diff options
author | Gustavo A. R. Silva <gustavoars@kernel.org> | 2020-05-07 14:26:47 -0500 |
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committer | Kalle Valo <kvalo@codeaurora.org> | 2020-05-12 11:56:55 +0300 |
commit | bd7db3021aa7a31f7d5122af1a863e66c75f88f5 (patch) | |
tree | 311d1a58cba98643d43a677787672fe662a9a1b4 /net/mac80211/fils_aead.h | |
parent | 55bb8a2b01a3f1531a5154457ec1c7041f5c6f9e (diff) |
rndis_wlan: Replace zero-length array with flexible-array
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]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
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 <gustavoars@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200507192647.GA16710@embeddedor
Diffstat (limited to 'net/mac80211/fils_aead.h')
0 files changed, 0 insertions, 0 deletions