Re: [PATCH v2] RDMA/rxe: fix the parent sysfs read when the interface has 15 chars

[Jason Gunthorpe <jgg@nvidia.com>]

On Thu, Aug 20, 2020 at 11:36:46PM +0800, Yi Zhang wrote:
> parent sysfs reads will yield '\0' bytes when the interface name
> has 15 chars, and there will no "\n" output.
> 
> reproducer:
> Create one interface with 15 chars
> [root@test ~]# ip a s enp0s29u1u7u3c2
> 2: enp0s29u1u7u3c2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN group default qlen 1000
>     link/ether 02:21:28:57:47:17 brd ff:ff:ff:ff:ff:ff
>     inet6 fe80::ac41:338f:5bcd:c222/64 scope link noprefixroute
>        valid_lft forever preferred_lft forever
> [root@test ~]# modprobe rdma_rxe
> [root@test ~]# echo enp0s29u1u7u3c2 > /sys/module/rdma_rxe/parameters/add
> [root@test ~]# cat /sys/class/infiniband/rxe0/parent
> enp0s29u1u7u3c2[root@test ~]#
> [root@test ~]# f="/sys/class/infiniband/rxe0/parent"
> [root@test ~]# echo "$(<"$f")"
> -bash: warning: command substitution: ignored null byte in input
> enp0s29u1u7u3c2
> 
> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Yi Zhang <yi.zhang@redhat.com>
> Reviewed-by: Bart Van Assche <bvanassche@acm.org>
> ---
>  drivers/infiniband/sw/rxe/rxe_verbs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Applied to for-rc with a Fixes and cc stable line

Thanks,
Jason