livepatch: Don't block the removal of patches loaded after a forced transition
authorPetr Mladek <pmladek@suse.com>
Wed, 9 Jan 2019 12:43:22 +0000 (13:43 +0100)
committerJiri Kosina <jkosina@suse.cz>
Fri, 11 Jan 2019 19:51:24 +0000 (20:51 +0100)
commit68007289bf3cd937a5b8fc4987d2787167bd06ca
tree2c913929da4c5e65fcacdfc5afb47399d86cf446
parent0430f78bf38f9972f0cf0522709cc63d49fa164c
livepatch: Don't block the removal of patches loaded after a forced transition

module_put() is currently never called in klp_complete_transition() when
klp_force is set. As a result, we might keep the reference count even when
klp_enable_patch() fails and klp_cancel_transition() is called.

This might give the impression that a module might get blocked in some
strange init state. Fortunately, it is not the case. The reference count
is ignored when mod->init fails and erroneous modules are always removed.

Anyway, this might be confusing. Instead, this patch moves
the global klp_forced flag into struct klp_patch. As a result,
we block only modules that might still be in use after a forced
transition. Newly loaded livepatches might be eventually completely
removed later.

It is not a big deal. But the code is at least consistent with
the reality.

Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
include/linux/livepatch.h
kernel/livepatch/core.c
kernel/livepatch/core.h
kernel/livepatch/transition.c