From patchwork Fri Apr 4 02:42:00 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 14038003 X-Patchwork-Delegate: johannes@sipsolutions.net Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AFCB32E62B4; Fri, 4 Apr 2025 02:42:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743734523; cv=none; b=H5ju5znDYbyeDzayV8KL7Tk8aKx/n8EgT0InoFFwwHEGTp5XqUYqUIBNESn0oLOgmEyCtQwW+A8YsO1oCZeRJ+jNn6LpPDYaGNKASnzFNAJxnueGlQyhsjENXQ1VNY0wIYF14ZyE0qoWECoa3JlErzOcqB6PEluGs8MT24LRIkM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743734523; c=relaxed/simple; bh=HEGvr219F+jjZb9/wuTWMlS78qKx3UrYGOaUQS8/10o=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=bgSUWeZQgpB1SI9SXdRTkB+2+A/dr/C3beC+uGuI6JNjuYWd8ZDZI5CRfPh5M3Rw766WzF7pJkCGKvkz1nUI0RFdOwIcHJK5rNnhCdjdnVSGzyU1h1xF0Wrazx9uAcIP5knqNaId5oa4nr0t2V6iGG8GthqZS8Hp34UPqNsvNiI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BVpmXOq9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BVpmXOq9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 879CCC4CEE3; Fri, 4 Apr 2025 02:42:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743734523; bh=HEGvr219F+jjZb9/wuTWMlS78qKx3UrYGOaUQS8/10o=; h=Date:From:To:Cc:Subject:From; b=BVpmXOq9/uEKXRJYI5q4UMXDDOB3QbzRgpssliD+ZKvK2uuElEqXMsztrJMpv2pHo q/79t9aQ6VQEJ3JNmUYC1X3wfXgxtWECAorb8ZBppR0Jk9kjdPbHiYromv9wmpqZsi W9OE3OfEgph3+EEOgyBrlfxsWnH3YNf8S5DtiJwY+kA7hiddOVVvphgYb8lKQhqg7l EEUwWFYj9hiTcSbPTFT0jI63PIO/i0L1fiGRIJwSPAhAb5ifCQfAvV5e1XU1sw4HXM IufllFMHgFo7waiZibC+DgM60GjfI6t+94dgLAoVBK44zoAEHt50BOI06rd80+vIWH ewdOnhs13HJ8w== Date: Thu, 3 Apr 2025 20:42:00 -0600 From: "Gustavo A. R. Silva" To: Miri Korenblit , Johannes Berg Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] wifi: iwlwifi: mvm/fw: Avoid -Wflex-array-member-not-at-end warnings Message-ID: Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline -Wflex-array-member-not-at-end was introduced in GCC-14, and we are getting ready to enable it, globally. So, in order to avoid ending up with a flexible-array member in the middle of multiple other structs, we use the `__struct_group()` helper to create a new tagged `struct iwl_tx_cmd_hdr`. This structure groups together all the members of the flexible `struct iwl_tx_cmd` except the flexible array. As a result, the array is effectively separated from the rest of the members without modifying the memory layout of the flexible structure. We then change the type of the middle struct members currently causing trouble from `struct iwl_tx_cmd` to `struct iwl_tx_cmd_hdr`. We also want to ensure that when new members need to be added to the flexible structure, they are always included within the newly created tagged struct. For this, we use `static_assert()`. This ensures that the memory layout for both the flexible structure and the new tagged struct is the same after any changes. This approach avoids having to implement `struct iwl_tx_cmd_hdr` as a completely separate structure, thus preventing having to maintain two independent but basically identical structures, closing the door to potential bugs in the future. We also use `container_of()` whenever we need to retrieve a pointer to the flexible structure, through which we can access the flexible-array member, if necessary. So, with these changes, fix the following warnings: drivers/net/wireless/intel/iwlwifi/mld/../fw/api/tdls.h:134:27: 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/mld/../fw/api/tdls.h:53:27: 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/mld/../fw/api/tx.h:745:27: 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/mld/../fw/api/tx.h:764:27: 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/../fw/api/tdls.h:134:27: 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/../fw/api/tdls.h:53:27: 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/../fw/api/tx.h:745:27: 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/../fw/api/tx.h:764:27: 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 --- This patch is quite similar to the following one: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e74c0a7875cfec27c25f582f001cc4625a0f8c07 Thanks! .../net/wireless/intel/iwlwifi/fw/api/tdls.h | 4 +- .../net/wireless/intel/iwlwifi/fw/api/tx.h | 60 ++++++++++--------- .../net/wireless/intel/iwlwifi/mvm/mac-ctxt.c | 8 ++- drivers/net/wireless/intel/iwlwifi/mvm/tdls.c | 10 ++-- 4 files changed, 44 insertions(+), 38 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/fw/api/tdls.h b/drivers/net/wireless/intel/iwlwifi/fw/api/tdls.h index cfa6532a3cdd..02198bc37f8c 100644 --- a/drivers/net/wireless/intel/iwlwifi/fw/api/tdls.h +++ b/drivers/net/wireless/intel/iwlwifi/fw/api/tdls.h @@ -50,7 +50,7 @@ struct iwl_tdls_channel_switch_timing { */ struct iwl_tdls_channel_switch_frame { __le32 switch_time_offset; - struct iwl_tx_cmd tx_cmd; + struct iwl_tx_cmd_hdr tx_cmd; u8 data[IWL_TDLS_CH_SW_FRAME_MAX_SIZE]; } __packed; /* TDLS_STA_CHANNEL_SWITCH_FRAME_API_S_VER_1 */ @@ -131,7 +131,7 @@ struct iwl_tdls_config_cmd { struct iwl_tdls_sta_info sta_info[IWL_TDLS_STA_COUNT]; __le32 pti_req_data_offset; - struct iwl_tx_cmd pti_req_tx_cmd; + struct iwl_tx_cmd_hdr pti_req_tx_cmd; u8 pti_req_template[]; } __packed; /* TDLS_CONFIG_CMD_API_S_VER_1 */ diff --git a/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h b/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h index 0a39e4b6eb62..5c0c7bac36d6 100644 --- a/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h +++ b/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h @@ -222,34 +222,36 @@ enum iwl_tx_offload_assist_flags_pos { * and then the actial payload. */ struct iwl_tx_cmd { - __le16 len; - __le16 offload_assist; - __le32 tx_flags; - struct { - u8 try_cnt; - u8 btkill_cnt; - __le16 reserved; - } scratch; /* DRAM_SCRATCH_API_U_VER_1 */ - __le32 rate_n_flags; - u8 sta_id; - u8 sec_ctl; - u8 initial_rate_index; - u8 reserved2; - u8 key[16]; - __le32 reserved3; - __le32 life_time; - __le32 dram_lsb_ptr; - u8 dram_msb_ptr; - u8 rts_retry_limit; - u8 data_retry_limit; - u8 tid_tspec; - __le16 pm_frame_timeout; - __le16 reserved4; - union { - DECLARE_FLEX_ARRAY(u8, payload); - DECLARE_FLEX_ARRAY(struct ieee80211_hdr, hdr); - }; + /* New members MUST be added within the __struct_group() macro below. */ + __struct_group(iwl_tx_cmd_hdr, __hdr, __packed, + __le16 len; + __le16 offload_assist; + __le32 tx_flags; + struct { + u8 try_cnt; + u8 btkill_cnt; + __le16 reserved; + } scratch; /* DRAM_SCRATCH_API_U_VER_1 */ + __le32 rate_n_flags; + u8 sta_id; + u8 sec_ctl; + u8 initial_rate_index; + u8 reserved2; + u8 key[16]; + __le32 reserved3; + __le32 life_time; + __le32 dram_lsb_ptr; + u8 dram_msb_ptr; + u8 rts_retry_limit; + u8 data_retry_limit; + u8 tid_tspec; + __le16 pm_frame_timeout; + __le16 reserved4; + ); + struct ieee80211_hdr hdr[]; } __packed; /* TX_CMD_API_S_VER_6 */ +static_assert(offsetof(struct iwl_tx_cmd, hdr) == sizeof(struct iwl_tx_cmd_hdr), + "struct member likely outside of __struct_group()"); struct iwl_dram_sec_info { __le32 pn_low; @@ -742,7 +744,7 @@ struct iwl_compressed_ba_notif { * @frame: the template of the beacon frame */ struct iwl_mac_beacon_cmd_v6 { - struct iwl_tx_cmd tx; + struct iwl_tx_cmd_hdr tx; __le32 template_id; __le32 tim_idx; __le32 tim_size; @@ -761,7 +763,7 @@ struct iwl_mac_beacon_cmd_v6 { * @frame: the template of the beacon frame */ struct iwl_mac_beacon_cmd_v7 { - struct iwl_tx_cmd tx; + struct iwl_tx_cmd_hdr tx; __le32 template_id; __le32 tim_idx; __le32 tim_size; diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c index bec18d197f31..f010e68b4a55 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c @@ -1032,7 +1032,9 @@ static int iwl_mvm_mac_ctxt_send_beacon_v6(struct iwl_mvm *mvm, struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif); struct iwl_mac_beacon_cmd_v6 beacon_cmd = {}; - iwl_mvm_mac_ctxt_set_tx(mvm, vif, beacon, &beacon_cmd.tx); + iwl_mvm_mac_ctxt_set_tx(mvm, vif, beacon, + container_of(&beacon_cmd.tx, + struct iwl_tx_cmd, __hdr)); beacon_cmd.template_id = cpu_to_le32((u32)mvmvif->id); @@ -1052,7 +1054,9 @@ static int iwl_mvm_mac_ctxt_send_beacon_v7(struct iwl_mvm *mvm, struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif); struct iwl_mac_beacon_cmd_v7 beacon_cmd = {}; - iwl_mvm_mac_ctxt_set_tx(mvm, vif, beacon, &beacon_cmd.tx); + iwl_mvm_mac_ctxt_set_tx(mvm, vif, beacon, + container_of(&beacon_cmd.tx, + struct iwl_tx_cmd, __hdr)); beacon_cmd.template_id = cpu_to_le32((u32)mvmvif->id); diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tdls.c b/drivers/net/wireless/intel/iwlwifi/mvm/tdls.c index 36379b738de1..bcfae05192ad 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/tdls.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/tdls.c @@ -342,6 +342,8 @@ iwl_mvm_tdls_config_channel_switch(struct iwl_mvm *mvm, struct iwl_tdls_channel_switch_cmd_tail *tail = iwl_mvm_chan_info_cmd_tail(mvm, &cmd.ci); u16 len = sizeof(cmd) - iwl_mvm_chan_info_padding(mvm); + struct iwl_tx_cmd *tx_cmd = + container_of(&tail->frame.tx_cmd, struct iwl_tx_cmd, __hdr); int ret; lockdep_assert_held(&mvm->mutex); @@ -410,14 +412,12 @@ iwl_mvm_tdls_config_channel_switch(struct iwl_mvm *mvm, ret = -EINVAL; goto out; } - iwl_mvm_set_tx_cmd_ccmp(info, &tail->frame.tx_cmd); + iwl_mvm_set_tx_cmd_ccmp(info, tx_cmd); } - iwl_mvm_set_tx_cmd(mvm, skb, &tail->frame.tx_cmd, info, - mvmsta->deflink.sta_id); + iwl_mvm_set_tx_cmd(mvm, skb, tx_cmd, info, mvmsta->deflink.sta_id); - iwl_mvm_set_tx_cmd_rate(mvm, &tail->frame.tx_cmd, info, sta, - hdr->frame_control); + iwl_mvm_set_tx_cmd_rate(mvm, tx_cmd, info, sta, hdr->frame_control); rcu_read_unlock(); memcpy(tail->frame.data, skb->data, skb->len);