phonet: fix building with clang

[ Upstream commit 6321aa197547da397753757bd84c6ce64b3e3d89 ]

clang warns about overflowing the data[] member in the struct pnpipehdr:

net/phonet/pep.c:295:8: warning: array index 4 is past the end of the array (which contains 1 element) [-Warray-bounds]
                        if (hdr->data[4] == PEP_IND_READY)
                            ^         ~
include/net/phonet/pep.h:66:3: note: array 'data' declared here
                u8              data[1];

Using a flexible array member at the end of the struct avoids the
warning, but since we cannot have a flexible array member inside
of the union, each index now has to be moved back by one, which
makes it a little uglier.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Rémi Denis-Courmont <remi@remlab.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/include/net/phonet/pep.h b/include/net/phonet/pep.h
index b669fe6dbc3bad2a6d61b7a2b9d54ff83b7e51c8..98f31c7ea23df92e82f00c251bdeca684180b1b5 100644 (file)
--- a/include/net/phonet/pep.h
+++ b/include/net/phonet/pep.h
@@ -63,10 +63,11 @@ struct pnpipehdr {
                u8              state_after_reset;      /* reset request */
                u8              error_code;             /* any response */
                u8              pep_type;               /* status indication */
-               u8              data[1];
+               u8              data0;                  /* anything else */
        };
+       u8                      data[];
 };
-#define other_pep_type         data[1]
+#define other_pep_type         data[0]
 
 static inline struct pnpipehdr *pnp_hdr(struct sk_buff *skb)
 {

diff --git a/net/phonet/pep.c b/net/phonet/pep.c
index 850a86cde0b3f6eab5b7aa09f4e6ffa66ccd6ed6..f6aa532bcbf64737476f9731e5b9f0f20dc6e72c 100644 (file)
--- a/net/phonet/pep.c
+++ b/net/phonet/pep.c
@@ -131,7 +131,7 @@ static int pep_indicate(struct sock *sk, u8 id, u8 code,
        ph->utid = 0;
        ph->message_id = id;
        ph->pipe_handle = pn->pipe_handle;
-       ph->data[0] = code;
+       ph->error_code = code;
        return pn_skb_send(sk, skb, NULL);
 }
 
@@ -152,7 +152,7 @@ static int pipe_handler_request(struct sock *sk, u8 id, u8 code,
        ph->utid = id; /* whatever */
        ph->message_id = id;
        ph->pipe_handle = pn->pipe_handle;
-       ph->data[0] = code;
+       ph->error_code = code;
        return pn_skb_send(sk, skb, NULL);
 }
 
@@ -207,7 +207,7 @@ static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
        struct pnpipehdr *ph;
        struct sockaddr_pn dst;
        u8 data[4] = {
-               oph->data[0], /* PEP type */
+               oph->pep_type, /* PEP type */
                code, /* error code, at an unusual offset */
                PAD, PAD,
        };
@@ -220,7 +220,7 @@ static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
        ph->utid = oph->utid;
        ph->message_id = PNS_PEP_CTRL_RESP;
        ph->pipe_handle = oph->pipe_handle;
-       ph->data[0] = oph->data[1]; /* CTRL id */
+       ph->data0 = oph->data[0]; /* CTRL id */
 
        pn_skb_get_src_sockaddr(oskb, &dst);
        return pn_skb_send(sk, skb, &dst);
@@ -271,17 +271,17 @@ static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
                return -EINVAL;
 
        hdr = pnp_hdr(skb);
-       if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
+       if (hdr->pep_type != PN_PEP_TYPE_COMMON) {
                net_dbg_ratelimited("Phonet unknown PEP type: %u\n",
-                                   (unsigned int)hdr->data[0]);
+                                   (unsigned int)hdr->pep_type);
                return -EOPNOTSUPP;
        }
 
-       switch (hdr->data[1]) {
+       switch (hdr->data[0]) {
        case PN_PEP_IND_FLOW_CONTROL:
                switch (pn->tx_fc) {
                case PN_LEGACY_FLOW_CONTROL:
-                       switch (hdr->data[4]) {
+                       switch (hdr->data[3]) {
                        case PEP_IND_BUSY:
                                atomic_set(&pn->tx_credits, 0);
                                break;
@@ -291,7 +291,7 @@ static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
                        }
                        break;
                case PN_ONE_CREDIT_FLOW_CONTROL:
-                       if (hdr->data[4] == PEP_IND_READY)
+                       if (hdr->data[3] == PEP_IND_READY)
                                atomic_set(&pn->tx_credits, wake = 1);
                        break;
                }
@@ -300,12 +300,12 @@ static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
        case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
                if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
                        break;
-               atomic_add(wake = hdr->data[4], &pn->tx_credits);
+               atomic_add(wake = hdr->data[3], &pn->tx_credits);
                break;
 
        default:
                net_dbg_ratelimited("Phonet unknown PEP indication: %u\n",
-                                   (unsigned int)hdr->data[1]);
+                                   (unsigned int)hdr->data[0]);
                return -EOPNOTSUPP;
        }
        if (wake)
@@ -317,7 +317,7 @@ static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
 {
        struct pep_sock *pn = pep_sk(sk);
        struct pnpipehdr *hdr = pnp_hdr(skb);
-       u8 n_sb = hdr->data[0];
+       u8 n_sb = hdr->data0;
 
        pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
        __skb_pull(skb, sizeof(*hdr));
@@ -505,7 +505,7 @@ static int pep_connresp_rcv(struct sock *sk, struct sk_buff *skb)
                return -ECONNREFUSED;
 
        /* Parse sub-blocks */
-       n_sb = hdr->data[4];
+       n_sb = hdr->data[3];
        while (n_sb > 0) {
                u8 type, buf[6], len = sizeof(buf);
                const u8 *data = pep_get_sb(skb, &type, &len, buf);
@@ -738,7 +738,7 @@ static int pipe_do_remove(struct sock *sk)
        ph->utid = 0;
        ph->message_id = PNS_PIPE_REMOVE_REQ;
        ph->pipe_handle = pn->pipe_handle;
-       ph->data[0] = PAD;
+       ph->data0 = PAD;
        return pn_skb_send(sk, skb, NULL);
 }
 
@@ -815,7 +815,7 @@ static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
        peer_type = hdr->other_pep_type << 8;
 
        /* Parse sub-blocks (options) */
-       n_sb = hdr->data[4];
+       n_sb = hdr->data[3];
        while (n_sb > 0) {
                u8 type, buf[1], len = sizeof(buf);
                const u8 *data = pep_get_sb(skb, &type, &len, buf);
@@ -1106,7 +1106,7 @@ static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
        ph->utid = 0;
        if (pn->aligned) {
                ph->message_id = PNS_PIPE_ALIGNED_DATA;
-               ph->data[0] = 0; /* padding */
+               ph->data0 = 0; /* padding */
        } else
                ph->message_id = PNS_PIPE_DATA;
        ph->pipe_handle = pn->pipe_handle;