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dai index alignment #42

Merged
merged 2 commits into from
Jul 24, 2018
Merged

dai index alignment #42

merged 2 commits into from
Jul 24, 2018

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xiulipan
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@xiulipan xiulipan commented Jul 20, 2018 •
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DAI type and index will be used to get dai, make them be the same in
both sof_ipc_dai_config and sof_ipc_comp_dai.

Need topology patch to add DAI_INDEX alongside with all DAI_TYPE
thesofproject/soft#40

Will fix what lack form thesofproject/soft#33

@xiulipan xiulipan mentioned this pull request Jul 20, 2018
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plbossart
plbossart reviewed Jul 20, 2018
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Sorry, I don't understand this change. Currently we are using standard ALSA/ASoC hooks to get the ID, why would we want to have a custom token we we already have standard one? Not to mention that we will break all existing topology files?
@ranj063 and @lgirdwood, what do you think?

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ranj063 commented Jul 20, 2018

@plbossart @xiulipan this one doesnt look very straightforward to understand. Let me take a deeper look and will post comments later.

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@plbossart
This is not the standard ID. I just changed the DAI type and index we used to get the dai in our firmware.
This change is to make an alignment for two usage.
Please see more analysis in thesofproject/soft#33

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ranj063 commented Jul 23, 2018 •
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@plbossart @xiulipan the intention is correct here.

In the firmware, we acquire a platform DAI based on its type and its index in the platform dai array. The ssp and dmic dai's are defined in separate arrays with their respective indices starting at 0. Therefore, this index information needs to be passed from the topology while creating a new comp_dai or setting the config for a dai. Earlier, when we only had one DAI in the topology, we always acquired the DAI from either the SSP array or the DMIC array with index 0 and it all worked fine. But with multiple dai's in topology, we're going to have to pass this information explicitly. This is required because the id is unique irrespective of dai type and it increments from 0 for all successive dai's in topology. Whereas the dai_index restarts at 0 for each dai type.

I have just discussed the changes with Xiuli and he will refine the patch to add the dai_index to the ipc structure for comp_dai and config.

xiulipan added 2 commits July 23, 2018 16:39
@xiulipan
[SQUASHME]ASoC: SOF: uapi: ipc: refine dai index name
7f4d9fa 
In sof_ipc_dai_config and sof_ipc_dai_config we both need DAI type and
index. Make the field name same and clear.

Signed-off-by: Pan Xiuli <[email protected]>
@xiulipan
[SQUASHME]ASoC: SOF: topology : align dai type and index in topology …
fe9c440 
…parse

DAI type and index will be used to dai_get function in FW, make both
sof_ipc_dai_config and sof_ipc_comp_dai use the same index and type.

Signed-off-by: Pan Xiuli <[email protected]>
@xiulipan xiulipan changed the title [SQUASHME]ASoC: SOF: topology : align dai type and id in topology parse dai index alignment Jul 23, 2018
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@plbossart @lgirdwood
Add structure filed modify first to make naming alignment.
Also find we lack some token in topology that is needed to find the dai thesofproject/soft#40

This will solve the multiple type dais support problem. We also need take care of how to use id and index in topology. Some index or id is not important, but some is very critical for binding.

@xiulipan xiulipan mentioned this pull request Jul 23, 2018
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plbossart
plbossart reviewed Jul 23, 2018
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sound/soc/sof/topology.c
@@ -1720,7 +1722,6 @@ static int sof_link_load(struct snd_soc_component *scomp, int index,
hw_config = &cfg->hw_config[0];

config.hdr.cmd = SOF_IPC_GLB_DAI_MSG | SOF_IPC_DAI_CONFIG;
config.id = le32_to_cpu(hw_config->id);
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can you clarify if config.id is no longer used at all?
I would like to understand how the matching with the machine driver is done, we are using a .index field in the BE definitions and I can't connect the dots with this patch. Are we saying there is an absolute index for all BEs/DAI, and then a relative one for each DAI type?

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@plbossart
This filed should be naming as index.
The backend dai here is for firmware only, why should be handle with machine driver?
All these filed I change is only topology vendor data used for IPC binding and Firmware DAI finding.

These Index is none related with BEs/DAI.

My first patch is to change the name for all structure.
Could you have a look at thesofproject/sof#140
to see what this name changing will influence the firmware side

Actually I was confused by all these id and index in topology, I can see we have some id = index or index = id code in kernel. So I take @ranj063 suggestion to rename the filed to be dai_index to make it to be the SOF_TKN_DAI_INDEX value

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Let me try:
The firmware only needs to know about the dai_index (relative to the daI_type). The machine driver and BE matching only care about the dai_link index (which is absolute/linear across all DAI types). The topology provides both dai_index and link_index.

is this what you are trying to say?

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@plbossart a minor correction in your statement:

"The firmware only needs to know about the dai_index (relative to the daI_type). The machine driver and BE matching only care about the dai_link ID (which is absolute/linear across all DAI types ). The topology provides both dai_index and link_ID."

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I call it ID because it doesnt necessarily have to be linear although a linear progression in the machine driver would be nice to have.

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@plbossart
actually I still did not get what id and index in what Section is useful in topology.
We will find more cases to make these filed useful.

The id in SectionBE used to be set to be 0 for all topology, but later we find it will be useful if there are too many BE DAIs.

So in this PR, we find more id and index naming issue. We need to have a clean up about naming first. Misuse name will make people confusing even when try to explain things.

@plbossart plbossart merged commit 46b7b64 into thesofproject:topic/sof-dev Jul 24, 2018
plbossart pushed a commit that referenced this pull request Dec 11, 2018
@selvintxavier @jgunthorpe
RDMA/bnxt_re: Fix system hang when registration with L2 driver fails
3c4b141 
Driver doesn't release rtnl lock if registration with
L2 driver (bnxt_re_register_netdev) fais and this causes
hang while requesting for the next lock.

[  371.635416] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  371.635417] kworker/u48:1   D    0   634      2 0x80000000
[  371.635423] Workqueue: bnxt_re bnxt_re_task [bnxt_re]
[  371.635424] Call Trace:
[  371.635426]  ? __schedule+0x36b/0xbd0
[  371.635429]  schedule+0x39/0x90
[  371.635430]  schedule_preempt_disabled+0x11/0x20
[  371.635431]  __mutex_lock+0x45b/0x9c0
[  371.635433]  ? __mutex_lock+0x16d/0x9c0
[  371.635435]  ? bnxt_re_ib_reg+0x2b/0xb30 [bnxt_re]
[  371.635438]  ? wake_up_klogd+0x37/0x40
[  371.635442]  bnxt_re_ib_reg+0x2b/0xb30 [bnxt_re]
[  371.635447]  bnxt_re_task+0xfd/0x180 [bnxt_re]
[  371.635449]  process_one_work+0x216/0x5b0
[  371.635450]  ? process_one_work+0x189/0x5b0
[  371.635453]  worker_thread+0x4e/0x3d0
[  371.635455]  kthread+0x10e/0x140
[  371.635456]  ? process_one_work+0x5b0/0x5b0
[  371.635458]  ? kthread_stop+0x220/0x220
[  371.635460]  ret_from_fork+0x3a/0x50
[  371.635477] INFO: task NetworkManager:1228 blocked for more than 120 seconds.
[  371.635478]       Tainted: G    B      OE     4.20.0-rc1+ #42
[  371.635479] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

Release the rtnl_lock correctly in the failure path.

Fixes: de5c95d ("RDMA/bnxt_re: Fix system crash during RDMA resource initialization")
Signed-off-by: Selvin Xavier <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
plbossart pushed a commit that referenced this pull request Dec 11, 2018
@selvintxavier @jgunthorpe
RDMA/bnxt_re: Avoid accessing the device structure after it is freed
a6c66d6 
When bnxt_re_ib_reg returns failure, the device structure gets
freed. Driver tries to access the device pointer
after it is freed.

[ 4871.034744] Failed to register with netedev: 0xffffffa1
[ 4871.034765] infiniband (null): Failed to register with IB: 0xffffffea
[ 4871.046430] ==================================================================
[ 4871.046437] BUG: KASAN: use-after-free in bnxt_re_task+0x63/0x180 [bnxt_re]
[ 4871.046439] Write of size 4 at addr ffff880fa8406f48 by task kworker/u48:2/17813

[ 4871.046443] CPU: 20 PID: 17813 Comm: kworker/u48:2 Kdump: loaded Tainted: G B OE  4.20.0-rc1+ #42
[ 4871.046444] Hardware name: Dell Inc. PowerEdge R730/0599V5, BIOS 1.0.4 08/28/2014
[ 4871.046447] Workqueue: bnxt_re bnxt_re_task [bnxt_re]
[ 4871.046449] Call Trace:
[ 4871.046454]  dump_stack+0x91/0xeb
[ 4871.046458]  print_address_description+0x6a/0x2a0
[ 4871.046461]  kasan_report+0x176/0x2d0
[ 4871.046463]  ? bnxt_re_task+0x63/0x180 [bnxt_re]
[ 4871.046466]  bnxt_re_task+0x63/0x180 [bnxt_re]
[ 4871.046470]  process_one_work+0x216/0x5b0
[ 4871.046471]  ? process_one_work+0x189/0x5b0
[ 4871.046475]  worker_thread+0x4e/0x3d0
[ 4871.046479]  kthread+0x10e/0x140
[ 4871.046480]  ? process_one_work+0x5b0/0x5b0
[ 4871.046482]  ? kthread_stop+0x220/0x220
[ 4871.046486]  ret_from_fork+0x3a/0x50

[ 4871.046492] The buggy address belongs to the page:
[ 4871.046494] page:ffffea003ea10180 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[ 4871.046495] flags: 0x57ffffc0000000()
[ 4871.046498] raw: 0057ffffc0000000 0000000000000000 ffffea003ea10188 0000000000000000
[ 4871.046500] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[ 4871.046501] page dumped because: kasan: bad access detected

Avoid accessing the device structure once it is freed.

Fixes: 497158a ("RDMA/bnxt_re: Fix the ib_reg failure cleanup")
Signed-off-by: Selvin Xavier <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
plbossart pushed a commit that referenced this pull request Dec 11, 2018
@davem330
tipc: fix lockdep warning during node delete
ec835f8 
We see the following lockdep warning:

[ 2284.078521] ======================================================
[ 2284.078604] WARNING: possible circular locking dependency detected
[ 2284.078604] 4.19.0+ #42 Tainted: G            E
[ 2284.078604] ------------------------------------------------------
[ 2284.078604] rmmod/254 is trying to acquire lock:
[ 2284.078604] 00000000acd94e28 ((&n->timer)#2){+.-.}, at: del_timer_sync+0x5/0xa0
[ 2284.078604]
[ 2284.078604] but task is already holding lock:
[ 2284.078604] 00000000f997afc0 (&(&tn->node_list_lock)->rlock){+.-.}, at: tipc_node_stop+0xac/0x190 [tipc]
[ 2284.078604]
[ 2284.078604] which lock already depends on the new lock.
[ 2284.078604]
[ 2284.078604]
[ 2284.078604] the existing dependency chain (in reverse order) is:
[ 2284.078604]
[ 2284.078604] -> #1 (&(&tn->node_list_lock)->rlock){+.-.}:
[ 2284.078604]        tipc_node_timeout+0x20a/0x330 [tipc]
[ 2284.078604]        call_timer_fn+0xa1/0x280
[ 2284.078604]        run_timer_softirq+0x1f2/0x4d0
[ 2284.078604]        __do_softirq+0xfc/0x413
[ 2284.078604]        irq_exit+0xb5/0xc0
[ 2284.078604]        smp_apic_timer_interrupt+0xac/0x210
[ 2284.078604]        apic_timer_interrupt+0xf/0x20
[ 2284.078604]        default_idle+0x1c/0x140
[ 2284.078604]        do_idle+0x1bc/0x280
[ 2284.078604]        cpu_startup_entry+0x19/0x20
[ 2284.078604]        start_secondary+0x187/0x1c0
[ 2284.078604]        secondary_startup_64+0xa4/0xb0
[ 2284.078604]
[ 2284.078604] -> #0 ((&n->timer)#2){+.-.}:
[ 2284.078604]        del_timer_sync+0x34/0xa0
[ 2284.078604]        tipc_node_delete+0x1a/0x40 [tipc]
[ 2284.078604]        tipc_node_stop+0xcb/0x190 [tipc]
[ 2284.078604]        tipc_net_stop+0x154/0x170 [tipc]
[ 2284.078604]        tipc_exit_net+0x16/0x30 [tipc]
[ 2284.078604]        ops_exit_list.isra.8+0x36/0x70
[ 2284.078604]        unregister_pernet_operations+0x87/0xd0
[ 2284.078604]        unregister_pernet_subsys+0x1d/0x30
[ 2284.078604]        tipc_exit+0x11/0x6f2 [tipc]
[ 2284.078604]        __x64_sys_delete_module+0x1df/0x240
[ 2284.078604]        do_syscall_64+0x66/0x460
[ 2284.078604]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 2284.078604]
[ 2284.078604] other info that might help us debug this:
[ 2284.078604]
[ 2284.078604]  Possible unsafe locking scenario:
[ 2284.078604]
[ 2284.078604]        CPU0                    CPU1
[ 2284.078604]        ----                    ----
[ 2284.078604]   lock(&(&tn->node_list_lock)->rlock);
[ 2284.078604]                                lock((&n->timer)#2);
[ 2284.078604]                                lock(&(&tn->node_list_lock)->rlock);
[ 2284.078604]   lock((&n->timer)#2);
[ 2284.078604]
[ 2284.078604]  *** DEADLOCK ***
[ 2284.078604]
[ 2284.078604] 3 locks held by rmmod/254:
[ 2284.078604]  #0: 000000003368be9b (pernet_ops_rwsem){+.+.}, at: unregister_pernet_subsys+0x15/0x30
[ 2284.078604]  #1: 0000000046ed9c86 (rtnl_mutex){+.+.}, at: tipc_net_stop+0x144/0x170 [tipc]
[ 2284.078604]  #2: 00000000f997afc0 (&(&tn->node_list_lock)->rlock){+.-.}, at: tipc_node_stop+0xac/0x19
[...}

The reason is that the node timer handler sometimes needs to delete a
node which has been disconnected for too long. To do this, it grabs
the lock 'node_list_lock', which may at the same time be held by the
generic node cleanup function, tipc_node_stop(), during module removal.
Since the latter is calling del_timer_sync() inside the same lock, we
have a potential deadlock.

We fix this letting the timer cleanup function use spin_trylock()
instead of just spin_lock(), and when it fails to grab the lock it
just returns so that the timer handler can terminate its execution.
This is safe to do, since tipc_node_stop() anyway is about to
delete both the timer and the node instance.

Fixes: 6a939f3 ("tipc: Auto removal of peer down node instance")
Acked-by: Ying Xue <[email protected]>
Signed-off-by: Jon Maloy <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
plbossart pushed a commit that referenced this pull request Jun 7, 2019
@paulusmack
KVM: PPC: Book3S HV: Fix lockdep warning when entering guest on POWER9
1b28d55 
Commit 3309bec ("KVM: PPC: Book3S HV: Fix lockdep warning when
entering the guest") moved calls to trace_hardirqs_{on,off} in the
entry path used for HPT guests.  Similar code exists in the new
streamlined entry path used for radix guests on POWER9.  This makes
the same change there, so as to avoid lockdep warnings such as this:

[  228.686461] DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)
[  228.686480] WARNING: CPU: 116 PID: 3803 at ../kernel/locking/lockdep.c:4219 check_flags.part.23+0x21c/0x270
[  228.686544] Modules linked in: vhost_net vhost xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat
+xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter
+ebtables ip6table_filter ip6_tables iptable_filter fuse kvm_hv kvm at24 ipmi_powernv regmap_i2c ipmi_devintf
+uio_pdrv_genirq ofpart ipmi_msghandler uio powernv_flash mtd ibmpowernv opal_prd ip_tables ext4 mbcache jbd2 btrfs
+zstd_decompress zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx libcrc32c xor
+raid6_pq raid1 raid0 ses sd_mod enclosure scsi_transport_sas ast i2c_opal i2c_algo_bit drm_kms_helper syscopyarea
+sysfillrect sysimgblt fb_sys_fops ttm drm i40e e1000e cxl aacraid tg3 drm_panel_orientation_quirks i2c_core
[  228.686859] CPU: 116 PID: 3803 Comm: qemu-system-ppc Kdump: loaded Not tainted 5.2.0-rc1-xive+ #42
[  228.686911] NIP:  c0000000001b394c LR: c0000000001b3948 CTR: c000000000bfad20
[  228.686963] REGS: c000200cdb50f570 TRAP: 0700   Not tainted  (5.2.0-rc1-xive+)
[  228.687001] MSR:  9000000002823033 <SF,HV,VEC,VSX,FP,ME,IR,DR,RI,LE>  CR: 48222222  XER: 20040000
[  228.687060] CFAR: c000000000116db0 IRQMASK: 1
[  228.687060] GPR00: c0000000001b3948 c000200cdb50f800 c0000000015e7600 000000000000002e
[  228.687060] GPR04: 0000000000000001 c0000000001c71a0 000000006e655f73 72727563284e4f5f
[  228.687060] GPR08: 0000200e60680000 0000000000000000 c000200cdb486180 0000000000000000
[  228.687060] GPR12: 0000000000002000 c000200fff61a680 0000000000000000 00007fffb75c0000
[  228.687060] GPR16: 0000000000000000 0000000000000000 c0000000017d6900 c000000001124900
[  228.687060] GPR20: 0000000000000074 c008000006916f68 0000000000000074 0000000000000074
[  228.687060] GPR24: ffffffffffffffff ffffffffffffffff 0000000000000003 c000200d4b600000
[  228.687060] GPR28: c000000001627e58 c000000001489908 c000000001627e58 c000000002304de0
[  228.687377] NIP [c0000000001b394c] check_flags.part.23+0x21c/0x270
[  228.687415] LR [c0000000001b3948] check_flags.part.23+0x218/0x270
[  228.687466] Call Trace:
[  228.687488] [c000200cdb50f800] [c0000000001b3948] check_flags.part.23+0x218/0x270 (unreliable)
[  228.687542] [c000200cdb50f870] [c0000000001b6548] lock_is_held_type+0x188/0x1c0
[  228.687595] [c000200cdb50f8d0] [c0000000001d939c] rcu_read_lock_sched_held+0xdc/0x100
[  228.687646] [c000200cdb50f900] [c0000000001dd704] rcu_note_context_switch+0x304/0x340
[  228.687701] [c000200cdb50f940] [c0080000068fcc58] kvmhv_run_single_vcpu+0xdb0/0x1120 [kvm_hv]
[  228.687756] [c000200cdb50fa20] [c0080000068fd5b0] kvmppc_vcpu_run_hv+0x5e8/0xe40 [kvm_hv]
[  228.687816] [c000200cdb50faf0] [c0080000071797dc] kvmppc_vcpu_run+0x34/0x48 [kvm]
[  228.687863] [c000200cdb50fb10] [c0080000071755dc] kvm_arch_vcpu_ioctl_run+0x244/0x420 [kvm]
[  228.687916] [c000200cdb50fba0] [c008000007165ccc] kvm_vcpu_ioctl+0x424/0x838 [kvm]
[  228.687957] [c000200cdb50fd10] [c000000000433a24] do_vfs_ioctl+0xd4/0xcd0
[  228.687995] [c000200cdb50fdb0] [c000000000434724] ksys_ioctl+0x104/0x120
[  228.688033] [c000200cdb50fe00] [c000000000434768] sys_ioctl+0x28/0x80
[  228.688072] [c000200cdb50fe20] [c00000000000b888] system_call+0x5c/0x70
[  228.688109] Instruction dump:
[  228.688142] 4bf6342d 60000000 0fe00000 e8010080 7c0803a6 4bfffe60 3c82ff87 3c62ff87
[  228.688196] 388472d0 3863d738 4bf63405 60000000 <0fe00000> 4bffff4c 3c82ff87 3c62ff87
[  228.688251] irq event stamp: 205
[  228.688287] hardirqs last  enabled at (205): [<c0080000068fc1b4>] kvmhv_run_single_vcpu+0x30c/0x1120 [kvm_hv]
[  228.688344] hardirqs last disabled at (204): [<c0080000068fbff0>] kvmhv_run_single_vcpu+0x148/0x1120 [kvm_hv]
[  228.688412] softirqs last  enabled at (180): [<c000000000c0b2ac>] __do_softirq+0x4ac/0x5d4
[  228.688464] softirqs last disabled at (169): [<c000000000122aa8>] irq_exit+0x1f8/0x210
[  228.688513] ---[ end trace eb16f6260022a812 ]---
[  228.688548] possible reason: unannotated irqs-off.
[  228.688571] irq event stamp: 205
[  228.688607] hardirqs last  enabled at (205): [<c0080000068fc1b4>] kvmhv_run_single_vcpu+0x30c/0x1120 [kvm_hv]
[  228.688664] hardirqs last disabled at (204): [<c0080000068fbff0>] kvmhv_run_single_vcpu+0x148/0x1120 [kvm_hv]
[  228.688719] softirqs last  enabled at (180): [<c000000000c0b2ac>] __do_softirq+0x4ac/0x5d4
[  228.688758] softirqs last disabled at (169): [<c000000000122aa8>] irq_exit+0x1f8/0x210

Cc: [email protected] # v4.20+
Fixes: 95a6432 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests")
Signed-off-by: Paul Mackerras <[email protected]>
Reviewed-by: Cédric Le Goater <[email protected]>
Tested-by: Cédric Le Goater <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
bardliao pushed a commit that referenced this pull request Jun 11, 2019
@jsitnicki
bpf: Stop the psock parser before canceling its work
083b6a3 
BugLink: https://bugs.launchpad.net/bugs/1820318

commit e8e3437 upstream.

We might have never enabled (started) the psock's parser, in which case it
will not get stopped when destroying the psock. This leads to a warning
when trying to cancel parser's work from psock's deferred destructor:

[  405.325769] WARNING: CPU: 1 PID: 3216 at net/strparser/strparser.c:526 strp_done+0x3c/0x40
[  405.326712] Modules linked in: [last unloaded: test_bpf]
[  405.327359] CPU: 1 PID: 3216 Comm: kworker/1:164 Tainted: G        W         5.0.0 #42
[  405.328294] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20180531_142017-buildhw-08.phx2.fedoraproject.org-1.fc28 04/01/2014
[  405.329712] Workqueue: events sk_psock_destroy_deferred
[  405.330254] RIP: 0010:strp_done+0x3c/0x40
[  405.330706] Code: 28 e8 b8 d5 6b ff 48 8d bb 80 00 00 00 e8 9c d5 6b ff 48 8b 7b 18 48 85 ff 74 0d e8 1e a5 e8 ff 48 c7 43 18 00 00 00 00 5b c3 <0f> 0b eb cf 66 66 66 66 90 55 89 f5 53 48 89 fb 48 83 c7 28 e8 0b
[  405.332862] RSP: 0018:ffffc900026bbe50 EFLAGS: 00010246
[  405.333482] RAX: ffffffff819323e0 RBX: ffff88812cb83640 RCX: ffff88812cb829e8
[  405.334228] RDX: 0000000000000001 RSI: ffff88812cb837e8 RDI: ffff88812cb83640
[  405.335366] RBP: ffff88813fd22680 R08: 0000000000000000 R09: 000073746e657665
[  405.336472] R10: 8080808080808080 R11: 0000000000000001 R12: ffff88812cb83600
[  405.337760] R13: 0000000000000000 R14: ffff88811f401780 R15: ffff88812cb837e8
[  405.338777] FS:  0000000000000000(0000) GS:ffff88813fd00000(0000) knlGS:0000000000000000
[  405.339903] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  405.340821] CR2: 00007fb11489a6b8 CR3: 000000012d4d6000 CR4: 00000000000406e0
[  405.341981] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  405.343131] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  405.344415] Call Trace:
[  405.344821]  sk_psock_destroy_deferred+0x23/0x1b0
[  405.345585]  process_one_work+0x1ae/0x3e0
[  405.346110]  worker_thread+0x3c/0x3b0
[  405.346576]  ? pwq_unbound_release_workfn+0xd0/0xd0
[  405.347187]  kthread+0x11d/0x140
[  405.347601]  ? __kthread_parkme+0x80/0x80
[  405.348108]  ret_from_fork+0x35/0x40
[  405.348566] ---[ end trace a4a3af4026a327d4 ]---

Stop psock's parser just before canceling its work.

Fixes: 1d79895 ("sk_msg: Always cancel strp work before freeing the psock")
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Jakub Sitnicki <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
plbossart pushed a commit that referenced this pull request Aug 21, 2019
@sagigrimberg
nvme: fix a possible deadlock when passthru commands sent to a multip…
b9156da 
…ath device

When the user issues a command with side effects, we will end up freezing
the namespace request queue when updating disk info (and the same for
the corresponding mpath disk node).

However, we are not freezing the mpath node request queue,
which means that mpath I/O can still come in and block on blk_queue_enter
(called from nvme_ns_head_make_request -> direct_make_request).

This is a deadlock, because blk_queue_enter will block until the inner
namespace request queue is unfroze, but that process is blocked because
the namespace revalidation is trying to update the mpath disk info
and freeze its request queue (which will never complete because
of the I/O that is blocked on blk_queue_enter).

Fix this by freezing all the subsystem nsheads request queues before
executing the passthru command. Given that these commands are infrequent
we should not worry about this temporary I/O freeze to keep things sane.

Here is the matching hang traces:
--
[ 374.465002] INFO: task systemd-udevd:17994 blocked for more than 122 seconds.
[ 374.472975] Not tainted 5.2.0-rc3-mpdebug+ #42
[ 374.478522] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 374.487274] systemd-udevd D 0 17994 1 0x00000000
[ 374.493407] Call Trace:
[ 374.496145] __schedule+0x2ef/0x620
[ 374.500047] schedule+0x38/0xa0
[ 374.503569] blk_queue_enter+0x139/0x220
[ 374.507959] ? remove_wait_queue+0x60/0x60
[ 374.512540] direct_make_request+0x60/0x130
[ 374.517219] nvme_ns_head_make_request+0x11d/0x420 [nvme_core]
[ 374.523740] ? generic_make_request_checks+0x307/0x6f0
[ 374.529484] generic_make_request+0x10d/0x2e0
[ 374.534356] submit_bio+0x75/0x140
[ 374.538163] ? guard_bio_eod+0x32/0xe0
[ 374.542361] submit_bh_wbc+0x171/0x1b0
[ 374.546553] block_read_full_page+0x1ed/0x330
[ 374.551426] ? check_disk_change+0x70/0x70
[ 374.556008] ? scan_shadow_nodes+0x30/0x30
[ 374.560588] blkdev_readpage+0x18/0x20
[ 374.564783] do_read_cache_page+0x301/0x860
[ 374.569463] ? blkdev_writepages+0x10/0x10
[ 374.574037] ? prep_new_page+0x88/0x130
[ 374.578329] ? get_page_from_freelist+0xa2f/0x1280
[ 374.583688] ? __alloc_pages_nodemask+0x179/0x320
[ 374.588947] read_cache_page+0x12/0x20
[ 374.593142] read_dev_sector+0x2d/0xd0
[ 374.597337] read_lba+0x104/0x1f0
[ 374.601046] find_valid_gpt+0xfa/0x720
[ 374.605243] ? string_nocheck+0x58/0x70
[ 374.609534] ? find_valid_gpt+0x720/0x720
[ 374.614016] efi_partition+0x89/0x430
[ 374.618113] ? string+0x48/0x60
[ 374.621632] ? snprintf+0x49/0x70
[ 374.625339] ? find_valid_gpt+0x720/0x720
[ 374.629828] check_partition+0x116/0x210
[ 374.634214] rescan_partitions+0xb6/0x360
[ 374.638699] __blkdev_reread_part+0x64/0x70
[ 374.643377] blkdev_reread_part+0x23/0x40
[ 374.647860] blkdev_ioctl+0x48c/0x990
[ 374.651956] block_ioctl+0x41/0x50
[ 374.655766] do_vfs_ioctl+0xa7/0x600
[ 374.659766] ? locks_lock_inode_wait+0xb1/0x150
[ 374.664832] ksys_ioctl+0x67/0x90
[ 374.668539] __x64_sys_ioctl+0x1a/0x20
[ 374.672732] do_syscall_64+0x5a/0x1c0
[ 374.676828] entry_SYSCALL_64_after_hwframe+0x44/0xa9

[ 374.738474] INFO: task nvmeadm:49141 blocked for more than 123 seconds.
[ 374.745871] Not tainted 5.2.0-rc3-mpdebug+ #42
[ 374.751419] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 374.760170] nvmeadm D 0 49141 36333 0x00004080
[ 374.766301] Call Trace:
[ 374.769038] __schedule+0x2ef/0x620
[ 374.772939] schedule+0x38/0xa0
[ 374.776452] blk_mq_freeze_queue_wait+0x59/0x100
[ 374.781614] ? remove_wait_queue+0x60/0x60
[ 374.786192] blk_mq_freeze_queue+0x1a/0x20
[ 374.790773] nvme_update_disk_info.isra.57+0x5f/0x350 [nvme_core]
[ 374.797582] ? nvme_identify_ns.isra.50+0x71/0xc0 [nvme_core]
[ 374.804006] __nvme_revalidate_disk+0xe5/0x110 [nvme_core]
[ 374.810139] nvme_revalidate_disk+0xa6/0x120 [nvme_core]
[ 374.816078] ? nvme_submit_user_cmd+0x11e/0x320 [nvme_core]
[ 374.822299] nvme_user_cmd+0x264/0x370 [nvme_core]
[ 374.827661] nvme_dev_ioctl+0x112/0x1d0 [nvme_core]
[ 374.833114] do_vfs_ioctl+0xa7/0x600
[ 374.837117] ? __audit_syscall_entry+0xdd/0x130
[ 374.842184] ksys_ioctl+0x67/0x90
[ 374.845891] __x64_sys_ioctl+0x1a/0x20
[ 374.850082] do_syscall_64+0x5a/0x1c0
[ 374.854178] entry_SYSCALL_64_after_hwframe+0x44/0xa9
--

Reported-by: James Puthukattukaran <[email protected]>
Tested-by: James Puthukattukaran <[email protected]>
Reviewed-by: Keith Busch <[email protected]>
Signed-off-by: Sagi Grimberg <[email protected]>
shumingfan pushed a commit to shumingfan/linux that referenced this pull request Aug 23, 2019
@sagigrimberg @shumingfan
nvme: fix a possible deadlock when passthru commands sent to a multip…
4117e12 
…ath device

When the user issues a command with side effects, we will end up freezing
the namespace request queue when updating disk info (and the same for
the corresponding mpath disk node).

However, we are not freezing the mpath node request queue,
which means that mpath I/O can still come in and block on blk_queue_enter
(called from nvme_ns_head_make_request -> direct_make_request).

This is a deadlock, because blk_queue_enter will block until the inner
namespace request queue is unfroze, but that process is blocked because
the namespace revalidation is trying to update the mpath disk info
and freeze its request queue (which will never complete because
of the I/O that is blocked on blk_queue_enter).

Fix this by freezing all the subsystem nsheads request queues before
executing the passthru command. Given that these commands are infrequent
we should not worry about this temporary I/O freeze to keep things sane.

Here is the matching hang traces:
--
[ 374.465002] INFO: task systemd-udevd:17994 blocked for more than 122 seconds.
[ 374.472975] Not tainted 5.2.0-rc3-mpdebug+ thesofproject#42
[ 374.478522] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 374.487274] systemd-udevd D 0 17994 1 0x00000000
[ 374.493407] Call Trace:
[ 374.496145] __schedule+0x2ef/0x620
[ 374.500047] schedule+0x38/0xa0
[ 374.503569] blk_queue_enter+0x139/0x220
[ 374.507959] ? remove_wait_queue+0x60/0x60
[ 374.512540] direct_make_request+0x60/0x130
[ 374.517219] nvme_ns_head_make_request+0x11d/0x420 [nvme_core]
[ 374.523740] ? generic_make_request_checks+0x307/0x6f0
[ 374.529484] generic_make_request+0x10d/0x2e0
[ 374.534356] submit_bio+0x75/0x140
[ 374.538163] ? guard_bio_eod+0x32/0xe0
[ 374.542361] submit_bh_wbc+0x171/0x1b0
[ 374.546553] block_read_full_page+0x1ed/0x330
[ 374.551426] ? check_disk_change+0x70/0x70
[ 374.556008] ? scan_shadow_nodes+0x30/0x30
[ 374.560588] blkdev_readpage+0x18/0x20
[ 374.564783] do_read_cache_page+0x301/0x860
[ 374.569463] ? blkdev_writepages+0x10/0x10
[ 374.574037] ? prep_new_page+0x88/0x130
[ 374.578329] ? get_page_from_freelist+0xa2f/0x1280
[ 374.583688] ? __alloc_pages_nodemask+0x179/0x320
[ 374.588947] read_cache_page+0x12/0x20
[ 374.593142] read_dev_sector+0x2d/0xd0
[ 374.597337] read_lba+0x104/0x1f0
[ 374.601046] find_valid_gpt+0xfa/0x720
[ 374.605243] ? string_nocheck+0x58/0x70
[ 374.609534] ? find_valid_gpt+0x720/0x720
[ 374.614016] efi_partition+0x89/0x430
[ 374.618113] ? string+0x48/0x60
[ 374.621632] ? snprintf+0x49/0x70
[ 374.625339] ? find_valid_gpt+0x720/0x720
[ 374.629828] check_partition+0x116/0x210
[ 374.634214] rescan_partitions+0xb6/0x360
[ 374.638699] __blkdev_reread_part+0x64/0x70
[ 374.643377] blkdev_reread_part+0x23/0x40
[ 374.647860] blkdev_ioctl+0x48c/0x990
[ 374.651956] block_ioctl+0x41/0x50
[ 374.655766] do_vfs_ioctl+0xa7/0x600
[ 374.659766] ? locks_lock_inode_wait+0xb1/0x150
[ 374.664832] ksys_ioctl+0x67/0x90
[ 374.668539] __x64_sys_ioctl+0x1a/0x20
[ 374.672732] do_syscall_64+0x5a/0x1c0
[ 374.676828] entry_SYSCALL_64_after_hwframe+0x44/0xa9

[ 374.738474] INFO: task nvmeadm:49141 blocked for more than 123 seconds.
[ 374.745871] Not tainted 5.2.0-rc3-mpdebug+ thesofproject#42
[ 374.751419] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 374.760170] nvmeadm D 0 49141 36333 0x00004080
[ 374.766301] Call Trace:
[ 374.769038] __schedule+0x2ef/0x620
[ 374.772939] schedule+0x38/0xa0
[ 374.776452] blk_mq_freeze_queue_wait+0x59/0x100
[ 374.781614] ? remove_wait_queue+0x60/0x60
[ 374.786192] blk_mq_freeze_queue+0x1a/0x20
[ 374.790773] nvme_update_disk_info.isra.57+0x5f/0x350 [nvme_core]
[ 374.797582] ? nvme_identify_ns.isra.50+0x71/0xc0 [nvme_core]
[ 374.804006] __nvme_revalidate_disk+0xe5/0x110 [nvme_core]
[ 374.810139] nvme_revalidate_disk+0xa6/0x120 [nvme_core]
[ 374.816078] ? nvme_submit_user_cmd+0x11e/0x320 [nvme_core]
[ 374.822299] nvme_user_cmd+0x264/0x370 [nvme_core]
[ 374.827661] nvme_dev_ioctl+0x112/0x1d0 [nvme_core]
[ 374.833114] do_vfs_ioctl+0xa7/0x600
[ 374.837117] ? __audit_syscall_entry+0xdd/0x130
[ 374.842184] ksys_ioctl+0x67/0x90
[ 374.845891] __x64_sys_ioctl+0x1a/0x20
[ 374.850082] do_syscall_64+0x5a/0x1c0
[ 374.854178] entry_SYSCALL_64_after_hwframe+0x44/0xa9
--

Reported-by: James Puthukattukaran <[email protected]>
Tested-by: James Puthukattukaran <[email protected]>
Reviewed-by: Keith Busch <[email protected]>
Signed-off-by: Sagi Grimberg <[email protected]>
dragosht pushed a commit to dragosht/linux-sof that referenced this pull request Oct 10, 2019
@torvalds
memcg, kmem: do not fail __GFP_NOFAIL charges
e55d9d9 
Thomas has noticed the following NULL ptr dereference when using cgroup
v1 kmem limit:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
PGD 0
P4D 0
Oops: 0000 [thesofproject#1] PREEMPT SMP PTI
CPU: 3 PID: 16923 Comm: gtk-update-icon Not tainted 4.19.51 thesofproject#42
Hardware name: Gigabyte Technology Co., Ltd. Z97X-Gaming G1/Z97X-Gaming G1, BIOS F9 07/31/2015
RIP: 0010:create_empty_buffers+0x24/0x100
Code: cd 0f 1f 44 00 00 0f 1f 44 00 00 41 54 49 89 d4 ba 01 00 00 00 55 53 48 89 fb e8 97 fe ff ff 48 89 c5 48 89 c2 eb 03 48 89 ca <48> 8b 4a 08 4c 09 22 48 85 c9 75 f1 48 89 6a 08 48 8b 43 18 48 8d
RSP: 0018:ffff927ac1b37bf8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: fffff2d4429fd740 RCX: 0000000100097149
RDX: 0000000000000000 RSI: 0000000000000082 RDI: ffff9075a99fbe00
RBP: 0000000000000000 R08: fffff2d440949cc8 R09: 00000000000960c0
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
R13: ffff907601f18360 R14: 0000000000002000 R15: 0000000000001000
FS:  00007fb55b288bc0(0000) GS:ffff90761f8c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000007aebc002 CR4: 00000000001606e0
Call Trace:
 create_page_buffers+0x4d/0x60
 __block_write_begin_int+0x8e/0x5a0
 ? ext4_inode_attach_jinode.part.82+0xb0/0xb0
 ? jbd2__journal_start+0xd7/0x1f0
 ext4_da_write_begin+0x112/0x3d0
 generic_perform_write+0xf1/0x1b0
 ? file_update_time+0x70/0x140
 __generic_file_write_iter+0x141/0x1a0
 ext4_file_write_iter+0xef/0x3b0
 __vfs_write+0x17e/0x1e0
 vfs_write+0xa5/0x1a0
 ksys_write+0x57/0xd0
 do_syscall_64+0x55/0x160
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Tetsuo then noticed that this is because the __memcg_kmem_charge_memcg
fails __GFP_NOFAIL charge when the kmem limit is reached.  This is a wrong
behavior because nofail allocations are not allowed to fail.  Normal
charge path simply forces the charge even if that means to cross the
limit.  Kmem accounting should be doing the same.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Reported-by: Thomas Lindroth <[email protected]>
Debugged-by: Tetsuo Handa <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Thomas Lindroth <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
aiChaoSONG pushed a commit to aiChaoSONG/linux that referenced this pull request May 6, 2021
@alex
Merge pull request thesofproject#42 from wedsonaf/error_handling
4510d5a 
Simplify error handling in file operations.
bardliao pushed a commit to bardliao/linux that referenced this pull request Oct 27, 2021
@jacob-keller @davem330
ice: fix locking for Tx timestamp tracking flush
4d4a223 
Commit 4dd0d5c ("ice: add lock around Tx timestamp tracker flush")
added a lock around the Tx timestamp tracker flow which is used to
cleanup any left over SKBs and prepare for device removal.

This lock is problematic because it is being held around a call to
ice_clear_phy_tstamp. The clear function takes a mutex to send a PHY
write command to firmware. This could lead to a deadlock if the mutex
actually sleeps, and causes the following warning on a kernel with
preemption debugging enabled:

[  715.419426] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:573
[  715.427900] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 3100, name: rmmod
[  715.435652] INFO: lockdep is turned off.
[  715.439591] Preemption disabled at:
[  715.439594] [<0000000000000000>] 0x0
[  715.446678] CPU: 52 PID: 3100 Comm: rmmod Tainted: G        W  OE     5.15.0-rc4+ thesofproject#42 bdd7ec3018e725f159ca0d372ce8c2c0e784891c
[  715.458058] Hardware name: Intel Corporation S2600STQ/S2600STQ, BIOS SE5C620.86B.02.01.0010.010620200716 01/06/2020
[  715.468483] Call Trace:
[  715.470940]  dump_stack_lvl+0x6a/0x9a
[  715.474613]  ___might_sleep.cold+0x224/0x26a
[  715.478895]  __mutex_lock+0xb3/0x1440
[  715.482569]  ? stack_depot_save+0x378/0x500
[  715.486763]  ? ice_sq_send_cmd+0x78/0x14c0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.494979]  ? kfree+0xc1/0x520
[  715.498128]  ? mutex_lock_io_nested+0x12a0/0x12a0
[  715.502837]  ? kasan_set_free_info+0x20/0x30
[  715.507110]  ? __kasan_slab_free+0x10b/0x140
[  715.511385]  ? slab_free_freelist_hook+0xc7/0x220
[  715.516092]  ? kfree+0xc1/0x520
[  715.519235]  ? ice_deinit_lag+0x16c/0x220 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.527359]  ? ice_remove+0x1cf/0x6a0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.535133]  ? pci_device_remove+0xab/0x1d0
[  715.539318]  ? __device_release_driver+0x35b/0x690
[  715.544110]  ? driver_detach+0x214/0x2f0
[  715.548035]  ? bus_remove_driver+0x11d/0x2f0
[  715.552309]  ? pci_unregister_driver+0x26/0x250
[  715.556840]  ? ice_module_exit+0xc/0x2f [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.564799]  ? __do_sys_delete_module.constprop.0+0x2d8/0x4e0
[  715.570554]  ? do_syscall_64+0x3b/0x90
[  715.574303]  ? entry_SYSCALL_64_after_hwframe+0x44/0xae
[  715.579529]  ? start_flush_work+0x542/0x8f0
[  715.583719]  ? ice_sq_send_cmd+0x78/0x14c0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.591923]  ice_sq_send_cmd+0x78/0x14c0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.599960]  ? wait_for_completion_io+0x250/0x250
[  715.604662]  ? lock_acquire+0x196/0x200
[  715.608504]  ? do_raw_spin_trylock+0xa5/0x160
[  715.612864]  ice_sbq_rw_reg+0x1e6/0x2f0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.620813]  ? ice_reset+0x130/0x130 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.628497]  ? __debug_check_no_obj_freed+0x1e8/0x3c0
[  715.633550]  ? trace_hardirqs_on+0x1c/0x130
[  715.637748]  ice_write_phy_reg_e810+0x70/0xf0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.646220]  ? do_raw_spin_trylock+0xa5/0x160
[  715.650581]  ? ice_ptp_release+0x910/0x910 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.658797]  ? ice_ptp_release+0x255/0x910 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.667013]  ice_clear_phy_tstamp+0x2c/0x110 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.675403]  ice_ptp_release+0x408/0x910 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.683440]  ice_remove+0x560/0x6a0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.691037]  ? _raw_spin_unlock_irqrestore+0x46/0x73
[  715.696005]  pci_device_remove+0xab/0x1d0
[  715.700018]  __device_release_driver+0x35b/0x690
[  715.704637]  driver_detach+0x214/0x2f0
[  715.708389]  bus_remove_driver+0x11d/0x2f0
[  715.712489]  pci_unregister_driver+0x26/0x250
[  715.716857]  ice_module_exit+0xc/0x2f [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[  715.724637]  __do_sys_delete_module.constprop.0+0x2d8/0x4e0
[  715.730210]  ? free_module+0x6d0/0x6d0
[  715.733963]  ? task_work_run+0xe1/0x170
[  715.737803]  ? exit_to_user_mode_loop+0x17f/0x1d0
[  715.742509]  ? rcu_read_lock_sched_held+0x12/0x80
[  715.747215]  ? trace_hardirqs_on+0x1c/0x130
[  715.751401]  do_syscall_64+0x3b/0x90
[  715.754981]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  715.760033] RIP: 0033:0x7f4dfe59000b
[  715.763612] Code: 73 01 c3 48 8b 0d 6d 1e 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3d 1e 0c 00 f7 d8 64 89 01 48
[  715.782357] RSP: 002b:00007ffe8c891708 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[  715.789923] RAX: ffffffffffffffda RBX: 00005558a20468b0 RCX: 00007f4dfe59000b
[  715.797054] RDX: 000000000000000a RSI: 0000000000000800 RDI: 00005558a2046918
[  715.804189] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[  715.811319] R10: 00007f4dfe603ac0 R11: 0000000000000206 R12: 00007ffe8c891940
[  715.818455] R13: 00007ffe8c8920a3 R14: 00005558a20462a0 R15: 00005558a20468b0

Notice that this is the only case where we use the lock in this way. In
the cleanup kthread and work kthread the lock is only taken around the
bit accesses. This was done intentionally to avoid this kind of issue.
The way the lock is used, we only protect ordering of bit sets vs bit
clears. The Tx writers in the hot path don't need to be protected
against the entire kthread loop. The Tx queues threads only need to
ensure that they do not re-use an index that is currently in use. The
cleanup loop does not need to block all new set bits, since it will
re-queue itself if new timestamps are present.

Fix the tracker flow so that it uses the same flow as the standard
cleanup thread. In addition, ensure the in_use bitmap actually gets
cleared properly.

This fixes the warning and also avoids the potential deadlock that might
have occurred otherwise.

Fixes: 4dd0d5c ("ice: add lock around Tx timestamp tracker flush")
Signed-off-by: Jacob Keller <[email protected]>
Signed-off-by: Tony Nguyen <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
kuanhsuncheng pushed a commit to kuanhsuncheng/linux that referenced this pull request Jan 10, 2022
@alobakin @kuba-moo
net: fix premature exit from NAPI state polling in napi_disable()
0315a07 
Commit 719c571 ("net: make napi_disable() symmetric with
enable") accidentally introduced a bug sometimes leading to a kernel
BUG when bringing an iface up/down under heavy traffic load.

Prior to this commit, napi_disable() was polling n->state until
none of (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC) is set and then
always flip them. Now there's a possibility to get away with the
NAPIF_STATE_SCHE unset as 'continue' drops us to the cmpxchg()
call with an uninitialized variable, rather than straight to
another round of the state check.

Error path looks like:

napi_disable():
unsigned long val, new; /* new is uninitialized */

do {
	val = READ_ONCE(n->state); /* NAPIF_STATE_NPSVC and/or
				      NAPIF_STATE_SCHED is set */
	if (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) { /* true */
		usleep_range(20, 200);
		continue; /* go straight to the condition check */
	}
	new = val | <...>
} while (cmpxchg(&n->state, val, new) != val); /* state == val, cmpxchg()
						  writes garbage */

napi_enable():
do {
	val = READ_ONCE(n->state);
	BUG_ON(!test_bit(NAPI_STATE_SCHED, &val)); /* 50/50 boom */
<...>

while the typical BUG splat is like:

[  172.652461] ------------[ cut here ]------------
[  172.652462] kernel BUG at net/core/dev.c:6937!
[  172.656914] invalid opcode: 0000 [thesofproject#1] PREEMPT SMP PTI
[  172.661966] CPU: 36 PID: 2829 Comm: xdp_redirect_cp Tainted: G          I       5.15.0 thesofproject#42
[  172.670222] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0014.082620210524 08/26/2021
[  172.680646] RIP: 0010:napi_enable+0x5a/0xd0
[  172.684832] Code: 07 49 81 cc 00 01 00 00 4c 89 e2 48 89 d8 80 e6 fb f0 48 0f b1 55 10 48 39 c3 74 10 48 8b 5d 10 f6 c7 04 75 3d f6 c3 01 75 b4 <0f> 0b 5b 5d 41 5c c3 65 ff 05 b8 e5 61 53 48 c7 c6 c0 f3 34 ad 48
[  172.703578] RSP: 0018:ffffa3c9497477a8 EFLAGS: 00010246
[  172.708803] RAX: ffffa3c96615a014 RBX: 0000000000000000 RCX: ffff8a4b575301a0
< snip >
[  172.782403] Call Trace:
[  172.784857]  <TASK>
[  172.786963]  ice_up_complete+0x6f/0x210 [ice]
[  172.791349]  ice_xdp+0x136/0x320 [ice]
[  172.795108]  ? ice_change_mtu+0x180/0x180 [ice]
[  172.799648]  dev_xdp_install+0x61/0xe0
[  172.803401]  dev_xdp_attach+0x1e0/0x550
[  172.807240]  dev_change_xdp_fd+0x1e6/0x220
[  172.811338]  do_setlink+0xee8/0x1010
[  172.814917]  rtnl_setlink+0xe5/0x170
[  172.818499]  ? bpf_lsm_binder_set_context_mgr+0x10/0x10
[  172.823732]  ? security_capable+0x36/0x50
< snip >

Fix this by replacing 'do { } while (cmpxchg())' with an "infinite"
for-loop with an explicit break.

From v1 [0]:
 - just use a for-loop to simplify both the fix and the existing
   code (Eric).

[0] https://lore.kernel.org/netdev/[email protected]

Fixes: 719c571 ("net: make napi_disable() symmetric with enable")
Suggested-by: Eric Dumazet <[email protected]> # for-loop
Signed-off-by: Alexander Lobakin <[email protected]>
Reviewed-by: Jesse Brandeburg <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
plbossart pushed a commit that referenced this pull request Jun 16, 2023
@davem330
net/smc: Reset connection when trying to use SMCRv2 fails.
3511227 
We found a crash when using SMCRv2 with 2 Mellanox ConnectX-4. It
can be reproduced by:

- smc_run nginx
- smc_run wrk -t 32 -c 500 -d 30 http://<ip>:<port>

 BUG: kernel NULL pointer dereference, address: 0000000000000014
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 8000000108713067 P4D 8000000108713067 PUD 151127067 PMD 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 4 PID: 2441 Comm: kworker/4:249 Kdump: loaded Tainted: G        W   E      6.4.0-rc1+ #42
 Workqueue: smc_hs_wq smc_listen_work [smc]
 RIP: 0010:smc_clc_send_confirm_accept+0x284/0x580 [smc]
 RSP: 0018:ffffb8294b2d7c78 EFLAGS: 00010a06
 RAX: ffff8f1873238880 RBX: ffffb8294b2d7dc8 RCX: 0000000000000000
 RDX: 00000000000000b4 RSI: 0000000000000001 RDI: 0000000000b40c00
 RBP: ffffb8294b2d7db8 R08: ffff8f1815c5860c R09: 0000000000000000
 R10: 0000000000000400 R11: 0000000000000000 R12: ffff8f1846f56180
 R13: ffff8f1815c5860c R14: 0000000000000001 R15: 0000000000000001
 FS:  0000000000000000(0000) GS:ffff8f1aefd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000014 CR3: 00000001027a0001 CR4: 00000000003706e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  <TASK>
  ? mlx5_ib_map_mr_sg+0xa1/0xd0 [mlx5_ib]
  ? smcr_buf_map_link+0x24b/0x290 [smc]
  ? __smc_buf_create+0x4ee/0x9b0 [smc]
  smc_clc_send_accept+0x4c/0xb0 [smc]
  smc_listen_work+0x346/0x650 [smc]
  ? __schedule+0x279/0x820
  process_one_work+0x1e5/0x3f0
  worker_thread+0x4d/0x2f0
  ? __pfx_worker_thread+0x10/0x10
  kthread+0xe5/0x120
  ? __pfx_kthread+0x10/0x10
  ret_from_fork+0x2c/0x50
  </TASK>

During the CLC handshake, server sequentially tries available SMCRv2
and SMCRv1 devices in smc_listen_work().

If an SMCRv2 device is found. SMCv2 based link group and link will be
assigned to the connection. Then assumed that some buffer assignment
errors happen later in the CLC handshake, such as RMB registration
failure, server will give up SMCRv2 and try SMCRv1 device instead. But
the resources assigned to the connection won't be reset.

When server tries SMCRv1 device, the connection creation process will
be executed again. Since conn->lnk has been assigned when trying SMCRv2,
it will not be set to the correct SMCRv1 link in
smcr_lgr_conn_assign_link(). So in such situation, conn->lgr points to
correct SMCRv1 link group but conn->lnk points to the SMCRv2 link
mistakenly.

Then in smc_clc_send_confirm_accept(), conn->rmb_desc->mr[link->link_idx]
will be accessed. Since the link->link_idx is not correct, the related
MR may not have been initialized, so crash happens.

 | Try SMCRv2 device first
 |     |-> conn->lgr:	assign existed SMCRv2 link group;
 |     |-> conn->link:	assign existed SMCRv2 link (link_idx may be 1 in SMC_LGR_SYMMETRIC);
 |     |-> sndbuf & RMB creation fails, quit;
 |
 | Try SMCRv1 device then
 |     |-> conn->lgr:	create SMCRv1 link group and assign;
 |     |-> conn->link:	keep SMCRv2 link mistakenly;
 |     |-> sndbuf & RMB creation succeed, only RMB->mr[link_idx = 0]
 |         initialized.
 |
 | Then smc_clc_send_confirm_accept() accesses
 | conn->rmb_desc->mr[conn->link->link_idx, which is 1], then crash.
 v

This patch tries to fix this by cleaning conn->lnk before assigning
link. In addition, it is better to reset the connection and clean the
resources assigned if trying SMCRv2 failed in buffer creation or
registration.

Fixes: e49300a ("net/smc: add listen processing for SMC-Rv2")
Link: https://lore.kernel.org/r/[email protected]/
Signed-off-by: Wen Gu <[email protected]>
Reviewed-by: Tony Lu <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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3 participants
@xiulipan @ranj063 @plbossart