1 files changed, 131 insertions, 11 deletions

diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index d25f500bf7e7..a3d5b751cac5 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -40,15 +40,45 @@ struct fanotify_fh {
 struct fanotify_info {
 	/* size of dir_fh/file_fh including fanotify_fh hdr size */
 	u8 dir_fh_totlen;
+	u8 dir2_fh_totlen;
 	u8 file_fh_totlen;
 	u8 name_len;
-	u8 pad;
+	u8 name2_len;
+	u8 pad[3];
 	unsigned char buf[];
 	/*
 	 * (struct fanotify_fh) dir_fh starts at buf[0]
-	 * (optional) file_fh starts at buf[dir_fh_totlen]
-	 * name starts at buf[dir_fh_totlen + file_fh_totlen]
+	 * (optional) dir2_fh starts at buf[dir_fh_totlen]
+	 * (optional) file_fh starts at buf[dir_fh_totlen + dir2_fh_totlen]
+	 * name starts at buf[dir_fh_totlen + dir2_fh_totlen + file_fh_totlen]
+	 * ...
 	 */
+#define FANOTIFY_DIR_FH_SIZE(info)	((info)->dir_fh_totlen)
+#define FANOTIFY_DIR2_FH_SIZE(info)	((info)->dir2_fh_totlen)
+#define FANOTIFY_FILE_FH_SIZE(info)	((info)->file_fh_totlen)
+#define FANOTIFY_NAME_SIZE(info)	((info)->name_len + 1)
+#define FANOTIFY_NAME2_SIZE(info)	((info)->name2_len + 1)
+
+#define FANOTIFY_DIR_FH_OFFSET(info)	0
+#define FANOTIFY_DIR2_FH_OFFSET(info) \
+	(FANOTIFY_DIR_FH_OFFSET(info) + FANOTIFY_DIR_FH_SIZE(info))
+#define FANOTIFY_FILE_FH_OFFSET(info) \
+	(FANOTIFY_DIR2_FH_OFFSET(info) + FANOTIFY_DIR2_FH_SIZE(info))
+#define FANOTIFY_NAME_OFFSET(info) \
+	(FANOTIFY_FILE_FH_OFFSET(info) + FANOTIFY_FILE_FH_SIZE(info))
+#define FANOTIFY_NAME2_OFFSET(info) \
+	(FANOTIFY_NAME_OFFSET(info) + FANOTIFY_NAME_SIZE(info))
+
+#define FANOTIFY_DIR_FH_BUF(info) \
+	((info)->buf + FANOTIFY_DIR_FH_OFFSET(info))
+#define FANOTIFY_DIR2_FH_BUF(info) \
+	((info)->buf + FANOTIFY_DIR2_FH_OFFSET(info))
+#define FANOTIFY_FILE_FH_BUF(info) \
+	((info)->buf + FANOTIFY_FILE_FH_OFFSET(info))
+#define FANOTIFY_NAME_BUF(info) \
+	((info)->buf + FANOTIFY_NAME_OFFSET(info))
+#define FANOTIFY_NAME2_BUF(info) \
+	((info)->buf + FANOTIFY_NAME2_OFFSET(info))
 } __aligned(4);
 
 static inline bool fanotify_fh_has_ext_buf(struct fanotify_fh *fh)
@@ -87,7 +117,21 @@ static inline struct fanotify_fh *fanotify_info_dir_fh(struct fanotify_info *inf
 {
 	BUILD_BUG_ON(offsetof(struct fanotify_info, buf) % 4);
 
-	return (struct fanotify_fh *)info->buf;
+	return (struct fanotify_fh *)FANOTIFY_DIR_FH_BUF(info);
+}
+
+static inline int fanotify_info_dir2_fh_len(struct fanotify_info *info)
+{
+	if (!info->dir2_fh_totlen ||
+	    WARN_ON_ONCE(info->dir2_fh_totlen < FANOTIFY_FH_HDR_LEN))
+		return 0;
+
+	return info->dir2_fh_totlen - FANOTIFY_FH_HDR_LEN;
+}
+
+static inline struct fanotify_fh *fanotify_info_dir2_fh(struct fanotify_info *info)
+{
+	return (struct fanotify_fh *)FANOTIFY_DIR2_FH_BUF(info);
 }
 
 static inline int fanotify_info_file_fh_len(struct fanotify_info *info)
@@ -101,32 +145,90 @@ static inline int fanotify_info_file_fh_len(struct fanotify_info *info)
 
 static inline struct fanotify_fh *fanotify_info_file_fh(struct fanotify_info *info)
 {
-	return (struct fanotify_fh *)(info->buf + info->dir_fh_totlen);
+	return (struct fanotify_fh *)FANOTIFY_FILE_FH_BUF(info);
 }
 
-static inline const char *fanotify_info_name(struct fanotify_info *info)
+static inline char *fanotify_info_name(struct fanotify_info *info)
 {
-	return info->buf + info->dir_fh_totlen + info->file_fh_totlen;
+	if (!info->name_len)
+		return NULL;
+
+	return FANOTIFY_NAME_BUF(info);
+}
+
+static inline char *fanotify_info_name2(struct fanotify_info *info)
+{
+	if (!info->name2_len)
+		return NULL;
+
+	return FANOTIFY_NAME2_BUF(info);
 }
 
 static inline void fanotify_info_init(struct fanotify_info *info)
 {
+	BUILD_BUG_ON(FANOTIFY_FH_HDR_LEN + MAX_HANDLE_SZ > U8_MAX);
+	BUILD_BUG_ON(NAME_MAX > U8_MAX);
+
 	info->dir_fh_totlen = 0;
+	info->dir2_fh_totlen = 0;
 	info->file_fh_totlen = 0;
 	info->name_len = 0;
+	info->name2_len = 0;
+}
+
+/* These set/copy helpers MUST be called by order */
+static inline void fanotify_info_set_dir_fh(struct fanotify_info *info,
+					    unsigned int totlen)
+{
+	if (WARN_ON_ONCE(info->dir2_fh_totlen > 0) ||
+	    WARN_ON_ONCE(info->file_fh_totlen > 0) ||
+	    WARN_ON_ONCE(info->name_len > 0) ||
+	    WARN_ON_ONCE(info->name2_len > 0))
+		return;
+
+	info->dir_fh_totlen = totlen;
 }
 
-static inline unsigned int fanotify_info_len(struct fanotify_info *info)
+static inline void fanotify_info_set_dir2_fh(struct fanotify_info *info,
+					     unsigned int totlen)
 {
-	return info->dir_fh_totlen + info->file_fh_totlen + info->name_len;
+	if (WARN_ON_ONCE(info->file_fh_totlen > 0) ||
+	    WARN_ON_ONCE(info->name_len > 0) ||
+	    WARN_ON_ONCE(info->name2_len > 0))
+		return;
+
+	info->dir2_fh_totlen = totlen;
+}
+
+static inline void fanotify_info_set_file_fh(struct fanotify_info *info,
+					     unsigned int totlen)
+{
+	if (WARN_ON_ONCE(info->name_len > 0) ||
+	    WARN_ON_ONCE(info->name2_len > 0))
+		return;
+
+	info->file_fh_totlen = totlen;
 }
 
 static inline void fanotify_info_copy_name(struct fanotify_info *info,
 					   const struct qstr *name)
 {
+	if (WARN_ON_ONCE(name->len > NAME_MAX) ||
+	    WARN_ON_ONCE(info->name2_len > 0))
+		return;
+
 	info->name_len = name->len;
-	strcpy(info->buf + info->dir_fh_totlen + info->file_fh_totlen,
-	       name->name);
+	strcpy(fanotify_info_name(info), name->name);
+}
+
+static inline void fanotify_info_copy_name2(struct fanotify_info *info,
+					    const struct qstr *name)
+{
+	if (WARN_ON_ONCE(name->len > NAME_MAX))
+		return;
+
+	info->name2_len = name->len;
+	strcpy(fanotify_info_name2(info), name->name);
 }
 
 /*
@@ -271,6 +373,13 @@ static inline int fanotify_event_dir_fh_len(struct fanotify_event *event)
 	return info ? fanotify_info_dir_fh_len(info) : 0;
 }
 
+static inline int fanotify_event_dir2_fh_len(struct fanotify_event *event)
+{
+	struct fanotify_info *info = fanotify_event_info(event);
+
+	return info ? fanotify_info_dir2_fh_len(info) : 0;
+}
+
 static inline bool fanotify_event_has_object_fh(struct fanotify_event *event)
 {
 	/* For error events, even zeroed fh are reported. */
@@ -284,6 +393,17 @@ static inline bool fanotify_event_has_dir_fh(struct fanotify_event *event)
 	return fanotify_event_dir_fh_len(event) > 0;
 }
 
+static inline bool fanotify_event_has_dir2_fh(struct fanotify_event *event)
+{
+	return fanotify_event_dir2_fh_len(event) > 0;
+}
+
+static inline bool fanotify_event_has_any_dir_fh(struct fanotify_event *event)
+{
+	return fanotify_event_has_dir_fh(event) ||
+		fanotify_event_has_dir2_fh(event);
+}
+
 struct fanotify_path_event {
 	struct fanotify_event fae;
 	struct path path;