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 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Ganapathi Bhat <ganapathi.bhat@nxp.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200225020413.GA8057@embeddedor
This commit is contained in:
Gustavo A. R. Silva 2020-02-24 20:04:13 -06:00 committed by Kalle Valo
parent 7b93071340
commit 2a6be797d2
3 changed files with 24 additions and 24 deletions

View file

@ -81,7 +81,7 @@ struct fwheader {
struct fwdata {
struct fwheader hdr;
__le32 seqnum;
uint8_t data[0];
uint8_t data[];
};
/** fwsyncheader */

View file

@ -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 {

View file

@ -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,