blob: 2c7776403abaf9ad5a98c318ab7f33267e94329e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 File: fs/xattr.c
3
4 Extended attribute handling.
5
6 Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org>
7 Copyright (C) 2001 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com>
8 Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
9 */
10#include <linux/fs.h>
11#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/file.h>
13#include <linux/xattr.h>
Dave Hansen18f335a2008-02-15 14:37:38 -080014#include <linux/mount.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/namei.h>
16#include <linux/security.h>
Mimi Zoharc7b87de2011-03-09 14:39:18 -050017#include <linux/evm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/syscalls.h>
Paul Gortmaker630d9c42011-11-16 23:57:37 -050019#include <linux/export.h>
Robert Love0eeca282005-07-12 17:06:03 -040020#include <linux/fsnotify.h>
Amy Griffis73241cc2005-11-03 16:00:25 +000021#include <linux/audit.h>
Andrew Morton0d08d7b2012-04-05 14:25:07 -070022#include <linux/vmalloc.h>
Eric W. Biederman2f6f0652012-02-07 18:52:57 -080023#include <linux/posix_acl_xattr.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
Andrew Morton0d08d7b2012-04-05 14:25:07 -070025#include <asm/uaccess.h>
Christoph Hellwig5be196e2006-01-09 20:51:55 -080026
akpm@osdl.orge0ad7b02006-01-09 20:51:56 -080027/*
28 * Check permissions for extended attribute access. This is a bit complicated
29 * because different namespaces have very different rules.
30 */
31static int
32xattr_permission(struct inode *inode, const char *name, int mask)
33{
34 /*
35 * We can never set or remove an extended attribute on a read-only
36 * filesystem or on an immutable / append-only inode.
37 */
38 if (mask & MAY_WRITE) {
akpm@osdl.orge0ad7b02006-01-09 20:51:56 -080039 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
40 return -EPERM;
41 }
42
43 /*
44 * No restriction for security.* and system.* from the VFS. Decision
45 * on these is left to the underlying filesystem / security module.
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 /*
Andreas Gruenbacher55b23bd2011-05-27 14:50:36 +020052 * The trusted.* namespace can only be accessed by privileged users.
akpm@osdl.orge0ad7b02006-01-09 20:51:56 -080053 */
Andreas Gruenbacher55b23bd2011-05-27 14:50:36 +020054 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 }
akpm@osdl.orge0ad7b02006-01-09 20:51:56 -080059
Andreas Gruenbacher55b23bd2011-05-27 14:50:36 +020060 /*
61 * In the user.* namespace, only regular files and directories can have
Andreas Gruenbacherf1f2d872006-11-02 22:07:29 -080062 * extended attributes. For sticky directories, only the owner and
Andreas Gruenbacher55b23bd2011-05-27 14:50:36 +020063 * privileged users can write attributes.
Andreas Gruenbacherf1f2d872006-11-02 22:07:29 -080064 */
akpm@osdl.orge0ad7b02006-01-09 20:51:56 -080065 if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) {
Andreas Gruenbacherf1f2d872006-11-02 22:07:29 -080066 if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
Andreas Gruenbacher55b23bd2011-05-27 14:50:36 +020067 return (mask & MAY_WRITE) ? -EPERM : -ENODATA;
Andreas Gruenbacherf1f2d872006-11-02 22:07:29 -080068 if (S_ISDIR(inode->i_mode) && (inode->i_mode & S_ISVTX) &&
Serge E. Hallyn2e149672011-03-23 16:43:26 -070069 (mask & MAY_WRITE) && !inode_owner_or_capable(inode))
akpm@osdl.orge0ad7b02006-01-09 20:51:56 -080070 return -EPERM;
71 }
72
Al Virof419a2e2008-07-22 00:07:17 -040073 return inode_permission(inode, mask);
akpm@osdl.orge0ad7b02006-01-09 20:51:56 -080074}
75
David P. Quigleyb1ab7e42009-09-03 14:25:56 -040076/**
77 * __vfs_setxattr_noperm - perform setxattr operation without performing
78 * permission checks.
79 *
80 * @dentry - object to perform setxattr on
81 * @name - xattr name to set
82 * @value - value to set @name to
83 * @size - size of @value
84 * @flags - flags to pass into filesystem operations
85 *
86 * returns the result of the internal setxattr or setsecurity operations.
87 *
88 * This function requires the caller to lock the inode's i_mutex before it
89 * is executed. It also assumes that the caller will make the appropriate
90 * permission checks.
91 */
92int __vfs_setxattr_noperm(struct dentry *dentry, const char *name,
93 const void *value, size_t size, int flags)
Christoph Hellwig5be196e2006-01-09 20:51:55 -080094{
95 struct inode *inode = dentry->d_inode;
David P. Quigleyb1ab7e42009-09-03 14:25:56 -040096 int error = -EOPNOTSUPP;
Andi Kleen69b45732011-05-28 08:25:51 -070097 int issec = !strncmp(name, XATTR_SECURITY_PREFIX,
98 XATTR_SECURITY_PREFIX_LEN);
Christoph Hellwig5be196e2006-01-09 20:51:55 -080099
Andi Kleen69b45732011-05-28 08:25:51 -0700100 if (issec)
101 inode->i_flags &= ~S_NOSEC;
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800102 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 }
Andi Kleen69b45732011-05-28 08:25:51 -0700109 } else if (issec) {
akpm@osdl.orge0ad7b02006-01-09 20:51:56 -0800110 const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800111 error = security_inode_setsecurity(inode, suffix, value,
112 size, flags);
113 if (!error)
114 fsnotify_xattr(dentry);
115 }
David P. Quigleyb1ab7e42009-09-03 14:25:56 -0400116
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
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800139out:
140 mutex_unlock(&inode->i_mutex);
141 return error;
142}
143EXPORT_SYMBOL_GPL(vfs_setxattr);
144
145ssize_t
David P. Quigley42492592008-02-04 22:29:39 -0800146xattr_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
Mimi Zohar1601fba2011-03-09 14:23:34 -0500172/*
173 * vfs_getxattr_alloc - allocate memory, if necessary, before calling getxattr
174 *
175 * Allocate memory, if not already allocated, or re-allocate correct size,
176 * before retrieving the extended attribute.
177 *
178 * Returns the result of alloc, if failed, or the getxattr operation.
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
David P. Quigley42492592008-02-04 22:29:39 -0800211ssize_t
David Howells8f0cfa52008-04-29 00:59:41 -0700212vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size)
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800213{
214 struct inode *inode = dentry->d_inode;
215 int error;
216
akpm@osdl.orge0ad7b02006-01-09 20:51:56 -0800217 error = xattr_permission(inode, name, MAY_READ);
218 if (error)
219 return error;
220
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800221 error = security_inode_getxattr(dentry, name);
222 if (error)
223 return error;
224
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800225 if (!strncmp(name, XATTR_SECURITY_PREFIX,
akpm@osdl.orge0ad7b02006-01-09 20:51:56 -0800226 XATTR_SECURITY_PREFIX_LEN)) {
227 const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
David P. Quigley42492592008-02-04 22:29:39 -0800228 int ret = xattr_getsecurity(inode, suffix, value, size);
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800229 /*
230 * Only overwrite the return value if a security module
231 * is actually active.
232 */
David P. Quigley4bea5802008-02-04 22:29:40 -0800233 if (ret == -EOPNOTSUPP)
234 goto nolsm;
235 return ret;
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800236 }
David P. Quigley4bea5802008-02-04 22:29:40 -0800237nolsm:
238 if (inode->i_op->getxattr)
239 error = inode->i_op->getxattr(dentry, name, value, size);
240 else
241 error = -EOPNOTSUPP;
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800242
243 return error;
244}
245EXPORT_SYMBOL_GPL(vfs_getxattr);
246
Bill Nottingham659564c2006-10-09 16:10:48 -0400247ssize_t
248vfs_listxattr(struct dentry *d, char *list, size_t size)
249{
250 ssize_t error;
251
252 error = security_inode_listxattr(d);
253 if (error)
254 return error;
255 error = -EOPNOTSUPP;
Al Viroacfa4382008-12-04 10:06:33 -0500256 if (d->d_inode->i_op->listxattr) {
Bill Nottingham659564c2006-10-09 16:10:48 -0400257 error = d->d_inode->i_op->listxattr(d, list, size);
258 } else {
259 error = security_inode_listsecurity(d->d_inode, list, size);
260 if (size && error > size)
261 error = -ERANGE;
262 }
263 return error;
264}
265EXPORT_SYMBOL_GPL(vfs_listxattr);
266
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800267int
David Howells8f0cfa52008-04-29 00:59:41 -0700268vfs_removexattr(struct dentry *dentry, const char *name)
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800269{
270 struct inode *inode = dentry->d_inode;
271 int error;
272
273 if (!inode->i_op->removexattr)
274 return -EOPNOTSUPP;
275
akpm@osdl.orge0ad7b02006-01-09 20:51:56 -0800276 error = xattr_permission(inode, name, MAY_WRITE);
277 if (error)
278 return error;
279
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800280 mutex_lock(&inode->i_mutex);
Mimi Zohar2ab51f32011-03-23 17:23:06 -0400281 error = security_inode_removexattr(dentry, name);
Dmitry Kasatkin7c51bb02014-11-20 16:31:01 +0200282 if (error)
283 goto out;
Mimi Zohar2ab51f32011-03-23 17:23:06 -0400284
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800285 error = inode->i_op->removexattr(dentry, name);
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800286
Mimi Zoharc7b87de2011-03-09 14:39:18 -0500287 if (!error) {
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800288 fsnotify_xattr(dentry);
Mimi Zoharc7b87de2011-03-09 14:39:18 -0500289 evm_inode_post_removexattr(dentry, name);
290 }
Dmitry Kasatkin7c51bb02014-11-20 16:31:01 +0200291
292out:
293 mutex_unlock(&inode->i_mutex);
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800294 return error;
295}
296EXPORT_SYMBOL_GPL(vfs_removexattr);
297
298
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299/*
300 * Extended attribute SET operations
301 */
302static long
David Howells8f0cfa52008-04-29 00:59:41 -0700303setxattr(struct dentry *d, const char __user *name, const void __user *value,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 size_t size, int flags)
305{
306 int error;
307 void *kvalue = NULL;
Andrew Morton44c82492012-04-05 14:25:07 -0700308 void *vvalue = NULL; /* If non-NULL, we used vmalloc() */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 char kname[XATTR_NAME_MAX + 1];
310
311 if (flags & ~(XATTR_CREATE|XATTR_REPLACE))
312 return -EINVAL;
313
314 error = strncpy_from_user(kname, name, sizeof(kname));
315 if (error == 0 || error == sizeof(kname))
316 error = -ERANGE;
317 if (error < 0)
318 return error;
319
320 if (size) {
321 if (size > XATTR_SIZE_MAX)
322 return -E2BIG;
Andrew Morton44c82492012-04-05 14:25:07 -0700323 kvalue = kmalloc(size, GFP_KERNEL | __GFP_NOWARN);
324 if (!kvalue) {
325 vvalue = vmalloc(size);
326 if (!vvalue)
327 return -ENOMEM;
328 kvalue = vvalue;
329 }
330 if (copy_from_user(kvalue, value, size)) {
331 error = -EFAULT;
332 goto out;
333 }
Eric W. Biederman2f6f0652012-02-07 18:52:57 -0800334 if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
335 (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0))
336 posix_acl_fix_xattr_from_user(kvalue, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 }
338
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800339 error = vfs_setxattr(d, kname, kvalue, size, flags);
Andrew Morton44c82492012-04-05 14:25:07 -0700340out:
341 if (vvalue)
342 vfree(vvalue);
343 else
344 kfree(kvalue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 return error;
346}
347
Eric Biggers8cc43112014-10-12 11:59:58 -0500348static int path_setxattr(const char __user *pathname,
349 const char __user *name, const void __user *value,
350 size_t size, int flags, unsigned int lookup_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351{
Al Viro2d8f3032008-07-22 09:59:21 -0400352 struct path path;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 int error;
Jeff Layton68f1bb82012-12-11 12:10:15 -0500354retry:
355 error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 if (error)
357 return error;
Al Viro2d8f3032008-07-22 09:59:21 -0400358 error = mnt_want_write(path.mnt);
Dave Hansen18f335a2008-02-15 14:37:38 -0800359 if (!error) {
Al Viro2d8f3032008-07-22 09:59:21 -0400360 error = setxattr(path.dentry, name, value, size, flags);
361 mnt_drop_write(path.mnt);
Dave Hansen18f335a2008-02-15 14:37:38 -0800362 }
Al Viro2d8f3032008-07-22 09:59:21 -0400363 path_put(&path);
Jeff Layton68f1bb82012-12-11 12:10:15 -0500364 if (retry_estale(error, lookup_flags)) {
365 lookup_flags |= LOOKUP_REVAL;
366 goto retry;
367 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 return error;
369}
370
Eric Biggers8cc43112014-10-12 11:59:58 -0500371SYSCALL_DEFINE5(setxattr, const char __user *, pathname,
372 const char __user *, name, const void __user *, value,
373 size_t, size, int, flags)
374{
375 return path_setxattr(pathname, name, value, size, flags, LOOKUP_FOLLOW);
376}
377
Heiko Carstens64fd1de2009-01-14 14:14:14 +0100378SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname,
379 const char __user *, name, const void __user *, value,
380 size_t, size, int, flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381{
Eric Biggers8cc43112014-10-12 11:59:58 -0500382 return path_setxattr(pathname, name, value, size, flags, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383}
384
Heiko Carstens64fd1de2009-01-14 14:14:14 +0100385SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name,
386 const void __user *,value, size_t, size, int, flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387{
Al Viro2903ff02012-08-28 12:52:22 -0400388 struct fd f = fdget(fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 int error = -EBADF;
390
Al Viro2903ff02012-08-28 12:52:22 -0400391 if (!f.file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 return error;
Al Viro9f45f5b2014-10-31 17:44:57 -0400393 audit_file(f.file);
Al Viro2903ff02012-08-28 12:52:22 -0400394 error = mnt_want_write_file(f.file);
Dave Hansen18f335a2008-02-15 14:37:38 -0800395 if (!error) {
Al Viro9f45f5b2014-10-31 17:44:57 -0400396 error = setxattr(f.file->f_path.dentry, name, value, size, flags);
Al Viro2903ff02012-08-28 12:52:22 -0400397 mnt_drop_write_file(f.file);
Dave Hansen18f335a2008-02-15 14:37:38 -0800398 }
Al Viro2903ff02012-08-28 12:52:22 -0400399 fdput(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 return error;
401}
402
403/*
404 * Extended attribute GET operations
405 */
406static ssize_t
David Howells8f0cfa52008-04-29 00:59:41 -0700407getxattr(struct dentry *d, const char __user *name, void __user *value,
408 size_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409{
410 ssize_t error;
411 void *kvalue = NULL;
Sasha Levin779302e2012-07-30 14:39:13 -0700412 void *vvalue = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 char kname[XATTR_NAME_MAX + 1];
414
415 error = strncpy_from_user(kname, name, sizeof(kname));
416 if (error == 0 || error == sizeof(kname))
417 error = -ERANGE;
418 if (error < 0)
419 return error;
420
421 if (size) {
422 if (size > XATTR_SIZE_MAX)
423 size = XATTR_SIZE_MAX;
Sasha Levin779302e2012-07-30 14:39:13 -0700424 kvalue = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
425 if (!kvalue) {
426 vvalue = vmalloc(size);
427 if (!vvalue)
428 return -ENOMEM;
429 kvalue = vvalue;
430 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 }
432
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800433 error = vfs_getxattr(d, kname, kvalue, size);
Stephen Smalleyf549d6c2005-09-03 15:55:18 -0700434 if (error > 0) {
Eric W. Biederman2f6f0652012-02-07 18:52:57 -0800435 if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
436 (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0))
437 posix_acl_fix_xattr_to_user(kvalue, size);
Stephen Smalleyf549d6c2005-09-03 15:55:18 -0700438 if (size && copy_to_user(value, kvalue, error))
439 error = -EFAULT;
440 } else if (error == -ERANGE && size >= XATTR_SIZE_MAX) {
441 /* The file system tried to returned a value bigger
442 than XATTR_SIZE_MAX bytes. Not possible. */
443 error = -E2BIG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 }
Sasha Levin779302e2012-07-30 14:39:13 -0700445 if (vvalue)
446 vfree(vvalue);
447 else
448 kfree(kvalue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 return error;
450}
451
Eric Biggers8cc43112014-10-12 11:59:58 -0500452static ssize_t path_getxattr(const char __user *pathname,
453 const char __user *name, void __user *value,
454 size_t size, unsigned int lookup_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455{
Al Viro2d8f3032008-07-22 09:59:21 -0400456 struct path path;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 ssize_t error;
Jeff Layton60e66b42012-12-11 12:10:16 -0500458retry:
459 error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460 if (error)
461 return error;
Al Viro2d8f3032008-07-22 09:59:21 -0400462 error = getxattr(path.dentry, name, value, size);
463 path_put(&path);
Jeff Layton60e66b42012-12-11 12:10:16 -0500464 if (retry_estale(error, lookup_flags)) {
465 lookup_flags |= LOOKUP_REVAL;
466 goto retry;
467 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 return error;
469}
470
Eric Biggers8cc43112014-10-12 11:59:58 -0500471SYSCALL_DEFINE4(getxattr, const char __user *, pathname,
472 const char __user *, name, void __user *, value, size_t, size)
473{
474 return path_getxattr(pathname, name, value, size, LOOKUP_FOLLOW);
475}
476
Heiko Carstens64fd1de2009-01-14 14:14:14 +0100477SYSCALL_DEFINE4(lgetxattr, const char __user *, pathname,
478 const char __user *, name, void __user *, value, size_t, size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479{
Eric Biggers8cc43112014-10-12 11:59:58 -0500480 return path_getxattr(pathname, name, value, size, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481}
482
Heiko Carstens64fd1de2009-01-14 14:14:14 +0100483SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name,
484 void __user *, value, size_t, size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485{
Al Viro2903ff02012-08-28 12:52:22 -0400486 struct fd f = fdget(fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 ssize_t error = -EBADF;
488
Al Viro2903ff02012-08-28 12:52:22 -0400489 if (!f.file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 return error;
Al Viro9f45f5b2014-10-31 17:44:57 -0400491 audit_file(f.file);
Al Viro2903ff02012-08-28 12:52:22 -0400492 error = getxattr(f.file->f_path.dentry, name, value, size);
493 fdput(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 return error;
495}
496
497/*
498 * Extended attribute LIST operations
499 */
500static ssize_t
501listxattr(struct dentry *d, char __user *list, size_t size)
502{
503 ssize_t error;
504 char *klist = NULL;
Andrew Morton0d08d7b2012-04-05 14:25:07 -0700505 char *vlist = NULL; /* If non-NULL, we used vmalloc() */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506
507 if (size) {
508 if (size > XATTR_LIST_MAX)
509 size = XATTR_LIST_MAX;
Dave Jones703bf2d2012-04-05 14:25:06 -0700510 klist = kmalloc(size, __GFP_NOWARN | GFP_KERNEL);
Andrew Morton0d08d7b2012-04-05 14:25:07 -0700511 if (!klist) {
512 vlist = vmalloc(size);
513 if (!vlist)
514 return -ENOMEM;
515 klist = vlist;
516 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 }
518
Bill Nottingham659564c2006-10-09 16:10:48 -0400519 error = vfs_listxattr(d, klist, size);
Stephen Smalleyf549d6c2005-09-03 15:55:18 -0700520 if (error > 0) {
521 if (size && copy_to_user(list, klist, error))
522 error = -EFAULT;
523 } else if (error == -ERANGE && size >= XATTR_LIST_MAX) {
524 /* The file system tried to returned a list bigger
525 than XATTR_LIST_MAX bytes. Not possible. */
526 error = -E2BIG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 }
Andrew Morton0d08d7b2012-04-05 14:25:07 -0700528 if (vlist)
529 vfree(vlist);
530 else
531 kfree(klist);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 return error;
533}
534
Eric Biggers8cc43112014-10-12 11:59:58 -0500535static ssize_t path_listxattr(const char __user *pathname, char __user *list,
536 size_t size, unsigned int lookup_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537{
Al Viro2d8f3032008-07-22 09:59:21 -0400538 struct path path;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 ssize_t error;
Jeff Layton10a90cf2012-12-11 12:10:16 -0500540retry:
541 error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 if (error)
543 return error;
Al Viro2d8f3032008-07-22 09:59:21 -0400544 error = listxattr(path.dentry, list, size);
545 path_put(&path);
Jeff Layton10a90cf2012-12-11 12:10:16 -0500546 if (retry_estale(error, lookup_flags)) {
547 lookup_flags |= LOOKUP_REVAL;
548 goto retry;
549 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 return error;
551}
552
Eric Biggers8cc43112014-10-12 11:59:58 -0500553SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list,
554 size_t, size)
555{
556 return path_listxattr(pathname, list, size, LOOKUP_FOLLOW);
557}
558
Heiko Carstens64fd1de2009-01-14 14:14:14 +0100559SYSCALL_DEFINE3(llistxattr, const char __user *, pathname, char __user *, list,
560 size_t, size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561{
Eric Biggers8cc43112014-10-12 11:59:58 -0500562 return path_listxattr(pathname, list, size, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563}
564
Heiko Carstens64fd1de2009-01-14 14:14:14 +0100565SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566{
Al Viro2903ff02012-08-28 12:52:22 -0400567 struct fd f = fdget(fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 ssize_t error = -EBADF;
569
Al Viro2903ff02012-08-28 12:52:22 -0400570 if (!f.file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 return error;
Al Viro9f45f5b2014-10-31 17:44:57 -0400572 audit_file(f.file);
Al Viro2903ff02012-08-28 12:52:22 -0400573 error = listxattr(f.file->f_path.dentry, list, size);
574 fdput(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 return error;
576}
577
578/*
579 * Extended attribute REMOVE operations
580 */
581static long
David Howells8f0cfa52008-04-29 00:59:41 -0700582removexattr(struct dentry *d, const char __user *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583{
584 int error;
585 char kname[XATTR_NAME_MAX + 1];
586
587 error = strncpy_from_user(kname, name, sizeof(kname));
588 if (error == 0 || error == sizeof(kname))
589 error = -ERANGE;
590 if (error < 0)
591 return error;
592
Christoph Hellwig5be196e2006-01-09 20:51:55 -0800593 return vfs_removexattr(d, kname);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594}
595
Eric Biggers8cc43112014-10-12 11:59:58 -0500596static int path_removexattr(const char __user *pathname,
597 const char __user *name, unsigned int lookup_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598{
Al Viro2d8f3032008-07-22 09:59:21 -0400599 struct path path;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 int error;
Jeff Layton12f06212012-12-11 12:10:17 -0500601retry:
602 error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 if (error)
604 return error;
Al Viro2d8f3032008-07-22 09:59:21 -0400605 error = mnt_want_write(path.mnt);
Dave Hansen18f335a2008-02-15 14:37:38 -0800606 if (!error) {
Al Viro2d8f3032008-07-22 09:59:21 -0400607 error = removexattr(path.dentry, name);
608 mnt_drop_write(path.mnt);
Dave Hansen18f335a2008-02-15 14:37:38 -0800609 }
Al Viro2d8f3032008-07-22 09:59:21 -0400610 path_put(&path);
Jeff Layton12f06212012-12-11 12:10:17 -0500611 if (retry_estale(error, lookup_flags)) {
612 lookup_flags |= LOOKUP_REVAL;
613 goto retry;
614 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 return error;
616}
617
Eric Biggers8cc43112014-10-12 11:59:58 -0500618SYSCALL_DEFINE2(removexattr, const char __user *, pathname,
619 const char __user *, name)
620{
621 return path_removexattr(pathname, name, LOOKUP_FOLLOW);
622}
623
Heiko Carstens6a6160a2009-01-14 14:14:15 +0100624SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname,
625 const char __user *, name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626{
Eric Biggers8cc43112014-10-12 11:59:58 -0500627 return path_removexattr(pathname, name, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628}
629
Heiko Carstens6a6160a2009-01-14 14:14:15 +0100630SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631{
Al Viro2903ff02012-08-28 12:52:22 -0400632 struct fd f = fdget(fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 int error = -EBADF;
634
Al Viro2903ff02012-08-28 12:52:22 -0400635 if (!f.file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 return error;
Al Viro9f45f5b2014-10-31 17:44:57 -0400637 audit_file(f.file);
Al Viro2903ff02012-08-28 12:52:22 -0400638 error = mnt_want_write_file(f.file);
Dave Hansen18f335a2008-02-15 14:37:38 -0800639 if (!error) {
Al Viro9f45f5b2014-10-31 17:44:57 -0400640 error = removexattr(f.file->f_path.dentry, name);
Al Viro2903ff02012-08-28 12:52:22 -0400641 mnt_drop_write_file(f.file);
Dave Hansen18f335a2008-02-15 14:37:38 -0800642 }
Al Viro2903ff02012-08-28 12:52:22 -0400643 fdput(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 return error;
645}
646
647
648static const char *
649strcmp_prefix(const char *a, const char *a_prefix)
650{
651 while (*a_prefix && *a == *a_prefix) {
652 a++;
653 a_prefix++;
654 }
655 return *a_prefix ? NULL : a;
656}
657
658/*
659 * In order to implement different sets of xattr operations for each xattr
660 * prefix with the generic xattr API, a filesystem should create a
661 * null-terminated array of struct xattr_handler (one for each prefix) and
662 * hang a pointer to it off of the s_xattr field of the superblock.
663 *
664 * The generic_fooxattr() functions will use this list to dispatch xattr
665 * operations to the correct xattr_handler.
666 */
667#define for_each_xattr_handler(handlers, handler) \
668 for ((handler) = *(handlers)++; \
669 (handler) != NULL; \
670 (handler) = *(handlers)++)
671
672/*
673 * Find the xattr_handler with the matching prefix.
674 */
Stephen Hemmingerbb435452010-05-13 17:53:14 -0700675static const struct xattr_handler *
676xattr_resolve_name(const struct xattr_handler **handlers, const char **name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677{
Stephen Hemmingerbb435452010-05-13 17:53:14 -0700678 const struct xattr_handler *handler;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679
680 if (!*name)
681 return NULL;
682
683 for_each_xattr_handler(handlers, handler) {
Andreas Gruenbacher98e9cb52015-12-02 14:44:36 +0100684 const char *n;
685
686 n = strcmp_prefix(*name, xattr_prefix(handler));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 if (n) {
Andreas Gruenbacher98e9cb52015-12-02 14:44:36 +0100688 if (!handler->prefix ^ !*n) {
689 if (*n)
690 continue;
691 return ERR_PTR(-EINVAL);
692 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 *name = n;
Andreas Gruenbacher98e9cb52015-12-02 14:44:36 +0100694 return handler;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 }
696 }
Andreas Gruenbacher98e9cb52015-12-02 14:44:36 +0100697 return ERR_PTR(-EOPNOTSUPP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698}
699
700/*
701 * Find the handler for the prefix and dispatch its get() operation.
702 */
703ssize_t
704generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size)
705{
Stephen Hemmingerbb435452010-05-13 17:53:14 -0700706 const struct xattr_handler *handler;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707
Christoph Hellwig431547b2009-11-13 09:52:56 +0000708 handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
Andreas Gruenbacher98e9cb52015-12-02 14:44:36 +0100709 if (IS_ERR(handler))
710 return PTR_ERR(handler);
Andreas Gruenbacherd9a82a02015-10-04 19:18:51 +0200711 return handler->get(handler, dentry, name, buffer, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712}
713
714/*
715 * Combine the results of the list() operation from every xattr_handler in the
716 * list.
717 */
718ssize_t
719generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
720{
Stephen Hemmingerbb435452010-05-13 17:53:14 -0700721 const struct xattr_handler *handler, **handlers = dentry->d_sb->s_xattr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 unsigned int size = 0;
723
724 if (!buffer) {
Christoph Hellwig431547b2009-11-13 09:52:56 +0000725 for_each_xattr_handler(handlers, handler) {
Andreas Gruenbacherc4803c42015-12-02 14:44:41 +0100726 if (!handler->list)
727 continue;
Andreas Gruenbacherd9a82a02015-10-04 19:18:51 +0200728 size += handler->list(handler, dentry, NULL, 0,
729 NULL, 0);
Christoph Hellwig431547b2009-11-13 09:52:56 +0000730 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 } else {
732 char *buf = buffer;
733
734 for_each_xattr_handler(handlers, handler) {
Andreas Gruenbacherc4803c42015-12-02 14:44:41 +0100735 if (!handler->list)
736 continue;
Andreas Gruenbacherd9a82a02015-10-04 19:18:51 +0200737 size = handler->list(handler, dentry, buf, buffer_size,
738 NULL, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 if (size > buffer_size)
740 return -ERANGE;
741 buf += size;
742 buffer_size -= size;
743 }
744 size = buf - buffer;
745 }
746 return size;
747}
748
749/*
750 * Find the handler for the prefix and dispatch its set() operation.
751 */
752int
753generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags)
754{
Stephen Hemmingerbb435452010-05-13 17:53:14 -0700755 const struct xattr_handler *handler;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756
757 if (size == 0)
758 value = ""; /* empty EA, do not remove */
Christoph Hellwig431547b2009-11-13 09:52:56 +0000759 handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
Andreas Gruenbacher98e9cb52015-12-02 14:44:36 +0100760 if (IS_ERR(handler))
761 return PTR_ERR(handler);
Andreas Gruenbacherd9a82a02015-10-04 19:18:51 +0200762 return handler->set(handler, dentry, name, value, size, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763}
764
765/*
766 * Find the handler for the prefix and dispatch its set() operation to remove
767 * any associated extended attribute.
768 */
769int
770generic_removexattr(struct dentry *dentry, const char *name)
771{
Stephen Hemmingerbb435452010-05-13 17:53:14 -0700772 const struct xattr_handler *handler;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773
Christoph Hellwig431547b2009-11-13 09:52:56 +0000774 handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
Andreas Gruenbacher98e9cb52015-12-02 14:44:36 +0100775 if (IS_ERR(handler))
776 return PTR_ERR(handler);
Andreas Gruenbacherd9a82a02015-10-04 19:18:51 +0200777 return handler->set(handler, dentry, name, NULL, 0, XATTR_REPLACE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778}
779
780EXPORT_SYMBOL(generic_getxattr);
781EXPORT_SYMBOL(generic_listxattr);
782EXPORT_SYMBOL(generic_setxattr);
783EXPORT_SYMBOL(generic_removexattr);
Aristeu Rozanski38f38652012-08-23 16:53:28 -0400784
Andreas Gruenbachere409de92015-10-04 19:18:52 +0200785/**
786 * xattr_full_name - Compute full attribute name from suffix
787 *
788 * @handler: handler of the xattr_handler operation
789 * @name: name passed to the xattr_handler operation
790 *
791 * The get and set xattr handler operations are called with the remainder of
792 * the attribute name after skipping the handler's prefix: for example, "foo"
793 * is passed to the get operation of a handler with prefix "user." to get
794 * attribute "user.foo". The full name is still "there" in the name though.
795 *
796 * Note: the list xattr handler operation when called from the vfs is passed a
797 * NULL name; some file systems use this operation internally, with varying
798 * semantics.
799 */
800const char *xattr_full_name(const struct xattr_handler *handler,
801 const char *name)
802{
Andreas Gruenbacher98e9cb52015-12-02 14:44:36 +0100803 size_t prefix_len = strlen(xattr_prefix(handler));
Andreas Gruenbachere409de92015-10-04 19:18:52 +0200804
805 return name - prefix_len;
806}
807EXPORT_SYMBOL(xattr_full_name);
808
Aristeu Rozanski38f38652012-08-23 16:53:28 -0400809/*
810 * Allocate new xattr and copy in the value; but leave the name to callers.
811 */
812struct simple_xattr *simple_xattr_alloc(const void *value, size_t size)
813{
814 struct simple_xattr *new_xattr;
815 size_t len;
816
817 /* wrap around? */
818 len = sizeof(*new_xattr) + size;
Hugh Dickins4e66d442014-07-23 14:00:17 -0700819 if (len < sizeof(*new_xattr))
Aristeu Rozanski38f38652012-08-23 16:53:28 -0400820 return NULL;
821
822 new_xattr = kmalloc(len, GFP_KERNEL);
823 if (!new_xattr)
824 return NULL;
825
826 new_xattr->size = size;
827 memcpy(new_xattr->value, value, size);
828 return new_xattr;
829}
830
831/*
832 * xattr GET operation for in-memory/pseudo filesystems
833 */
834int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
835 void *buffer, size_t size)
836{
837 struct simple_xattr *xattr;
838 int ret = -ENODATA;
839
840 spin_lock(&xattrs->lock);
841 list_for_each_entry(xattr, &xattrs->head, list) {
842 if (strcmp(name, xattr->name))
843 continue;
844
845 ret = xattr->size;
846 if (buffer) {
847 if (size < xattr->size)
848 ret = -ERANGE;
849 else
850 memcpy(buffer, xattr->value, xattr->size);
851 }
852 break;
853 }
854 spin_unlock(&xattrs->lock);
855 return ret;
856}
857
Andreas Gruenbacheraa7c5242015-12-02 14:44:38 +0100858/**
859 * simple_xattr_set - xattr SET operation for in-memory/pseudo filesystems
860 * @xattrs: target simple_xattr list
861 * @name: name of the extended attribute
862 * @value: value of the xattr. If %NULL, will remove the attribute.
863 * @size: size of the new xattr
864 * @flags: %XATTR_{CREATE|REPLACE}
865 *
866 * %XATTR_CREATE is set, the xattr shouldn't exist already; otherwise fails
867 * with -EEXIST. If %XATTR_REPLACE is set, the xattr should exist;
868 * otherwise, fails with -ENODATA.
869 *
870 * Returns 0 on success, -errno on failure.
871 */
872int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
873 const void *value, size_t size, int flags)
Aristeu Rozanski38f38652012-08-23 16:53:28 -0400874{
875 struct simple_xattr *xattr;
David Rientjes43385842012-10-17 20:41:15 -0700876 struct simple_xattr *new_xattr = NULL;
Aristeu Rozanski38f38652012-08-23 16:53:28 -0400877 int err = 0;
878
879 /* value == NULL means remove */
880 if (value) {
881 new_xattr = simple_xattr_alloc(value, size);
882 if (!new_xattr)
883 return -ENOMEM;
884
885 new_xattr->name = kstrdup(name, GFP_KERNEL);
886 if (!new_xattr->name) {
887 kfree(new_xattr);
888 return -ENOMEM;
889 }
890 }
891
892 spin_lock(&xattrs->lock);
893 list_for_each_entry(xattr, &xattrs->head, list) {
894 if (!strcmp(name, xattr->name)) {
895 if (flags & XATTR_CREATE) {
896 xattr = new_xattr;
897 err = -EEXIST;
898 } else if (new_xattr) {
899 list_replace(&xattr->list, &new_xattr->list);
900 } else {
901 list_del(&xattr->list);
902 }
903 goto out;
904 }
905 }
906 if (flags & XATTR_REPLACE) {
907 xattr = new_xattr;
908 err = -ENODATA;
909 } else {
910 list_add(&new_xattr->list, &xattrs->head);
911 xattr = NULL;
912 }
913out:
914 spin_unlock(&xattrs->lock);
915 if (xattr) {
916 kfree(xattr->name);
917 kfree(xattr);
918 }
919 return err;
920
921}
922
Aristeu Rozanski38f38652012-08-23 16:53:28 -0400923static bool xattr_is_trusted(const char *name)
924{
925 return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);
926}
927
Andreas Gruenbacher786534b2015-12-02 14:44:39 +0100928static int xattr_list_one(char **buffer, ssize_t *remaining_size,
929 const char *name)
930{
931 size_t len = strlen(name) + 1;
932 if (*buffer) {
933 if (*remaining_size < len)
934 return -ERANGE;
935 memcpy(*buffer, name, len);
936 *buffer += len;
937 }
938 *remaining_size -= len;
939 return 0;
940}
941
Aristeu Rozanski38f38652012-08-23 16:53:28 -0400942/*
943 * xattr LIST operation for in-memory/pseudo filesystems
944 */
Andreas Gruenbacher786534b2015-12-02 14:44:39 +0100945ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs,
946 char *buffer, size_t size)
Aristeu Rozanski38f38652012-08-23 16:53:28 -0400947{
948 bool trusted = capable(CAP_SYS_ADMIN);
949 struct simple_xattr *xattr;
Andreas Gruenbacher786534b2015-12-02 14:44:39 +0100950 ssize_t remaining_size = size;
951 int err;
952
953#ifdef CONFIG_FS_POSIX_ACL
954 if (inode->i_acl) {
955 err = xattr_list_one(&buffer, &remaining_size,
956 XATTR_NAME_POSIX_ACL_ACCESS);
957 if (err)
958 return err;
959 }
960 if (inode->i_default_acl) {
961 err = xattr_list_one(&buffer, &remaining_size,
962 XATTR_NAME_POSIX_ACL_DEFAULT);
963 if (err)
964 return err;
965 }
966#endif
Aristeu Rozanski38f38652012-08-23 16:53:28 -0400967
968 spin_lock(&xattrs->lock);
969 list_for_each_entry(xattr, &xattrs->head, list) {
Aristeu Rozanski38f38652012-08-23 16:53:28 -0400970 /* skip "trusted." attributes for unprivileged callers */
971 if (!trusted && xattr_is_trusted(xattr->name))
972 continue;
973
Andreas Gruenbacher786534b2015-12-02 14:44:39 +0100974 err = xattr_list_one(&buffer, &remaining_size, xattr->name);
975 if (err)
976 return err;
Aristeu Rozanski38f38652012-08-23 16:53:28 -0400977 }
978 spin_unlock(&xattrs->lock);
979
Andreas Gruenbacher786534b2015-12-02 14:44:39 +0100980 return size - remaining_size;
Aristeu Rozanski38f38652012-08-23 16:53:28 -0400981}
982
Aristeu Rozanski48957682012-09-11 16:28:11 -0400983/*
984 * Adds an extended attribute to the list
985 */
Aristeu Rozanski38f38652012-08-23 16:53:28 -0400986void simple_xattr_list_add(struct simple_xattrs *xattrs,
987 struct simple_xattr *new_xattr)
988{
989 spin_lock(&xattrs->lock);
990 list_add(&new_xattr->list, &xattrs->head);
991 spin_unlock(&xattrs->lock);
992}