From: Julia Lawall <[email protected]> This code is not executed before file has been initialized to the result of calling eventfd_fget. This function returns an ERR_PTR value in an error case instead of NULL. Thus the test that file is not NULL is always true.
A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @match exists@ expression x, E; statement S1, S2; @@ x = eventfd_fget(...) ... when != x = E ( * if (x == NULL || ...) S1 else S2 | * if (x == NULL && ...) S1 else S2 ) // </smpl> Signed-off-by: Julia Lawall <[email protected]> Signed-off-by: Avi Kivity <[email protected]> diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index 95954ad..30f70fd 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -228,7 +228,7 @@ fail: if (eventfd && !IS_ERR(eventfd)) eventfd_ctx_put(eventfd); - if (file && !IS_ERR(file)) + if (!IS_ERR(file)) fput(file); kfree(irqfd); -- To unsubscribe from this list: send the line "unsubscribe kvm-commits" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
