On 4/11/22 11:25, Pearson, Robert B wrote:
> Zhu,
>
> Would you be willing to try the v13 pool patch series. It also fixes the blktests bug.
> (You have to apply Bart's scsi_debug revert patch to fix that issue.)
> I think it may also fix this issue because it is way more careful about deferring qp cleanup
> code until after all the packets have completed.
>
> The bug you are seeing feels like a race with qp destroy.
>
> Bob
>
> -----Original Message-----
> From: Zhu Yanjun <zyjzyj2000@xxxxxxxxx>
> Sent: Monday, April 11, 2022 12:34 AM
> To: Bob Pearson <rpearsonhpe@xxxxxxxxx>
> Cc: linux-rdma@xxxxxxxxxxxxxxx
> Subject: Re: null pointer in rxe_mr_copy()
>
> On Mon, Apr 11, 2022 at 1:14 PM Zhu Yanjun <zyjzyj2000@xxxxxxxxx> wrote:
>>
>> On Mon, Apr 11, 2022 at 11:34 AM Bob Pearson <rpearsonhpe@xxxxxxxxx> wrote:
>>>
>>> Zhu,
>>>
>>> Since checking for mr == NULL in rxe_mr_copy fixes the problem you were seeing in rping.
>>> Perhaps it would be a good idea to apply the following patch which
>>> would tell us which of the three calls to rxe_mr_copy is failing. My
>>> suspicion is the one in read_reply()
>> Hi, Bob
>>
>> Yes. It is the function read_reply.
>
> 720 static enum resp_states read_reply(struct rxe_qp *qp,
> 721 struct rxe_pkt_info *req_pkt)
> 722 {
> 723 struct rxe_pkt_info ack_pkt;
> 724 struct sk_buff *skb;
> 725 int mtu = qp->mtu;
> 726 enum resp_states state;
> 727 int payload;
> 728 int opcode;
> 729 int err;
> 730 struct resp_res *res = qp->resp.res;
> 731 struct rxe_mr *mr;
> 732
> 733 if (!res) {
> 734 res = rxe_prepare_read_res(qp, req_pkt);
> 735 qp->resp.res = res;
> 736 }
> 737
> 738 if (res->state == rdatm_res_state_new) {
> 739 mr = qp->resp.mr;
> <----It seems that mr is from here.
> 740 qp->resp.mr = NULL;
> 741
>
>
>>
>> kernel: ------------[ cut here ]------------
>> kernel: WARNING: CPU: 74 PID: 38510 at
>> drivers/infiniband/sw/rxe/rxe_resp.c:768 rxe_responder+0x1d67/0x1dd0
>> [rdma_rxe]
>> kernel: Modules linked in: rdma_rxe(OE) ip6_udp_tunnel udp_tunnel
>> rds_rdma rds xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT
>> nf_reject_ipv4 nft_compat nft_chain_nat nf_nat nf_conntrack
>> nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink tun bridge stp llc
>> vfat fat rpcrdma sunrpc rdma_ucm ib_srpt ib_isert iscsi_target_mod
>> target_core_mod intel_rapl_msr intel_rapl_common ib_iser libiscsi
>> scsi_transport_iscsi rdma_cm ib_cm i10nm_edac iw_cm nfit libnvdimm
>> x86_pkg_temp_thermal intel_powerclamp coretemp ipmi_ssif kvm_intel kvm
>> irdma iTCO_wdt iTCO_vendor_support i40e irqbypass crct10dif_pclmul
>> crc32_pclmul ib_uverbs ghash_clmulni_intel rapl intel_cstate ib_core
>> intel_uncore wmi_bmof pcspkr mei_me isst_if_mbox_pci isst_if_mmio
>> acpi_ipmi isst_if_common ipmi_si i2c_i801 mei intel_pch_thermal
>> i2c_smbus ipmi_devintf ipmi_msghandler acpi_power_meter ip_tables xfs
>> libcrc32c sd_mod t10_pi crc64_rocksoft crc64 sg mgag200 i2c_algo_bit
>> drm_shmem_helper drm_kms_helper syscopyarea sysfillrect ice
>> kernel: sysimgblt fb_sys_fops ahci drm libahci crc32c_intel libata
>> megaraid_sas tg3 wmi dm_mirror dm_region_hash dm_log dm_mod fuse [last
>> unloaded: ip6_udp_tunnel]
>> kernel: CPU: 74 PID: 38510 Comm: rping Kdump: loaded Tainted: G S
>> W OE 5.18.0.RXE #14
>> kernel: Hardware name: Dell Inc. PowerEdge R750/06V45N, BIOS 1.2.4
>> 05/28/2021
>> kernel: RIP: 0010:rxe_responder+0x1d67/0x1dd0 [rdma_rxe]
>> kernel: Code: 24 30 48 89 44 24 30 49 8b 86 88 00 00 00 48 89 44 24
>> 38 48 8b 73 20 48 8b 43 18 ff d0 0f 1f 00 e9 10 e3 ff ff e8 e9 52 98
>> ee <0f> 0b 45 8b 86 f0 00 00 00 48 8b 8c 24 e0 00 00 00 ba 01 03 00 00
>> kernel: RSP: 0018:ff5f5b78c7624e70 EFLAGS: 00010246
>> kernel: RAX: ff20346c70a1d700 RBX: ff20346c7127c040 RCX:
>> ff20346c70a1d700
>> kernel: RDX: 0000000000000000 RSI: 0000000000000000 RDI:
>> ff20346c53194000
>> kernel: RBP: 0000000000000040 R08: 2ebbb556a556fe7f R09:
>> 69de575d0320dc48
>> kernel: R10: ff5f5b78c7624de0 R11: 00000000ee4984a4 R12:
>> ff20346c70a1d700
>> kernel: R13: 0000000000000000 R14: ff20346ef0539000 R15:
>> ff20346c70a1c528
>> kernel: FS: 00007ff34d49b740(0000) GS:ff20347b3fa80000(0000)
>> knlGS:0000000000000000
>> kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> kernel: CR2: 00007ff40be030c0 CR3: 00000003d0634005 CR4:
>> 0000000000771ee0
>> kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2:
>> 0000000000000000
>> kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
>> 0000000000000400
>> kernel: PKRU: 55555554
>> kernel: Call Trace:
>> kernel: <IRQ>
>> kernel: ? __local_bh_enable_ip+0x9f/0xe0
>> kernel: ? rxe_do_task+0x67/0xe0 [rdma_rxe]
>> kernel: ? __local_bh_enable_ip+0x77/0xe0
>> kernel: rxe_do_task+0x71/0xe0 [rdma_rxe]
>> kernel: tasklet_action_common.isra.15+0xb8/0xf0
>> kernel: __do_softirq+0xe4/0x48c
>> kernel: ? rxe_do_task+0x67/0xe0 [rdma_rxe]
>> kernel: do_softirq+0xb5/0x100
>> kernel: </IRQ>
>> kernel: <TASK>
>> kernel: __local_bh_enable_ip+0xd0/0xe0
>> kernel: rxe_do_task+0x67/0xe0 [rdma_rxe]
>> kernel: rxe_post_send+0x2ff/0x4c0 [rdma_rxe]
>> kernel: ? rdma_lookup_get_uobject+0x131/0x1e0 [ib_uverbs]
>> kernel: ib_uverbs_post_send+0x4d5/0x700 [ib_uverbs]
>> kernel: ib_uverbs_write+0x38f/0x5e0 [ib_uverbs]
>> kernel: ? find_held_lock+0x2d/0x90
>> kernel: vfs_write+0xb8/0x370
>> kernel: ksys_write+0xbb/0xd0
>> kernel: ? syscall_trace_enter.isra.15+0x169/0x220
>> kernel: do_syscall_64+0x37/0x80
>>
>> Zhu Yanjun
>>
>> in rxe_resp.c
>>> This could be caused by a race between shutting down the qp and finishing up an RDMA read.
>>> The responder resources state machine is completely unprotected from
>>> simultaneous access by verbs code and bh code in rxe_resp.c.
>>> rxe_resp is a tasklet so all the accesses from there are serialized
>>> but if anyone makes a verbs call that touches the responder resources it could cause problems. The most likely (only?) place this could happen is qp shutdown.
>>>
>>> Bob
>>>
>>>
>>>
>>> diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c
>>> b/drivers/infiniband/sw/rxe/rxe_mr.c
>>>
>>> index 60a31b718774..66184f5a4ddf 100644
>>>
>>> --- a/drivers/infiniband/sw/rxe/rxe_mr.c
>>>
>>> +++ b/drivers/infiniband/sw/rxe/rxe_mr.c
>>>
>>> @@ -489,6 +489,7 @@ int copy_data(
>>>
>>> if (bytes > 0) {
>>>
>>> iova = sge->addr + offset;
>>>
>>>
>>>
>>> + WARN_ON(!mr);
>>>
>>> err = rxe_mr_copy(mr, iova, addr, bytes,
>>> dir);
>>>
>>> if (err)
>>>
>>> goto err2;
>>>
>>> diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c
>>> b/drivers/infiniband/sw/rxe/rxe_resp.c
>>>
>>> index 1d95fab606da..6e3e86bdccd7 100644
>>>
>>> --- a/drivers/infiniband/sw/rxe/rxe_resp.c
>>>
>>> +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
>>>
>>> @@ -536,6 +536,7 @@ static enum resp_states write_data_in(struct
>>> rxe_qp *qp,
>>>
>>> int err;
>>>
>>> int data_len = payload_size(pkt);
>>>
>>>
>>>
>>> + WARN_ON(!qp->resp.mr);
>>>
>>> err = rxe_mr_copy(qp->resp.mr, qp->resp.va +
>>> qp->resp.offset,
>>>
>>> payload_addr(pkt), data_len,
>>> RXE_TO_MR_OBJ);
>>>
>>> if (err) {
>>>
>>> @@ -772,6 +773,7 @@ static enum resp_states read_reply(struct rxe_qp
>>> *qp,
>>>
>>> if (!skb)
>>>
>>> return RESPST_ERR_RNR;
>>>
>>>
>>>
>>> + WARN_ON(!mr);
>>>
>>> err = rxe_mr_copy(mr, res->read.va, payload_addr(&ack_pkt),
>>>
>>> payload, RXE_FROM_MR_OBJ);
>>>
>>> if (err)
>>>
When you run rping are you going between two machines? It doesn't work in loopback as far as I can tell.
Bob
