[PATCH] bpfilter: fix building without CONFIG_INET

[PATCH] bpfilter: fix building without CONFIG_INET

[Arnd Bergmann]

bpfilter_process_sockopt is a callback that gets called from
ip_setsockopt() and ip_getsockopt(). However, when CONFIG_INET is
disabled, it never gets called at all, and assigning a function to the
callback pointer results in a link failure:

net/bpfilter/bpfilter_kern.o: In function `__stop_umh':
bpfilter_kern.c:(.text.unlikely+0x3): undefined reference to `bpfilter_process_sockopt'
net/bpfilter/bpfilter_kern.o: In function `load_umh':
bpfilter_kern.c:(.init.text+0x73): undefined reference to `bpfilter_process_sockopt'

Since there is no caller in this configuration, I assume we can
simply make the assignment conditional.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
This happened on last week's linux-next tree. Since there hasn't
been an update since, it's possible that this is fixed in another
tree already.
---
 net/bpfilter/bpfilter_kern.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c
index 7596314b61c7..b13d058f8c34 100644
--- a/net/bpfilter/bpfilter_kern.c
+++ b/net/bpfilter/bpfilter_kern.c
@@ -33,7 +33,8 @@ static void shutdown_umh(struct umh_info *info)
 
 static void __stop_umh(void)
 {
-	if (bpfilter_process_sockopt) {
+	if (IS_ENABLED(CONFIG_INET) &&
+	    bpfilter_process_sockopt) {
 		bpfilter_process_sockopt = NULL;
 		shutdown_umh(&info);
 	}
@@ -98,7 +99,9 @@ static int __init load_umh(void)
 		stop_umh();
 		return -EFAULT;
 	}
-	bpfilter_process_sockopt = &__bpfilter_process_sockopt;
+	if (IS_ENABLED(CONFIG_INET))
+		bpfilter_process_sockopt = &__bpfilter_process_sockopt;
+
 	return 0;
 }
 
-- 
2.9.0

Re: [PATCH] bpfilter: fix building without CONFIG_INET

[David Miller]

From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 29 May 2018 11:55:06 +0200

> bpfilter_process_sockopt is a callback that gets called from
> ip_setsockopt() and ip_getsockopt(). However, when CONFIG_INET is
> disabled, it never gets called at all, and assigning a function to the
> callback pointer results in a link failure:
> 
> net/bpfilter/bpfilter_kern.o: In function `__stop_umh':
> bpfilter_kern.c:(.text.unlikely+0x3): undefined reference to `bpfilter_process_sockopt'
> net/bpfilter/bpfilter_kern.o: In function `load_umh':
> bpfilter_kern.c:(.init.text+0x73): undefined reference to `bpfilter_process_sockopt'
> 
> Since there is no caller in this configuration, I assume we can
> simply make the assignment conditional.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Applied, thanks Arnd.