diff options
author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-02 15:28:26 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2020-03-02 22:16:28 +0300 |
commit | 23640d641255be9d709c2eddfb0b37ca3c4aeabe (patch) | |
tree | 65e889ec4fb52ea6851856c7a6f18ae3b5ca6659 /drivers/net/ethernet/tehuti/tehuti.h | |
parent | ee3bc9c2232a5227ed8d5587759bf74a5413d7f9 (diff) | |
download | linux-23640d641255be9d709c2eddfb0b37ca3c4aeabe.tar.xz |
tehuti: 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: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/tehuti/tehuti.h')
-rw-r--r-- | drivers/net/ethernet/tehuti/tehuti.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ethernet/tehuti/tehuti.h b/drivers/net/ethernet/tehuti/tehuti.h index 5fc03c8eba0c..909e7296cecf 100644 --- a/drivers/net/ethernet/tehuti/tehuti.h +++ b/drivers/net/ethernet/tehuti/tehuti.h @@ -330,7 +330,7 @@ struct txd_desc { u16 length; u32 va_lo; u32 va_hi; - struct pbl pbl[0]; /* Fragments */ + struct pbl pbl[]; /* Fragments */ } __packed; /* Register region size */ |