From 2a6be797d232a4aec7be013964a5c2b8a1a46a3e Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Mon, 24 Feb 2020 20:04:13 -0600 Subject: [PATCH] wireless: marvell: Replace zero-length array with flexible-array member The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Acked-by: Ganapathi Bhat Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20200225020413.GA8057@embeddedor --- drivers/net/wireless/marvell/libertas_tf/if_usb.h | 2 +- drivers/net/wireless/marvell/mwifiex/fw.h | 40 +++++++++++------------ drivers/net/wireless/marvell/mwl8k.c | 6 ++-- 3 files changed, 24 insertions(+), 24 deletions(-) diff --git a/drivers/net/wireless/marvell/libertas_tf/if_usb.h b/drivers/net/wireless/marvell/libertas_tf/if_usb.h index 585ad36..f6dd737 100644 --- a/drivers/net/wireless/marvell/libertas_tf/if_usb.h +++ b/drivers/net/wireless/marvell/libertas_tf/if_usb.h @@ -81,7 +81,7 @@ struct fwheader { struct fwdata { struct fwheader hdr; __le32 seqnum; - uint8_t data[0]; + uint8_t data[]; }; /** fwsyncheader */ diff --git a/drivers/net/wireless/marvell/mwifiex/fw.h b/drivers/net/wireless/marvell/mwifiex/fw.h index 4dfdf92..a415d73 100644 --- a/drivers/net/wireless/marvell/mwifiex/fw.h +++ b/drivers/net/wireless/marvell/mwifiex/fw.h @@ -846,7 +846,7 @@ struct mwifiex_ie_types_random_mac { struct mwifiex_ietypes_chanstats { struct mwifiex_ie_types_header header; - struct mwifiex_fw_chan_stats chanstats[0]; + struct mwifiex_fw_chan_stats chanstats[]; } __packed; struct mwifiex_ie_types_wildcard_ssid_params { @@ -1082,7 +1082,7 @@ struct host_cmd_ds_get_hw_spec { __le32 reserved_6; __le32 dot_11ac_dev_cap; __le32 dot_11ac_mcs_support; - u8 tlvs[0]; + u8 tlvs[]; } __packed; struct host_cmd_ds_802_11_rssi_info { @@ -1140,7 +1140,7 @@ struct ieee_types_assoc_rsp { __le16 cap_info_bitmap; __le16 status_code; __le16 a_id; - u8 ie_buffer[0]; + u8 ie_buffer[]; } __packed; struct host_cmd_ds_802_11_associate_rsp { @@ -1455,7 +1455,7 @@ struct host_cmd_ds_chan_rpt_event { __le32 result; __le64 start_tsf; __le32 duration; - u8 tlvbuf[0]; + u8 tlvbuf[]; } __packed; struct host_cmd_sdio_sp_rx_aggr_cfg { @@ -1625,7 +1625,7 @@ struct host_cmd_ds_802_11_bg_scan_config { __le32 reserved2; __le32 report_condition; __le16 reserved3; - u8 tlv[0]; + u8 tlv[]; } __packed; struct host_cmd_ds_802_11_bg_scan_query { @@ -1720,7 +1720,7 @@ struct mwifiex_ie_types_sta_info { struct host_cmd_ds_sta_list { __le16 sta_count; - u8 tlv[0]; + u8 tlv[]; } __packed; struct mwifiex_ie_types_pwr_capability { @@ -1743,7 +1743,7 @@ struct mwifiex_ie_types_wmm_param_set { struct mwifiex_ie_types_mgmt_frame { struct mwifiex_ie_types_header header; __le16 frame_control; - u8 frame_contents[0]; + u8 frame_contents[]; }; struct mwifiex_ie_types_wmm_queue_status { @@ -1861,7 +1861,7 @@ struct mwifiex_ie_types_2040bssco { struct mwifiex_ie_types_extcap { struct mwifiex_ie_types_header header; - u8 ext_capab[0]; + u8 ext_capab[]; } __packed; struct host_cmd_ds_mem_access { @@ -1918,12 +1918,12 @@ struct mwifiex_assoc_event { __le16 frame_control; __le16 cap_info; __le16 listen_interval; - u8 data[0]; + u8 data[]; } __packed; struct host_cmd_ds_sys_config { __le16 action; - u8 tlv[0]; + u8 tlv[]; }; struct host_cmd_11ac_vht_cfg { @@ -1956,7 +1956,7 @@ struct host_cmd_tlv_gwk_cipher { struct host_cmd_tlv_passphrase { struct mwifiex_ie_types_header header; - u8 passphrase[0]; + u8 passphrase[]; } __packed; struct host_cmd_tlv_wep_key { @@ -1978,12 +1978,12 @@ struct host_cmd_tlv_encrypt_protocol { struct host_cmd_tlv_ssid { struct mwifiex_ie_types_header header; - u8 ssid[0]; + u8 ssid[]; } __packed; struct host_cmd_tlv_rates { struct mwifiex_ie_types_header header; - u8 rates[0]; + u8 rates[]; } __packed; struct mwifiex_ie_types_bssid_list { @@ -2100,13 +2100,13 @@ struct mwifiex_fw_mef_entry { u8 mode; u8 action; __le16 exprsize; - u8 expr[0]; + u8 expr[]; } __packed; struct host_cmd_ds_mef_cfg { __le32 criteria; __le16 num_entries; - struct mwifiex_fw_mef_entry mef_entry[0]; + struct mwifiex_fw_mef_entry mef_entry[]; } __packed; #define CONNECTION_TYPE_INFRA 0 @@ -2169,7 +2169,7 @@ struct mwifiex_radar_det_event { struct mwifiex_ie_types_multi_chan_info { struct mwifiex_ie_types_header header; __le16 status; - u8 tlv_buffer[0]; + u8 tlv_buffer[]; } __packed; struct mwifiex_ie_types_mc_group_info { @@ -2185,7 +2185,7 @@ struct mwifiex_ie_types_mc_group_info { u8 usb_ep_num; } hid_num; u8 intf_num; - u8 bss_type_numlist[0]; + u8 bss_type_numlist[]; } __packed; struct meas_rpt_map { @@ -2250,13 +2250,13 @@ struct coalesce_receive_filt_rule { u8 num_of_fields; u8 pkt_type; __le16 max_coalescing_delay; - struct coalesce_filt_field_param params[0]; + struct coalesce_filt_field_param params[]; } __packed; struct host_cmd_ds_coalesce_cfg { __le16 action; __le16 num_of_rules; - struct coalesce_receive_filt_rule rule[0]; + struct coalesce_receive_filt_rule rule[]; } __packed; struct host_cmd_ds_multi_chan_policy { @@ -2295,7 +2295,7 @@ struct host_cmd_ds_pkt_aggr_ctrl { struct host_cmd_ds_sta_configure { __le16 action; - u8 tlv_buffer[0]; + u8 tlv_buffer[]; } __packed; struct host_cmd_ds_command { diff --git a/drivers/net/wireless/marvell/mwl8k.c b/drivers/net/wireless/marvell/mwl8k.c index d55f229..47fb4b3e 100644 --- a/drivers/net/wireless/marvell/mwl8k.c +++ b/drivers/net/wireless/marvell/mwl8k.c @@ -592,7 +592,7 @@ struct mwl8k_cmd_pkt { __u8 seq_num; __u8 macid; __le16 result; - char payload[0]; + char payload[]; } __packed; /* @@ -806,7 +806,7 @@ static int mwl8k_load_firmware(struct ieee80211_hw *hw) struct mwl8k_dma_data { __le16 fwlen; struct ieee80211_hdr wh; - char data[0]; + char data[]; } __packed; /* Routines to add/remove DMA header from skb. */ @@ -2955,7 +2955,7 @@ mwl8k_cmd_rf_antenna(struct ieee80211_hw *hw, int antenna, int mask) struct mwl8k_cmd_set_beacon { struct mwl8k_cmd_pkt header; __le16 beacon_len; - __u8 beacon[0]; + __u8 beacon[]; }; static int mwl8k_cmd_set_beacon(struct ieee80211_hw *hw, -- 2.7.4