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 --- sound/core/info.c | 31 ++----------------------------- 1 file changed, 2 insertions(+), 29 deletions(-) (limited to 'sound/core') diff --git a/sound/core/info.c b/sound/core/info.c index 70fa87189f36..35df614f6c55 100644 --- a/sound/core/info.c +++ b/sound/core/info.c @@ -154,11 +154,6 @@ EXPORT_SYMBOL(snd_seq_root); struct snd_info_entry *snd_oss_root; #endif -static inline void snd_info_entry_prepare(struct proc_dir_entry *de) -{ - de->owner = THIS_MODULE; -} - static void snd_remove_proc_entry(struct proc_dir_entry *parent, struct proc_dir_entry *de) { @@ -522,32 +517,11 @@ static const struct file_operations snd_info_entry_operations = .release = snd_info_entry_release, }; -/** - * snd_create_proc_entry - create a procfs entry - * @name: the name of the proc file - * @mode: the file permission bits, S_Ixxx - * @parent: the parent proc-directory entry - * - * Creates a new proc file entry with the given name and permission - * on the given directory. - * - * Returns the pointer of new instance or NULL on failure. - */ -static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode, - struct proc_dir_entry *parent) -{ - struct proc_dir_entry *p; - p = create_proc_entry(name, mode, parent); - if (p) - snd_info_entry_prepare(p); - return p; -} - int __init snd_info_init(void) { struct proc_dir_entry *p; - p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, NULL); + p = create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, NULL); if (p == NULL) return -ENOMEM; snd_proc_root = p; @@ -974,12 +948,11 @@ int snd_info_register(struct snd_info_entry * entry) return -ENXIO; root = entry->parent == NULL ? snd_proc_root : entry->parent->p; mutex_lock(&info_mutex); - p = snd_create_proc_entry(entry->name, entry->mode, root); + p = create_proc_entry(entry->name, entry->mode, root); if (!p) { mutex_unlock(&info_mutex); return -ENOMEM; } - p->owner = entry->module; if (!S_ISDIR(entry->mode)) p->proc_fops = &snd_info_entry_operations; p->size = entry->size; -- cgit v1.2.3