Merge branch 'sctp-nested-flex-arrays'

Xin Long says:

====================
sctp: fix a plenty of flexible-array-nested warnings

Paolo noticed a compile warning in SCTP,

../net/sctp/stream_sched_fc.c: note: in included file (through ../include/net/sctp/sctp.h):
../include/net/sctp/structs.h:335:41: warning: array of flexible structures

But not only this, there are actually quite a lot of such warnings in
some SCTP structs. This patchset fixes most of warnings by deleting
these nested flexible array members.

After this patchset, there are still some warnings left:

  # make C=2 CF="-Wflexible-array-nested" M=./net/sctp/
  ./include/net/sctp/structs.h:1145:41: warning: nested flexible array
  ./include/uapi/linux/sctp.h:641:34: warning: nested flexible array
  ./include/uapi/linux/sctp.h:643:34: warning: nested flexible array
  ./include/uapi/linux/sctp.h:644:33: warning: nested flexible array
  ./include/uapi/linux/sctp.h:650:40: warning: nested flexible array
  ./include/uapi/linux/sctp.h:653:39: warning: nested flexible array

the 1st is caused by __data[] in struct ip_options, not in SCTP;
the others are in uapi, and we should not touch them.

Note that instead of completely deleting it, we just leave it as a
comment in the struct, signalling to the reader that we do expect
such variable parameters over there, as Marcelo suggested.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 16 insertions, 16 deletions

diff --git a/include/linux/sctp.h b/include/linux/sctp.h
index 358dc08e0831..836a7e200f39 100644
--- a/include/linux/sctp.h
+++ b/include/linux/sctp.h
@@ -222,7 +222,7 @@ struct sctp_datahdr {
 	__be16 stream;
 	__be16 ssn;
 	__u32 ppid;
-	__u8  payload[];
+	/* __u8  payload[]; */
 };
 
 struct sctp_data_chunk {
@@ -270,7 +270,7 @@ struct sctp_inithdr {
 	__be16 num_outbound_streams;
 	__be16 num_inbound_streams;
 	__be32 initial_tsn;
-	__u8  params[];
+	/* __u8  params[]; */
 };
 
 struct sctp_init_chunk {
@@ -385,7 +385,7 @@ struct sctp_sackhdr {
 	__be32 a_rwnd;
 	__be16 num_gap_ack_blocks;
 	__be16 num_dup_tsns;
-	union sctp_sack_variable variable[];
+	/* union sctp_sack_variable variable[]; */
 };
 
 struct sctp_sack_chunk {
@@ -443,7 +443,7 @@ struct sctp_shutdown_chunk {
 struct sctp_errhdr {
 	__be16 cause;
 	__be16 length;
-	__u8  variable[];
+	/* __u8  variable[]; */
 };
 
 struct sctp_operr_chunk {
@@ -603,7 +603,7 @@ struct sctp_fwdtsn_skip {
 
 struct sctp_fwdtsn_hdr {
 	__be32 new_cum_tsn;
-	struct sctp_fwdtsn_skip skip[];
+	/* struct sctp_fwdtsn_skip skip[]; */
 };
 
 struct sctp_fwdtsn_chunk {
@@ -620,7 +620,7 @@ struct sctp_ifwdtsn_skip {
 
 struct sctp_ifwdtsn_hdr {
 	__be32 new_cum_tsn;
-	struct sctp_ifwdtsn_skip skip[];
+	/* struct sctp_ifwdtsn_skip skip[]; */
 };
 
 struct sctp_ifwdtsn_chunk {
@@ -667,7 +667,7 @@ struct sctp_addip_param {
 
 struct sctp_addiphdr {
 	__be32	serial;
-	__u8	params[];
+	/* __u8	params[]; */
 };
 
 struct sctp_addip_chunk {
@@ -727,7 +727,7 @@ struct sctp_addip_chunk {
 struct sctp_authhdr {
 	__be16 shkey_id;
 	__be16 hmac_id;
-	__u8   hmac[];
+	/* __u8   hmac[]; */
 };
 
 struct sctp_auth_chunk {
@@ -742,7 +742,7 @@ struct sctp_infox {
 
 struct sctp_reconf_chunk {
 	struct sctp_chunkhdr chunk_hdr;
-	__u8 params[];
+	/* __u8 params[]; */
 };
 
 struct sctp_strreset_outreq {
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index c335dd01a597..2a67100b2a17 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -425,11 +425,11 @@ static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
  * the chunk length to indicate when to stop.  Make sure
  * there is room for a param header too.
  */
-#define sctp_walk_params(pos, chunk, member)\
-_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
+#define sctp_walk_params(pos, chunk)\
+_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length))
 
-#define _sctp_walk_params(pos, chunk, end, member)\
-for (pos.v = chunk->member;\
+#define _sctp_walk_params(pos, chunk, end)\
+for (pos.v = (u8 *)(chunk + 1);\
      (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\
       (void *)chunk + end) &&\
      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
@@ -452,8 +452,8 @@ for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \
 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 
 #define _sctp_walk_fwdtsn(pos, chunk, end)\
-for (pos = chunk->subh.fwdtsn_hdr->skip;\
-     (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
+for (pos = (void *)(chunk->subh.fwdtsn_hdr + 1);\
+     (void *)pos <= (void *)(chunk->subh.fwdtsn_hdr + 1) + end - sizeof(struct sctp_fwdtsn_skip);\
      pos++)
 
 /* External references. */
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 070c9458fff4..5c72d1864dd6 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -332,7 +332,7 @@ struct sctp_cookie {
 	 * the association TCB is re-constructed from the cookie.
 	 */
 	__u32 raw_addr_list_len;
-	struct sctp_init_chunk peer_init[];
+	/* struct sctp_init_chunk peer_init[]; */
 };