ath10k: fix gcc-10 zero-length-bounds warnings

gcc-10 started warning about out-of-bounds access for zero-length
arrays:

In file included from drivers/net/wireless/ath/ath10k/core.h:18,
                 from drivers/net/wireless/ath/ath10k/htt_rx.c:8:
drivers/net/wireless/ath/ath10k/htt_rx.c: In function 'ath10k_htt_rx_tx_fetch_ind':
drivers/net/wireless/ath/ath10k/htt.h:1683:17: warning: array subscript 65535 is outside the bounds of an interior zero-length array 'struct htt_tx_fetch_record[0]' [-Wzero-length-bounds]
 1683 |  return (void *)&ind->records[le16_to_cpu(ind->num_records)];
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/wireless/ath/ath10k/htt.h:1676:29: note: while referencing 'records'
 1676 |  struct htt_tx_fetch_record records[0];
      |                             ^~~~~~~

Make records[] a flexible array member to allow this, moving it behind
the other zero-length member that is not accessed in a way that gcc
warns about.

Fixes: 22e6b3bc5d96 ("ath10k: add new htt definitions")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200509120707.188595-1-arnd@arndb.de

diff --git a/drivers/net/wireless/ath/ath10k/htt.h b/drivers/net/wireless/ath/ath10k/htt.h
index e504be6..cad5949 100644 (file)
--- a/drivers/net/wireless/ath/ath10k/htt.h
+++ b/drivers/net/wireless/ath/ath10k/htt.h
@@ -1673,8 +1673,8 @@ struct htt_tx_fetch_ind {
        __le32 token;
        __le16 num_resp_ids;
        __le16 num_records;
-       struct htt_tx_fetch_record records[0];
-       __le32 resp_ids[]; /* ath10k_htt_get_tx_fetch_ind_resp_ids() */
+       __le32 resp_ids[0]; /* ath10k_htt_get_tx_fetch_ind_resp_ids() */
+       struct htt_tx_fetch_record records[];
 } __packed;
 
 static inline void *