Re: livepatch: separate enabled and patched states

[Jessica Yu]

+++ Josh Poimboeuf [25/03/16 14:34 -0500]:
> Once we have a consistency model, patches and their objects will be
> enabled and disabled at different times.  For example, when a patch is
> disabled, its loaded objects' funcs can remain registered with ftrace
> indefinitely until the unpatching operation is complete and they're no
> longer in use.
>
> It's less confusing if we give them different names: patches can be
> enabled or disabled; objects (and their funcs) can be patched or
> unpatched:
>
> - Enabled means that a patch is logically enabled (but not necessarily
>  fully applied).
>
> - Patched means that an object's funcs are registered with ftrace and
>  added to the klp_ops func stack.
>
> Also, since these states are binary, represent them with booleans
> instead of ints.
>
> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> ---
> include/linux/livepatch.h | 17 ++++-------
> kernel/livepatch/core.c   | 72 +++++++++++++++++++++++------------------------
> 2 files changed, 42 insertions(+), 47 deletions(-)
>
> diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
> index bd830d5..6d45dc7 100644
> --- a/include/linux/livepatch.h
> +++ b/include/linux/livepatch.h
> @@ -28,11 +28,6 @@
>
> #include <asm/livepatch.h>
>
> -enum klp_state {
> -	KLP_DISABLED,
> -	KLP_ENABLED
> -};
> -
> /**
>  * struct klp_func - function structure for live patching
>  * @old_name:	name of the function to be patched
> @@ -41,8 +36,8 @@ enum klp_state {
>  *		can be found (optional)
>  * @old_addr:	the address of the function being patched
>  * @kobj:	kobject for sysfs resources
> - * @state:	tracks function-level patch application state
>  * @stack_node:	list node for klp_ops func_stack list
> + * @patched:	the func has been added to the klp_ops list
>  */
> struct klp_func {
> 	/* external */
> @@ -60,8 +55,8 @@ struct klp_func {
> 	/* internal */
> 	unsigned long old_addr;
> 	struct kobject kobj;
> -	enum klp_state state;
> 	struct list_head stack_node;
> +	bool patched;
> };
>
> /**
> @@ -90,7 +85,7 @@ struct klp_reloc {
>  * @kobj:	kobject for sysfs resources
>  * @mod:	kernel module associated with the patched object
>  * 		(NULL for vmlinux)
> - * @state:	tracks object-level patch application state
> + * @patched:	the object's funcs have been add to the klp_ops list

s/add/added :)