2018-02-20 22:09:32

by Arnd Bergmann

Subject: [PATCH] bpf: clean up unused-variable warning

The only user of this variable is inside of an #ifdef, causing
a warning without CONFIG_INET:

net/core/filter.c: In function '____bpf_sock_ops_cb_flags_set':
net/core/filter.c:3382:6: error: unused variable 'val' [-Werror=unused-variable]
int val = argval & BPF_SOCK_OPS_ALL_CB_FLAGS;

This replaces the #ifdef with a nicer IS_ENABLED() check that
makes the code more readable and avoids the warning.

Fixes: b13d88072172 ("bpf: Adds field bpf_sock_ops_cb_flags to tcp_sock")
Signed-off-by: Arnd Bergmann <[email protected]>
---
net/core/filter.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/net/core/filter.c b/net/core/filter.c
index 08ab4c65a998..0c121adbdbaa 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3381,17 +3381,13 @@ BPF_CALL_2(bpf_sock_ops_cb_flags_set, struct bpf_sock_ops_kern *, bpf_sock,
struct sock *sk = bpf_sock->sk;
int val = argval & BPF_SOCK_OPS_ALL_CB_FLAGS;

- if (!sk_fullsock(sk))
+ if (!IS_ENABLED(CONFIG_INET) || !sk_fullsock(sk))
return -EINVAL;

-#ifdef CONFIG_INET
if (val)
tcp_sk(sk)->bpf_sock_ops_cb_flags = val;

return argval & (~BPF_SOCK_OPS_ALL_CB_FLAGS);
-#else
- return -EINVAL;
-#endif
}

static const struct bpf_func_proto bpf_sock_ops_cb_flags_set_proto = {
--
2.9.0

2018-02-22 00:14:00

by Daniel Borkmann

Subject: Re: [PATCH] bpf: clean up unused-variable warning

On 02/20/2018 11:07 PM, Arnd Bergmann wrote:
> The only user of this variable is inside of an #ifdef, causing
> a warning without CONFIG_INET:
>
> net/core/filter.c: In function '____bpf_sock_ops_cb_flags_set':
> net/core/filter.c:3382:6: error: unused variable 'val' [-Werror=unused-variable]
> int val = argval & BPF_SOCK_OPS_ALL_CB_FLAGS;
>
> This replaces the #ifdef with a nicer IS_ENABLED() check that
> makes the code more readable and avoids the warning.
>
> Fixes: b13d88072172 ("bpf: Adds field bpf_sock_ops_cb_flags to tcp_sock")
> Signed-off-by: Arnd Bergmann <[email protected]>

Now applied to bpf, thanks Arnd!