diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-12 19:04:25 -0600 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2020-02-20 13:33:51 -0400 |
| commit | 5b361328ca649534d721e4eae20c96ccbe702ce7 (patch) | |
| tree | aecd94c8ba19a810b66a90a2914b5834ba2832a4 /include/rdma/ib_verbs.h | |
| parent | 52c5e9e7497b728b53a84cbd5873c4b707d10d55 (diff) | |
RDMA: 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")
Link: https://lore.kernel.org/r/20200213010425.GA13068@embeddedor.com
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> # added a few more
Diffstat (limited to 'include/rdma/ib_verbs.h')
| -rw-r--r-- | include/rdma/ib_verbs.h | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index 5f3a04ead9f5..bbc5cfb57cd2 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -1876,7 +1876,7 @@ struct ib_flow_eth_filter { __be16 ether_type; __be16 vlan_tag; /* Must be last */ - u8 real_sz[0]; + u8 real_sz[]; }; struct ib_flow_spec_eth { @@ -1890,7 +1890,7 @@ struct ib_flow_ib_filter { __be16 dlid; __u8 sl; /* Must be last */ - u8 real_sz[0]; + u8 real_sz[]; }; struct ib_flow_spec_ib { @@ -1915,7 +1915,7 @@ struct ib_flow_ipv4_filter { u8 ttl; u8 flags; /* Must be last */ - u8 real_sz[0]; + u8 real_sz[]; }; struct ib_flow_spec_ipv4 { @@ -1933,7 +1933,7 @@ struct ib_flow_ipv6_filter { u8 traffic_class; u8 hop_limit; /* Must be last */ - u8 real_sz[0]; + u8 real_sz[]; }; struct ib_flow_spec_ipv6 { @@ -1947,7 +1947,7 @@ struct ib_flow_tcp_udp_filter { __be16 dst_port; __be16 src_port; /* Must be last */ - u8 real_sz[0]; + u8 real_sz[]; }; struct ib_flow_spec_tcp_udp { @@ -1959,7 +1959,7 @@ struct ib_flow_spec_tcp_udp { struct ib_flow_tunnel_filter { __be32 tunnel_id; - u8 real_sz[0]; + u8 real_sz[]; }; /* ib_flow_spec_tunnel describes the Vxlan tunnel @@ -1976,7 +1976,7 @@ struct ib_flow_esp_filter { __be32 spi; __be32 seq; /* Must be last */ - u8 real_sz[0]; + u8 real_sz[]; }; struct ib_flow_spec_esp { @@ -1991,7 +1991,7 @@ struct ib_flow_gre_filter { __be16 protocol; __be32 key; /* Must be last */ - u8 real_sz[0]; + u8 real_sz[]; }; struct ib_flow_spec_gre { @@ -2004,7 +2004,7 @@ struct ib_flow_spec_gre { struct ib_flow_mpls_filter { __be32 tag; /* Must be last */ - u8 real_sz[0]; + u8 real_sz[]; }; struct ib_flow_spec_mpls { |