wifi: iwlwifi: mvm: Use __counted_by() and avoid -Wfamnae warnings

-Wflex-array-member-not-at-end was introduced in GCC-14, and we are getting ready to enable it, globally.

So, use the DEFINE_FLEX() helper for multiple on-stack definitions of flexible structures where the size of their flexible-array members are known at compile-time, and refactor the rest of the code, accordingly.

In order to allow for the use of DEFINE_FLEX(), a couple of structures were annotated with the __counted_by() attribute.

With these changes, fix the following warnings:
drivers/net/wireless/intel/iwlwifi/mvm/d3.c:124:52: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/wireless/intel/iwlwifi/mvm/d3.c:2053:51: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/wireless/intel/iwlwifi/mvm/d3.c:2148:43: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/wireless/intel/iwlwifi/mvm/d3.c:2211:43: 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]>

---
 .../net/wireless/intel/iwlwifi/fw/api/sta.h   |   2 +-
 drivers/net/wireless/intel/iwlwifi/mvm/d3.c   | 126 ++++++++----------
 drivers/net/wireless/intel/iwlwifi/mvm/sta.c  |   2 +-
 include/net/mac80211.h                        |   2 +-
 4 files changed, 61 insertions(+), 71 deletions(-)

drivers/net/wireless/intel/iwlwifi/fw/api/sta.h +1 -1

index d7f8a276b683..fe6bd34fefa3 100644
@@ -479,7 +479,7 @@ struct iwl_mvm_wep_key_cmd {
        u8 decryption_type;
        u8 flags;
        u8 reserved;
-       struct iwl_mvm_wep_key wep_key[];
+       struct iwl_mvm_wep_key wep_key[] __counted_by(num_keys);
 } __packed; /* SEC_CURR_WEP_KEY_CMD_API_S_VER_2 */
 
 /**

drivers/net/wireless/intel/iwlwifi/mvm/d3.c +34 -42

index b4d650583ac2..b19579dd8de3 100644
@@ -120,19 +120,15 @@ static void iwl_mvm_wowlan_program_keys(struct ieee80211_hw *hw,
        switch (key->cipher) {
        case WLAN_CIPHER_SUITE_WEP40:
        case WLAN_CIPHER_SUITE_WEP104: { /* hack it for now */
-               struct {
-                       struct iwl_mvm_wep_key_cmd wep_key_cmd;
-                       struct iwl_mvm_wep_key wep_key;
-               } __packed wkc = {
-                       .wep_key_cmd.mac_id_n_color =
-                               cpu_to_le32(FW_CMD_ID_AND_COLOR(mvmvif->id,
-                                                               mvmvif->color)),
-                       .wep_key_cmd.num_keys = 1,
-                       /* firmware sets STA_KEY_FLG_WEP_13BYTES */
-                       .wep_key_cmd.decryption_type = STA_KEY_FLG_WEP,
-                       .wep_key.key_index = key->keyidx,
-                       .wep_key.key_size = key->keylen,
-               };
+               DEFINE_FLEX(struct iwl_mvm_wep_key_cmd, wkc, wep_key, num_keys, 1);
+
+               wkc->mac_id_n_color =
+                       cpu_to_le32(FW_CMD_ID_AND_COLOR(mvmvif->id,
+                                                       mvmvif->color));
+               /* firmware sets STA_KEY_FLG_WEP_13BYTES */
+               wkc->decryption_type = STA_KEY_FLG_WEP;
+               wkc->wep_key[0].key_index = key->keyidx;
+               wkc->wep_key[0].key_size = key->keylen;
 
                /*
                 * This will fail -- the key functions don't set support

@@ -142,18 +138,18 @@ static void iwl_mvm_wowlan_program_keys(struct ieee80211_hw *hw,
                if (key->flags & IEEE80211_KEY_FLAG_PAIRWISE)
                        break;
 
-               memcpy(&wkc.wep_key.key[3], key->key, key->keylen);
+               memcpy(&wkc->wep_key[0].key[3], key->key, key->keylen);
                if (key->keyidx == mvmvif->tx_key_idx) {
                        /* TX key must be at offset 0 */
-                       wkc.wep_key.key_offset = 0;
+                       wkc->wep_key[0].key_offset = 0;
                } else {
                        /* others start at 1 */
                        data->wep_key_idx++;
-                       wkc.wep_key.key_offset = data->wep_key_idx;
+                       wkc->wep_key[0].key_offset = data->wep_key_idx;
                }
 
                mutex_lock(&mvm->mutex);
-               ret = iwl_mvm_send_cmd_pdu(mvm, WEP_KEY, 0, sizeof(wkc), &wkc);
+               ret = iwl_mvm_send_cmd_pdu(mvm, WEP_KEY, 0, __struct_size(wkc), wkc);
                data->error = ret != 0;
 
                mvm->ptk_ivlen = key->iv_len;

@@ -2049,10 +2045,8 @@ static bool iwl_mvm_mlo_gtk_rekey(struct iwl_wowlan_status_data *status,
                struct iwl_wowlan_mlo_gtk *mlo_key = &status->mlo_keys[i];
                struct ieee80211_key_conf *key, *old_key;
                struct ieee80211_key_seq seq;
-               struct {
-                       struct ieee80211_key_conf conf;
-                       u8 key[32];
-               } conf = {};
+               DEFINE_FLEX(struct ieee80211_key_conf, conf, key, keylen,
+                           WOWLAN_KEY_MAX_SIZE);
                u16 flags = le16_to_cpu(mlo_key->flags);
                int j, link_id, key_id, key_type;
 

@@ -2069,40 +2063,40 @@ static bool iwl_mvm_mlo_gtk_rekey(struct iwl_wowlan_status_data *status,
                            key_type >= WOWLAN_MLO_GTK_KEY_NUM_TYPES))
                        continue;
 
-               conf.conf.cipher = old_keys->cipher[link_id][key_type];
+               conf->cipher = old_keys->cipher[link_id][key_type];
                /* WARN_ON? */
-               if (!conf.conf.cipher)
+               if (!conf->cipher)
                        continue;
 
-               conf.conf.keylen = 0;
-               switch (conf.conf.cipher) {
+               conf->keylen = 0;
+               switch (conf->cipher) {
                case WLAN_CIPHER_SUITE_CCMP:
                case WLAN_CIPHER_SUITE_GCMP:
-                       conf.conf.keylen = WLAN_KEY_LEN_CCMP;
+                       conf->keylen = WLAN_KEY_LEN_CCMP;
                        break;
                case WLAN_CIPHER_SUITE_GCMP_256:
-                       conf.conf.keylen = WLAN_KEY_LEN_GCMP_256;
+                       conf->keylen = WLAN_KEY_LEN_GCMP_256;
                        break;
                case WLAN_CIPHER_SUITE_BIP_GMAC_128:
-                       conf.conf.keylen = WLAN_KEY_LEN_BIP_GMAC_128;
+                       conf->keylen = WLAN_KEY_LEN_BIP_GMAC_128;
                        break;
                case WLAN_CIPHER_SUITE_BIP_GMAC_256:
-                       conf.conf.keylen = WLAN_KEY_LEN_BIP_GMAC_256;
+                       conf->keylen = WLAN_KEY_LEN_BIP_GMAC_256;
                        break;
                case WLAN_CIPHER_SUITE_AES_CMAC:
-                       conf.conf.keylen = WLAN_KEY_LEN_AES_CMAC;
+                       conf->keylen = WLAN_KEY_LEN_AES_CMAC;
                        break;
                case WLAN_CIPHER_SUITE_BIP_CMAC_256:
-                       conf.conf.keylen = WLAN_KEY_LEN_BIP_CMAC_256;
+                       conf->keylen = WLAN_KEY_LEN_BIP_CMAC_256;
                        break;
                }
 
-               if (WARN_ON(!conf.conf.keylen ||
-                           conf.conf.keylen > sizeof(conf.key)))
+               if (WARN_ON(!conf->keylen ||
+                           conf->keylen > WOWLAN_KEY_MAX_SIZE))
                        continue;
 
-               memcpy(conf.conf.key, mlo_key->key, conf.conf.keylen);
-               conf.conf.keyidx = key_id;
+               memcpy(conf->key, mlo_key->key, conf->keylen);
+               conf->keyidx = key_id;
 
                old_key = old_keys->key[link_id][key_id];
                if (old_key) {

@@ -2114,7 +2108,7 @@ static bool iwl_mvm_mlo_gtk_rekey(struct iwl_wowlan_status_data *status,
 
                IWL_DEBUG_WOWLAN(mvm, "Add MLO key id %d, link id %d\n",
                                 key_id, link_id);
-               key = ieee80211_gtk_rekey_add(vif, &conf.conf, link_id);
+               key = ieee80211_gtk_rekey_add(vif, conf, link_id);
                if (WARN_ON(IS_ERR(key))) {
                        ret = false;
                        goto out;

@@ -2144,30 +2138,28 @@ static bool iwl_mvm_gtk_rekey(struct iwl_wowlan_status_data *status,
 {
        int i, j;
        struct ieee80211_key_conf *key;
-       struct {
-               struct ieee80211_key_conf conf;
-               u8 key[32];
-       } conf = {
-               .conf.cipher = gtk_cipher,
-       };
+       DEFINE_FLEX(struct ieee80211_key_conf, conf, key, keylen,
+                   WOWLAN_KEY_MAX_SIZE);
        int link_id = vif->active_links ? __ffs(vif->active_links) : -1;
 
+       conf->cipher = gtk_cipher;
+