#include <linux/inotify.h>
#include <linux/namei.h>
#include <linux/mount.h>
+#include <linux/kthread.h>
+#include <linux/slab.h>
struct audit_tree;
struct audit_chunk;
struct list_head trees; /* with root here */
int dead;
int count;
+ atomic_long_t refs;
struct rcu_head head;
struct node {
struct list_head list;
* tree is refcounted; one reference for "some rules on rules_list refer to
* it", one for each chunk with pointer to it.
*
- * chunk is refcounted by embedded inotify_watch.
+ * chunk is refcounted by embedded inotify_watch + .refs (non-zero refcount
+ * of watch contributes 1 to .refs).
*
* node.index allows to get from node.list to containing chunk.
* MSB of that sucker is stolen to mark taggings that we might have to
INIT_LIST_HEAD(&chunk->hash);
INIT_LIST_HEAD(&chunk->trees);
chunk->count = count;
+ atomic_long_set(&chunk->refs, 1);
for (i = 0; i < count; i++) {
INIT_LIST_HEAD(&chunk->owners[i].list);
chunk->owners[i].index = i;
return chunk;
}
-static void __free_chunk(struct rcu_head *rcu)
+static void free_chunk(struct audit_chunk *chunk)
{
- struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head);
int i;
for (i = 0; i < chunk->count; i++) {
kfree(chunk);
}
-static inline void free_chunk(struct audit_chunk *chunk)
+void audit_put_chunk(struct audit_chunk *chunk)
{
- call_rcu(&chunk->head, __free_chunk);
+ if (atomic_long_dec_and_test(&chunk->refs))
+ free_chunk(chunk);
}
-void audit_put_chunk(struct audit_chunk *chunk)
+static void __put_chunk(struct rcu_head *rcu)
{
- put_inotify_watch(&chunk->watch);
+ struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head);
+ audit_put_chunk(chunk);
}
enum {HASH_SIZE = 128};
struct audit_chunk *audit_tree_lookup(const struct inode *inode)
{
struct list_head *list = chunk_hash(inode);
- struct list_head *pos;
+ struct audit_chunk *p;
- list_for_each_rcu(pos, list) {
- struct audit_chunk *p = container_of(pos, struct audit_chunk, hash);
+ list_for_each_entry_rcu(p, list, hash) {
if (p->watch.inode == inode) {
- get_inotify_watch(&p->watch);
+ atomic_long_inc(&p->refs);
return p;
}
}
/* tagging and untagging inodes with trees */
-static void untag_chunk(struct audit_chunk *chunk, struct node *p)
+static struct audit_chunk *find_chunk(struct node *p)
+{
+ int index = p->index & ~(1U<<31);
+ p -= index;
+ return container_of(p, struct audit_chunk, owners[0]);
+}
+
+static void untag_chunk(struct node *p)
{
+ struct audit_chunk *chunk = find_chunk(p);
struct audit_chunk *new;
struct audit_tree *owner;
int size = chunk->count - 1;
int i, j;
+ if (!pin_inotify_watch(&chunk->watch)) {
+ /*
+ * Filesystem is shutting down; all watches are getting
+ * evicted, just take it off the node list for this
+ * tree and let the eviction logics take care of the
+ * rest.
+ */
+ owner = p->owner;
+ if (owner->root == chunk) {
+ list_del_init(&owner->same_root);
+ owner->root = NULL;
+ }
+ list_del_init(&p->list);
+ p->owner = NULL;
+ put_tree(owner);
+ return;
+ }
+
+ spin_unlock(&hash_lock);
+
+ /*
+ * pin_inotify_watch() succeeded, so the watch won't go away
+ * from under us.
+ */
mutex_lock(&chunk->watch.inode->inotify_mutex);
if (chunk->dead) {
mutex_unlock(&chunk->watch.inode->inotify_mutex);
- return;
+ goto out;
}
owner = p->owner;
inotify_evict_watch(&chunk->watch);
mutex_unlock(&chunk->watch.inode->inotify_mutex);
put_inotify_watch(&chunk->watch);
- return;
+ goto out;
}
new = alloc_chunk(size);
owner->root = NULL;
}
- for (i = j = 0; i < size; i++, j++) {
+ for (i = j = 0; j <= size; i++, j++) {
struct audit_tree *s;
if (&chunk->owners[j] == p) {
list_del_init(&p->list);
if (!s) /* result of earlier fallback */
continue;
get_tree(s);
- list_replace_init(&chunk->owners[i].list, &new->owners[j].list);
+ list_replace_init(&chunk->owners[j].list, &new->owners[i].list);
}
list_replace_rcu(&chunk->hash, &new->hash);
inotify_evict_watch(&chunk->watch);
mutex_unlock(&chunk->watch.inode->inotify_mutex);
put_inotify_watch(&chunk->watch);
- return;
+ goto out;
Fallback:
// do the best we can
put_tree(owner);
spin_unlock(&hash_lock);
mutex_unlock(&chunk->watch.inode->inotify_mutex);
+out:
+ unpin_inotify_watch(&chunk->watch);
+ spin_lock(&hash_lock);
}
static int create_chunk(struct inode *inode, struct audit_tree *tree)
for (n = 0; n < old->count; n++) {
if (old->owners[n].owner == tree) {
spin_unlock(&hash_lock);
- put_inotify_watch(watch);
+ put_inotify_watch(&old->watch);
return 0;
}
}
spin_unlock(&hash_lock);
chunk = alloc_chunk(old->count + 1);
- if (!chunk)
+ if (!chunk) {
+ put_inotify_watch(&old->watch);
return -ENOMEM;
+ }
mutex_lock(&inode->inotify_mutex);
if (inotify_clone_watch(&old->watch, &chunk->watch) < 0) {
mutex_unlock(&inode->inotify_mutex);
+ put_inotify_watch(&old->watch);
free_chunk(chunk);
return -ENOSPC;
}
chunk->dead = 1;
inotify_evict_watch(&chunk->watch);
mutex_unlock(&inode->inotify_mutex);
+ put_inotify_watch(&old->watch);
put_inotify_watch(&chunk->watch);
return 0;
}
spin_unlock(&hash_lock);
inotify_evict_watch(&old->watch);
mutex_unlock(&inode->inotify_mutex);
- put_inotify_watch(&old->watch);
+ put_inotify_watch(&old->watch); /* pair to inotify_find_watch */
+ put_inotify_watch(&old->watch); /* and kill it */
return 0;
}
-static struct audit_chunk *find_chunk(struct node *p)
-{
- int index = p->index & ~(1U<<31);
- p -= index;
- return container_of(p, struct audit_chunk, owners[0]);
-}
-
static void kill_rules(struct audit_tree *tree)
{
struct audit_krule *rule, *next;
if (rule->tree) {
/* not a half-baked one */
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
- audit_log_format(ab, "op=remove rule dir=");
+ audit_log_format(ab, "op=");
+ audit_log_string(ab, "remove rule");
+ audit_log_format(ab, " dir=");
audit_log_untrustedstring(ab, rule->tree->pathname);
- if (rule->filterkey) {
- audit_log_format(ab, " key=");
- audit_log_untrustedstring(ab, rule->filterkey);
- } else
- audit_log_format(ab, " key=(null)");
+ audit_log_key(ab, rule->filterkey);
audit_log_format(ab, " list=%d res=1", rule->listnr);
audit_log_end(ab);
rule->tree = NULL;
list_del_rcu(&entry->list);
+ list_del(&entry->rule.list);
call_rcu(&entry->rcu, audit_free_rule_rcu);
}
}
spin_lock(&hash_lock);
while (!list_empty(&victim->chunks)) {
struct node *p;
- struct audit_chunk *chunk;
p = list_entry(victim->chunks.next, struct node, list);
- chunk = find_chunk(p);
- get_inotify_watch(&chunk->watch);
- spin_unlock(&hash_lock);
- untag_chunk(chunk, p);
-
- put_inotify_watch(&chunk->watch);
- spin_lock(&hash_lock);
+ untag_chunk(p);
}
spin_unlock(&hash_lock);
put_tree(victim);
while (!list_empty(&tree->chunks)) {
struct node *node;
- struct audit_chunk *chunk;
node = list_entry(tree->chunks.next, struct node, list);
if (!(node->index & (1U<<31)))
break;
- chunk = find_chunk(node);
- get_inotify_watch(&chunk->watch);
- spin_unlock(&hash_lock);
-
- untag_chunk(chunk, node);
-
- put_inotify_watch(&chunk->watch);
- spin_lock(&hash_lock);
+ untag_chunk(node);
}
if (!tree->root && !tree->goner) {
tree->goner = 1;
}
}
+static void audit_schedule_prune(void);
+
/* called with audit_filter_mutex */
int audit_remove_tree_rule(struct audit_krule *rule)
{
return 0;
}
+static int compare_root(struct vfsmount *mnt, void *arg)
+{
+ return mnt->mnt_root->d_inode == arg;
+}
+
void audit_trim_trees(void)
{
struct list_head cursor;
list_add(&cursor, &tree_list);
while (cursor.next != &tree_list) {
struct audit_tree *tree;
- struct nameidata nd;
+ struct path path;
struct vfsmount *root_mnt;
struct node *node;
- struct list_head list;
int err;
tree = container_of(cursor.next, struct audit_tree, list);
list_add(&cursor, &tree->list);
mutex_unlock(&audit_filter_mutex);
- err = path_lookup(tree->pathname, 0, &nd);
+ err = kern_path(tree->pathname, 0, &path);
if (err)
goto skip_it;
- root_mnt = collect_mounts(nd.path.mnt, nd.path.dentry);
- path_release(&nd);
+ root_mnt = collect_mounts(&path);
+ path_put(&path);
if (!root_mnt)
goto skip_it;
- list_add_tail(&list, &root_mnt->mnt_list);
spin_lock(&hash_lock);
list_for_each_entry(node, &tree->chunks, list) {
- struct audit_chunk *chunk = find_chunk(node);
- struct inode *inode = chunk->watch.inode;
- struct vfsmount *mnt;
+ struct inode *inode = find_chunk(node)->watch.inode;
node->index |= 1U<<31;
- list_for_each_entry(mnt, &list, mnt_list) {
- if (mnt->mnt_root->d_inode == inode) {
- node->index &= ~(1U<<31);
- break;
- }
- }
+ if (iterate_mounts(compare_root, inode, root_mnt))
+ node->index &= ~(1U<<31);
}
spin_unlock(&hash_lock);
trim_marked(tree);
put_tree(tree);
- list_del_init(&list);
drop_collected_mounts(root_mnt);
skip_it:
mutex_lock(&audit_filter_mutex);
mutex_unlock(&audit_filter_mutex);
}
-static int is_under(struct vfsmount *mnt, struct dentry *dentry,
- struct nameidata *nd)
-{
- if (mnt != nd->path.mnt) {
- for (;;) {
- if (mnt->mnt_parent == mnt)
- return 0;
- if (mnt->mnt_parent == nd->path.mnt)
- break;
- mnt = mnt->mnt_parent;
- }
- dentry = mnt->mnt_mountpoint;
- }
- return is_subdir(dentry, nd->path.dentry);
-}
-
int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op)
{
if (pathname[0] != '/' ||
rule->listnr != AUDIT_FILTER_EXIT ||
- op & ~AUDIT_EQUAL ||
+ op != Audit_equal ||
rule->inode_f || rule->watch || rule->tree)
return -EINVAL;
rule->tree = alloc_tree(pathname);
put_tree(tree);
}
+static int tag_mount(struct vfsmount *mnt, void *arg)
+{
+ return tag_chunk(mnt->mnt_root->d_inode, arg);
+}
+
/* called with audit_filter_mutex */
int audit_add_tree_rule(struct audit_krule *rule)
{
struct audit_tree *seed = rule->tree, *tree;
- struct nameidata nd;
- struct vfsmount *mnt, *p;
- struct list_head list;
+ struct path path;
+ struct vfsmount *mnt;
int err;
list_for_each_entry(tree, &tree_list, list) {
/* do not set rule->tree yet */
mutex_unlock(&audit_filter_mutex);
- err = path_lookup(tree->pathname, 0, &nd);
+ err = kern_path(tree->pathname, 0, &path);
if (err)
goto Err;
- mnt = collect_mounts(nd.path.mnt, nd.path.dentry);
- path_release(&nd);
+ mnt = collect_mounts(&path);
+ path_put(&path);
if (!mnt) {
err = -ENOMEM;
goto Err;
}
- list_add_tail(&list, &mnt->mnt_list);
get_tree(tree);
- list_for_each_entry(p, &list, mnt_list) {
- err = tag_chunk(p->mnt_root->d_inode, tree);
- if (err)
- break;
- }
-
- list_del(&list);
+ err = iterate_mounts(tag_mount, tree, mnt);
drop_collected_mounts(mnt);
if (!err) {
{
struct list_head cursor, barrier;
int failed = 0;
- struct nameidata nd;
+ struct path path1, path2;
struct vfsmount *tagged;
- struct list_head list;
- struct vfsmount *mnt;
- struct dentry *dentry;
int err;
- err = path_lookup(new, 0, &nd);
+ err = kern_path(new, 0, &path2);
if (err)
return err;
- tagged = collect_mounts(nd.path.mnt, nd.path.dentry);
- path_release(&nd);
+ tagged = collect_mounts(&path2);
+ path_put(&path2);
if (!tagged)
return -ENOMEM;
- err = path_lookup(old, 0, &nd);
+ err = kern_path(old, 0, &path1);
if (err) {
drop_collected_mounts(tagged);
return err;
}
- mnt = mntget(nd.path.mnt);
- dentry = dget(nd.path.dentry);
- path_release(&nd);
-
- if (dentry == tagged->mnt_root && dentry == mnt->mnt_root)
- follow_up(&mnt, &dentry);
-
- list_add_tail(&list, &tagged->mnt_list);
mutex_lock(&audit_filter_mutex);
list_add(&barrier, &tree_list);
while (cursor.next != &tree_list) {
struct audit_tree *tree;
- struct vfsmount *p;
+ int good_one = 0;
tree = container_of(cursor.next, struct audit_tree, list);
get_tree(tree);
list_add(&cursor, &tree->list);
mutex_unlock(&audit_filter_mutex);
- err = path_lookup(tree->pathname, 0, &nd);
- if (err) {
- put_tree(tree);
- mutex_lock(&audit_filter_mutex);
- continue;
+ err = kern_path(tree->pathname, 0, &path2);
+ if (!err) {
+ good_one = path_is_under(&path1, &path2);
+ path_put(&path2);
}
- spin_lock(&vfsmount_lock);
- if (!is_under(mnt, dentry, &nd)) {
- spin_unlock(&vfsmount_lock);
- path_release(&nd);
+ if (!good_one) {
put_tree(tree);
mutex_lock(&audit_filter_mutex);
continue;
}
- spin_unlock(&vfsmount_lock);
- path_release(&nd);
-
- list_for_each_entry(p, &list, mnt_list) {
- failed = tag_chunk(p->mnt_root->d_inode, tree);
- if (failed)
- break;
- }
+ failed = iterate_mounts(tag_mount, tree, tagged);
if (failed) {
put_tree(tree);
mutex_lock(&audit_filter_mutex);
}
list_del(&barrier);
list_del(&cursor);
- list_del(&list);
mutex_unlock(&audit_filter_mutex);
- dput(dentry);
- mntput(mnt);
+ path_put(&path1);
drop_collected_mounts(tagged);
return failed;
}
/*
* That gets run when evict_chunk() ends up needing to kill audit_tree.
- * Runs from a separate thread, with audit_cmd_mutex held.
+ * Runs from a separate thread.
*/
-void audit_prune_trees(void)
+static int prune_tree_thread(void *unused)
{
+ mutex_lock(&audit_cmd_mutex);
mutex_lock(&audit_filter_mutex);
while (!list_empty(&prune_list)) {
}
mutex_unlock(&audit_filter_mutex);
+ mutex_unlock(&audit_cmd_mutex);
+ return 0;
+}
+
+static void audit_schedule_prune(void)
+{
+ kthread_run(prune_tree_thread, NULL, "audit_prune_tree");
+}
+
+/*
+ * ... and that one is done if evict_chunk() decides to delay until the end
+ * of syscall. Runs synchronously.
+ */
+void audit_kill_trees(struct list_head *list)
+{
+ mutex_lock(&audit_cmd_mutex);
+ mutex_lock(&audit_filter_mutex);
+
+ while (!list_empty(list)) {
+ struct audit_tree *victim;
+
+ victim = list_entry(list->next, struct audit_tree, list);
+ kill_rules(victim);
+ list_del_init(&victim->list);
+
+ mutex_unlock(&audit_filter_mutex);
+
+ prune_one(victim);
+
+ mutex_lock(&audit_filter_mutex);
+ }
+
+ mutex_unlock(&audit_filter_mutex);
+ mutex_unlock(&audit_cmd_mutex);
}
/*
static void evict_chunk(struct audit_chunk *chunk)
{
struct audit_tree *owner;
+ struct list_head *postponed = audit_killed_trees();
+ int need_prune = 0;
int n;
if (chunk->dead)
owner->root = NULL;
list_del_init(&owner->same_root);
spin_unlock(&hash_lock);
- kill_rules(owner);
- list_move(&owner->list, &prune_list);
- audit_schedule_prune();
+ if (!postponed) {
+ kill_rules(owner);
+ list_move(&owner->list, &prune_list);
+ need_prune = 1;
+ } else {
+ list_move(&owner->list, postponed);
+ }
spin_lock(&hash_lock);
}
list_del_rcu(&chunk->hash);
for (n = 0; n < chunk->count; n++)
list_del_init(&chunk->owners[n].list);
spin_unlock(&hash_lock);
+ if (need_prune)
+ audit_schedule_prune();
mutex_unlock(&audit_filter_mutex);
}
static void destroy_watch(struct inotify_watch *watch)
{
struct audit_chunk *chunk = container_of(watch, struct audit_chunk, watch);
- free_chunk(chunk);
+ call_rcu(&chunk->head, __put_chunk);
}
static const struct inotify_operations rtree_inotify_ops = {
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff