diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-24 19:11:51 -0600 |
|---|---|---|
| committer | Kalle Valo <kvalo@codeaurora.org> | 2020-03-23 18:59:15 +0200 |
| commit | bc1d50a1a485981784158c62b67c0268fdec5a10 (patch) | |
| tree | e2d2b3b928d4e7a998797594a2f69080e9952f3a /drivers/net/wireless | |
| parent | 398978f7dfa551abff9361f40db951c3c982fa5e (diff) | |
hostap: 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/20200225011151.GA30675@embeddedor
Diffstat (limited to 'drivers/net/wireless')
| -rw-r--r-- | drivers/net/wireless/intersil/hostap/hostap_common.h | 2 | ||||
| -rw-r--r-- | drivers/net/wireless/intersil/hostap/hostap_wlan.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/wireless/intersil/hostap/hostap_common.h b/drivers/net/wireless/intersil/hostap/hostap_common.h index 22543538239b..dd29a8e8d349 100644 --- a/drivers/net/wireless/intersil/hostap/hostap_common.h +++ b/drivers/net/wireless/intersil/hostap/hostap_common.h @@ -322,7 +322,7 @@ struct prism2_download_param { u32 addr; /* wlan card address */ u32 len; void __user *ptr; /* pointer to data in user space */ - } data[0]; + } data[]; }; #define PRISM2_MAX_DOWNLOAD_AREA_LEN 131072 diff --git a/drivers/net/wireless/intersil/hostap/hostap_wlan.h b/drivers/net/wireless/intersil/hostap/hostap_wlan.h index 487883fbb58c..dd2603d9b5d3 100644 --- a/drivers/net/wireless/intersil/hostap/hostap_wlan.h +++ b/drivers/net/wireless/intersil/hostap/hostap_wlan.h @@ -615,7 +615,7 @@ struct prism2_download_data { u32 addr; /* wlan card address */ u32 len; u8 *data; /* allocated data */ - } data[0]; + } data[]; }; |