[PATCH net-next 0/3] compiler_types: add Endianness-dependent __counted_by_{le,be}

[PATCH net-next 0/3] compiler_types: add Endianness-dependent __counted_by_{le,be}

[Alexander Lobakin]

Some structures contain flexible arrays at the end and the counter for
them, but the counter has explicit Endianness and thus __counted_by()
can't be used directly.

To increase test coverage for potential problems without breaking
anything, introduce __counted_by_{le,be} defined depending on platform's
Endianness to either __counted_by() when applicable or noop otherwise.
The first user will be virtchnl2.h from idpf just as example with 9 flex
structures having Little Endian counters.

Maybe it would be a good idea to introduce such attributes on compiler
level if possible, but for now let's stop on what we have.

Alexander Lobakin (3):
  compiler_types: add Endianness-dependent __counted_by_{le,be}
  idpf: make virtchnl2.h self-contained
  idpf: sprinkle __counted_by{,_le}() in the virtchnl2 header

 Documentation/conf.py                       |  2 ++
 scripts/kernel-doc                          |  1 +
 include/linux/compiler_types.h              | 11 ++++++++++
 drivers/net/ethernet/intel/idpf/virtchnl2.h | 24 ++++++++++-----------
 4 files changed, 26 insertions(+), 12 deletions(-)

---
From RFC[0]:

* teach kdoc new attributes (Simon, Kees);
* add Acked-by (Kees);
* fix a couple typos;
* send to net-next (Kees).

[0] https://lore.kernel.org/netdev/20240318130354.2713265-1-aleksander.lobakin@intel.com
-- 
2.44.0

[PATCH net-next 1/3] compiler_types: add Endianness-dependent __counted_by_{le,be}

[Alexander Lobakin]

Some structures contain flexible arrays at the end and the counter for
them, but the counter has explicit Endianness and thus __counted_by()
can't be used directly.

To increase test coverage for potential problems without breaking
anything, introduce __counted_by_{le,be}() defined depending on
platform's Endianness to either __counted_by() when applicable or noop
otherwise.
Maybe it would be a good idea to introduce such attributes on compiler
level if possible, but for now let's stop on what we have.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
 Documentation/conf.py          |  2 ++
 scripts/kernel-doc             |  1 +
 include/linux/compiler_types.h | 11 +++++++++++
 3 files changed, 14 insertions(+)

diff --git a/Documentation/conf.py b/Documentation/conf.py
index d148f3e8dd57..0c2205d536b3 100644
--- a/Documentation/conf.py
+++ b/Documentation/conf.py
@@ -75,6 +75,8 @@ if major >= 3:
             "__rcu",
             "__user",
             "__force",
+            "__counted_by_le",
+            "__counted_by_be",
 
             # include/linux/compiler_attributes.h:
             "__alias",
diff --git a/scripts/kernel-doc b/scripts/kernel-doc
index 967f1abb0edb..1474e95dbe4f 100755
--- a/scripts/kernel-doc
+++ b/scripts/kernel-doc
@@ -1143,6 +1143,7 @@ sub dump_struct($$) {
         $members =~ s/\s*$attribute/ /gi;
         $members =~ s/\s*__aligned\s*\([^;]*\)/ /gos;
         $members =~ s/\s*__counted_by\s*\([^;]*\)/ /gos;
+        $members =~ s/\s*__counted_by_(le|be)\s*\([^;]*\)/ /gos;
         $members =~ s/\s*__packed\s*/ /gos;
         $members =~ s/\s*CRYPTO_MINALIGN_ATTR/ /gos;
         $members =~ s/\s*____cacheline_aligned_in_smp/ /gos;
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 2abaa3a825a9..a29ba6ef1e27 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -282,6 +282,17 @@ struct ftrace_likely_data {
 #define __no_sanitize_or_inline __always_inline
 #endif
 
+/*
+ * Apply __counted_by() when the Endianness matches to increase test coverage.
+ */
+#ifdef __LITTLE_ENDIAN
+#define __counted_by_le(member)	__counted_by(member)
+#define __counted_by_be(member)
+#else
+#define __counted_by_le(member)
+#define __counted_by_be(member)	__counted_by(member)
+#endif
+
 /* Do not trap wrapping arithmetic within an annotated function. */
 #ifdef CONFIG_UBSAN_SIGNED_WRAP
 # define __signed_wrap __attribute__((no_sanitize("signed-integer-overflow")))
-- 
2.44.0

Re: [PATCH net-next 1/3] compiler_types: add Endianness-dependent __counted_by_{le,be}

[Gustavo A. R. Silva]

On 3/26/24 10:41, Alexander Lobakin wrote:
> Some structures contain flexible arrays at the end and the counter for
> them, but the counter has explicit Endianness and thus __counted_by()
> can't be used directly.
> 
> To increase test coverage for potential problems without breaking
> anything, introduce __counted_by_{le,be}() defined depending on
> platform's Endianness to either __counted_by() when applicable or noop
> otherwise.
> Maybe it would be a good idea to introduce such attributes on compiler
> level if possible, but for now let's stop on what we have.
> 
> Acked-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>

LGTM:

Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks
--
Gustavo

> ---
>   Documentation/conf.py          |  2 ++
>   scripts/kernel-doc             |  1 +
>   include/linux/compiler_types.h | 11 +++++++++++
>   3 files changed, 14 insertions(+)
> 
> diff --git a/Documentation/conf.py b/Documentation/conf.py
> index d148f3e8dd57..0c2205d536b3 100644
> --- a/Documentation/conf.py
> +++ b/Documentation/conf.py
> @@ -75,6 +75,8 @@ if major >= 3:
>               "__rcu",
>               "__user",
>               "__force",
> +            "__counted_by_le",
> +            "__counted_by_be",
>   
>               # include/linux/compiler_attributes.h:
>               "__alias",
> diff --git a/scripts/kernel-doc b/scripts/kernel-doc
> index 967f1abb0edb..1474e95dbe4f 100755
> --- a/scripts/kernel-doc
> +++ b/scripts/kernel-doc
> @@ -1143,6 +1143,7 @@ sub dump_struct($$) {
>           $members =~ s/\s*$attribute/ /gi;
>           $members =~ s/\s*__aligned\s*\([^;]*\)/ /gos;
>           $members =~ s/\s*__counted_by\s*\([^;]*\)/ /gos;
> +        $members =~ s/\s*__counted_by_(le|be)\s*\([^;]*\)/ /gos;
>           $members =~ s/\s*__packed\s*/ /gos;
>           $members =~ s/\s*CRYPTO_MINALIGN_ATTR/ /gos;
>           $members =~ s/\s*____cacheline_aligned_in_smp/ /gos;
> diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
> index 2abaa3a825a9..a29ba6ef1e27 100644
> --- a/include/linux/compiler_types.h
> +++ b/include/linux/compiler_types.h
> @@ -282,6 +282,17 @@ struct ftrace_likely_data {
>   #define __no_sanitize_or_inline __always_inline
>   #endif
>   
> +/*
> + * Apply __counted_by() when the Endianness matches to increase test coverage.
> + */
> +#ifdef __LITTLE_ENDIAN
> +#define __counted_by_le(member)	__counted_by(member)
> +#define __counted_by_be(member)
> +#else
> +#define __counted_by_le(member)
> +#define __counted_by_be(member)	__counted_by(member)
> +#endif
> +
>   /* Do not trap wrapping arithmetic within an annotated function. */
>   #ifdef CONFIG_UBSAN_SIGNED_WRAP
>   # define __signed_wrap __attribute__((no_sanitize("signed-integer-overflow")))

[PATCH net-next 2/3] idpf: make virtchnl2.h self-contained

[Alexander Lobakin]

To ease maintaining of virtchnl2.h, which already is messy enough,
make it self-contained by adding missing if_ether.h include due to
%ETH_ALEN usage.
At the same time, virtchnl2_lan_desc.h is not used anywhere in the
file, so remove this include to speed up C preprocessing.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
 drivers/net/ethernet/intel/idpf/virtchnl2.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/idpf/virtchnl2.h b/drivers/net/ethernet/intel/idpf/virtchnl2.h
index 4a3c4454d25a..29419211b3d9 100644
--- a/drivers/net/ethernet/intel/idpf/virtchnl2.h
+++ b/drivers/net/ethernet/intel/idpf/virtchnl2.h
@@ -4,6 +4,8 @@
 #ifndef _VIRTCHNL2_H_
 #define _VIRTCHNL2_H_
 
+#include <linux/if_ether.h>
+
 /* All opcodes associated with virtchnl2 are prefixed with virtchnl2 or
  * VIRTCHNL2. Any future opcodes, offloads/capabilities, structures,
  * and defines must be prefixed with virtchnl2 or VIRTCHNL2 to avoid confusion.
@@ -17,8 +19,6 @@
  * must remain unchanged over time, so we specify explicit values for all enums.
  */
 
-#include "virtchnl2_lan_desc.h"
-
 /* This macro is used to generate compilation errors if a structure
  * is not exactly the correct length.
  */
-- 
2.44.0

Re: [PATCH net-next 2/3] idpf: make virtchnl2.h self-contained

[Gustavo A. R. Silva]

On 3/26/24 10:41, Alexander Lobakin wrote:
> To ease maintaining of virtchnl2.h, which already is messy enough,
> make it self-contained by adding missing if_ether.h include due to
> %ETH_ALEN usage.
> At the same time, virtchnl2_lan_desc.h is not used anywhere in the
> file, so remove this include to speed up C preprocessing.
> 
> Acked-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>

Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks
-- 
Gustavo

> ---
>   drivers/net/ethernet/intel/idpf/virtchnl2.h | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/idpf/virtchnl2.h b/drivers/net/ethernet/intel/idpf/virtchnl2.h
> index 4a3c4454d25a..29419211b3d9 100644
> --- a/drivers/net/ethernet/intel/idpf/virtchnl2.h
> +++ b/drivers/net/ethernet/intel/idpf/virtchnl2.h
> @@ -4,6 +4,8 @@
>   #ifndef _VIRTCHNL2_H_
>   #define _VIRTCHNL2_H_
>   
> +#include <linux/if_ether.h>
> +
>   /* All opcodes associated with virtchnl2 are prefixed with virtchnl2 or
>    * VIRTCHNL2. Any future opcodes, offloads/capabilities, structures,
>    * and defines must be prefixed with virtchnl2 or VIRTCHNL2 to avoid confusion.
> @@ -17,8 +19,6 @@
>    * must remain unchanged over time, so we specify explicit values for all enums.
>    */
>   
> -#include "virtchnl2_lan_desc.h"
> -
>   /* This macro is used to generate compilation errors if a structure
>    * is not exactly the correct length.
>    */

Re: [PATCH net-next 2/3] idpf: make virtchnl2.h self-contained

[Jakub Kicinski]

On Tue, 26 Mar 2024 17:41:15 +0100 Alexander Lobakin wrote:
> To ease maintaining of virtchnl2.h, which already is messy enough,
> make it self-contained by adding missing if_ether.h include due to
> %ETH_ALEN usage.
> At the same time, virtchnl2_lan_desc.h is not used anywhere in the
> file, so remove this include to speed up C preprocessing.

Breaks allmodconfig, it seems..
-- 
pw-bot: cr

Re: [Intel-wired-lan] [PATCH net-next 2/3] idpf: make virtchnl2.h self-contained

[Alexander Lobakin]

From: Jakub Kicinski <kuba@kernel.org>
Date: Tue, 26 Mar 2024 21:04:12 -0700

> On Tue, 26 Mar 2024 17:41:15 +0100 Alexander Lobakin wrote:
>> To ease maintaining of virtchnl2.h, which already is messy enough,
>> make it self-contained by adding missing if_ether.h include due to
>> %ETH_ALEN usage.
>> At the same time, virtchnl2_lan_desc.h is not used anywhere in the
>> file, so remove this include to speed up C preprocessing.
> 
> Breaks allmodconfig, it seems..

Oops, forgot one line and my night CI didn't notice anything...
Sending v2.

Thanks,
Olek

[PATCH net-next 3/3] idpf: sprinkle __counted_by{,_le}() in the virtchnl2 header

[Alexander Lobakin]

Both virtchnl2.h and its consumer idpf_virtchnl.c are very error-prone.
There are 10 structures with flexible arrays at the end, but 9 of them
has flex member counter in Little Endian.
Make the code a bit more robust by applying __counted_by_le() to those
9. LE platforms is the main target for this driver, so they would
receive additional protection.
While we're here, add __counted_by() to virtchnl2_ptype::proto_id, as
its counter is `u8` regardless of the Endianness.
Compile test on x86_64 (LE) didn't reveal any new issues after applying
the attributes.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
 drivers/net/ethernet/intel/idpf/virtchnl2.h | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/intel/idpf/virtchnl2.h b/drivers/net/ethernet/intel/idpf/virtchnl2.h
index 29419211b3d9..63deb120359c 100644
--- a/drivers/net/ethernet/intel/idpf/virtchnl2.h
+++ b/drivers/net/ethernet/intel/idpf/virtchnl2.h
@@ -555,7 +555,7 @@ VIRTCHNL2_CHECK_STRUCT_LEN(32, virtchnl2_queue_reg_chunk);
 struct virtchnl2_queue_reg_chunks {
 	__le16 num_chunks;
 	u8 pad[6];
-	struct virtchnl2_queue_reg_chunk chunks[];
+	struct virtchnl2_queue_reg_chunk chunks[] __counted_by_le(num_chunks);
 };
 VIRTCHNL2_CHECK_STRUCT_LEN(8, virtchnl2_queue_reg_chunks);
 
@@ -703,7 +703,7 @@ struct virtchnl2_config_tx_queues {
 	__le32 vport_id;
 	__le16 num_qinfo;
 	u8 pad[10];
-	struct virtchnl2_txq_info qinfo[];
+	struct virtchnl2_txq_info qinfo[] __counted_by_le(num_qinfo);
 };
 VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_config_tx_queues);
 
@@ -782,7 +782,7 @@ struct virtchnl2_config_rx_queues {
 	__le32 vport_id;
 	__le16 num_qinfo;
 	u8 pad[18];
-	struct virtchnl2_rxq_info qinfo[];
+	struct virtchnl2_rxq_info qinfo[] __counted_by_le(num_qinfo);
 };
 VIRTCHNL2_CHECK_STRUCT_LEN(24, virtchnl2_config_rx_queues);
 
@@ -868,7 +868,7 @@ VIRTCHNL2_CHECK_STRUCT_LEN(32, virtchnl2_vector_chunk);
 struct virtchnl2_vector_chunks {
 	__le16 num_vchunks;
 	u8 pad[14];
-	struct virtchnl2_vector_chunk vchunks[];
+	struct virtchnl2_vector_chunk vchunks[] __counted_by_le(num_vchunks);
 };
 VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_vector_chunks);
 
@@ -912,7 +912,7 @@ struct virtchnl2_rss_lut {
 	__le16 lut_entries_start;
 	__le16 lut_entries;
 	u8 pad[4];
-	__le32 lut[];
+	__le32 lut[] __counted_by_le(lut_entries);
 };
 VIRTCHNL2_CHECK_STRUCT_LEN(12, virtchnl2_rss_lut);
 
@@ -977,7 +977,7 @@ struct virtchnl2_ptype {
 	u8 ptype_id_8;
 	u8 proto_id_count;
 	__le16 pad;
-	__le16 proto_id[];
+	__le16 proto_id[] __counted_by(proto_id_count);
 } __packed __aligned(2);
 VIRTCHNL2_CHECK_STRUCT_LEN(6, virtchnl2_ptype);
 
@@ -1104,7 +1104,7 @@ struct virtchnl2_rss_key {
 	__le32 vport_id;
 	__le16 key_len;
 	u8 pad;
-	u8 key_flex[];
+	u8 key_flex[] __counted_by_le(key_len);
 } __packed;
 VIRTCHNL2_CHECK_STRUCT_LEN(7, virtchnl2_rss_key);
 
@@ -1131,7 +1131,7 @@ VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_queue_chunk);
 struct virtchnl2_queue_chunks {
 	__le16 num_chunks;
 	u8 pad[6];
-	struct virtchnl2_queue_chunk chunks[];
+	struct virtchnl2_queue_chunk chunks[] __counted_by_le(num_chunks);
 };
 VIRTCHNL2_CHECK_STRUCT_LEN(8, virtchnl2_queue_chunks);
 
@@ -1195,7 +1195,7 @@ struct virtchnl2_queue_vector_maps {
 	__le32 vport_id;
 	__le16 num_qv_maps;
 	u8 pad[10];
-	struct virtchnl2_queue_vector qv_maps[];
+	struct virtchnl2_queue_vector qv_maps[] __counted_by_le(num_qv_maps);
 };
 VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_queue_vector_maps);
 
@@ -1247,7 +1247,7 @@ struct virtchnl2_mac_addr_list {
 	__le32 vport_id;
 	__le16 num_mac_addr;
 	u8 pad[2];
-	struct virtchnl2_mac_addr mac_addr_list[];
+	struct virtchnl2_mac_addr mac_addr_list[] __counted_by_le(num_mac_addr);
 };
 VIRTCHNL2_CHECK_STRUCT_LEN(8, virtchnl2_mac_addr_list);
 
-- 
2.44.0

Re: [PATCH net-next 3/3] idpf: sprinkle __counted_by{,_le}() in the virtchnl2 header

[Gustavo A. R. Silva]

On 3/26/24 10:41, Alexander Lobakin wrote:
> Both virtchnl2.h and its consumer idpf_virtchnl.c are very error-prone.
> There are 10 structures with flexible arrays at the end, but 9 of them
> has flex member counter in Little Endian.
> Make the code a bit more robust by applying __counted_by_le() to those
> 9. LE platforms is the main target for this driver, so they would
> receive additional protection.
> While we're here, add __counted_by() to virtchnl2_ptype::proto_id, as
> its counter is `u8` regardless of the Endianness.
> Compile test on x86_64 (LE) didn't reveal any new issues after applying
> the attributes.
> 
> Acked-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>

LGTM:

Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks
-- 
Gustavo

> ---
>   drivers/net/ethernet/intel/idpf/virtchnl2.h | 20 ++++++++++----------
>   1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/idpf/virtchnl2.h b/drivers/net/ethernet/intel/idpf/virtchnl2.h
> index 29419211b3d9..63deb120359c 100644
> --- a/drivers/net/ethernet/intel/idpf/virtchnl2.h
> +++ b/drivers/net/ethernet/intel/idpf/virtchnl2.h
> @@ -555,7 +555,7 @@ VIRTCHNL2_CHECK_STRUCT_LEN(32, virtchnl2_queue_reg_chunk);
>   struct virtchnl2_queue_reg_chunks {
>   	__le16 num_chunks;
>   	u8 pad[6];
> -	struct virtchnl2_queue_reg_chunk chunks[];
> +	struct virtchnl2_queue_reg_chunk chunks[] __counted_by_le(num_chunks);
>   };
>   VIRTCHNL2_CHECK_STRUCT_LEN(8, virtchnl2_queue_reg_chunks);
>   
> @@ -703,7 +703,7 @@ struct virtchnl2_config_tx_queues {
>   	__le32 vport_id;
>   	__le16 num_qinfo;
>   	u8 pad[10];
> -	struct virtchnl2_txq_info qinfo[];
> +	struct virtchnl2_txq_info qinfo[] __counted_by_le(num_qinfo);
>   };
>   VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_config_tx_queues);
>   
> @@ -782,7 +782,7 @@ struct virtchnl2_config_rx_queues {
>   	__le32 vport_id;
>   	__le16 num_qinfo;
>   	u8 pad[18];
> -	struct virtchnl2_rxq_info qinfo[];
> +	struct virtchnl2_rxq_info qinfo[] __counted_by_le(num_qinfo);
>   };
>   VIRTCHNL2_CHECK_STRUCT_LEN(24, virtchnl2_config_rx_queues);
>   
> @@ -868,7 +868,7 @@ VIRTCHNL2_CHECK_STRUCT_LEN(32, virtchnl2_vector_chunk);
>   struct virtchnl2_vector_chunks {
>   	__le16 num_vchunks;
>   	u8 pad[14];
> -	struct virtchnl2_vector_chunk vchunks[];
> +	struct virtchnl2_vector_chunk vchunks[] __counted_by_le(num_vchunks);
>   };
>   VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_vector_chunks);
>   
> @@ -912,7 +912,7 @@ struct virtchnl2_rss_lut {
>   	__le16 lut_entries_start;
>   	__le16 lut_entries;
>   	u8 pad[4];
> -	__le32 lut[];
> +	__le32 lut[] __counted_by_le(lut_entries);
>   };
>   VIRTCHNL2_CHECK_STRUCT_LEN(12, virtchnl2_rss_lut);
>   
> @@ -977,7 +977,7 @@ struct virtchnl2_ptype {
>   	u8 ptype_id_8;
>   	u8 proto_id_count;
>   	__le16 pad;
> -	__le16 proto_id[];
> +	__le16 proto_id[] __counted_by(proto_id_count);
>   } __packed __aligned(2);
>   VIRTCHNL2_CHECK_STRUCT_LEN(6, virtchnl2_ptype);
>   
> @@ -1104,7 +1104,7 @@ struct virtchnl2_rss_key {
>   	__le32 vport_id;
>   	__le16 key_len;
>   	u8 pad;
> -	u8 key_flex[];
> +	u8 key_flex[] __counted_by_le(key_len);
>   } __packed;
>   VIRTCHNL2_CHECK_STRUCT_LEN(7, virtchnl2_rss_key);
>   
> @@ -1131,7 +1131,7 @@ VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_queue_chunk);
>   struct virtchnl2_queue_chunks {
>   	__le16 num_chunks;
>   	u8 pad[6];
> -	struct virtchnl2_queue_chunk chunks[];
> +	struct virtchnl2_queue_chunk chunks[] __counted_by_le(num_chunks);
>   };
>   VIRTCHNL2_CHECK_STRUCT_LEN(8, virtchnl2_queue_chunks);
>   
> @@ -1195,7 +1195,7 @@ struct virtchnl2_queue_vector_maps {
>   	__le32 vport_id;
>   	__le16 num_qv_maps;
>   	u8 pad[10];
> -	struct virtchnl2_queue_vector qv_maps[];
> +	struct virtchnl2_queue_vector qv_maps[] __counted_by_le(num_qv_maps);
>   };
>   VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_queue_vector_maps);
>   
> @@ -1247,7 +1247,7 @@ struct virtchnl2_mac_addr_list {
>   	__le32 vport_id;
>   	__le16 num_mac_addr;
>   	u8 pad[2];
> -	struct virtchnl2_mac_addr mac_addr_list[];
> +	struct virtchnl2_mac_addr mac_addr_list[] __counted_by_le(num_mac_addr);
>   };
>   VIRTCHNL2_CHECK_STRUCT_LEN(8, virtchnl2_mac_addr_list);
>