Merge tag 'fsnotify_for_v4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull fsnotify updates from Jan Kara:
 "Support for new FAN_OPEN_EXEC event and couple of cleanups around
  fsnotify"

* tag 'fsnotify_for_v4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fanotify: Use inode_is_open_for_write
  fanotify: Make sure to check event_len when copying
  fsnotify/fdinfo: include fdinfo.h for inotify_show_fdinfo()
  fanotify: introduce new event mask FAN_OPEN_EXEC_PERM
  fsnotify: refactor fsnotify_parent()/fsnotify() paired calls when event is on path
  fanotify: introduce new event mask FAN_OPEN_EXEC
  fanotify: return only user requested event types in event mask

4 files changed, 49 insertions, 30 deletions

diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
index a5a60691e48b..9e2142795335 100644
--- a/include/linux/fanotify.h
+++ b/include/linux/fanotify.h
@@ -37,10 +37,11 @@
 
 /* Events that user can request to be notified on */
 #define FANOTIFY_EVENTS		(FAN_ACCESS | FAN_MODIFY | \
-				 FAN_CLOSE | FAN_OPEN)
+				 FAN_CLOSE | FAN_OPEN | FAN_OPEN_EXEC)
 
 /* Events that require a permission response from user */
-#define FANOTIFY_PERM_EVENTS	(FAN_OPEN_PERM | FAN_ACCESS_PERM)
+#define FANOTIFY_PERM_EVENTS	(FAN_OPEN_PERM | FAN_ACCESS_PERM | \
+				 FAN_OPEN_EXEC_PERM)
 
 /* Extra flags that may be reported with event or control handling of events */
 #define FANOTIFY_EVENT_FLAGS	(FAN_EVENT_ON_CHILD | FAN_ONDIR)
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index fd1ce10553bf..2ccb08cb5d6a 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -26,30 +26,46 @@ static inline int fsnotify_parent(const struct path *path, struct dentry *dentry
 	return __fsnotify_parent(path, dentry, mask);
 }
 
-/* simple call site for access decisions */
+/*
+ * Simple wrapper to consolidate calls fsnotify_parent()/fsnotify() when
+ * an event is on a path.
+ */
+static inline int fsnotify_path(struct inode *inode, const struct path *path,
+				__u32 mask)
+{
+	int ret = fsnotify_parent(path, NULL, mask);
+
+	if (ret)
+		return ret;
+	return fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
+}
+
+/* Simple call site for access decisions */
 static inline int fsnotify_perm(struct file *file, int mask)
 {
+	int ret;
 	const struct path *path = &file->f_path;
 	struct inode *inode = file_inode(file);
 	__u32 fsnotify_mask = 0;
-	int ret;
 
 	if (file->f_mode & FMODE_NONOTIFY)
 		return 0;
 	if (!(mask & (MAY_READ | MAY_OPEN)))
 		return 0;
-	if (mask & MAY_OPEN)
+	if (mask & MAY_OPEN) {
 		fsnotify_mask = FS_OPEN_PERM;
-	else if (mask & MAY_READ)
-		fsnotify_mask = FS_ACCESS_PERM;
-	else
-		BUG();
 
-	ret = fsnotify_parent(path, NULL, fsnotify_mask);
-	if (ret)
-		return ret;
+		if (file->f_flags & __FMODE_EXEC) {
+			ret = fsnotify_path(inode, path, FS_OPEN_EXEC_PERM);
 
-	return fsnotify(inode, fsnotify_mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
+			if (ret)
+				return ret;
+		}
+	} else if (mask & MAY_READ) {
+		fsnotify_mask = FS_ACCESS_PERM;
+	}
+
+	return fsnotify_path(inode, path, fsnotify_mask);
 }
 
 /*
@@ -180,10 +196,8 @@ static inline void fsnotify_access(struct file *file)
 	if (S_ISDIR(inode->i_mode))
 		mask |= FS_ISDIR;
 
-	if (!(file->f_mode & FMODE_NONOTIFY)) {
-		fsnotify_parent(path, NULL, mask);
-		fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
-	}
+	if (!(file->f_mode & FMODE_NONOTIFY))
+		fsnotify_path(inode, path, mask);
 }
 
 /*
@@ -198,10 +212,8 @@ static inline void fsnotify_modify(struct file *file)
 	if (S_ISDIR(inode->i_mode))
 		mask |= FS_ISDIR;
 
-	if (!(file->f_mode & FMODE_NONOTIFY)) {
-		fsnotify_parent(path, NULL, mask);
-		fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
-	}
+	if (!(file->f_mode & FMODE_NONOTIFY))
+		fsnotify_path(inode, path, mask);
 }
 
 /*
@@ -215,9 +227,10 @@ static inline void fsnotify_open(struct file *file)
 
 	if (S_ISDIR(inode->i_mode))
 		mask |= FS_ISDIR;
+	if (file->f_flags & __FMODE_EXEC)
+		mask |= FS_OPEN_EXEC;
 
-	fsnotify_parent(path, NULL, mask);
-	fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
+	fsnotify_path(inode, path, mask);
 }
 
 /*
@@ -233,10 +246,8 @@ static inline void fsnotify_close(struct file *file)
 	if (S_ISDIR(inode->i_mode))
 		mask |= FS_ISDIR;
 
-	if (!(file->f_mode & FMODE_NONOTIFY)) {
-		fsnotify_parent(path, NULL, mask);
-		fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
-	}
+	if (!(file->f_mode & FMODE_NONOTIFY))
+		fsnotify_path(inode, path, mask);
 }
 
 /*
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 135b973e44d1..7639774e7475 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -38,6 +38,7 @@
 #define FS_DELETE		0x00000200	/* Subfile was deleted */
 #define FS_DELETE_SELF		0x00000400	/* Self was deleted */
 #define FS_MOVE_SELF		0x00000800	/* Self was moved */
+#define FS_OPEN_EXEC		0x00001000	/* File was opened for exec */
 
 #define FS_UNMOUNT		0x00002000	/* inode on umount fs */
 #define FS_Q_OVERFLOW		0x00004000	/* Event queued overflowed */
@@ -45,6 +46,7 @@
 
 #define FS_OPEN_PERM		0x00010000	/* open event in an permission hook */
 #define FS_ACCESS_PERM		0x00020000	/* access event in a permissions hook */
+#define FS_OPEN_EXEC_PERM	0x00040000	/* open/exec event in a permission hook */
 
 #define FS_EXCL_UNLINK		0x04000000	/* do not send events if object is unlinked */
 #define FS_ISDIR		0x40000000	/* event occurred against dir */
@@ -62,11 +64,13 @@
 #define FS_EVENTS_POSS_ON_CHILD   (FS_ACCESS | FS_MODIFY | FS_ATTRIB |\
 				   FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | FS_OPEN |\
 				   FS_MOVED_FROM | FS_MOVED_TO | FS_CREATE |\
-				   FS_DELETE | FS_OPEN_PERM | FS_ACCESS_PERM)
+				   FS_DELETE | FS_OPEN_PERM | FS_ACCESS_PERM | \
+				   FS_OPEN_EXEC | FS_OPEN_EXEC_PERM)
 
 #define FS_MOVE			(FS_MOVED_FROM | FS_MOVED_TO)
 
-#define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM)
+#define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM | \
+				  FS_OPEN_EXEC_PERM)
 
 /* Events that can be reported to backends */
 #define ALL_FSNOTIFY_EVENTS (FS_ACCESS | FS_MODIFY | FS_ATTRIB | \
@@ -74,7 +78,8 @@
 			     FS_MOVED_FROM | FS_MOVED_TO | FS_CREATE | \
 			     FS_DELETE | FS_DELETE_SELF | FS_MOVE_SELF | \
 			     FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED | \
-			     FS_OPEN_PERM | FS_ACCESS_PERM | FS_DN_RENAME)
+			     FS_OPEN_PERM | FS_ACCESS_PERM | FS_DN_RENAME | \
+			     FS_OPEN_EXEC | FS_OPEN_EXEC_PERM)
 
 /* Extra flags that may be reported with event or control handling of events */
 #define ALL_FSNOTIFY_FLAGS  (FS_EXCL_UNLINK | FS_ISDIR | FS_IN_ONESHOT | \
diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h
index b86740d1c50a..909c98fcace2 100644
--- a/include/uapi/linux/fanotify.h
+++ b/include/uapi/linux/fanotify.h
@@ -10,11 +10,13 @@
 #define FAN_CLOSE_WRITE		0x00000008	/* Writtable file closed */
 #define FAN_CLOSE_NOWRITE	0x00000010	/* Unwrittable file closed */
 #define FAN_OPEN		0x00000020	/* File was opened */
+#define FAN_OPEN_EXEC		0x00001000	/* File was opened for exec */
 
 #define FAN_Q_OVERFLOW		0x00004000	/* Event queued overflowed */
 
 #define FAN_OPEN_PERM		0x00010000	/* File open in perm check */
 #define FAN_ACCESS_PERM		0x00020000	/* File accessed in perm check */
+#define FAN_OPEN_EXEC_PERM	0x00040000	/* File open/exec in perm check */
 
 #define FAN_ONDIR		0x40000000	/* event occurred against dir */