Re: [RFC 4/7] selinux: mark __ro_mostly_after_init for selinux_hooks/selinux_nf_ops

From: Tetsuo Handa
Date: Tue Feb 21 2017 - 05:35:48 EST

On 2017/02/19 19:04, Hoeun Ryu wrote:
> It would be good that selinux hooks objects are marked as
> `__ro_mostly_after_init`. They can not be simply marked as `__ro_after_init'
> because they should be writable during selinux_disable procedure.
> `__ro_mostly_after_init` section is temporarily read-write during
> selinux_disable procedure via set_ro_mostly_after_init_rw/ro pair. Now that
> they can be read-only except during the procedure.
> -static struct security_hook_list selinux_hooks[] = {
> +static struct security_hook_list selinux_hooks[] __ro_mostly_after_init = {

This won't work. This variable is array of "struct list_head".
You need to set same attribute to variables pointed by
"struct list_head"->next and "struct list_head"->prev .

> LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
> LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
> LSM_HOOK_INIT(binder_transfer_binder, selinux_binder_transfer_binder),