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authorGustavo A. R. Silva <gustavo@embeddedor.com>2020-03-24 00:48:10 +0300
committerGustavo A. R. Silva <gustavo@embeddedor.com>2020-04-18 23:44:54 +0300
commite76018cb604ace486de9cf85898c14bb2b47faff (patch)
treef5e46eaf568b3f88ddd8b8ee95135b052ed2883d /include/linux/can
parent5a58ec8cfc8621f5bdbd610202f62f817e5da204 (diff)
downloadlinux-e76018cb604ace486de9cf85898c14bb2b47faff.tar.xz
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/linux/can')
-rw-r--r--include/linux/can/dev/peak_canfd.h4
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 */