audit: make audit_inode take struct filename

Keep a pointer to the audit_names "slot" in struct filename.

Have all of the audit_inode callers pass a struct filename ponter to
audit_inode instead of a string pointer. If the aname field is already
populated, then we can skip walking the list altogether and just use it
directly.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

5 files changed, 42 insertions, 19 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 6bbd8fd..80b162b 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1999,8 +1999,7 @@ static int filename_lookup(int dfd, struct filename *name,
 						flags | LOOKUP_REVAL, nd);
 
 	if (likely(!retval))
-		audit_inode(name->name, nd->path.dentry,
-						flags & LOOKUP_PARENT);
+		audit_inode(name, nd->path.dentry, flags & LOOKUP_PARENT);
 	return retval;
 }
 
@@ -2674,7 +2673,6 @@ static int do_last(struct nameidata *nd, struct path *path,
 	struct path save_parent = { .dentry = NULL, .mnt = NULL };
 	bool retried = false;
 	int error;
-	const char *pathname = name->name;
 
 	nd->flags &= ~LOOKUP_PARENT;
 	nd->flags |= op->intent;
@@ -2690,7 +2688,7 @@ static int do_last(struct nameidata *nd, struct path *path,
 		error = complete_walk(nd);
 		if (error)
 			return error;
-		audit_inode(pathname, nd->path.dentry, 0);
+		audit_inode(name, nd->path.dentry, 0);
 		if (open_flag & O_CREAT) {
 			error = -EISDIR;
 			goto out;
@@ -2700,7 +2698,7 @@ static int do_last(struct nameidata *nd, struct path *path,
 		error = complete_walk(nd);
 		if (error)
 			return error;
-		audit_inode(pathname, dir, 0);
+		audit_inode(name, dir, 0);
 		goto finish_open;
 	}
 
@@ -2729,7 +2727,7 @@ static int do_last(struct nameidata *nd, struct path *path,
 		if (error)
 			return error;
 
-		audit_inode(pathname, dir, 0);
+		audit_inode(name, dir, 0);
 		error = -EISDIR;
 		/* trailing slashes? */
 		if (nd->last.name[nd->last.len])
@@ -2759,7 +2757,7 @@ retry_lookup:
 		    !S_ISREG(file->f_path.dentry->d_inode->i_mode))
 			will_truncate = false;
 
-		audit_inode(pathname, file->f_path.dentry, 0);
+		audit_inode(name, file->f_path.dentry, 0);
 		goto opened;
 	}
 
@@ -2776,7 +2774,7 @@ retry_lookup:
 	 * create/update audit record if it already exists.
 	 */
 	if (path->dentry->d_inode)
-		audit_inode(pathname, path->dentry, 0);
+		audit_inode(name, path->dentry, 0);
 
 	/*
 	 * If atomic_open() acquired write access it is dropped now due to
@@ -2841,7 +2839,7 @@ finish_lookup:
 	error = -ENOTDIR;
 	if ((nd->flags & LOOKUP_DIRECTORY) && !nd->inode->i_op->lookup)
 		goto out;
-	audit_inode(pathname, nd->path.dentry, 0);
+	audit_inode(name, nd->path.dentry, 0);
 finish_open:
 	if (!S_ISREG(nd->inode->i_mode))
 		will_truncate = false;
diff --git a/include/linux/audit.h b/include/linux/audit.h
index d5d7952..e5884f9 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -474,7 +474,7 @@ extern void __audit_syscall_exit(int ret_success, long ret_value);
 extern struct filename *__audit_reusename(const __user char *uptr);
 extern void __audit_getname(struct filename *name);
 extern void audit_putname(struct filename *name);
-extern void __audit_inode(const char *name, const struct dentry *dentry,
+extern void __audit_inode(struct filename *name, const struct dentry *dentry,
 				unsigned int parent);
 extern void __audit_inode_child(const struct inode *parent,
 				const struct dentry *dentry,
@@ -519,7 +519,7 @@ static inline void audit_getname(struct filename *name)
 	if (unlikely(!audit_dummy_context()))
 		__audit_getname(name);
 }
-static inline void audit_inode(const char *name, const struct dentry *dentry,
+static inline void audit_inode(struct filename *name, const struct dentry *dentry,
 				unsigned int parent) {
 	if (unlikely(!audit_dummy_context()))
 		__audit_inode(name, dentry, parent);
@@ -680,14 +680,16 @@ static inline void audit_getname(struct filename *name)
 { }
 static inline void audit_putname(struct filename *name)
 { }
-static inline void __audit_inode(const char *name, const struct dentry *dentry,
+static inline void __audit_inode(struct filename *name,
+					const struct dentry *dentry,
 					unsigned int parent)
 { }
 static inline void __audit_inode_child(const struct inode *parent,
 					const struct dentry *dentry,
 					const unsigned char type)
 { }
-static inline void audit_inode(const char *name, const struct dentry *dentry,
+static inline void audit_inode(struct filename *name,
+				const struct dentry *dentry,
 				unsigned int parent)
 { }
 static inline void audit_inode_child(const struct inode *parent,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index b6b10e7..4aa7160 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2196,9 +2196,11 @@ static inline int break_lease(struct inode *inode, unsigned int mode)
 #endif /* CONFIG_FILE_LOCKING */
 
 /* fs/open.c */
+struct audit_names;
 struct filename {
-	const char *name;		/* pointer to actual string */
-	const __user char *uptr;	/* original userland pointer */
+	const char		*name;	/* pointer to actual string */
+	const __user char	*uptr;	/* original userland pointer */
+	struct audit_names	*aname;
 };
 
 extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 6c5d9dc..71a3ca1 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -804,7 +804,7 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode,
 
 	if (oflag & O_CREAT) {
 		if (path.dentry->d_inode) {	/* entry already exists */
-			audit_inode(name->name, path.dentry, 0);
+			audit_inode(name, path.dentry, 0);
 			if (oflag & O_EXCL) {
 				error = -EEXIST;
 				goto out;
@@ -824,7 +824,7 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode,
 			error = -ENOENT;
 			goto out;
 		}
-		audit_inode(name->name, path.dentry, 0);
+		audit_inode(name, path.dentry, 0);
 		filp = do_open(&path, oflag);
 	}
 
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 521163a..2f186ed 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2076,6 +2076,7 @@ void __audit_getname(struct filename *name)
 	n->name = name;
 	n->name_len = AUDIT_NAME_FULL;
 	n->name_put = true;
+	name->aname = n;
 
 	if (!context->pwd.dentry)
 		get_fs_pwd(current->fs, &context->pwd);
@@ -2166,7 +2167,7 @@ static void audit_copy_inode(struct audit_names *name, const struct dentry *dent
  * @dentry: dentry being audited
  * @parent: does this dentry represent the parent?
  */
-void __audit_inode(const char *name, const struct dentry *dentry,
+void __audit_inode(struct filename *name, const struct dentry *dentry,
 		   unsigned int parent)
 {
 	struct audit_context *context = current->audit_context;
@@ -2179,9 +2180,29 @@ void __audit_inode(const char *name, const struct dentry *dentry,
 	if (!name)
 		goto out_alloc;
 
+#if AUDIT_DEBUG
+	/* The struct filename _must_ have a populated ->name */
+	BUG_ON(!name->name);
+#endif
+	/*
+	 * If we have a pointer to an audit_names entry already, then we can
+	 * just use it directly if the type is correct.
+	 */
+	n = name->aname;
+	if (n) {
+		if (parent) {
+			if (n->type == AUDIT_TYPE_PARENT ||
+			    n->type == AUDIT_TYPE_UNKNOWN)
+				goto out;
+		} else {
+			if (n->type != AUDIT_TYPE_PARENT)
+				goto out;
+		}
+	}
+
 	list_for_each_entry_reverse(n, &context->names_list, list) {
 		/* does the name pointer match? */
-		if (!n->name || n->name->name != name)
+		if (!n->name || n->name->name != name->name)
 			continue;
 
 		/* match the correct record type */