From c23903beefd9eaf1b4572041fbe56c64881f8750 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 14 Apr 2009 12:05:32 -0300 Subject: backport commit 99b76233803beab302123d243eea9e41149804f3 From: Mauro Carvalho Chehab kernel-sync: Author: Alexey Dobriyan Date: Wed Mar 25 22:48:06 2009 +0300 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: Mauro Carvalho Chehab --- linux/drivers/media/video/cpia.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/linux/drivers/media/video/cpia.c b/linux/drivers/media/video/cpia.c index 9baa70fc9..826cf4464 100644 --- a/linux/drivers/media/video/cpia.c +++ b/linux/drivers/media/video/cpia.c @@ -1382,9 +1382,7 @@ static void proc_cpia_create(void) { cpia_proc_root = proc_mkdir("cpia", NULL); - if (cpia_proc_root) - cpia_proc_root->owner = THIS_MODULE; - else + if (!cpia_proc_root) LOG("Unable to initialise /proc/cpia\n"); } -- cgit v1.2.3