diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-23 16:48:10 -0500 |
|---|---|---|
| committer | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-04-18 15:44:54 -0500 |
| commit | e76018cb604ace486de9cf85898c14bb2b47faff (patch) | |
| tree | f5e46eaf568b3f88ddd8b8ee95135b052ed2883d /include | |
| parent | 5a58ec8cfc8621f5bdbd610202f62f817e5da204 (diff) | |
can: dev: peak_canfd.h: 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>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/can/dev/peak_canfd.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/can/dev/peak_canfd.h b/include/linux/can/dev/peak_canfd.h index 511a37302fea..5fd627e9da19 100644 --- a/include/linux/can/dev/peak_canfd.h +++ b/include/linux/can/dev/peak_canfd.h @@ -189,7 +189,7 @@ struct __packed pucan_rx_msg { u8 client; __le16 flags; __le32 can_id; - u8 d[0]; + u8 d[]; }; /* uCAN error types */ @@ -266,7 +266,7 @@ struct __packed pucan_tx_msg { u8 client; __le16 flags; __le32 can_id; - u8 d[0]; + u8 d[]; }; /* build the cmd opcode_channel field with respect to the correct endianness */ |