linux-stable/include/net/nfc
Gustavo A. R. Silva da60fbe7ef NFC: 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 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-27 12:06:20 -08:00
..
digital.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288 2019-06-05 17:36:37 +02:00
hci.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
llc.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 399 2019-06-05 17:37:12 +02:00
nci.h NFC: Replace zero-length array with flexible-array member 2020-02-27 12:06:20 -08:00
nci_core.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
nfc.h NFC: Replace zero-length array with flexible-array member 2020-02-27 12:06:20 -08:00