diff options
author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-19 17:51:33 -0500 |
---|---|---|
committer | Kalle Valo <kvalo@codeaurora.org> | 2020-03-23 19:17:11 +0200 |
commit | b0c40588161dafdafdbac537b4441be02c15aff2 (patch) | |
tree | f23cd4aff803bcb7b07a7d5168a4cacb977bc378 /drivers/net | |
parent | 98d13639e6950b31e2e2e596a9bb58dada8b9f29 (diff) | |
download | linux-b0c40588161dafdafdbac537b4441be02c15aff2.tar.bz2 |
atmel: at76c50x: 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/20200319225133.GA29672@embeddedor.com
Diffstat (limited to 'drivers/net')
-rw-r--r-- | drivers/net/wireless/atmel/at76c50x-usb.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/wireless/atmel/at76c50x-usb.h b/drivers/net/wireless/atmel/at76c50x-usb.h index f56863403b05..746e64dfd8aa 100644 --- a/drivers/net/wireless/atmel/at76c50x-usb.h +++ b/drivers/net/wireless/atmel/at76c50x-usb.h @@ -151,7 +151,7 @@ struct at76_command { u8 cmd; u8 reserved; __le16 size; - u8 data[0]; + u8 data[]; } __packed; /* Length of Atmel-specific Rx header before 802.11 frame */ |