diff options
author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-20 07:29:08 -0600 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-23 19:18:54 +0100 |
commit | 5979afa2c4d1c8acce28a176ebe27ea13265626a (patch) | |
tree | a4713b48315ba2506284f2e376c65ff0af3c871b /drivers/staging/wlan-ng | |
parent | cf7e44daa727bf4868a4b3be380829db52a2762d (diff) |
staging: 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>
Link: https://lore.kernel.org/r/20200220132908.GA30501@embeddedor
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/wlan-ng')
-rw-r--r-- | drivers/staging/wlan-ng/hfa384x.h | 4 | ||||
-rw-r--r-- | drivers/staging/wlan-ng/p80211types.h | 4 |
2 files changed, 4 insertions, 4 deletions
diff --git a/drivers/staging/wlan-ng/hfa384x.h b/drivers/staging/wlan-ng/hfa384x.h index bdd7f414fdbb..88e894dd3568 100644 --- a/drivers/staging/wlan-ng/hfa384x.h +++ b/drivers/staging/wlan-ng/hfa384x.h @@ -355,7 +355,7 @@ /* Commonly used basic types */ struct hfa384x_bytestr { __le16 len; - u8 data[0]; + u8 data[]; } __packed; struct hfa384x_bytestr32 { @@ -421,7 +421,7 @@ struct hfa384x_authenticate_station_data { /*-- Configuration Record: WPAData (data portion only) --*/ struct hfa384x_wpa_data { __le16 datalen; - u8 data[0]; /* max 80 */ + u8 data[]; /* max 80 */ } __packed; /*-------------------------------------------------------------------- diff --git a/drivers/staging/wlan-ng/p80211types.h b/drivers/staging/wlan-ng/p80211types.h index ac254542fde6..3dcdd022da61 100644 --- a/drivers/staging/wlan-ng/p80211types.h +++ b/drivers/staging/wlan-ng/p80211types.h @@ -204,7 +204,7 @@ struct p80211pstr { struct p80211pstrd { u8 len; - u8 data[0]; + u8 data[]; } __packed; /* Maximum pascal string */ @@ -249,7 +249,7 @@ struct p80211itemd { u32 did; u16 status; u16 len; - u8 data[0]; + u8 data[]; } __packed; /* message data item for int, BOUNDEDINT, ENUMINT */ |