diff options
author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-05-04 23:12:24 +0300 |
---|---|---|
committer | Kalle Valo <kvalo@codeaurora.org> | 2020-05-06 09:23:08 +0300 |
commit | 14dd3a71ccb7081d5d4959370794bbabc3258b34 (patch) | |
tree | 5a21c79352f77bc30d97dfba228e0c60439c9a1d /drivers/net/wireless/ath/ath11k/debug.h | |
parent | 450edd2805982d14ed79733a82927d2857b27cac (diff) | |
download | linux-14dd3a71ccb7081d5d4959370794bbabc3258b34.tar.xz |
ath11k: 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 <gustavo@embeddedor.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200504201224.GA32282@embeddedor
Diffstat (limited to 'drivers/net/wireless/ath/ath11k/debug.h')
-rw-r--r-- | drivers/net/wireless/ath/ath11k/debug.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/wireless/ath/ath11k/debug.h b/drivers/net/wireless/ath/ath11k/debug.h index f8aa48e39703..c30085406bfb 100644 --- a/drivers/net/wireless/ath/ath11k/debug.h +++ b/drivers/net/wireless/ath/ath11k/debug.h @@ -67,7 +67,7 @@ struct debug_htt_stats_req { u8 peer_addr[ETH_ALEN]; struct completion cmpln; u32 buf_len; - u8 buf[0]; + u8 buf[]; }; struct ath_pktlog_hdr { @@ -77,7 +77,7 @@ struct ath_pktlog_hdr { u16 size; u32 timestamp; u32 type_specific_data; - u8 payload[0]; + u8 payload[]; }; #define ATH11K_HTT_PEER_STATS_RESET BIT(16) |