From 99b76233803beab302123d243eea9e41149804f3 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Wed, 25 Mar 2009 22:48:06 +0300 Subject: proc 2/2: remove struct proc_dir_entry::owner Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy as correctly noted at bug #12454. Someone can lookup entry with NULL ->owner, thus not pinning enything, and release it later resulting in module refcount underflow. We can keep ->owner and supply it at registration time like ->proc_fops and ->data. But this leaves ->owner as easy-manipulative field (just one C assignment) and somebody will forget to unpin previous/pin current module when switching ->owner. ->proc_fops is declared as "const" which should give some thoughts. ->read_proc/->write_proc were just fixed to not require ->owner for protection. rmmod'ed directories will be empty and return "." and ".." -- no harm. And directories with tricky enough readdir and lookup shouldn't be modular. We definitely don't want such modular code. Removing ->owner will also make PDE smaller. So, let's nuke it. Kudos to Jeff Layton for reminding about this, let's say, oversight. http://bugzilla.kernel.org/show_bug.cgi?id=12454 Signed-off-by: Alexey Dobriyan --- include/linux/proc_fs.h | 4 ---- 1 file changed, 4 deletions(-) (limited to 'include/linux/proc_fs.h') diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index b8bdb96eff78..fbfa3d44d33d 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -41,9 +41,6 @@ enum { * while parent/subdir create the directory structure (every * /proc file has a parent, but "subdir" is NULL for all * non-directory entries). - * - * "owner" is used to protect module - * from unloading while proc_dir_entry is in use */ typedef int (read_proc_t)(char *page, char **start, off_t off, @@ -70,7 +67,6 @@ struct proc_dir_entry { * somewhere. */ const struct file_operations *proc_fops; - struct module *owner; struct proc_dir_entry *next, *parent, *subdir; void *data; read_proc_t *read_proc; -- cgit v1.2.1