xfs: remove nr_to_write writeback windup.
[safe/jmp/linux-2.6] / kernel / auditfilter.c
index e7466dd..ce08041 100644 (file)
@@ -27,7 +27,7 @@
 #include <linux/namei.h>
 #include <linux/netlink.h>
 #include <linux/sched.h>
-#include <linux/inotify.h>
+#include <linux/slab.h>
 #include <linux/security.h>
 #include "audit.h"
 
  *             be written directly provided audit_filter_mutex is held.
  */
 
-/*
- * Reference counting:
- *
- * audit_parent: lifetime is from audit_init_parent() to receipt of an IN_IGNORED
- *     event.  Each audit_watch holds a reference to its associated parent.
- *
- * audit_watch: if added to lists, lifetime is from audit_init_watch() to
- *     audit_remove_watch().  Additionally, an audit_watch may exist
- *     temporarily to assist in searching existing filter data.  Each
- *     audit_krule holds a reference to its associated watch.
- */
-
-struct audit_parent {
-       struct list_head        ilist;  /* entry in inotify registration list */
-       struct list_head        watches; /* associated watches */
-       struct inotify_watch    wdata;  /* inotify watch data */
-       unsigned                flags;  /* status flags */
-};
-
-/*
- * audit_parent status flags:
- *
- * AUDIT_PARENT_INVALID - set anytime rules/watches are auto-removed due to
- * a filesystem event to ensure we're adding audit watches to a valid parent.
- * Technically not needed for IN_DELETE_SELF or IN_UNMOUNT events, as we cannot
- * receive them while we have nameidata, but must be used for IN_MOVE_SELF which
- * we can receive while holding nameidata.
- */
-#define AUDIT_PARENT_INVALID   0x001
-
 /* Audit filter lists, defined in <linux/audit.h> */
 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
        LIST_HEAD_INIT(audit_filter_list[0]),
@@ -97,41 +67,6 @@ static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
 
 DEFINE_MUTEX(audit_filter_mutex);
 
-/* Inotify events we care about. */
-#define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF
-
-void audit_free_parent(struct inotify_watch *i_watch)
-{
-       struct audit_parent *parent;
-
-       parent = container_of(i_watch, struct audit_parent, wdata);
-       WARN_ON(!list_empty(&parent->watches));
-       kfree(parent);
-}
-
-static inline void audit_get_watch(struct audit_watch *watch)
-{
-       atomic_inc(&watch->count);
-}
-
-static void audit_put_watch(struct audit_watch *watch)
-{
-       if (atomic_dec_and_test(&watch->count)) {
-               WARN_ON(watch->parent);
-               WARN_ON(!list_empty(&watch->rules));
-               kfree(watch->path);
-               kfree(watch);
-       }
-}
-
-static void audit_remove_watch(struct audit_watch *watch)
-{
-       list_del(&watch->wlist);
-       put_inotify_watch(&watch->parent->wdata);
-       watch->parent = NULL;
-       audit_put_watch(watch); /* match initial get */
-}
-
 static inline void audit_free_rule(struct audit_entry *e)
 {
        int i;
@@ -156,50 +91,6 @@ void audit_free_rule_rcu(struct rcu_head *head)
        audit_free_rule(e);
 }
 
-/* Initialize a parent watch entry. */
-static struct audit_parent *audit_init_parent(struct nameidata *ndp)
-{
-       struct audit_parent *parent;
-       s32 wd;
-
-       parent = kzalloc(sizeof(*parent), GFP_KERNEL);
-       if (unlikely(!parent))
-               return ERR_PTR(-ENOMEM);
-
-       INIT_LIST_HEAD(&parent->watches);
-       parent->flags = 0;
-
-       inotify_init_watch(&parent->wdata);
-       /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
-       get_inotify_watch(&parent->wdata);
-       wd = inotify_add_watch(audit_ih, &parent->wdata,
-                              ndp->path.dentry->d_inode, AUDIT_IN_WATCH);
-       if (wd < 0) {
-               audit_free_parent(&parent->wdata);
-               return ERR_PTR(wd);
-       }
-
-       return parent;
-}
-
-/* Initialize a watch entry. */
-static struct audit_watch *audit_init_watch(char *path)
-{
-       struct audit_watch *watch;
-
-       watch = kzalloc(sizeof(*watch), GFP_KERNEL);
-       if (unlikely(!watch))
-               return ERR_PTR(-ENOMEM);
-
-       INIT_LIST_HEAD(&watch->rules);
-       atomic_set(&watch->count, 1);
-       watch->path = path;
-       watch->dev = (dev_t)-1;
-       watch->ino = (unsigned long)-1;
-
-       return watch;
-}
-
 /* Initialize an audit filterlist entry. */
 static inline struct audit_entry *audit_init_entry(u32 field_count)
 {
@@ -260,31 +151,6 @@ static inline int audit_to_inode(struct audit_krule *krule,
        return 0;
 }
 
-/* Translate a watch string to kernel respresentation. */
-static int audit_to_watch(struct audit_krule *krule, char *path, int len,
-                         u32 op)
-{
-       struct audit_watch *watch;
-
-       if (!audit_ih)
-               return -EOPNOTSUPP;
-
-       if (path[0] != '/' || path[len-1] == '/' ||
-           krule->listnr != AUDIT_FILTER_EXIT ||
-           op != Audit_equal ||
-           krule->inode_f || krule->watch || krule->tree)
-               return -EINVAL;
-
-       watch = audit_init_watch(path);
-       if (IS_ERR(watch))
-               return PTR_ERR(watch);
-
-       audit_get_watch(watch);
-       krule->watch = watch;
-
-       return 0;
-}
-
 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
 
 int __init audit_register_class(int class, unsigned *list)
@@ -766,7 +632,8 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
                        break;
                case AUDIT_WATCH:
                        data->buflen += data->values[i] =
-                               audit_pack_string(&bufp, krule->watch->path);
+                               audit_pack_string(&bufp,
+                                                 audit_watch_path(krule->watch));
                        break;
                case AUDIT_DIR:
                        data->buflen += data->values[i] =
@@ -818,7 +685,8 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
                                return 1;
                        break;
                case AUDIT_WATCH:
-                       if (strcmp(a->watch->path, b->watch->path))
+                       if (strcmp(audit_watch_path(a->watch),
+                                  audit_watch_path(b->watch)))
                                return 1;
                        break;
                case AUDIT_DIR:
@@ -844,32 +712,6 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
        return 0;
 }
 
-/* Duplicate the given audit watch.  The new watch's rules list is initialized
- * to an empty list and wlist is undefined. */
-static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
-{
-       char *path;
-       struct audit_watch *new;
-
-       path = kstrdup(old->path, GFP_KERNEL);
-       if (unlikely(!path))
-               return ERR_PTR(-ENOMEM);
-
-       new = audit_init_watch(path);
-       if (IS_ERR(new)) {
-               kfree(path);
-               goto out;
-       }
-
-       new->dev = old->dev;
-       new->ino = old->ino;
-       get_inotify_watch(&old->parent->wdata);
-       new->parent = old->parent;
-
-out:
-       return new;
-}
-
 /* Duplicate LSM field information.  The lsm_rule is opaque, so must be
  * re-initialized. */
 static inline int audit_dupe_lsm_field(struct audit_field *df,
@@ -904,8 +746,8 @@ static inline int audit_dupe_lsm_field(struct audit_field *df,
  * rule with the new rule in the filterlist, then free the old rule.
  * The rlist element is undefined; list manipulations are handled apart from
  * the initial copy. */
-static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
-                                          struct audit_watch *watch)
+struct audit_entry *audit_dupe_rule(struct audit_krule *old,
+                                   struct audit_watch *watch)
 {
        u32 fcount = old->field_count;
        struct audit_entry *entry;
@@ -977,127 +819,6 @@ static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
        return entry;
 }
 
-static void audit_watch_log_rule_change(struct audit_krule *r, struct audit_watch *w, char *op)
-{
-       if (audit_enabled) {
-               struct audit_buffer *ab;
-               ab = audit_log_start(NULL, GFP_NOFS, AUDIT_CONFIG_CHANGE);
-               audit_log_format(ab, "auid=%u ses=%u op=",
-                                audit_get_loginuid(current),
-                                audit_get_sessionid(current));
-               audit_log_string(ab, op);
-               audit_log_format(ab, " path=");
-               audit_log_untrustedstring(ab, w->path);
-               if (r->filterkey) {
-                       audit_log_format(ab, " key=");
-                       audit_log_untrustedstring(ab, r->filterkey);
-               } else
-                       audit_log_format(ab, " key=(null)");
-               audit_log_format(ab, " list=%d res=1", r->listnr);
-               audit_log_end(ab);
-       }
-}
-
-/* Update inode info in audit rules based on filesystem event. */
-static void audit_update_watch(struct audit_parent *parent,
-                              const char *dname, dev_t dev,
-                              unsigned long ino, unsigned invalidating)
-{
-       struct audit_watch *owatch, *nwatch, *nextw;
-       struct audit_krule *r, *nextr;
-       struct audit_entry *oentry, *nentry;
-
-       mutex_lock(&audit_filter_mutex);
-       list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
-               if (audit_compare_dname_path(dname, owatch->path, NULL))
-                       continue;
-
-               /* If the update involves invalidating rules, do the inode-based
-                * filtering now, so we don't omit records. */
-               if (invalidating && current->audit_context)
-                       audit_filter_inodes(current, current->audit_context);
-
-               nwatch = audit_dupe_watch(owatch);
-               if (IS_ERR(nwatch)) {
-                       mutex_unlock(&audit_filter_mutex);
-                       audit_panic("error updating watch, skipping");
-                       return;
-               }
-               nwatch->dev = dev;
-               nwatch->ino = ino;
-
-               list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
-
-                       oentry = container_of(r, struct audit_entry, rule);
-                       list_del(&oentry->rule.rlist);
-                       list_del_rcu(&oentry->list);
-
-                       nentry = audit_dupe_rule(&oentry->rule, nwatch);
-                       if (IS_ERR(nentry)) {
-                               list_del(&oentry->rule.list);
-                               audit_panic("error updating watch, removing");
-                       } else {
-                               int h = audit_hash_ino((u32)ino);
-                               list_add(&nentry->rule.rlist, &nwatch->rules);
-                               list_add_rcu(&nentry->list, &audit_inode_hash[h]);
-                               list_replace(&oentry->rule.list,
-                                            &nentry->rule.list);
-                       }
-
-                       audit_watch_log_rule_change(r, owatch, "updated rules");
-
-                       call_rcu(&oentry->rcu, audit_free_rule_rcu);
-               }
-
-               audit_remove_watch(owatch);
-               goto add_watch_to_parent; /* event applies to a single watch */
-       }
-       mutex_unlock(&audit_filter_mutex);
-       return;
-
-add_watch_to_parent:
-       list_add(&nwatch->wlist, &parent->watches);
-       mutex_unlock(&audit_filter_mutex);
-       return;
-}
-
-/* Remove all watches & rules associated with a parent that is going away. */
-static void audit_remove_parent_watches(struct audit_parent *parent)
-{
-       struct audit_watch *w, *nextw;
-       struct audit_krule *r, *nextr;
-       struct audit_entry *e;
-
-       mutex_lock(&audit_filter_mutex);
-       parent->flags |= AUDIT_PARENT_INVALID;
-       list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
-               list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
-                       e = container_of(r, struct audit_entry, rule);
-                       audit_watch_log_rule_change(r, w, "remove rule");
-                       list_del(&r->rlist);
-                       list_del(&r->list);
-                       list_del_rcu(&e->list);
-                       call_rcu(&e->rcu, audit_free_rule_rcu);
-               }
-               audit_remove_watch(w);
-       }
-       mutex_unlock(&audit_filter_mutex);
-}
-
-/* Unregister inotify watches for parents on in_list.
- * Generates an IN_IGNORED event. */
-static void audit_inotify_unregister(struct list_head *in_list)
-{
-       struct audit_parent *p, *n;
-
-       list_for_each_entry_safe(p, n, in_list, ilist) {
-               list_del(&p->ilist);
-               inotify_rm_watch(audit_ih, &p->wdata);
-               /* the unpin matching the pin in audit_do_del_rule() */
-               unpin_inotify_watch(&p->wdata);
-       }
-}
-
 /* Find an existing audit rule.
  * Caller must hold audit_filter_mutex to prevent stale rule data. */
 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
@@ -1135,134 +856,6 @@ out:
        return found;
 }
 
-/* Get path information necessary for adding watches. */
-static int audit_get_nd(char *path, struct nameidata **ndp,
-                       struct nameidata **ndw)
-{
-       struct nameidata *ndparent, *ndwatch;
-       int err;
-
-       ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
-       if (unlikely(!ndparent))
-               return -ENOMEM;
-
-       ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
-       if (unlikely(!ndwatch)) {
-               kfree(ndparent);
-               return -ENOMEM;
-       }
-
-       err = path_lookup(path, LOOKUP_PARENT, ndparent);
-       if (err) {
-               kfree(ndparent);
-               kfree(ndwatch);
-               return err;
-       }
-
-       err = path_lookup(path, 0, ndwatch);
-       if (err) {
-               kfree(ndwatch);
-               ndwatch = NULL;
-       }
-
-       *ndp = ndparent;
-       *ndw = ndwatch;
-
-       return 0;
-}
-
-/* Release resources used for watch path information. */
-static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
-{
-       if (ndp) {
-               path_put(&ndp->path);
-               kfree(ndp);
-       }
-       if (ndw) {
-               path_put(&ndw->path);
-               kfree(ndw);
-       }
-}
-
-/* Associate the given rule with an existing parent inotify_watch.
- * Caller must hold audit_filter_mutex. */
-static void audit_add_to_parent(struct audit_krule *krule,
-                               struct audit_parent *parent)
-{
-       struct audit_watch *w, *watch = krule->watch;
-       int watch_found = 0;
-
-       list_for_each_entry(w, &parent->watches, wlist) {
-               if (strcmp(watch->path, w->path))
-                       continue;
-
-               watch_found = 1;
-
-               /* put krule's and initial refs to temporary watch */
-               audit_put_watch(watch);
-               audit_put_watch(watch);
-
-               audit_get_watch(w);
-               krule->watch = watch = w;
-               break;
-       }
-
-       if (!watch_found) {
-               get_inotify_watch(&parent->wdata);
-               watch->parent = parent;
-
-               list_add(&watch->wlist, &parent->watches);
-       }
-       list_add(&krule->rlist, &watch->rules);
-}
-
-/* Find a matching watch entry, or add this one.
- * Caller must hold audit_filter_mutex. */
-static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
-                          struct nameidata *ndw)
-{
-       struct audit_watch *watch = krule->watch;
-       struct inotify_watch *i_watch;
-       struct audit_parent *parent;
-       int ret = 0;
-
-       /* update watch filter fields */
-       if (ndw) {
-               watch->dev = ndw->path.dentry->d_inode->i_sb->s_dev;
-               watch->ino = ndw->path.dentry->d_inode->i_ino;
-       }
-
-       /* The audit_filter_mutex must not be held during inotify calls because
-        * we hold it during inotify event callback processing.  If an existing
-        * inotify watch is found, inotify_find_watch() grabs a reference before
-        * returning.
-        */
-       mutex_unlock(&audit_filter_mutex);
-
-       if (inotify_find_watch(audit_ih, ndp->path.dentry->d_inode,
-                              &i_watch) < 0) {
-               parent = audit_init_parent(ndp);
-               if (IS_ERR(parent)) {
-                       /* caller expects mutex locked */
-                       mutex_lock(&audit_filter_mutex);
-                       return PTR_ERR(parent);
-               }
-       } else
-               parent = container_of(i_watch, struct audit_parent, wdata);
-
-       mutex_lock(&audit_filter_mutex);
-
-       /* parent was moved before we took audit_filter_mutex */
-       if (parent->flags & AUDIT_PARENT_INVALID)
-               ret = -ENOENT;
-       else
-               audit_add_to_parent(krule, parent);
-
-       /* match get in audit_init_parent or inotify_find_watch */
-       put_inotify_watch(&parent->wdata);
-       return ret;
-}
-
 static u64 prio_low = ~0ULL/2;
 static u64 prio_high = ~0ULL/2 - 1;
 
@@ -1272,7 +865,6 @@ static inline int audit_add_rule(struct audit_entry *entry)
        struct audit_entry *e;
        struct audit_watch *watch = entry->rule.watch;
        struct audit_tree *tree = entry->rule.tree;
-       struct nameidata *ndp = NULL, *ndw = NULL;
        struct list_head *list;
        int h, err;
 #ifdef CONFIG_AUDITSYSCALL
@@ -1286,8 +878,8 @@ static inline int audit_add_rule(struct audit_entry *entry)
 
        mutex_lock(&audit_filter_mutex);
        e = audit_find_rule(entry, &list);
-       mutex_unlock(&audit_filter_mutex);
        if (e) {
+               mutex_unlock(&audit_filter_mutex);
                err = -EEXIST;
                /* normally audit_add_tree_rule() will free it on failure */
                if (tree)
@@ -1295,24 +887,16 @@ static inline int audit_add_rule(struct audit_entry *entry)
                goto error;
        }
 
-       /* Avoid calling path_lookup under audit_filter_mutex. */
-       if (watch) {
-               err = audit_get_nd(watch->path, &ndp, &ndw);
-               if (err)
-                       goto error;
-       }
-
-       mutex_lock(&audit_filter_mutex);
        if (watch) {
                /* audit_filter_mutex is dropped and re-taken during this call */
-               err = audit_add_watch(&entry->rule, ndp, ndw);
+               err = audit_add_watch(&entry->rule);
                if (err) {
                        mutex_unlock(&audit_filter_mutex);
                        goto error;
                }
                /* entry->rule.watch may have changed during audit_add_watch() */
                watch = entry->rule.watch;
-               h = audit_hash_ino((u32)watch->ino);
+               h = audit_hash_ino((u32)audit_watch_inode(watch));
                list = &audit_inode_hash[h];
        }
        if (tree) {
@@ -1350,11 +934,9 @@ static inline int audit_add_rule(struct audit_entry *entry)
 #endif
        mutex_unlock(&audit_filter_mutex);
 
-       audit_put_nd(ndp, ndw);         /* NULL args OK */
        return 0;
 
 error:
-       audit_put_nd(ndp, ndw);         /* NULL args OK */
        if (watch)
                audit_put_watch(watch); /* tmp watch, matches initial get */
        return err;
@@ -1364,7 +946,7 @@ error:
 static inline int audit_del_rule(struct audit_entry *entry)
 {
        struct audit_entry  *e;
-       struct audit_watch *watch, *tmp_watch = entry->rule.watch;
+       struct audit_watch *watch = entry->rule.watch;
        struct audit_tree *tree = entry->rule.tree;
        struct list_head *list;
        LIST_HEAD(inotify_list);
@@ -1386,29 +968,8 @@ static inline int audit_del_rule(struct audit_entry *entry)
                goto out;
        }
 
-       watch = e->rule.watch;
-       if (watch) {
-               struct audit_parent *parent = watch->parent;
-
-               list_del(&e->rule.rlist);
-
-               if (list_empty(&watch->rules)) {
-                       audit_remove_watch(watch);
-
-                       if (list_empty(&parent->watches)) {
-                               /* Put parent on the inotify un-registration
-                                * list.  Grab a reference before releasing
-                                * audit_filter_mutex, to be released in
-                                * audit_inotify_unregister().
-                                * If filesystem is going away, just leave
-                                * the sucker alone, eviction will take
-                                * care of it.
-                                */
-                               if (pin_inotify_watch(&parent->wdata))
-                                       list_add(&parent->ilist, &inotify_list);
-                       }
-               }
-       }
+       if (e->rule.watch)
+               audit_remove_watch_rule(&e->rule, &inotify_list);
 
        if (e->rule.tree)
                audit_remove_tree_rule(&e->rule);
@@ -1430,8 +991,8 @@ static inline int audit_del_rule(struct audit_entry *entry)
                audit_inotify_unregister(&inotify_list);
 
 out:
-       if (tmp_watch)
-               audit_put_watch(tmp_watch); /* match initial get */
+       if (watch)
+               audit_put_watch(watch); /* match initial get */
        if (tree)
                audit_put_tree(tree);   /* that's the temporary one */
 
@@ -1519,11 +1080,9 @@ static void audit_log_rule_change(uid_t loginuid, u32 sessionid, u32 sid,
                        security_release_secctx(ctx, len);
                }
        }
-       audit_log_format(ab, " op=%s rule key=", action);
-       if (rule->filterkey)
-               audit_log_untrustedstring(ab, rule->filterkey);
-       else
-               audit_log_format(ab, "(null)");
+       audit_log_format(ab, " op=");
+       audit_log_string(ab, action);
+       audit_log_key(ab, rule->filterkey);
        audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
        audit_log_end(ab);
 }
@@ -1587,7 +1146,7 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
                        return PTR_ERR(entry);
 
                err = audit_add_rule(entry);
-               audit_log_rule_change(loginuid, sessionid, sid, "add",
+               audit_log_rule_change(loginuid, sessionid, sid, "add rule",
                                      &entry->rule, !err);
 
                if (err)
@@ -1603,7 +1162,7 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
                        return PTR_ERR(entry);
 
                err = audit_del_rule(entry);
-               audit_log_rule_change(loginuid, sessionid, sid, "remove",
+               audit_log_rule_change(loginuid, sessionid, sid, "remove rule",
                                      &entry->rule, !err);
 
                audit_free_rule(entry);
@@ -1785,7 +1344,7 @@ static int update_lsm_rule(struct audit_krule *r)
                list_del(&r->list);
        } else {
                if (watch) {
-                       list_add(&nentry->rule.rlist, &watch->rules);
+                       list_add(&nentry->rule.rlist, audit_watch_rules(watch));
                        list_del(&r->rlist);
                } else if (tree)
                        list_replace_init(&r->rlist, &nentry->rule.rlist);
@@ -1821,27 +1380,3 @@ int audit_update_lsm_rules(void)
 
        return err;
 }
-
-/* Update watch data in audit rules based on inotify events. */
-void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
-                        u32 cookie, const char *dname, struct inode *inode)
-{
-       struct audit_parent *parent;
-
-       parent = container_of(i_watch, struct audit_parent, wdata);
-
-       if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
-               audit_update_watch(parent, dname, inode->i_sb->s_dev,
-                                  inode->i_ino, 0);
-       else if (mask & (IN_DELETE|IN_MOVED_FROM))
-               audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
-       /* inotify automatically removes the watch and sends IN_IGNORED */
-       else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
-               audit_remove_parent_watches(parent);
-       /* inotify does not remove the watch, so remove it manually */
-       else if(mask & IN_MOVE_SELF) {
-               audit_remove_parent_watches(parent);
-               inotify_remove_watch_locked(audit_ih, i_watch);
-       } else if (mask & IN_IGNORED)
-               put_inotify_watch(i_watch);
-}