
420         break;
421 
422     case TARGET_FREEBSD_NR_freebsd11_mknod: /* mknod(2) */
423         ret = do_bsd_freebsd11_mknod(arg1, arg2, arg3);
424         break;
425 
426     case TARGET_FREEBSD_NR_freebsd11_mknodat: /* mknodat(2) */
427         ret = do_bsd_freebsd11_mknodat(arg1, arg2, arg3, arg4);
428         break;
429 
430     case TARGET_FREEBSD_NR_mknodat: /* mknodat(2) */
431         ret = do_bsd_mknodat(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
432         break;
433 
434     case TARGET_FREEBSD_NR_chown: /* chown(2) */
435         ret = do_bsd_chown(arg1, arg2, arg3);
436         break;
437 
438     case TARGET_FREEBSD_NR_fchown: /* fchown(2) */
439         ret = do_bsd_fchown(arg1, arg2, arg3);
440         break;
441 
442     case TARGET_FREEBSD_NR_lchown: /* lchown(2) */
443         ret = do_bsd_lchown(arg1, arg2, arg3);
444         break;
445 
446     case TARGET_FREEBSD_NR_fchownat: /* fchownat(2) */
447         ret = do_bsd_fchownat(arg1, arg2, arg3, arg4, arg5);
448         break;
449 
450     case TARGET_FREEBSD_NR_chflags: /* chflags(2) */
451         ret = do_bsd_chflags(arg1, arg2);
452         break;
453 
454     case TARGET_FREEBSD_NR_lchflags: /* lchflags(2) */
455         ret = do_bsd_lchflags(arg1, arg2);
456         break;
457 
458     case TARGET_FREEBSD_NR_fchflags: /* fchflags(2) */
459         ret = do_bsd_fchflags(arg1, arg2);
460         break;
461 
462     case TARGET_FREEBSD_NR_chroot: /* chroot(2) */
463         ret = do_bsd_chroot(arg1);
464         break;
465 
466     case TARGET_FREEBSD_NR_flock: /* flock(2) */
467         ret = do_bsd_flock(arg1, arg2);
468         break;
469 
470     case TARGET_FREEBSD_NR_mkfifo: /* mkfifo(2) */
471         ret = do_bsd_mkfifo(arg1, arg2);
472         break;
473 
474     case TARGET_FREEBSD_NR_mkfifoat: /* mkfifoat(2) */
475         ret = do_bsd_mkfifoat(arg1, arg2, arg3);
476         break;
477 
478     case TARGET_FREEBSD_NR_pathconf: /* pathconf(2) */
479         ret = do_bsd_pathconf(arg1, arg2);
480         break;
481 
482     case TARGET_FREEBSD_NR_lpathconf: /* lpathconf(2) */
483         ret = do_bsd_lpathconf(arg1, arg2);
484         break;
485 
486     case TARGET_FREEBSD_NR_fpathconf: /* fpathconf(2) */
487         ret = do_bsd_fpathconf(arg1, arg2);
488         break;
489 
490     case TARGET_FREEBSD_NR_undelete: /* undelete(2) */
491         ret = do_bsd_undelete(arg1);
492         break;
493 
494         /*
495          * sys{ctl, arch, call}
496          */
497     case TARGET_FREEBSD_NR___sysctl: /* sysctl(3) */
498         ret = do_freebsd_sysctl(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
499         break;
500 
501     case TARGET_FREEBSD_NR___sysctlbyname: /* sysctlbyname(2) */
502         ret = do_freebsd_sysctlbyname(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
503         break;
504 
505     case TARGET_FREEBSD_NR_sysarch: /* sysarch(2) */
506         ret = do_freebsd_sysarch(cpu_env, arg1, arg2);
507         break;
508 
509     default:
510         qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);
511         ret = -TARGET_ENOSYS;
512         break;
513     }
514 
515     return ret;
516 }
517 
518 /*
519  * do_freebsd_syscall() should always have a single exit point at the end so
520  * that actions, such as logging of syscall results, can be performed. This
521  * as a wrapper around freebsd_syscall() so that actually happens. Since
522  * that is a singleton, modern compilers will inline it anyway...
523  */
524 abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1,
525                             abi_long arg2, abi_long arg3, abi_long arg4,
526                             abi_long arg5, abi_long arg6, abi_long arg7,
527                             abi_long arg8)
528 {
529     CPUState *cpu = env_cpu(cpu_env);
530     abi_long ret;
531 
532     trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8);
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     trace_guest_user_syscall_ret(cpu, num, ret);
543 
544     return ret;
545 }
546 
547 void syscall_init(void)
548 {
549 }
550