android_kernel_xiaomi_sm8350/arch/blackfin/mm
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
..
blackfin_sram.h Blackfin arch: change L1 malloc to base on slab cache and lists. 2008-07-19 14:51:31 +08:00
init.c Blackfin arch: mark init_pda as __init as only __init funcs all it 2009-03-05 18:45:07 +08:00
isram-driver.c Blackfin arch: Use DTEST rather than DMA to poke at L1 SRAM during exception context 2008-10-08 18:03:33 +08:00
Makefile Blackfin arch: Use DTEST rather than DMA to poke at L1 SRAM during exception context 2008-10-08 18:03:33 +08:00
sram-alloc.c proc 2/2: remove struct proc_dir_entry::owner 2009-03-31 01:14:44 +04:00