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 <[email protected]>
---
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 *
--
2.26.0
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 <[email protected]>
> ---
> 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
On Thu, Apr 30, 2020 at 11:41 PM Gustavo A. R. Silva
<[email protected]> wrote:
> On 4/30/20 16:30, Arnd Bergmann wrote:
> > gcc-10 started warning about out-of-bounds access for zero-length
> > arrays:
> 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.
Ok, thanks!
Arnd
On 5/4/20 06:54, Kalle Valo wrote:
> "Gustavo A. R. Silva" <[email protected]> writes:
>
>> 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 <[email protected]>
>>> ---
>>> 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.
>
> Gustavo, why do you have ath10k patches in your tree? I prefer that
> ath10k patches go through my ath.git tree so that they are reviewed and
> tested.
>
I just wanted to test out a mechanical change. I will remove it from my tree
now and will send a patch to you so you can apply it to your ath.git tree.
Thanks!
--
Gustavo