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author | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-25 19:48:06 (GMT) |
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committer | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-30 21:14:44 (GMT) |
commit | 99b76233803beab302123d243eea9e41149804f3 (patch) | |
tree | 398178210fe66845ccd6fa4258ba762a87e023ad /fs/proc/proc_tty.c | |
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 'fs/proc/proc_tty.c')
-rw-r--r-- | fs/proc/proc_tty.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/fs/proc/proc_tty.c b/fs/proc/proc_tty.c index d153946..4a9e0f6 100644 --- a/fs/proc/proc_tty.c +++ b/fs/proc/proc_tty.c @@ -152,7 +152,6 @@ void proc_tty_register_driver(struct tty_driver *driver) if (!ent) return; ent->read_proc = driver->ops->read_proc; - ent->owner = driver->owner; ent->data = driver; driver->proc_entry = ent; |