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- #include "audit.h"
- #include <linux/fsnotify_backend.h>
- #include <linux/namei.h>
- #include <linux/mount.h>
- #include <linux/kthread.h>
- #include <linux/slab.h>
- struct audit_tree;
- struct audit_chunk;
- struct audit_tree {
- atomic_t count;
- int goner;
- struct audit_chunk *root;
- struct list_head chunks;
- struct list_head rules;
- struct list_head list;
- struct list_head same_root;
- struct rcu_head head;
- char pathname[];
- };
- struct audit_chunk {
- struct list_head hash;
- struct fsnotify_mark mark;
- 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;
- struct audit_tree *owner;
- unsigned index; /* index; upper bit indicates 'will prune' */
- } owners[];
- };
- static LIST_HEAD(tree_list);
- static LIST_HEAD(prune_list);
- static struct task_struct *prune_thread;
- /*
- * One struct chunk is attached to each inode of interest.
- * We replace struct chunk on tagging/untagging.
- * Rules have pointer to struct audit_tree.
- * Rules have struct list_head rlist forming a list of rules over
- * the same tree.
- * References to struct chunk are collected at audit_inode{,_child}()
- * time and used in AUDIT_TREE rule matching.
- * These references are dropped at the same time we are calling
- * audit_free_names(), etc.
- *
- * Cyclic lists galore:
- * tree.chunks anchors chunk.owners[].list hash_lock
- * tree.rules anchors rule.rlist audit_filter_mutex
- * chunk.trees anchors tree.same_root hash_lock
- * chunk.hash is a hash with middle bits of watch.inode as
- * a hash function. RCU, hash_lock
- *
- * 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 fsnotify_mark + .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
- * revert - several operations have very unpleasant cleanup logics and
- * that makes a difference. Some.
- */
- static struct fsnotify_group *audit_tree_group;
- static struct audit_tree *alloc_tree(const char *s)
- {
- struct audit_tree *tree;
- tree = kmalloc(sizeof(struct audit_tree) + strlen(s) + 1, GFP_KERNEL);
- if (tree) {
- atomic_set(&tree->count, 1);
- tree->goner = 0;
- INIT_LIST_HEAD(&tree->chunks);
- INIT_LIST_HEAD(&tree->rules);
- INIT_LIST_HEAD(&tree->list);
- INIT_LIST_HEAD(&tree->same_root);
- tree->root = NULL;
- strcpy(tree->pathname, s);
- }
- return tree;
- }
- static inline void get_tree(struct audit_tree *tree)
- {
- atomic_inc(&tree->count);
- }
- static inline void put_tree(struct audit_tree *tree)
- {
- if (atomic_dec_and_test(&tree->count))
- kfree_rcu(tree, head);
- }
- /* to avoid bringing the entire thing in audit.h */
- const char *audit_tree_path(struct audit_tree *tree)
- {
- return tree->pathname;
- }
- static void free_chunk(struct audit_chunk *chunk)
- {
- int i;
- for (i = 0; i < chunk->count; i++) {
- if (chunk->owners[i].owner)
- put_tree(chunk->owners[i].owner);
- }
- kfree(chunk);
- }
- void audit_put_chunk(struct audit_chunk *chunk)
- {
- if (atomic_long_dec_and_test(&chunk->refs))
- free_chunk(chunk);
- }
- static void __put_chunk(struct rcu_head *rcu)
- {
- struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head);
- audit_put_chunk(chunk);
- }
- static void audit_tree_destroy_watch(struct fsnotify_mark *entry)
- {
- struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark);
- call_rcu(&chunk->head, __put_chunk);
- }
- static struct audit_chunk *alloc_chunk(int count)
- {
- struct audit_chunk *chunk;
- size_t size;
- int i;
- size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node);
- chunk = kzalloc(size, GFP_KERNEL);
- if (!chunk)
- return NULL;
- 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;
- }
- fsnotify_init_mark(&chunk->mark, audit_tree_destroy_watch);
- chunk->mark.mask = FS_IN_IGNORED;
- return chunk;
- }
- enum {HASH_SIZE = 128};
- static struct list_head chunk_hash_heads[HASH_SIZE];
- static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock);
- static inline struct list_head *chunk_hash(const struct inode *inode)
- {
- unsigned long n = (unsigned long)inode / L1_CACHE_BYTES;
- return chunk_hash_heads + n % HASH_SIZE;
- }
- /* hash_lock & entry->lock is held by caller */
- static void insert_hash(struct audit_chunk *chunk)
- {
- struct fsnotify_mark *entry = &chunk->mark;
- struct list_head *list;
- if (!entry->inode)
- return;
- list = chunk_hash(entry->inode);
- list_add_rcu(&chunk->hash, list);
- }
- /* called under rcu_read_lock */
- struct audit_chunk *audit_tree_lookup(const struct inode *inode)
- {
- struct list_head *list = chunk_hash(inode);
- struct audit_chunk *p;
- list_for_each_entry_rcu(p, list, hash) {
- /* mark.inode may have gone NULL, but who cares? */
- if (p->mark.inode == inode) {
- atomic_long_inc(&p->refs);
- return p;
- }
- }
- return NULL;
- }
- bool audit_tree_match(struct audit_chunk *chunk, struct audit_tree *tree)
- {
- int n;
- for (n = 0; n < chunk->count; n++)
- if (chunk->owners[n].owner == tree)
- return true;
- return false;
- }
- /* tagging and untagging inodes with trees */
- 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 fsnotify_mark *entry = &chunk->mark;
- struct audit_chunk *new = NULL;
- struct audit_tree *owner;
- int size = chunk->count - 1;
- int i, j;
- fsnotify_get_mark(entry);
- spin_unlock(&hash_lock);
- if (size)
- new = alloc_chunk(size);
- spin_lock(&entry->lock);
- if (chunk->dead || !entry->inode) {
- spin_unlock(&entry->lock);
- if (new)
- free_chunk(new);
- goto out;
- }
- owner = p->owner;
- if (!size) {
- chunk->dead = 1;
- spin_lock(&hash_lock);
- list_del_init(&chunk->trees);
- if (owner->root == chunk)
- owner->root = NULL;
- list_del_init(&p->list);
- list_del_rcu(&chunk->hash);
- spin_unlock(&hash_lock);
- spin_unlock(&entry->lock);
- fsnotify_destroy_mark(entry, audit_tree_group);
- goto out;
- }
- if (!new)
- goto Fallback;
- fsnotify_duplicate_mark(&new->mark, entry);
- if (fsnotify_add_mark(&new->mark, new->mark.group, new->mark.inode, NULL, 1)) {
- fsnotify_put_mark(&new->mark);
- goto Fallback;
- }
- chunk->dead = 1;
- spin_lock(&hash_lock);
- list_replace_init(&chunk->trees, &new->trees);
- if (owner->root == chunk) {
- list_del_init(&owner->same_root);
- owner->root = NULL;
- }
- for (i = j = 0; j <= size; i++, j++) {
- struct audit_tree *s;
- if (&chunk->owners[j] == p) {
- list_del_init(&p->list);
- i--;
- continue;
- }
- s = chunk->owners[j].owner;
- new->owners[i].owner = s;
- new->owners[i].index = chunk->owners[j].index - j + i;
- if (!s) /* result of earlier fallback */
- continue;
- get_tree(s);
- list_replace_init(&chunk->owners[j].list, &new->owners[i].list);
- }
- list_replace_rcu(&chunk->hash, &new->hash);
- list_for_each_entry(owner, &new->trees, same_root)
- owner->root = new;
- spin_unlock(&hash_lock);
- spin_unlock(&entry->lock);
- fsnotify_destroy_mark(entry, audit_tree_group);
- fsnotify_put_mark(&new->mark); /* drop initial reference */
- goto out;
- Fallback:
- // do the best we can
- spin_lock(&hash_lock);
- if (owner->root == chunk) {
- list_del_init(&owner->same_root);
- owner->root = NULL;
- }
- list_del_init(&p->list);
- p->owner = NULL;
- put_tree(owner);
- spin_unlock(&hash_lock);
- spin_unlock(&entry->lock);
- out:
- fsnotify_put_mark(entry);
- spin_lock(&hash_lock);
- }
- static int create_chunk(struct inode *inode, struct audit_tree *tree)
- {
- struct fsnotify_mark *entry;
- struct audit_chunk *chunk = alloc_chunk(1);
- if (!chunk)
- return -ENOMEM;
- entry = &chunk->mark;
- if (fsnotify_add_mark(entry, audit_tree_group, inode, NULL, 0)) {
- fsnotify_put_mark(entry);
- return -ENOSPC;
- }
- spin_lock(&entry->lock);
- spin_lock(&hash_lock);
- if (tree->goner) {
- spin_unlock(&hash_lock);
- chunk->dead = 1;
- spin_unlock(&entry->lock);
- fsnotify_destroy_mark(entry, audit_tree_group);
- fsnotify_put_mark(entry);
- return 0;
- }
- chunk->owners[0].index = (1U << 31);
- chunk->owners[0].owner = tree;
- get_tree(tree);
- list_add(&chunk->owners[0].list, &tree->chunks);
- if (!tree->root) {
- tree->root = chunk;
- list_add(&tree->same_root, &chunk->trees);
- }
- insert_hash(chunk);
- spin_unlock(&hash_lock);
- spin_unlock(&entry->lock);
- fsnotify_put_mark(entry); /* drop initial reference */
- return 0;
- }
- /* the first tagged inode becomes root of tree */
- static int tag_chunk(struct inode *inode, struct audit_tree *tree)
- {
- struct fsnotify_mark *old_entry, *chunk_entry;
- struct audit_tree *owner;
- struct audit_chunk *chunk, *old;
- struct node *p;
- int n;
- old_entry = fsnotify_find_inode_mark(audit_tree_group, inode);
- if (!old_entry)
- return create_chunk(inode, tree);
- old = container_of(old_entry, struct audit_chunk, mark);
- /* are we already there? */
- spin_lock(&hash_lock);
- for (n = 0; n < old->count; n++) {
- if (old->owners[n].owner == tree) {
- spin_unlock(&hash_lock);
- fsnotify_put_mark(old_entry);
- return 0;
- }
- }
- spin_unlock(&hash_lock);
- chunk = alloc_chunk(old->count + 1);
- if (!chunk) {
- fsnotify_put_mark(old_entry);
- return -ENOMEM;
- }
- chunk_entry = &chunk->mark;
- spin_lock(&old_entry->lock);
- if (!old_entry->inode) {
- /* old_entry is being shot, lets just lie */
- spin_unlock(&old_entry->lock);
- fsnotify_put_mark(old_entry);
- free_chunk(chunk);
- return -ENOENT;
- }
- fsnotify_duplicate_mark(chunk_entry, old_entry);
- if (fsnotify_add_mark(chunk_entry, chunk_entry->group, chunk_entry->inode, NULL, 1)) {
- spin_unlock(&old_entry->lock);
- fsnotify_put_mark(chunk_entry);
- fsnotify_put_mark(old_entry);
- return -ENOSPC;
- }
- /* even though we hold old_entry->lock, this is safe since chunk_entry->lock could NEVER have been grabbed before */
- spin_lock(&chunk_entry->lock);
- spin_lock(&hash_lock);
- /* we now hold old_entry->lock, chunk_entry->lock, and hash_lock */
- if (tree->goner) {
- spin_unlock(&hash_lock);
- chunk->dead = 1;
- spin_unlock(&chunk_entry->lock);
- spin_unlock(&old_entry->lock);
- fsnotify_destroy_mark(chunk_entry, audit_tree_group);
- fsnotify_put_mark(chunk_entry);
- fsnotify_put_mark(old_entry);
- return 0;
- }
- list_replace_init(&old->trees, &chunk->trees);
- for (n = 0, p = chunk->owners; n < old->count; n++, p++) {
- struct audit_tree *s = old->owners[n].owner;
- p->owner = s;
- p->index = old->owners[n].index;
- if (!s) /* result of fallback in untag */
- continue;
- get_tree(s);
- list_replace_init(&old->owners[n].list, &p->list);
- }
- p->index = (chunk->count - 1) | (1U<<31);
- p->owner = tree;
- get_tree(tree);
- list_add(&p->list, &tree->chunks);
- list_replace_rcu(&old->hash, &chunk->hash);
- list_for_each_entry(owner, &chunk->trees, same_root)
- owner->root = chunk;
- old->dead = 1;
- if (!tree->root) {
- tree->root = chunk;
- list_add(&tree->same_root, &chunk->trees);
- }
- spin_unlock(&hash_lock);
- spin_unlock(&chunk_entry->lock);
- spin_unlock(&old_entry->lock);
- fsnotify_destroy_mark(old_entry, audit_tree_group);
- fsnotify_put_mark(chunk_entry); /* drop initial reference */
- fsnotify_put_mark(old_entry); /* pair to fsnotify_find mark_entry */
- return 0;
- }
- static void audit_tree_log_remove_rule(struct audit_krule *rule)
- {
- struct audit_buffer *ab;
- ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
- if (unlikely(!ab))
- return;
- audit_log_format(ab, "op=");
- audit_log_string(ab, "remove_rule");
- audit_log_format(ab, " dir=");
- audit_log_untrustedstring(ab, rule->tree->pathname);
- audit_log_key(ab, rule->filterkey);
- audit_log_format(ab, " list=%d res=1", rule->listnr);
- audit_log_end(ab);
- }
- static void kill_rules(struct audit_tree *tree)
- {
- struct audit_krule *rule, *next;
- struct audit_entry *entry;
- list_for_each_entry_safe(rule, next, &tree->rules, rlist) {
- entry = container_of(rule, struct audit_entry, rule);
- list_del_init(&rule->rlist);
- if (rule->tree) {
- /* not a half-baked one */
- audit_tree_log_remove_rule(rule);
- if (entry->rule.exe)
- audit_remove_mark(entry->rule.exe);
- rule->tree = NULL;
- list_del_rcu(&entry->list);
- list_del(&entry->rule.list);
- call_rcu(&entry->rcu, audit_free_rule_rcu);
- }
- }
- }
- /*
- * finish killing struct audit_tree
- */
- static void prune_one(struct audit_tree *victim)
- {
- spin_lock(&hash_lock);
- while (!list_empty(&victim->chunks)) {
- struct node *p;
- p = list_entry(victim->chunks.next, struct node, list);
- untag_chunk(p);
- }
- spin_unlock(&hash_lock);
- put_tree(victim);
- }
- /* trim the uncommitted chunks from tree */
- static void trim_marked(struct audit_tree *tree)
- {
- struct list_head *p, *q;
- spin_lock(&hash_lock);
- if (tree->goner) {
- spin_unlock(&hash_lock);
- return;
- }
- /* reorder */
- for (p = tree->chunks.next; p != &tree->chunks; p = q) {
- struct node *node = list_entry(p, struct node, list);
- q = p->next;
- if (node->index & (1U<<31)) {
- list_del_init(p);
- list_add(p, &tree->chunks);
- }
- }
- while (!list_empty(&tree->chunks)) {
- struct node *node;
- node = list_entry(tree->chunks.next, struct node, list);
- /* have we run out of marked? */
- if (!(node->index & (1U<<31)))
- break;
- untag_chunk(node);
- }
- if (!tree->root && !tree->goner) {
- tree->goner = 1;
- spin_unlock(&hash_lock);
- mutex_lock(&audit_filter_mutex);
- kill_rules(tree);
- list_del_init(&tree->list);
- mutex_unlock(&audit_filter_mutex);
- prune_one(tree);
- } else {
- spin_unlock(&hash_lock);
- }
- }
- static void audit_schedule_prune(void);
- /* called with audit_filter_mutex */
- int audit_remove_tree_rule(struct audit_krule *rule)
- {
- struct audit_tree *tree;
- tree = rule->tree;
- if (tree) {
- spin_lock(&hash_lock);
- list_del_init(&rule->rlist);
- if (list_empty(&tree->rules) && !tree->goner) {
- tree->root = NULL;
- list_del_init(&tree->same_root);
- tree->goner = 1;
- list_move(&tree->list, &prune_list);
- rule->tree = NULL;
- spin_unlock(&hash_lock);
- audit_schedule_prune();
- return 1;
- }
- rule->tree = NULL;
- spin_unlock(&hash_lock);
- return 1;
- }
- return 0;
- }
- static int compare_root(struct vfsmount *mnt, void *arg)
- {
- return d_backing_inode(mnt->mnt_root) == arg;
- }
- void audit_trim_trees(void)
- {
- struct list_head cursor;
- mutex_lock(&audit_filter_mutex);
- list_add(&cursor, &tree_list);
- while (cursor.next != &tree_list) {
- struct audit_tree *tree;
- struct path path;
- struct vfsmount *root_mnt;
- struct node *node;
- int err;
- tree = container_of(cursor.next, struct audit_tree, list);
- get_tree(tree);
- list_del(&cursor);
- list_add(&cursor, &tree->list);
- mutex_unlock(&audit_filter_mutex);
- err = kern_path(tree->pathname, 0, &path);
- if (err)
- goto skip_it;
- root_mnt = collect_mounts(&path);
- path_put(&path);
- if (IS_ERR(root_mnt))
- goto skip_it;
- spin_lock(&hash_lock);
- list_for_each_entry(node, &tree->chunks, list) {
- struct audit_chunk *chunk = find_chunk(node);
- /* this could be NULL if the watch is dying else where... */
- struct inode *inode = chunk->mark.inode;
- node->index |= 1U<<31;
- if (iterate_mounts(compare_root, inode, root_mnt))
- node->index &= ~(1U<<31);
- }
- spin_unlock(&hash_lock);
- trim_marked(tree);
- drop_collected_mounts(root_mnt);
- skip_it:
- put_tree(tree);
- mutex_lock(&audit_filter_mutex);
- }
- list_del(&cursor);
- mutex_unlock(&audit_filter_mutex);
- }
- int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op)
- {
- if (pathname[0] != '/' ||
- rule->listnr != AUDIT_FILTER_EXIT ||
- op != Audit_equal ||
- rule->inode_f || rule->watch || rule->tree)
- return -EINVAL;
- rule->tree = alloc_tree(pathname);
- if (!rule->tree)
- return -ENOMEM;
- return 0;
- }
- void audit_put_tree(struct audit_tree *tree)
- {
- put_tree(tree);
- }
- static int tag_mount(struct vfsmount *mnt, void *arg)
- {
- return tag_chunk(d_backing_inode(mnt->mnt_root), arg);
- }
- /*
- * That gets run when evict_chunk() ends up needing to kill audit_tree.
- * Runs from a separate thread.
- */
- static int prune_tree_thread(void *unused)
- {
- for (;;) {
- set_current_state(TASK_INTERRUPTIBLE);
- if (list_empty(&prune_list))
- schedule();
- __set_current_state(TASK_RUNNING);
- mutex_lock(&audit_cmd_mutex);
- mutex_lock(&audit_filter_mutex);
- while (!list_empty(&prune_list)) {
- struct audit_tree *victim;
- victim = list_entry(prune_list.next,
- struct audit_tree, list);
- 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);
- }
- return 0;
- }
- static int audit_launch_prune(void)
- {
- if (prune_thread)
- return 0;
- prune_thread = kthread_create(prune_tree_thread, NULL,
- "audit_prune_tree");
- if (IS_ERR(prune_thread)) {
- pr_err("cannot start thread audit_prune_tree");
- prune_thread = NULL;
- return -ENOMEM;
- } else {
- wake_up_process(prune_thread);
- return 0;
- }
- }
- /* called with audit_filter_mutex */
- int audit_add_tree_rule(struct audit_krule *rule)
- {
- struct audit_tree *seed = rule->tree, *tree;
- struct path path;
- struct vfsmount *mnt;
- int err;
- rule->tree = NULL;
- list_for_each_entry(tree, &tree_list, list) {
- if (!strcmp(seed->pathname, tree->pathname)) {
- put_tree(seed);
- rule->tree = tree;
- list_add(&rule->rlist, &tree->rules);
- return 0;
- }
- }
- tree = seed;
- list_add(&tree->list, &tree_list);
- list_add(&rule->rlist, &tree->rules);
- /* do not set rule->tree yet */
- mutex_unlock(&audit_filter_mutex);
- if (unlikely(!prune_thread)) {
- err = audit_launch_prune();
- if (err)
- goto Err;
- }
- err = kern_path(tree->pathname, 0, &path);
- if (err)
- goto Err;
- mnt = collect_mounts(&path);
- path_put(&path);
- if (IS_ERR(mnt)) {
- err = PTR_ERR(mnt);
- goto Err;
- }
- get_tree(tree);
- err = iterate_mounts(tag_mount, tree, mnt);
- drop_collected_mounts(mnt);
- if (!err) {
- struct node *node;
- spin_lock(&hash_lock);
- list_for_each_entry(node, &tree->chunks, list)
- node->index &= ~(1U<<31);
- spin_unlock(&hash_lock);
- } else {
- trim_marked(tree);
- goto Err;
- }
- mutex_lock(&audit_filter_mutex);
- if (list_empty(&rule->rlist)) {
- put_tree(tree);
- return -ENOENT;
- }
- rule->tree = tree;
- put_tree(tree);
- return 0;
- Err:
- mutex_lock(&audit_filter_mutex);
- list_del_init(&tree->list);
- list_del_init(&tree->rules);
- put_tree(tree);
- return err;
- }
- int audit_tag_tree(char *old, char *new)
- {
- struct list_head cursor, barrier;
- int failed = 0;
- struct path path1, path2;
- struct vfsmount *tagged;
- int err;
- err = kern_path(new, 0, &path2);
- if (err)
- return err;
- tagged = collect_mounts(&path2);
- path_put(&path2);
- if (IS_ERR(tagged))
- return PTR_ERR(tagged);
- err = kern_path(old, 0, &path1);
- if (err) {
- drop_collected_mounts(tagged);
- return err;
- }
- mutex_lock(&audit_filter_mutex);
- list_add(&barrier, &tree_list);
- list_add(&cursor, &barrier);
- while (cursor.next != &tree_list) {
- struct audit_tree *tree;
- int good_one = 0;
- tree = container_of(cursor.next, struct audit_tree, list);
- get_tree(tree);
- list_del(&cursor);
- list_add(&cursor, &tree->list);
- mutex_unlock(&audit_filter_mutex);
- err = kern_path(tree->pathname, 0, &path2);
- if (!err) {
- good_one = path_is_under(&path1, &path2);
- path_put(&path2);
- }
- if (!good_one) {
- put_tree(tree);
- mutex_lock(&audit_filter_mutex);
- continue;
- }
- failed = iterate_mounts(tag_mount, tree, tagged);
- if (failed) {
- put_tree(tree);
- mutex_lock(&audit_filter_mutex);
- break;
- }
- mutex_lock(&audit_filter_mutex);
- spin_lock(&hash_lock);
- if (!tree->goner) {
- list_del(&tree->list);
- list_add(&tree->list, &tree_list);
- }
- spin_unlock(&hash_lock);
- put_tree(tree);
- }
- while (barrier.prev != &tree_list) {
- struct audit_tree *tree;
- tree = container_of(barrier.prev, struct audit_tree, list);
- get_tree(tree);
- list_del(&tree->list);
- list_add(&tree->list, &barrier);
- mutex_unlock(&audit_filter_mutex);
- if (!failed) {
- struct node *node;
- spin_lock(&hash_lock);
- list_for_each_entry(node, &tree->chunks, list)
- node->index &= ~(1U<<31);
- spin_unlock(&hash_lock);
- } else {
- trim_marked(tree);
- }
- put_tree(tree);
- mutex_lock(&audit_filter_mutex);
- }
- list_del(&barrier);
- list_del(&cursor);
- mutex_unlock(&audit_filter_mutex);
- path_put(&path1);
- drop_collected_mounts(tagged);
- return failed;
- }
- static void audit_schedule_prune(void)
- {
- wake_up_process(prune_thread);
- }
- /*
- * ... 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);
- }
- /*
- * Here comes the stuff asynchronous to auditctl operations
- */
- 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)
- return;
- chunk->dead = 1;
- mutex_lock(&audit_filter_mutex);
- spin_lock(&hash_lock);
- while (!list_empty(&chunk->trees)) {
- owner = list_entry(chunk->trees.next,
- struct audit_tree, same_root);
- owner->goner = 1;
- owner->root = NULL;
- list_del_init(&owner->same_root);
- spin_unlock(&hash_lock);
- 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);
- mutex_unlock(&audit_filter_mutex);
- if (need_prune)
- audit_schedule_prune();
- }
- static int audit_tree_handle_event(struct fsnotify_group *group,
- struct inode *to_tell,
- struct fsnotify_mark *inode_mark,
- struct fsnotify_mark *vfsmount_mark,
- u32 mask, void *data, int data_type,
- const unsigned char *file_name, u32 cookie)
- {
- return 0;
- }
- static void audit_tree_freeing_mark(struct fsnotify_mark *entry, struct fsnotify_group *group)
- {
- struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark);
- evict_chunk(chunk);
- /*
- * We are guaranteed to have at least one reference to the mark from
- * either the inode or the caller of fsnotify_destroy_mark().
- */
- BUG_ON(atomic_read(&entry->refcnt) < 1);
- }
- static const struct fsnotify_ops audit_tree_ops = {
- .handle_event = audit_tree_handle_event,
- .freeing_mark = audit_tree_freeing_mark,
- };
- static int __init audit_tree_init(void)
- {
- int i;
- audit_tree_group = fsnotify_alloc_group(&audit_tree_ops);
- if (IS_ERR(audit_tree_group))
- audit_panic("cannot initialize fsnotify group for rectree watches");
- for (i = 0; i < HASH_SIZE; i++)
- INIT_LIST_HEAD(&chunk_hash_heads[i]);
- return 0;
- }
- __initcall(audit_tree_init);
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