diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-24 18:34:08 -0600 |
|---|---|---|
| committer | Kalle Valo <kvalo@codeaurora.org> | 2020-03-23 18:55:04 +0200 |
| commit | 398978f7dfa551abff9361f40db951c3c982fa5e (patch) | |
| tree | 0cec7bd55f62ed3cb9e179caae4448d6549e933a /drivers/net/wireless/ti/wl1251 | |
| parent | a1b7714b72fd2ba5dead01b465a9e37863051eff (diff) | |
wireless: ti: 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 <gustavo@embeddedor.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200225003408.GA28675@embeddedor
Diffstat (limited to 'drivers/net/wireless/ti/wl1251')
| -rw-r--r-- | drivers/net/wireless/ti/wl1251/cmd.h | 4 | ||||
| -rw-r--r-- | drivers/net/wireless/ti/wl1251/wl12xx_80211.h | 2 |
2 files changed, 3 insertions, 3 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 { |