Re: [PATCH] livepatch: klp_disable_func returnes once it does not satisfy the condition

From: Josh Poimboeuf
Date: Mon Jul 13 2015 - 23:51:29 EST


On Tue, Jul 14, 2015 at 11:15:37AM +0800, Minfei Huang wrote:
> From: Minfei Huang <mnfhuang@xxxxxxxxx>
>
> It is more better that klp_disable_func returnes immediately, if
> func->state and func->old_addr do not satisfy the condition.
>
> We should robust the livepatch code, although the above situation never
> happen in current code path.
>
> Signed-off-by: Minfei Huang <mnfhuang@xxxxxxxxx>
> ---
> kernel/livepatch/core.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
> index c40ebcc..6e53441 100644
> --- a/kernel/livepatch/core.c
> +++ b/kernel/livepatch/core.c
> @@ -348,8 +348,10 @@ static void klp_disable_func(struct klp_func *func)
> {
> struct klp_ops *ops;
>
> - WARN_ON(func->state != KLP_ENABLED);
> - WARN_ON(!func->old_addr);
> + if (WARN_ON(func->state != KLP_ENABLED))
> + return;
> + if (WARN_ON(!func->old_addr))
> + return;
>
> ops = klp_find_ops(func->old_addr);
> if (WARN_ON(!ops))

Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
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