linux/arch/x86/kernel/cpu/mtrr
Alexey Dobriyan 99b7623380 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>
2009-03-31 01:14:44 +04:00
..
Makefile x86: separate mtrr cleanup/mtrr_e820 trim to separate file 2009-03-13 02:52:19 +01:00
amd.c x86: mtrr use type bool [RESEND AGAIN] 2008-01-30 13:30:31 +01:00
centaur.c
cleanup.c x86: cpu/mttr/cleanup.c fix compilation warning 2009-03-18 13:14:31 +01:00
cyrix.c x86: remove long dead cyrix mtrr code 2008-02-04 16:48:01 +01:00
generic.c x86: print the continous part of fixed mtrrs together 2009-03-14 12:27:06 +01:00
if.c proc 2/2: remove struct proc_dir_entry::owner 2009-03-31 01:14:44 +04:00
main.c x86: MTRR workaround for system with stange var MTRRs 2009-03-17 10:47:47 +01:00
mtrr.h x86: MTRR workaround for system with stange var MTRRs 2009-03-17 10:47:47 +01:00
state.c x86: coding style fixes to arch/x86/kernel/cpu/mtrr/state.c 2008-04-17 17:40:49 +02:00