sysfs: Rewrite binary file handling.

From Matthew Wilcox.

 - Remove sysfs_bin_buffer.  It's a security hole.
 - Remove checks for permissions; the VFS does that.
 - Validate offset & count at the top level.
 - Allow lower levels to return less data than was asked for.
 - Allocate buffer at open & free it at close, not on each read/write.

1 files changed, 2 insertions, 9 deletions

diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 3e9565e2abe1..d639e18caa91 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -16,18 +16,11 @@ struct attribute {
 	mode_t			mode;
 };
 
-struct sysfs_bin_buffer {
-	u8 * 	data;
-	size_t	size;
-	size_t	count;
-	loff_t	offset;
-};
-
 struct bin_attribute {
 	struct attribute	attr;
 	size_t			size;
-	ssize_t (*read)(struct kobject *, struct sysfs_bin_buffer *);
-	ssize_t (*write)(struct kobject *, struct sysfs_bin_buffer *);
+	ssize_t (*read)(struct kobject *, char *, loff_t, size_t);
+	ssize_t (*write)(struct kobject *, char *, loff_t, size_t);
 };
 
 struct sysfs_ops {