[PATCH] net: netfilter: fix false positive GCC warnings

From: Dmitry Safonov
Date: Fri Nov 06 2015 - 14:35:03 EST


With x86_64_defconfig:
GCC thinks that in nfulnl_recv_config flags parameter is not inited but
it was under the same condition (nfula[NFULA_CFG_FLAGS] == true).
Suppress this warning:
net/netfilter/nfnetlink_log.c: In function ânfulnl_recv_configâ:
net/netfilter/nfnetlink_log.c:320:14: warning: âflagsâ may be used uninitialized in this function [-Wmaybe-uninitialized]
inst->flags = flags;
^
GCC thinks that nfnl_ct wasn't inited, but it is used only under
if (ct && diff)
where ct is not NULL only when nfnl_ct is inited.

Reported-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Dmitry Safonov <0x7f454c46@xxxxxxxxx>
---
net/netfilter/nfnetlink_log.c | 2 +-
net/netfilter/nfnetlink_queue.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index 06eb48fceb42e4..23f16b99e6388a 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -825,7 +825,7 @@ nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
struct net *net = sock_net(ctnl);
struct nfnl_log_net *log = nfnl_log_pernet(net);
int ret = 0;
- u16 flags;
+ u16 uninitialized_var(flags);

if (nfula[NFULA_CFG_CMD]) {
u_int8_t pf = nfmsg->nfgen_family;
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 7d81d280cb4ff3..66b006112921ca 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -313,7 +313,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
struct net_device *outdev;
struct nf_conn *ct = NULL;
enum ip_conntrack_info uninitialized_var(ctinfo);
- struct nfnl_ct_hook *nfnl_ct;
+ struct nfnl_ct_hook *uninitialized_var(nfnl_ct);
bool csum_verify;
char *secdata = NULL;
u32 seclen = 0;
@@ -1041,7 +1041,7 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
unsigned int verdict;
struct nf_queue_entry *entry;
enum ip_conntrack_info uninitialized_var(ctinfo);
- struct nfnl_ct_hook *nfnl_ct;
+ struct nfnl_ct_hook *uninitialized_var(nfnl_ct);
struct nf_conn *ct = NULL;

struct net *net = sock_net(ctnl);
--
2.6.2

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