Audit: clean up the audit_watch split

No real changes, just cleanup to the audit_watch split patch which we done
with minimal code changes for easy review.  Now fix interfaces to make
things work better.

Signed-off-by: Eric Paris <eparis@redhat.com>

5 files changed, 60 insertions, 67 deletions

diff --git a/kernel/audit.c b/kernel/audit.c
index c71bd26631a2..05a32f0d87dc 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -56,7 +56,6 @@
 #include <net/netlink.h>
 #include <linux/skbuff.h>
 #include <linux/netlink.h>
-#include <linux/inotify.h>
 #include <linux/freezer.h>
 #include <linux/tty.h>
 
diff --git a/kernel/audit.h b/kernel/audit.h
index 208687be4f30..82c8a09099f4 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -104,20 +104,15 @@ extern void audit_free_rule_rcu(struct rcu_head *);
 extern struct list_head audit_filter_list[];
 
 /* audit watch functions */
-extern unsigned long audit_watch_inode(struct audit_watch *watch);
-extern dev_t audit_watch_dev(struct audit_watch *watch);
 extern void audit_put_watch(struct audit_watch *watch);
 extern void audit_get_watch(struct audit_watch *watch);
 extern int audit_to_watch(struct audit_krule *krule, char *path, int len, u32 op);
-extern int audit_add_watch(struct audit_krule *krule);
-extern void audit_remove_watch(struct audit_watch *watch);
+extern int audit_add_watch(struct audit_krule *krule, struct list_head **list);
 extern void audit_remove_watch_rule(struct audit_krule *krule, struct list_head *list);
-extern void audit_inotify_unregister(struct list_head *in_list);
+extern void audit_watch_inotify_unregister(struct list_head *in_list);
 extern char *audit_watch_path(struct audit_watch *watch);
-extern struct list_head *audit_watch_rules(struct audit_watch *watch);
-
-extern struct audit_entry *audit_dupe_rule(struct audit_krule *old,
-                                           struct audit_watch *watch);
+extern int audit_watch_compare(struct audit_watch *watch, unsigned long ino, dev_t dev);
+extern struct audit_entry *audit_dupe_rule(struct audit_krule *old);
 
 #ifdef CONFIG_AUDIT_TREE
 extern struct audit_chunk *audit_tree_lookup(const struct inode *);
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index 8df43696f4ba..c2ca7168bfd1 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -51,12 +51,12 @@ struct audit_watch {
         unsigned long           ino;    /* associated inode number */
         struct audit_parent     *parent; /* associated parent */
         struct list_head        wlist;  /* entry in parent->watches list */
-        struct list_head        rules;  /* associated rules */
+        struct list_head        rules;  /* anchor for krule->rlist */
 };
 
 struct audit_parent {
-        struct list_head        ilist;  /* entry in inotify registration list */
-        struct list_head        watches; /* associated watches */
+        struct list_head        ilist;  /* tmp list used to free parents */
+        struct list_head        watches; /* anchor for audit_watch->wlist */
         struct inotify_watch    wdata;  /* inotify watch data */
         unsigned                flags;  /* status flags */
 };
@@ -78,13 +78,18 @@ struct inotify_handle *audit_ih;
 /* Inotify events we care about. */
 #define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF
 
-static void audit_free_parent(struct inotify_watch *i_watch)
+static void audit_free_parent(struct audit_parent *parent)
+{
+        WARN_ON(!list_empty(&parent->watches));
+        kfree(parent);
+}
+
+static void audit_destroy_watch(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);
+        audit_free_parent(parent);
 }
 
 void audit_get_watch(struct audit_watch *watch)
@@ -115,19 +120,11 @@ char *audit_watch_path(struct audit_watch *watch)
         return watch->path;
 }
 
-struct list_head *audit_watch_rules(struct audit_watch *watch)
+int audit_watch_compare(struct audit_watch *watch, unsigned long ino, dev_t dev)
 {
-        return &watch->rules;
-}
-
-unsigned long audit_watch_inode(struct audit_watch *watch)
-{
-        return watch->ino;
-}
-
-dev_t audit_watch_dev(struct audit_watch *watch)
-{
-        return watch->dev;
+        return (watch->ino != (unsigned long)-1) &&
+                (watch->ino == ino) &&
+                (watch->dev == dev);
 }
 
 /* Initialize a parent watch entry. */
@@ -149,7 +146,7 @@ static struct audit_parent *audit_init_parent(struct nameidata *ndp)
         wd = inotify_add_watch(audit_ih, &parent->wdata,
                                ndp->path.dentry->d_inode, AUDIT_IN_WATCH);
         if (wd < 0) {
-                audit_free_parent(&parent->wdata);
+                audit_free_parent(parent);
                 return ERR_PTR(wd);
         }
 
@@ -251,15 +248,19 @@ static void audit_update_watch(struct audit_parent *parent,
         struct audit_entry *oentry, *nentry;
 
         mutex_lock(&audit_filter_mutex);
+        /* Run all of the watches on this parent looking for the one that
+         * matches the given dname */
         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)
+                if (invalidating && !audit_dummy_context())
                         audit_filter_inodes(current, current->audit_context);
 
+                /* updating ino will likely change which audit_hash_list we
+                 * are on so we need a new watch for the new list */
                 nwatch = audit_dupe_watch(owatch);
                 if (IS_ERR(nwatch)) {
                         mutex_unlock(&audit_filter_mutex);
@@ -275,12 +276,21 @@ static void audit_update_watch(struct audit_parent *parent,
                         list_del(&oentry->rule.rlist);
                         list_del_rcu(&oentry->list);
 
-                        nentry = audit_dupe_rule(&oentry->rule, nwatch);
+                        nentry = audit_dupe_rule(&oentry->rule);
                         if (IS_ERR(nentry)) {
                                 list_del(&oentry->rule.list);
                                 audit_panic("error updating watch, removing");
                         } else {
                                 int h = audit_hash_ino((u32)ino);
+
+                                /*
+                                 * nentry->rule.watch == oentry->rule.watch so
+                                 * we must drop that reference and set it to our
+                                 * new watch.
+                                 */
+                                audit_put_watch(nentry->rule.watch);
+                                audit_get_watch(nwatch);
+                                nentry->rule.watch = nwatch;
                                 list_add(&nentry->rule.rlist, &nwatch->rules);
                                 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
                                 list_replace(&oentry->rule.list,
@@ -329,14 +339,14 @@ static void audit_remove_parent_watches(struct audit_parent *parent)
 
 /* Unregister inotify watches for parents on in_list.
  * Generates an IN_IGNORED event. */
-void audit_inotify_unregister(struct list_head *in_list)
+void audit_watch_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() */
+                /* the unpin matching the pin in audit_remove_watch_rule() */
                 unpin_inotify_watch(&p->wdata);
         }
 }
@@ -423,13 +433,13 @@ static void audit_add_to_parent(struct audit_krule *krule,
 
 /* Find a matching watch entry, or add this one.
  * Caller must hold audit_filter_mutex. */
-int audit_add_watch(struct audit_krule *krule)
+int audit_add_watch(struct audit_krule *krule, struct list_head **list)
 {
         struct audit_watch *watch = krule->watch;
         struct inotify_watch *i_watch;
         struct audit_parent *parent;
         struct nameidata *ndp = NULL, *ndw = NULL;
-        int ret = 0;
+        int h, ret = 0;
 
         mutex_unlock(&audit_filter_mutex);
 
@@ -475,6 +485,8 @@ int audit_add_watch(struct audit_krule *krule)
         /* match get in audit_init_parent or inotify_find_watch */
         put_inotify_watch(&parent->wdata);
 
+        h = audit_hash_ino((u32)watch->ino);
+        *list = &audit_inode_hash[h];
 error:
         audit_put_nd(ndp, ndw);         /* NULL args OK */
         return ret;
@@ -514,8 +526,7 @@ static void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
         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);
+                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 */
@@ -531,7 +542,7 @@ static void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
 
 static const struct inotify_operations audit_inotify_ops = {
         .handle_event   = audit_handle_ievent,
-        .destroy_watch  = audit_free_parent,
+        .destroy_watch  = audit_destroy_watch,
 };
 
 static int __init audit_watch_init(void)
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index ce08041f578d..ac87577f36b5 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -71,6 +71,7 @@ static inline void audit_free_rule(struct audit_entry *e)
 {
         int i;
         struct audit_krule *erule = &e->rule;
+
         /* some rules don't have associated watches */
         if (erule->watch)
                 audit_put_watch(erule->watch);
@@ -746,8 +747,7 @@ 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. */
-struct audit_entry *audit_dupe_rule(struct audit_krule *old,
-                                    struct audit_watch *watch)
+struct audit_entry *audit_dupe_rule(struct audit_krule *old)
 {
         u32 fcount = old->field_count;
         struct audit_entry *entry;
@@ -769,8 +769,8 @@ struct audit_entry *audit_dupe_rule(struct audit_krule *old,
         new->prio = old->prio;
         new->buflen = old->buflen;
         new->inode_f = old->inode_f;
-        new->watch = NULL;
         new->field_count = old->field_count;
+
         /*
          * note that we are OK with not refcounting here; audit_match_tree()
          * never dereferences tree and we can't get false positives there
@@ -811,9 +811,9 @@ struct audit_entry *audit_dupe_rule(struct audit_krule *old,
                 }
         }
 
-        if (watch) {
-                audit_get_watch(watch);
-                new->watch = watch;
+        if (old->watch) {
+                audit_get_watch(old->watch);
+                new->watch = old->watch;
         }
 
         return entry;
@@ -866,7 +866,7 @@ static inline int audit_add_rule(struct audit_entry *entry)
         struct audit_watch *watch = entry->rule.watch;
         struct audit_tree *tree = entry->rule.tree;
         struct list_head *list;
-        int h, err;
+        int err;
 #ifdef CONFIG_AUDITSYSCALL
         int dont_count = 0;
 
@@ -889,15 +889,11 @@ static inline int audit_add_rule(struct audit_entry *entry)
 
         if (watch) {
                 /* audit_filter_mutex is dropped and re-taken during this call */
-                err = audit_add_watch(&entry->rule);
+                err = audit_add_watch(&entry->rule, &list);
                 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)audit_watch_inode(watch));
-                list = &audit_inode_hash[h];
         }
         if (tree) {
                 err = audit_add_tree_rule(&entry->rule);
@@ -949,7 +945,7 @@ static inline int audit_del_rule(struct audit_entry *entry)
         struct audit_watch *watch = entry->rule.watch;
         struct audit_tree *tree = entry->rule.tree;
         struct list_head *list;
-        LIST_HEAD(inotify_list);
+        LIST_HEAD(inotify_unregister_list);
         int ret = 0;
 #ifdef CONFIG_AUDITSYSCALL
         int dont_count = 0;
@@ -969,7 +965,7 @@ static inline int audit_del_rule(struct audit_entry *entry)
         }
 
         if (e->rule.watch)
-                audit_remove_watch_rule(&e->rule, &inotify_list);
+                audit_remove_watch_rule(&e->rule, &inotify_unregister_list);
 
         if (e->rule.tree)
                 audit_remove_tree_rule(&e->rule);
@@ -987,8 +983,8 @@ static inline int audit_del_rule(struct audit_entry *entry)
 #endif
         mutex_unlock(&audit_filter_mutex);
 
-        if (!list_empty(&inotify_list))
-                audit_inotify_unregister(&inotify_list);
+        if (!list_empty(&inotify_unregister_list))
+                audit_watch_inotify_unregister(&inotify_unregister_list);
 
 out:
         if (watch)
@@ -1323,30 +1319,23 @@ static int update_lsm_rule(struct audit_krule *r)
 {
         struct audit_entry *entry = container_of(r, struct audit_entry, rule);
         struct audit_entry *nentry;
-        struct audit_watch *watch;
-        struct audit_tree *tree;
         int err = 0;
 
         if (!security_audit_rule_known(r))
                 return 0;
 
-        watch = r->watch;
-        tree = r->tree;
-        nentry = audit_dupe_rule(r, watch);
+        nentry = audit_dupe_rule(r);
         if (IS_ERR(nentry)) {
                 /* save the first error encountered for the
                  * return value */
                 err = PTR_ERR(nentry);
                 audit_panic("error updating LSM filters");
-                if (watch)
+                if (r->watch)
                         list_del(&r->rlist);
                 list_del_rcu(&entry->list);
                 list_del(&r->list);
         } else {
-                if (watch) {
-                        list_add(&nentry->rule.rlist, audit_watch_rules(watch));
-                        list_del(&r->rlist);
-                } else if (tree)
+                if (r->watch || r->tree)
                         list_replace_init(&r->rlist, &nentry->rule.rlist);
                 list_replace_rcu(&entry->list, &nentry->list);
                 list_replace(&r->list, &nentry->rule.list);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 3828ad5fb8f1..240063c370e6 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -549,9 +549,8 @@ static int audit_filter_rules(struct task_struct *tsk,
                         }
                         break;
                 case AUDIT_WATCH:
-                        if (name && audit_watch_inode(rule->watch) != (unsigned long)-1)
-                                result = (name->dev == audit_watch_dev(rule->watch) &&
-                                          name->ino == audit_watch_inode(rule->watch));
+                        if (name)
+                                result = audit_watch_compare(rule->watch, name->ino, name->dev);
                         break;
                 case AUDIT_DIR:
                         if (ctx)