aboutsummaryrefslogtreecommitdiffstats
path: root/arch/m32r/include
diff options
context:
space:
mode:
authorDavid Howells <dhowells@redhat.com>2010-04-27 17:05:11 -0400
committerJames Morris <jmorris@namei.org>2010-04-27 18:37:15 -0400
commitb59ec78cdcc57e02bc3dddfa7134a2f0fd15c34d (patch)
tree60ba3c907d4d83873bce5eb645ae8bd9415399b8 /arch/m32r/include
parentb91ce4d14a21fc04d165be30319541e0f9204f15 (diff)
keys: don't need to use RCU in keyring_read() as semaphore is held
keyring_read() doesn't need to use rcu_dereference() to access the keyring payload as the caller holds the key semaphore to prevent modifications from happening whilst the data is read out. This should solve the following warning: =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- security/keys/keyring.c:204 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 1 lock held by keyctl/2144: #0: (&key->sem){+++++.}, at: [<ffffffff81177f7c>] keyctl_read_key+0x9c/0xcf stack backtrace: Pid: 2144, comm: keyctl Not tainted 2.6.34-rc2-cachefs #113 Call Trace: [<ffffffff8105121f>] lockdep_rcu_dereference+0xaa/0xb2 [<ffffffff811762d5>] keyring_read+0x4d/0xe7 [<ffffffff81177f8c>] keyctl_read_key+0xac/0xcf [<ffffffff811788d4>] sys_keyctl+0x75/0xb9 [<ffffffff81001eeb>] system_call_fastpath+0x16/0x1b Signed-off-by: David Howells <dhowells@redhat.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'arch/m32r/include')
0 files changed, 0 insertions, 0 deletions
generated by cgit v1.2.2 (git 2.25.0) at 2025-10-27 16:53:02 -0400
313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 
/*
 * Copyright (C) 2007 Red Hat.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/fs.h>
#include <linux/string.h>
#include <linux/xattr.h>
#include <linux/posix_acl_xattr.h>
#include <linux/posix_acl.h>
#include <linux/sched.h>

#include "ctree.h"
#include "btrfs_inode.h"
#include "xattr.h"

#ifdef CONFIG_FS_POSIX_ACL

static void btrfs_update_cached_acl(struct inode *inode,
				    struct posix_acl **p_acl,
				    struct posix_acl *acl)
{
	spin_lock(&inode->i_lock);
	if (*p_acl && *p_acl != BTRFS_ACL_NOT_CACHED)
		posix_acl_release(*p_acl);
	*p_acl = posix_acl_dup(acl);
	spin_unlock(&inode->i_lock);
}

static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
{
	int size;
	const char *name;
	char *value = NULL;
	struct posix_acl *acl = NULL, **p_acl;

	switch (type) {
	case ACL_TYPE_ACCESS:
		name = POSIX_ACL_XATTR_ACCESS;
		p_acl = &BTRFS_I(inode)->i_acl;
		break;
	case ACL_TYPE_DEFAULT:
		name = POSIX_ACL_XATTR_DEFAULT;
		p_acl = &BTRFS_I(inode)->i_default_acl;
		break;
	default:
		return ERR_PTR(-EINVAL);
	}

	spin_lock(&inode->i_lock);
	if (*p_acl != BTRFS_ACL_NOT_CACHED)
		acl = posix_acl_dup(*p_acl);
	spin_unlock(&inode->i_lock);

	if (acl)
		return acl;


	size = __btrfs_getxattr(inode, name, "", 0);
	if (size > 0) {
		value = kzalloc(size, GFP_NOFS);
		if (!value)
			return ERR_PTR(-ENOMEM);
		size = __btrfs_getxattr(inode, name, value, size);
		if (size > 0) {
			acl = posix_acl_from_xattr(value, size);
			btrfs_update_cached_acl(inode, p_acl, acl);
		}
		kfree(value);
	} else if (size == -ENOENT) {
		acl = NULL;
		btrfs_update_cached_acl(inode, p_acl, acl);
	}

	return acl;
}

static int btrfs_xattr_get_acl(struct inode *inode, int type,
			       void *value, size_t size)
{
	struct posix_acl *acl;
	int ret = 0;

	acl = btrfs_get_acl(inode, type);

	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl == NULL)
		return -ENODATA;
	ret = posix_acl_to_xattr(acl, value, size);
	posix_acl_release(acl);

	return ret;
}

/*
 * Needs to be called with fs_mutex held
 */
static int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{
	int ret, size = 0;
	const char *name;
	struct posix_acl **p_acl;
	char *value = NULL;
	mode_t mode;

	if (acl) {
		ret = posix_acl_valid(acl);
		if (ret < 0)
			return ret;
		ret = 0;
	}

	switch (type) {
	case ACL_TYPE_ACCESS:
		mode = inode->i_mode;
		ret = posix_acl_equiv_mode(acl, &mode);
		if (ret < 0)
			return ret;
		ret = 0;
		inode->i_mode = mode;
		name = POSIX_ACL_XATTR_ACCESS;
		p_acl = &BTRFS_I(inode)->i_acl;
		break;
	case ACL_TYPE_DEFAULT:
		if (!S_ISDIR(inode->i_mode))
			return acl ? -EINVAL : 0;
		name = POSIX_ACL_XATTR_DEFAULT;
		p_acl = &BTRFS_I(inode)->i_default_acl;
		break;
	default:
		return -EINVAL;
	}

	if (acl) {
		size = posix_acl_xattr_size(acl->a_count);
		value = kmalloc(size, GFP_NOFS);
		if (!value) {
			ret = -ENOMEM;
			goto out;
		}

		ret = posix_acl_to_xattr(acl, value, size);
		if (ret < 0)
			goto out;
	}

	ret = __btrfs_setxattr(inode, name, value, size, 0);

out:
	kfree(value);

	if (!ret)
		btrfs_update_cached_acl(inode, p_acl, acl);

	return ret;
}

static int btrfs_xattr_set_acl(struct inode *inode, int type,
			       const void *value, size_t size)
{
	int ret = 0;
	struct posix_acl *acl = NULL;

	if (value) {
		acl = posix_acl_from_xattr(value, size);
		if (acl == NULL) {
			value = NULL;
			size = 0;
		} else if (IS_ERR(acl)) {
			return PTR_ERR(acl);
		}
	}

	ret = btrfs_set_acl(inode, acl, type);

	posix_acl_release(acl);

	return ret;
}


static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name,
				      void *value, size_t size)
{
	return btrfs_xattr_get_acl(inode, ACL_TYPE_ACCESS, value, size);
}

static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name,
				      const void *value, size_t size, int flags)
{
	return btrfs_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
}

static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name,
				       void *value, size_t size)
{
	return btrfs_xattr_get_acl(inode, ACL_TYPE_DEFAULT, value, size);
}

static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name,
			       const void *value, size_t size, int flags)
{
	return btrfs_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
}

int btrfs_check_acl(struct inode *inode, int mask)
{
	struct posix_acl *acl;
	int error = -EAGAIN;

	acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);

	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl) {
		error = posix_acl_permission(inode, acl, mask);
		posix_acl_release(acl);
	}

	return error;
}

/*
 * btrfs_init_acl is already generally called under fs_mutex, so the locking
 * stuff has been fixed to work with that.  If the locking stuff changes, we
 * need to re-evaluate the acl locking stuff.
 */
int btrfs_init_acl(struct inode *inode, struct inode *dir)
{
	struct posix_acl *acl = NULL;
	int ret = 0;

	/* this happens with subvols */
	if (!dir)
		return 0;

	if (!S_ISLNK(inode->i_mode)) {
		if (IS_POSIXACL(dir)) {
			acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT);
			if (IS_ERR(acl))
				return PTR_ERR(acl);
		}

		if (!acl)
			inode->i_mode &= ~current->fs->umask;
	}

	if (IS_POSIXACL(dir) && acl) {
		struct posix_acl *clone;
		mode_t mode;

		if (S_ISDIR(inode->i_mode)) {
			ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT);
			if (ret)
				goto failed;
		}
		clone = posix_acl_clone(acl, GFP_NOFS);
		ret = -ENOMEM;
		if (!clone)
			goto failed;

		mode = inode->i_mode;
		ret = posix_acl_create_masq(clone, &mode);
		if (ret >= 0) {
			inode->i_mode = mode;
			if (ret > 0) {
				/* we need an acl */
				ret = btrfs_set_acl(inode, clone,
						    ACL_TYPE_ACCESS);
			}
		}
	}
failed:
	posix_acl_release(acl);

	return ret;
}

int btrfs_acl_chmod(struct inode *inode)
{
	struct posix_acl *acl, *clone;
	int ret = 0;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;

	if (!IS_POSIXACL(inode))
		return 0;

	acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl) || !acl)
		return PTR_ERR(acl);

	clone = posix_acl_clone(acl, GFP_KERNEL);
	posix_acl_release(acl);
	if (!clone)
		return -ENOMEM;

	ret = posix_acl_chmod_masq(clone, inode->i_mode);
	if (!ret)
		ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS);

	posix_acl_release(clone);

	return ret;
}

struct xattr_handler btrfs_xattr_acl_default_handler = {
	.prefix = POSIX_ACL_XATTR_DEFAULT,
	.get	= btrfs_xattr_acl_default_get,
	.set	= btrfs_xattr_acl_default_set,
};

struct xattr_handler btrfs_xattr_acl_access_handler = {
	.prefix = POSIX_ACL_XATTR_ACCESS,
	.get	= btrfs_xattr_acl_access_get,
	.set	= btrfs_xattr_acl_access_set,
};

#else /* CONFIG_FS_POSIX_ACL */

int btrfs_acl_chmod(struct inode *inode)
{
	return 0;
}

int btrfs_init_acl(struct inode *inode, struct inode *dir)
{
	return 0;
}

int btrfs_check_acl(struct inode *inode, int mask)
{
	return 0;
}

#endif /* CONFIG_FS_POSIX_ACL */
generated by cgit v1.2.2 (git 2.25.0) at 2025-10-27 16:53:02 -0400