diff options
author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-19 16:32:26 -0500 |
---|---|---|
committer | Wei Liu <wei.liu@kernel.org> | 2020-03-21 16:26:12 +0000 |
commit | 032d4a4802209fe25ce44deb2c002dccf663925f (patch) | |
tree | 1538ad4ea320bc32f78115b1b729fedf27967b31 /drivers/hv | |
parent | fb33c6510d5595144d585aa194d377cf74d31911 (diff) |
hv: hyperv_vmbus.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>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'drivers/hv')
-rw-r--r-- | drivers/hv/hyperv_vmbus.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index f5fa3b3c9baf..70b30e223a57 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -292,7 +292,7 @@ struct vmbus_msginfo { struct list_head msglist_entry; /* The message itself */ - unsigned char msg[0]; + unsigned char msg[]; }; |