1 /*-
2 * Copyright (c) 2015 Nuxi, https://nuxi.nl/
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD: stable/12/sys/compat/cloudabi/cloudabi_fd.c 351142 2019-08-16 21:01:35Z kevans $");
28
29 #include <sys/param.h>
30 #include <sys/capsicum.h>
31 #include <sys/filedesc.h>
32 #include <sys/proc.h>
33 #include <sys/mman.h>
34 #include <sys/socketvar.h>
35 #include <sys/syscallsubr.h>
36 #include <sys/sysproto.h>
37 #include <sys/systm.h>
38 #include <sys/unistd.h>
39 #include <sys/vnode.h>
40
41 #include <contrib/cloudabi/cloudabi_types_common.h>
42
43 #include <compat/cloudabi/cloudabi_proto.h>
44 #include <compat/cloudabi/cloudabi_util.h>
45
46 /* Translation between CloudABI and Capsicum rights. */
47 #define RIGHTS_MAPPINGS \
48 MAPPING(CLOUDABI_RIGHT_FD_DATASYNC, CAP_FSYNC) \
49 MAPPING(CLOUDABI_RIGHT_FD_READ, CAP_READ) \
50 MAPPING(CLOUDABI_RIGHT_FD_SEEK, CAP_SEEK) \
51 MAPPING(CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS, CAP_FCNTL) \
52 MAPPING(CLOUDABI_RIGHT_FD_SYNC, CAP_FSYNC) \
53 MAPPING(CLOUDABI_RIGHT_FD_TELL, CAP_SEEK_TELL) \
54 MAPPING(CLOUDABI_RIGHT_FD_WRITE, CAP_WRITE) \
55 MAPPING(CLOUDABI_RIGHT_FILE_ADVISE) \
56 MAPPING(CLOUDABI_RIGHT_FILE_ALLOCATE, CAP_WRITE) \
57 MAPPING(CLOUDABI_RIGHT_FILE_CREATE_DIRECTORY, CAP_MKDIRAT) \
58 MAPPING(CLOUDABI_RIGHT_FILE_CREATE_FILE, CAP_CREATE) \
59 MAPPING(CLOUDABI_RIGHT_FILE_LINK_SOURCE, CAP_LINKAT_SOURCE) \
60 MAPPING(CLOUDABI_RIGHT_FILE_LINK_TARGET, CAP_LINKAT_TARGET) \
61 MAPPING(CLOUDABI_RIGHT_FILE_OPEN, CAP_LOOKUP) \
62 MAPPING(CLOUDABI_RIGHT_FILE_READDIR, CAP_READ) \
63 MAPPING(CLOUDABI_RIGHT_FILE_READLINK, CAP_LOOKUP) \
64 MAPPING(CLOUDABI_RIGHT_FILE_RENAME_SOURCE, CAP_RENAMEAT_SOURCE) \
65 MAPPING(CLOUDABI_RIGHT_FILE_RENAME_TARGET, CAP_RENAMEAT_TARGET) \
66 MAPPING(CLOUDABI_RIGHT_FILE_STAT_FGET, CAP_FSTAT) \
67 MAPPING(CLOUDABI_RIGHT_FILE_STAT_FPUT_SIZE, CAP_FTRUNCATE) \
68 MAPPING(CLOUDABI_RIGHT_FILE_STAT_FPUT_TIMES, CAP_FUTIMES) \
69 MAPPING(CLOUDABI_RIGHT_FILE_STAT_GET, CAP_FSTATAT) \
70 MAPPING(CLOUDABI_RIGHT_FILE_STAT_PUT_TIMES, CAP_FUTIMESAT) \
71 MAPPING(CLOUDABI_RIGHT_FILE_SYMLINK, CAP_SYMLINKAT) \
72 MAPPING(CLOUDABI_RIGHT_FILE_UNLINK, CAP_UNLINKAT) \
73 MAPPING(CLOUDABI_RIGHT_MEM_MAP, CAP_MMAP) \
74 MAPPING(CLOUDABI_RIGHT_MEM_MAP_EXEC, CAP_MMAP_X) \
75 MAPPING(CLOUDABI_RIGHT_POLL_FD_READWRITE, CAP_EVENT) \
76 MAPPING(CLOUDABI_RIGHT_POLL_PROC_TERMINATE, CAP_EVENT) \
77 MAPPING(CLOUDABI_RIGHT_PROC_EXEC, CAP_FEXECVE) \
78 MAPPING(CLOUDABI_RIGHT_SOCK_SHUTDOWN, CAP_SHUTDOWN) \
79
80 int
cloudabi_sys_fd_close(struct thread * td,struct cloudabi_sys_fd_close_args * uap)81 cloudabi_sys_fd_close(struct thread *td, struct cloudabi_sys_fd_close_args *uap)
82 {
83
84 return (kern_close(td, uap->fd));
85 }
86
87 int
cloudabi_sys_fd_create1(struct thread * td,struct cloudabi_sys_fd_create1_args * uap)88 cloudabi_sys_fd_create1(struct thread *td,
89 struct cloudabi_sys_fd_create1_args *uap)
90 {
91 struct filecaps fcaps = {};
92
93 switch (uap->type) {
94 case CLOUDABI_FILETYPE_SHARED_MEMORY:
95 cap_rights_init(&fcaps.fc_rights, CAP_FSTAT, CAP_FTRUNCATE,
96 CAP_MMAP_RWX);
97 return (kern_shm_open(td, SHM_ANON, O_RDWR | O_CLOEXEC, 0,
98 &fcaps));
99 default:
100 return (EINVAL);
101 }
102 }
103
104 int
cloudabi_sys_fd_create2(struct thread * td,struct cloudabi_sys_fd_create2_args * uap)105 cloudabi_sys_fd_create2(struct thread *td,
106 struct cloudabi_sys_fd_create2_args *uap)
107 {
108 int fds[2];
109 int error, type;
110
111 switch (uap->type) {
112 case CLOUDABI_FILETYPE_SOCKET_DGRAM:
113 type = SOCK_DGRAM;
114 break;
115 case CLOUDABI_FILETYPE_SOCKET_STREAM:
116 type = SOCK_STREAM;
117 break;
118 default:
119 return (EINVAL);
120 }
121
122 error = kern_socketpair(td, AF_UNIX, type, 0, fds);
123 if (error == 0) {
124 td->td_retval[0] = fds[0];
125 td->td_retval[1] = fds[1];
126 }
127 return (0);
128 }
129
130 int
cloudabi_sys_fd_datasync(struct thread * td,struct cloudabi_sys_fd_datasync_args * uap)131 cloudabi_sys_fd_datasync(struct thread *td,
132 struct cloudabi_sys_fd_datasync_args *uap)
133 {
134
135 return (kern_fsync(td, uap->fd, false));
136 }
137
138 int
cloudabi_sys_fd_dup(struct thread * td,struct cloudabi_sys_fd_dup_args * uap)139 cloudabi_sys_fd_dup(struct thread *td, struct cloudabi_sys_fd_dup_args *uap)
140 {
141
142 return (kern_dup(td, FDDUP_NORMAL, 0, uap->from, 0));
143 }
144
145 int
cloudabi_sys_fd_replace(struct thread * td,struct cloudabi_sys_fd_replace_args * uap)146 cloudabi_sys_fd_replace(struct thread *td,
147 struct cloudabi_sys_fd_replace_args *uap)
148 {
149 int error;
150
151 /*
152 * CloudABI's equivalent to dup2(). CloudABI processes should
153 * not depend on hardcoded file descriptor layouts, but simply
154 * use the file descriptor numbers that are allocated by the
155 * kernel. Duplicating file descriptors to arbitrary numbers
156 * should not be done.
157 *
158 * Invoke kern_dup() with FDDUP_MUSTREPLACE, so that we return
159 * EBADF when duplicating to a nonexistent file descriptor. Also
160 * clear the return value, as this system call yields no return
161 * value.
162 */
163 error = kern_dup(td, FDDUP_MUSTREPLACE, 0, uap->from, uap->to);
164 td->td_retval[0] = 0;
165 return (error);
166 }
167
168 int
cloudabi_sys_fd_seek(struct thread * td,struct cloudabi_sys_fd_seek_args * uap)169 cloudabi_sys_fd_seek(struct thread *td, struct cloudabi_sys_fd_seek_args *uap)
170 {
171 int whence;
172
173 switch (uap->whence) {
174 case CLOUDABI_WHENCE_CUR:
175 whence = SEEK_CUR;
176 break;
177 case CLOUDABI_WHENCE_END:
178 whence = SEEK_END;
179 break;
180 case CLOUDABI_WHENCE_SET:
181 whence = SEEK_SET;
182 break;
183 default:
184 return (EINVAL);
185 }
186
187 return (kern_lseek(td, uap->fd, uap->offset, whence));
188 }
189
190 /* Converts a file descriptor to a CloudABI file descriptor type. */
191 cloudabi_filetype_t
cloudabi_convert_filetype(const struct file * fp)192 cloudabi_convert_filetype(const struct file *fp)
193 {
194 struct socket *so;
195 struct vnode *vp;
196
197 switch (fp->f_type) {
198 case DTYPE_FIFO:
199 return (CLOUDABI_FILETYPE_SOCKET_STREAM);
200 case DTYPE_PIPE:
201 return (CLOUDABI_FILETYPE_SOCKET_STREAM);
202 case DTYPE_PROCDESC:
203 return (CLOUDABI_FILETYPE_PROCESS);
204 case DTYPE_SHM:
205 return (CLOUDABI_FILETYPE_SHARED_MEMORY);
206 case DTYPE_SOCKET:
207 so = fp->f_data;
208 switch (so->so_type) {
209 case SOCK_DGRAM:
210 return (CLOUDABI_FILETYPE_SOCKET_DGRAM);
211 case SOCK_STREAM:
212 return (CLOUDABI_FILETYPE_SOCKET_STREAM);
213 default:
214 return (CLOUDABI_FILETYPE_UNKNOWN);
215 }
216 case DTYPE_VNODE:
217 vp = fp->f_vnode;
218 switch (vp->v_type) {
219 case VBLK:
220 return (CLOUDABI_FILETYPE_BLOCK_DEVICE);
221 case VCHR:
222 return (CLOUDABI_FILETYPE_CHARACTER_DEVICE);
223 case VDIR:
224 return (CLOUDABI_FILETYPE_DIRECTORY);
225 case VFIFO:
226 return (CLOUDABI_FILETYPE_SOCKET_STREAM);
227 case VLNK:
228 return (CLOUDABI_FILETYPE_SYMBOLIC_LINK);
229 case VREG:
230 return (CLOUDABI_FILETYPE_REGULAR_FILE);
231 case VSOCK:
232 return (CLOUDABI_FILETYPE_SOCKET_STREAM);
233 default:
234 return (CLOUDABI_FILETYPE_UNKNOWN);
235 }
236 default:
237 return (CLOUDABI_FILETYPE_UNKNOWN);
238 }
239 }
240
241 /* Removes rights that conflict with the file descriptor type. */
242 void
cloudabi_remove_conflicting_rights(cloudabi_filetype_t filetype,cloudabi_rights_t * base,cloudabi_rights_t * inheriting)243 cloudabi_remove_conflicting_rights(cloudabi_filetype_t filetype,
244 cloudabi_rights_t *base, cloudabi_rights_t *inheriting)
245 {
246
247 /*
248 * CloudABI has a small number of additional rights bits to
249 * disambiguate between multiple purposes. Remove the bits that
250 * don't apply to the type of the file descriptor.
251 *
252 * As file descriptor access modes (O_ACCMODE) has been fully
253 * replaced by rights bits, CloudABI distinguishes between
254 * rights that apply to the file descriptor itself (base) versus
255 * rights of new file descriptors derived from them
256 * (inheriting). The code below approximates the pair by
257 * decomposing depending on the file descriptor type.
258 *
259 * We need to be somewhat accurate about which actions can
260 * actually be performed on the file descriptor, as functions
261 * like fcntl(fd, F_GETFL) are emulated on top of this.
262 */
263 switch (filetype) {
264 case CLOUDABI_FILETYPE_DIRECTORY:
265 *base &= CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS |
266 CLOUDABI_RIGHT_FD_SYNC | CLOUDABI_RIGHT_FILE_ADVISE |
267 CLOUDABI_RIGHT_FILE_CREATE_DIRECTORY |
268 CLOUDABI_RIGHT_FILE_CREATE_FILE |
269 CLOUDABI_RIGHT_FILE_LINK_SOURCE |
270 CLOUDABI_RIGHT_FILE_LINK_TARGET |
271 CLOUDABI_RIGHT_FILE_OPEN |
272 CLOUDABI_RIGHT_FILE_READDIR |
273 CLOUDABI_RIGHT_FILE_READLINK |
274 CLOUDABI_RIGHT_FILE_RENAME_SOURCE |
275 CLOUDABI_RIGHT_FILE_RENAME_TARGET |
276 CLOUDABI_RIGHT_FILE_STAT_FGET |
277 CLOUDABI_RIGHT_FILE_STAT_FPUT_TIMES |
278 CLOUDABI_RIGHT_FILE_STAT_GET |
279 CLOUDABI_RIGHT_FILE_STAT_PUT_TIMES |
280 CLOUDABI_RIGHT_FILE_SYMLINK |
281 CLOUDABI_RIGHT_FILE_UNLINK |
282 CLOUDABI_RIGHT_POLL_FD_READWRITE;
283 *inheriting &= CLOUDABI_RIGHT_FD_DATASYNC |
284 CLOUDABI_RIGHT_FD_READ |
285 CLOUDABI_RIGHT_FD_SEEK |
286 CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS |
287 CLOUDABI_RIGHT_FD_SYNC |
288 CLOUDABI_RIGHT_FD_TELL |
289 CLOUDABI_RIGHT_FD_WRITE |
290 CLOUDABI_RIGHT_FILE_ADVISE |
291 CLOUDABI_RIGHT_FILE_ALLOCATE |
292 CLOUDABI_RIGHT_FILE_CREATE_DIRECTORY |
293 CLOUDABI_RIGHT_FILE_CREATE_FILE |
294 CLOUDABI_RIGHT_FILE_LINK_SOURCE |
295 CLOUDABI_RIGHT_FILE_LINK_TARGET |
296 CLOUDABI_RIGHT_FILE_OPEN |
297 CLOUDABI_RIGHT_FILE_READDIR |
298 CLOUDABI_RIGHT_FILE_READLINK |
299 CLOUDABI_RIGHT_FILE_RENAME_SOURCE |
300 CLOUDABI_RIGHT_FILE_RENAME_TARGET |
301 CLOUDABI_RIGHT_FILE_STAT_FGET |
302 CLOUDABI_RIGHT_FILE_STAT_FPUT_SIZE |
303 CLOUDABI_RIGHT_FILE_STAT_FPUT_TIMES |
304 CLOUDABI_RIGHT_FILE_STAT_GET |
305 CLOUDABI_RIGHT_FILE_STAT_PUT_TIMES |
306 CLOUDABI_RIGHT_FILE_SYMLINK |
307 CLOUDABI_RIGHT_FILE_UNLINK |
308 CLOUDABI_RIGHT_MEM_MAP |
309 CLOUDABI_RIGHT_MEM_MAP_EXEC |
310 CLOUDABI_RIGHT_POLL_FD_READWRITE |
311 CLOUDABI_RIGHT_PROC_EXEC;
312 break;
313 case CLOUDABI_FILETYPE_PROCESS:
314 *base &= ~(CLOUDABI_RIGHT_FILE_ADVISE |
315 CLOUDABI_RIGHT_POLL_FD_READWRITE);
316 *inheriting = 0;
317 break;
318 case CLOUDABI_FILETYPE_REGULAR_FILE:
319 *base &= CLOUDABI_RIGHT_FD_DATASYNC |
320 CLOUDABI_RIGHT_FD_READ |
321 CLOUDABI_RIGHT_FD_SEEK |
322 CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS |
323 CLOUDABI_RIGHT_FD_SYNC |
324 CLOUDABI_RIGHT_FD_TELL |
325 CLOUDABI_RIGHT_FD_WRITE |
326 CLOUDABI_RIGHT_FILE_ADVISE |
327 CLOUDABI_RIGHT_FILE_ALLOCATE |
328 CLOUDABI_RIGHT_FILE_STAT_FGET |
329 CLOUDABI_RIGHT_FILE_STAT_FPUT_SIZE |
330 CLOUDABI_RIGHT_FILE_STAT_FPUT_TIMES |
331 CLOUDABI_RIGHT_MEM_MAP |
332 CLOUDABI_RIGHT_MEM_MAP_EXEC |
333 CLOUDABI_RIGHT_POLL_FD_READWRITE |
334 CLOUDABI_RIGHT_PROC_EXEC;
335 *inheriting = 0;
336 break;
337 case CLOUDABI_FILETYPE_SHARED_MEMORY:
338 *base &= ~(CLOUDABI_RIGHT_FD_SEEK |
339 CLOUDABI_RIGHT_FD_TELL |
340 CLOUDABI_RIGHT_FILE_ADVISE |
341 CLOUDABI_RIGHT_FILE_ALLOCATE |
342 CLOUDABI_RIGHT_FILE_READDIR);
343 *inheriting = 0;
344 break;
345 case CLOUDABI_FILETYPE_SOCKET_DGRAM:
346 case CLOUDABI_FILETYPE_SOCKET_STREAM:
347 *base &= CLOUDABI_RIGHT_FD_READ |
348 CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS |
349 CLOUDABI_RIGHT_FD_WRITE |
350 CLOUDABI_RIGHT_FILE_STAT_FGET |
351 CLOUDABI_RIGHT_POLL_FD_READWRITE |
352 CLOUDABI_RIGHT_SOCK_SHUTDOWN;
353 break;
354 default:
355 *inheriting = 0;
356 break;
357 }
358 }
359
360 /* Converts FreeBSD's Capsicum rights to CloudABI's set of rights. */
361 static void
convert_capabilities(const cap_rights_t * capabilities,cloudabi_filetype_t filetype,cloudabi_rights_t * base,cloudabi_rights_t * inheriting)362 convert_capabilities(const cap_rights_t *capabilities,
363 cloudabi_filetype_t filetype, cloudabi_rights_t *base,
364 cloudabi_rights_t *inheriting)
365 {
366 cloudabi_rights_t rights;
367
368 /* Convert FreeBSD bits to CloudABI bits. */
369 rights = 0;
370 #define MAPPING(cloudabi, ...) do { \
371 if (cap_rights_is_set(capabilities, ##__VA_ARGS__)) \
372 rights |= (cloudabi); \
373 } while (0);
374 RIGHTS_MAPPINGS
375 #undef MAPPING
376
377 *base = rights;
378 *inheriting = rights;
379 cloudabi_remove_conflicting_rights(filetype, base, inheriting);
380 }
381
382 int
cloudabi_sys_fd_stat_get(struct thread * td,struct cloudabi_sys_fd_stat_get_args * uap)383 cloudabi_sys_fd_stat_get(struct thread *td,
384 struct cloudabi_sys_fd_stat_get_args *uap)
385 {
386 cloudabi_fdstat_t fsb = {0};
387 struct file *fp;
388 cap_rights_t rights;
389 struct filecaps fcaps;
390 int error, oflags;
391
392 /* Obtain file descriptor properties. */
393 error = fget_cap(td, uap->fd, cap_rights_init(&rights), &fp,
394 &fcaps);
395 if (error != 0)
396 return (error);
397 oflags = OFLAGS(fp->f_flag);
398 fsb.fs_filetype = cloudabi_convert_filetype(fp);
399 fdrop(fp, td);
400
401 /* Convert file descriptor flags. */
402 if (oflags & O_APPEND)
403 fsb.fs_flags |= CLOUDABI_FDFLAG_APPEND;
404 if (oflags & O_NONBLOCK)
405 fsb.fs_flags |= CLOUDABI_FDFLAG_NONBLOCK;
406 if (oflags & O_SYNC)
407 fsb.fs_flags |= CLOUDABI_FDFLAG_SYNC;
408
409 /* Convert capabilities to CloudABI rights. */
410 convert_capabilities(&fcaps.fc_rights, fsb.fs_filetype,
411 &fsb.fs_rights_base, &fsb.fs_rights_inheriting);
412 filecaps_free(&fcaps);
413 return (copyout(&fsb, (void *)uap->buf, sizeof(fsb)));
414 }
415
416 /* Converts CloudABI rights to a set of Capsicum capabilities. */
417 int
cloudabi_convert_rights(cloudabi_rights_t in,cap_rights_t * out)418 cloudabi_convert_rights(cloudabi_rights_t in, cap_rights_t *out)
419 {
420
421 cap_rights_init(out);
422 #define MAPPING(cloudabi, ...) do { \
423 if (in & (cloudabi)) { \
424 cap_rights_set(out, ##__VA_ARGS__); \
425 in &= ~(cloudabi); \
426 } \
427 } while (0);
428 RIGHTS_MAPPINGS
429 #undef MAPPING
430 if (in != 0)
431 return (ENOTCAPABLE);
432 return (0);
433 }
434
435 int
cloudabi_sys_fd_stat_put(struct thread * td,struct cloudabi_sys_fd_stat_put_args * uap)436 cloudabi_sys_fd_stat_put(struct thread *td,
437 struct cloudabi_sys_fd_stat_put_args *uap)
438 {
439 cloudabi_fdstat_t fsb;
440 cap_rights_t rights;
441 int error, oflags;
442
443 error = copyin(uap->buf, &fsb, sizeof(fsb));
444 if (error != 0)
445 return (error);
446
447 if (uap->flags == CLOUDABI_FDSTAT_FLAGS) {
448 /* Convert flags. */
449 oflags = 0;
450 if (fsb.fs_flags & CLOUDABI_FDFLAG_APPEND)
451 oflags |= O_APPEND;
452 if (fsb.fs_flags & CLOUDABI_FDFLAG_NONBLOCK)
453 oflags |= O_NONBLOCK;
454 if (fsb.fs_flags & (CLOUDABI_FDFLAG_SYNC |
455 CLOUDABI_FDFLAG_DSYNC | CLOUDABI_FDFLAG_RSYNC))
456 oflags |= O_SYNC;
457 return (kern_fcntl(td, uap->fd, F_SETFL, oflags));
458 } else if (uap->flags == CLOUDABI_FDSTAT_RIGHTS) {
459 /* Convert rights. */
460 error = cloudabi_convert_rights(
461 fsb.fs_rights_base | fsb.fs_rights_inheriting, &rights);
462 if (error != 0)
463 return (error);
464 return (kern_cap_rights_limit(td, uap->fd, &rights));
465 }
466 return (EINVAL);
467 }
468
469 int
cloudabi_sys_fd_sync(struct thread * td,struct cloudabi_sys_fd_sync_args * uap)470 cloudabi_sys_fd_sync(struct thread *td, struct cloudabi_sys_fd_sync_args *uap)
471 {
472
473 return (kern_fsync(td, uap->fd, true));
474 }
475