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 /drivers/infiniband/core/cm.c | |
| 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 'drivers/infiniband/core/cm.c')
| -rw-r--r-- | drivers/infiniband/core/cm.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c index 33c0d9e7bb66..aec6867f0ed2 100644 --- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -197,7 +197,7 @@ struct cm_device { struct ib_device *ib_device; u8 ack_delay; int going_down; - struct cm_port *port[0]; + struct cm_port *port[]; }; struct cm_av { @@ -216,7 +216,7 @@ struct cm_work { __be32 local_id; /* Established / timewait */ __be32 remote_id; struct ib_cm_event cm_event; - struct sa_path_rec path[0]; + struct sa_path_rec path[]; }; struct cm_timewait_info { |