-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.
struct bss_bias_info is a flexible structure, this is a structure
that contains a flexible-array member (struct bss_bias bss_bias[]).
Since struct roam_ctrl_cmd is defined by hardware, we create the new
struct bss_bias_info_hdr type, and use it to replace the object type
causing trouble in struct roam_ctrl_cmd, namely struct bss_bias_info.
Also, once -fms-extensions is enabled, we can use transparent struct
members in struct bss_bias_info.
Notice that the newly created type does not contain the flex-array
member `bss_bias`, which is the object causing the -Wfamnae warning.
After these changes, the size of struct roam_ctrl_cmd, along
with its member's offsets remain the same, hence the memory layout
doesn't change:
Before changes:
struct roam_ctrl_cmd {
union {
u8 bssid[6]; /* 0 6 */
u8 roam_mode; /* 0 1 */
struct bss_bias_info bss; /* 0 1 */
struct low_rssi_scan_params params; /* 0 8 */
} info; /* 0 8 */
u8 roam_ctrl; /* 8 1 */
/* size: 9, cachelines: 1, members: 2 */
/* last cacheline: 9 bytes */
} __attribute__((__packed__));
After changes:
struct roam_ctrl_cmd {
union {
u8 bssid[6]; /* 0 6 */
u8 roam_mode; /* 0 1 */
struct bss_bias_info_hdr bss; /* 0 1 */
struct low_rssi_scan_params params; /* 0 8 */
} info; /* 0 8 */
u8 roam_ctrl; /* 8 1 */
/* size: 9, cachelines: 1, members: 2 */
/* last cacheline: 9 bytes */
} __attribute__((__packed__));
With these changes fix the following warning:
drivers/net/wireless/ath/ath6kl/wmi.h:1658:20: warning: structure containing a
flexible array member is not at the end of another structure
[-Wflex-array-member-not-at-end]
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
Changes in v2:
- Create new separate struct bss_bias_info_hdr, and use
transparent struct members (in struct bss_bias_info)
instead of rearranging members in struct roam_ctrl_cmd.
- Update subject line - Add 'wifi:' prefix.
v1:
- Link: https://lore.kernel.org/linux-hardening/aR153k4ExCD-QTMq@kspp/
drivers/net/wireless/ath/ath6kl/wmi.h | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/ath/ath6kl/wmi.h
b/drivers/net/wireless/ath/ath6kl/wmi.h
index 3080d82e25cc..d2a5c96fc878 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.h
+++ b/drivers/net/wireless/ath/ath6kl/wmi.h
@@ -1635,8 +1635,12 @@ struct bss_bias {
s8 bias;
} __packed;
-struct bss_bias_info {
+struct bss_bias_info_hdr {
u8 num_bss;
+} __packed;
+
+struct bss_bias_info {
+ struct bss_bias_info_hdr;
struct bss_bias bss_bias[];
} __packed;
@@ -1652,7 +1656,7 @@ struct roam_ctrl_cmd {
union {
u8 bssid[ETH_ALEN]; /* WMI_FORCE_ROAM */
u8 roam_mode; /* WMI_SET_ROAM_MODE */
- struct bss_bias_info bss; /* WMI_SET_HOST_BIAS */
+ struct bss_bias_info_hdr bss; /* WMI_SET_HOST_BIAS */
struct low_rssi_scan_params params; /* WMI_SET_LRSSI_SCAN_PARAMS
*/
} __packed info;
--
2.43.0
