[PATCH] net_sched: use explicit size of struct tcmsg, remove need to declare tcm

From: Colin Ian King <redacted>

Pointer tcm is being initialized and is never read, it is only being used
to determine the size of struct tcmsg.  Clean this up by removing
variable tcm and explicitly using the sizeof struct tcmsg rather than *tcm.
Cleans up clang warning:

warning: Value stored to 'tcm' during its initialization is never read

Signed-off-by: Colin Ian King <redacted>
---
 net/sched/sch_api.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index c6deb74e3d2f..aa82116ed10c 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c

@@ -1500,7 +1500,6 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
 	int s_idx, s_q_idx;
 	struct net_device *dev;
 	const struct nlmsghdr *nlh = cb->nlh;
-	struct tcmsg *tcm = nlmsg_data(nlh);
 	struct nlattr *tca[TCA_MAX + 1];
 	int err;
 

@@ -1510,7 +1509,7 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
 	idx = 0;
 	ASSERT_RTNL();
 
-	err = nlmsg_parse(nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL);
+	err = nlmsg_parse(nlh, sizeof(struct tcmsg), tca, TCA_MAX, NULL, NULL);
 	if (err < 0)
 		return err;
 

-- 
2.14.1

From: Colin King

Would sizeof(*nlmsg_data(nlh)) be cleaner??

	David

On Mon, 2017-09-18 at 12:18 +0000, David Laight wrote:

From: Colin King

quoted

Sent: 18 September 2017 12:41
Pointer tcm is being initialized and is never read, it is only being used
to determine the size of struct tcmsg.  Clean this up by removing
variable tcm and explicitly using the sizeof struct tcmsg rather than *tcm.
Cleans up clang warning:

warning: Value stored to 'tcm' during its initialization is never read

Signed-off-by: Colin Ian King <redacted>
---
 net/sched/sch_api.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index c6deb74e3d2f..aa82116ed10c 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c

@@ -1500,7 +1500,6 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
 	int s_idx, s_q_idx;
 	struct net_device *dev;
 	const struct nlmsghdr *nlh = cb->nlh;
-	struct tcmsg *tcm = nlmsg_data(nlh);
 	struct nlattr *tca[TCA_MAX + 1];
 	int err;

@@ -1510,7 +1509,7 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
 	idx = 0;
 	ASSERT_RTNL();

-	err = nlmsg_parse(nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL);
+	err = nlmsg_parse(nlh, sizeof(struct tcmsg), tca, TCA_MAX, NULL, NULL);

Would sizeof(*nlmsg_data(nlh)) be cleaner??

Not really, since 

static inline void *nlmsg_data(const struct nlmsghdr *nlh)
{
...
}

From: Eric Dumazet

Sent: 18 September 2017 16:01

...

quoted

quoted

-	err = nlmsg_parse(nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL);
+	err = nlmsg_parse(nlh, sizeof(struct tcmsg), tca, TCA_MAX, NULL, NULL);

Would sizeof(*nlmsg_data(nlh)) be cleaner??

Not really, since

static inline void *nlmsg_data(const struct nlmsghdr *nlh)

I thought about that after posting :-(

	David

From: Colin King <redacted>
Date: Mon, 18 Sep 2017 12:40:38 +0100

From: Colin Ian King <redacted>

Pointer tcm is being initialized and is never read, it is only being used
to determine the size of struct tcmsg.  Clean this up by removing
variable tcm and explicitly using the sizeof struct tcmsg rather than *tcm.
Cleans up clang warning:

warning: Value stored to 'tcm' during its initialization is never read

Signed-off-by: Colin Ian King <redacted>

Applied to net-next.