On Thu, Aug 20, 2020 at 12:13:36PM +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 > > Signed-off-by: Yi Zhang <yi.zhang@xxxxxxxxxx> > drivers/infiniband/sw/rxe/rxe_verbs.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c > index bb61e534e468..91090cb1b08c 100644 > +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c > @@ -1056,7 +1056,7 @@ static ssize_t parent_show(struct device *device, > struct rxe_dev *rxe = > rdma_device_to_drv_device(device, struct rxe_dev, ib_dev); > > - return snprintf(buf, 16, "%s\n", rxe_parent_name(rxe, 1)); > + return snprintf(buf, 17, "%s\n", rxe_parent_name(rxe, 1)); > } This should be written as return scnprintf(buf, PAGE_SIZE, "%s\n", rxe_parent_name(rxe, 1)); All places in this file should be changed Jason
