Hi Arnd,
On 4/30/20 16:30, Arnd Bergmann wrote:
> 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];
> | ^~~~~~~
>
> The structure was already converted to have a flexible-array member in
> the past, but there are two zero-length members in the end and only
> one of them can be a flexible-array member.
>
> Swap the two around to avoid the warning, as 'resp_ids' is not accessed
> in a way that causes a warning.
>
> Fixes: 3ba225b506a2 ("treewide: Replace zero-length array with flexible-array member")
> Fixes: 22e6b3bc5d96 ("ath10k: add new htt definitions")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> drivers/net/wireless/ath/ath10k/htt.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath10k/htt.h b/drivers/net/wireless/ath/ath10k/htt.h
> index e7096a73c6ca..7621f0a3dc77 100644
> --- 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 *
>
The treewide patch is an experimental change and, as this change only applies
to my -next tree, I will carry this patch in it, so other people don't have
to worry about this at all.
Thank you
--
Gustavo
