From 99b76233803beab302123d243eea9e41149804f3 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan <adobriyan@gmail.com> 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 <adobriyan@gmail.com> --- drivers/acpi/button.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'drivers/acpi/button.c') diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c index 171fd914f435..c2f06069dcd4 100644 --- a/drivers/acpi/button.c +++ b/drivers/acpi/button.c @@ -200,12 +200,10 @@ static int acpi_button_add_fs(struct acpi_device *device) if (!entry) return -ENODEV; - entry->owner = THIS_MODULE; acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), entry); if (!acpi_device_dir(device)) return -ENODEV; - acpi_device_dir(device)->owner = THIS_MODULE; /* 'info' [R] */ entry = proc_create_data(ACPI_BUTTON_FILE_INFO, @@ -522,7 +520,6 @@ static int __init acpi_button_init(void) acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir); if (!acpi_button_dir) return -ENODEV; - acpi_button_dir->owner = THIS_MODULE; result = acpi_bus_register_driver(&acpi_button_driver); if (result < 0) { remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir); -- cgit v1.2.2