xref: /openbmc/qemu/bsd-user/freebsd/os-syscall.c (revision 25e2cfbb)
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 #include "qemu/osdep.h"
21 #include "qemu/cutils.h"
22 #include "qemu/path.h"
23 #include <sys/syscall.h>
24 #include <sys/cdefs.h>
25 #include <sys/param.h>
26 #include <sys/mount.h>
27 #include <sys/sysctl.h>
28 #include <utime.h>
29 
30 #include "include/gdbstub/syscalls.h"
31 
32 #include "qemu.h"
33 #include "signal-common.h"
34 #include "user/syscall-trace.h"
35 
36 #include "bsd-file.h"
37 #include "bsd-proc.h"
38 
39 /* I/O */
40 safe_syscall3(int, open, const char *, path, int, flags, mode_t, mode);
41 safe_syscall4(int, openat, int, fd, const char *, path, int, flags, mode_t,
42     mode);
43 
44 safe_syscall3(ssize_t, read, int, fd, void *, buf, size_t, nbytes);
45 safe_syscall4(ssize_t, pread, int, fd, void *, buf, size_t, nbytes, off_t,
46     offset);
47 safe_syscall3(ssize_t, readv, int, fd, const struct iovec *, iov, int, iovcnt);
48 safe_syscall4(ssize_t, preadv, int, fd, const struct iovec *, iov, int, iovcnt,
49     off_t, offset);
50 
51 safe_syscall3(ssize_t, write, int, fd, void *, buf, size_t, nbytes);
52 safe_syscall4(ssize_t, pwrite, int, fd, void *, buf, size_t, nbytes, off_t,
53     offset);
54 safe_syscall3(ssize_t, writev, int, fd, const struct iovec *, iov, int, iovcnt);
55 safe_syscall4(ssize_t, pwritev, int, fd, const struct iovec *, iov, int, iovcnt,
56     off_t, offset);
57 
58 void target_set_brk(abi_ulong new_brk)
59 {
60 }
61 
62 /*
63  * errno conversion.
64  */
65 abi_long get_errno(abi_long ret)
66 {
67     if (ret == -1) {
68         return -host_to_target_errno(errno);
69     } else {
70         return ret;
71     }
72 }
73 
74 int host_to_target_errno(int err)
75 {
76     /*
77      * All the BSDs have the property that the error numbers are uniform across
78      * all architectures for a given BSD, though they may vary between different
79      * BSDs.
80      */
81     return err;
82 }
83 
84 bool is_error(abi_long ret)
85 {
86     return (abi_ulong)ret >= (abi_ulong)(-4096);
87 }
88 
89 /*
90  * Unlocks a iovec. Unlike unlock_iovec, it assumes the tvec array itself is
91  * already locked from target_addr. It will be unlocked as well as all the iovec
92  * elements.
93  */
94 static void helper_unlock_iovec(struct target_iovec *target_vec,
95                                 abi_ulong target_addr, struct iovec *vec,
96                                 int count, int copy)
97 {
98     for (int i = 0; i < count; i++) {
99         abi_ulong base = tswapal(target_vec[i].iov_base);
100 
101         if (vec[i].iov_base) {
102             unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0);
103         }
104     }
105     unlock_user(target_vec, target_addr, 0);
106 }
107 
108 struct iovec *lock_iovec(int type, abi_ulong target_addr,
109         int count, int copy)
110 {
111     struct target_iovec *target_vec;
112     struct iovec *vec;
113     abi_ulong total_len, max_len;
114     int i;
115     int err = 0;
116 
117     if (count == 0) {
118         errno = 0;
119         return NULL;
120     }
121     if (count < 0 || count > IOV_MAX) {
122         errno = EINVAL;
123         return NULL;
124     }
125 
126     vec = g_try_new0(struct iovec, count);
127     if (vec == NULL) {
128         errno = ENOMEM;
129         return NULL;
130     }
131 
132     target_vec = lock_user(VERIFY_READ, target_addr,
133                            count * sizeof(struct target_iovec), 1);
134     if (target_vec == NULL) {
135         err = EFAULT;
136         goto fail2;
137     }
138 
139     max_len = 0x7fffffff & MIN(TARGET_PAGE_MASK, PAGE_MASK);
140     total_len = 0;
141 
142     for (i = 0; i < count; i++) {
143         abi_ulong base = tswapal(target_vec[i].iov_base);
144         abi_long len = tswapal(target_vec[i].iov_len);
145 
146         if (len < 0) {
147             err = EINVAL;
148             goto fail;
149         } else if (len == 0) {
150             /* Zero length pointer is ignored. */
151             vec[i].iov_base = 0;
152         } else {
153             vec[i].iov_base = lock_user(type, base, len, copy);
154             /*
155              * If the first buffer pointer is bad, this is a fault.  But
156              * subsequent bad buffers will result in a partial write; this is
157              * realized by filling the vector with null pointers and zero
158              * lengths.
159              */
160             if (!vec[i].iov_base) {
161                 if (i == 0) {
162                     err = EFAULT;
163                     goto fail;
164                 } else {
165                     /*
166                      * Fail all the subsequent addresses, they are already
167                      * zero'd.
168                      */
169                     goto out;
170                 }
171             }
172             if (len > max_len - total_len) {
173                 len = max_len - total_len;
174             }
175         }
176         vec[i].iov_len = len;
177         total_len += len;
178     }
179 out:
180     unlock_user(target_vec, target_addr, 0);
181     return vec;
182 
183 fail:
184     helper_unlock_iovec(target_vec, target_addr, vec, i, copy);
185 fail2:
186     g_free(vec);
187     errno = err;
188     return NULL;
189 }
190 
191 void unlock_iovec(struct iovec *vec, abi_ulong target_addr,
192         int count, int copy)
193 {
194     struct target_iovec *target_vec;
195 
196     target_vec = lock_user(VERIFY_READ, target_addr,
197                            count * sizeof(struct target_iovec), 1);
198     if (target_vec) {
199         helper_unlock_iovec(target_vec, target_addr, vec, count, copy);
200     }
201 
202     g_free(vec);
203 }
204 
205 /*
206  * All errnos that freebsd_syscall() returns must be -TARGET_<errcode>.
207  */
208 static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1,
209                                 abi_long arg2, abi_long arg3, abi_long arg4,
210                                 abi_long arg5, abi_long arg6, abi_long arg7,
211                                 abi_long arg8)
212 {
213     abi_long ret;
214 
215     switch (num) {
216         /*
217          * process system calls
218          */
219     case TARGET_FREEBSD_NR_exit: /* exit(2) */
220         ret = do_bsd_exit(cpu_env, arg1);
221         break;
222 
223         /*
224          * File system calls.
225          */
226     case TARGET_FREEBSD_NR_read: /* read(2) */
227         ret = do_bsd_read(arg1, arg2, arg3);
228         break;
229 
230     case TARGET_FREEBSD_NR_pread: /* pread(2) */
231         ret = do_bsd_pread(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
232         break;
233 
234     case TARGET_FREEBSD_NR_readv: /* readv(2) */
235         ret = do_bsd_readv(arg1, arg2, arg3);
236         break;
237 
238     case TARGET_FREEBSD_NR_preadv: /* preadv(2) */
239         ret = do_bsd_preadv(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
240 
241     case TARGET_FREEBSD_NR_write: /* write(2) */
242         ret = do_bsd_write(arg1, arg2, arg3);
243         break;
244 
245     case TARGET_FREEBSD_NR_pwrite: /* pwrite(2) */
246         ret = do_bsd_pwrite(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
247         break;
248 
249     case TARGET_FREEBSD_NR_writev: /* writev(2) */
250         ret = do_bsd_writev(arg1, arg2, arg3);
251         break;
252 
253     case TARGET_FREEBSD_NR_pwritev: /* pwritev(2) */
254         ret = do_bsd_pwritev(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
255         break;
256 
257     case TARGET_FREEBSD_NR_open: /* open(2) */
258         ret = do_bsd_open(arg1, arg2, arg3);
259         break;
260 
261     case TARGET_FREEBSD_NR_openat: /* openat(2) */
262         ret = do_bsd_openat(arg1, arg2, arg3, arg4);
263         break;
264 
265     case TARGET_FREEBSD_NR_close: /* close(2) */
266         ret = do_bsd_close(arg1);
267         break;
268 
269     case TARGET_FREEBSD_NR_fdatasync: /* fdatasync(2) */
270         ret = do_bsd_fdatasync(arg1);
271         break;
272 
273     case TARGET_FREEBSD_NR_fsync: /* fsync(2) */
274         ret = do_bsd_fsync(arg1);
275         break;
276 
277     case TARGET_FREEBSD_NR_freebsd12_closefrom: /* closefrom(2) */
278         ret = do_bsd_closefrom(arg1);
279         break;
280 
281     case TARGET_FREEBSD_NR_revoke: /* revoke(2) */
282         ret = do_bsd_revoke(arg1);
283         break;
284 
285     case TARGET_FREEBSD_NR_access: /* access(2) */
286         ret = do_bsd_access(arg1, arg2);
287         break;
288 
289     case TARGET_FREEBSD_NR_eaccess: /* eaccess(2) */
290         ret = do_bsd_eaccess(arg1, arg2);
291         break;
292 
293     case TARGET_FREEBSD_NR_faccessat: /* faccessat(2) */
294         ret = do_bsd_faccessat(arg1, arg2, arg3, arg4);
295         break;
296 
297     case TARGET_FREEBSD_NR_chdir: /* chdir(2) */
298         ret = do_bsd_chdir(arg1);
299         break;
300 
301     case TARGET_FREEBSD_NR_fchdir: /* fchdir(2) */
302         ret = do_bsd_fchdir(arg1);
303         break;
304 
305     case TARGET_FREEBSD_NR_rename: /* rename(2) */
306         ret = do_bsd_rename(arg1, arg2);
307         break;
308 
309     case TARGET_FREEBSD_NR_renameat: /* renameat(2) */
310         ret = do_bsd_renameat(arg1, arg2, arg3, arg4);
311         break;
312 
313     case TARGET_FREEBSD_NR_link: /* link(2) */
314         ret = do_bsd_link(arg1, arg2);
315         break;
316 
317     case TARGET_FREEBSD_NR_linkat: /* linkat(2) */
318         ret = do_bsd_linkat(arg1, arg2, arg3, arg4, arg5);
319         break;
320 
321     case TARGET_FREEBSD_NR_unlink: /* unlink(2) */
322         ret = do_bsd_unlink(arg1);
323         break;
324 
325     case TARGET_FREEBSD_NR_unlinkat: /* unlinkat(2) */
326         ret = do_bsd_unlinkat(arg1, arg2, arg3);
327         break;
328 
329     case TARGET_FREEBSD_NR_mkdir: /* mkdir(2) */
330         ret = do_bsd_mkdir(arg1, arg2);
331         break;
332 
333     case TARGET_FREEBSD_NR_mkdirat: /* mkdirat(2) */
334         ret = do_bsd_mkdirat(arg1, arg2, arg3);
335         break;
336 
337     case TARGET_FREEBSD_NR_rmdir: /* rmdir(2) (XXX no rmdirat()?) */
338         ret = do_bsd_rmdir(arg1);
339         break;
340 
341     case TARGET_FREEBSD_NR___getcwd: /* undocumented __getcwd() */
342         ret = do_bsd___getcwd(arg1, arg2);
343         break;
344 
345     case TARGET_FREEBSD_NR_dup: /* dup(2) */
346         ret = do_bsd_dup(arg1);
347         break;
348 
349     case TARGET_FREEBSD_NR_dup2: /* dup2(2) */
350         ret = do_bsd_dup2(arg1, arg2);
351         break;
352 
353     case TARGET_FREEBSD_NR_truncate: /* truncate(2) */
354         ret = do_bsd_truncate(cpu_env, arg1, arg2, arg3, arg4);
355         break;
356 
357     case TARGET_FREEBSD_NR_ftruncate: /* ftruncate(2) */
358         ret = do_bsd_ftruncate(cpu_env, arg1, arg2, arg3, arg4);
359         break;
360 
361     case TARGET_FREEBSD_NR_acct: /* acct(2) */
362         ret = do_bsd_acct(arg1);
363         break;
364 
365     case TARGET_FREEBSD_NR_sync: /* sync(2) */
366         ret = do_bsd_sync();
367         break;
368 
369     case TARGET_FREEBSD_NR_mount: /* mount(2) */
370         ret = do_bsd_mount(arg1, arg2, arg3, arg4);
371         break;
372 
373     case TARGET_FREEBSD_NR_unmount: /* unmount(2) */
374         ret = do_bsd_unmount(arg1, arg2);
375         break;
376 
377     case TARGET_FREEBSD_NR_nmount: /* nmount(2) */
378         ret = do_bsd_nmount(arg1, arg2, arg3);
379         break;
380 
381     case TARGET_FREEBSD_NR_symlink: /* symlink(2) */
382         ret = do_bsd_symlink(arg1, arg2);
383         break;
384 
385     case TARGET_FREEBSD_NR_symlinkat: /* symlinkat(2) */
386         ret = do_bsd_symlinkat(arg1, arg2, arg3);
387         break;
388 
389     case TARGET_FREEBSD_NR_readlink: /* readlink(2) */
390         ret = do_bsd_readlink(cpu_env, arg1, arg2, arg3);
391         break;
392 
393     case TARGET_FREEBSD_NR_readlinkat: /* readlinkat(2) */
394         ret = do_bsd_readlinkat(arg1, arg2, arg3, arg4);
395         break;
396 
397     case TARGET_FREEBSD_NR_chmod: /* chmod(2) */
398         ret = do_bsd_chmod(arg1, arg2);
399         break;
400 
401     case TARGET_FREEBSD_NR_fchmod: /* fchmod(2) */
402         ret = do_bsd_fchmod(arg1, arg2);
403         break;
404 
405     case TARGET_FREEBSD_NR_lchmod: /* lchmod(2) */
406         ret = do_bsd_lchmod(arg1, arg2);
407         break;
408 
409     case TARGET_FREEBSD_NR_fchmodat: /* fchmodat(2) */
410         ret = do_bsd_fchmodat(arg1, arg2, arg3, arg4);
411         break;
412 
413     case TARGET_FREEBSD_NR_freebsd11_mknod: /* mknod(2) */
414         ret = do_bsd_freebsd11_mknod(arg1, arg2, arg3);
415         break;
416 
417     case TARGET_FREEBSD_NR_freebsd11_mknodat: /* mknodat(2) */
418         ret = do_bsd_freebsd11_mknodat(arg1, arg2, arg3, arg4);
419         break;
420 
421     case TARGET_FREEBSD_NR_mknodat: /* mknodat(2) */
422         ret = do_bsd_mknodat(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
423         break;
424 
425     case TARGET_FREEBSD_NR_chown: /* chown(2) */
426         ret = do_bsd_chown(arg1, arg2, arg3);
427         break;
428 
429     case TARGET_FREEBSD_NR_fchown: /* fchown(2) */
430         ret = do_bsd_fchown(arg1, arg2, arg3);
431         break;
432 
433     case TARGET_FREEBSD_NR_lchown: /* lchown(2) */
434         ret = do_bsd_lchown(arg1, arg2, arg3);
435         break;
436 
437     case TARGET_FREEBSD_NR_fchownat: /* fchownat(2) */
438         ret = do_bsd_fchownat(arg1, arg2, arg3, arg4, arg5);
439         break;
440 
441     case TARGET_FREEBSD_NR_chflags: /* chflags(2) */
442         ret = do_bsd_chflags(arg1, arg2);
443         break;
444 
445     case TARGET_FREEBSD_NR_lchflags: /* lchflags(2) */
446         ret = do_bsd_lchflags(arg1, arg2);
447         break;
448 
449     case TARGET_FREEBSD_NR_fchflags: /* fchflags(2) */
450         ret = do_bsd_fchflags(arg1, arg2);
451         break;
452 
453     case TARGET_FREEBSD_NR_chroot: /* chroot(2) */
454         ret = do_bsd_chroot(arg1);
455         break;
456 
457     case TARGET_FREEBSD_NR_flock: /* flock(2) */
458         ret = do_bsd_flock(arg1, arg2);
459         break;
460 
461     case TARGET_FREEBSD_NR_mkfifo: /* mkfifo(2) */
462         ret = do_bsd_mkfifo(arg1, arg2);
463         break;
464 
465     case TARGET_FREEBSD_NR_mkfifoat: /* mkfifoat(2) */
466         ret = do_bsd_mkfifoat(arg1, arg2, arg3);
467         break;
468 
469     case TARGET_FREEBSD_NR_pathconf: /* pathconf(2) */
470         ret = do_bsd_pathconf(arg1, arg2);
471         break;
472 
473     case TARGET_FREEBSD_NR_lpathconf: /* lpathconf(2) */
474         ret = do_bsd_lpathconf(arg1, arg2);
475         break;
476 
477     case TARGET_FREEBSD_NR_fpathconf: /* fpathconf(2) */
478         ret = do_bsd_fpathconf(arg1, arg2);
479         break;
480 
481     case TARGET_FREEBSD_NR_undelete: /* undelete(2) */
482         ret = do_bsd_undelete(arg1);
483         break;
484 
485         /*
486          * sys{ctl, arch, call}
487          */
488     case TARGET_FREEBSD_NR___sysctl: /* sysctl(3) */
489         ret = do_freebsd_sysctl(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
490         break;
491 
492     case TARGET_FREEBSD_NR___sysctlbyname: /* sysctlbyname(2) */
493         ret = do_freebsd_sysctlbyname(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
494         break;
495 
496     case TARGET_FREEBSD_NR_sysarch: /* sysarch(2) */
497         ret = do_freebsd_sysarch(cpu_env, arg1, arg2);
498         break;
499 
500     default:
501         qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);
502         ret = -TARGET_ENOSYS;
503         break;
504     }
505 
506     return ret;
507 }
508 
509 /*
510  * do_freebsd_syscall() should always have a single exit point at the end so
511  * that actions, such as logging of syscall results, can be performed. This
512  * as a wrapper around freebsd_syscall() so that actually happens. Since
513  * that is a singleton, modern compilers will inline it anyway...
514  */
515 abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1,
516                             abi_long arg2, abi_long arg3, abi_long arg4,
517                             abi_long arg5, abi_long arg6, abi_long arg7,
518                             abi_long arg8)
519 {
520     abi_long ret;
521 
522     if (do_strace) {
523         print_freebsd_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);
524     }
525 
526     ret = freebsd_syscall(cpu_env, num, arg1, arg2, arg3, arg4, arg5, arg6,
527                           arg7, arg8);
528     if (do_strace) {
529         print_freebsd_syscall_ret(num, ret);
530     }
531 
532     return ret;
533 }
534 
535 void syscall_init(void)
536 {
537 }
538