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/platform/x86/asus_acpi.c | 3 --- drivers/platform/x86/thinkpad_acpi.c | 2 -- drivers/platform/x86/toshiba_acpi.c | 3 --- 3 files changed, 8 deletions(-) (limited to 'drivers/platform') diff --git a/drivers/platform/x86/asus_acpi.c b/drivers/platform/x86/asus_acpi.c index d63f26e666a..ba1f7497e4b 100644 --- a/drivers/platform/x86/asus_acpi.c +++ b/drivers/platform/x86/asus_acpi.c @@ -987,7 +987,6 @@ asus_proc_add(char *name, proc_writefunc *writefunc, proc->write_proc = writefunc; proc->read_proc = readfunc; proc->data = acpi_driver_data(device); - proc->owner = THIS_MODULE; proc->uid = asus_uid; proc->gid = asus_gid; return 0; @@ -1020,7 +1019,6 @@ static int asus_hotk_add_fs(struct acpi_device *device) if (proc) { proc->read_proc = proc_read_info; proc->data = acpi_driver_data(device); - proc->owner = THIS_MODULE; proc->uid = asus_uid; proc->gid = asus_gid; } else { @@ -1436,7 +1434,6 @@ static int __init asus_acpi_init(void) printk(KERN_ERR "Asus ACPI: Unable to create /proc entry\n"); return -ENODEV; } - asus_proc_dir->owner = THIS_MODULE; result = acpi_bus_register_driver(&asus_hotk_driver); if (result < 0) { diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index d2433204a40..3dad27a385d 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -6992,7 +6992,6 @@ static int __init ibm_init(struct ibm_init_struct *iibm) ret = -ENODEV; goto err_out; } - entry->owner = THIS_MODULE; entry->data = ibm; entry->read_proc = &dispatch_procfs_read; if (ibm->write) @@ -7405,7 +7404,6 @@ static int __init thinkpad_acpi_module_init(void) thinkpad_acpi_module_exit(); return -ENODEV; } - proc_dir->owner = THIS_MODULE; ret = platform_driver_register(&tpacpi_pdriver); if (ret) { diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c index 40e60fc2e59..9f187265db8 100644 --- a/drivers/platform/x86/toshiba_acpi.c +++ b/drivers/platform/x86/toshiba_acpi.c @@ -679,8 +679,6 @@ static acpi_status __init add_device(void) toshiba_proc_dir, (read_proc_t *) dispatch_read, item); - if (proc) - proc->owner = THIS_MODULE; if (proc && item->write_func) proc->write_proc = (write_proc_t *) dispatch_write; } @@ -772,7 +770,6 @@ static int __init toshiba_acpi_init(void) toshiba_acpi_exit(); return -ENODEV; } else { - toshiba_proc_dir->owner = THIS_MODULE; status = add_device(); if (ACPI_FAILURE(status)) { toshiba_acpi_exit(); -- cgit v1.2.3