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

From: Minfei Huang
Date: Mon Jul 13 2015 - 23:11:25 EST


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))
--
2.2.2

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