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10#include <linux/fs.h>
11#include <linux/slab.h>
12#include <linux/file.h>
13#include <linux/xattr.h>
14#include <linux/mount.h>
15#include <linux/namei.h>
16#include <linux/security.h>
17#include <linux/evm.h>
18#include <linux/syscalls.h>
19#include <linux/export.h>
20#include <linux/fsnotify.h>
21#include <linux/audit.h>
22#include <linux/vmalloc.h>
23#include <linux/posix_acl_xattr.h>
24
25#include <asm/uaccess.h>
26
27
28
29
30
31static int
32xattr_permission(struct inode *inode, const char *name, int mask)
33{
34
35
36
37
38 if (mask & MAY_WRITE) {
39 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
40 return -EPERM;
41 }
42
43
44
45
46
47 if (!strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) ||
48 !strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
49 return 0;
50
51
52
53
54 if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) {
55 if (!capable(CAP_SYS_ADMIN))
56 return (mask & MAY_WRITE) ? -EPERM : -ENODATA;
57 return 0;
58 }
59
60
61
62
63
64
65 if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) {
66 if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
67 return (mask & MAY_WRITE) ? -EPERM : -ENODATA;
68 if (S_ISDIR(inode->i_mode) && (inode->i_mode & S_ISVTX) &&
69 (mask & MAY_WRITE) && !inode_owner_or_capable(inode))
70 return -EPERM;
71 }
72
73 return inode_permission(inode, mask);
74}
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92int __vfs_setxattr_noperm(struct dentry *dentry, const char *name,
93 const void *value, size_t size, int flags)
94{
95 struct inode *inode = dentry->d_inode;
96 int error = -EOPNOTSUPP;
97 int issec = !strncmp(name, XATTR_SECURITY_PREFIX,
98 XATTR_SECURITY_PREFIX_LEN);
99
100 if (issec)
101 inode->i_flags &= ~S_NOSEC;
102 if (inode->i_op->setxattr) {
103 error = inode->i_op->setxattr(dentry, name, value, size, flags);
104 if (!error) {
105 fsnotify_xattr(dentry);
106 security_inode_post_setxattr(dentry, name, value,
107 size, flags);
108 }
109 } else if (issec) {
110 const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
111 error = security_inode_setsecurity(inode, suffix, value,
112 size, flags);
113 if (!error)
114 fsnotify_xattr(dentry);
115 }
116
117 return error;
118}
119
120
121int
122vfs_setxattr(struct dentry *dentry, const char *name, const void *value,
123 size_t size, int flags)
124{
125 struct inode *inode = dentry->d_inode;
126 int error;
127
128 error = xattr_permission(inode, name, MAY_WRITE);
129 if (error)
130 return error;
131
132 mutex_lock(&inode->i_mutex);
133 error = security_inode_setxattr(dentry, name, value, size, flags);
134 if (error)
135 goto out;
136
137 error = __vfs_setxattr_noperm(dentry, name, value, size, flags);
138
139out:
140 mutex_unlock(&inode->i_mutex);
141 return error;
142}
143EXPORT_SYMBOL_GPL(vfs_setxattr);
144
145ssize_t
146xattr_getsecurity(struct inode *inode, const char *name, void *value,
147 size_t size)
148{
149 void *buffer = NULL;
150 ssize_t len;
151
152 if (!value || !size) {
153 len = security_inode_getsecurity(inode, name, &buffer, false);
154 goto out_noalloc;
155 }
156
157 len = security_inode_getsecurity(inode, name, &buffer, true);
158 if (len < 0)
159 return len;
160 if (size < len) {
161 len = -ERANGE;
162 goto out;
163 }
164 memcpy(value, buffer, len);
165out:
166 security_release_secctx(buffer, len);
167out_noalloc:
168 return len;
169}
170EXPORT_SYMBOL_GPL(xattr_getsecurity);
171
172
173
174
175
176
177
178
179
180ssize_t
181vfs_getxattr_alloc(struct dentry *dentry, const char *name, char **xattr_value,
182 size_t xattr_size, gfp_t flags)
183{
184 struct inode *inode = dentry->d_inode;
185 char *value = *xattr_value;
186 int error;
187
188 error = xattr_permission(inode, name, MAY_READ);
189 if (error)
190 return error;
191
192 if (!inode->i_op->getxattr)
193 return -EOPNOTSUPP;
194
195 error = inode->i_op->getxattr(dentry, name, NULL, 0);
196 if (error < 0)
197 return error;
198
199 if (!value || (error > xattr_size)) {
200 value = krealloc(*xattr_value, error + 1, flags);
201 if (!value)
202 return -ENOMEM;
203 memset(value, 0, error + 1);
204 }
205
206 error = inode->i_op->getxattr(dentry, name, value, error);
207 *xattr_value = value;
208 return error;
209}
210
211
212int vfs_xattr_cmp(struct dentry *dentry, const char *xattr_name,
213 const char *value, size_t size, gfp_t flags)
214{
215 char *xattr_value = NULL;
216 int rc;
217
218 rc = vfs_getxattr_alloc(dentry, xattr_name, &xattr_value, 0, flags);
219 if (rc < 0)
220 return rc;
221
222 if ((rc != size) || (memcmp(xattr_value, value, rc) != 0))
223 rc = -EINVAL;
224 else
225 rc = 0;
226 kfree(xattr_value);
227 return rc;
228}
229
230ssize_t
231vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size)
232{
233 struct inode *inode = dentry->d_inode;
234 int error;
235
236 error = xattr_permission(inode, name, MAY_READ);
237 if (error)
238 return error;
239
240 error = security_inode_getxattr(dentry, name);
241 if (error)
242 return error;
243
244 if (!strncmp(name, XATTR_SECURITY_PREFIX,
245 XATTR_SECURITY_PREFIX_LEN)) {
246 const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
247 int ret = xattr_getsecurity(inode, suffix, value, size);
248
249
250
251
252 if (ret == -EOPNOTSUPP)
253 goto nolsm;
254 return ret;
255 }
256nolsm:
257 if (inode->i_op->getxattr)
258 error = inode->i_op->getxattr(dentry, name, value, size);
259 else
260 error = -EOPNOTSUPP;
261
262 return error;
263}
264EXPORT_SYMBOL_GPL(vfs_getxattr);
265
266ssize_t
267vfs_listxattr(struct dentry *d, char *list, size_t size)
268{
269 ssize_t error;
270
271 error = security_inode_listxattr(d);
272 if (error)
273 return error;
274 error = -EOPNOTSUPP;
275 if (d->d_inode->i_op->listxattr) {
276 error = d->d_inode->i_op->listxattr(d, list, size);
277 } else {
278 error = security_inode_listsecurity(d->d_inode, list, size);
279 if (size && error > size)
280 error = -ERANGE;
281 }
282 return error;
283}
284EXPORT_SYMBOL_GPL(vfs_listxattr);
285
286int
287vfs_removexattr(struct dentry *dentry, const char *name)
288{
289 struct inode *inode = dentry->d_inode;
290 int error;
291
292 if (!inode->i_op->removexattr)
293 return -EOPNOTSUPP;
294
295 error = xattr_permission(inode, name, MAY_WRITE);
296 if (error)
297 return error;
298
299 mutex_lock(&inode->i_mutex);
300 error = security_inode_removexattr(dentry, name);
301 if (error) {
302 mutex_unlock(&inode->i_mutex);
303 return error;
304 }
305
306 error = inode->i_op->removexattr(dentry, name);
307 mutex_unlock(&inode->i_mutex);
308
309 if (!error) {
310 fsnotify_xattr(dentry);
311 evm_inode_post_removexattr(dentry, name);
312 }
313 return error;
314}
315EXPORT_SYMBOL_GPL(vfs_removexattr);
316
317
318
319
320
321static long
322setxattr(struct dentry *d, const char __user *name, const void __user *value,
323 size_t size, int flags)
324{
325 int error;
326 void *kvalue = NULL;
327 void *vvalue = NULL;
328 char kname[XATTR_NAME_MAX + 1];
329
330 if (flags & ~(XATTR_CREATE|XATTR_REPLACE))
331 return -EINVAL;
332
333 error = strncpy_from_user(kname, name, sizeof(kname));
334 if (error == 0 || error == sizeof(kname))
335 error = -ERANGE;
336 if (error < 0)
337 return error;
338
339 if (size) {
340 if (size > XATTR_SIZE_MAX)
341 return -E2BIG;
342 kvalue = kmalloc(size, GFP_KERNEL | __GFP_NOWARN);
343 if (!kvalue) {
344 vvalue = vmalloc(size);
345 if (!vvalue)
346 return -ENOMEM;
347 kvalue = vvalue;
348 }
349 if (copy_from_user(kvalue, value, size)) {
350 error = -EFAULT;
351 goto out;
352 }
353 if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
354 (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0))
355 posix_acl_fix_xattr_from_user(kvalue, size);
356 }
357
358 error = vfs_setxattr(d, kname, kvalue, size, flags);
359out:
360 if (vvalue)
361 vfree(vvalue);
362 else
363 kfree(kvalue);
364 return error;
365}
366
367SYSCALL_DEFINE5(setxattr, const char __user *, pathname,
368 const char __user *, name, const void __user *, value,
369 size_t, size, int, flags)
370{
371 struct path path;
372 int error;
373
374 error = user_path(pathname, &path);
375 if (error)
376 return error;
377 error = mnt_want_write(path.mnt);
378 if (!error) {
379 error = setxattr(path.dentry, name, value, size, flags);
380 mnt_drop_write(path.mnt);
381 }
382 path_put(&path);
383 return error;
384}
385
386SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname,
387 const char __user *, name, const void __user *, value,
388 size_t, size, int, flags)
389{
390 struct path path;
391 int error;
392
393 error = user_lpath(pathname, &path);
394 if (error)
395 return error;
396 error = mnt_want_write(path.mnt);
397 if (!error) {
398 error = setxattr(path.dentry, name, value, size, flags);
399 mnt_drop_write(path.mnt);
400 }
401 path_put(&path);
402 return error;
403}
404
405SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name,
406 const void __user *,value, size_t, size, int, flags)
407{
408 struct fd f = fdget(fd);
409 struct dentry *dentry;
410 int error = -EBADF;
411
412 if (!f.file)
413 return error;
414 dentry = f.file->f_path.dentry;
415 audit_inode(NULL, dentry, 0);
416 error = mnt_want_write_file(f.file);
417 if (!error) {
418 error = setxattr(dentry, name, value, size, flags);
419 mnt_drop_write_file(f.file);
420 }
421 fdput(f);
422 return error;
423}
424
425
426
427
428static ssize_t
429getxattr(struct dentry *d, const char __user *name, void __user *value,
430 size_t size)
431{
432 ssize_t error;
433 void *kvalue = NULL;
434 void *vvalue = NULL;
435 char kname[XATTR_NAME_MAX + 1];
436
437 error = strncpy_from_user(kname, name, sizeof(kname));
438 if (error == 0 || error == sizeof(kname))
439 error = -ERANGE;
440 if (error < 0)
441 return error;
442
443 if (size) {
444 if (size > XATTR_SIZE_MAX)
445 size = XATTR_SIZE_MAX;
446 kvalue = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
447 if (!kvalue) {
448 vvalue = vmalloc(size);
449 if (!vvalue)
450 return -ENOMEM;
451 kvalue = vvalue;
452 }
453 }
454
455 error = vfs_getxattr(d, kname, kvalue, size);
456 if (error > 0) {
457 if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
458 (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0))
459 posix_acl_fix_xattr_to_user(kvalue, size);
460 if (size && copy_to_user(value, kvalue, error))
461 error = -EFAULT;
462 } else if (error == -ERANGE && size >= XATTR_SIZE_MAX) {
463
464
465 error = -E2BIG;
466 }
467 if (vvalue)
468 vfree(vvalue);
469 else
470 kfree(kvalue);
471 return error;
472}
473
474SYSCALL_DEFINE4(getxattr, const char __user *, pathname,
475 const char __user *, name, void __user *, value, size_t, size)
476{
477 struct path path;
478 ssize_t error;
479
480 error = user_path(pathname, &path);
481 if (error)
482 return error;
483 error = getxattr(path.dentry, name, value, size);
484 path_put(&path);
485 return error;
486}
487
488SYSCALL_DEFINE4(lgetxattr, const char __user *, pathname,
489 const char __user *, name, void __user *, value, size_t, size)
490{
491 struct path path;
492 ssize_t error;
493
494 error = user_lpath(pathname, &path);
495 if (error)
496 return error;
497 error = getxattr(path.dentry, name, value, size);
498 path_put(&path);
499 return error;
500}
501
502SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name,
503 void __user *, value, size_t, size)
504{
505 struct fd f = fdget(fd);
506 ssize_t error = -EBADF;
507
508 if (!f.file)
509 return error;
510 audit_inode(NULL, f.file->f_path.dentry, 0);
511 error = getxattr(f.file->f_path.dentry, name, value, size);
512 fdput(f);
513 return error;
514}
515
516
517
518
519static ssize_t
520listxattr(struct dentry *d, char __user *list, size_t size)
521{
522 ssize_t error;
523 char *klist = NULL;
524 char *vlist = NULL;
525
526 if (size) {
527 if (size > XATTR_LIST_MAX)
528 size = XATTR_LIST_MAX;
529 klist = kmalloc(size, __GFP_NOWARN | GFP_KERNEL);
530 if (!klist) {
531 vlist = vmalloc(size);
532 if (!vlist)
533 return -ENOMEM;
534 klist = vlist;
535 }
536 }
537
538 error = vfs_listxattr(d, klist, size);
539 if (error > 0) {
540 if (size && copy_to_user(list, klist, error))
541 error = -EFAULT;
542 } else if (error == -ERANGE && size >= XATTR_LIST_MAX) {
543
544
545 error = -E2BIG;
546 }
547 if (vlist)
548 vfree(vlist);
549 else
550 kfree(klist);
551 return error;
552}
553
554SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list,
555 size_t, size)
556{
557 struct path path;
558 ssize_t error;
559
560 error = user_path(pathname, &path);
561 if (error)
562 return error;
563 error = listxattr(path.dentry, list, size);
564 path_put(&path);
565 return error;
566}
567
568SYSCALL_DEFINE3(llistxattr, const char __user *, pathname, char __user *, list,
569 size_t, size)
570{
571 struct path path;
572 ssize_t error;
573
574 error = user_lpath(pathname, &path);
575 if (error)
576 return error;
577 error = listxattr(path.dentry, list, size);
578 path_put(&path);
579 return error;
580}
581
582SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size)
583{
584 struct fd f = fdget(fd);
585 ssize_t error = -EBADF;
586
587 if (!f.file)
588 return error;
589 audit_inode(NULL, f.file->f_path.dentry, 0);
590 error = listxattr(f.file->f_path.dentry, list, size);
591 fdput(f);
592 return error;
593}
594
595
596
597
598static long
599removexattr(struct dentry *d, const char __user *name)
600{
601 int error;
602 char kname[XATTR_NAME_MAX + 1];
603
604 error = strncpy_from_user(kname, name, sizeof(kname));
605 if (error == 0 || error == sizeof(kname))
606 error = -ERANGE;
607 if (error < 0)
608 return error;
609
610 return vfs_removexattr(d, kname);
611}
612
613SYSCALL_DEFINE2(removexattr, const char __user *, pathname,
614 const char __user *, name)
615{
616 struct path path;
617 int error;
618
619 error = user_path(pathname, &path);
620 if (error)
621 return error;
622 error = mnt_want_write(path.mnt);
623 if (!error) {
624 error = removexattr(path.dentry, name);
625 mnt_drop_write(path.mnt);
626 }
627 path_put(&path);
628 return error;
629}
630
631SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname,
632 const char __user *, name)
633{
634 struct path path;
635 int error;
636
637 error = user_lpath(pathname, &path);
638 if (error)
639 return error;
640 error = mnt_want_write(path.mnt);
641 if (!error) {
642 error = removexattr(path.dentry, name);
643 mnt_drop_write(path.mnt);
644 }
645 path_put(&path);
646 return error;
647}
648
649SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name)
650{
651 struct fd f = fdget(fd);
652 struct dentry *dentry;
653 int error = -EBADF;
654
655 if (!f.file)
656 return error;
657 dentry = f.file->f_path.dentry;
658 audit_inode(NULL, dentry, 0);
659 error = mnt_want_write_file(f.file);
660 if (!error) {
661 error = removexattr(dentry, name);
662 mnt_drop_write_file(f.file);
663 }
664 fdput(f);
665 return error;
666}
667
668
669static const char *
670strcmp_prefix(const char *a, const char *a_prefix)
671{
672 while (*a_prefix && *a == *a_prefix) {
673 a++;
674 a_prefix++;
675 }
676 return *a_prefix ? NULL : a;
677}
678
679
680
681
682
683
684
685
686
687
688#define for_each_xattr_handler(handlers, handler) \
689 for ((handler) = *(handlers)++; \
690 (handler) != NULL; \
691 (handler) = *(handlers)++)
692
693
694
695
696static const struct xattr_handler *
697xattr_resolve_name(const struct xattr_handler **handlers, const char **name)
698{
699 const struct xattr_handler *handler;
700
701 if (!*name)
702 return NULL;
703
704 for_each_xattr_handler(handlers, handler) {
705 const char *n = strcmp_prefix(*name, handler->prefix);
706 if (n) {
707 *name = n;
708 break;
709 }
710 }
711 return handler;
712}
713
714
715
716
717ssize_t
718generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size)
719{
720 const struct xattr_handler *handler;
721
722 handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
723 if (!handler)
724 return -EOPNOTSUPP;
725 return handler->get(dentry, name, buffer, size, handler->flags);
726}
727
728
729
730
731
732ssize_t
733generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
734{
735 const struct xattr_handler *handler, **handlers = dentry->d_sb->s_xattr;
736 unsigned int size = 0;
737
738 if (!buffer) {
739 for_each_xattr_handler(handlers, handler) {
740 size += handler->list(dentry, NULL, 0, NULL, 0,
741 handler->flags);
742 }
743 } else {
744 char *buf = buffer;
745
746 for_each_xattr_handler(handlers, handler) {
747 size = handler->list(dentry, buf, buffer_size,
748 NULL, 0, handler->flags);
749 if (size > buffer_size)
750 return -ERANGE;
751 buf += size;
752 buffer_size -= size;
753 }
754 size = buf - buffer;
755 }
756 return size;
757}
758
759
760
761
762int
763generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags)
764{
765 const struct xattr_handler *handler;
766
767 if (size == 0)
768 value = "";
769 handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
770 if (!handler)
771 return -EOPNOTSUPP;
772 return handler->set(dentry, name, value, size, flags, handler->flags);
773}
774
775
776
777
778
779int
780generic_removexattr(struct dentry *dentry, const char *name)
781{
782 const struct xattr_handler *handler;
783
784 handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
785 if (!handler)
786 return -EOPNOTSUPP;
787 return handler->set(dentry, name, NULL, 0,
788 XATTR_REPLACE, handler->flags);
789}
790
791EXPORT_SYMBOL(generic_getxattr);
792EXPORT_SYMBOL(generic_listxattr);
793EXPORT_SYMBOL(generic_setxattr);
794EXPORT_SYMBOL(generic_removexattr);
795
796
797
798
799struct simple_xattr *simple_xattr_alloc(const void *value, size_t size)
800{
801 struct simple_xattr *new_xattr;
802 size_t len;
803
804
805 len = sizeof(*new_xattr) + size;
806 if (len <= sizeof(*new_xattr))
807 return NULL;
808
809 new_xattr = kmalloc(len, GFP_KERNEL);
810 if (!new_xattr)
811 return NULL;
812
813 new_xattr->size = size;
814 memcpy(new_xattr->value, value, size);
815 return new_xattr;
816}
817
818
819
820
821int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
822 void *buffer, size_t size)
823{
824 struct simple_xattr *xattr;
825 int ret = -ENODATA;
826
827 spin_lock(&xattrs->lock);
828 list_for_each_entry(xattr, &xattrs->head, list) {
829 if (strcmp(name, xattr->name))
830 continue;
831
832 ret = xattr->size;
833 if (buffer) {
834 if (size < xattr->size)
835 ret = -ERANGE;
836 else
837 memcpy(buffer, xattr->value, xattr->size);
838 }
839 break;
840 }
841 spin_unlock(&xattrs->lock);
842 return ret;
843}
844
845static int __simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
846 const void *value, size_t size, int flags)
847{
848 struct simple_xattr *xattr;
849 struct simple_xattr *new_xattr = NULL;
850 int err = 0;
851
852
853 if (value) {
854 new_xattr = simple_xattr_alloc(value, size);
855 if (!new_xattr)
856 return -ENOMEM;
857
858 new_xattr->name = kstrdup(name, GFP_KERNEL);
859 if (!new_xattr->name) {
860 kfree(new_xattr);
861 return -ENOMEM;
862 }
863 }
864
865 spin_lock(&xattrs->lock);
866 list_for_each_entry(xattr, &xattrs->head, list) {
867 if (!strcmp(name, xattr->name)) {
868 if (flags & XATTR_CREATE) {
869 xattr = new_xattr;
870 err = -EEXIST;
871 } else if (new_xattr) {
872 list_replace(&xattr->list, &new_xattr->list);
873 } else {
874 list_del(&xattr->list);
875 }
876 goto out;
877 }
878 }
879 if (flags & XATTR_REPLACE) {
880 xattr = new_xattr;
881 err = -ENODATA;
882 } else {
883 list_add(&new_xattr->list, &xattrs->head);
884 xattr = NULL;
885 }
886out:
887 spin_unlock(&xattrs->lock);
888 if (xattr) {
889 kfree(xattr->name);
890 kfree(xattr);
891 }
892 return err;
893
894}
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
911 const void *value, size_t size, int flags)
912{
913 if (size == 0)
914 value = "";
915 return __simple_xattr_set(xattrs, name, value, size, flags);
916}
917
918
919
920
921int simple_xattr_remove(struct simple_xattrs *xattrs, const char *name)
922{
923 return __simple_xattr_set(xattrs, name, NULL, 0, XATTR_REPLACE);
924}
925
926static bool xattr_is_trusted(const char *name)
927{
928 return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);
929}
930
931
932
933
934ssize_t simple_xattr_list(struct simple_xattrs *xattrs, char *buffer,
935 size_t size)
936{
937 bool trusted = capable(CAP_SYS_ADMIN);
938 struct simple_xattr *xattr;
939 size_t used = 0;
940
941 spin_lock(&xattrs->lock);
942 list_for_each_entry(xattr, &xattrs->head, list) {
943 size_t len;
944
945
946 if (!trusted && xattr_is_trusted(xattr->name))
947 continue;
948
949 len = strlen(xattr->name) + 1;
950 used += len;
951 if (buffer) {
952 if (size < used) {
953 used = -ERANGE;
954 break;
955 }
956 memcpy(buffer, xattr->name, len);
957 buffer += len;
958 }
959 }
960 spin_unlock(&xattrs->lock);
961
962 return used;
963}
964
965
966
967
968void simple_xattr_list_add(struct simple_xattrs *xattrs,
969 struct simple_xattr *new_xattr)
970{
971 spin_lock(&xattrs->lock);
972 list_add(&new_xattr->list, &xattrs->head);
973 spin_unlock(&xattrs->lock);
974}
975