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 --- arch/x86/kernel/cpu/mtrr/if.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c index 4c4214690dd1..fb73a52913a4 100644 --- a/arch/x86/kernel/cpu/mtrr/if.c +++ b/arch/x86/kernel/cpu/mtrr/if.c @@ -377,10 +377,6 @@ static const struct file_operations mtrr_fops = { .release = mtrr_close, }; - -static struct proc_dir_entry *proc_root_mtrr; - - static int mtrr_seq_show(struct seq_file *seq, void *offset) { char factor; @@ -423,11 +419,7 @@ static int __init mtrr_if_init(void) (!cpu_has(c, X86_FEATURE_CENTAUR_MCR))) return -ENODEV; - proc_root_mtrr = - proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops); - - if (proc_root_mtrr) - proc_root_mtrr->owner = THIS_MODULE; + proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops); return 0; } -- cgit v1.2.2