linux-stable/net/sunrpc/xprtrdma
Gustavo A. R. Silva c0fb23f867 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 7649773293 ("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>
2020-03-16 12:04:31 -04:00
..
backchannel.c xprtrdma: Allocate and map transport header buffers at connect time 2020-01-15 10:54:32 -05:00
frwr_ops.c xprtrdma: Fix DMA scatter-gather list mapping imbalance 2020-02-13 15:35:33 -05:00
Makefile xprtrdma: Remove support for FMR memory registration 2019-01-02 12:05:17 -05:00
module.c NFS client updates for Linux 4.18 2018-06-12 10:09:03 -07:00
rpc_rdma.c xprtrdma: Allocate and map transport header buffers at connect time 2020-01-15 10:54:32 -05:00
svc_rdma.c svcrdma: Remove svc_rdma_wq 2019-08-19 10:59:28 -04:00
svc_rdma_backchannel.c SUNRPC: Fix backchannel latency metrics 2019-11-21 17:05:14 -05:00
svc_rdma_recvfrom.c svcrdma: Use llist for managing cache of recv_ctxts 2019-08-19 10:59:28 -04:00
svc_rdma_rw.c svcrdma: Replace zero-length array with flexible-array member 2020-03-16 12:04:31 -04:00
svc_rdma_sendto.c svcrdma: Improve DMA mapping trace points 2019-10-08 16:01:33 -04:00
svc_rdma_transport.c Highlights: 2019-09-27 17:00:27 -07:00
transport.c xprtrdma: Eliminate per-transport "max pages" 2020-01-15 10:54:32 -05:00
verbs.c xprtrdma: DMA map rr_rdma_buf as each rpcrdma_rep is created 2020-01-15 10:54:32 -05:00
xprt_rdma.h xprtrdma: Allocate and map transport header buffers at connect time 2020-01-15 10:54:32 -05:00