[WORKAROUND]ASoC: SOF: Intel: hda: disable runtime PM #6
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Signed-off-by: Ranjani Sridharan <[email protected]>
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… allocation
After memory allocation failure vc_allocate() doesn't clean up data
which has been initialized in visual_init(). In case of fbcon this
leads to divide-by-0 in fbcon_init() on next open of the same tty.
memory allocation in vc_allocate() may fail here:
1097: vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
on next open() fbcon_init() skips vc_font.data initialization:
1088: if (!p->fontdata) {
division by zero in fbcon_init() happens here:
1149: new_cols /= vc->vc_font.width;
Additional check is needed in fbcon_deinit() to prevent
usage of uninitialized vc_screenbuf:
1251: if (vc->vc_hi_font_mask && vc->vc_screenbuf)
1252: set_vc_hi_font(vc, false);
Crash:
#6 [ffffc90001eafa60] divide_error at ffffffff81a00be4
[exception RIP: fbcon_init+463]
RIP: ffffffff814b860f RSP: ffffc90001eafb18 RFLAGS: 00010246
...
#7 [ffffc90001eafb60] visual_init at ffffffff8154c36e
thesofproject#8 [ffffc90001eafb80] vc_allocate at ffffffff8154f53c
thesofproject#9 [ffffc90001eafbc8] con_install at ffffffff8154f624
...
Signed-off-by: Grzegorz Halat <[email protected]>
Reviewed-by: Oleksandr Natalenko <[email protected]>
Acked-by: Bartlomiej Zolnierkiewicz <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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When we have holes in a normal memory zone, we could endup having cached_migrate_pfns which may not necessarily be valid, under heavy memory pressure with swapping enabled ( via __reset_isolation_suitable(), triggered by kswapd). Later if we fail to find a page via fast_isolate_freepages(), we may end up using the migrate_pfn we started the search with, as valid page. This could lead to accessing NULL pointer derefernces like below, due to an invalid mem_section pointer. Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 [47/1825] Mem abort info: ESR = 0x96000004 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp = 0000000082f94ae9 [0000000000000008] pgd=0000000000000000 Internal error: Oops: 96000004 [#1] SMP ... CPU: 10 PID: 6080 Comm: qemu-system-aar Not tainted 510-rc1+ #6 Hardware name: AmpereComputing(R) OSPREY EV-883832-X3-0001/OSPREY, BIOS 4819 09/25/2018 pstate: 60000005 (nZCv daif -PAN -UAO) pc : set_pfnblock_flags_mask+0x58/0xe8 lr : compaction_alloc+0x300/0x950 [...] Process qemu-system-aar (pid: 6080, stack limit = 0x0000000095070da5) Call trace: set_pfnblock_flags_mask+0x58/0xe8 compaction_alloc+0x300/0x950 migrate_pages+0x1a4/0xbb0 compact_zone+0x750/0xde8 compact_zone_order+0xd8/0x118 try_to_compact_pages+0xb4/0x290 __alloc_pages_direct_compact+0x84/0x1e0 __alloc_pages_nodemask+0x5e0/0xe18 alloc_pages_vma+0x1cc/0x210 do_huge_pmd_anonymous_page+0x108/0x7c8 __handle_mm_fault+0xdd4/0x1190 handle_mm_fault+0x114/0x1c0 __get_user_pages+0x198/0x3c0 get_user_pages_unlocked+0xb4/0x1d8 __gfn_to_pfn_memslot+0x12c/0x3b8 gfn_to_pfn_prot+0x4c/0x60 kvm_handle_guest_abort+0x4b0/0xcd8 handle_exit+0x140/0x1b8 kvm_arch_vcpu_ioctl_run+0x260/0x768 kvm_vcpu_ioctl+0x490/0x898 do_vfs_ioctl+0xc4/0x898 ksys_ioctl+0x8c/0xa0 __arm64_sys_ioctl+0x28/0x38 el0_svc_common+0x74/0x118 el0_svc_handler+0x38/0x78 el0_svc+0x8/0xc Code: f860784 f100001f 8b011401 9a801020 (f9400400) ---[ end trace af6a35219325a9b6 ]--- The issue was reported on an arm64 server with 128GB with holes in the zone (e.g, [32GB@4GB, 96GB@544GB]), with a swap device enabled, while running 100 KVM guest instances. This patch fixes the issue by ensuring that the page belongs to a valid PFN when we fallback to using the lower limit of the scan range upon failure in fast_isolate_freepages(). Link: http://lkml.kernel.org/r/[email protected] Fixes: 5a81188 ("mm, compaction: use free lists to quickly locate a migration target") Signed-off-by: Suzuki K Poulose <[email protected]> Reported-by: Marc Zyngier <[email protected]> Reviewed-by: Mel Gorman <[email protected]> Reviewed-by: Anshuman Khandual <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Qian Cai <[email protected]> Cc: Marc Zyngier <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
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This patch addresses below two issues and prepares the code to address
3rd issue listed below.
1. mdev device is placed on the mdev bus before it is created in the
vendor driver. Once a device is placed on the mdev bus without creating
its supporting underlying vendor device, mdev driver's probe() gets
triggered. However there isn't a stable mdev available to work on.
create_store()
mdev_create_device()
device_register()
...
vfio_mdev_probe()
[...]
parent->ops->create()
vfio_ap_mdev_create()
mdev_set_drvdata(mdev, matrix_mdev);
/* Valid pointer set above */
Due to this way of initialization, mdev driver who wants to use the mdev,
doesn't have a valid mdev to work on.
2. Current creation sequence is,
parent->ops_create()
groups_register()
Remove sequence is,
parent->ops->remove()
groups_unregister()
However, remove sequence should be exact mirror of creation sequence.
Once this is achieved, all users of the mdev will be terminated first
before removing underlying vendor device.
(Follow standard linux driver model).
At that point vendor's remove() ops shouldn't fail because taking the
device off the bus should terminate any usage.
3. When remove operation fails, mdev sysfs removal attempts to add the
file back on already removed device. Following call trace [1] is observed.
[1] call trace:
kernel: WARNING: CPU: 2 PID: 9348 at fs/sysfs/file.c:327 sysfs_create_file_ns+0x7f/0x90
kernel: CPU: 2 PID: 9348 Comm: bash Kdump: loaded Not tainted 5.1.0-rc6-vdevbus+ #6
kernel: Hardware name: Supermicro SYS-6028U-TR4+/X10DRU-i+, BIOS 2.0b 08/09/2016
kernel: RIP: 0010:sysfs_create_file_ns+0x7f/0x90
kernel: Call Trace:
kernel: remove_store+0xdc/0x100 [mdev]
kernel: kernfs_fop_write+0x113/0x1a0
kernel: vfs_write+0xad/0x1b0
kernel: ksys_write+0x5a/0xe0
kernel: do_syscall_64+0x5a/0x210
kernel: entry_SYSCALL_64_after_hwframe+0x49/0xbe
Therefore, mdev core is improved in following ways.
1. Split the device registration/deregistration sequence so that some
things can be done between initialization of the device and hooking it
up to the bus respectively after deregistering it from the bus but
before giving up our final reference.
In particular, this means invoking the ->create() and ->remove()
callbacks in those new windows. This gives the vendor driver an
initialized mdev device to work with during creation.
At the same time, a bus driver who wish to bind to mdev driver also
gets initialized mdev device.
This follows standard Linux kernel bus and device model.
2. During remove flow, first remove the device from the bus. This
ensures that any bus specific devices are removed.
Once device is taken off the mdev bus, invoke remove() of mdev
from the vendor driver.
3. The driver core device model provides way to register and auto
unregister the device sysfs attribute groups at dev->groups.
Make use of dev->groups to let core create the groups and eliminate
code to avoid explicit groups creation and removal.
To ensure, that new sequence is solid, a below stack dump of a
process is taken who attempts to remove the device while device is in
use by vfio driver and user application.
This stack dump validates that vfio driver guards against such device
removal when device is in use.
cat /proc/21962/stack
[<0>] vfio_del_group_dev+0x216/0x3c0 [vfio]
[<0>] mdev_remove+0x21/0x40 [mdev]
[<0>] device_release_driver_internal+0xe8/0x1b0
[<0>] bus_remove_device+0xf9/0x170
[<0>] device_del+0x168/0x350
[<0>] mdev_device_remove_common+0x1d/0x50 [mdev]
[<0>] mdev_device_remove+0x8c/0xd0 [mdev]
[<0>] remove_store+0x71/0x90 [mdev]
[<0>] kernfs_fop_write+0x113/0x1a0
[<0>] vfs_write+0xad/0x1b0
[<0>] ksys_write+0x5a/0xe0
[<0>] do_syscall_64+0x5a/0x210
[<0>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[<0>] 0xffffffffffffffff
This prepares the code to eliminate calling device_create_file() in
subsequent patch.
Reviewed-by: Cornelia Huck <[email protected]>
Signed-off-by: Parav Pandit <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>
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If device is removal is initiated by two threads as below, mdev core
attempts to create a syfs remove file on stale device.
During this flow, below [1] call trace is observed.
cpu-0 cpu-1
----- -----
mdev_unregister_device()
device_for_each_child
mdev_device_remove_cb
mdev_device_remove
user_syscall
remove_store()
mdev_device_remove()
[..]
unregister device();
/* not found in list or
* active=false.
*/
sysfs_create_file()
..Call trace
Now that mdev core follows correct device removal sequence of the linux
bus model, remove shouldn't fail in normal cases. If it fails, there is
no point of creating a stale file or checking for specific error status.
kernel: WARNING: CPU: 2 PID: 9348 at fs/sysfs/file.c:327
sysfs_create_file_ns+0x7f/0x90
kernel: CPU: 2 PID: 9348 Comm: bash Kdump: loaded Not tainted
5.1.0-rc6-vdevbus+ #6
kernel: Hardware name: Supermicro SYS-6028U-TR4+/X10DRU-i+, BIOS 2.0b
08/09/2016
kernel: RIP: 0010:sysfs_create_file_ns+0x7f/0x90
kernel: Call Trace:
kernel: remove_store+0xdc/0x100 [mdev]
kernel: kernfs_fop_write+0x113/0x1a0
kernel: vfs_write+0xad/0x1b0
kernel: ksys_write+0x5a/0xe0
kernel: do_syscall_64+0x5a/0x210
kernel: entry_SYSCALL_64_after_hwframe+0x49/0xbe
Reviewed-by: Cornelia Huck <[email protected]>
Signed-off-by: Parav Pandit <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>
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In following sequences, child devices created while removing mdev parent
device can be left out, or it may lead to race of removing half
initialized child mdev devices.
issue-1:
--------
cpu-0 cpu-1
----- -----
mdev_unregister_device()
device_for_each_child()
mdev_device_remove_cb()
mdev_device_remove()
create_store()
mdev_device_create() [...]
device_add()
parent_remove_sysfs_files()
/* BUG: device added by cpu-0
* whose parent is getting removed
* and it won't process this mdev.
*/
issue-2:
--------
Below crash is observed when user initiated remove is in progress
and mdev_unregister_driver() completes parent unregistration.
cpu-0 cpu-1
----- -----
remove_store()
mdev_device_remove()
active = false;
mdev_unregister_device()
parent device removed.
[...]
parents->ops->remove()
/*
* BUG: Accessing invalid parent.
*/
This is similar race like create() racing with mdev_unregister_device().
BUG: unable to handle kernel paging request at ffffffffc0585668
PGD e8f618067 P4D e8f618067 PUD e8f61a067 PMD 85adca067 PTE 0
Oops: 0000 [#1] SMP PTI
CPU: 41 PID: 37403 Comm: bash Kdump: loaded Not tainted 5.1.0-rc6-vdevbus+ #6
Hardware name: Supermicro SYS-6028U-TR4+/X10DRU-i+, BIOS 2.0b 08/09/2016
RIP: 0010:mdev_device_remove+0xfa/0x140 [mdev]
Call Trace:
remove_store+0x71/0x90 [mdev]
kernfs_fop_write+0x113/0x1a0
vfs_write+0xad/0x1b0
ksys_write+0x5a/0xe0
do_syscall_64+0x5a/0x210
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Therefore, mdev core is improved as below to overcome above issues.
Wait for any ongoing mdev create() and remove() to finish before
unregistering parent device.
This continues to allow multiple create and remove to progress in
parallel for different mdev devices as most common case.
At the same time guard parent removal while parent is being accessed by
create() and remove() callbacks.
create()/remove() and unregister_device() are synchronized by the rwsem.
Refactor device removal code to mdev_device_remove_common() to avoid
acquiring unreg_sem of the parent.
Fixes: 7b96953 ("vfio: Mediated device Core driver")
Signed-off-by: Parav Pandit <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>
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Ido Schimmel says: ==================== mlxsw: Various fixes This patchset contains various fixes for mlxsw. Patch #1 fixes an hash polarization problem when a nexthop device is a LAG device. This is caused by the fact that the same seed is used for the LAG and ECMP hash functions. Patch #2 fixes an issue in which the driver fails to refresh a nexthop neighbour after it becomes dead. This prevents the nexthop from ever being written to the adjacency table and used to forward traffic. Patch Patch #4 fixes a wrong extraction of TOS value in flower offload code. Patch #5 is a test case. Patch #6 works around a buffer issue in Spectrum-2 by reducing the default sizes of the shared buffer pools. Patch #7 prevents prio-tagged packets from entering the switch when PVID is removed from the bridge port. Please consider patches #2, #4 and #6 for 5.1.y ==================== Signed-off-by: David S. Miller <[email protected]>
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…is valid When booting with amd_iommu=off, the following WARNING message appears: AMD-Vi: AMD IOMMU disabled on kernel command-line ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/workqueue.c:2772 flush_workqueue+0x42e/0x450 Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.5.0-rc3-amd-iommu #6 Hardware name: Lenovo ThinkSystem SR655-2S/7D2WRCZ000, BIOS D8E101L-1.00 12/05/2019 RIP: 0010:flush_workqueue+0x42e/0x450 Code: ff 0f 0b e9 7a fd ff ff 4d 89 ef e9 33 fe ff ff 0f 0b e9 7f fd ff ff 0f 0b e9 bc fd ff ff 0f 0b e9 a8 fd ff ff e8 52 2c fe ff <0f> 0b 31 d2 48 c7 c6 e0 88 c5 95 48 c7 c7 d8 ad f0 95 e8 19 f5 04 Call Trace: kmem_cache_destroy+0x69/0x260 iommu_go_to_state+0x40c/0x5ab amd_iommu_prepare+0x16/0x2a irq_remapping_prepare+0x36/0x5f enable_IR_x2apic+0x21/0x172 default_setup_apic_routing+0x12/0x6f apic_intr_mode_init+0x1a1/0x1f1 x86_late_time_init+0x17/0x1c start_kernel+0x480/0x53f secondary_startup_64+0xb6/0xc0 ---[ end trace 30894107c3749449 ]--- x2apic: IRQ remapping doesn't support X2APIC mode x2apic disabled The warning is caused by the calling of 'kmem_cache_destroy()' in free_iommu_resources(). Here is the call path: free_iommu_resources kmem_cache_destroy flush_memcg_workqueue flush_workqueue The root cause is that the IOMMU subsystem runs before the workqueue subsystem, which the variable 'wq_online' is still 'false'. This leads to the statement 'if (WARN_ON(!wq_online))' in flush_workqueue() is 'true'. Since the variable 'memcg_kmem_cache_wq' is not allocated during the time, it is unnecessary to call flush_memcg_workqueue(). This prevents the WARNING message triggered by flush_workqueue(). Link: http://lkml.kernel.org/r/[email protected] Fixes: 92ee383 ("mm: fix race between kmem_cache destroy, create and deactivate") Signed-off-by: Adrian Huang <[email protected]> Reported-by: Xiaochun Lee <[email protected]> Reviewed-by: Shakeel Butt <[email protected]> Cc: Joerg Roedel <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: David Rientjes <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
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Ido Schimmel says: ==================== mlxsw: Various fixes This patch set contains various fixes for mlxsw. Patch #1 splits the init() callback between Spectrum-2 and Spectrum-3 in order to avoid enforcing the same firmware version for both ASICs, as this can't possibly work. Without this patch the driver cannot boot with the Spectrum-3 ASIC. Patches #2-#3 fix a long standing race condition that was recently exposed while testing the driver on an emulator, which is very slow compared to the actual hardware. The problem is explained in detail in the commit messages. Patch #4 fixes a selftest. Patch #5 prevents offloaded qdiscs from presenting a non-zero backlog to the user when the netdev is down. This is done by clearing the cached backlog in the driver when the netdev goes down. Patch #6 fixes qdisc statistics (backlog and tail drops) to also take into account the multicast traffic classes. v2: * Patches #2-#3: use skb_cow_head() instead of skb_unshare() as suggested by Jakub. Remove unnecessary check regarding headroom * Patches #5-#6: new ==================== Signed-off-by: David S. Miller <[email protected]>
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The req->body should be updated before req->state is updated and the order should be guaranteed by a barrier. Otherwise, read_reply() might return req->body = NULL. Below is sample callstack when the issue is reproduced on purpose by reordering the updates of req->body and req->state and adding delay in code between updates of req->state and req->body. [ 22.356105] general protection fault: 0000 [#1] SMP PTI [ 22.361185] CPU: 2 PID: 52 Comm: xenwatch Not tainted 5.5.0xen+ #6 [ 22.366727] Hardware name: Xen HVM domU, BIOS ... [ 22.372245] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60 ... ... [ 22.392163] RSP: 0018:ffffb2d64023fdf0 EFLAGS: 00010246 [ 22.395933] RAX: 0000000000000000 RBX: 75746e7562755f6d RCX: 0000000000000000 [ 22.400871] RDX: 0000000000000000 RSI: ffffb2d64023fdfc RDI: 75746e7562755f6d [ 22.405874] RBP: 0000000000000000 R08: 00000000000001e8 R09: 0000000000cdcdcd [ 22.410945] R10: ffffb2d6402ffe00 R11: ffff9d95395eaeb0 R12: ffff9d9535935000 [ 22.417613] R13: ffff9d9526d4a000 R14: ffff9d9526f4f340 R15: ffff9d9537654000 [ 22.423726] FS: 0000000000000000(0000) GS:ffff9d953bc80000(0000) knlGS:0000000000000000 [ 22.429898] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 22.434342] CR2: 000000c4206a9000 CR3: 00000001ea3fc002 CR4: 00000000001606e0 [ 22.439645] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 22.444941] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 22.450342] Call Trace: [ 22.452509] simple_strtoull+0x27/0x70 [ 22.455572] xenbus_transaction_start+0x31/0x50 [ 22.459104] netback_changed+0x76c/0xcc1 [xen_netfront] [ 22.463279] ? find_watch+0x40/0x40 [ 22.466156] xenwatch_thread+0xb4/0x150 [ 22.469309] ? wait_woken+0x80/0x80 [ 22.472198] kthread+0x10e/0x130 [ 22.474925] ? kthread_park+0x80/0x80 [ 22.477946] ret_from_fork+0x35/0x40 [ 22.480968] Modules linked in: xen_kbdfront xen_fbfront(+) xen_netfront xen_blkfront [ 22.486783] ---[ end trace a9222030a747c3f7 ]--- [ 22.490424] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60 The virt_rmb() is added in the 'true' path of test_reply(). The "while" is changed to "do while" so that test_reply() is used as a read memory barrier. Signed-off-by: Dongli Zhang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Reviewed-by: Julien Grall <[email protected]> Signed-off-by: Boris Ostrovsky <[email protected]>
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This BUG halt was reported a while back, but the patch somehow got missed: PID: 2879 TASK: c16adaa0 CPU: 1 COMMAND: "sctpn" #0 [f418dd28] crash_kexec at c04a7d8c #1 [f418dd7c] oops_end at c0863e02 #2 [f418dd90] do_invalid_op at c040aaca #3 [f418de28] error_code (via invalid_op) at c08631a5 EAX: f34baac0 EBX: 00000090 ECX: f418deb0 EDX: f5542950 EBP: 00000000 DS: 007b ESI: f34ba800 ES: 007b EDI: f418dea0 GS: 00e0 CS: 0060 EIP: c046fa5e ERR: ffffffff EFLAGS: 00010286 #4 [f418de5c] add_timer at c046fa5e #5 [f418de68] sctp_do_sm at f8db8c77 [sctp] #6 [f418df30] sctp_primitive_SHUTDOWN at f8dcc1b5 [sctp] #7 [f418df48] inet_shutdown at c080baf9 thesofproject#8 [f418df5c] sys_shutdown at c079eedf thesofproject#9 [f418df7] sys_socketcall at c079fe88 EAX: ffffffda EBX: 0000000d ECX: bfceea90 EDX: 0937af98 DS: 007b ESI: 0000000c ES: 007b EDI: b7150ae4 SS: 007b ESP: bfceea7c EBP: bfceeaa8 GS: 0033 CS: 0073 EIP: b775c424 ERR: 00000066 EFLAGS: 00000282 It appears that the side effect that starts the shutdown timer was processed multiple times, which can happen as multiple paths can trigger it. This of course leads to the BUG halt in add_timer getting called. Fix seems pretty straightforward, just check before the timer is added if its already been started. If it has mod the timer instead to min(current expiration, new expiration) Its been tested but not confirmed to fix the problem, as the issue has only occured in production environments where test kernels are enjoined from being installed. It appears to be a sane fix to me though. Also, recentely, Jere found a reproducer posted on list to confirm that this resolves the issues Signed-off-by: Neil Horman <[email protected]> CC: Vlad Yasevich <[email protected]> CC: "David S. Miller" <[email protected]> CC: [email protected] CC: [email protected] CC: [email protected] Acked-by: Marcelo Ricardo Leitner <[email protected]> Signed-off-by: David S. Miller <[email protected]>
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Like other tunneling interfaces, the bareudp doesn't need TXLOCK.
So, It is good to set the NETIF_F_LLTX flag to improve performance and
to avoid lockdep's false-positive warning.
Test commands:
ip netns add A
ip netns add B
ip link add veth0 netns A type veth peer name veth1 netns B
ip netns exec A ip link set veth0 up
ip netns exec A ip a a 10.0.0.1/24 dev veth0
ip netns exec B ip link set veth1 up
ip netns exec B ip a a 10.0.0.2/24 dev veth1
for i in {2..1}
do
let A=$i-1
ip netns exec A ip link add bareudp$i type bareudp \
dstport $i ethertype ip
ip netns exec A ip link set bareudp$i up
ip netns exec A ip a a 10.0.$i.1/24 dev bareudp$i
ip netns exec A ip r a 10.0.$i.2 encap ip src 10.0.$A.1 \
dst 10.0.$A.2 via 10.0.$i.2 dev bareudp$i
ip netns exec B ip link add bareudp$i type bareudp \
dstport $i ethertype ip
ip netns exec B ip link set bareudp$i up
ip netns exec B ip a a 10.0.$i.2/24 dev bareudp$i
ip netns exec B ip r a 10.0.$i.1 encap ip src 10.0.$A.2 \
dst 10.0.$A.1 via 10.0.$i.1 dev bareudp$i
done
ip netns exec A ping 10.0.2.2
Splat looks like:
[ 96.992803][ T822] ============================================
[ 96.993954][ T822] WARNING: possible recursive locking detected
[ 96.995102][ T822] 5.10.0+ thesofproject#819 Not tainted
[ 96.995927][ T822] --------------------------------------------
[ 96.997091][ T822] ping/822 is trying to acquire lock:
[ 96.998083][ T822] ffff88810f753898 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960
[ 96.999813][ T822]
[ 96.999813][ T822] but task is already holding lock:
[ 97.001192][ T822] ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960
[ 97.002908][ T822]
[ 97.002908][ T822] other info that might help us debug this:
[ 97.004401][ T822] Possible unsafe locking scenario:
[ 97.004401][ T822]
[ 97.005784][ T822] CPU0
[ 97.006407][ T822] ----
[ 97.007010][ T822] lock(_xmit_NONE#2);
[ 97.007779][ T822] lock(_xmit_NONE#2);
[ 97.008550][ T822]
[ 97.008550][ T822] *** DEADLOCK ***
[ 97.008550][ T822]
[ 97.010057][ T822] May be due to missing lock nesting notation
[ 97.010057][ T822]
[ 97.011594][ T822] 7 locks held by ping/822:
[ 97.012426][ T822] #0: ffff888109a144f0 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0x12f7/0x2b00
[ 97.014191][ T822] #1: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020
[ 97.016045][ T822] #2: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960
[ 97.017897][ T822] #3: ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960
[ 97.019684][ T822] #4: ffffffffbce2f600 (rcu_read_lock){....}-{1:2}, at: bareudp_xmit+0x31b/0x3690 [bareudp]
[ 97.021573][ T822] #5: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020
[ 97.023424][ T822] #6: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960
[ 97.025259][ T822]
[ 97.025259][ T822] stack backtrace:
[ 97.026349][ T822] CPU: 3 PID: 822 Comm: ping Not tainted 5.10.0+ thesofproject#819
[ 97.027609][ T822] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 97.029407][ T822] Call Trace:
[ 97.030015][ T822] dump_stack+0x99/0xcb
[ 97.030783][ T822] __lock_acquire.cold.77+0x149/0x3a9
[ 97.031773][ T822] ? stack_trace_save+0x81/0xa0
[ 97.032661][ T822] ? register_lock_class+0x1910/0x1910
[ 97.033673][ T822] ? register_lock_class+0x1910/0x1910
[ 97.034679][ T822] ? rcu_read_lock_sched_held+0x91/0xc0
[ 97.035697][ T822] ? rcu_read_lock_bh_held+0xa0/0xa0
[ 97.036690][ T822] lock_acquire+0x1b2/0x730
[ 97.037515][ T822] ? __dev_queue_xmit+0x1f52/0x2960
[ 97.038466][ T822] ? check_flags+0x50/0x50
[ 97.039277][ T822] ? netif_skb_features+0x296/0x9c0
[ 97.040226][ T822] ? validate_xmit_skb+0x29/0xb10
[ 97.041151][ T822] _raw_spin_lock+0x30/0x70
[ 97.041977][ T822] ? __dev_queue_xmit+0x1f52/0x2960
[ 97.042927][ T822] __dev_queue_xmit+0x1f52/0x2960
[ 97.043852][ T822] ? netdev_core_pick_tx+0x290/0x290
[ 97.044824][ T822] ? mark_held_locks+0xb7/0x120
[ 97.045712][ T822] ? lockdep_hardirqs_on_prepare+0x12c/0x3e0
[ 97.046824][ T822] ? __local_bh_enable_ip+0xa5/0xf0
[ 97.047771][ T822] ? ___neigh_create+0x12a8/0x1eb0
[ 97.048710][ T822] ? trace_hardirqs_on+0x41/0x120
[ 97.049626][ T822] ? ___neigh_create+0x12a8/0x1eb0
[ 97.050556][ T822] ? __local_bh_enable_ip+0xa5/0xf0
[ 97.051509][ T822] ? ___neigh_create+0x12a8/0x1eb0
[ 97.052443][ T822] ? check_chain_key+0x244/0x5f0
[ 97.053352][ T822] ? rcu_read_lock_bh_held+0x56/0xa0
[ 97.054317][ T822] ? ip_finish_output2+0x6ea/0x2020
[ 97.055263][ T822] ? pneigh_lookup+0x410/0x410
[ 97.056135][ T822] ip_finish_output2+0x6ea/0x2020
[ ... ]
Acked-by: Guillaume Nault <[email protected]>
Fixes: 571912c ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Taehee Yoo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
lyakh
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Jan 28, 2021
We had kernel panic, it is caused by unload module and last close confirmation. call trace: [1196029.743127] free_sess+0x15/0x50 [rtrs_client] [1196029.743128] rtrs_clt_close+0x4c/0x70 [rtrs_client] [1196029.743129] ? rnbd_clt_unmap_device+0x1b0/0x1b0 [rnbd_client] [1196029.743130] close_rtrs+0x25/0x50 [rnbd_client] [1196029.743131] rnbd_client_exit+0x93/0xb99 [rnbd_client] [1196029.743132] __x64_sys_delete_module+0x190/0x260 And in the crashdump confirmation kworker is also running. PID: 6943 TASK: ffff9e2ac8098000 CPU: 4 COMMAND: "kworker/4:2" #0 [ffffb206cf337c30] __schedule at ffffffff9f93f891 #1 [ffffb206cf337cc8] schedule at ffffffff9f93fe98 #2 [ffffb206cf337cd0] schedule_timeout at ffffffff9f943938 #3 [ffffb206cf337d50] wait_for_completion at ffffffff9f9410a7 #4 [ffffb206cf337da0] __flush_work at ffffffff9f08ce0e #5 [ffffb206cf337e20] rtrs_clt_close_conns at ffffffffc0d5f668 [rtrs_client] #6 [ffffb206cf337e48] rtrs_clt_close at ffffffffc0d5f801 [rtrs_client] #7 [ffffb206cf337e68] close_rtrs at ffffffffc0d26255 [rnbd_client] thesofproject#8 [ffffb206cf337e78] free_sess at ffffffffc0d262ad [rnbd_client] thesofproject#9 [ffffb206cf337e88] rnbd_clt_put_dev at ffffffffc0d266a7 [rnbd_client] The problem is both code path try to close same session, which lead to panic. To fix it, just skip the sess if the refcount already drop to 0. Fixes: f7a7a5c ("block/rnbd: client: main functionality") Signed-off-by: Jack Wang <[email protected]> Reviewed-by: Gioh Kim <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
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Signed-off-by: Ranjani Sridharan [email protected]