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 <gustavo@xxxxxxxxxxxxxx>
---
drivers/net/wireless/ti/wl1251/cmd.h | 4 ++--
drivers/net/wireless/ti/wl1251/wl12xx_80211.h | 2 +-
drivers/net/wireless/ti/wlcore/acx.h | 2 +-
drivers/net/wireless/ti/wlcore/boot.h | 2 +-
drivers/net/wireless/ti/wlcore/cmd.h | 2 +-
drivers/net/wireless/ti/wlcore/conf.h | 2 +-
drivers/net/wireless/ti/wlcore/wl12xx_80211.h | 2 +-
7 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/net/wireless/ti/wl1251/cmd.h b/drivers/net/wireless/ti/wl1251/cmd.h
index 1c1a591c6055..e5874186f9d7 100644
--- a/drivers/net/wireless/ti/wl1251/cmd.h
+++ b/drivers/net/wireless/ti/wl1251/cmd.h
@@ -90,7 +90,7 @@ struct wl1251_cmd_header {
u16 id;
u16 status;
/* payload */
- u8 data[0];
+ u8 data[];
} __packed;
struct wl1251_command {
@@ -281,7 +281,7 @@ struct wl1251_cmd_packet_template {
struct wl1251_cmd_header header;
__le16 size;
- u8 data[0];
+ u8 data[];
} __packed;
#define TIM_ELE_ID 5
diff --git a/drivers/net/wireless/ti/wl1251/wl12xx_80211.h b/drivers/net/wireless/ti/wl1251/wl12xx_80211.h
index 7fabe702c4cc..7e28fe435b43 100644
--- a/drivers/net/wireless/ti/wl1251/wl12xx_80211.h
+++ b/drivers/net/wireless/ti/wl1251/wl12xx_80211.h
@@ -65,7 +65,7 @@ struct ieee80211_header {
u8 sa[ETH_ALEN];
u8 bssid[ETH_ALEN];
__le16 seq_ctl;
- u8 payload[0];
+ u8 payload[];
} __packed;
struct wl12xx_ie_header {
diff --git a/drivers/net/wireless/ti/wlcore/acx.h b/drivers/net/wireless/ti/wlcore/acx.h
index a265fba0cb4c..c725f5855c13 100644
--- a/drivers/net/wireless/ti/wlcore/acx.h
+++ b/drivers/net/wireless/ti/wlcore/acx.h
@@ -938,7 +938,7 @@ struct acx_rx_filter_cfg {
u8 action;
u8 num_fields;
- u8 fields[0];
+ u8 fields[];
} __packed;
struct acx_roaming_stats {
diff --git a/drivers/net/wireless/ti/wlcore/boot.h b/drivers/net/wireless/ti/wlcore/boot.h
index 14b367e98dce..24a2dfcb41ea 100644
--- a/drivers/net/wireless/ti/wlcore/boot.h
+++ b/drivers/net/wireless/ti/wlcore/boot.h
@@ -26,7 +26,7 @@ struct wl1271_static_data {
u8 fw_version[WL1271_FW_VERSION_MAX_LEN];
u32 hw_version;
u8 tx_power_table[WL1271_NO_SUBBANDS][WL1271_NO_POWER_LEVELS];
- u8 priv[0];
+ u8 priv[];
};
/* number of times we try to read the INIT interrupt */
diff --git a/drivers/net/wireless/ti/wlcore/cmd.h b/drivers/net/wireless/ti/wlcore/cmd.h
index bfad7b5a1ac6..f2609d5b6bf7 100644
--- a/drivers/net/wireless/ti/wlcore/cmd.h
+++ b/drivers/net/wireless/ti/wlcore/cmd.h
@@ -209,7 +209,7 @@ struct wl1271_cmd_header {
__le16 id;
__le16 status;
/* payload */
- u8 data[0];
+ u8 data[];
} __packed;
#define WL1271_CMD_MAX_PARAMS 572
diff --git a/drivers/net/wireless/ti/wlcore/conf.h b/drivers/net/wireless/ti/wlcore/conf.h
index 6116383ee248..31be425f2332 100644
--- a/drivers/net/wireless/ti/wlcore/conf.h
+++ b/drivers/net/wireless/ti/wlcore/conf.h
@@ -1150,7 +1150,7 @@ struct wlcore_conf {
struct wlcore_conf_file {
struct wlcore_conf_header header;
struct wlcore_conf core;
- u8 priv[0];
+ u8 priv[];
} __packed;
#endif
diff --git a/drivers/net/wireless/ti/wlcore/wl12xx_80211.h b/drivers/net/wireless/ti/wlcore/wl12xx_80211.h
index 181be725eff8..1dd7ecc11f86 100644
--- a/drivers/net/wireless/ti/wlcore/wl12xx_80211.h
+++ b/drivers/net/wireless/ti/wlcore/wl12xx_80211.h
@@ -66,7 +66,7 @@ struct ieee80211_header {
u8 sa[ETH_ALEN];
u8 bssid[ETH_ALEN];
__le16 seq_ctl;
- u8 payload[0];
+ u8 payload[];
} __packed;
struct wl12xx_ie_header {
--
2.25.0
