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/char/ipmi/ipmi_msghandler.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'drivers/char/ipmi/ipmi_msghandler.c') diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 7a88dfd4427b..e93fc8d22fb2 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -1944,7 +1944,7 @@ static int stat_file_read_proc(char *page, char **start, off_t off, int ipmi_smi_add_proc_entry(ipmi_smi_t smi, char *name, read_proc_t *read_proc, - void *data, struct module *owner) + void *data) { int rv = 0; #ifdef CONFIG_PROC_FS @@ -1970,7 +1970,6 @@ int ipmi_smi_add_proc_entry(ipmi_smi_t smi, char *name, } else { file->data = data; file->read_proc = read_proc; - file->owner = owner; mutex_lock(&smi->proc_entry_lock); /* Stick it on the list. */ @@ -1993,23 +1992,21 @@ static int add_proc_entries(ipmi_smi_t smi, int num) smi->proc_dir = proc_mkdir(smi->proc_dir_name, proc_ipmi_root); if (!smi->proc_dir) rv = -ENOMEM; - else - smi->proc_dir->owner = THIS_MODULE; if (rv == 0) rv = ipmi_smi_add_proc_entry(smi, "stats", stat_file_read_proc, - smi, THIS_MODULE); + smi); if (rv == 0) rv = ipmi_smi_add_proc_entry(smi, "ipmb", ipmb_file_read_proc, - smi, THIS_MODULE); + smi); if (rv == 0) rv = ipmi_smi_add_proc_entry(smi, "version", version_file_read_proc, - smi, THIS_MODULE); + smi); #endif /* CONFIG_PROC_FS */ return rv; @@ -4265,7 +4262,6 @@ static int ipmi_init_msghandler(void) return -ENOMEM; } - proc_ipmi_root->owner = THIS_MODULE; #endif /* CONFIG_PROC_FS */ setup_timer(&ipmi_timer, ipmi_timeout, 0); -- cgit v1.2.3