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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-17 23:05:00 +0300 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2020-03-16 19:04:31 +0300 |
| commit | c0fb23f867b632293500d7900e0288cf17bfcb1a (patch) | |
| tree | 020d1d90be26ee830a5d57ba8d729821fd75839e /net/sunrpc/xprtrdma/svc_rdma_rw.c | |
| parent | 51cae673d036a32fe5cca9ec61765aa09e322c59 (diff) | |
| download | linux-c0fb23f867b632293500d7900e0288cf17bfcb1a.tar.xz | |
svcrdma: 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: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'net/sunrpc/xprtrdma/svc_rdma_rw.c')
| -rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_rw.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_rw.c b/net/sunrpc/xprtrdma/svc_rdma_rw.c index 48fe3b16b0d9..003610ce00bc 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_rw.c +++ b/net/sunrpc/xprtrdma/svc_rdma_rw.c @@ -41,7 +41,7 @@ struct svc_rdma_rw_ctxt { struct rdma_rw_ctx rw_ctx; int rw_nents; struct sg_table rw_sg_table; - struct scatterlist rw_first_sgl[0]; + struct scatterlist rw_first_sgl[]; }; static inline struct svc_rdma_rw_ctxt * |