> -----Original Message-----
> From: Cheng Xu <chengyou@xxxxxxxxxxxxxxxxx>
> Sent: Thursday, 14 July 2022 03:31
> To: jgg@xxxxxxxx; leon@xxxxxxxxxx; Bernard Metzler <BMT@xxxxxxxxxxxxxx>
> Cc: linux-rdma@xxxxxxxxxxxxxxx; chengyou@xxxxxxxxxxxxxxxxx
> Subject: [EXTERNAL] [PATCH for-next] RDMA/siw: Fix duplicated reported
> IW_CM_EVENT_CONNECT_REPLY event
>
> If siw_recv_mpa_rr returns -EAGAIN, it means that the MPA reply hasn't
> been received completely, and should not report IW_CM_EVENT_CONNECT_REPLY
> in this case. This may trigger a call trace in iw_cm. A simple way to
> trigger this:
Great, thanks! I obviously did never hit an incomplete
MPA hdr. Please make another change to fix it correctly,
as suggested below.
case of an incomplete
> server: ib_send_lat
> client: ib_send_lat -R <server_ip>
>
> The call trace looks like this:
>
> kernel BUG at drivers/infiniband/core/iwcm.c:894!
> invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
> <...>
> Workqueue: iw_cm_wq cm_work_handler [iw_cm]
> Call Trace:
> <TASK>
> cm_work_handler+0x1dd/0x370 [iw_cm]
> process_one_work+0x1e2/0x3b0
> worker_thread+0x49/0x2e0
> ? rescuer_thread+0x370/0x370
> kthread+0xe5/0x110
> ? kthread_complete_and_exit+0x20/0x20
> ret_from_fork+0x1f/0x30
> </TASK>
>
> Signed-off-by: Cheng Xu <chengyou@xxxxxxxxxxxxxxxxx>
> ---
> drivers/infiniband/sw/siw/siw_cm.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/infiniband/sw/siw/siw_cm.c
> b/drivers/infiniband/sw/siw/siw_cm.c
> index 17f34d584cd9..f88d2971c2c6 100644
> --- a/drivers/infiniband/sw/siw/siw_cm.c
> +++ b/drivers/infiniband/sw/siw/siw_cm.c
> @@ -725,11 +725,11 @@ static int siw_proc_mpareply(struct siw_cep *cep)
> enum mpa_v2_ctrl mpa_p2p_mode = MPA_V2_RDMA_NO_RTR;
>
> rv = siw_recv_mpa_rr(cep);
> - if (rv != -EAGAIN)
> - siw_cancel_mpatimer(cep);
> if (rv)
> goto out_err;
>
> + siw_cancel_mpatimer(cep);
> +
Cancel the MPA timer only if we have a
real error. -EAGAIN translates to just
further waiting. So best to add the timer
cancellation to the error bailout section.
> rep = &cep->mpa.hdr;
>
> if (__mpa_rr_revision(rep->params.bits) > MPA_REVISION_2) {
> @@ -895,7 +895,8 @@ static int siw_proc_mpareply(struct siw_cep *cep)
> }
>
> out_err:
> - siw_cm_upcall(cep, IW_CM_EVENT_CONNECT_REPLY, -EINVAL);
> + if (rv != -EAGAIN)
{
cancel MPA timer here.
siw_cancel_mpatimer(cep);
> + siw_cm_upcall(cep, IW_CM_EVENT_CONNECT_REPLY, -EINVAL);
}
>
> return rv;
> }
> --
> 2.37.0
