diff options
author | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-25 22:48:06 +0300 |
---|---|---|
committer | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-31 01:14:44 +0400 |
commit | 99b76233803beab302123d243eea9e41149804f3 (patch) | |
tree | 398178210fe66845ccd6fa4258ba762a87e023ad /drivers/net/bonding | |
parent | 3dec7f59c370c7b58184d63293c3dc984d475840 (diff) | |
download | linux-99b76233803beab302123d243eea9e41149804f3.tar.xz |
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>
Diffstat (limited to 'drivers/net/bonding')
-rw-r--r-- | drivers/net/bonding/bond_main.c | 35 |
1 files changed, 2 insertions, 33 deletions
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 9c326a50a3ee..99610f358c40 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -3444,25 +3444,12 @@ static void bond_remove_proc_entry(struct bonding *bond) */ static void bond_create_proc_dir(void) { - int len = strlen(DRV_NAME); - - for (bond_proc_dir = init_net.proc_net->subdir; bond_proc_dir; - bond_proc_dir = bond_proc_dir->next) { - if ((bond_proc_dir->namelen == len) && - !memcmp(bond_proc_dir->name, DRV_NAME, len)) { - break; - } - } - if (!bond_proc_dir) { bond_proc_dir = proc_mkdir(DRV_NAME, init_net.proc_net); - if (bond_proc_dir) { - bond_proc_dir->owner = THIS_MODULE; - } else { + if (!bond_proc_dir) printk(KERN_WARNING DRV_NAME ": Warning: cannot create /proc/net/%s\n", DRV_NAME); - } } } @@ -3471,25 +3458,7 @@ static void bond_create_proc_dir(void) */ static void bond_destroy_proc_dir(void) { - struct proc_dir_entry *de; - - if (!bond_proc_dir) { - return; - } - - /* verify that the /proc dir is empty */ - for (de = bond_proc_dir->subdir; de; de = de->next) { - /* ignore . and .. */ - if (*(de->name) != '.') { - break; - } - } - - if (de) { - if (bond_proc_dir->owner == THIS_MODULE) { - bond_proc_dir->owner = NULL; - } - } else { + if (bond_proc_dir) { remove_proc_entry(DRV_NAME, init_net.proc_net); bond_proc_dir = NULL; } |