Re: [PATCH iproute2-rc 1/2] rdma: Fix core dump when pretty is used

Stephen Hemminger
2023-12-29T17:21:31Z

On Fri, 29 Dec 2023 14:52:40 +0800
Junxian Huang <huangjunxian6@hisilicon.com> wrote:

> From: Chengchang Tang <tangchengchang@huawei.com>
>
> There will be a core dump when pretty is used as the JSON object
> hasn't been opened and closed properly.
>
> Before:
> $ rdma res show qp -jp -dd
> [ {
> "ifindex": 1,
> "ifname": "hns_1",
> "port": 1,
> "lqpn": 1,
> "type": "GSI",
> "state": "RTS",
> "sq-psn": 0,
> "comm": "ib_core"
> },
> "drv_sq_wqe_cnt": 128,
> "drv_sq_max_gs": 2,
> "drv_rq_wqe_cnt": 512,
> "drv_rq_max_gs": 1,
> rdma: json_writer.c:130: jsonw_end: Assertion `self->depth > 0' failed.
> Aborted (core dumped)
>
> After:
> $ rdma res show qp -jp -dd
> [ {
> "ifindex": 2,
> "ifname": "hns_2",
> "port": 1,
> "lqpn": 1,
> "type": "GSI",
> "state": "RTS",
> "sq-psn": 0,
> "comm": "ib_core",{
> "drv_sq_wqe_cnt": 128,
> "drv_sq_max_gs": 2,
> "drv_rq_wqe_cnt": 512,
> "drv_rq_max_gs": 1,
> "drv_ext_sge_sge_cnt": 256
> }
> } ]
>
> Fixes: 331152752a97 ("rdma: print driver resource attributes")
> Signed-off-by: Chengchang Tang <tangchengchang@huawei.com>
> Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>

This code in rdma seems to be miking json and newline functionality
which creates bug traps.

Also the json should have same effective output in pretty and non-pretty mode.
It looks like since pretty mode add extra object layer, the nesting of {} would be
different.

The conversion to json_print() was done but it isn't using same conventions
as ip or tc.

The correct fix needs to go deeper and hit other things.