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@ranj063 ranj063 commented May 24, 2019

Set the autosuspend delay for hda bus device. This prevents
the hda codec device from entering runtime suspend
when running stress tests involving opening/closing
streams one after the other.

Signed-off-by: Ranjani Sridharan ranjani.sridharan@linux.intel.com

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But why is suspending and resuming bad? In principle too frequent suspend / resume should only result in some performance loss, but shouldn't break the functionality. I think we do want this patch eventually, but if we apply it now, I think it has a high potential of hiding the problem...

Set the autosuspend delay for hda bus device. This prevents
the hda codec device from entering runtime suspend
when running stress tests involving opening/closing
streams one after the other.

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
@ranj063 ranj063 force-pushed the fix/ipc-timeout branch from 4d41340 to d2ef58a Compare May 28, 2019 15:30
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ranj063 commented May 28, 2019

@lyakh updated the placement of autosuspend delay now

@lyakh lyakh merged commit d8b5fdd into lyakh:ipc-timeout May 28, 2019
lyakh pushed a commit that referenced this pull request Jun 17, 2019
…text

stub_probe() and stub_disconnect() call functions which could call
sleeping function in invalid context whil holding busid_lock.

Fix the problem by refining the lock holds to short critical sections
to change the busid_priv fields. This fix restructures the code to
limit the lock holds in stub_probe() and stub_disconnect().

stub_probe():

[15217.927028] BUG: sleeping function called from invalid context at mm/slab.h:418
[15217.927038] in_atomic(): 1, irqs_disabled(): 0, pid: 29087, name: usbip
[15217.927044] 5 locks held by usbip/29087:
[15217.927047]  #0: 0000000091647f28 (sb_writers#6){....}, at: vfs_write+0x191/0x1c0
[15217.927062]  #1: 000000008f9ba75b (&of->mutex){....}, at: kernfs_fop_write+0xf7/0x1b0
[15217.927072]  #2: 00000000872e5b4b (&dev->mutex){....}, at: __device_driver_lock+0x3b/0x50
[15217.927082]  #3: 00000000e74ececc (&dev->mutex){....}, at: __device_driver_lock+0x46/0x50
[15217.927090]  #4: 00000000b20abbe0 (&(&busid_table[i].busid_lock)->rlock){....}, at: get_busid_priv+0x48/0x60 [usbip_host]
[15217.927103] CPU: 3 PID: 29087 Comm: usbip Tainted: G        W         5.1.0-rc6+ thesofproject#40
[15217.927106] Hardware name: Dell Inc. OptiPlex 790/0HY9JP, BIOS A18 09/24/2013
[15217.927109] Call Trace:
[15217.927118]  dump_stack+0x63/0x85
[15217.927127]  ___might_sleep+0xff/0x120
[15217.927133]  __might_sleep+0x4a/0x80
[15217.927143]  kmem_cache_alloc_trace+0x1aa/0x210
[15217.927156]  stub_probe+0xe8/0x440 [usbip_host]
[15217.927171]  usb_probe_device+0x34/0x70

stub_disconnect():

[15279.182478] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:908
[15279.182487] in_atomic(): 1, irqs_disabled(): 0, pid: 29114, name: usbip
[15279.182492] 5 locks held by usbip/29114:
[15279.182494]  #0: 0000000091647f28 (sb_writers#6){....}, at: vfs_write+0x191/0x1c0
[15279.182506]  #1: 00000000702cf0f3 (&of->mutex){....}, at: kernfs_fop_write+0xf7/0x1b0
[15279.182514]  #2: 00000000872e5b4b (&dev->mutex){....}, at: __device_driver_lock+0x3b/0x50
[15279.182522]  #3: 00000000e74ececc (&dev->mutex){....}, at: __device_driver_lock+0x46/0x50
[15279.182529]  #4: 00000000b20abbe0 (&(&busid_table[i].busid_lock)->rlock){....}, at: get_busid_priv+0x48/0x60 [usbip_host]
[15279.182541] CPU: 0 PID: 29114 Comm: usbip Tainted: G        W         5.1.0-rc6+ thesofproject#40
[15279.182543] Hardware name: Dell Inc. OptiPlex 790/0HY9JP, BIOS A18 09/24/2013
[15279.182546] Call Trace:
[15279.182554]  dump_stack+0x63/0x85
[15279.182561]  ___might_sleep+0xff/0x120
[15279.182566]  __might_sleep+0x4a/0x80
[15279.182574]  __mutex_lock+0x55/0x950
[15279.182582]  ? get_busid_priv+0x48/0x60 [usbip_host]
[15279.182587]  ? reacquire_held_locks+0xec/0x1a0
[15279.182591]  ? get_busid_priv+0x48/0x60 [usbip_host]
[15279.182597]  ? find_held_lock+0x94/0xa0
[15279.182609]  mutex_lock_nested+0x1b/0x20
[15279.182614]  ? mutex_lock_nested+0x1b/0x20
[15279.182618]  kernfs_remove_by_name_ns+0x2a/0x90
[15279.182625]  sysfs_remove_file_ns+0x15/0x20
[15279.182629]  device_remove_file+0x19/0x20
[15279.182634]  stub_disconnect+0x6d/0x180 [usbip_host]
[15279.182643]  usb_unbind_device+0x27/0x60

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
lyakh pushed a commit that referenced this pull request Jun 17, 2019
Michael Chan says:

===================
bnxt_en: Bug fixes.

There are 4 driver fixes in this series:

1. Fix RX buffer leak during OOM condition.
2. Call pci_disable_msix() under correct conditions to prevent hitting BUG.
3. Reduce unneeded mmeory allocation in kdump kernel to prevent OOM.
4. Don't read device serial number on VFs because it is not supported.

Please queue #1, #2, #3 for -stable as well.  Thanks.
===================

Signed-off-by: David S. Miller <davem@davemloft.net>
lyakh pushed a commit that referenced this pull request Jun 17, 2019
After commit:

  672ff6c ("KVM: x86: Raise #GP when guest vCPU do not support PMU")

my AMD guests started #GPing like this:

  general protection fault: 0000 [#1] PREEMPT SMP
  CPU: 1 PID: 4355 Comm: bash Not tainted 5.1.0-rc6+ #3
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
  RIP: 0010:x86_perf_event_update+0x3b/0xa0

with Code: pointing to RDPMC. It is RDPMC because the guest has the
hardware watchdog CONFIG_HARDLOCKUP_DETECTOR_PERF enabled which uses
perf. Instrumenting kvm_pmu_rdpmc() some, showed that it fails due to:

  if (!pmu->version)
  	return 1;

which the above commit added. Since AMD's PMU leaves the version at 0,
that causes the #GP injection into the guest.

Set pmu->version arbitrarily to 1 and move it above the non-applicable
struct kvm_pmu members.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Cc: kvm@vger.kernel.org
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Mihai Carabas <mihai.carabas@oracle.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org
Cc: stable@vger.kernel.org
Fixes: 672ff6c ("KVM: x86: Raise #GP when guest vCPU do not support PMU")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
lyakh pushed a commit that referenced this pull request Jun 17, 2019
…emove

With this early return due to zfcp_unit child(ren), we don't use the
zfcp_port reference from the earlier zfcp_get_port_by_wwpn() anymore and
need to put it.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: d99b601 ("[SCSI] zfcp: restore refcount check on port_remove")
Cc: <stable@vger.kernel.org> #3.7+
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
lyakh pushed a commit that referenced this pull request Jul 3, 2019
struct dfl_feature_platform_data (and it's mutex) is used
by both fme and port devices, and when lockdep is enabled it
complains about nesting between these locks.  Tell lockdep about
the difference so it can track each class separately.

Here's the lockdep complaint:
[  409.680668] WARNING: possible recursive locking detected
[  409.685983] 5.1.0-rc3.fpga+ #1 Tainted: G            E
[  409.691469] --------------------------------------------
[  409.696779] fpgaconf/9348 is trying to acquire lock:
[  409.701746] 00000000a443fe2e (&pdata->lock){+.+.}, at: port_enable_set+0x24/0x60 [dfl_afu]
[  409.710006]
[  409.710006] but task is already holding lock:
[  409.715837] 0000000063b78782 (&pdata->lock){+.+.}, at: fme_pr_ioctl+0x21d/0x330 [dfl_fme]
[  409.724012]
[  409.724012] other info that might help us debug this:
[  409.730535]  Possible unsafe locking scenario:
[  409.730535]
[  409.736457]        CPU0
[  409.738910]        ----
[  409.741360]   lock(&pdata->lock);
[  409.744679]   lock(&pdata->lock);
[  409.747999]
[  409.747999]  *** DEADLOCK ***
[  409.747999]
[  409.753920]  May be due to missing lock nesting notation
[  409.753920]
[  409.760704] 4 locks held by fpgaconf/9348:
[  409.764805]  #0: 0000000063b78782 (&pdata->lock){+.+.}, at: fme_pr_ioctl+0x21d/0x330 [dfl_fme]
[  409.773408]  #1: 00000000213c8a66 (&region->mutex){+.+.}, at: fpga_region_program_fpga+0x24/0x200 [fpga_region]
[  409.783489]  #2: 00000000fe63afb9 (&mgr->ref_mutex){+.+.}, at: fpga_mgr_lock+0x15/0x40 [fpga_mgr]
[  409.792354]  #3: 000000000b2285c5 (&bridge->mutex){+.+.}, at: __fpga_bridge_get+0x26/0xa0 [fpga_bridge]
[  409.801740]
[  409.801740] stack backtrace:
[  409.806102] CPU: 45 PID: 9348 Comm: fpgaconf Kdump: loaded Tainted: G            E     5.1.0-rc3.fpga+ #1
[  409.815658] Hardware name: Intel Corporation S2600BT/S2600BT, BIOS SE5C620.86B.01.00.0763.022420181017 02/24/2018
[  409.825911] Call Trace:
[  409.828369]  dump_stack+0x5e/0x8b
[  409.831686]  __lock_acquire+0xf3d/0x10e0
[  409.835612]  ? find_held_lock+0x3c/0xa0
[  409.839451]  lock_acquire+0xbc/0x1d0
[  409.843030]  ? port_enable_set+0x24/0x60 [dfl_afu]
[  409.847823]  ? port_enable_set+0x24/0x60 [dfl_afu]
[  409.852616]  __mutex_lock+0x86/0x970
[  409.856195]  ? port_enable_set+0x24/0x60 [dfl_afu]
[  409.860989]  ? port_enable_set+0x24/0x60 [dfl_afu]
[  409.865777]  ? __mutex_unlock_slowpath+0x4b/0x290
[  409.870486]  port_enable_set+0x24/0x60 [dfl_afu]
[  409.875106]  fpga_bridges_disable+0x36/0x50 [fpga_bridge]
[  409.880502]  fpga_region_program_fpga+0xea/0x200 [fpga_region]
[  409.886338]  fme_pr_ioctl+0x13e/0x330 [dfl_fme]
[  409.890870]  fme_ioctl+0x66/0xe0 [dfl_fme]
[  409.894973]  do_vfs_ioctl+0xa9/0x720
[  409.898548]  ? lockdep_hardirqs_on+0xf0/0x1a0
[  409.902907]  ksys_ioctl+0x60/0x90
[  409.906225]  __x64_sys_ioctl+0x16/0x20
[  409.909981]  do_syscall_64+0x5a/0x220
[  409.913644]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  409.918698] RIP: 0033:0x7f9d31b9b8d7
[  409.922276] Code: 44 00 00 48 8b 05 b9 15 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 89 15 2d 00 f7 d8 64 89 01 48
[  409.941020] RSP: 002b:00007ffe4cae0d68 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[  409.948588] RAX: ffffffffffffffda RBX: 00007f9d32ade6a0 RCX: 00007f9d31b9b8d7
[  409.955719] RDX: 00007ffe4cae0df0 RSI: 000000000000b680 RDI: 0000000000000003
[  409.962852] RBP: 0000000000000003 R08: 00007f9d2b70a177 R09: 00007ffe4cae0e40
[  409.969984] R10: 00007ffe4cae0160 R11: 0000000000000202 R12: 00007ffe4cae0df0
[  409.977115] R13: 000000000000b680 R14: 0000000000000000 R15: 00007ffe4cae0f60

Signed-off-by: Scott Wood <swood@redhat.com>
Acked-by: Wu Hao <hao.wu@intel.com>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
lyakh pushed a commit that referenced this pull request Jul 3, 2019
ifmsh->csa is an RCU-protected pointer. The writer context
in ieee80211_mesh_finish_csa() is already mutually
exclusive with wdev->sdata.mtx, but the RCU checker did
not know this. Use rcu_dereference_protected() to avoid a
warning.

fixes the following warning:

[   12.519089] =============================
[   12.520042] WARNING: suspicious RCU usage
[   12.520652] 5.1.0-rc7-wt+ thesofproject#16 Tainted: G        W
[   12.521409] -----------------------------
[   12.521972] net/mac80211/mesh.c:1223 suspicious rcu_dereference_check() usage!
[   12.522928] other info that might help us debug this:
[   12.523984] rcu_scheduler_active = 2, debug_locks = 1
[   12.524855] 5 locks held by kworker/u8:2/152:
[   12.525438]  #0: 00000000057be08c ((wq_completion)phy0){+.+.}, at: process_one_work+0x1a2/0x620
[   12.526607]  #1: 0000000059c6b07a ((work_completion)(&sdata->csa_finalize_work)){+.+.}, at: process_one_work+0x1a2/0x620
[   12.528001]  #2: 00000000f184ba7d (&wdev->mtx){+.+.}, at: ieee80211_csa_finalize_work+0x2f/0x90
[   12.529116]  #3: 00000000831a1f54 (&local->mtx){+.+.}, at: ieee80211_csa_finalize_work+0x47/0x90
[   12.530233]  #4: 00000000fd06f988 (&local->chanctx_mtx){+.+.}, at: ieee80211_csa_finalize_work+0x51/0x90

Signed-off-by: Thomas Pedersen <thomas@eero.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
lyakh pushed a commit that referenced this pull request Jul 3, 2019
…utex

Remove circular lock dependency by using atomic version of interfaces
iterate in watch_dog_work(), hence avoid taking local->iflist_mtx
(rtw_vif_watch_dog_iter() only update some data, it can be called from
atomic context). Fixes below LOCKDEP warning:

[ 1157.219415] ======================================================
[ 1157.225772] [ INFO: possible circular locking dependency detected ]
[ 1157.232150] 3.10.0-1043.el7.sgruszka1.x86_64.debug #1 Not tainted
[ 1157.238346] -------------------------------------------------------
[ 1157.244635] kworker/u4:2/14490 is trying to acquire lock:
[ 1157.250194]  (&rtwdev->mutex){+.+.+.}, at: [<ffffffffc098322b>] rtw_ops_config+0x2b/0x90 [rtw88]
[ 1157.259151]
but task is already holding lock:
[ 1157.265085]  (&local->iflist_mtx){+.+...}, at: [<ffffffffc0b8ab7a>] ieee80211_mgd_probe_ap.part.28+0xca/0x160 [mac80211]
[ 1157.276169]
which lock already depends on the new lock.

[ 1157.284488]
the existing dependency chain (in reverse order) is:
[ 1157.292101]
-> #2 (&local->iflist_mtx){+.+...}:
[ 1157.296919]        [<ffffffffbc741a29>] lock_acquire+0x99/0x1e0
[ 1157.302955]        [<ffffffffbce72793>] mutex_lock_nested+0x93/0x410
[ 1157.309416]        [<ffffffffc0b6038f>] ieee80211_iterate_interfaces+0x2f/0x60 [mac80211]
[ 1157.317730]        [<ffffffffc09811ab>] rtw_watch_dog_work+0xcb/0x130 [rtw88]
[ 1157.325003]        [<ffffffffbc6d77bc>] process_one_work+0x22c/0x720
[ 1157.331481]        [<ffffffffbc6d7dd6>] worker_thread+0x126/0x3b0
[ 1157.337589]        [<ffffffffbc6e107f>] kthread+0xef/0x100
[ 1157.343260]        [<ffffffffbce848b7>] ret_from_fork_nospec_end+0x0/0x39
[ 1157.350091]
-> #1 ((&(&rtwdev->watch_dog_work)->work)){+.+...}:
[ 1157.356314]        [<ffffffffbc741a29>] lock_acquire+0x99/0x1e0
[ 1157.362427]        [<ffffffffbc6d570b>] flush_work+0x5b/0x310
[ 1157.368287]        [<ffffffffbc6d740e>] __cancel_work_timer+0xae/0x170
[ 1157.374940]        [<ffffffffbc6d7583>] cancel_delayed_work_sync+0x13/0x20
[ 1157.381930]        [<ffffffffc0982b49>] rtw_core_stop+0x29/0x50 [rtw88]
[ 1157.388679]        [<ffffffffc098bee6>] rtw_enter_ips+0x16/0x20 [rtw88]
[ 1157.395428]        [<ffffffffc0983242>] rtw_ops_config+0x42/0x90 [rtw88]
[ 1157.402173]        [<ffffffffc0b13343>] ieee80211_hw_config+0xc3/0x680 [mac80211]
[ 1157.409854]        [<ffffffffc0b3925b>] ieee80211_do_open+0x69b/0x9c0 [mac80211]
[ 1157.417418]        [<ffffffffc0b395e9>] ieee80211_open+0x69/0x70 [mac80211]
[ 1157.424496]        [<ffffffffbcd03442>] __dev_open+0xe2/0x160
[ 1157.430356]        [<ffffffffbcd03773>] __dev_change_flags+0xa3/0x180
[ 1157.436922]        [<ffffffffbcd03879>] dev_change_flags+0x29/0x60
[ 1157.443224]        [<ffffffffbcda14c4>] devinet_ioctl+0x794/0x890
[ 1157.449331]        [<ffffffffbcda27b5>] inet_ioctl+0x75/0xa0
[ 1157.455087]        [<ffffffffbccd54eb>] sock_do_ioctl+0x2b/0x60
[ 1157.461178]        [<ffffffffbccd5753>] sock_ioctl+0x233/0x310
[ 1157.467109]        [<ffffffffbc8bd820>] do_vfs_ioctl+0x410/0x6c0
[ 1157.473233]        [<ffffffffbc8bdb71>] SyS_ioctl+0xa1/0xc0
[ 1157.478914]        [<ffffffffbce84a5e>] system_call_fastpath+0x25/0x2a
[ 1157.485569]
-> #0 (&rtwdev->mutex){+.+.+.}:
[ 1157.490022]        [<ffffffffbc7409d1>] __lock_acquire+0xec1/0x1630
[ 1157.496305]        [<ffffffffbc741a29>] lock_acquire+0x99/0x1e0
[ 1157.502413]        [<ffffffffbce72793>] mutex_lock_nested+0x93/0x410
[ 1157.508890]        [<ffffffffc098322b>] rtw_ops_config+0x2b/0x90 [rtw88]
[ 1157.515724]        [<ffffffffc0b13343>] ieee80211_hw_config+0xc3/0x680 [mac80211]
[ 1157.523370]        [<ffffffffc0b8a4ca>] ieee80211_recalc_ps.part.27+0x9a/0x180 [mac80211]
[ 1157.531685]        [<ffffffffc0b8abc5>] ieee80211_mgd_probe_ap.part.28+0x115/0x160 [mac80211]
[ 1157.540353]        [<ffffffffc0b8b40d>] ieee80211_beacon_connection_loss_work+0x4d/0x80 [mac80211]
[ 1157.549513]        [<ffffffffbc6d77bc>] process_one_work+0x22c/0x720
[ 1157.555886]        [<ffffffffbc6d7dd6>] worker_thread+0x126/0x3b0
[ 1157.562170]        [<ffffffffbc6e107f>] kthread+0xef/0x100
[ 1157.567765]        [<ffffffffbce848b7>] ret_from_fork_nospec_end+0x0/0x39
[ 1157.574579]
other info that might help us debug this:

[ 1157.582788] Chain exists of:
  &rtwdev->mutex --> (&(&rtwdev->watch_dog_work)->work) --> &local->iflist_mtx

[ 1157.593024]  Possible unsafe locking scenario:

[ 1157.599046]        CPU0                    CPU1
[ 1157.603653]        ----                    ----
[ 1157.608258]   lock(&local->iflist_mtx);
[ 1157.612180]                                lock((&(&rtwdev->watch_dog_work)->work));
[ 1157.620074]                                lock(&local->iflist_mtx);
[ 1157.626555]   lock(&rtwdev->mutex);
[ 1157.630124]
 *** DEADLOCK ***

[ 1157.636148] 4 locks held by kworker/u4:2/14490:
[ 1157.640755]  #0:  (%s#6){.+.+.+}, at: [<ffffffffbc6d774a>] process_one_work+0x1ba/0x720
[ 1157.648965]  #1:  ((&ifmgd->beacon_connection_loss_work)){+.+.+.}, at: [<ffffffffbc6d774a>] process_one_work+0x1ba/0x720
[ 1157.659950]  #2:  (&wdev->mtx){+.+.+.}, at: [<ffffffffc0b8aad5>] ieee80211_mgd_probe_ap.part.28+0x25/0x160 [mac80211]
[ 1157.670901]  #3:  (&local->iflist_mtx){+.+...}, at: [<ffffffffc0b8ab7a>] ieee80211_mgd_probe_ap.part.28+0xca/0x160 [mac80211]
[ 1157.682466]

Fixes: e303748 ("rtw88: new Realtek 802.11ac driver")
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
lyakh pushed a commit that referenced this pull request Jul 3, 2019
There was the below bug report from Wu Fangsuo.

On the CMA allocation path, isolate_migratepages_range() could isolate
unevictable LRU pages and reclaim_clean_page_from_list() can try to
reclaim them if they are clean file-backed pages.

  page:ffffffbf02f33b40 count:86 mapcount:84 mapping:ffffffc08fa7a810 index:0x24
  flags: 0x19040c(referenced|uptodate|arch_1|mappedtodisk|unevictable|mlocked)
  raw: 000000000019040c ffffffc08fa7a810 0000000000000024 0000005600000053
  raw: ffffffc009b05b20 ffffffc009b05b20 0000000000000000 ffffffc09bf3ee80
  page dumped because: VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page))
  page->mem_cgroup:ffffffc09bf3ee80
  ------------[ cut here ]------------
  kernel BUG at /home/build/farmland/adroid9.0/kernel/linux/mm/vmscan.c:1350!
  Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 0 PID: 7125 Comm: syz-executor Tainted: G S              4.14.81 #3
  Hardware name: ASR AQUILAC EVB (DT)
  task: ffffffc00a54cd00 task.stack: ffffffc009b00000
  PC is at shrink_page_list+0x1998/0x3240
  LR is at shrink_page_list+0x1998/0x3240
  pc : [<ffffff90083a2158>] lr : [<ffffff90083a2158>] pstate: 60400045
  sp : ffffffc009b05940
  ..
     shrink_page_list+0x1998/0x3240
     reclaim_clean_pages_from_list+0x3c0/0x4f0
     alloc_contig_range+0x3bc/0x650
     cma_alloc+0x214/0x668
     ion_cma_allocate+0x98/0x1d8
     ion_alloc+0x200/0x7e0
     ion_ioctl+0x18c/0x378
     do_vfs_ioctl+0x17c/0x1780
     SyS_ioctl+0xac/0xc0

Wu found it's due to commit ad6b670 ("mm: remove SWAP_MLOCK in
ttu").  Before that, unevictable pages go to cull_mlocked so that we
can't reach the VM_BUG_ON_PAGE line.

To fix the issue, this patch filters out unevictable LRU pages from the
reclaim_clean_pages_from_list in CMA.

Link: http://lkml.kernel.org/r/20190524071114.74202-1-minchan@kernel.org
Fixes: ad6b670 ("mm: remove SWAP_MLOCK in ttu")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Wu Fangsuo <fangsuowu@asrmicro.com>
Debugged-by: Wu Fangsuo <fangsuowu@asrmicro.com>
Tested-by: Wu Fangsuo <fangsuowu@asrmicro.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Pankaj Suryawanshi <pankaj.suryawanshi@einfochips.com>
Cc: <stable@vger.kernel.org>	[4.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lyakh pushed a commit that referenced this pull request Jul 3, 2019
Commit c1fe190 ("powerpc: Add force enable of DAWR on P9 option")
screwed up some assembler and corrupted a pointer in r3. This resulted
in crashes like the below:

  BUG: Kernel NULL pointer dereference at 0x000013bf
  Faulting instruction address: 0xc00000000010b044
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  CPU: 8 PID: 1771 Comm: qemu-system-ppc Kdump: loaded Not tainted 5.2.0-rc4+ #3
  NIP:  c00000000010b044 LR: c0080000089dacf4 CTR: c00000000010aff4
  REGS: c00000179b397710 TRAP: 0300   Not tainted  (5.2.0-rc4+)
  MSR:  800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 42244842  XER: 00000000
  CFAR: c00000000010aff8 DAR: 00000000000013bf DSISR: 42000000 IRQMASK: 0
  GPR00: c0080000089dd6bc c00000179b3979a0 c008000008a04300 ffffffffffffffff
  GPR04: 0000000000000000 0000000000000003 000000002444b05d c0000017f11c45d0
  ...
  NIP kvmppc_h_set_dabr+0x50/0x68
  LR  kvmppc_pseries_do_hcall+0xa3c/0xeb0 [kvm_hv]
  Call Trace:
    0xc0000017f11c0000 (unreliable)
    kvmppc_vcpu_run_hv+0x694/0xec0 [kvm_hv]
    kvmppc_vcpu_run+0x34/0x48 [kvm]
    kvm_arch_vcpu_ioctl_run+0x2f4/0x400 [kvm]
    kvm_vcpu_ioctl+0x460/0x850 [kvm]
    do_vfs_ioctl+0xe4/0xb40
    ksys_ioctl+0xc4/0x110
    sys_ioctl+0x28/0x80
    system_call+0x5c/0x70
  Instruction dump:
  4082fff4 4c00012c 38600000 4e800020 e96280c0 896b0000 2c2b0000 3860ffff
  4d820020 50852e74 508516f6 78840724 <f88313c0> f8a313c8 7c942ba6 7cbc2ba6

Fix the bug by only changing r3 when we are returning immediately.

Fixes: c1fe190 ("powerpc: Add force enable of DAWR on P9 option")
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reported-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
lyakh pushed a commit that referenced this pull request Jul 3, 2019
KMSAN caught uninit-value in tcp_create_openreq_child() [1]
This is caused by a recent change, combined by the fact
that TCP cleared num_timeout, num_retrans and sk fields only
when a request socket was about to be queued.

Under syncookie mode, a temporary request socket is used,
and req->num_timeout could contain garbage.

Lets clear these three fields sooner, there is really no
point trying to defer this and risk other bugs.

[1]

BUG: KMSAN: uninit-value in tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526
CPU: 1 PID: 13357 Comm: syz-executor591 Not tainted 5.2.0-rc4+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x191/0x1f0 lib/dump_stack.c:113
 kmsan_report+0x162/0x2d0 mm/kmsan/kmsan.c:611
 __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:304
 tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526
 tcp_v6_syn_recv_sock+0x761/0x2d80 net/ipv6/tcp_ipv6.c:1152
 tcp_get_cookie_sock+0x16e/0x6b0 net/ipv4/syncookies.c:209
 cookie_v6_check+0x27e0/0x29a0 net/ipv6/syncookies.c:252
 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline]
 tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344
 tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554
 ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397
 ip6_input_finish net/ipv6/ip6_input.c:438 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447
 dst_input include/net/dst.h:439 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272
 __netif_receive_skb_one_core net/core/dev.c:4981 [inline]
 __netif_receive_skb net/core/dev.c:5095 [inline]
 process_backlog+0x721/0x1410 net/core/dev.c:5906
 napi_poll net/core/dev.c:6329 [inline]
 net_rx_action+0x738/0x1940 net/core/dev.c:6395
 __do_softirq+0x4ad/0x858 kernel/softirq.c:293
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
 </IRQ>
 do_softirq kernel/softirq.c:338 [inline]
 __local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline]
 ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117
 ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167
 dst_output include/net/dst.h:433 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271
 inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156
 tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline]
 tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397
 __tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573
 tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118
 tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403
 inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427
 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470
 __sock_release net/socket.c:601 [inline]
 sock_close+0x156/0x490 net/socket.c:1273
 __fput+0x4c9/0xba0 fs/file_table.c:280
 ____fput+0x37/0x40 fs/file_table.c:313
 task_work_run+0x22e/0x2a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:185 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:168 [inline]
 prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199
 syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279
 do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x401d50
Code: 01 f0 ff ff 0f 83 40 0d 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d dd 8d 2d 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 14 0d 00 00 c3 48 83 ec 08 e8 7a 02 00 00
RSP: 002b:00007fff1cf58cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000401d50
RDX: 000000000000001c RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000004a9050 R08: 0000000020000040 R09: 000000000000001c
R10: 0000000020004004 R11: 0000000000000246 R12: 0000000000402ef0
R13: 0000000000402f80 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:201 [inline]
 kmsan_internal_poison_shadow+0x53/0xa0 mm/kmsan/kmsan.c:160
 kmsan_kmalloc+0xa4/0x130 mm/kmsan/kmsan_hooks.c:177
 kmem_cache_alloc+0x534/0xb00 mm/slub.c:2781
 reqsk_alloc include/net/request_sock.h:84 [inline]
 inet_reqsk_alloc+0xa8/0x600 net/ipv4/tcp_input.c:6384
 cookie_v6_check+0xadb/0x29a0 net/ipv6/syncookies.c:173
 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline]
 tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344
 tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554
 ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397
 ip6_input_finish net/ipv6/ip6_input.c:438 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447
 dst_input include/net/dst.h:439 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272
 __netif_receive_skb_one_core net/core/dev.c:4981 [inline]
 __netif_receive_skb net/core/dev.c:5095 [inline]
 process_backlog+0x721/0x1410 net/core/dev.c:5906
 napi_poll net/core/dev.c:6329 [inline]
 net_rx_action+0x738/0x1940 net/core/dev.c:6395
 __do_softirq+0x4ad/0x858 kernel/softirq.c:293
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
 do_softirq kernel/softirq.c:338 [inline]
 __local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline]
 ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117
 ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167
 dst_output include/net/dst.h:433 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271
 inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156
 tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline]
 tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397
 __tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573
 tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118
 tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403
 inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427
 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470
 __sock_release net/socket.c:601 [inline]
 sock_close+0x156/0x490 net/socket.c:1273
 __fput+0x4c9/0xba0 fs/file_table.c:280
 ____fput+0x37/0x40 fs/file_table.c:313
 task_work_run+0x22e/0x2a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:185 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:168 [inline]
 prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199
 syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279
 do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Fixes: 336c39a ("tcp: undo init congestion window on false SYNACK timeout")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
lyakh pushed a commit that referenced this pull request Jan 8, 2020
As virtual_context_destroy() may be called from a request signal, it may
be called from inside an irq-off section, and so we need to do a full
save/restore of the irq state rather than blindly re-enable irqs upon
unlocking.

<4> [110.024262] WARNING: inconsistent lock state
<4> [110.024277] 5.4.0-rc8-CI-CI_DRM_7489+ #1 Tainted: G     U
<4> [110.024292] --------------------------------
<4> [110.024305] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
<4> [110.024323] kworker/0:0/5 [HC0[0]:SC0[0]:HE1:SE1] takes:
<4> [110.024338] ffff88826a0c7a18 (&(&rq->lock)->rlock){?.-.}, at: i915_request_retire+0x221/0x930 [i915]
<4> [110.024592] {IN-HARDIRQ-W} state was registered at:
<4> [110.024612]   lock_acquire+0xa7/0x1c0
<4> [110.024627]   _raw_spin_lock_irqsave+0x33/0x50
<4> [110.024788]   intel_engine_breadcrumbs_irq+0x38c/0x600 [i915]
<4> [110.024808]   irq_work_run_list+0x49/0x70
<4> [110.024824]   irq_work_run+0x26/0x50
<4> [110.024839]   smp_irq_work_interrupt+0x44/0x1e0
<4> [110.024855]   irq_work_interrupt+0xf/0x20
<4> [110.024871]   __do_softirq+0xb7/0x47f
<4> [110.024885]   irq_exit+0xba/0xc0
<4> [110.024898]   do_IRQ+0x83/0x160
<4> [110.024910]   ret_from_intr+0x0/0x1d
<4> [110.024922] irq event stamp: 172864
<4> [110.024938] hardirqs last  enabled at (172863): [<ffffffff819ea214>] _raw_spin_unlock_irq+0x24/0x50
<4> [110.024963] hardirqs last disabled at (172864): [<ffffffff819e9fba>] _raw_spin_lock_irq+0xa/0x40
<4> [110.024988] softirqs last  enabled at (172812): [<ffffffff81c00385>] __do_softirq+0x385/0x47f
<4> [110.025012] softirqs last disabled at (172797): [<ffffffff810b829a>] irq_exit+0xba/0xc0
<4> [110.025031]
other info that might help us debug this:
<4> [110.025049]  Possible unsafe locking scenario:

<4> [110.025065]        CPU0
<4> [110.025075]        ----
<4> [110.025084]   lock(&(&rq->lock)->rlock);
<4> [110.025099]   <Interrupt>
<4> [110.025109]     lock(&(&rq->lock)->rlock);
<4> [110.025124]
 *** DEADLOCK ***

<4> [110.025144] 4 locks held by kworker/0:0/5:
<4> [110.025156]  #0: ffff88827588f528 ((wq_completion)events){+.+.}, at: process_one_work+0x1de/0x620
<4> [110.025187]  #1: ffffc9000006fe78 ((work_completion)(&engine->retire_work)){+.+.}, at: process_one_work+0x1de/0x620
<4> [110.025219]  #2: ffff88825605e270 (&kernel#2){+.+.}, at: engine_retire+0x57/0xe0 [i915]
<4> [110.025405]  #3: ffff88826a0c7a18 (&(&rq->lock)->rlock){?.-.}, at: i915_request_retire+0x221/0x930 [i915]
<4> [110.025634]
stack backtrace:
<4> [110.025653] CPU: 0 PID: 5 Comm: kworker/0:0 Tainted: G     U            5.4.0-rc8-CI-CI_DRM_7489+ #1
<4> [110.025675] Hardware name:  /NUC7i5BNB, BIOS BNKBL357.86A.0054.2017.1025.1822 10/25/2017
<4> [110.025856] Workqueue: events engine_retire [i915]
<4> [110.025872] Call Trace:
<4> [110.025891]  dump_stack+0x71/0x9b
<4> [110.025907]  mark_lock+0x49a/0x500
<4> [110.025926]  ? print_shortest_lock_dependencies+0x200/0x200
<4> [110.025946]  mark_held_locks+0x49/0x70
<4> [110.025962]  ? _raw_spin_unlock_irq+0x24/0x50
<4> [110.025978]  lockdep_hardirqs_on+0xa2/0x1c0
<4> [110.025995]  _raw_spin_unlock_irq+0x24/0x50
<4> [110.026171]  virtual_context_destroy+0xc5/0x2e0 [i915]
<4> [110.026376]  __active_retire+0xb4/0x290 [i915]
<4> [110.026396]  dma_fence_signal_locked+0x9e/0x1b0
<4> [110.026613]  i915_request_retire+0x451/0x930 [i915]
<4> [110.026766]  retire_requests+0x4d/0x60 [i915]
<4> [110.026919]  engine_retire+0x63/0xe0 [i915]

Fixes: b1e3177 ("drm/i915: Coordinate i915_active with its own mutex")
Fixes: 6d06779 ("drm/i915: Load balancing across a virtual engine")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191205145934.663183-1-chris@chris-wilson.co.uk
(cherry picked from commit 6f7ac82)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
lyakh pushed a commit that referenced this pull request Jan 8, 2020
The current rbtree for service ranges in the name table is built based
on the 'lower' & 'upper' range values resulting in a flaw in the rbtree
searching. Some issues have been observed in case of range overlapping:

Case #1: unable to withdraw a name entry:
After some name services are bound, all of them are withdrawn by user
but one remains in the name table forever. This corrupts the table and
that service becomes dummy i.e. no real port.
E.g.

                /
           {22, 22}
              /
             /
   --->  {10, 50}
           /  \
          /    \
    {10, 30}  {20, 60}

The node {10, 30} cannot be removed since the rbtree searching stops at
the node's ancestor i.e. {10, 50}, so starting from it will never reach
the finding node.

Case #2: failed to send data in some cases:
E.g. Two service ranges: {20, 60}, {10, 50} are bound. The rbtree for
this service will be one of the two cases below depending on the order
of the bindings:

        {20, 60}             {10, 50} <--
          /  \                 /  \
         /    \               /    \
    {10, 50}  NIL <--       NIL  {20, 60}

          (a)                    (b)

Now, try to send some data to service {30}, there will be two results:
(a): Failed, no route to host.
(b): Ok.

The reason is that the rbtree searching will stop at the pointing node
as shown above.

Case #3: Same as case #2b above but if the data sending's scope is
local and the {10, 50} is published by a peer node, then it will result
in 'no route to host' even though the other {20, 60} is for example on
the local node which should be able to get the data.

The issues are actually due to the way we built the rbtree. This commit
fixes it by introducing an additional field to each node - named 'max',
which is the largest 'upper' of that node subtree. The 'max' value for
each subtrees will be propagated correctly whenever a node is inserted/
removed or the tree is rebalanced by the augmented rbtree callbacks.

By this way, we can change the rbtree searching appoarch to solve the
issues above. Another benefit from this is that we can now improve the
searching for a next range matching e.g. in case of multicast, so get
rid of the unneeded looping over all nodes in the tree.

Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
lyakh pushed a commit that referenced this pull request Jan 8, 2020
…nces

The Slave device initialization can be split in 4 different cases:

1. Master-initiated hardware reset, system suspend-resume and
pm_runtime based on clock-stop mode1. To avoid timeouts and a bad
audio experience, the Slave device resume operations need to wait for
the Slave device to be re-enumerated and its settings restored.

2. Exit from clock-stop mode0. In this case, the Slave device is
required to remain enumerated and its context preserved while the
clock is stopped, so no re-initialization or wait_for_completion() is
necessary.

3. Slave-initiated pm_runtime D3 transition. With the parent child
relationship, it is possible that a Slave device becomes 'suspended'
while its parent is still 'active' with the bus clock still
toggling. In this case, during the pm_runtime resume operation, there
is no need to wait for any settings to be restored.

4. Slave reset (sync loss or implementation-defined). In that case the
bus remains operational and the Slave device will be re-initialized
when it becomes ATTACHED again.

In previous patches, we suggested the use of wait_for_completion() to
deal with the case #1, but case #2 and #3 do not need any wait.

To account for those differences, this patch adds an unattach_request
field. The field is explicitly set by the Master for the case #1, and
if non-zero the Slave device shall wait on resume. In all other cases,
the Slave resume operations can proceed without wait.

The only request tracked so far is Master HardReset, but the request
is declared as a bit mask for future extensions (if needed). The
definition for this value is added in bus.h and does not need to be
exposed in sdw.h

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20191212014507.28050-5-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
lyakh pushed a commit that referenced this pull request Jan 8, 2020
We got another syzbot report [1] that tells us we must use
write_lock_irq()/write_unlock_irq() to avoid possible deadlock.

[1]

WARNING: inconsistent lock state
5.5.0-rc1-syzkaller #0 Not tainted
--------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-R} usage.
syz-executor826/9605 [HC1[1]:SC0[0]:HE0:SE1] takes:
ffffffff8a128718 (disc_data_lock){+-..}, at: sp_get.isra.0+0x1d/0xf0 drivers/net/ppp/ppp_synctty.c:138
{HARDIRQ-ON-W} state was registered at:
  lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
  __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
  _raw_write_lock_bh+0x33/0x50 kernel/locking/spinlock.c:319
  sixpack_close+0x1d/0x250 drivers/net/hamradio/6pack.c:657
  tty_ldisc_close.isra.0+0x119/0x1a0 drivers/tty/tty_ldisc.c:489
  tty_set_ldisc+0x230/0x6b0 drivers/tty/tty_ldisc.c:585
  tiocsetd drivers/tty/tty_io.c:2337 [inline]
  tty_ioctl+0xe8d/0x14f0 drivers/tty/tty_io.c:2597
  vfs_ioctl fs/ioctl.c:47 [inline]
  file_ioctl fs/ioctl.c:545 [inline]
  do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732
  ksys_ioctl+0xab/0xd0 fs/ioctl.c:749
  __do_sys_ioctl fs/ioctl.c:756 [inline]
  __se_sys_ioctl fs/ioctl.c:754 [inline]
  __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754
  do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
irq event stamp: 3946
hardirqs last  enabled at (3945): [<ffffffff87c86e43>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
hardirqs last  enabled at (3945): [<ffffffff87c86e43>] _raw_spin_unlock_irq+0x23/0x80 kernel/locking/spinlock.c:199
hardirqs last disabled at (3946): [<ffffffff8100675f>] trace_hardirqs_off_thunk+0x1a/0x1c arch/x86/entry/thunk_64.S:42
softirqs last  enabled at (2658): [<ffffffff86a8b4df>] spin_unlock_bh include/linux/spinlock.h:383 [inline]
softirqs last  enabled at (2658): [<ffffffff86a8b4df>] clusterip_netdev_event+0x46f/0x670 net/ipv4/netfilter/ipt_CLUSTERIP.c:222
softirqs last disabled at (2656): [<ffffffff86a8b22b>] spin_lock_bh include/linux/spinlock.h:343 [inline]
softirqs last disabled at (2656): [<ffffffff86a8b22b>] clusterip_netdev_event+0x1bb/0x670 net/ipv4/netfilter/ipt_CLUSTERIP.c:196

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(disc_data_lock);
  <Interrupt>
    lock(disc_data_lock);

 *** DEADLOCK ***

5 locks held by syz-executor826/9605:
 #0: ffff8880a905e198 (&tty->legacy_mutex){+.+.}, at: tty_lock+0xc7/0x130 drivers/tty/tty_mutex.c:19
 #1: ffffffff899a56c0 (rcu_read_lock){....}, at: mutex_spin_on_owner+0x0/0x330 kernel/locking/mutex.c:413
 #2: ffff8880a496a2b0 (&(&i->lock)->rlock){-.-.}, at: spin_lock include/linux/spinlock.h:338 [inline]
 #2: ffff8880a496a2b0 (&(&i->lock)->rlock){-.-.}, at: serial8250_interrupt+0x2d/0x1a0 drivers/tty/serial/8250/8250_core.c:116
 #3: ffffffff8c104048 (&port_lock_key){-.-.}, at: serial8250_handle_irq.part.0+0x24/0x330 drivers/tty/serial/8250/8250_port.c:1823
 #4: ffff8880a905e090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref+0x22/0x90 drivers/tty/tty_ldisc.c:288

stack backtrace:
CPU: 1 PID: 9605 Comm: syz-executor826 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 print_usage_bug.cold+0x327/0x378 kernel/locking/lockdep.c:3101
 valid_state kernel/locking/lockdep.c:3112 [inline]
 mark_lock_irq kernel/locking/lockdep.c:3309 [inline]
 mark_lock+0xbb4/0x1220 kernel/locking/lockdep.c:3666
 mark_usage kernel/locking/lockdep.c:3554 [inline]
 __lock_acquire+0x1e55/0x4a00 kernel/locking/lockdep.c:3909
 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
 _raw_read_lock+0x32/0x50 kernel/locking/spinlock.c:223
 sp_get.isra.0+0x1d/0xf0 drivers/net/ppp/ppp_synctty.c:138
 sixpack_write_wakeup+0x25/0x340 drivers/net/hamradio/6pack.c:402
 tty_wakeup+0xe9/0x120 drivers/tty/tty_io.c:536
 tty_port_default_wakeup+0x2b/0x40 drivers/tty/tty_port.c:50
 tty_port_tty_wakeup+0x57/0x70 drivers/tty/tty_port.c:387
 uart_write_wakeup+0x46/0x70 drivers/tty/serial/serial_core.c:104
 serial8250_tx_chars+0x495/0xaf0 drivers/tty/serial/8250/8250_port.c:1761
 serial8250_handle_irq.part.0+0x2a2/0x330 drivers/tty/serial/8250/8250_port.c:1834
 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1820 [inline]
 serial8250_default_handle_irq+0xc0/0x150 drivers/tty/serial/8250/8250_port.c:1850
 serial8250_interrupt+0xf1/0x1a0 drivers/tty/serial/8250/8250_core.c:126
 __handle_irq_event_percpu+0x15d/0x970 kernel/irq/handle.c:149
 handle_irq_event_percpu+0x74/0x160 kernel/irq/handle.c:189
 handle_irq_event+0xa7/0x134 kernel/irq/handle.c:206
 handle_edge_irq+0x25e/0x8d0 kernel/irq/chip.c:830
 generic_handle_irq_desc include/linux/irqdesc.h:156 [inline]
 do_IRQ+0xde/0x280 arch/x86/kernel/irq.c:250
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:607
 </IRQ>
RIP: 0010:cpu_relax arch/x86/include/asm/processor.h:685 [inline]
RIP: 0010:mutex_spin_on_owner+0x247/0x330 kernel/locking/mutex.c:579
Code: c3 be 08 00 00 00 4c 89 e7 e8 e5 06 59 00 4c 89 e0 48 c1 e8 03 42 80 3c 38 00 0f 85 e1 00 00 00 49 8b 04 24 a8 01 75 96 f3 90 <e9> 2f fe ff ff 0f 0b e8 0d 19 09 00 84 c0 0f 85 ff fd ff ff 48 c7
RSP: 0018:ffffc90001eafa20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffd7
RAX: 0000000000000000 RBX: ffff88809fd9e0c0 RCX: 1ffffffff13266dd
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
RBP: ffffc90001eafa60 R08: 1ffff11013d22898 R09: ffffed1013d22899
R10: ffffed1013d22898 R11: ffff88809e9144c7 R12: ffff8880a905e138
R13: ffff88809e9144c0 R14: 0000000000000000 R15: dffffc0000000000
 mutex_optimistic_spin kernel/locking/mutex.c:673 [inline]
 __mutex_lock_common kernel/locking/mutex.c:962 [inline]
 __mutex_lock+0x32b/0x13c0 kernel/locking/mutex.c:1106
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1121
 tty_lock+0xc7/0x130 drivers/tty/tty_mutex.c:19
 tty_release+0xb5/0xe90 drivers/tty/tty_io.c:1665
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x8e7/0x2ef0 kernel/exit.c:797
 do_group_exit+0x135/0x360 kernel/exit.c:895
 __do_sys_exit_group kernel/exit.c:906 [inline]
 __se_sys_exit_group kernel/exit.c:904 [inline]
 __x64_sys_exit_group+0x44/0x50 kernel/exit.c:904
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x43fef8
Code: Bad RIP value.
RSP: 002b:00007ffdb07d2338 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043fef8
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004bf730 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000

Fixes: 6e4e2f8 ("6pack,mkiss: fix lock inconsistency")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
lyakh pushed a commit that referenced this pull request Feb 3, 2020
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 <davem@davemloft.net>
lyakh pushed a commit that referenced this pull request Feb 3, 2020
We would not be transmitting using the correct SYSTEMPORT transmit queue
during ndo_select_queue() which looks up the internal TX ring map
because while establishing the mapping we would be off by 4, so for
instance, when we populate switch port mappings we would be doing:

switch port 0, queue 0 -> ring index #0
switch port 0, queue 1 -> ring index #1
...
switch port 0, queue 3 -> ring index #3
switch port 1, queue 0 -> ring index thesofproject#8 (4 + 4 * 1)
...

instead of using ring index #4. This would cause our ndo_select_queue()
to use the fallback queue mechanism which would pick up an incorrect
ring for that switch port. Fix this by using the correct switch queue
number instead of SYSTEMPORT queue number.

Fixes: 25c4407 ("net: systemport: Simplify queue mapping logic")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
lyakh pushed a commit that referenced this pull request Mar 13, 2020
I see the following lockdep splat in the qcom pinctrl driver when
attempting to suspend the device.

 WARNING: possible recursive locking detected
 5.4.11 #3 Tainted: G        W
 --------------------------------------------
 cat/3074 is trying to acquire lock:
 ffffff81f49804c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94

 but task is already holding lock:
 ffffff81f1cc10c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&irq_desc_lock_class);
   lock(&irq_desc_lock_class);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 6 locks held by cat/3074:
  #0: ffffff81f01d9420 (sb_writers#7){.+.+}, at: vfs_write+0xd0/0x1a4
  #1: ffffff81bd7d2080 (&of->mutex){+.+.}, at: kernfs_fop_write+0x12c/0x1fc
  #2: ffffff81f4c322f0 (kn->count#337){.+.+}, at: kernfs_fop_write+0x134/0x1fc
  #3: ffffffe411a41d60 (system_transition_mutex){+.+.}, at: pm_suspend+0x108/0x348
  #4: ffffff81f1c5e970 (&dev->mutex){....}, at: __device_suspend+0x168/0x41c
  #5: ffffff81f1cc10c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94

 stack backtrace:
 CPU: 5 PID: 3074 Comm: cat Tainted: G        W         5.4.11 #3
 Hardware name: Google Cheza (rev3+) (DT)
 Call trace:
  dump_backtrace+0x0/0x174
  show_stack+0x20/0x2c
  dump_stack+0xc8/0x124
  __lock_acquire+0x460/0x2388
  lock_acquire+0x1cc/0x210
  _raw_spin_lock_irqsave+0x64/0x80
  __irq_get_desc_lock+0x64/0x94
  irq_set_irq_wake+0x40/0x144
  qpnpint_irq_set_wake+0x28/0x34
  set_irq_wake_real+0x40/0x5c
  irq_set_irq_wake+0x70/0x144
  pm8941_pwrkey_suspend+0x34/0x44
  platform_pm_suspend+0x34/0x60
  dpm_run_callback+0x64/0xcc
  __device_suspend+0x310/0x41c
  dpm_suspend+0xf8/0x298
  dpm_suspend_start+0x84/0xb4
  suspend_devices_and_enter+0xbc/0x620
  pm_suspend+0x210/0x348
  state_store+0xb0/0x108
  kobj_attr_store+0x14/0x24
  sysfs_kf_write+0x4c/0x64
  kernfs_fop_write+0x15c/0x1fc
  __vfs_write+0x54/0x18c
  vfs_write+0xe4/0x1a4
  ksys_write+0x7c/0xe4
  __arm64_sys_write+0x20/0x2c
  el0_svc_common+0xa8/0x160
  el0_svc_handler+0x7c/0x98
  el0_svc+0x8/0xc

Set a lockdep class when we map the irq so that irq_set_wake() doesn't
warn about a lockdep bug that doesn't exist.

Fixes: 12a9eea ("spmi: pmic-arb: convert to v2 irq interfaces to support hierarchical IRQ chips")
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Brian Masney <masneyb@onstation.org>
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Maulik Shah <mkshah@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20200121183748.68662-1-swboyd@chromium.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
lyakh pushed a commit that referenced this pull request Mar 13, 2020
After bond_release(), netdev_update_lockdep_key() should be called.
But both ioctl path and attribute path don't call
netdev_update_lockdep_key().
This patch adds missing netdev_update_lockdep_key().

Test commands:
    ip link add bond0 type bond
    ip link add bond1 type bond
    ifenslave bond0 bond1
    ifenslave -d bond0 bond1
    ifenslave bond1 bond0

Splat looks like:
[   29.501182][ T1046] WARNING: possible circular locking dependency detected
[   29.501945][ T1039] hardirqs last disabled at (1962): [<ffffffffac6c807f>] handle_mm_fault+0x13f/0x700
[   29.503442][ T1046] 5.5.0+ thesofproject#322 Not tainted
[   29.503447][ T1046] ------------------------------------------------------
[   29.504277][ T1039] softirqs last  enabled at (1180): [<ffffffffade00678>] __do_softirq+0x678/0x981
[   29.505443][ T1046] ifenslave/1046 is trying to acquire lock:
[   29.505886][ T1039] softirqs last disabled at (1169): [<ffffffffac19c18a>] irq_exit+0x17a/0x1a0
[   29.509997][ T1046] ffff88805d5da280 (&dev->addr_list_lock_key#3){+...}, at: dev_mc_sync_multiple+0x95/0x120
[   29.511243][ T1046]
[   29.511243][ T1046] but task is already holding lock:
[   29.512192][ T1046] ffff8880460f2280 (&dev->addr_list_lock_key#4){+...}, at: bond_enslave+0x4482/0x47b0 [bonding]
[   29.514124][ T1046]
[   29.514124][ T1046] which lock already depends on the new lock.
[   29.514124][ T1046]
[   29.517297][ T1046]
[   29.517297][ T1046] the existing dependency chain (in reverse order) is:
[   29.518231][ T1046]
[   29.518231][ T1046] -> #1 (&dev->addr_list_lock_key#4){+...}:
[   29.519076][ T1046]        _raw_spin_lock+0x30/0x70
[   29.519588][ T1046]        dev_mc_sync_multiple+0x95/0x120
[   29.520208][ T1046]        bond_enslave+0x448d/0x47b0 [bonding]
[   29.520862][ T1046]        bond_option_slaves_set+0x1a3/0x370 [bonding]
[   29.521640][ T1046]        __bond_opt_set+0x1ff/0xbb0 [bonding]
[   29.522438][ T1046]        __bond_opt_set_notify+0x2b/0xf0 [bonding]
[   29.523251][ T1046]        bond_opt_tryset_rtnl+0x92/0xf0 [bonding]
[   29.524082][ T1046]        bonding_sysfs_store_option+0x8a/0xf0 [bonding]
[   29.524959][ T1046]        kernfs_fop_write+0x276/0x410
[   29.525620][ T1046]        vfs_write+0x197/0x4a0
[   29.526218][ T1046]        ksys_write+0x141/0x1d0
[   29.526818][ T1046]        do_syscall_64+0x99/0x4f0
[   29.527430][ T1046]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   29.528265][ T1046]
[   29.528265][ T1046] -> #0 (&dev->addr_list_lock_key#3){+...}:
[   29.529272][ T1046]        __lock_acquire+0x2d8d/0x3de0
[   29.529935][ T1046]        lock_acquire+0x164/0x3b0
[   29.530638][ T1046]        _raw_spin_lock+0x30/0x70
[   29.531187][ T1046]        dev_mc_sync_multiple+0x95/0x120
[   29.531790][ T1046]        bond_enslave+0x448d/0x47b0 [bonding]
[   29.532451][ T1046]        bond_option_slaves_set+0x1a3/0x370 [bonding]
[   29.533163][ T1046]        __bond_opt_set+0x1ff/0xbb0 [bonding]
[   29.533789][ T1046]        __bond_opt_set_notify+0x2b/0xf0 [bonding]
[   29.534595][ T1046]        bond_opt_tryset_rtnl+0x92/0xf0 [bonding]
[   29.535500][ T1046]        bonding_sysfs_store_option+0x8a/0xf0 [bonding]
[   29.536379][ T1046]        kernfs_fop_write+0x276/0x410
[   29.537057][ T1046]        vfs_write+0x197/0x4a0
[   29.537640][ T1046]        ksys_write+0x141/0x1d0
[   29.538251][ T1046]        do_syscall_64+0x99/0x4f0
[   29.538870][ T1046]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   29.539659][ T1046]
[   29.539659][ T1046] other info that might help us debug this:
[   29.539659][ T1046]
[   29.540953][ T1046]  Possible unsafe locking scenario:
[   29.540953][ T1046]
[   29.541883][ T1046]        CPU0                    CPU1
[   29.542540][ T1046]        ----                    ----
[   29.543209][ T1046]   lock(&dev->addr_list_lock_key#4);
[   29.543880][ T1046]                                lock(&dev->addr_list_lock_key#3);
[   29.544873][ T1046]                                lock(&dev->addr_list_lock_key#4);
[   29.545863][ T1046]   lock(&dev->addr_list_lock_key#3);
[   29.546525][ T1046]
[   29.546525][ T1046]  *** DEADLOCK ***
[   29.546525][ T1046]
[   29.547542][ T1046] 5 locks held by ifenslave/1046:
[   29.548196][ T1046]  #0: ffff88806044c478 (sb_writers#5){.+.+}, at: vfs_write+0x3bb/0x4a0
[   29.549248][ T1046]  #1: ffff88805af00890 (&of->mutex){+.+.}, at: kernfs_fop_write+0x1cf/0x410
[   29.550343][ T1046]  #2: ffff88805b8b54b0 (kn->count#157){.+.+}, at: kernfs_fop_write+0x1f2/0x410
[   29.551575][ T1046]  #3: ffffffffaecf4cf0 (rtnl_mutex){+.+.}, at: bond_opt_tryset_rtnl+0x5f/0xf0 [bonding]
[   29.552819][ T1046]  #4: ffff8880460f2280 (&dev->addr_list_lock_key#4){+...}, at: bond_enslave+0x4482/0x47b0 [bonding]
[   29.554175][ T1046]
[   29.554175][ T1046] stack backtrace:
[   29.554907][ T1046] CPU: 0 PID: 1046 Comm: ifenslave Not tainted 5.5.0+ thesofproject#322
[   29.555854][ T1046] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   29.557064][ T1046] Call Trace:
[   29.557504][ T1046]  dump_stack+0x96/0xdb
[   29.558054][ T1046]  check_noncircular+0x371/0x450
[   29.558723][ T1046]  ? print_circular_bug.isra.35+0x310/0x310
[   29.559486][ T1046]  ? hlock_class+0x130/0x130
[   29.560100][ T1046]  ? __lock_acquire+0x2d8d/0x3de0
[   29.560761][ T1046]  __lock_acquire+0x2d8d/0x3de0
[   29.561366][ T1046]  ? register_lock_class+0x14d0/0x14d0
[   29.562045][ T1046]  ? find_held_lock+0x39/0x1d0
[   29.562641][ T1046]  lock_acquire+0x164/0x3b0
[   29.563199][ T1046]  ? dev_mc_sync_multiple+0x95/0x120
[   29.563872][ T1046]  _raw_spin_lock+0x30/0x70
[   29.564464][ T1046]  ? dev_mc_sync_multiple+0x95/0x120
[   29.565146][ T1046]  dev_mc_sync_multiple+0x95/0x120
[   29.565793][ T1046]  bond_enslave+0x448d/0x47b0 [bonding]
[   29.566487][ T1046]  ? bond_update_slave_arr+0x940/0x940 [bonding]
[   29.567279][ T1046]  ? bstr_printf+0xc20/0xc20
[   29.567857][ T1046]  ? stack_trace_consume_entry+0x160/0x160
[   29.568614][ T1046]  ? deactivate_slab.isra.77+0x2c5/0x800
[   29.569320][ T1046]  ? check_chain_key+0x236/0x5d0
[   29.569939][ T1046]  ? sscanf+0x93/0xc0
[   29.570442][ T1046]  ? vsscanf+0x1e20/0x1e20
[   29.571003][ T1046]  bond_option_slaves_set+0x1a3/0x370 [bonding]
[ ... ]

Fixes: ab92d68 ("net: core: add generic lockdep keys")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
lyakh pushed a commit that referenced this pull request Mar 13, 2020
The only time we actually leave the path spinning is if we're truncating
a small amount and don't actually free an extent, which is not a common
occurrence.  We have to set the path blocking in order to add the
delayed ref anyway, so the first extent we find we set the path to
blocking and stay blocking for the duration of the operation.  With the
upcoming file extent map stuff there will be another case that we have
to have the path blocking, so just swap to blocking always.

Note: this patch also fixes a warning after 28553fa ("Btrfs: fix
race between shrinking truncate and fiemap") got merged that inserts
extent locks around truncation so the path must not leave spinning locks
after btrfs_search_slot.

  [70.794783] BUG: sleeping function called from invalid context at mm/slab.h:565
  [70.794834] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1141, name: rsync
  [70.794863] 5 locks held by rsync/1141:
  [70.794876]  #0: ffff888417b9c408 (sb_writers#17){.+.+}, at: mnt_want_write+0x20/0x50
  [70.795030]  #1: ffff888428de28e8 (&type->i_mutex_dir_key#13/1){+.+.}, at: lock_rename+0xf1/0x100
  [70.795051]  #2: ffff888417b9c608 (sb_internal#2){.+.+}, at: start_transaction+0x394/0x560
  [70.795124]  #3: ffff888403081768 (btrfs-fs-01){++++}, at: btrfs_try_tree_write_lock+0x2f/0x160
  [70.795203]  #4: ffff888403086568 (btrfs-fs-00){++++}, at: btrfs_try_tree_write_lock+0x2f/0x160
  [70.795222] CPU: 5 PID: 1141 Comm: rsync Not tainted 5.6.0-rc2-backup+ #2
  [70.795362] Call Trace:
  [70.795374]  dump_stack+0x71/0xa0
  [70.795445]  ___might_sleep.part.96.cold.106+0xa6/0xb6
  [70.795459]  kmem_cache_alloc+0x1d3/0x290
  [70.795471]  alloc_extent_state+0x22/0x1c0
  [70.795544]  __clear_extent_bit+0x3ba/0x580
  [70.795557]  ? _raw_spin_unlock_irq+0x24/0x30
  [70.795569]  btrfs_truncate_inode_items+0x339/0xe50
  [70.795647]  btrfs_evict_inode+0x269/0x540
  [70.795659]  ? dput.part.38+0x29/0x460
  [70.795671]  evict+0xcd/0x190
  [70.795682]  __dentry_kill+0xd6/0x180
  [70.795754]  dput.part.38+0x2ad/0x460
  [70.795765]  do_renameat2+0x3cb/0x540
  [70.795777]  __x64_sys_rename+0x1c/0x20

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Fixes: 28553fa ("Btrfs: fix race between shrinking truncate and fiemap")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note ]
Signed-off-by: David Sterba <dsterba@suse.com>
lyakh pushed a commit that referenced this pull request Mar 13, 2020
Damien Le Moal reports a lockdep splat with the acpi_power_meter,
observed with Linux v5.5 and later.

======================================================
WARNING: possible circular locking dependency detected
5.6.0-rc2+ thesofproject#629 Not tainted
------------------------------------------------------
python/1397 is trying to acquire lock:
ffff888619080070 (&resource->lock){+.+.}, at: show_power+0x3c/0xa0 [acpi_power_meter]

               but task is already holding lock:
ffff88881643f188 (kn->count#119){++++}, at: kernfs_seq_start+0x6a/0x160

               which lock already depends on the new lock.

               the existing dependency chain (in reverse order) is:

               -> #1 (kn->count#119){++++}:
       __kernfs_remove+0x626/0x7e0
       kernfs_remove_by_name_ns+0x41/0x80
       remove_attrs+0xcb/0x3c0 [acpi_power_meter]
       acpi_power_meter_notify+0x1f7/0x310 [acpi_power_meter]
       acpi_ev_notify_dispatch+0x198/0x1f3
       acpi_os_execute_deferred+0x4d/0x70
       process_one_work+0x7c8/0x1340
       worker_thread+0x94/0xc70
       kthread+0x2ed/0x3f0
       ret_from_fork+0x24/0x30

               -> #0 (&resource->lock){+.+.}:
       __lock_acquire+0x20be/0x49b0
       lock_acquire+0x127/0x340
       __mutex_lock+0x15b/0x1350
       show_power+0x3c/0xa0 [acpi_power_meter]
       dev_attr_show+0x3f/0x80
       sysfs_kf_seq_show+0x216/0x410
       seq_read+0x407/0xf90
       vfs_read+0x152/0x2c0
       ksys_read+0xf3/0x1d0
       do_syscall_64+0x95/0x1010
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

               other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(kn->count#119);
                               lock(&resource->lock);
                               lock(kn->count#119);
  lock(&resource->lock);

                *** DEADLOCK ***
4 locks held by python/1397:
 #0: ffff8890242d64e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x9b/0xb0
 #1: ffff889040be74e0 (&p->lock){+.+.}, at: seq_read+0x6b/0xf90
 #2: ffff8890448eb880 (&of->mutex){+.+.}, at: kernfs_seq_start+0x47/0x160
 #3: ffff88881643f188 (kn->count#119){++++}, at: kernfs_seq_start+0x6a/0x160

               stack backtrace:
CPU: 10 PID: 1397 Comm: python Not tainted 5.6.0-rc2+ thesofproject#629
Hardware name: Supermicro Super Server/X11DPL-i, BIOS 3.1 05/21/2019
Call Trace:
 dump_stack+0x97/0xe0
 check_noncircular+0x32e/0x3e0
 ? print_circular_bug.isra.0+0x1e0/0x1e0
 ? unwind_next_frame+0xb9a/0x1890
 ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
 ? graph_lock+0x79/0x170
 ? __lockdep_reset_lock+0x3c0/0x3c0
 ? mark_lock+0xbc/0x1150
 __lock_acquire+0x20be/0x49b0
 ? mark_held_locks+0xe0/0xe0
 ? stack_trace_save+0x91/0xc0
 lock_acquire+0x127/0x340
 ? show_power+0x3c/0xa0 [acpi_power_meter]
 ? device_remove_bin_file+0x10/0x10
 ? device_remove_bin_file+0x10/0x10
 __mutex_lock+0x15b/0x1350
 ? show_power+0x3c/0xa0 [acpi_power_meter]
 ? show_power+0x3c/0xa0 [acpi_power_meter]
 ? mutex_lock_io_nested+0x11f0/0x11f0
 ? lock_downgrade+0x6a0/0x6a0
 ? kernfs_seq_start+0x47/0x160
 ? lock_acquire+0x127/0x340
 ? kernfs_seq_start+0x6a/0x160
 ? device_remove_bin_file+0x10/0x10
 ? show_power+0x3c/0xa0 [acpi_power_meter]
 show_power+0x3c/0xa0 [acpi_power_meter]
 dev_attr_show+0x3f/0x80
 ? memset+0x20/0x40
 sysfs_kf_seq_show+0x216/0x410
 seq_read+0x407/0xf90
 ? security_file_permission+0x16f/0x2c0
 vfs_read+0x152/0x2c0

Problem is that reading an attribute takes the kernfs lock in the kernfs
code, then resource->lock in the driver. During an ACPI notification, the
opposite happens: The resource lock is taken first, followed by the kernfs
lock when sysfs attributes are removed and re-created. Presumably this is
now seen due to some locking related changes in kernfs after v5.4, but it
was likely always a problem.

Fix the problem by not blindly acquiring the lock in the notification
function. It is only needed to protect the various update functions.
However, those update functions are called anyway when sysfs attributes
are read. This means that we can just stop calling those functions from
the notifier, and the resource lock in the notifier function is no longer
needed.

That leaves two situations:

First, METER_NOTIFY_CONFIG removes and re-allocates capability strings.
While it did so under the resource lock, _displaying_ those strings was not
protected, creating a race condition. To solve this problem, selectively
protect both removal/creation and reporting of capability attributes with
the resource lock.

Second, removing and re-creating the attribute files is no longer protected
by the resource lock. That doesn't matter since access to each individual
attribute is protected by the kernfs lock. Userspace may get messed up if
attributes disappear and reappear under its nose, but that is not different
than today, and there is nothing we can do about it without major driver
restructuring.

Last but not least, when removing the driver, remove attribute functions
first, then release capability strings. This avoids yet another race
condition.

Reported-by: Damien Le Moal <Damien.LeMoal@wdc.com>
Cc: Damien Le Moal <Damien.LeMoal@wdc.com>
Cc: stable@vger.kernel.org # v5.5+
Tested-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
lyakh pushed a commit that referenced this pull request Mar 19, 2020
Luo bin says:

====================
hinic: BugFixes

the bug fixed in patch #2 has been present since the first commit.
the bugs fixed in patch #1 and patch #3 have been present since the
following commits:
patch #1: 352f58b ("net-next/hinic: Set Rxq irq to specific cpu for NUMA")
patch #3: 421e952 ("hinic: add rss support")
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
lyakh pushed a commit that referenced this pull request Mar 19, 2020
rmnet_get_port() internally calls rcu_dereference_rtnl(),
which checks RTNL.
But rmnet_get_port() could be called by packet path.
The packet path is not protected by RTNL.
So, the suspicious RCU usage problem occurs.

Test commands:
    modprobe rmnet
    ip netns add nst
    ip link add veth0 type veth peer name veth1
    ip link set veth1 netns nst
    ip link add rmnet0 link veth0 type rmnet mux_id 1
    ip netns exec nst ip link add rmnet1 link veth1 type rmnet mux_id 1
    ip netns exec nst ip link set veth1 up
    ip netns exec nst ip link set rmnet1 up
    ip netns exec nst ip a a 192.168.100.2/24 dev rmnet1
    ip link set veth0 up
    ip link set rmnet0 up
    ip a a 192.168.100.1/24 dev rmnet0
    ping 192.168.100.2

Splat looks like:
[  146.630958][ T1174] WARNING: suspicious RCU usage
[  146.631735][ T1174] 5.6.0-rc1+ thesofproject#447 Not tainted
[  146.632387][ T1174] -----------------------------
[  146.633151][ T1174] drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c:386 suspicious rcu_dereference_check() !
[  146.634742][ T1174]
[  146.634742][ T1174] other info that might help us debug this:
[  146.634742][ T1174]
[  146.645992][ T1174]
[  146.645992][ T1174] rcu_scheduler_active = 2, debug_locks = 1
[  146.646937][ T1174] 5 locks held by ping/1174:
[  146.647609][ T1174]  #0: ffff8880c31dea70 (sk_lock-AF_INET){+.+.}, at: raw_sendmsg+0xab8/0x2980
[  146.662463][ T1174]  #1: ffffffff93925660 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x243/0x2150
[  146.671696][ T1174]  #2: ffffffff93925660 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x213/0x2940
[  146.673064][ T1174]  #3: ffff8880c19ecd58 (&dev->qdisc_running_key#7){+...}, at: ip_finish_output2+0x714/0x2150
[  146.690358][ T1174]  #4: ffff8880c5796898 (&dev->qdisc_xmit_lock_key#3){+.-.}, at: sch_direct_xmit+0x1e2/0x1020
[  146.699875][ T1174]
[  146.699875][ T1174] stack backtrace:
[  146.701091][ T1174] CPU: 0 PID: 1174 Comm: ping Not tainted 5.6.0-rc1+ thesofproject#447
[  146.705215][ T1174] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  146.706565][ T1174] Call Trace:
[  146.707102][ T1174]  dump_stack+0x96/0xdb
[  146.708007][ T1174]  rmnet_get_port.part.9+0x76/0x80 [rmnet]
[  146.709233][ T1174]  rmnet_egress_handler+0x107/0x420 [rmnet]
[  146.710492][ T1174]  ? sch_direct_xmit+0x1e2/0x1020
[  146.716193][ T1174]  rmnet_vnd_start_xmit+0x3d/0xa0 [rmnet]
[  146.717012][ T1174]  dev_hard_start_xmit+0x160/0x740
[  146.717854][ T1174]  sch_direct_xmit+0x265/0x1020
[  146.718577][ T1174]  ? register_lock_class+0x14d0/0x14d0
[  146.719429][ T1174]  ? dev_watchdog+0xac0/0xac0
[  146.723738][ T1174]  ? __dev_queue_xmit+0x15fd/0x2940
[  146.724469][ T1174]  ? lock_acquire+0x164/0x3b0
[  146.725172][ T1174]  __dev_queue_xmit+0x20c7/0x2940
[ ... ]

Fixes: ceed73a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
lyakh pushed a commit that referenced this pull request Mar 19, 2020
journal_head::b_transaction and journal_head::b_next_transaction could
be accessed concurrently as noticed by KCSAN,

 LTP: starting fsync04
 /dev/zero: Can't open blockdev
 EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem
 EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null)
 ==================================================================
 BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2]

 write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70:
  __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2]
  __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569
  jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2]
  (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034
  kjournald2+0x13b/0x450 [jbd2]
  kthread+0x1cd/0x1f0
  ret_from_fork+0x27/0x50

 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68:
  jbd2_write_access_granted+0x1b2/0x250 [jbd2]
  jbd2_write_access_granted at fs/jbd2/transaction.c:1155
  jbd2_journal_get_write_access+0x2c/0x60 [jbd2]
  __ext4_journal_get_write_access+0x50/0x90 [ext4]
  ext4_mb_mark_diskspace_used+0x158/0x620 [ext4]
  ext4_mb_new_blocks+0x54f/0xca0 [ext4]
  ext4_ind_map_blocks+0xc79/0x1b40 [ext4]
  ext4_map_blocks+0x3b4/0x950 [ext4]
  _ext4_get_block+0xfc/0x270 [ext4]
  ext4_get_block+0x3b/0x50 [ext4]
  __block_write_begin_int+0x22e/0xae0
  __block_write_begin+0x39/0x50
  ext4_write_begin+0x388/0xb50 [ext4]
  generic_perform_write+0x15d/0x290
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 5 locks held by fsync04/25724:
  #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260
  #1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4]
  #2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
  #3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4]
  #4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2]
 irq event stamp: 1407125
 hardirqs last  enabled at (1407125): [<ffffffff980da9b7>] __find_get_block+0x107/0x790
 hardirqs last disabled at (1407124): [<ffffffff980da8f9>] __find_get_block+0x49/0x790
 softirqs last  enabled at (1405528): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c
 softirqs last disabled at (1405521): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ #7
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

The plain reads are outside of jh->b_state_lock critical section which result
in data races. Fix them by adding pairs of READ|WRITE_ONCE().

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/20200222043111.2227-1-cai@lca.pw
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
lyakh pushed a commit that referenced this pull request Apr 15, 2020
…event

An eventfd monitors multiple memory thresholds of the cgroup, closes them,
the kernel deletes all events related to this eventfd.  Before all events
are deleted, another eventfd monitors the memory threshold of this cgroup,
leading to a crash:

  BUG: kernel NULL pointer dereference, address: 0000000000000004
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 800000033058e067 P4D 800000033058e067 PUD 3355ce067 PMD 0
  Oops: 0002 [#1] SMP PTI
  CPU: 2 PID: 14012 Comm: kworker/2:6 Kdump: loaded Not tainted 5.6.0-rc4 #3
  Hardware name: LENOVO 20AWS01K00/20AWS01K00, BIOS GLET70WW (2.24 ) 05/21/2014
  Workqueue: events memcg_event_remove
  RIP: 0010:__mem_cgroup_usage_unregister_event+0xb3/0x190
  RSP: 0018:ffffb47e01c4fe18 EFLAGS: 00010202
  RAX: 0000000000000001 RBX: ffff8bb223a8a000 RCX: 0000000000000001
  RDX: 0000000000000001 RSI: ffff8bb22fb83540 RDI: 0000000000000001
  RBP: ffffb47e01c4fe48 R08: 0000000000000000 R09: 0000000000000010
  R10: 000000000000000c R11: 071c71c71c71c71c R12: ffff8bb226aba880
  R13: ffff8bb223a8a480 R14: 0000000000000000 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff8bb242680000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000004 CR3: 000000032c29c003 CR4: 00000000001606e0
  Call Trace:
    memcg_event_remove+0x32/0x90
    process_one_work+0x172/0x380
    worker_thread+0x49/0x3f0
    kthread+0xf8/0x130
    ret_from_fork+0x35/0x40
  CR2: 0000000000000004

We can reproduce this problem in the following ways:

1. We create a new cgroup subdirectory and a new eventfd, and then we
   monitor multiple memory thresholds of the cgroup through this eventfd.

2.  closing this eventfd, and __mem_cgroup_usage_unregister_event ()
   will be called multiple times to delete all events related to this
   eventfd.

The first time __mem_cgroup_usage_unregister_event() is called, the
kernel will clear all items related to this eventfd in thresholds->
primary.

Since there is currently only one eventfd, thresholds-> primary becomes
empty, so the kernel will set thresholds-> primary and hresholds-> spare
to NULL.  If at this time, the user creates a new eventfd and monitor
the memory threshold of this cgroup, kernel will re-initialize
thresholds-> primary.

Then when __mem_cgroup_usage_unregister_event () is called for the
second time, because thresholds-> primary is not empty, the system will
access thresholds-> spare, but thresholds-> spare is NULL, which will
trigger a crash.

In general, the longer it takes to delete all events related to this
eventfd, the easier it is to trigger this problem.

The solution is to check whether the thresholds associated with the
eventfd has been cleared when deleting the event.  If so, we do nothing.

[akpm@linux-foundation.org: fix comment, per Kirill]
Fixes: 907860e ("cgroups: make cftype.unregister_event() void-returning")
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/077a6f67-aefa-4591-efec-f2f3af2b0b02@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lyakh pushed a commit that referenced this pull request Jun 9, 2020
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 <nhorman@tuxdriver.com>
CC: Vlad Yasevich <vyasevich@gmail.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: jere.leppanen@nokia.com
CC: marcelo.leitner@gmail.com
CC: netdev@vger.kernel.org
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
lyakh pushed a commit that referenced this pull request Jan 28, 2021
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 <gnault@redhat.com>
Fixes: 571912c ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Link: https://lore.kernel.org/r/20201228152136.24215-1-ap420073@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
lyakh pushed a commit that referenced this pull request Jan 28, 2021
Ido Schimmel says:

====================
nexthop: Various fixes

This series contains various fixes for the nexthop code. The bugs were
uncovered during the development of resilient nexthop groups.

Patches #1-#2 fix the error path of nexthop_create_group(). I was not
able to trigger these bugs with current code, but it is possible with
the upcoming resilient nexthop groups code which adds a user
controllable memory allocation further in the function.

Patch #3 fixes wrong validation of netlink attributes.

Patch #4 fixes wrong invocation of mausezahn in a selftest.
====================

Link: https://lore.kernel.org/r/20210107144824.1135691-1-idosch@idosch.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
lyakh pushed a commit that referenced this pull request 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 <jinpu.wang@cloud.ionos.com>
Reviewed-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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