-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.
Move the conflicting declarations (which in a couple of cases happen
to be in a union, so the entire unions are moved) to the end of the
corresponding structures. Notice that `struct il_tx_beacon_cmd`,
`struct il4965_tx_resp`, and `struct il3945_tx_beacon_cmd` are flexible
structures, this is structures that contain a flexible-array member.
The case for struct il4965_beacon_notif is different. Since this
structure is defined by hardware, we use the struct_group() helper
to create the new `struct il4965_tx_resp_hdr` type. We then use this newly
created type to replace the obhect type of causing trouble in
struct il4965_beacon_notif, namely `stryct il4965_tx_resp`.
In order to preserve the memory layout in struct il4965_beacon_notif,
add member `__le32 beacon_tx_status`, which was previously included
by `struct il4965_tx_resp` (as `__le32 status`), but it's not present
in the newly created type `struct il4965_tx_resp_hdr`.
Notice that after this changes, the size of struct il4965_beacon_notif
along with its member's offsets remain the same, hence the memory
layout doesn't change:
Before changes:
struct il4965_beacon_notif {
struct il4965_tx_resp beacon_notify_hdr; /* 0 24 */
__le32 low_tsf; /* 24 4 */
__le32 high_tsf; /* 28 4 */
__le32 ibss_mgr_status; /* 32 4 */
/* size: 36, cachelines: 1, members: 4 */
/* last cacheline: 36 bytes */
};
After changes:
struct il4965_beacon_notif {
struct il4965_tx_resp_hdr beacon_notify_hdr; /* 0 20 */
__le32 beacon_tx_status; /* 20 4 */
__le32 low_tsf; /* 24 4 */
__le32 high_tsf; /* 28 4 */
__le32 ibss_mgr_status; /* 32 4 */
/* size: 36, cachelines: 1, members: 5 */
/* last cacheline: 36 bytes */
};
We also want to ensure that when new members are added to the flexible
structure `struct il4965_tx_resp` (if any), they are always included
within the newly created struct type. To enforce this, we use
`static_assert()` (which is intentionally placed right after the struct,
this is, no blank line in between). This ensures that the memory layout
of both the flexible structure and the new `struct il4965_tx_resp_hdr`
type remains consistent after any changes.
Lastly, refactor the rest of the code, accordingly.
With these changes fix the following warnings:
11 drivers/net/wireless/intel/iwlegacy/common.h:526:11: warning: structure
containing a flexible array member is not at the end of another structure
[-Wflex-array-member-not-at-end]
11 drivers/net/wireless/intel/iwlegacy/commands.h:2667:31: warning: structure
containing a flexible array member is not at the end of another structure
[-Wflex-array-member-not-at-end]
4 drivers/net/wireless/intel/iwlegacy/3945.h:131:11: 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:
- Use the struct_group() helper, and update the conflicting type
(struct il4965_tx_resp -> struct il4965_tx_resp_hdr) in
struct il4965_beacon_notif.
v1:
- Link: https://lore.kernel.org/linux-hardening/aR2CtqZI3atH0HmE@kspp/
drivers/net/wireless/intel/iwlegacy/3945.h | 4 +-
.../net/wireless/intel/iwlegacy/4965-mac.c | 2 +-
.../net/wireless/intel/iwlegacy/commands.h | 41 +++++++++++--------
drivers/net/wireless/intel/iwlegacy/common.h | 4 +-
4 files changed, 31 insertions(+), 20 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlegacy/3945.h
b/drivers/net/wireless/intel/iwlegacy/3945.h
index fb1e33c89d0e..ed63b31fee9a 100644
--- a/drivers/net/wireless/intel/iwlegacy/3945.h
+++ b/drivers/net/wireless/intel/iwlegacy/3945.h
@@ -123,13 +123,15 @@ enum il3945_antenna {
#define IEEE80211_FRAME_LEN (IEEE80211_DATA_LEN + IEEE80211_HLEN)
struct il3945_frame {
+ struct list_head list;
+
+ /* Must be last as it ends in a flexible-array member. */
union {
struct ieee80211_hdr frame;
struct il3945_tx_beacon_cmd beacon;
u8 raw[IEEE80211_FRAME_LEN];
u8 cmd[360];
} u;
- struct list_head list;
};
#define SUP_RATE_11A_MAX_NUM_CHANNELS 8
diff --git a/drivers/net/wireless/intel/iwlegacy/4965-mac.c
b/drivers/net/wireless/intel/iwlegacy/4965-mac.c
index 57fa866efd9f..f5a99a2ee95a 100644
--- a/drivers/net/wireless/intel/iwlegacy/4965-mac.c
+++ b/drivers/net/wireless/intel/iwlegacy/4965-mac.c
@@ -4076,7 +4076,7 @@ il4965_hdl_beacon(struct il_priv *il, struct il_rx_buf
*rxb)
u8 rate = il4965_hw_get_rate(beacon->beacon_notify_hdr.rate_n_flags);
D_RX("beacon status %x retries %d iss %d tsf:0x%.8x%.8x rate %d\n",
- le32_to_cpu(beacon->beacon_notify_hdr.u.status) & TX_STATUS_MSK,
+ le32_to_cpu(beacon->beacon_tx_status) & TX_STATUS_MSK,
beacon->beacon_notify_hdr.failure_frame,
le32_to_cpu(beacon->ibss_mgr_status),
le32_to_cpu(beacon->high_tsf), le32_to_cpu(beacon->low_tsf), rate);
diff --git a/drivers/net/wireless/intel/iwlegacy/commands.h
b/drivers/net/wireless/intel/iwlegacy/commands.h
index b61b8f377702..630bc12cd0d5 100644
--- a/drivers/net/wireless/intel/iwlegacy/commands.h
+++ b/drivers/net/wireless/intel/iwlegacy/commands.h
@@ -1691,22 +1691,25 @@ struct agg_tx_status {
} __packed;
struct il4965_tx_resp {
- u8 frame_count; /* 1 no aggregation, >1 aggregation */
- u8 bt_kill_count; /* # blocked by bluetooth (unused for agg) */
- u8 failure_rts; /* # failures due to unsuccessful RTS */
- u8 failure_frame; /* # failures due to no ACK (unused for agg) */
-
- /* For non-agg: Rate at which frame was successful.
- * For agg: Rate at which all frames were transmitted. */
- __le32 rate_n_flags; /* RATE_MCS_* */
-
- /* For non-agg: RTS + CTS + frame tx attempts time + ACK.
- * For agg: RTS + CTS + aggregation tx time + block-ack time. */
- __le16 wireless_media_time; /* uSecs */
-
- __le16 reserved;
- __le32 pa_power1; /* RF power amplifier measurement (not used) */
- __le32 pa_power2;
+ /* New members MUST be added within the __struct_group() macro below. */
+ __struct_group(il4965_tx_resp_hdr, __hdr, __packed,
+ u8 frame_count; /* 1 no aggregation, >1 aggregation */
+ u8 bt_kill_count; /* # blocked by bluetooth (unused for
agg) */
+ u8 failure_rts; /* # failures due to unsuccessful RTS */
+ u8 failure_frame; /* # failures due to no ACK (unused for
agg) */
+
+ /* For non-agg: Rate at which frame was successful.
+ * For agg: Rate at which all frames were transmitted. */
+ __le32 rate_n_flags; /* RATE_MCS_* */
+
+ /* For non-agg: RTS + CTS + frame tx attempts time + ACK.
+ * For agg: RTS + CTS + aggregation tx time + block-ack time.
*/
+ __le16 wireless_media_time; /* uSecs */
+
+ __le16 reserved;
+ __le32 pa_power1; /* RF power amplifier measurement (not
used) */
+ __le32 pa_power2;
+ );
/*
* For non-agg: frame status TX_STATUS_*
@@ -1726,6 +1729,9 @@ struct il4965_tx_resp {
DECLARE_FLEX_ARRAY(struct agg_tx_status, agg_status); /* for
each agg frame */
} u;
} __packed;
+static_assert(offsetof(struct il4965_tx_resp, u.agg_status) ==
+ sizeof(struct il4965_tx_resp_hdr),
+ "struct member likely outside of __struct_group()");
/*
* N_COMPRESSED_BA = 0xc5 (response only, not a command)
@@ -2664,7 +2670,8 @@ struct il3945_beacon_notif {
} __packed;
struct il4965_beacon_notif {
- struct il4965_tx_resp beacon_notify_hdr;
+ struct il4965_tx_resp_hdr beacon_notify_hdr;
+ __le32 beacon_tx_status;
__le32 low_tsf;
__le32 high_tsf;
__le32 ibss_mgr_status;
diff --git a/drivers/net/wireless/intel/iwlegacy/common.h
b/drivers/net/wireless/intel/iwlegacy/common.h
index 4c9836ab11dd..21f1c7702add 100644
--- a/drivers/net/wireless/intel/iwlegacy/common.h
+++ b/drivers/net/wireless/intel/iwlegacy/common.h
@@ -518,13 +518,15 @@ struct il_channel_info {
#define IEEE80211_FRAME_LEN (IEEE80211_DATA_LEN + IEEE80211_HLEN)
struct il_frame {
+ struct list_head list;
+
+ /* Must be last as it ends in a flexible-array member. */
union {
struct ieee80211_hdr frame;
struct il_tx_beacon_cmd beacon;
u8 raw[IEEE80211_FRAME_LEN];
u8 cmd[360];
} u;
- struct list_head list;
};
enum {
--
2.43.0
