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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2010-02-22 20:04:56 -0500
committerIngo Molnar <mingo@elte.hu>2010-02-25 04:34:52 -0500
commite7b0a61b7929632d36cf052d9e2820ef0a9c1bfe (patch)
tree69dbe6f03abc5a9ef0dea3a2c28921cebcc59a08 /security
parent96be753af91fc9d582450a84722f6a6721d218ad (diff)
security: Apply lockdep-based checking to rcu_dereference() uses
Apply lockdep-ified RCU primitives to key_gc_keyring() and keyring_destroy(). Cc: David Howells <dhowells@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1266887105-1528-12-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'security')
-rw-r--r--security/keys/gc.c3
-rw-r--r--security/keys/keyring.c4
2 files changed, 5 insertions, 2 deletions
diff --git a/security/keys/gc.c b/security/keys/gc.c
index 4770be375ff..19902319d09 100644
--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -77,7 +77,8 @@ static bool key_gc_keyring(struct key *keyring, time_t limit)
77 goto dont_gc; 77 goto dont_gc;
78 78
79 /* scan the keyring looking for dead keys */ 79 /* scan the keyring looking for dead keys */
80 klist = rcu_dereference(keyring->payload.subscriptions); 80 klist = rcu_dereference_check(keyring->payload.subscriptions,
81 lockdep_is_held(&key_serial_lock));
81 if (!klist) 82 if (!klist)
82 goto dont_gc; 83 goto dont_gc;
83 84
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 8ec02746ca9..e814d2109f8 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -151,7 +151,9 @@ static void keyring_destroy(struct key *keyring)
151 write_unlock(&keyring_name_lock); 151 write_unlock(&keyring_name_lock);
152 } 152 }
153 153
154 klist = rcu_dereference(keyring->payload.subscriptions); 154 klist = rcu_dereference_check(keyring->payload.subscriptions,
155 rcu_read_lock_held() ||
156 atomic_read(&keyring->usage) == 0);
155 if (klist) { 157 if (klist) {
156 for (loop = klist->nkeys - 1; loop >= 0; loop--) 158 for (loop = klist->nkeys - 1; loop >= 0; loop--)
157 key_put(klist->keys[loop]); 159 key_put(klist->keys[loop]);
generated by cgit v1.2.2 (git 2.25.0) at 2026-07-10 00:25:24 -0400
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/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * 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 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would 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 the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_alloc.h"
#include "xfs_dmapi.h"
#include "xfs_quota.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_bmap.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_rtalloc.h"
#include "xfs_error.h"
#include "xfs_itable.h"
#include "xfs_rw.h"
#include "xfs_acl.h"
#include "xfs_attr.h"
#include "xfs_buf_item.h"
#include "xfs_utils.h"
#include "xfs_vnodeops.h"

#include <linux/capability.h>
#include <linux/xattr.h>
#include <linux/namei.h>
#include <linux/security.h>
#include <linux/falloc.h>

/*
 * Bring the atime in the XFS inode uptodate.
 * Used before logging the inode to disk or when the Linux inode goes away.
 */
void
xfs_synchronize_atime(
	xfs_inode_t	*ip)
{
	struct inode	*inode = ip->i_vnode;

	if (inode) {
		ip->i_d.di_atime.t_sec = (__int32_t)inode->i_atime.tv_sec;
		ip->i_d.di_atime.t_nsec = (__int32_t)inode->i_atime.tv_nsec;
	}
}

/*
 * If the linux inode exists, mark it dirty.
 * Used when commiting a dirty inode into a transaction so that
 * the inode will get written back by the linux code
 */
void
xfs_mark_inode_dirty_sync(
	xfs_inode_t	*ip)
{
	struct inode	*inode = ip->i_vnode;

	if (inode)
		mark_inode_dirty_sync(inode);
}

/*
 * Change the requested timestamp in the given inode.
 * We don't lock across timestamp updates, and we don't log them but
 * we do record the fact that there is dirty information in core.
 *
 * NOTE -- callers MUST combine XFS_ICHGTIME_MOD or XFS_ICHGTIME_CHG
 *		with XFS_ICHGTIME_ACC to be sure that access time
 *		update will take.  Calling first with XFS_ICHGTIME_ACC
 *		and then XFS_ICHGTIME_MOD may fail to modify the access
 *		timestamp if the filesystem is mounted noacctm.
 */
void
xfs_ichgtime(
	xfs_inode_t	*ip,
	int		flags)
{
	struct inode	*inode = vn_to_inode(XFS_ITOV(ip));
	timespec_t	tv;

	nanotime(&tv);
	if (flags & XFS_ICHGTIME_MOD) {
		inode->i_mtime = tv;
		ip->i_d.di_mtime.t_sec = (__int32_t)tv.tv_sec;
		ip->i_d.di_mtime.t_nsec = (__int32_t)tv.tv_nsec;
	}
	if (flags & XFS_ICHGTIME_ACC) {
		inode->i_atime = tv;
		ip->i_d.di_atime.t_sec = (__int32_t)tv.tv_sec;
		ip->i_d.di_atime.t_nsec = (__int32_t)tv.tv_nsec;
	}
	if (flags & XFS_ICHGTIME_CHG) {
		inode->i_ctime = tv;
		ip->i_d.di_ctime.t_sec = (__int32_t)tv.tv_sec;
		ip->i_d.di_ctime.t_nsec = (__int32_t)tv.tv_nsec;
	}

	/*
	 * We update the i_update_core field _after_ changing
	 * the timestamps in order to coordinate properly with
	 * xfs_iflush() so that we don't lose timestamp updates.
	 * This keeps us from having to hold the inode lock
	 * while doing this.  We use the SYNCHRONIZE macro to
	 * ensure that the compiler does not reorder the update
	 * of i_update_core above the timestamp updates above.
	 */
	SYNCHRONIZE();
	ip->i_update_core = 1;
	if (!(inode->i_state & I_NEW))
		mark_inode_dirty_sync(inode);
}

/*
 * Variant on the above which avoids querying the system clock
 * in situations where we know the Linux inode timestamps have
 * just been updated (and so we can update our inode cheaply).
 */
void
xfs_ichgtime_fast(
	xfs_inode_t	*ip,
	struct inode	*inode,
	int		flags)
{
	timespec_t	*tvp;

	/*
	 * Atime updates for read() & friends are handled lazily now, and
	 * explicit updates must go through xfs_ichgtime()
	 */
	ASSERT((flags & XFS_ICHGTIME_ACC) == 0);

	if (flags & XFS_ICHGTIME_MOD) {
		tvp = &inode->i_mtime;
		ip->i_d.di_mtime.t_sec = (__int32_t)tvp->tv_sec;
		ip->i_d.di_mtime.t_nsec = (__int32_t)tvp->tv_nsec;
	}
	if (flags & XFS_ICHGTIME_CHG) {
		tvp = &inode->i_ctime;
		ip->i_d.di_ctime.t_sec = (__int32_t)tvp->tv_sec;
		ip->i_d.di_ctime.t_nsec = (__int32_t)tvp->tv_nsec;
	}

	/*
	 * We update the i_update_core field _after_ changing
	 * the timestamps in order to coordinate properly with
	 * xfs_iflush() so that we don't lose timestamp updates.
	 * This keeps us from having to hold the inode lock
	 * while doing this.  We use the SYNCHRONIZE macro to
	 * ensure that the compiler does not reorder the update
	 * of i_update_core above the timestamp updates above.
	 */
	SYNCHRONIZE();
	ip->i_update_core = 1;
	if (!(inode->i_state & I_NEW))
		mark_inode_dirty_sync(inode);
}


/*
 * Pull the link count and size up from the xfs inode to the linux inode
 */
STATIC void
xfs_validate_fields(
	struct inode		*inode)
{
	struct xfs_inode	*ip = XFS_I(inode);
	loff_t size;

	/* we're under i_sem so i_size can't change under us */
	size = XFS_ISIZE(ip);
	if (i_size_read(inode) != size)
		i_size_write(inode, size);
}

/*
 * Hook in SELinux.  This is not quite correct yet, what we really need
 * here (as we do for default ACLs) is a mechanism by which creation of
 * these attrs can be journalled at inode creation time (along with the
 * inode, of course, such that log replay can't cause these to be lost).
 */
STATIC int
xfs_init_security(
	struct inode	*inode,
	struct inode	*dir)
{
	struct xfs_inode *ip = XFS_I(inode);
	size_t		length;
	void		*value;
	char		*name;
	int		error;

	error = security_inode_init_security(inode, dir, &name,
					     &value, &length);
	if (error) {
		if (error == -EOPNOTSUPP)
			return 0;
		return -error;
	}

	error = xfs_attr_set(ip, name, value, length, ATTR_SECURE);
	if (!error)
		xfs_iflags_set(ip, XFS_IMODIFIED);

	kfree(name);
	kfree(value);
	return error;
}

static void
xfs_dentry_to_name(
	struct xfs_name	*namep,
	struct dentry	*dentry)
{
	namep->name = dentry->d_name.name;
	namep->len = dentry->d_name.len;
}

STATIC void
xfs_cleanup_inode(
	struct inode	*dir,
	struct inode	*inode,
	struct dentry	*dentry,
	int		mode)
{
	struct xfs_name	teardown;

	/* Oh, the horror.
	 * If we can't add the ACL or we fail in
	 * xfs_init_security we must back out.
	 * ENOSPC can hit here, among other things.
	 */
	xfs_dentry_to_name(&teardown, dent