diff options
author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-03 00:04:37 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2020-03-04 04:39:19 +0300 |
commit | 30a87f150bd605feca716c056ef9a9ebb1fee1f9 (patch) | |
tree | 7491f581119b68de14359080f414ca2aa2fb63a3 /drivers/net/ethernet/mellanox/mlxfw | |
parent | e6a98f8081e296bc225f5952b3dff1530c7f3192 (diff) | |
download | linux-30a87f150bd605feca716c056ef9a9ebb1fee1f9.tar.xz |
net: mlxfw: 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>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/mellanox/mlxfw')
-rw-r--r-- | drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2.c | 2 | ||||
-rw-r--r-- | drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2_tlv.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2.c b/drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2.c index 79057af4fe99..5d9ddf36fb4e 100644 --- a/drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2.c +++ b/drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2.c @@ -496,7 +496,7 @@ mlxfw_mfa2_file_component_tlv_get(const struct mlxfw_mfa2_file *mfa2_file, struct mlxfw_mfa2_comp_data { struct mlxfw_mfa2_component comp; - u8 buff[0]; + u8 buff[]; }; static const struct mlxfw_mfa2_tlv_component_descriptor * diff --git a/drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2_tlv.h b/drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2_tlv.h index 33c971190bba..2014a5de5a01 100644 --- a/drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2_tlv.h +++ b/drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2_tlv.h @@ -11,7 +11,7 @@ struct mlxfw_mfa2_tlv { u8 version; u8 type; __be16 len; - u8 data[0]; + u8 data[]; } __packed; static inline const struct mlxfw_mfa2_tlv * |