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 --- net/can/bcm.c | 4 ---- net/can/proc.c | 2 -- 2 files changed, 6 deletions(-) (limited to 'net/can') diff --git a/net/can/bcm.c b/net/can/bcm.c index b7c7d465113..95d7f32643a 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -1604,10 +1604,6 @@ static int __init bcm_module_init(void) /* create /proc/net/can-bcm directory */ proc_dir = proc_mkdir("can-bcm", init_net.proc_net); - - if (proc_dir) - proc_dir->owner = THIS_MODULE; - return 0; } diff --git a/net/can/proc.c b/net/can/proc.c index 520fef5e539..1463653dbe3 100644 --- a/net/can/proc.c +++ b/net/can/proc.c @@ -473,8 +473,6 @@ void can_init_proc(void) return; } - can_dir->owner = THIS_MODULE; - /* own procfs entries from the AF_CAN core */ pde_version = can_create_proc_readentry(CAN_PROC_VERSION, 0644, can_proc_read_version, NULL); -- cgit v1.2.3-70-g09d2