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 --- drivers/net/bonding/bond_main.c | 35 ++--------------------------------- drivers/net/irda/vlsi_ir.c | 7 ------- drivers/net/wireless/airo.c | 1 - 3 files changed, 2 insertions(+), 41 deletions(-) (limited to 'drivers/net') diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 9c326a50a3e..99610f358c4 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -3444,25 +3444,12 @@ static void bond_remove_proc_entry(struct bonding *bond) */ static void bond_create_proc_dir(void) { - int len = strlen(DRV_NAME); - - for (bond_proc_dir = init_net.proc_net->subdir; bond_proc_dir; - bond_proc_dir = bond_proc_dir->next) { - if ((bond_proc_dir->namelen == len) && - !memcmp(bond_proc_dir->name, DRV_NAME, len)) { - break; - } - } - if (!bond_proc_dir) { bond_proc_dir = proc_mkdir(DRV_NAME, init_net.proc_net); - if (bond_proc_dir) { - bond_proc_dir->owner = THIS_MODULE; - } else { + if (!bond_proc_dir) printk(KERN_WARNING DRV_NAME ": Warning: cannot create /proc/net/%s\n", DRV_NAME); - } } } @@ -3471,25 +3458,7 @@ static void bond_create_proc_dir(void) */ static void bond_destroy_proc_dir(void) { - struct proc_dir_entry *de; - - if (!bond_proc_dir) { - return; - } - - /* verify that the /proc dir is empty */ - for (de = bond_proc_dir->subdir; de; de = de->next) { - /* ignore . and .. */ - if (*(de->name) != '.') { - break; - } - } - - if (de) { - if (bond_proc_dir->owner == THIS_MODULE) { - bond_proc_dir->owner = NULL; - } - } else { + if (bond_proc_dir) { remove_proc_entry(DRV_NAME, init_net.proc_net); bond_proc_dir = NULL; } diff --git a/drivers/net/irda/vlsi_ir.c b/drivers/net/irda/vlsi_ir.c index 1243bc8e003..ac0e4b6b6b6 100644 --- a/drivers/net/irda/vlsi_ir.c +++ b/drivers/net/irda/vlsi_ir.c @@ -1871,13 +1871,6 @@ static int __init vlsi_mod_init(void) * without procfs - it's not required for the driver to work. */ vlsi_proc_root = proc_mkdir(PROC_DIR, NULL); - if (vlsi_proc_root) { - /* protect registered procdir against module removal. - * Because we are in the module init path there's no race - * window after create_proc_entry (and no barrier needed). - */ - vlsi_proc_root->owner = THIS_MODULE; - } ret = pci_register_driver(&vlsi_irda_driver); diff --git a/drivers/net/wireless/airo.c b/drivers/net/wireless/airo.c index 7e80aba8a14..31b1cc2b778 100644 --- a/drivers/net/wireless/airo.c +++ b/drivers/net/wireless/airo.c @@ -4494,7 +4494,6 @@ static int setup_proc_entry( struct net_device *dev, goto fail; apriv->proc_entry->uid = proc_uid; apriv->proc_entry->gid = proc_gid; - apriv->proc_entry->owner = THIS_MODULE; /* Setup the StatsDelta */ entry = proc_create_data("StatsDelta", -- cgit v1.2.3-18-g5258