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Add support for PF LightBrick (LEDS)#4

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rhempel merged 3 commits intoev3dev-jessiefrom
wedo-led
Nov 26, 2014
Merged

Add support for PF LightBrick (LEDS)#4
rhempel merged 3 commits intoev3dev-jessiefrom
wedo-led

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@rhempel rhempel commented Nov 26, 2014

All set to go! I may break this up into a separate wedo_lightbrick.c file eventually

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dlech commented Nov 26, 2014

Looks good to me.

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rhempel commented Nov 26, 2014

You want I should pull this one?

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dlech commented Nov 26, 2014

Go for it.

rhempel added a commit that referenced this pull request Nov 26, 2014
Add support for PF LightBrick (LEDS)
@rhempel rhempel merged commit 69f0f85 into ev3dev-jessie Nov 26, 2014
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rhempel commented Nov 26, 2014

I'm going to go ahead and delete the wedo-led and wedo-support branches while I'm in here

@rhempel rhempel deleted the wedo-led branch November 26, 2014 03:56
cunctator pushed a commit to cunctator/ev3dev-kernel that referenced this pull request Jan 4, 2015
commit 3c5445c upstream.

We allocate the cpufreq table after calling rcu_read_lock(),
which disables preemption. This causes scheduling while atomic
warnings. Use GFP_ATOMIC instead of GFP_KERNEL and update for
kcalloc while we're here.

BUG: sleeping function called from invalid context at mm/slub.c:1246
in_atomic(): 0, irqs_disabled(): 0, pid: 80, name: modprobe
5 locks held by modprobe/80:
 #0:  (&dev->mutex){......}, at: [<c050d484>] __driver_attach+0x48/0x98
 ev3dev#1:  (&dev->mutex){......}, at: [<c050d494>] __driver_attach+0x58/0x98
 ev3dev#2:  (subsys mutex#5){+.+.+.}, at: [<c050c114>] subsys_interface_register+0x38/0xc8
 ev3dev#3:  (cpufreq_rwsem){.+.+.+}, at: [<c05a9c8c>] __cpufreq_add_dev.isra.22+0x84/0x92c
 ev3dev#4:  (rcu_read_lock){......}, at: [<c05ab24c>] dev_pm_opp_init_cpufreq_table+0x18/0x10c
Preemption disabled at:[<  (null)>]   (null)

CPU: 2 PID: 80 Comm: modprobe Not tainted 3.16.0-rc3-next-20140701-00035-g286857f216aa-dirty #217
[<c0214da8>] (unwind_backtrace) from [<c02123f8>] (show_stack+0x10/0x14)
[<c02123f8>] (show_stack) from [<c070141c>] (dump_stack+0x70/0xbc)
[<c070141c>] (dump_stack) from [<c02f4cb0>] (__kmalloc+0x124/0x250)
[<c02f4cb0>] (__kmalloc) from [<c05ab270>] (dev_pm_opp_init_cpufreq_table+0x3c/0x10c)
[<c05ab270>] (dev_pm_opp_init_cpufreq_table) from [<bf000508>] (cpufreq_init+0x48/0x378 [cpufreq_generic])
[<bf000508>] (cpufreq_init [cpufreq_generic]) from [<c05a9e08>] (__cpufreq_add_dev.isra.22+0x200/0x92c)
[<c05a9e08>] (__cpufreq_add_dev.isra.22) from [<c050c160>] (subsys_interface_register+0x84/0xc8)
[<c050c160>] (subsys_interface_register) from [<c05a9494>] (cpufreq_register_driver+0x108/0x2d8)
[<c05a9494>] (cpufreq_register_driver) from [<bf000888>] (generic_cpufreq_probe+0x50/0x74 [cpufreq_generic])
[<bf000888>] (generic_cpufreq_probe [cpufreq_generic]) from [<c050e994>] (platform_drv_probe+0x18/0x48)
[<c050e994>] (platform_drv_probe) from [<c050d1f4>] (driver_probe_device+0x128/0x370)
[<c050d1f4>] (driver_probe_device) from [<c050d4d0>] (__driver_attach+0x94/0x98)
[<c050d4d0>] (__driver_attach) from [<c050b778>] (bus_for_each_dev+0x54/0x88)
[<c050b778>] (bus_for_each_dev) from [<c050c894>] (bus_add_driver+0xe8/0x204)
[<c050c894>] (bus_add_driver) from [<c050dd48>] (driver_register+0x78/0xf4)
[<c050dd48>] (driver_register) from [<c0208870>] (do_one_initcall+0xac/0x1d8)
[<c0208870>] (do_one_initcall) from [<c028b6b4>] (load_module+0x190c/0x21e8)
[<c028b6b4>] (load_module) from [<c028c034>] (SyS_init_module+0xa4/0x110)
[<c028c034>] (SyS_init_module) from [<c020f0c0>] (ret_fast_syscall+0x0/0x48)

Fixes: a0dd7b7 (PM / OPP: Move cpufreq specific OPP functions out of generic OPP library)
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Jan 6, 2015
…ap()

commit aef4885 upstream.

Error report likely result in IO so it is bad idea to do it from
atomic context.

This patch should fix following issue:

BUG: sleeping function called from invalid context at include/linux/buffer_head.h:349
in_atomic(): 1, irqs_disabled(): 0, pid: 137, name: kworker/u128:1
5 locks held by kworker/u128:1/137:
 #0:  ("writeback"){......}, at: [<ffffffff81085618>] process_one_work+0x228/0x4d0
 #1:  ((&(&wb->dwork)->work)){......}, at: [<ffffffff81085618>] process_one_work+0x228/0x4d0
 #2:  (jbd2_handle){......}, at: [<ffffffff81242622>] start_this_handle+0x712/0x7b0
 #3:  (&ei->i_data_sem){......}, at: [<ffffffff811fa387>] ext4_map_blocks+0x297/0x430
 #4:  (&(&bgl->locks[i].lock)->rlock){......}, at: [<ffffffff811f3180>] ext4_read_block_bitmap_nowait+0x5d0/0x630
CPU: 3 PID: 137 Comm: kworker/u128:1 Not tainted 3.17.0-rc2-00184-g82752e4 #165
Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.99.99.x028.061320111235 06/13/2011
Workqueue: writeback bdi_writeback_workfn (flush-1:0)
 0000000000000411 ffff880813777288 ffffffff815c7fdc ffff880813777288
 ffff880813a8bba0 ffff8808137772a8 ffffffff8108fb30 ffff880803e01e38
 ffff880803e01e38 ffff8808137772c8 ffffffff811a8d53 ffff88080ecc6000
Call Trace:
 [<ffffffff815c7fdc>] dump_stack+0x51/0x6d
 [<ffffffff8108fb30>] __might_sleep+0xf0/0x100
 [<ffffffff811a8d53>] __sync_dirty_buffer+0x43/0xe0
 [<ffffffff811a8e03>] sync_dirty_buffer+0x13/0x20
 [<ffffffff8120f581>] ext4_commit_super+0x1d1/0x230
 [<ffffffff8120fa03>] save_error_info+0x23/0x30
 [<ffffffff8120fd06>] __ext4_error+0xb6/0xd0
 [<ffffffff8120f260>] ? ext4_group_desc_csum+0x140/0x190
 [<ffffffff811f2d8c>] ext4_read_block_bitmap_nowait+0x1dc/0x630
 [<ffffffff8122e23a>] ext4_mb_init_cache+0x21a/0x8f0
 [<ffffffff8113ae95>] ? lru_cache_add+0x55/0x60
 [<ffffffff8112e16c>] ? add_to_page_cache_lru+0x6c/0x80
 [<ffffffff8122eaa0>] ext4_mb_init_group+0x190/0x280
 [<ffffffff8122ec51>] ext4_mb_good_group+0xc1/0x190
 [<ffffffff8123309a>] ext4_mb_regular_allocator+0x17a/0x410
 [<ffffffff8122c821>] ? ext4_mb_use_preallocated+0x31/0x380
 [<ffffffff81233535>] ? ext4_mb_new_blocks+0x205/0x8e0
 [<ffffffff8116ed5c>] ? kmem_cache_alloc+0xfc/0x180
 [<ffffffff812335b0>] ext4_mb_new_blocks+0x280/0x8e0
 [<ffffffff8116f2c4>] ? __kmalloc+0x144/0x1c0
 [<ffffffff81221797>] ? ext4_find_extent+0x97/0x320
 [<ffffffff812257f4>] ext4_ext_map_blocks+0xbc4/0x1050
 [<ffffffff811fa387>] ? ext4_map_blocks+0x297/0x430
 [<ffffffff811fa3ab>] ext4_map_blocks+0x2bb/0x430
 [<ffffffff81200e43>] ? ext4_init_io_end+0x23/0x50
 [<ffffffff811feb44>] ext4_writepages+0x564/0xaf0
 [<ffffffff815cde3b>] ? _raw_spin_unlock+0x2b/0x40
 [<ffffffff810ac7bd>] ? lock_release_non_nested+0x2fd/0x3c0
 [<ffffffff811a009e>] ? writeback_sb_inodes+0x10e/0x490
 [<ffffffff811a009e>] ? writeback_sb_inodes+0x10e/0x490
 [<ffffffff811377e3>] do_writepages+0x23/0x40
 [<ffffffff8119c8ce>] __writeback_single_inode+0x9e/0x280
 [<ffffffff811a026b>] writeback_sb_inodes+0x2db/0x490
 [<ffffffff811a0664>] wb_writeback+0x174/0x2d0
 [<ffffffff810ac359>] ? lock_release_holdtime+0x29/0x190
 [<ffffffff811a0863>] wb_do_writeback+0xa3/0x200
 [<ffffffff811a0a40>] bdi_writeback_workfn+0x80/0x230
 [<ffffffff81085618>] ? process_one_work+0x228/0x4d0
 [<ffffffff810856cd>] process_one_work+0x2dd/0x4d0
 [<ffffffff81085618>] ? process_one_work+0x228/0x4d0
 [<ffffffff81085c1d>] worker_thread+0x35d/0x460
 [<ffffffff810858c0>] ? process_one_work+0x4d0/0x4d0
 [<ffffffff810858c0>] ? process_one_work+0x4d0/0x4d0
 [<ffffffff8108a885>] kthread+0xf5/0x100
 [<ffffffff810990e5>] ? local_clock+0x25/0x30
 [<ffffffff8108a790>] ? __init_kthread_worker+0x70/0x70
 [<ffffffff815ce2ac>] ret_from_fork+0x7c/0xb0
 [<ffffffff8108a790>] ? __init_kthread_work

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
dlech pushed a commit that referenced this pull request Feb 22, 2015
commit ce75145 upstream.

It is possible for ata_sff_flush_pio_task() to set ap->hsm_task_state to
HSM_ST_IDLE in between the time __ata_sff_port_intr() checks for HSM_ST_IDLE
and before it calls ata_sff_hsm_move() causing ata_sff_hsm_move() to BUG().

This problem is hard to reproduce making this patch hard to verify, but this
fix will prevent the race.

I have not been able to reproduce the problem, but here is a crash dump from
a 2.6.32 kernel.

On examining the ata port's state, its hsm_task_state field has a value of HSM_ST_IDLE:

crash> struct ata_port.hsm_task_state ffff881c1121c000
  hsm_task_state = 0

Normally, this should not be possible as ata_sff_hsm_move() was called from ata_sff_host_intr(),
which checks hsm_task_state and won't call ata_sff_hsm_move() if it has a HSM_ST_IDLE value.

PID: 11053  TASK: ffff8816e846cae0  CPU: 0   COMMAND: "sshd"
 #0 [ffff88008ba03960] machine_kexec at ffffffff81038f3b
 #1 [ffff88008ba039c0] crash_kexec at ffffffff810c5d92
 #2 [ffff88008ba03a90] oops_end at ffffffff8152b510
 #3 [ffff88008ba03ac0] die at ffffffff81010e0b
 #4 [ffff88008ba03af0] do_trap at ffffffff8152ad74
 #5 [ffff88008ba03b50] do_invalid_op at ffffffff8100cf95
 #6 [ffff88008ba03bf0] invalid_op at ffffffff8100bf9b
    [exception RIP: ata_sff_hsm_move+317]
    RIP: ffffffff813a77ad  RSP: ffff88008ba03ca0  RFLAGS: 00010097
    RAX: 0000000000000000  RBX: ffff881c1121dc60  RCX: 0000000000000000
    RDX: ffff881c1121dd10  RSI: ffff881c1121dc60  RDI: ffff881c1121c000
    RBP: ffff88008ba03d00   R8: 0000000000000000   R9: 000000000000002e
    R10: 000000000001003f  R11: 000000000000009b  R12: ffff881c1121c000
    R13: 0000000000000000  R14: 0000000000000050  R15: ffff881c1121dd78
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #7 [ffff88008ba03d08] ata_sff_host_intr at ffffffff813a7fbd
 #8 [ffff88008ba03d38] ata_sff_interrupt at ffffffff813a821e
 #9 [ffff88008ba03d78] handle_IRQ_event at ffffffff810e6ec0
--- <IRQ stack> ---
    [exception RIP: pipe_poll+48]
    RIP: ffffffff81192780  RSP: ffff880f26d459b8  RFLAGS: 00000246
    RAX: 0000000000000000  RBX: ffff880f26d459c8  RCX: 0000000000000000
    RDX: 0000000000000001  RSI: 0000000000000000  RDI: ffff881a0539fa80
    RBP: ffffffff8100bb8e   R8: ffff8803b23324a0   R9: 0000000000000000
    R10: ffff880f26d45dd0  R11: 0000000000000008  R12: ffffffff8109b646
    R13: ffff880f26d45948  R14: 0000000000000246  R15: 0000000000000246
    ORIG_RAX: ffffffffffffff10  CS: 0010  SS: 0018
    RIP: 00007f26017435c3  RSP: 00007fffe020c420  RFLAGS: 00000206
    RAX: 0000000000000017  RBX: ffffffff8100b072  RCX: 00007fffe020c45c
    RDX: 00007f2604a3f120  RSI: 00007f2604a3f140  RDI: 000000000000000d
    RBP: 0000000000000000   R8: 00007fffe020e570   R9: 0101010101010101
    R10: 0000000000000000  R11: 0000000000000246  R12: 00007fffe020e5f0
    R13: 00007fffe020e5f4  R14: 00007f26045f373c  R15: 00007fffe020e5e0
    ORIG_RAX: 0000000000000017  CS: 0033  SS: 002b

Somewhere between the ata_sff_hsm_move() check and the ata_sff_host_intr() check, the value changed.
On examining the other cpus to see what else was running, another cpu was running the error handler
routines:

PID: 326    TASK: ffff881c11014aa0  CPU: 1   COMMAND: "scsi_eh_1"
 #0 [ffff88008ba27e90] crash_nmi_callback at ffffffff8102fee6
 #1 [ffff88008ba27ea0] notifier_call_chain at ffffffff8152d515
 #2 [ffff88008ba27ee0] atomic_notifier_call_chain at ffffffff8152d57a
 #3 [ffff88008ba27ef0] notify_die at ffffffff810a154e
 #4 [ffff88008ba27f20] do_nmi at ffffffff8152b1db
 #5 [ffff88008ba27f50] nmi at ffffffff8152aaa0
    [exception RIP: _spin_lock_irqsave+47]
    RIP: ffffffff8152a1ff  RSP: ffff881c11a73aa0  RFLAGS: 00000006
    RAX: 0000000000000001  RBX: ffff881c1121deb8  RCX: 0000000000000000
    RDX: 0000000000000246  RSI: 0000000000000020  RDI: ffff881c122612d8
    RBP: ffff881c11a73aa0   R8: ffff881c17083800   R9: 0000000000000000
    R10: 0000000000000000  R11: 0000000000000000  R12: ffff881c1121c000
    R13: 000000000000001f  R14: ffff881c1121dd50  R15: ffff881c1121dc60
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
--- <NMI exception stack> ---
 #6 [ffff881c11a73aa0] _spin_lock_irqsave at ffffffff8152a1ff
 #7 [ffff881c11a73aa8] ata_exec_internal_sg at ffffffff81396fb5
 #8 [ffff881c11a73b58] ata_exec_internal at ffffffff81397109
 #9 [ffff881c11a73bd8] atapi_eh_request_sense at ffffffff813a34eb

Before it tried to acquire a spinlock, ata_exec_internal_sg() called ata_sff_flush_pio_task().
This function will set ap->hsm_task_state to HSM_ST_IDLE, and has no locking around setting this
value. ata_sff_flush_pio_task() can then race with the interrupt handler and potentially set
HSM_ST_IDLE at a fatal moment, which will trigger a kernel BUG.

v2: Fixup comment in ata_sff_flush_pio_task()

tj: Further updated comment.  Use ap->lock instead of shost lock and
    use the [un]lock_irq variant instead of the irqsave/restore one.

Signed-off-by: David Milburn <dmilburn@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
dlech pushed a commit that referenced this pull request Apr 13, 2015
commit 4c672e4 upstream.

It has been reported that generating an MLD listener report on
devices with large MTUs (e.g. 9000) and a high number of IPv6
addresses can trigger a skb_over_panic():

skbuff: skb_over_panic: text:ffffffff80612a5d len:3776 put:20
head:ffff88046d751000 data:ffff88046d751010 tail:0xed0 end:0xec0
dev:port1
 ------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:100!
invalid opcode: 0000 [#1] SMP
Modules linked in: ixgbe(O)
CPU: 3 PID: 0 Comm: swapper/3 Tainted: G O 3.14.23+ #4
[...]
Call Trace:
 <IRQ>
 [<ffffffff80578226>] ? skb_put+0x3a/0x3b
 [<ffffffff80612a5d>] ? add_grhead+0x45/0x8e
 [<ffffffff80612e3a>] ? add_grec+0x394/0x3d4
 [<ffffffff80613222>] ? mld_ifc_timer_expire+0x195/0x20d
 [<ffffffff8061308d>] ? mld_dad_timer_expire+0x45/0x45
 [<ffffffff80255b5d>] ? call_timer_fn.isra.29+0x12/0x68
 [<ffffffff80255d16>] ? run_timer_softirq+0x163/0x182
 [<ffffffff80250e6f>] ? __do_softirq+0xe0/0x21d
 [<ffffffff8025112b>] ? irq_exit+0x4e/0xd3
 [<ffffffff802214bb>] ? smp_apic_timer_interrupt+0x3b/0x46
 [<ffffffff8063f10a>] ? apic_timer_interrupt+0x6a/0x70

mld_newpack() skb allocations are usually requested with dev->mtu
in size, since commit 72e09ad ("ipv6: avoid high order allocations")
we have changed the limit in order to be less likely to fail.

However, in MLD/IGMP code, we have some rather ugly AVAILABLE(skb)
macros, which determine if we may end up doing an skb_put() for
adding another record. To avoid possible fragmentation, we check
the skb's tailroom as skb->dev->mtu - skb->len, which is a wrong
assumption as the actual max allocation size can be much smaller.

The IGMP case doesn't have this issue as commit 57e1ab6
("igmp: refine skb allocations") stores the allocation size in
the cb[].

Set a reserved_tailroom to make it fit into the MTU and use
skb_availroom() helper instead. This also allows to get rid of
igmp_skb_size().

Reported-by: Wei Liu <lw1a2.jing@gmail.com>
Fixes: 72e09ad ("ipv6: avoid high order allocations")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: David L Stevens <david.stevens@oracle.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
dlech pushed a commit that referenced this pull request May 14, 2015
commit d744194 upstream.

Sebastian reported a crash caused by a jump label mismatch after resume.
This happens because we do not save the kernel text section during suspend
and therefore also do not restore it during resume, but use the kernel image
that restores the old system.

This means that after a suspend/resume cycle we lost all modifications done
to the kernel text section.
The reason for this is the pfn_is_nosave() function, which incorrectly
returns that read-only pages don't need to be saved. This is incorrect since
we mark the kernel text section read-only.
We still need to make sure to not save and restore pages contained within
NSS and DCSS segment.
To fix this add an extra case for the kernel text section and only save
those pages if they are not contained within an NSS segment.

Fixes the following crash (and the above bugs as well):

Jump label code mismatch at netif_receive_skb_internal+0x28/0xd0
Found:    c0 04 00 00 00 00
Expected: c0 f4 00 00 00 11
New:      c0 04 00 00 00 00
Kernel panic - not syncing: Corrupted kernel text
CPU: 0 PID: 9 Comm: migration/0 Not tainted 3.19.0-01975-gb1b096e70f23 #4
Call Trace:
  [<0000000000113972>] show_stack+0x72/0xf0
  [<000000000081f15e>] dump_stack+0x6e/0x90
  [<000000000081c4e8>] panic+0x108/0x2b0
  [<000000000081be64>] jump_label_bug.isra.2+0x104/0x108
  [<0000000000112176>] __jump_label_transform+0x9e/0xd0
  [<00000000001121e6>] __sm_arch_jump_label_transform+0x3e/0x50
  [<00000000001d1136>] multi_cpu_stop+0x12e/0x170
  [<00000000001d1472>] cpu_stopper_thread+0xb2/0x168
  [<000000000015d2ac>] smpboot_thread_fn+0x134/0x1b0
  [<0000000000158baa>] kthread+0x10a/0x110
  [<0000000000824a86>] kernel_thread_starter+0x6/0xc

Reported-and-tested-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
dlech pushed a commit that referenced this pull request Nov 9, 2015
commit ecf5fc6 upstream.

Nikolay has reported a hang when a memcg reclaim got stuck with the
following backtrace:

PID: 18308  TASK: ffff883d7c9b0a30  CPU: 1   COMMAND: "rsync"
  #0 __schedule at ffffffff815ab152
  #1 schedule at ffffffff815ab76e
  #2 schedule_timeout at ffffffff815ae5e5
  #3 io_schedule_timeout at ffffffff815aad6a
  #4 bit_wait_io at ffffffff815abfc6
  #5 __wait_on_bit at ffffffff815abda5
  #6 wait_on_page_bit at ffffffff8111fd4f
  #7 shrink_page_list at ffffffff81135445
  #8 shrink_inactive_list at ffffffff81135845
  #9 shrink_lruvec at ffffffff81135ead
 #10 shrink_zone at ffffffff811360c3
 #11 shrink_zones at ffffffff81136eff
 #12 do_try_to_free_pages at ffffffff8113712f
 #13 try_to_free_mem_cgroup_pages at ffffffff811372be
 #14 try_charge at ffffffff81189423
 #15 mem_cgroup_try_charge at ffffffff8118c6f5
 #16 __add_to_page_cache_locked at ffffffff8112137d
 #17 add_to_page_cache_lru at ffffffff81121618
 #18 pagecache_get_page at ffffffff8112170b
 #19 grow_dev_page at ffffffff811c8297
 #20 __getblk_slow at ffffffff811c91d6
 #21 __getblk_gfp at ffffffff811c92c1
 #22 ext4_ext_grow_indepth at ffffffff8124565c
 #23 ext4_ext_create_new_leaf at ffffffff81246ca8
 #24 ext4_ext_insert_extent at ffffffff81246f09
 #25 ext4_ext_map_blocks at ffffffff8124a848
 #26 ext4_map_blocks at ffffffff8121a5b7
 #27 mpage_map_one_extent at ffffffff8121b1fa
 #28 mpage_map_and_submit_extent at ffffffff8121f07b
 #29 ext4_writepages at ffffffff8121f6d5
 #30 do_writepages at ffffffff8112c490
 #31 __filemap_fdatawrite_range at ffffffff81120199
 #32 filemap_flush at ffffffff8112041c
 #33 ext4_alloc_da_blocks at ffffffff81219da1
 #34 ext4_rename at ffffffff81229b91
 #35 ext4_rename2 at ffffffff81229e32
 #36 vfs_rename at ffffffff811a08a5
 #37 SYSC_renameat2 at ffffffff811a3ffc
 #38 sys_renameat2 at ffffffff811a408e
 #39 sys_rename at ffffffff8119e51e
 #40 system_call_fastpath at ffffffff815afa89

Dave Chinner has properly pointed out that this is a deadlock in the
reclaim code because ext4 doesn't submit pages which are marked by
PG_writeback right away.

The heuristic was introduced by commit e62e384 ("memcg: prevent OOM
with too many dirty pages") and it was applied only when may_enter_fs
was specified.  The code has been changed by c3b94f4 ("memcg:
further prevent OOM with too many dirty pages") which has removed the
__GFP_FS restriction with a reasoning that we do not get into the fs
code.  But this is not sufficient apparently because the fs doesn't
necessarily submit pages marked PG_writeback for IO right away.

ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily
submit the bio.  Instead it tries to map more pages into the bio and
mpage_map_one_extent might trigger memcg charge which might end up
waiting on a page which is marked PG_writeback but hasn't been submitted
yet so we would end up waiting for something that never finishes.

Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2)
before we go to wait on the writeback.  The page fault path, which is
the only path that triggers memcg oom killer since 3.12, shouldn't
require GFP_NOFS and so we shouldn't reintroduce the premature OOM
killer issue which was originally addressed by the heuristic.

As per David Chinner the xfs is doing similar thing since 2.6.15 already
so ext4 is not the only affected filesystem.  Moreover he notes:

: For example: IO completion might require unwritten extent conversion
: which executes filesystem transactions and GFP_NOFS allocations. The
: writeback flag on the pages can not be cleared until unwritten
: extent conversion completes. Hence memory reclaim cannot wait on
: page writeback to complete in GFP_NOFS context because it is not
: safe to do so, memcg reclaim or otherwise.

[tytso@mit.edu: corrected the control flow]
Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages")
Reported-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ luis: backported to 3.16: used Hugh's backport for 4.1 ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
dlech pushed a commit that referenced this pull request Dec 15, 2015
commit e81107d upstream.

My colleague ran into a program stall on a x86_64 server, where
n_tty_read() was waiting for data even if there was data in the buffer
in the pty.  kernel stack for the stuck process looks like below.
 #0 [ffff88303d107b58] __schedule at ffffffff815c4b20
 #1 [ffff88303d107bd0] schedule at ffffffff815c513e
 #2 [ffff88303d107bf0] schedule_timeout at ffffffff815c7818
 #3 [ffff88303d107ca0] wait_woken at ffffffff81096bd2
 #4 [ffff88303d107ce0] n_tty_read at ffffffff8136fa23
 #5 [ffff88303d107dd0] tty_read at ffffffff81368013
 #6 [ffff88303d107e20] __vfs_read at ffffffff811a3704
 #7 [ffff88303d107ec0] vfs_read at ffffffff811a3a57
 #8 [ffff88303d107f00] sys_read at ffffffff811a4306
 #9 [ffff88303d107f50] entry_SYSCALL_64_fastpath at ffffffff815c86d7

There seems to be two problems causing this issue.

First, in drivers/tty/n_tty.c, __receive_buf() stores the data and
updates ldata->commit_head using smp_store_release() and then checks
the wait queue using waitqueue_active().  However, since there is no
memory barrier, __receive_buf() could return without calling
wake_up_interactive_poll(), and at the same time, n_tty_read() could
start to wait in wait_woken() as in the following chart.

        __receive_buf()                         n_tty_read()
------------------------------------------------------------------------
if (waitqueue_active(&tty->read_wait))
/* Memory operations issued after the
   RELEASE may be completed before the
   RELEASE operation has completed */
                                        add_wait_queue(&tty->read_wait, &wait);
                                        ...
                                        if (!input_available_p(tty, 0)) {
smp_store_release(&ldata->commit_head,
                  ldata->read_head);
                                        ...
                                        timeout = wait_woken(&wait,
                                          TASK_INTERRUPTIBLE, timeout);
------------------------------------------------------------------------

The second problem is that n_tty_read() also lacks a memory barrier
call and could also cause __receive_buf() to return without calling
wake_up_interactive_poll(), and n_tty_read() to wait in wait_woken()
as in the chart below.

        __receive_buf()                         n_tty_read()
------------------------------------------------------------------------
                                        spin_lock_irqsave(&q->lock, flags);
                                        /* from add_wait_queue() */
                                        ...
                                        if (!input_available_p(tty, 0)) {
                                        /* Memory operations issued after the
                                           RELEASE may be completed before the
                                           RELEASE operation has completed */
smp_store_release(&ldata->commit_head,
                  ldata->read_head);
if (waitqueue_active(&tty->read_wait))
                                        __add_wait_queue(q, wait);
                                        spin_unlock_irqrestore(&q->lock,flags);
                                        /* from add_wait_queue() */
                                        ...
                                        timeout = wait_woken(&wait,
                                          TASK_INTERRUPTIBLE, timeout);
------------------------------------------------------------------------

There are also other places in drivers/tty/n_tty.c which have similar
calls to waitqueue_active(), so instead of adding many memory barrier
calls, this patch simply removes the call to waitqueue_active(),
leaving just wake_up*() behind.

This fixes both problems because, even though the memory access before
or after the spinlocks in both wake_up*() and add_wait_queue() can
sneak into the critical section, it cannot go past it and the critical
section assures that they will be serialized (please see "INTER-CPU
ACQUIRING BARRIER EFFECTS" in Documentation/memory-barriers.txt for a
better explanation).  Moreover, the resulting code is much simpler.

Latency measurement using a ping-pong test over a pty doesn't show any
visible performance drop.

Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ luis: backported to 3.16:
  - always use wake_up_interruptible() instead of wake_up_interruptible_poll()
  - adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
dlech pushed a commit that referenced this pull request Apr 11, 2016
commit 3d5fe03 upstream.

We can end up allocating a new compression stream with GFP_KERNEL from
within the IO path, which may result is nested (recursive) IO
operations.  That can introduce problems if the IO path in question is a
reclaimer, holding some locks that will deadlock nested IOs.

Allocate streams and working memory using GFP_NOIO flag, forbidding
recursive IO and FS operations.

An example:

  inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
  git/20158 [HC0[0]:SC0[0]:HE1:SE1] takes:
   (jbd2_handle){+.+.?.}, at:  start_this_handle+0x4ca/0x555
  {IN-RECLAIM_FS-W} state was registered at:
     __lock_acquire+0x8da/0x117b
     lock_acquire+0x10c/0x1a7
     start_this_handle+0x52d/0x555
     jbd2__journal_start+0xb4/0x237
     __ext4_journal_start_sb+0x108/0x17e
     ext4_dirty_inode+0x32/0x61
     __mark_inode_dirty+0x16b/0x60c
     iput+0x11e/0x274
     __dentry_kill+0x148/0x1b8
     shrink_dentry_list+0x274/0x44a
     prune_dcache_sb+0x4a/0x55
     super_cache_scan+0xfc/0x176
     shrink_slab.part.14.constprop.25+0x2a2/0x4d3
     shrink_zone+0x74/0x140
     kswapd+0x6b7/0x930
     kthread+0x107/0x10f
     ret_from_fork+0x3f/0x70
  irq event stamp: 138297
  hardirqs last  enabled at (138297):  debug_check_no_locks_freed+0x113/0x12f
  hardirqs last disabled at (138296):  debug_check_no_locks_freed+0x33/0x12f
  softirqs last  enabled at (137818):  __do_softirq+0x2d3/0x3e9
  softirqs last disabled at (137813):  irq_exit+0x41/0x95

               other info that might help us debug this:
   Possible unsafe locking scenario:
         CPU0
         ----
    lock(jbd2_handle);
    <Interrupt>
      lock(jbd2_handle);

                *** DEADLOCK ***
  5 locks held by git/20158:
   #0:  (sb_writers#7){.+.+.+}, at: [<ffffffff81155411>] mnt_want_write+0x24/0x4b
   #1:  (&type->i_mutex_dir_key#2/1){+.+.+.}, at: [<ffffffff81145087>] lock_rename+0xd9/0xe3
   #2:  (&sb->s_type->i_mutex_key#11){+.+.+.}, at: [<ffffffff8114f8e2>] lock_two_nondirectories+0x3f/0x6b
   #3:  (&sb->s_type->i_mutex_key#11/4){+.+.+.}, at: [<ffffffff8114f909>] lock_two_nondirectories+0x66/0x6b
   #4:  (jbd2_handle){+.+.?.}, at: [<ffffffff811e31db>] start_this_handle+0x4ca/0x555

               stack backtrace:
  CPU: 2 PID: 20158 Comm: git Not tainted 4.1.0-rc7-next-20150615-dbg-00016-g8bdf555-dirty #211
  Call Trace:
    dump_stack+0x4c/0x6e
    mark_lock+0x384/0x56d
    mark_held_locks+0x5f/0x76
    lockdep_trace_alloc+0xb2/0xb5
    kmem_cache_alloc_trace+0x32/0x1e2
    zcomp_strm_alloc+0x25/0x73 [zram]
    zcomp_strm_multi_find+0xe7/0x173 [zram]
    zcomp_strm_find+0xc/0xe [zram]
    zram_bvec_rw+0x2ca/0x7e0 [zram]
    zram_make_request+0x1fa/0x301 [zram]
    generic_make_request+0x9c/0xdb
    submit_bio+0xf7/0x120
    ext4_io_submit+0x2e/0x43
    ext4_bio_write_page+0x1b7/0x300
    mpage_submit_page+0x60/0x77
    mpage_map_and_submit_buffers+0x10f/0x21d
    ext4_writepages+0xc8c/0xe1b
    do_writepages+0x23/0x2c
    __filemap_fdatawrite_range+0x84/0x8b
    filemap_flush+0x1c/0x1e
    ext4_alloc_da_blocks+0xb8/0x117
    ext4_rename+0x132/0x6dc
    ? mark_held_locks+0x5f/0x76
    ext4_rename2+0x29/0x2b
    vfs_rename+0x540/0x636
    SyS_renameat2+0x359/0x44d
    SyS_rename+0x1e/0x20
    entry_SYSCALL_64_fastpath+0x12/0x6f

[minchan@kernel.org: add stable mark]
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Kyeongdon Kim <kyeongdon.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
dlech pushed a commit that referenced this pull request Apr 11, 2016
commit ac75fe5 upstream.

That prevents this bug:
[ 2382.269496] BUG: unable to handle kernel NULL pointer dereference at 0000000000000540
[ 2382.270013] IP: [<ffffffffa01fe616>] snd_card_free+0x36/0x70 [snd]
[ 2382.270013] PGD 0
[ 2382.270013] Oops: 0002 [#1] SMP
[ 2382.270013] Modules linked in: saa7134_alsa(-) tda1004x saa7134_dvb videobuf2_dvb dvb_core tda827x tda8290 tuner saa7134 tveeprom videobuf2_dma_sg videobuf2_memops videobuf2_v4l2 videobuf2_core v4l2_common videodev media auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc tun bridge stp llc ebtables ip6table_filter ip6_tables nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack it87 hwmon_vid snd_hda_codec_idt snd_hda_codec_generic iTCO_wdt iTCO_vendor_support snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq pcspkr i2c_i801 snd_seq_device snd_pcm snd_timer lpc_ich snd mfd_core soundcore binfmt_misc i915 video i2c_algo_bit drm_kms_helper drm r8169 ata_generic serio_raw pata_acpi mii i2c_core [last unloaded: videobuf2_memops]
[ 2382.270013] CPU: 0 PID: 4899 Comm: rmmod Not tainted 4.5.0-rc1+ #4
[ 2382.270013] Hardware name: PCCHIPS P17G/P17G, BIOS 080012  05/14/2008
[ 2382.270013] task: ffff880039c38000 ti: ffff88003c764000 task.ti: ffff88003c764000
[ 2382.270013] RIP: 0010:[<ffffffffa01fe616>]  [<ffffffffa01fe616>] snd_card_free+0x36/0x70 [snd]
[ 2382.270013] RSP: 0018:ffff88003c767ea0  EFLAGS: 00010286
[ 2382.270013] RAX: ffff88003c767eb8 RBX: 0000000000000000 RCX: 0000000000006260
[ 2382.270013] RDX: ffffffffa020a060 RSI: ffffffffa0206de1 RDI: ffff88003c767eb0
[ 2382.270013] RBP: ffff88003c767ed8 R08: 0000000000019960 R09: ffffffff811a5412
[ 2382.270013] R10: ffffea0000d7c200 R11: 0000000000000000 R12: ffff88003c767ea8
[ 2382.270013] R13: 00007ffe760617f7 R14: 0000000000000000 R15: 0000557625d7f1e0
[ 2382.270013] FS:  00007f80bb1c0700(0000) GS:ffff88003f400000(0000) knlGS:0000000000000000
[ 2382.270013] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 2382.270013] CR2: 0000000000000540 CR3: 000000003c00f000 CR4: 00000000000006f0
[ 2382.270013] Stack:
[ 2382.270013]  000000003c767ed8 ffffffff00000000 ffff880000000000 ffff88003c767eb8
[ 2382.270013]  ffff88003c767eb8 ffffffffa049a890 00007ffe76060060 ffff88003c767ef0
[ 2382.270013]  ffffffffa049889d ffffffffa049a500 ffff88003c767f48 ffffffff8111079c
[ 2382.270013] Call Trace:
[ 2382.270013]  [<ffffffffa049889d>] saa7134_alsa_exit+0x1d/0x780 [saa7134_alsa]
[ 2382.270013]  [<ffffffff8111079c>] SyS_delete_module+0x19c/0x1f0
[ 2382.270013]  [<ffffffff8170fc2e>] entry_SYSCALL_64_fastpath+0x12/0x71
[ 2382.270013] Code: 20 a0 48 c7 c6 e1 6d 20 a0 48 89 e5 41 54 53 4c 8d 65 d0 48 89 fb 48 83 ec 28 c7 45 d0 00 00 00 00 49 8d 7c 24 08 e8 7a 55 ed e0 <4c> 89 a3 40 05 00 00 48 89 df e8 eb fd ff ff 85 c0 75 1a 48 8d
[ 2382.270013] RIP  [<ffffffffa01fe616>] snd_card_free+0x36/0x70 [snd]
[ 2382.270013]  RSP <ffff88003c767ea0>
[ 2382.270013] CR2: 0000000000000540

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
dlech pushed a commit that referenced this pull request Apr 11, 2016
commit d144dfe upstream.

If we use USB ID pin as wakeup source, and there is a USB block
device on this USB OTG (ID) cable, the system will be deadlock
after system resume.

The root cause for this problem is: the workqueue ci_otg may try
to remove hcd before the driver resume has finished, and hcd will
disconnect the device on it, then, it will call device_release_driver,
and holds the device lock "dev->mutex", but it is never unlocked since
it waits workqueue writeback to run to flush the block information, but
the workqueue writeback is freezable, it is not thawed before driver
resume has finished.

When the driver (device: sd 0:0:0:0:) resume goes to dpm_complete, it
tries to get its device lock "dev->mutex", but it can't get it forever,
then the deadlock occurs. Below call stacks show the situation.

So, in order to fix this problem, we need to change workqueue ci_otg
as freezable, then the work item in this workqueue will be run after
driver's resume, this workqueue will not be blocked forever like above
case since the workqueue writeback has been thawed too.

Tested at: i.mx6qdl-sabresd and i.mx6sx-sdb.

[  555.178869] kworker/u2:13   D c07de74c     0   826      2 0x00000000
[  555.185310] Workqueue: ci_otg ci_otg_work
[  555.189353] Backtrace:
[  555.191849] [<c07de4fc>] (__schedule) from [<c07dec6c>] (schedule+0x48/0xa0)
[  555.198912]  r10:ee471ba0 r9:00000000 r8:00000000 r7:00000002 r6:ee470000 r5:ee471ba4
[  555.206867]  r4:ee470000
[  555.209453] [<c07dec24>] (schedule) from [<c07e2fc4>] (schedule_timeout+0x15c/0x1e0)
[  555.217212]  r4:7fffffff r3:edc2b000
[  555.220862] [<c07e2e68>] (schedule_timeout) from [<c07df6c8>] (wait_for_common+0x94/0x144)
[  555.229140]  r8:00000000 r7:00000002 r6:ee470000 r5:ee471ba4 r4:7fffffff
[  555.235980] [<c07df634>] (wait_for_common) from [<c07df790>] (wait_for_completion+0x18/0x1c)
[  555.244430]  r10:00000001 r9:c0b5563c r8:c0042e48 r7:ef086000 r6:eea4372c r5:ef131b00
[  555.252383]  r4:00000000
[  555.254970] [<c07df778>] (wait_for_completion) from [<c0043cb8>] (flush_work+0x19c/0x234)
[  555.263177] [<c0043b1c>] (flush_work) from [<c0043fac>] (flush_delayed_work+0x48/0x4c)
[  555.271106]  r8:ed5b5000 r7:c0b38a3c r6:eea439cc r5:eea4372c r4:eea4372c
[  555.277958] [<c0043f64>] (flush_delayed_work) from [<c00eae18>] (bdi_unregister+0x84/0xec)
[  555.286236]  r4:eea43520 r3:20000153
[  555.289885] [<c00ead94>] (bdi_unregister) from [<c02c2154>] (blk_cleanup_queue+0x180/0x29c)
[  555.298250]  r5:eea43808 r4:eea43400
[  555.301909] [<c02c1fd4>] (blk_cleanup_queue) from [<c0417914>] (__scsi_remove_device+0x48/0xb8)
[  555.310623]  r7:00000000 r6:20000153 r5:ededa950 r4:ededa800
[  555.316403] [<c04178cc>] (__scsi_remove_device) from [<c0415e90>] (scsi_forget_host+0x64/0x68)
[  555.325028]  r5:ededa800 r4:ed5b5000
[  555.328689] [<c0415e2c>] (scsi_forget_host) from [<c0409828>] (scsi_remove_host+0x78/0x104)
[  555.337054]  r5:ed5b5068 r4:ed5b5000
[  555.340709] [<c04097b0>] (scsi_remove_host) from [<c04cdfcc>] (usb_stor_disconnect+0x50/0xb4)
[  555.349247]  r6:ed5b56e4 r5:ed5b5818 r4:ed5b5690 r3:00000008
[  555.355025] [<c04cdf7c>] (usb_stor_disconnect) from [<c04b3bc8>] (usb_unbind_interface+0x78/0x25c)
[  555.363997]  r8:c13919b4 r7:edd3c000 r6:edd3c020 r5:ee551c68 r4:ee551c00 r3:c04cdf7c
[  555.371892] [<c04b3b50>] (usb_unbind_interface) from [<c03dc248>] (__device_release_driver+0x8c/0x118)
[  555.381213]  r10:00000001 r9:edd90c00 r8:c13919b4 r7:ee551c68 r6:c0b546e0 r5:c0b5563c
[  555.389167]  r4:edd3c020
[  555.391752] [<c03dc1bc>] (__device_release_driver) from [<c03dc2fc>] (device_release_driver+0x28/0x34)
[  555.401071]  r5:edd3c020 r4:edd3c054
[  555.404721] [<c03dc2d4>] (device_release_driver) from [<c03db304>] (bus_remove_device+0xe0/0x110)
[  555.413607]  r5:edd3c020 r4:ef17f04c
[  555.417253] [<c03db224>] (bus_remove_device) from [<c03d8128>] (device_del+0x114/0x21c)
[  555.425270]  r6:edd3c028 r5:edd3c020 r4:ee551c00 r3:00000000
[  555.431045] [<c03d8014>] (device_del) from [<c04b1560>] (usb_disable_device+0xa4/0x1e8)
[  555.439061]  r8:edd3c000 r7:eded8000 r6:00000000 r5:00000001 r4:ee551c00
[  555.445906] [<c04b14bc>] (usb_disable_device) from [<c04a8e54>] (usb_disconnect+0x74/0x224)
[  555.454271]  r9:edd90c00 r8:ee551000 r7:ee551c68 r6:ee551c9c r5:ee551c00 r4:00000001
[  555.462156] [<c04a8de0>] (usb_disconnect) from [<c04a8fb8>] (usb_disconnect+0x1d8/0x224)
[  555.470259]  r10:00000001 r9:edd90000 r8:ee471e2c r7:ee551468 r6:ee55149c r5:ee551400
[  555.478213]  r4:00000001
[  555.480797] [<c04a8de0>] (usb_disconnect) from [<c04ae5ec>] (usb_remove_hcd+0xa0/0x1ac)
[  555.488813]  r10:00000001 r9:ee471eb0 r8:00000000 r7:ef3d9500 r6:eded810c r5:eded80b0
[  555.496765]  r4:eded8000
[  555.499351] [<c04ae54c>] (usb_remove_hcd) from [<c04d4158>] (host_stop+0x28/0x64)
[  555.506847]  r6:eeb50010 r5:eded8000 r4:eeb51010
[  555.511563] [<c04d4130>] (host_stop) from [<c04d09b8>] (ci_otg_work+0xc4/0x124)
[  555.518885]  r6:00000001 r5:eeb50010 r4:eeb502a0 r3:c04d4130
[  555.524665] [<c04d08f4>] (ci_otg_work) from [<c00454f0>] (process_one_work+0x194/0x420)
[  555.532682]  r6:ef086000 r5:eeb502a0 r4:edc44480
[  555.537393] [<c004535c>] (process_one_work) from [<c00457b0>] (worker_thread+0x34/0x514)
[  555.545496]  r10:edc44480 r9:ef086000 r8:c0b1a100 r7:ef086034 r6:00000088 r5:edc44498
[  555.553450]  r4:ef086000
[  555.556032] [<c004577c>] (worker_thread) from [<c004bab4>] (kthread+0xdc/0xf8)
[  555.563268]  r10:00000000 r9:00000000 r8:00000000 r7:c004577c r6:edc44480 r5:eddc15c0
[  555.571221]  r4:00000000
[  555.573804] [<c004b9d8>] (kthread) from [<c000fef0>] (ret_from_fork+0x14/0x24)
[  555.581040]  r7:00000000 r6:00000000 r5:c004b9d8 r4:eddc15c0

[  553.429383] sh              D c07de74c     0   694    691 0x00000000
[  553.435801] Backtrace:
[  553.438295] [<c07de4fc>] (__schedule) from [<c07dec6c>] (schedule+0x48/0xa0)
[  553.445358]  r10:edd3c054 r9:edd3c078 r8:edddbd50 r7:edcbbc00 r6:c1377c34 r5:60000153
[  553.453313]  r4:eddda000
[  553.455896] [<c07dec24>] (schedule) from [<c07deff8>] (schedule_preempt_disabled+0x10/0x14)
[  553.464261]  r4:edd3c058 r3:0000000a
[  553.467910] [<c07defe8>] (schedule_preempt_disabled) from [<c07e0bbc>] (mutex_lock_nested+0x1a0/0x3e8)
[  553.477254] [<c07e0a1c>] (mutex_lock_nested) from [<c03e927c>] (dpm_complete+0xc0/0x1b0)
[  553.485358]  r10:00561408 r9:edd3c054 r8:c0b4863c r7:edddbd90 r6:c0b485d8 r5:edd3c020
[  553.493313]  r4:edd3c0d0
[  553.495896] [<c03e91bc>] (dpm_complete) from [<c03e9388>] (dpm_resume_end+0x1c/0x20)
[  553.503652]  r9:00000000 r8:c0b1a9d0 r7:c1334ec0 r6:c1334edc r5:00000003 r4:00000010
[  553.511544] [<c03e936c>] (dpm_resume_end) from [<c0079894>] (suspend_devices_and_enter+0x158/0x504)
[  553.520604]  r4:00000000 r3:c1334efc
[  553.524250] [<c007973c>] (suspend_devices_and_enter) from [<c0079e74>] (pm_suspend+0x234/0x2cc)
[  553.532961]  r10:00561408 r9:ed6b7300 r8:00000004 r7:c1334eec r6:00000000 r5:c1334ee8
[  553.540914]  r4:00000003
[  553.543493] [<c0079c40>] (pm_suspend) from [<c0078a6c>] (state_store+0x6c/0xc0)

[  555.703684] 7 locks held by kworker/u2:13/826:
[  555.708140]  #0:  ("%s""ci_otg"){++++.+}, at: [<c0045484>] process_one_work+0x128/0x420
[  555.716277]  #1:  ((&ci->work)){+.+.+.}, at: [<c0045484>] process_one_work+0x128/0x420
[  555.724317]  #2:  (usb_bus_list_lock){+.+.+.}, at: [<c04ae5e4>] usb_remove_hcd+0x98/0x1ac
[  555.732626]  #3:  (&dev->mutex){......}, at: [<c04a8e28>] usb_disconnect+0x48/0x224
[  555.740403]  #4:  (&dev->mutex){......}, at: [<c04a8e28>] usb_disconnect+0x48/0x224
[  555.748179]  #5:  (&dev->mutex){......}, at: [<c03dc2f4>] device_release_driver+0x20/0x34
[  555.756487]  #6:  (&shost->scan_mutex){+.+.+.}, at: [<c04097d0>] scsi_remove_host+0x20/0x104

Cc: Jun Li <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request May 10, 2016
…arm header

arm and arm64 use different config options to specify big endian. This
needs taking into account when including code/headers between the two
architectures.

A case in point is PAN, which uses the __instr_arm() macro to output
instructions. The macro comes from opcodes.h, which lives under arch/arm.
On a big-endian build the mismatched config options mean the instruction
isn't byte swapped correctly, resulting in undefined instruction exceptions
during boot:

| alternatives: patching kernel code
| kdevtmpfs[87]: undefined instruction: pc=ffffffc0004505b4
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| Internal error: Oops - undefined instruction: 0 [ev3dev#1] SMP
| Modules linked in:
| CPU: 0 PID: 87 Comm: kdevtmpfs Not tainted 4.1.16+ ev3dev#5
| Hardware name: Hisilicon PhosphorHi1382 EVB (DT)
| task: ffffffc336591700 ti: ffffffc3365a4000 task.ti: ffffffc3365a4000
| PC is at dump_instr+0x68/0x100
| LR is at do_undefinstr+0x1d4/0x2a4
| pc : [<ffffffc00076231c>] lr : [<ffffffc0000811d4>] pstate: 604001c5
| sp : ffffffc3365a6450

Cc: <stable@vger.kernel.org> ev3dev#4.3.x-
Reported-by: Hanjun Guo <guohanjun@huawei.com>
Tested-by: Xuefeng Wang <wxf.wang@hisilicon.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request May 10, 2016
commit e2c8b87 moved modeset locking inside resume/suspend
functions, but missed a code path only executed on lid close/open
on older hardware. The result was a deadlock when closing and
opening the lid without suspending on such hardware:

 =============================================
 [ INFO: possible recursive locking detected ]
 4.6.0-rc1 #385 Not tainted
 ---------------------------------------------
 kworker/0:3/88 is trying to acquire lock:
  (&dev->mode_config.mutex){+.+.+.}, at: [<ffffffffa063e6a4>] intel_display_resume+0x4a/0x12f [i915]

 but task is already holding lock:
  (&dev->mode_config.mutex){+.+.+.}, at: [<ffffffffa02d0d4f>] drm_modeset_lock_all+0x3e/0xa6 [drm]

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

        CPU0
        ----
   lock(&dev->mode_config.mutex);
   lock(&dev->mode_config.mutex);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 7 locks held by kworker/0:3/88:
  #0:  ("kacpi_notify"){++++.+}, at: [<ffffffff81068dfc>] process_one_work+0x14a/0x50b
  ev3dev#1:  ((&dpc->work)ev3dev#2){+.+.+.}, at: [<ffffffff81068dfc>] process_one_work+0x14a/0x50b
  ev3dev#2:  ((acpi_lid_notifier).rwsem){++++.+}, at: [<ffffffff8106f874>] __blocking_notifier_call_chain+0x34/0x65
  ev3dev#3:  (&dev_priv->modeset_restore_lock){+.+.+.}, at: [<ffffffffa0664cf6>] intel_lid_notify+0x3c/0xd9 [i915]
  ev3dev#4:  (&dev->mode_config.mutex){+.+.+.}, at: [<ffffffffa02d0d4f>] drm_modeset_lock_all+0x3e/0xa6 [drm]
  ev3dev#5:  (crtc_ww_class_acquire){+.+.+.}, at: [<ffffffffa02d0d59>] drm_modeset_lock_all+0x48/0xa6 [drm]
  ev3dev#6:  (crtc_ww_class_mutex){+.+.+.}, at: [<ffffffffa02d0b2a>] modeset_lock+0x13c/0x1cd [drm]

 stack backtrace:
 CPU: 0 PID: 88 Comm: kworker/0:3 Not tainted 4.6.0-rc1 #385
 Hardware name: LENOVO 2776LEG/2776LEG, BIOS 6EET55WW (3.15 ) 12/19/2011
 Workqueue: kacpi_notify acpi_os_execute_deferred
  0000000000000000 ffff88022fd5f990 ffffffff8124af06 ffffffff825b39c0
  ffffffff825b39c0 ffff88022fd5fa60 ffffffff8108f547 ffff88022fd5fa70
  000000008108e817 ffff880230236cc0 0000000000000000 ffffffff825b39c0
 Call Trace:
  [<ffffffff8124af06>] dump_stack+0x67/0x90
  [<ffffffff8108f547>] __lock_acquire+0xdb5/0xf71
  [<ffffffff8108bd2c>] ? look_up_lock_class+0xbe/0x10a
  [<ffffffff8108fae2>] lock_acquire+0x137/0x1cb
  [<ffffffff8108fae2>] ? lock_acquire+0x137/0x1cb
  [<ffffffffa063e6a4>] ? intel_display_resume+0x4a/0x12f [i915]
  [<ffffffff8148202f>] mutex_lock_nested+0x7e/0x3a4
  [<ffffffffa063e6a4>] ? intel_display_resume+0x4a/0x12f [i915]
  [<ffffffffa063e6a4>] ? intel_display_resume+0x4a/0x12f [i915]
  [<ffffffffa02d0b2a>] ? modeset_lock+0x13c/0x1cd [drm]
  [<ffffffffa063e6a4>] intel_display_resume+0x4a/0x12f [i915]
  [<ffffffffa063e6a4>] ? intel_display_resume+0x4a/0x12f [i915]
  [<ffffffffa02d0b2a>] ? modeset_lock+0x13c/0x1cd [drm]
  [<ffffffffa02d0b2a>] ? modeset_lock+0x13c/0x1cd [drm]
  [<ffffffffa02d0bf7>] ? drm_modeset_lock+0x17/0x24 [drm]
  [<ffffffffa02d0c8b>] ? drm_modeset_lock_all_ctx+0x87/0xa1 [drm]
  [<ffffffffa0664d6a>] intel_lid_notify+0xb0/0xd9 [i915]
  [<ffffffff8106f4c6>] notifier_call_chain+0x4a/0x6c
  [<ffffffff8106f88d>] __blocking_notifier_call_chain+0x4d/0x65
  [<ffffffff8106f8b9>] blocking_notifier_call_chain+0x14/0x16
  [<ffffffffa0011215>] acpi_lid_send_state+0x83/0xad [button]
  [<ffffffffa00112a6>] acpi_button_notify+0x41/0x132 [button]
  [<ffffffff812b07df>] acpi_device_notify+0x19/0x1b
  [<ffffffff812c8570>] acpi_ev_notify_dispatch+0x49/0x64
  [<ffffffff812ab9fb>] acpi_os_execute_deferred+0x14/0x20
  [<ffffffff81068f17>] process_one_work+0x265/0x50b
  [<ffffffff810696f5>] worker_thread+0x1fc/0x2dd
  [<ffffffff810694f9>] ? rescuer_thread+0x309/0x309
  [<ffffffff810694f9>] ? rescuer_thread+0x309/0x309
  [<ffffffff8106e2d6>] kthread+0xe0/0xe8
  [<ffffffff8107bc47>] ? local_clock+0x19/0x22
  [<ffffffff81484f42>] ret_from_fork+0x22/0x40
  [<ffffffff8106e1f6>] ? kthread_create_on_node+0x1b5/0x1b5

Fixes: e2c8b87 ("drm/i915: Use atomic helpers for suspend, v2.")
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459328913-13719-1-git-send-email-bjorn@mork.no
(cherry picked from commit 9f54d4b)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request Jun 12, 2016
commit d144dfe upstream.

If we use USB ID pin as wakeup source, and there is a USB block
device on this USB OTG (ID) cable, the system will be deadlock
after system resume.

The root cause for this problem is: the workqueue ci_otg may try
to remove hcd before the driver resume has finished, and hcd will
disconnect the device on it, then, it will call device_release_driver,
and holds the device lock "dev->mutex", but it is never unlocked since
it waits workqueue writeback to run to flush the block information, but
the workqueue writeback is freezable, it is not thawed before driver
resume has finished.

When the driver (device: sd 0:0:0:0:) resume goes to dpm_complete, it
tries to get its device lock "dev->mutex", but it can't get it forever,
then the deadlock occurs. Below call stacks show the situation.

So, in order to fix this problem, we need to change workqueue ci_otg
as freezable, then the work item in this workqueue will be run after
driver's resume, this workqueue will not be blocked forever like above
case since the workqueue writeback has been thawed too.

Tested at: i.mx6qdl-sabresd and i.mx6sx-sdb.

[  555.178869] kworker/u2:13   D c07de74c     0   826      2 0x00000000
[  555.185310] Workqueue: ci_otg ci_otg_work
[  555.189353] Backtrace:
[  555.191849] [<c07de4fc>] (__schedule) from [<c07dec6c>] (schedule+0x48/0xa0)
[  555.198912]  r10:ee471ba0 r9:00000000 r8:00000000 r7:00000002 r6:ee470000 r5:ee471ba4
[  555.206867]  r4:ee470000
[  555.209453] [<c07dec24>] (schedule) from [<c07e2fc4>] (schedule_timeout+0x15c/0x1e0)
[  555.217212]  r4:7fffffff r3:edc2b000
[  555.220862] [<c07e2e68>] (schedule_timeout) from [<c07df6c8>] (wait_for_common+0x94/0x144)
[  555.229140]  r8:00000000 r7:00000002 r6:ee470000 r5:ee471ba4 r4:7fffffff
[  555.235980] [<c07df634>] (wait_for_common) from [<c07df790>] (wait_for_completion+0x18/0x1c)
[  555.244430]  r10:00000001 r9:c0b5563c r8:c0042e48 r7:ef086000 r6:eea4372c r5:ef131b00
[  555.252383]  r4:00000000
[  555.254970] [<c07df778>] (wait_for_completion) from [<c0043cb8>] (flush_work+0x19c/0x234)
[  555.263177] [<c0043b1c>] (flush_work) from [<c0043fac>] (flush_delayed_work+0x48/0x4c)
[  555.271106]  r8:ed5b5000 r7:c0b38a3c r6:eea439cc r5:eea4372c r4:eea4372c
[  555.277958] [<c0043f64>] (flush_delayed_work) from [<c00eae18>] (bdi_unregister+0x84/0xec)
[  555.286236]  r4:eea43520 r3:20000153
[  555.289885] [<c00ead94>] (bdi_unregister) from [<c02c2154>] (blk_cleanup_queue+0x180/0x29c)
[  555.298250]  r5:eea43808 r4:eea43400
[  555.301909] [<c02c1fd4>] (blk_cleanup_queue) from [<c0417914>] (__scsi_remove_device+0x48/0xb8)
[  555.310623]  r7:00000000 r6:20000153 r5:ededa950 r4:ededa800
[  555.316403] [<c04178cc>] (__scsi_remove_device) from [<c0415e90>] (scsi_forget_host+0x64/0x68)
[  555.325028]  r5:ededa800 r4:ed5b5000
[  555.328689] [<c0415e2c>] (scsi_forget_host) from [<c0409828>] (scsi_remove_host+0x78/0x104)
[  555.337054]  r5:ed5b5068 r4:ed5b5000
[  555.340709] [<c04097b0>] (scsi_remove_host) from [<c04cdfcc>] (usb_stor_disconnect+0x50/0xb4)
[  555.349247]  r6:ed5b56e4 r5:ed5b5818 r4:ed5b5690 r3:00000008
[  555.355025] [<c04cdf7c>] (usb_stor_disconnect) from [<c04b3bc8>] (usb_unbind_interface+0x78/0x25c)
[  555.363997]  r8:c13919b4 r7:edd3c000 r6:edd3c020 r5:ee551c68 r4:ee551c00 r3:c04cdf7c
[  555.371892] [<c04b3b50>] (usb_unbind_interface) from [<c03dc248>] (__device_release_driver+0x8c/0x118)
[  555.381213]  r10:00000001 r9:edd90c00 r8:c13919b4 r7:ee551c68 r6:c0b546e0 r5:c0b5563c
[  555.389167]  r4:edd3c020
[  555.391752] [<c03dc1bc>] (__device_release_driver) from [<c03dc2fc>] (device_release_driver+0x28/0x34)
[  555.401071]  r5:edd3c020 r4:edd3c054
[  555.404721] [<c03dc2d4>] (device_release_driver) from [<c03db304>] (bus_remove_device+0xe0/0x110)
[  555.413607]  r5:edd3c020 r4:ef17f04c
[  555.417253] [<c03db224>] (bus_remove_device) from [<c03d8128>] (device_del+0x114/0x21c)
[  555.425270]  r6:edd3c028 r5:edd3c020 r4:ee551c00 r3:00000000
[  555.431045] [<c03d8014>] (device_del) from [<c04b1560>] (usb_disable_device+0xa4/0x1e8)
[  555.439061]  r8:edd3c000 r7:eded8000 r6:00000000 r5:00000001 r4:ee551c00
[  555.445906] [<c04b14bc>] (usb_disable_device) from [<c04a8e54>] (usb_disconnect+0x74/0x224)
[  555.454271]  r9:edd90c00 r8:ee551000 r7:ee551c68 r6:ee551c9c r5:ee551c00 r4:00000001
[  555.462156] [<c04a8de0>] (usb_disconnect) from [<c04a8fb8>] (usb_disconnect+0x1d8/0x224)
[  555.470259]  r10:00000001 r9:edd90000 r8:ee471e2c r7:ee551468 r6:ee55149c r5:ee551400
[  555.478213]  r4:00000001
[  555.480797] [<c04a8de0>] (usb_disconnect) from [<c04ae5ec>] (usb_remove_hcd+0xa0/0x1ac)
[  555.488813]  r10:00000001 r9:ee471eb0 r8:00000000 r7:ef3d9500 r6:eded810c r5:eded80b0
[  555.496765]  r4:eded8000
[  555.499351] [<c04ae54c>] (usb_remove_hcd) from [<c04d4158>] (host_stop+0x28/0x64)
[  555.506847]  r6:eeb50010 r5:eded8000 r4:eeb51010
[  555.511563] [<c04d4130>] (host_stop) from [<c04d09b8>] (ci_otg_work+0xc4/0x124)
[  555.518885]  r6:00000001 r5:eeb50010 r4:eeb502a0 r3:c04d4130
[  555.524665] [<c04d08f4>] (ci_otg_work) from [<c00454f0>] (process_one_work+0x194/0x420)
[  555.532682]  r6:ef086000 r5:eeb502a0 r4:edc44480
[  555.537393] [<c004535c>] (process_one_work) from [<c00457b0>] (worker_thread+0x34/0x514)
[  555.545496]  r10:edc44480 r9:ef086000 r8:c0b1a100 r7:ef086034 r6:00000088 r5:edc44498
[  555.553450]  r4:ef086000
[  555.556032] [<c004577c>] (worker_thread) from [<c004bab4>] (kthread+0xdc/0xf8)
[  555.563268]  r10:00000000 r9:00000000 r8:00000000 r7:c004577c r6:edc44480 r5:eddc15c0
[  555.571221]  r4:00000000
[  555.573804] [<c004b9d8>] (kthread) from [<c000fef0>] (ret_from_fork+0x14/0x24)
[  555.581040]  r7:00000000 r6:00000000 r5:c004b9d8 r4:eddc15c0

[  553.429383] sh              D c07de74c     0   694    691 0x00000000
[  553.435801] Backtrace:
[  553.438295] [<c07de4fc>] (__schedule) from [<c07dec6c>] (schedule+0x48/0xa0)
[  553.445358]  r10:edd3c054 r9:edd3c078 r8:edddbd50 r7:edcbbc00 r6:c1377c34 r5:60000153
[  553.453313]  r4:eddda000
[  553.455896] [<c07dec24>] (schedule) from [<c07deff8>] (schedule_preempt_disabled+0x10/0x14)
[  553.464261]  r4:edd3c058 r3:0000000a
[  553.467910] [<c07defe8>] (schedule_preempt_disabled) from [<c07e0bbc>] (mutex_lock_nested+0x1a0/0x3e8)
[  553.477254] [<c07e0a1c>] (mutex_lock_nested) from [<c03e927c>] (dpm_complete+0xc0/0x1b0)
[  553.485358]  r10:00561408 r9:edd3c054 r8:c0b4863c r7:edddbd90 r6:c0b485d8 r5:edd3c020
[  553.493313]  r4:edd3c0d0
[  553.495896] [<c03e91bc>] (dpm_complete) from [<c03e9388>] (dpm_resume_end+0x1c/0x20)
[  553.503652]  r9:00000000 r8:c0b1a9d0 r7:c1334ec0 r6:c1334edc r5:00000003 r4:00000010
[  553.511544] [<c03e936c>] (dpm_resume_end) from [<c0079894>] (suspend_devices_and_enter+0x158/0x504)
[  553.520604]  r4:00000000 r3:c1334efc
[  553.524250] [<c007973c>] (suspend_devices_and_enter) from [<c0079e74>] (pm_suspend+0x234/0x2cc)
[  553.532961]  r10:00561408 r9:ed6b7300 r8:00000004 r7:c1334eec r6:00000000 r5:c1334ee8
[  553.540914]  r4:00000003
[  553.543493] [<c0079c40>] (pm_suspend) from [<c0078a6c>] (state_store+0x6c/0xc0)

[  555.703684] 7 locks held by kworker/u2:13/826:
[  555.708140]  #0:  ("%s""ci_otg"){++++.+}, at: [<c0045484>] process_one_work+0x128/0x420
[  555.716277]  ev3dev#1:  ((&ci->work)){+.+.+.}, at: [<c0045484>] process_one_work+0x128/0x420
[  555.724317]  ev3dev#2:  (usb_bus_list_lock){+.+.+.}, at: [<c04ae5e4>] usb_remove_hcd+0x98/0x1ac
[  555.732626]  ev3dev#3:  (&dev->mutex){......}, at: [<c04a8e28>] usb_disconnect+0x48/0x224
[  555.740403]  ev3dev#4:  (&dev->mutex){......}, at: [<c04a8e28>] usb_disconnect+0x48/0x224
[  555.748179]  ev3dev#5:  (&dev->mutex){......}, at: [<c03dc2f4>] device_release_driver+0x20/0x34
[  555.756487]  ev3dev#6:  (&shost->scan_mutex){+.+.+.}, at: [<c04097d0>] scsi_remove_host+0x20/0x104

Cc: Jun Li <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request Jun 12, 2016
commit 7d3fdff upstream.

Restore the lost phys status page cleanup.

Fixes the following splat with DMA_API_DEBUG=y:

WARNING: CPU: 0 PID: 21615 at ../lib/dma-debug.c:974 dma_debug_device_change+0x190/0x1f0()
pci 0000:00:02.0: DMA-API: device driver has pending DMA allocations while released from device [count=1]
               One of leaked entries details: [device address=0x0000000023163000] [size=4096 bytes] [mapped with DMA_BIDIRECTIONAL] [mapped as coherent]
Modules linked in: i915(-) i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm sha256_generic hmac drbg ctr ccm sch_fq_codel binfmt_misc joydev mousedev arc4 ath5k iTCO_wdt mac80211 smsc_ircc2 ath snd_intel8x0m snd_intel8x0 snd_ac97_codec ac97_bus psmouse snd_pcm input_leds i2c_i801 pcspkr snd_timer cfg80211 snd soundcore i2c_core ehci_pci firewire_ohci ehci_hcd firewire_core lpc_ich 8139too rfkill crc_itu_t mfd_core mii usbcore rng_core intel_agp intel_gtt usb_common agpgart irda crc_ccitt fujitsu_laptop led_class parport_pc video parport evdev backlight
CPU: 0 PID: 21615 Comm: rmmod Tainted: G     U          4.4.0-rc4-mgm-ovl+ ev3dev#4
Hardware name: FUJITSU SIEMENS LIFEBOOK S6120/FJNB16C, BIOS Version 1.26  05/10/2004
 e31a3de0 e31a3de0 e31a3d9c c128d4bd e31a3dd0 c1045a0c c15e00c4 e31a3dfc
 0000546f c15dfad2 000003ce c12b3740 000003ce c12b3740 00000000 00000001
 f61fb8a0 e31a3de8 c1045a83 00000009 e31a3de0 c15e00c4 e31a3dfc e31a3e4c
Call Trace:
 [<c128d4bd>] dump_stack+0x16/0x19
 [<c1045a0c>] warn_slowpath_common+0x8c/0xd0
 [<c12b3740>] ? dma_debug_device_change+0x190/0x1f0
 [<c12b3740>] ? dma_debug_device_change+0x190/0x1f0
 [<c1045a83>] warn_slowpath_fmt+0x33/0x40
 [<c12b3740>] dma_debug_device_change+0x190/0x1f0
 [<c1065499>] notifier_call_chain+0x59/0x70
 [<c10655af>] __blocking_notifier_call_chain+0x3f/0x80
 [<c106560f>] blocking_notifier_call_chain+0x1f/0x30
 [<c134cfb3>] __device_release_driver+0xc3/0xf0
 [<c134d0d7>] driver_detach+0x97/0xa0
 [<c134c440>] bus_remove_driver+0x40/0x90
 [<c134db18>] driver_unregister+0x28/0x60
 [<c1079e8c>] ? trace_hardirqs_on_caller+0x12c/0x1d0
 [<c12c0618>] pci_unregister_driver+0x18/0x80
 [<f83e96e7>] drm_pci_exit+0x87/0xb0 [drm]
 [<f8b3be2d>] i915_exit+0x1b/0x1ee [i915]
 [<c10b999c>] SyS_delete_module+0x14c/0x210
 [<c1079e8c>] ? trace_hardirqs_on_caller+0x12c/0x1d0
 [<c115a9bd>] ? ____fput+0xd/0x10
 [<c1002014>] do_fast_syscall_32+0xa4/0x450
 [<c149f6fa>] sysenter_past_esp+0x3b/0x5d
---[ end trace c2ecbc77760f10a0 ]---
Mapped at:
 [<c12b3183>] debug_dma_alloc_coherent+0x33/0x90
 [<f83e989c>] drm_pci_alloc+0x18c/0x1e0 [drm]
 [<f8acd59f>] intel_init_ring_buffer+0x2af/0x490 [i915]
 [<f8acd8b0>] intel_init_render_ring_buffer+0x130/0x750 [i915]
 [<f8aaea4e>] i915_gem_init_rings+0x1e/0x110 [i915]

v2: s/BUG_ON/WARN_ON/ since dim doens't like the former anymore

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Fixes: 5c6c600 ("drm/i915: Remove DRI1 ring accessors and API")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1452538112-5331-1-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Jun 14, 2016
commit 1900149 upstream.

Ezequiel reported that he's facing UBI going into read-only
mode after power cut. It turned out that this behavior happens
only when updating a static volume is interrupted and Fastmap is
used.

A possible trace can look like:
ubi0 warning: ubi_io_read_vid_hdr [ubi]: no VID header found at PEB 2323, only 0xFF bytes
ubi0 warning: ubi_eba_read_leb [ubi]: switch to read-only mode
CPU: 0 PID: 833 Comm: ubiupdatevol Not tainted 4.6.0-rc2-ARCH #4
Hardware name: SAMSUNG ELECTRONICS CO., LTD. 300E4C/300E5C/300E7C/NP300E5C-AD8AR, BIOS P04RAP 10/15/2012
0000000000000286 00000000eba949bd ffff8800c45a7b38 ffffffff8140d841
ffff8801964be000 ffff88018eaa4800 ffff8800c45a7bb8 ffffffffa003abf6
ffffffff850e2ac0 8000000000000163 ffff8801850e2ac0 ffff8801850e2ac0
Call Trace:
[<ffffffff8140d841>] dump_stack+0x63/0x82
[<ffffffffa003abf6>] ubi_eba_read_leb+0x486/0x4a0 [ubi]
[<ffffffffa00453b3>] ubi_check_volume+0x83/0xf0 [ubi]
[<ffffffffa0039d97>] ubi_open_volume+0x177/0x350 [ubi]
[<ffffffffa00375d8>] vol_cdev_open+0x58/0xb0 [ubi]
[<ffffffff8124b08e>] chrdev_open+0xae/0x1d0
[<ffffffff81243bcf>] do_dentry_open+0x1ff/0x300
[<ffffffff8124afe0>] ? cdev_put+0x30/0x30
[<ffffffff81244d36>] vfs_open+0x56/0x60
[<ffffffff812545f4>] path_openat+0x4f4/0x1190
[<ffffffff81256621>] do_filp_open+0x91/0x100
[<ffffffff81263547>] ? __alloc_fd+0xc7/0x190
[<ffffffff812450df>] do_sys_open+0x13f/0x210
[<ffffffff812451ce>] SyS_open+0x1e/0x20
[<ffffffff81a99e32>] entry_SYSCALL_64_fastpath+0x1a/0xa4

UBI checks static volumes for data consistency and reads the
whole volume upon first open. If the volume is found erroneous
users of UBI cannot read from it, but another volume update is
possible to fix it. The check is performed by running
ubi_eba_read_leb() on every allocated LEB of the volume.
For static volumes ubi_eba_read_leb() computes the checksum of all
data stored in a LEB. To verify the computed checksum it has to read
the LEB's volume header which stores the original checksum.
If the volume header is not found UBI treats this as fatal internal
error and switches to RO mode. If the UBI device was attached via a
full scan the assumption is correct, the volume header has to be
present as it had to be there while scanning to get known as mapped.
If the attach operation happened via Fastmap the assumption is no
longer correct. When attaching via Fastmap UBI learns the mapping
table from Fastmap's snapshot of the system state and not via a full
scan. It can happen that a LEB got unmapped after a Fastmap was
written to the flash. Then UBI can learn the LEB still as mapped and
accessing it returns only 0xFF bytes. As UBI is not a FTL it is
allowed to have mappings to empty PEBs, it assumes that the layer
above takes care of LEB accounting and referencing.
UBIFS does so using the LEB property tree (LPT).
For static volumes UBI blindly assumes that all LEBs are present and
therefore special actions have to be taken.

The described situation can happen when updating a static volume is
interrupted, either by a user or a power cut.
The volume update code first unmaps all LEBs of a volume and then
writes LEB by LEB. If the sequence of operations is interrupted UBI
detects this either by the absence of LEBs, no volume header present
at scan time, or corrupted payload, detected via checksum.
In the Fastmap case the former method won't trigger as no scan
happened and UBI automatically thinks all LEBs are present.
Only by reading data from a LEB it detects that the volume header is
missing and incorrectly treats this as fatal error.
To deal with the situation ubi_eba_read_leb() from now on checks
whether we attached via Fastmap and handles the absence of a
volume header like a data corruption error.
This way interrupted static volume updates will correctly get detected
also when Fastmap is used.

Reported-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Tested-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Jun 14, 2016
…eset_trx_ring

commit cf96893 upstream.

We can't use kfree_skb in irq disable context, because spin_lock_irqsave
make sure we are always in irq disable context, use dev_kfree_skb_irq
instead of kfree_skb is better than dev_kfree_skb_any.

This patch fix below kernel warning:
[ 7612.095528] ------------[ cut here ]------------
[ 7612.095546] WARNING: CPU: 3 PID: 4460 at kernel/softirq.c:150 __local_bh_enable_ip+0x58/0x80()
[ 7612.095550] Modules linked in: rtl8723be x86_pkg_temp_thermal btcoexist rtl_pci rtlwifi rtl8723_common
[ 7612.095567] CPU: 3 PID: 4460 Comm: ifconfig Tainted: G        W       4.4.0+ #4
[ 7612.095570] Hardware name: LENOVO 20DFA04FCD/20DFA04FCD, BIOS J5ET48WW (1.19 ) 08/27/2015
[ 7612.095574]  00000000 00000000 da37fc70 c12ce7c5 00000000 da37fca0 c104cc59 c19d4454
[ 7612.095584]  00000003 0000116c c19d4784 00000096 c10508a8 c10508a8 00000200 c1b42400
[ 7612.095594]  f29be780 da37fcb0 c104ccad 00000009 00000000 da37fcbc c10508a8 f21f08b8
[ 7612.095604] Call Trace:
[ 7612.095614]  [<c12ce7c5>] dump_stack+0x41/0x5c
[ 7612.095620]  [<c104cc59>] warn_slowpath_common+0x89/0xc0
[ 7612.095628]  [<c10508a8>] ? __local_bh_enable_ip+0x58/0x80
[ 7612.095634]  [<c10508a8>] ? __local_bh_enable_ip+0x58/0x80
[ 7612.095640]  [<c104ccad>] warn_slowpath_null+0x1d/0x20
[ 7612.095646]  [<c10508a8>] __local_bh_enable_ip+0x58/0x80
[ 7612.095653]  [<c16b7d34>] destroy_conntrack+0x64/0xa0
[ 7612.095660]  [<c16b300f>] nf_conntrack_destroy+0xf/0x20
[ 7612.095665]  [<c1677565>] skb_release_head_state+0x55/0xa0
[ 7612.095670]  [<c16775bb>] skb_release_all+0xb/0x20
[ 7612.095674]  [<c167760b>] __kfree_skb+0xb/0x60
[ 7612.095679]  [<c16776f0>] kfree_skb+0x30/0x70
[ 7612.095686]  [<f81b869d>] ? rtl_pci_reset_trx_ring+0x22d/0x370 [rtl_pci]
[ 7612.095692]  [<f81b869d>] rtl_pci_reset_trx_ring+0x22d/0x370 [rtl_pci]
[ 7612.095698]  [<f81b87f9>] rtl_pci_start+0x19/0x190 [rtl_pci]
[ 7612.095705]  [<f81970e6>] rtl_op_start+0x56/0x90 [rtlwifi]
[ 7612.095712]  [<c17e3f16>] drv_start+0x36/0xc0
[ 7612.095717]  [<c17f5ab3>] ieee80211_do_open+0x2d3/0x890
[ 7612.095725]  [<c16820fe>] ? call_netdevice_notifiers_info+0x2e/0x60
[ 7612.095730]  [<c17f60bd>] ieee80211_open+0x4d/0x50
[ 7612.095736]  [<c16891b3>] __dev_open+0xa3/0x130
[ 7612.095742]  [<c183fa53>] ? _raw_spin_unlock_bh+0x13/0x20
[ 7612.095748]  [<c1689499>] __dev_change_flags+0x89/0x140
[ 7612.095753]  [<c127c70d>] ? selinux_capable+0xd/0x10
[ 7612.095759]  [<c1689589>] dev_change_flags+0x29/0x60
[ 7612.095765]  [<c1700b93>] devinet_ioctl+0x553/0x670
[ 7612.095772]  [<c12db758>] ? _copy_to_user+0x28/0x40
[ 7612.095777]  [<c17018b5>] inet_ioctl+0x85/0xb0
[ 7612.095783]  [<c166e647>] sock_ioctl+0x67/0x260
[ 7612.095788]  [<c166e5e0>] ? sock_fasync+0x80/0x80
[ 7612.095795]  [<c115c99b>] do_vfs_ioctl+0x6b/0x550
[ 7612.095800]  [<c127c812>] ? selinux_file_ioctl+0x102/0x1e0
[ 7612.095807]  [<c10a8914>] ? timekeeping_suspend+0x294/0x320
[ 7612.095813]  [<c10a256a>] ? __hrtimer_run_queues+0x14a/0x210
[ 7612.095820]  [<c1276e24>] ? security_file_ioctl+0x34/0x50
[ 7612.095827]  [<c115cef0>] SyS_ioctl+0x70/0x80
[ 7612.095832]  [<c1001804>] do_fast_syscall_32+0x84/0x120
[ 7612.095839]  [<c183ff91>] sysenter_past_esp+0x36/0x55
[ 7612.095844] ---[ end trace 97e9c637a20e8348 ]---

Signed-off-by: Wang YanQing <udknight@gmail.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Sep 4, 2016
commit 86a574d upstream.

Don't allow RNDADDTOENTCNT or RNDADDENTROPY to accept a negative
entropy value.  It doesn't make any sense to subtract from the entropy
counter, and it can trigger a warning:

random: negative entropy/overflow: pool input count -40000
------------[ cut here ]------------
WARNING: CPU: 3 PID: 6828 at drivers/char/random.c:670[<      none
 >] credit_entropy_bits+0x21e/0xad0 drivers/char/random.c:670
Modules linked in:
CPU: 3 PID: 6828 Comm: a.out Not tainted 4.7.0-rc4+ #4
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 ffffffff880b58e0 ffff88005dd9fcb0 ffffffff82cc838f ffffffff87158b40
 fffffbfff1016b1c 0000000000000000 0000000000000000 ffffffff87158b40
 ffffffff83283dae 0000000000000009 ffff88005dd9fcf8 ffffffff8136d27f
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff82cc838f>] dump_stack+0x12e/0x18f lib/dump_stack.c:51
 [<ffffffff8136d27f>] __warn+0x19f/0x1e0 kernel/panic.c:516
 [<ffffffff8136d48c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:551
 [<ffffffff83283dae>] credit_entropy_bits+0x21e/0xad0 drivers/char/random.c:670
 [<     inline     >] credit_entropy_bits_safe drivers/char/random.c:734
 [<ffffffff8328785d>] random_ioctl+0x21d/0x250 drivers/char/random.c:1546
 [<     inline     >] vfs_ioctl fs/ioctl.c:43
 [<ffffffff8185316c>] do_vfs_ioctl+0x18c/0xff0 fs/ioctl.c:674
 [<     inline     >] SYSC_ioctl fs/ioctl.c:689
 [<ffffffff8185405f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:680
 [<ffffffff86a995c0>] entry_SYSCALL_64_fastpath+0x23/0xc1
arch/x86/entry/entry_64.S:207
---[ end trace 5d4902b2ba842f1f ]---

This was triggered using the test program:

// autogenerated by syzkaller (http://github.com/google/syzkaller)

int main() {
        int fd = open("/dev/random", O_RDWR);
        int val = -5000;
        ioctl(fd, RNDADDTOENTCNT, &val);
        return 0;
}

It's harmless in that (a) only root can trigger it, and (b) after
complaining the code never does let the entropy count go negative, but
it's better to simply not allow this userspace from passing in a
negative entropy value altogether.

Google-Bug-Id: #29575089
Reported-By: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Oct 15, 2016
[ Upstream commit 94d9f1c ]

Panic occurs when issuing "cat /proc/net/route" whilst
populating FIB with > 1M routes.

Use of cached node pointer in fib_route_get_idx is unsafe.

 BUG: unable to handle kernel paging request at ffffc90001630024
 IP: [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0
 PGD 11b08d067 PUD 11b08e067 PMD dac4b067 PTE 0
 Oops: 0000 [#1] SMP
 Modules linked in: nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscac
 snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep virti
 acpi_cpufreq button parport_pc ppdev lp parport autofs4 ext4 crc16 mbcache jbd
tio_ring virtio floppy uhci_hcd ehci_hcd usbcore usb_common libata scsi_mod
 CPU: 1 PID: 785 Comm: cat Not tainted 4.2.0-rc8+ #4
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
 task: ffff8800da1c0bc0 ti: ffff88011a05c000 task.ti: ffff88011a05c000
 RIP: 0010:[<ffffffff814cf6a0>]  [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0
 RSP: 0018:ffff88011a05fda0  EFLAGS: 00010202
 RAX: ffff8800d8a40c00 RBX: ffff8800da4af940 RCX: ffff88011a05ff20
 RDX: ffffc90001630020 RSI: 0000000001013531 RDI: ffff8800da4af950
 RBP: 0000000000000000 R08: ffff8800da1f9a00 R09: 0000000000000000
 R10: ffff8800db45b7e4 R11: 0000000000000246 R12: ffff8800da4af950
 R13: ffff8800d97a74c0 R14: 0000000000000000 R15: ffff8800d97a7480
 FS:  00007fd3970e0700(0000) GS:ffff88011fd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: ffffc90001630024 CR3: 000000011a7e4000 CR4: 00000000000006e0
 Stack:
  ffffffff814d00d3 0000000000000000 ffff88011a05ff20 ffff8800da1f9a00
  ffffffff811dd8b9 0000000000000800 0000000000020000 00007fd396f35000
  ffffffff811f8714 0000000000003431 ffffffff8138dce0 0000000000000f80
 Call Trace:
  [<ffffffff814d00d3>] ? fib_route_seq_start+0x93/0xc0
  [<ffffffff811dd8b9>] ? seq_read+0x149/0x380
  [<ffffffff811f8714>] ? fsnotify+0x3b4/0x500
  [<ffffffff8138dce0>] ? process_echoes+0x70/0x70
  [<ffffffff8121cfa7>] ? proc_reg_read+0x47/0x70
  [<ffffffff811bb823>] ? __vfs_read+0x23/0xd0
  [<ffffffff811bbd42>] ? rw_verify_area+0x52/0xf0
  [<ffffffff811bbe61>] ? vfs_read+0x81/0x120
  [<ffffffff811bcbc2>] ? SyS_read+0x42/0xa0
  [<ffffffff81549ab2>] ? entry_SYSCALL_64_fastpath+0x16/0x75
 Code: 48 85 c0 75 d8 f3 c3 31 c0 c3 f3 c3 66 66 66 66 66 66 2e 0f 1f 84 00 00
a 04 89 f0 33 02 44 89 c9 48 d3 e8 0f b6 4a 05 49 89
 RIP  [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0
  RSP <ffff88011a05fda0>
 CR2: ffffc90001630024

Signed-off-by: Dave Forster <dforster@brocade.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
dlech pushed a commit that referenced this pull request Nov 16, 2016
commit 420902c upstream.

If we hold the superblock lock while calling reiserfs_quota_on_mount(), we can
deadlock our own worker - mount blocks kworker/3:2, sleeps forever more.

crash> ps|grep UN
    715      2   3  ffff880220734d30  UN   0.0       0      0  [kworker/3:2]
   9369   9341   2  ffff88021ffb7560  UN   1.3  493404 123184  Xorg
   9665   9664   3  ffff880225b92ab0  UN   0.0   47368    812  udisks-daemon
  10635  10403   3  ffff880222f22c70  UN   0.0   14904    936  mount
crash> bt ffff880220734d30
PID: 715    TASK: ffff880220734d30  CPU: 3   COMMAND: "kworker/3:2"
 #0 [ffff8802244c3c20] schedule at ffffffff8144584b
 #1 [ffff8802244c3cc8] __rt_mutex_slowlock at ffffffff814472b3
 #2 [ffff8802244c3d28] rt_mutex_slowlock at ffffffff814473f5
 #3 [ffff8802244c3dc8] reiserfs_write_lock at ffffffffa05f28fd [reiserfs]
 #4 [ffff8802244c3de8] flush_async_commits at ffffffffa05ec91d [reiserfs]
 #5 [ffff8802244c3e08] process_one_work at ffffffff81073726
 #6 [ffff8802244c3e68] worker_thread at ffffffff81073eba
 #7 [ffff8802244c3ec8] kthread at ffffffff810782e0
 #8 [ffff8802244c3f48] kernel_thread_helper at ffffffff81450064
crash> rd ffff8802244c3cc8 10
ffff8802244c3cc8:  ffffffff814472b3 ffff880222f23250   .rD.....P2."....
ffff8802244c3cd8:  0000000000000000 0000000000000286   ................
ffff8802244c3ce8:  ffff8802244c3d30 ffff880220734d80   0=L$.....Ms ....
ffff8802244c3cf8:  ffff880222e8f628 0000000000000000   (.."............
ffff8802244c3d08:  0000000000000000 0000000000000002   ................
crash> struct rt_mutex ffff880222e8f628
struct rt_mutex {
  wait_lock = {
    raw_lock = {
      slock = 65537
    }
  },
  wait_list = {
    node_list = {
      next = 0xffff8802244c3d48,
      prev = 0xffff8802244c3d48
    }
  },
  owner = 0xffff880222f22c71,
  save_state = 0
}
crash> bt 0xffff880222f22c70
PID: 10635  TASK: ffff880222f22c70  CPU: 3   COMMAND: "mount"
 #0 [ffff8802216a9868] schedule at ffffffff8144584b
 #1 [ffff8802216a9910] schedule_timeout at ffffffff81446865
 #2 [ffff8802216a99a0] wait_for_common at ffffffff81445f74
 #3 [ffff8802216a9a30] flush_work at ffffffff810712d3
 #4 [ffff8802216a9ab0] schedule_on_each_cpu at ffffffff81074463
 #5 [ffff8802216a9ae0] invalidate_bdev at ffffffff81178aba
 #6 [ffff8802216a9af0] vfs_load_quota_inode at ffffffff811a3632
 #7 [ffff8802216a9b50] dquot_quota_on_mount at ffffffff811a375c
 #8 [ffff8802216a9b80] finish_unfinished at ffffffffa05dd8b0 [reiserfs]
 #9 [ffff8802216a9cc0] reiserfs_fill_super at ffffffffa05de825 [reiserfs]
    RIP: 00007f7b9303997a  RSP: 00007ffff443c7a8  RFLAGS: 00010202
    RAX: 00000000000000a5  RBX: ffffffff8144ef12  RCX: 00007f7b932e9ee0
    RDX: 00007f7b93d9a400  RSI: 00007f7b93d9a3e0  RDI: 00007f7b93d9a3c0
    RBP: 00007f7b93d9a2c0   R8: 00007f7b93d9a550   R9: 0000000000000001
    R10: ffffffffc0ed040e  R11: 0000000000000202  R12: 000000000000040e
    R13: 0000000000000000  R14: 00000000c0ed040e  R15: 00007ffff443ca20
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Mike Galbraith <mgalbraith@suse.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request Dec 5, 2016
commit 1c3c909 broke PAE40. Macro pfn_pte(pfn, prot) creates paddr
from pfn, but the page shift was getting truncated to 32 bits since we lost
the proper cast to 64 bits (for PAE400

Instead of reverting that commit, use a better helper which is 32/64 bits
safe just like ARM implementation.

Fixes: 1c3c909 ("ARC: mm: fix build breakage with STRICT_MM_TYPECHECKS")
Cc: <stable@vger.kernel.org>   ev3dev#4.4+
Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
[vgupta: massaged changelog]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
dlech pushed a commit that referenced this pull request Sep 9, 2017
… crash

commit 96b7774 upstream.

Commit:

  2f5177f ("sched/cgroup: Fix/cleanup cgroup teardown/init")

.. moved sched_online_group() from css_online() to css_alloc().
It exposes half-baked task group into global lists before initializing
generic cgroup stuff.

LTP testcase (third in cgroup_regression_test) written for testing
similar race in kernels 2.6.26-2.6.28 easily triggers this oops:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  IP: kernfs_path_from_node_locked+0x260/0x320
  CPU: 1 PID: 30346 Comm: cat Not tainted 4.10.0-rc5-test #4
  Call Trace:
  ? kernfs_path_from_node+0x4f/0x60
  kernfs_path_from_node+0x3e/0x60
  print_rt_rq+0x44/0x2b0
  print_rt_stats+0x7a/0xd0
  print_cpu+0x2fc/0xe80
  ? __might_sleep+0x4a/0x80
  sched_debug_show+0x17/0x30
  seq_read+0xf2/0x3b0
  proc_reg_read+0x42/0x70
  __vfs_read+0x28/0x130
  ? security_file_permission+0x9b/0xc0
  ? rw_verify_area+0x4e/0xb0
  vfs_read+0xa5/0x170
  SyS_read+0x46/0xa0
  entry_SYSCALL_64_fastpath+0x1e/0xad

Here the task group is already linked into the global RCU-protected 'task_groups'
list, but the css->cgroup pointer is still NULL.

This patch reverts this chunk and moves online back to css_online().

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 2f5177f ("sched/cgroup: Fix/cleanup cgroup teardown/init")
Link: http://lkml.kernel.org/r/148655324740.424917.5302984537258726349.stgit@buzz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Sep 9, 2017
commit 89affbf upstream.

In codepaths that use the begin/retry interface for reading
mems_allowed_seq with irqs disabled, there exists a race condition that
stalls the patch process after only modifying a subset of the
static_branch call sites.

This problem manifested itself as a deadlock in the slub allocator,
inside get_any_partial.  The loop reads mems_allowed_seq value (via
read_mems_allowed_begin), performs the defrag operation, and then
verifies the consistency of mem_allowed via the read_mems_allowed_retry
and the cookie returned by xxx_begin.

The issue here is that both begin and retry first check if cpusets are
enabled via cpusets_enabled() static branch.  This branch can be
rewritted dynamically (via cpuset_inc) if a new cpuset is created.  The
x86 jump label code fully synchronizes across all CPUs for every entry
it rewrites.  If it rewrites only one of the callsites (specifically the
one in read_mems_allowed_retry) and then waits for the
smp_call_function(do_sync_core) to complete while a CPU is inside the
begin/retry section with IRQs off and the mems_allowed value is changed,
we can hang.

This is because begin() will always return 0 (since it wasn't patched
yet) while retry() will test the 0 against the actual value of the seq
counter.

The fix is to use two different static keys: one for begin
(pre_enable_key) and one for retry (enable_key).  In cpuset_inc(), we
first bump the pre_enable key to ensure that cpuset_mems_allowed_begin()
always return a valid seqcount if are enabling cpusets.  Similarly, when
disabling cpusets via cpuset_dec(), we first ensure that callers of
cpuset_mems_allowed_retry() will start ignoring the seqcount value
before we let cpuset_mems_allowed_begin() return 0.

The relevant stack traces of the two stuck threads:

  CPU: 1 PID: 1415 Comm: mkdir Tainted: G L  4.9.36-00104-g540c51286237 #4
  Hardware name: Default string Default string/Hardware, BIOS 4.29.1-20170526215256 05/26/2017
  task: ffff8817f9c28000 task.stack: ffffc9000ffa4000
  RIP: smp_call_function_many+0x1f9/0x260
  Call Trace:
    smp_call_function+0x3b/0x70
    on_each_cpu+0x2f/0x90
    text_poke_bp+0x87/0xd0
    arch_jump_label_transform+0x93/0x100
    __jump_label_update+0x77/0x90
    jump_label_update+0xaa/0xc0
    static_key_slow_inc+0x9e/0xb0
    cpuset_css_online+0x70/0x2e0
    online_css+0x2c/0xa0
    cgroup_apply_control_enable+0x27f/0x3d0
    cgroup_mkdir+0x2b7/0x420
    kernfs_iop_mkdir+0x5a/0x80
    vfs_mkdir+0xf6/0x1a0
    SyS_mkdir+0xb7/0xe0
    entry_SYSCALL_64_fastpath+0x18/0xad

  ...

  CPU: 2 PID: 1 Comm: init Tainted: G L  4.9.36-00104-g540c51286237 #4
  Hardware name: Default string Default string/Hardware, BIOS 4.29.1-20170526215256 05/26/2017
  task: ffff8818087c0000 task.stack: ffffc90000030000
  RIP: int3+0x39/0x70
  Call Trace:
    <#DB> ? ___slab_alloc+0x28b/0x5a0
    <EOE> ? copy_process.part.40+0xf7/0x1de0
    __slab_alloc.isra.80+0x54/0x90
    copy_process.part.40+0xf7/0x1de0
    copy_process.part.40+0xf7/0x1de0
    kmem_cache_alloc_node+0x8a/0x280
    copy_process.part.40+0xf7/0x1de0
    _do_fork+0xe7/0x6c0
    _raw_spin_unlock_irq+0x2d/0x60
    trace_hardirqs_on_caller+0x136/0x1d0
    entry_SYSCALL_64_fastpath+0x5/0xad
    do_syscall_64+0x27/0x350
    SyS_clone+0x19/0x20
    do_syscall_64+0x60/0x350
    entry_SYSCALL64_slow_path+0x25/0x25

Link: http://lkml.kernel.org/r/20170731040113.14197-1-dmitriyz@waymo.com
Fixes: 46e700a ("mm, page_alloc: remove unnecessary taking of a seqlock when cpusets are disabled")
Signed-off-by: Dima Zavin <dmitriyz@waymo.com>
Reported-by: Cliff Spradlin <cspradlin@waymo.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christopher Lameter <cl@linux.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request Jan 12, 2018
clk_change_rate() propagates rate change down to all its children. Such
operation requires managing proper runtime PM state of each child, what
was missing. Add needed calls to clk_pm_runtime*() to ensure that
set_rate() clock callback is called on runtime active clock.

This fixes following issue found on Exynos5433 TM2 board with devfreq
enabled:

Synchronous External Abort: synchronous external abort (0x96000210) at 0xffffff80093f5600
Internal error: : 96000210 [ev3dev#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 5 Comm: kworker/u16:0 Not tainted 4.15.0-rc1-next-20171129+ ev3dev#4
Hardware name: Samsung TM2 board (DT)
Workqueue: devfreq_wq devfreq_monitor
task: ffffffc0ca96b600 task.stack: ffffff80093a8000
pstate: a0000085 (NzCv daIf -PAN -UAO)
pc : clk_divider_set_rate+0x54/0x118
lr : clk_divider_set_rate+0x44/0x118
...
Process kworker/u16:0 (pid: 5, stack limit = 0xffffff80093a8000)
Call trace:
 clk_divider_set_rate+0x54/0x118
 clk_change_rate+0xfc/0x4e0
 clk_change_rate+0x1f0/0x4e0
 clk_change_rate+0x1f0/0x4e0
 clk_change_rate+0x1f0/0x4e0
 clk_core_set_rate_nolock+0x138/0x148
 clk_set_rate+0x28/0x50
 exynos_bus_passive_target+0x6c/0x11c
 update_devfreq_passive+0x58/0xb4
 devfreq_passive_notifier_call+0x50/0x5c
 notifier_call_chain+0x4c/0x88
 __srcu_notifier_call_chain+0x54/0x80
 srcu_notifier_call_chain+0x14/0x1c
 update_devfreq+0x100/0x1b4
 devfreq_monitor+0x2c/0x88
 process_one_work+0x148/0x3d8
 worker_thread+0x13c/0x3f8
 kthread+0x100/0x12c
 ret_from_fork+0x10/0x18

Reported-by: Chanwoo Choi <cw00.choi@samsung.com>
Fixes: 9a34b45 ("clk: Add support for runtime PM")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request Jan 12, 2018
Loading hci_bcm with CONFIG_GPIOLIB=n results in the following splat
when calling gpiod_to_irq() from bcm_get_resources():

    WARNING: CPU: 0 PID: 1006 at ./include/linux/gpio/consumer.h:450 bcm_get_resources+0x50/0x80
    CPU: 0 PID: 1006 Comm: kworker/u8:4 Tainted: G       A         4.15.0-rc4custom+ ev3dev#4
    Hardware name: Apple Inc. MacBook8,1/Mac-BE0E8AC46FE800CC, BIOS MB81.88Z.0168.B00.1708080033 08/08/2017
    Call Trace:
    bcm_serdev_probe+0x8b/0xc0
    driver_probe_device+0x202/0x310
    __driver_attach+0x85/0x90
    ? driver_probe_device+0x310/0x310
    bus_for_each_dev+0x57/0x80
    async_run_entry_fn+0x2c/0xd0
    process_one_work+0x1d2/0x3d0
    worker_thread+0x26/0x3c0
    ? process_one_work+0x3d0/0x3d0
    kthread+0x10c/0x130
    ? kthread_create_on_node+0x40/0x40
    ret_from_fork+0x1f/0x30

We could call gpiod_to_irq() only if IS_ENABLED(CONFIG_GPIOLIB) but
without GPIOLIB, the driver's power saving features can't be used,
so selecting GPIOLIB seems more appropriate.

The same issue is present in hci_intel.c and hci_nokia.c, fix those up
as well.

Reported-by: Max Shavrick <mxms@me.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request Mar 5, 2018
ACM driver may accept data to transmit while system is not fully
resumed. In this case ACM driver buffers data and prepare URBs
on usb anchor list.
There is a little chance that two tasks put a char and initiate
acm_tty_flush_chars(). In such a case, driver will put one URB
twice on usb anchor list.
This patch also reset length of data before resue of a buffer.
This not only prevent sending rubbish, but also lower risc of race.

Without this patch we hit following kernel panic in one of our
stabilty/stress tests.

[   46.884442] *list_add double add*: new=ffff9b2ab7289330, prev=ffff9b2ab7289330, next=ffff9b2ab81e28e0.
[   46.884476] Modules linked in: hci_uart btbcm bluetooth rfkill_gpio igb_avb(O) cfg80211 snd_soc_sst_bxt_tdf8532 snd_soc_skl snd_soc_skl_ipc snd_soc_sst_ipc snd_soc_sst_dsp snd_soc_sst_acpi snd_soc_sst_match snd_hda_ext_core snd_hda_core trusty_timer trusty_wall trusty_log trusty_virtio trusty_ipc trusty_mem trusty_irq trusty virtio_ring virtio intel_ipu4_mmu_bxtB0 lib2600_mod_bxtB0 intel_ipu4_isys_mod_bxtB0 lib2600psys_mod_bxtB0 intel_ipu4_psys_mod_bxtB0 intel_ipu4_mod_bxtB0 intel_ipu4_wrapper_bxtB0 intel_ipu4_acpi videobuf2_dma_contig as3638 dw9714 lm3643 crlmodule smiapp smiapp_pll
[   46.884480] CPU: 1 PID: 33 Comm: kworker/u8:1 Tainted: G     U  W  O    4.9.56-quilt-2e5dc0ac-g618ed69ced6e-dirty ev3dev#4
[   46.884489] Workqueue: events_unbound flush_to_ldisc
[   46.884494]  ffffb98ac012bb08 ffffffffad3e82e5 ffffb98ac012bb58 0000000000000000
[   46.884497]  ffffb98ac012bb48 ffffffffad0a23d1 00000024ad6374dd ffff9b2ab7289330
[   46.884500]  ffff9b2ab81e28e0 ffff9b2ab7289330 0000000000000002 0000000000000000
[   46.884501] Call Trace:
[   46.884507]  [<ffffffffad3e82e5>] dump_stack+0x67/0x92
[   46.884511]  [<ffffffffad0a23d1>] __warn+0xd1/0xf0
[   46.884513]  [<ffffffffad0a244f>] warn_slowpath_fmt+0x5f/0x80
[   46.884516]  [<ffffffffad407443>] __list_add+0xb3/0xc0
[   46.884521]  [<ffffffffad71133c>] *usb_anchor_urb*+0x4c/0xa0
[   46.884524]  [<ffffffffad782c6f>] *acm_tty_flush_chars*+0x8f/0xb0
[   46.884527]  [<ffffffffad782cd1>] *acm_tty_put_char*+0x41/0x100
[   46.884530]  [<ffffffffad4ced34>] tty_put_char+0x24/0x40
[   46.884533]  [<ffffffffad4d3bf5>] do_output_char+0xa5/0x200
[   46.884535]  [<ffffffffad4d3e98>] __process_echoes+0x148/0x290
[   46.884538]  [<ffffffffad4d654c>] n_tty_receive_buf_common+0x57c/0xb00
[   46.884541]  [<ffffffffad4d6ae4>] n_tty_receive_buf2+0x14/0x20
[   46.884543]  [<ffffffffad4d9662>] tty_ldisc_receive_buf+0x22/0x50
[   46.884545]  [<ffffffffad4d9c05>] flush_to_ldisc+0xc5/0xe0
[   46.884549]  [<ffffffffad0bcfe8>] process_one_work+0x148/0x440
[   46.884551]  [<ffffffffad0bdc19>] worker_thread+0x69/0x4a0
[   46.884554]  [<ffffffffad0bdbb0>] ? max_active_store+0x80/0x80
[   46.884556]  [<ffffffffad0c2e10>] kthread+0x110/0x130
[   46.884559]  [<ffffffffad0c2d00>] ? kthread_park+0x60/0x60
[   46.884563]  [<ffffffffadad9917>] ret_from_fork+0x27/0x40
[   46.884566] ---[ end trace 3bd599058b8a9eb3 ]---

Signed-off-by: Dominik Bozek <dominikx.bozek@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request Mar 5, 2018
One I2C bus on my Atom E3845 board has been broken since 4.9.
It has two devices, both declared by ACPI and with built-in drivers.

There are two back-to-back transactions originating from the kernel, one
targeting each device. The first transaction works, the second one locks
up the I2C controller. The controller never recovers.

These kernel logs show up whenever an I2C transaction is attempted after
this failure.
i2c-designware-pci 0000:00:18.3: timeout in disabling adapter
i2c-designware-pci 0000:00:18.3: timeout waiting for bus ready

Waiting for the I2C controller status to indicate that it is enabled
before programming it fixes the issue.

I have tested this patch on 4.14 and 4.15.

Fixes: commit 2702ea7 ("i2c: designware: wait for disable/enable only if necessary")
Cc: linux-stable <stable@vger.kernel.org> ev3dev#4.13+
Signed-off-by: Ben Gardner <gardner.ben@gmail.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request Mar 5, 2018
It was reported by Sergey Senozhatsky that if THP (Transparent Huge
Page) and frontswap (via zswap) are both enabled, when memory goes low
so that swap is triggered, segfault and memory corruption will occur in
random user space applications as follow,

kernel: urxvt[338]: segfault at 20 ip 00007fc08889ae0d sp 00007ffc73a7fc40 error 6 in libc-2.26.so[7fc08881a000+1ae000]
 #0  0x00007fc08889ae0d _int_malloc (libc.so.6)
 ev3dev#1  0x00007fc08889c2f3 malloc (libc.so.6)
 ev3dev#2  0x0000560e6004bff7 _Z14rxvt_wcstoutf8PKwi (urxvt)
 ev3dev#3  0x0000560e6005e75c n/a (urxvt)
 ev3dev#4  0x0000560e6007d9f1 _ZN16rxvt_perl_interp6invokeEP9rxvt_term9hook_typez (urxvt)
 ev3dev#5  0x0000560e6003d988 _ZN9rxvt_term9cmd_parseEv (urxvt)
 ev3dev#6  0x0000560e60042804 _ZN9rxvt_term6pty_cbERN2ev2ioEi (urxvt)
 ev3dev#7  0x0000560e6005c10f _Z17ev_invoke_pendingv (urxvt)
 ev3dev#8  0x0000560e6005cb55 ev_run (urxvt)
 ev3dev#9  0x0000560e6003b9b9 main (urxvt)
 ev3dev#10 0x00007fc08883af4a __libc_start_main (libc.so.6)
 ev3dev#11 0x0000560e6003f9da _start (urxvt)

After bisection, it was found the first bad commit is bd4c82c ("mm,
THP, swap: delay splitting THP after swapped out").

The root cause is as follows:

When the pages are written to swap device during swapping out in
swap_writepage(), zswap (fontswap) is tried to compress the pages to
improve performance.  But zswap (frontswap) will treat THP as a normal
page, so only the head page is saved.  After swapping in, tail pages
will not be restored to their original contents, causing memory
corruption in the applications.

This is fixed by refusing to save page in the frontswap store functions
if the page is a THP.  So that the THP will be swapped out to swap
device.

Another choice is to split THP if frontswap is enabled.  But it is found
that the frontswap enabling isn't flexible.  For example, if
CONFIG_ZSWAP=y (cannot be module), frontswap will be enabled even if
zswap itself isn't enabled.

Frontswap has multiple backends, to make it easy for one backend to
enable THP support, the THP checking is put in backend frontswap store
functions instead of the general interfaces.

Link: http://lkml.kernel.org/r/20180209084947.22749-1-ying.huang@intel.com
Fixes: bd4c82c ("mm, THP, swap: delay splitting THP after swapped out")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Suggested-by: Minchan Kim <minchan@kernel.org>	[put THP checking in backend]
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Shaohua Li <shli@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: <stable@vger.kernel.org>	[4.14]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request Mar 16, 2018
Reported by syzkaller:

   WARNING: CPU: 6 PID: 2434 at arch/x86/kvm/vmx.c:6660 handle_ept_misconfig+0x54/0x1e0 [kvm_intel]
   CPU: 6 PID: 2434 Comm: repro_test Not tainted 4.15.0+ ev3dev#4
   RIP: 0010:handle_ept_misconfig+0x54/0x1e0 [kvm_intel]
   Call Trace:
    vmx_handle_exit+0xbd/0xe20 [kvm_intel]
    kvm_arch_vcpu_ioctl_run+0xdaf/0x1d50 [kvm]
    kvm_vcpu_ioctl+0x3e9/0x720 [kvm]
    do_vfs_ioctl+0xa4/0x6a0
    SyS_ioctl+0x79/0x90
    entry_SYSCALL_64_fastpath+0x25/0x9c

The testcase creates a first thread to issue KVM_SMI ioctl, and then creates
a second thread to mmap and operate on the same vCPU.  This triggers a race
condition when running the testcase with multiple threads. Sometimes one thread
exits with a triple fault while another thread mmaps and operates on the same
vCPU.  Because CS=0x3000/IP=0x8000 is not mapped, accessing the SMI handler
results in an EPT misconfig. This patch fixes it by returning RET_PF_EMULATE
in kvm_handle_bad_page(), which will go on to cause an emulation failure and an
exit with KVM_EXIT_INTERNAL_ERROR.

Reported-by: syzbot+c1d9517cab094dae65e446c0c5b4de6c40f4dc58@syzkaller.appspotmail.com
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request Mar 16, 2018
This patch fixes NULL pointer crash due to active timer running for abort
IOCB.

From crash dump analysis it was discoverd that get_next_timer_interrupt()
encountered a corrupted entry on the timer list.

 ev3dev#9 [ffff95e1f6f0fd40] page_fault at ffffffff914fe8f8
    [exception RIP: get_next_timer_interrupt+440]
    RIP: ffffffff90ea3088  RSP: ffff95e1f6f0fdf0  RFLAGS: 00010013
    RAX: ffff95e1f6451028  RBX: 000218e2389e5f40  RCX: 00000001232ad600
    RDX: 0000000000000001  RSI: ffff95e1f6f0fdf0  RDI: 0000000001232ad6
    RBP: ffff95e1f6f0fe40   R8: ffff95e1f6451188   R9: 0000000000000001
    R10: 0000000000000016  R11: 0000000000000016  R12: 00000001232ad5f6
    R13: ffff95e1f6450000  R14: ffff95e1f6f0fdf8  R15: ffff95e1f6f0fe10
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018

Looking at the assembly of get_next_timer_interrupt(), address came
from %r8 (ffff95e1f6451188) which is pointing to list_head with single
entry at ffff95e5ff621178.

 0xffffffff90ea307a <get_next_timer_interrupt+426>:      mov    (%r8),%rdx
 0xffffffff90ea307d <get_next_timer_interrupt+429>:      cmp    %r8,%rdx
 0xffffffff90ea3080 <get_next_timer_interrupt+432>:      je     0xffffffff90ea30a7 <get_next_timer_interrupt+471>
 0xffffffff90ea3082 <get_next_timer_interrupt+434>:      nopw   0x0(%rax,%rax,1)
 0xffffffff90ea3088 <get_next_timer_interrupt+440>:      testb  $0x1,0x18(%rdx)

 crash> rd ffff95e1f6451188 10
 ffff95e1f6451188:  ffff95e5ff621178 ffff95e5ff621178   x.b.....x.b.....
 ffff95e1f6451198:  ffff95e1f6451198 ffff95e1f6451198   ..E.......E.....
 ffff95e1f64511a8:  ffff95e1f64511a8 ffff95e1f64511a8   ..E.......E.....
 ffff95e1f64511b8:  ffff95e77cf509a0 ffff95e77cf509a0   ...|.......|....
 ffff95e1f64511c8:  ffff95e1f64511c8 ffff95e1f64511c8   ..E.......E.....

 crash> rd ffff95e5ff621178 10
 ffff95e5ff621178:  0000000000000001 ffff95e15936aa00   ..........6Y....
 ffff95e5ff621188:  0000000000000000 00000000ffffffff   ................
 ffff95e5ff621198:  00000000000000a0 0000000000000010   ................
 ffff95e5ff6211a8:  ffff95e5ff621198 000000000000000c   ..b.............
 ffff95e5ff6211b8:  00000f5800000000 ffff95e751f8d720   ....X... ..Q....

 ffff95e5ff621178 belongs to freed mempool object at ffff95e5ff621080.

 CACHE            NAME                 OBJSIZE  ALLOCATED     TOTAL  SLABS  SSIZE
 ffff95dc7fd74d00 mnt_cache                384      19785     24948    594    16k
   SLAB              MEMORY            NODE  TOTAL  ALLOCATED  FREE
   ffffdc5dabfd8800  ffff95e5ff620000     1     42         29    13
   FREE / [ALLOCATED]
    ffff95e5ff621080  (cpu 6 cache)

Examining the contents of that memory reveals a pointer to a constant string
in the driver, "abort\0", which is set by qla24xx_async_abort_cmd().

 crash> rd ffffffffc059277c 20
 ffffffffc059277c:  6e490074726f6261 0074707572726574   abort.Interrupt.
 ffffffffc059278c:  00676e696c6c6f50 6920726576697244   Polling.Driver i
 ffffffffc059279c:  646f6d207325206e 6974736554000a65   n %s mode..Testi
 ffffffffc05927ac:  636976656420676e 786c252074612065   ng device at %lx
 ffffffffc05927bc:  6b63656843000a2e 646f727020676e69   ...Checking prod
 ffffffffc05927cc:  6f20444920746375 0a2e706968632066   uct ID of chip..
 ffffffffc05927dc:  5120646e756f4600 204130303232414c   .Found QLA2200A
 ffffffffc05927ec:  43000a2e70696843 20676e696b636568   Chip...Checking
 ffffffffc05927fc:  65786f626c69616d 6c636e69000a2e73   mailboxes...incl
 ffffffffc059280c:  756e696c2f656475 616d2d616d642f78   ude/linux/dma-ma

 crash> struct -ox srb_iocb
 struct srb_iocb {
           union {
               struct {...} logio;
               struct {...} els_logo;
               struct {...} tmf;
               struct {...} fxiocb;
               struct {...} abt;
               struct ct_arg ctarg;
               struct {...} mbx;
               struct {...} nack;
    [0x0 ] } u;
    [0xb8] struct timer_list timer;
    [0x108] void (*timeout)(void *);
 }
 SIZE: 0x110

 crash> ! bc
 ibase=16
 obase=10
 B8+40
 F8

The object is a srb_t, and at offset 0xf8 within that structure
(i.e. ffff95e5ff621080 + f8 -> ffff95e5ff621178) is a struct timer_list.

Cc: <stable@vger.kernel.org> ev3dev#4.4+
Fixes: 4440e46 ("[SCSI] qla2xxx: Add IOCB Abort command asynchronous handling.")
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request Mar 16, 2018
iproute2 print_skbmod() prints the configured ethertype using format 0x%X:
therefore, test 9aa8 systematically fails, because it configures action ev3dev#4
using ethertype 0x0031, and expects 0x0031 when it reads it back. Changing
the expected value to 0x31 lets the test result 'not ok' become 'ok'.

tested with:
 # ./tdc.py -e 9aa8
 Test 9aa8: Get a single skbmod action from a list
 All test results:

 1..1
 ok 1 9aa8 Get a single skbmod action from a list

Fixes: cf797ac ("tc-testing: Add test cases for police and skbmod")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request Mar 16, 2018
Currently we can crash perf record when running in pipe mode, like:

  $ perf record ls | perf report
  # To display the perf.data header info, please use --header/--header-only options.
  #
  perf: Segmentation fault
  Error:
  The - file has no samples!

The callstack of the crash is:

    0x0000000000515242 in perf_event__synthesize_event_update_name
  3513            ev = event_update_event__new(len + 1, PERF_EVENT_UPDATE__NAME, evsel->id[0]);
  (gdb) bt
  #0  0x0000000000515242 in perf_event__synthesize_event_update_name
  ev3dev#1  0x00000000005158a4 in perf_event__synthesize_extra_attr
  ev3dev#2  0x0000000000443347 in record__synthesize
  ev3dev#3  0x00000000004438e3 in __cmd_record
  ev3dev#4  0x000000000044514e in cmd_record
  ev3dev#5  0x00000000004cbc95 in run_builtin
  ev3dev#6  0x00000000004cbf02 in handle_internal_command
  ev3dev#7  0x00000000004cc054 in run_argv
  ev3dev#8  0x00000000004cc422 in main

The reason of the crash is that the evsel does not have ids array
allocated and the pipe's synthesize code tries to access it.

We don't force evsel ids allocation when we have single event, because
it's not needed. However we need it when we are in pipe mode even for
single event as a key for evsel update event.

Fixing this by forcing evsel ids allocation event for single event, when
we are in pipe mode.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180302161354.30192-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request May 3, 2018
Although we've implemented PSCI 0.1, 0.2 and 1.0, we expose either 0.1
or 1.0 to a guest, defaulting to the latest version of the PSCI
implementation that is compatible with the requested version. This is
no different from doing a firmware upgrade on KVM.

But in order to give a chance to hypothetical badly implemented guests
that would have a fit by discovering something other than PSCI 0.2,
let's provide a new API that allows userspace to pick one particular
version of the API.

This is implemented as a new class of "firmware" registers, where
we expose the PSCI version. This allows the PSCI version to be
save/restored as part of a guest migration, and also set to
any supported version if the guest requires it.

Cc: stable@vger.kernel.org ev3dev#4.16
Reviewed-by: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
dlech pushed a commit that referenced this pull request May 5, 2018
[ Upstream commit 2c0aa08 ]

Scenario:
1. Port down and do fail over
2. Ap do rds_bind syscall

PID: 47039  TASK: ffff89887e2fe640  CPU: 47  COMMAND: "kworker/u:6"
 #0 [ffff898e35f159f0] machine_kexec at ffffffff8103abf9
 #1 [ffff898e35f15a60] crash_kexec at ffffffff810b96e3
 #2 [ffff898e35f15b30] oops_end at ffffffff8150f518
 #3 [ffff898e35f15b60] no_context at ffffffff8104854c
 #4 [ffff898e35f15ba0] __bad_area_nosemaphore at ffffffff81048675
 #5 [ffff898e35f15bf0] bad_area_nosemaphore at ffffffff810487d3
 #6 [ffff898e35f15c00] do_page_fault at ffffffff815120b8
 #7 [ffff898e35f15d10] page_fault at ffffffff8150ea95
    [exception RIP: unknown or invalid address]
    RIP: 0000000000000000  RSP: ffff898e35f15dc8  RFLAGS: 00010282
    RAX: 00000000fffffffe  RBX: ffff889b77f6fc00  RCX:ffffffff81c99d88
    RDX: 0000000000000000  RSI: ffff896019ee08e8  RDI:ffff889b77f6fc00
    RBP: ffff898e35f15df0   R8: ffff896019ee08c8  R9:0000000000000000
    R10: 0000000000000400  R11: 0000000000000000  R12:ffff896019ee08c0
    R13: ffff889b77f6fe68  R14: ffffffff81c99d80  R15: ffffffffa022a1e0
    ORIG_RAX: ffffffffffffffff  CS: 0010 SS: 0018
 #8 [ffff898e35f15dc8] cma_ndev_work_handler at ffffffffa022a228 [rdma_cm]
 #9 [ffff898e35f15df8] process_one_work at ffffffff8108a7c6
 #10 [ffff898e35f15e58] worker_thread at ffffffff8108bda0
 #11 [ffff898e35f15ee8] kthread at ffffffff81090fe6

PID: 45659  TASK: ffff880d313d2500  CPU: 31  COMMAND: "oracle_45659_ap"
 #0 [ffff881024ccfc98] __schedule at ffffffff8150bac4
 #1 [ffff881024ccfd40] schedule at ffffffff8150c2cf
 #2 [ffff881024ccfd50] __mutex_lock_slowpath at ffffffff8150cee7
 #3 [ffff881024ccfdc0] mutex_lock at ffffffff8150cdeb
 #4 [ffff881024ccfde0] rdma_destroy_id at ffffffffa022a027 [rdma_cm]
 #5 [ffff881024ccfe10] rds_ib_laddr_check at ffffffffa0357857 [rds_rdma]
 #6 [ffff881024ccfe50] rds_trans_get_preferred at ffffffffa0324c2a [rds]
 #7 [ffff881024ccfe80] rds_bind at ffffffffa031d690 [rds]
 #8 [ffff881024ccfeb0] sys_bind at ffffffff8142a670

PID: 45659                          PID: 47039
rds_ib_laddr_check
  /* create id_priv with a null event_handler */
  rdma_create_id
  rdma_bind_addr
    cma_acquire_dev
      /* add id_priv to cma_dev->id_list */
      cma_attach_to_dev
                                    cma_ndev_work_handler
                                      /* event_hanlder is null */
                                      id_priv->id.event_handler

Signed-off-by: Guanglei Li <guanglei.li@oracle.com>
Signed-off-by: Honglei Wang <honglei.wang@oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Yanjun Zhu <yanjun.zhu@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request May 16, 2018
syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 ev3dev#1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 ev3dev#18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 ev3dev#18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 #32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
dlech pushed a commit to dlech/ev3dev-kernel that referenced this pull request May 16, 2018
Currently; we're grabbing all of the modesetting locks before adding MST
connectors to fbdev. This isn't actually necessary, and causes a
deadlock as well:

======================================================
WARNING: possible circular locking dependency detected
4.17.0-rc3Lyude-Test+ ev3dev#1 Tainted: G           O
------------------------------------------------------
kworker/1:0/18 is trying to acquire lock:
00000000c832f62d (&helper->lock){+.+.}, at: drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]

but task is already holding lock:
00000000942e28e2 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8e/0x1c0 [drm]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> ev3dev#3 (crtc_ww_class_mutex){+.+.}:
       ww_mutex_lock+0x43/0x80
       drm_modeset_lock+0x71/0x130 [drm]
       drm_helper_probe_single_connector_modes+0x7d/0x6b0 [drm_kms_helper]
       drm_setup_crtcs+0x15e/0xc90 [drm_kms_helper]
       __drm_fb_helper_initial_config_and_unlock+0x29/0x480 [drm_kms_helper]
       nouveau_fbcon_init+0x138/0x1a0 [nouveau]
       nouveau_drm_load+0x173/0x7e0 [nouveau]
       drm_dev_register+0x134/0x1c0 [drm]
       drm_get_pci_dev+0x8e/0x160 [drm]
       nouveau_drm_probe+0x1a9/0x230 [nouveau]
       pci_device_probe+0xcd/0x150
       driver_probe_device+0x30b/0x480
       __driver_attach+0xbc/0xe0
       bus_for_each_dev+0x67/0x90
       bus_add_driver+0x164/0x260
       driver_register+0x57/0xc0
       do_one_initcall+0x4d/0x323
       do_init_module+0x5b/0x1f8
       load_module+0x20e5/0x2ac0
       __do_sys_finit_module+0xb7/0xd0
       do_syscall_64+0x60/0x1b0
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> ev3dev#2 (crtc_ww_class_acquire){+.+.}:
       drm_helper_probe_single_connector_modes+0x58/0x6b0 [drm_kms_helper]
       drm_setup_crtcs+0x15e/0xc90 [drm_kms_helper]
       __drm_fb_helper_initial_config_and_unlock+0x29/0x480 [drm_kms_helper]
       nouveau_fbcon_init+0x138/0x1a0 [nouveau]
       nouveau_drm_load+0x173/0x7e0 [nouveau]
       drm_dev_register+0x134/0x1c0 [drm]
       drm_get_pci_dev+0x8e/0x160 [drm]
       nouveau_drm_probe+0x1a9/0x230 [nouveau]
       pci_device_probe+0xcd/0x150
       driver_probe_device+0x30b/0x480
       __driver_attach+0xbc/0xe0
       bus_for_each_dev+0x67/0x90
       bus_add_driver+0x164/0x260
       driver_register+0x57/0xc0
       do_one_initcall+0x4d/0x323
       do_init_module+0x5b/0x1f8
       load_module+0x20e5/0x2ac0
       __do_sys_finit_module+0xb7/0xd0
       do_syscall_64+0x60/0x1b0
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> ev3dev#1 (&dev->mode_config.mutex){+.+.}:
       drm_setup_crtcs+0x10c/0xc90 [drm_kms_helper]
       __drm_fb_helper_initial_config_and_unlock+0x29/0x480 [drm_kms_helper]
       nouveau_fbcon_init+0x138/0x1a0 [nouveau]
       nouveau_drm_load+0x173/0x7e0 [nouveau]
       drm_dev_register+0x134/0x1c0 [drm]
       drm_get_pci_dev+0x8e/0x160 [drm]
       nouveau_drm_probe+0x1a9/0x230 [nouveau]
       pci_device_probe+0xcd/0x150
       driver_probe_device+0x30b/0x480
       __driver_attach+0xbc/0xe0
       bus_for_each_dev+0x67/0x90
       bus_add_driver+0x164/0x260
       driver_register+0x57/0xc0
       do_one_initcall+0x4d/0x323
       do_init_module+0x5b/0x1f8
       load_module+0x20e5/0x2ac0
       __do_sys_finit_module+0xb7/0xd0
       do_syscall_64+0x60/0x1b0
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 (&helper->lock){+.+.}:
       __mutex_lock+0x70/0x9d0
       drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]
       nv50_mstm_register_connector+0x2c/0x50 [nouveau]
       drm_dp_add_port+0x2f5/0x420 [drm_kms_helper]
       drm_dp_send_link_address+0x155/0x1e0 [drm_kms_helper]
       drm_dp_add_port+0x33f/0x420 [drm_kms_helper]
       drm_dp_send_link_address+0x155/0x1e0 [drm_kms_helper]
       drm_dp_check_and_send_link_address+0x87/0xd0 [drm_kms_helper]
       drm_dp_mst_link_probe_work+0x4d/0x80 [drm_kms_helper]
       process_one_work+0x20d/0x650
       worker_thread+0x3a/0x390
       kthread+0x11e/0x140
       ret_from_fork+0x3a/0x50

other info that might help us debug this:
Chain exists of:
  &helper->lock --> crtc_ww_class_acquire --> crtc_ww_class_mutex
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(crtc_ww_class_mutex);
                               lock(crtc_ww_class_acquire);
                               lock(crtc_ww_class_mutex);
  lock(&helper->lock);

 *** DEADLOCK ***
5 locks held by kworker/1:0/18:
 #0: 000000004a05cd50 ((wq_completion)"events_long"){+.+.}, at: process_one_work+0x187/0x650
 ev3dev#1: 00000000601c11d1 ((work_completion)(&mgr->work)){+.+.}, at: process_one_work+0x187/0x650
 ev3dev#2: 00000000586ca0df (&dev->mode_config.mutex){+.+.}, at: drm_modeset_lock_all+0x3a/0x1b0 [drm]
 ev3dev#3: 00000000d3ca0ffa (crtc_ww_class_acquire){+.+.}, at: drm_modeset_lock_all+0x44/0x1b0 [drm]
 ev3dev#4: 00000000942e28e2 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8e/0x1c0 [drm]

stack backtrace:
CPU: 1 PID: 18 Comm: kworker/1:0 Tainted: G           O      4.17.0-rc3Lyude-Test+ ev3dev#1
Hardware name: Gateway FX6840/FX6840, BIOS P01-A3         05/17/2010
Workqueue: events_long drm_dp_mst_link_probe_work [drm_kms_helper]
Call Trace:
 dump_stack+0x85/0xcb
 print_circular_bug.isra.38+0x1ce/0x1db
 __lock_acquire+0x128f/0x1350
 ? lock_acquire+0x9f/0x200
 ? lock_acquire+0x9f/0x200
 ? __ww_mutex_lock.constprop.13+0x8f/0x1000
 lock_acquire+0x9f/0x200
 ? drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]
 ? drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]
 __mutex_lock+0x70/0x9d0
 ? drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]
 ? ww_mutex_lock+0x43/0x80
 ? _cond_resched+0x15/0x30
 ? ww_mutex_lock+0x43/0x80
 ? drm_modeset_lock+0xb2/0x130 [drm]
 ? drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]
 drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]
 nv50_mstm_register_connector+0x2c/0x50 [nouveau]
 drm_dp_add_port+0x2f5/0x420 [drm_kms_helper]
 ? mark_held_locks+0x50/0x80
 ? kfree+0xcf/0x2a0
 ? drm_dp_check_mstb_guid+0xd6/0x120 [drm_kms_helper]
 ? trace_hardirqs_on_caller+0xed/0x180
 ? drm_dp_check_mstb_guid+0xd6/0x120 [drm_kms_helper]
 drm_dp_send_link_address+0x155/0x1e0 [drm_kms_helper]
 drm_dp_add_port+0x33f/0x420 [drm_kms_helper]
 ? nouveau_connector_aux_xfer+0x7c/0xb0 [nouveau]
 ? find_held_lock+0x2d/0x90
 ? drm_dp_dpcd_access+0xd9/0xf0 [drm_kms_helper]
 ? __mutex_unlock_slowpath+0x3b/0x280
 ? drm_dp_dpcd_access+0xd9/0xf0 [drm_kms_helper]
 drm_dp_send_link_address+0x155/0x1e0 [drm_kms_helper]
 drm_dp_check_and_send_link_address+0x87/0xd0 [drm_kms_helper]
 drm_dp_mst_link_probe_work+0x4d/0x80 [drm_kms_helper]
 process_one_work+0x20d/0x650
 worker_thread+0x3a/0x390
 ? process_one_work+0x650/0x650
 kthread+0x11e/0x140
 ? kthread_create_worker_on_cpu+0x50/0x50
 ret_from_fork+0x3a/0x50

Taking example from i915, the only time we need to hold any modesetting
locks is when changing the port on the mstc, and in that case we only
need to hold the connection mutex.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: stable@vger.kernel.org

Signed-off-by: Lyude Paul <lyude@redhat.com>

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
dlech pushed a commit that referenced this pull request Jun 13, 2018
commit 85bd0ba upstream.

Although we've implemented PSCI 0.1, 0.2 and 1.0, we expose either 0.1
or 1.0 to a guest, defaulting to the latest version of the PSCI
implementation that is compatible with the requested version. This is
no different from doing a firmware upgrade on KVM.

But in order to give a chance to hypothetical badly implemented guests
that would have a fit by discovering something other than PSCI 0.2,
let's provide a new API that allows userspace to pick one particular
version of the API.

This is implemented as a new class of "firmware" registers, where
we expose the PSCI version. This allows the PSCI version to be
save/restored as part of a guest migration, and also set to
any supported version if the guest requires it.

Cc: stable@vger.kernel.org #4.16
Reviewed-by: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Jun 13, 2018
commit 352672d upstream.

Currently; we're grabbing all of the modesetting locks before adding MST
connectors to fbdev. This isn't actually necessary, and causes a
deadlock as well:

======================================================
WARNING: possible circular locking dependency detected
4.17.0-rc3Lyude-Test+ #1 Tainted: G           O
------------------------------------------------------
kworker/1:0/18 is trying to acquire lock:
00000000c832f62d (&helper->lock){+.+.}, at: drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]

but task is already holding lock:
00000000942e28e2 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8e/0x1c0 [drm]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (crtc_ww_class_mutex){+.+.}:
       ww_mutex_lock+0x43/0x80
       drm_modeset_lock+0x71/0x130 [drm]
       drm_helper_probe_single_connector_modes+0x7d/0x6b0 [drm_kms_helper]
       drm_setup_crtcs+0x15e/0xc90 [drm_kms_helper]
       __drm_fb_helper_initial_config_and_unlock+0x29/0x480 [drm_kms_helper]
       nouveau_fbcon_init+0x138/0x1a0 [nouveau]
       nouveau_drm_load+0x173/0x7e0 [nouveau]
       drm_dev_register+0x134/0x1c0 [drm]
       drm_get_pci_dev+0x8e/0x160 [drm]
       nouveau_drm_probe+0x1a9/0x230 [nouveau]
       pci_device_probe+0xcd/0x150
       driver_probe_device+0x30b/0x480
       __driver_attach+0xbc/0xe0
       bus_for_each_dev+0x67/0x90
       bus_add_driver+0x164/0x260
       driver_register+0x57/0xc0
       do_one_initcall+0x4d/0x323
       do_init_module+0x5b/0x1f8
       load_module+0x20e5/0x2ac0
       __do_sys_finit_module+0xb7/0xd0
       do_syscall_64+0x60/0x1b0
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #2 (crtc_ww_class_acquire){+.+.}:
       drm_helper_probe_single_connector_modes+0x58/0x6b0 [drm_kms_helper]
       drm_setup_crtcs+0x15e/0xc90 [drm_kms_helper]
       __drm_fb_helper_initial_config_and_unlock+0x29/0x480 [drm_kms_helper]
       nouveau_fbcon_init+0x138/0x1a0 [nouveau]
       nouveau_drm_load+0x173/0x7e0 [nouveau]
       drm_dev_register+0x134/0x1c0 [drm]
       drm_get_pci_dev+0x8e/0x160 [drm]
       nouveau_drm_probe+0x1a9/0x230 [nouveau]
       pci_device_probe+0xcd/0x150
       driver_probe_device+0x30b/0x480
       __driver_attach+0xbc/0xe0
       bus_for_each_dev+0x67/0x90
       bus_add_driver+0x164/0x260
       driver_register+0x57/0xc0
       do_one_initcall+0x4d/0x323
       do_init_module+0x5b/0x1f8
       load_module+0x20e5/0x2ac0
       __do_sys_finit_module+0xb7/0xd0
       do_syscall_64+0x60/0x1b0
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #1 (&dev->mode_config.mutex){+.+.}:
       drm_setup_crtcs+0x10c/0xc90 [drm_kms_helper]
       __drm_fb_helper_initial_config_and_unlock+0x29/0x480 [drm_kms_helper]
       nouveau_fbcon_init+0x138/0x1a0 [nouveau]
       nouveau_drm_load+0x173/0x7e0 [nouveau]
       drm_dev_register+0x134/0x1c0 [drm]
       drm_get_pci_dev+0x8e/0x160 [drm]
       nouveau_drm_probe+0x1a9/0x230 [nouveau]
       pci_device_probe+0xcd/0x150
       driver_probe_device+0x30b/0x480
       __driver_attach+0xbc/0xe0
       bus_for_each_dev+0x67/0x90
       bus_add_driver+0x164/0x260
       driver_register+0x57/0xc0
       do_one_initcall+0x4d/0x323
       do_init_module+0x5b/0x1f8
       load_module+0x20e5/0x2ac0
       __do_sys_finit_module+0xb7/0xd0
       do_syscall_64+0x60/0x1b0
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 (&helper->lock){+.+.}:
       __mutex_lock+0x70/0x9d0
       drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]
       nv50_mstm_register_connector+0x2c/0x50 [nouveau]
       drm_dp_add_port+0x2f5/0x420 [drm_kms_helper]
       drm_dp_send_link_address+0x155/0x1e0 [drm_kms_helper]
       drm_dp_add_port+0x33f/0x420 [drm_kms_helper]
       drm_dp_send_link_address+0x155/0x1e0 [drm_kms_helper]
       drm_dp_check_and_send_link_address+0x87/0xd0 [drm_kms_helper]
       drm_dp_mst_link_probe_work+0x4d/0x80 [drm_kms_helper]
       process_one_work+0x20d/0x650
       worker_thread+0x3a/0x390
       kthread+0x11e/0x140
       ret_from_fork+0x3a/0x50

other info that might help us debug this:
Chain exists of:
  &helper->lock --> crtc_ww_class_acquire --> crtc_ww_class_mutex
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(crtc_ww_class_mutex);
                               lock(crtc_ww_class_acquire);
                               lock(crtc_ww_class_mutex);
  lock(&helper->lock);

 *** DEADLOCK ***
5 locks held by kworker/1:0/18:
 #0: 000000004a05cd50 ((wq_completion)"events_long"){+.+.}, at: process_one_work+0x187/0x650
 #1: 00000000601c11d1 ((work_completion)(&mgr->work)){+.+.}, at: process_one_work+0x187/0x650
 #2: 00000000586ca0df (&dev->mode_config.mutex){+.+.}, at: drm_modeset_lock_all+0x3a/0x1b0 [drm]
 #3: 00000000d3ca0ffa (crtc_ww_class_acquire){+.+.}, at: drm_modeset_lock_all+0x44/0x1b0 [drm]
 #4: 00000000942e28e2 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8e/0x1c0 [drm]

stack backtrace:
CPU: 1 PID: 18 Comm: kworker/1:0 Tainted: G           O      4.17.0-rc3Lyude-Test+ #1
Hardware name: Gateway FX6840/FX6840, BIOS P01-A3         05/17/2010
Workqueue: events_long drm_dp_mst_link_probe_work [drm_kms_helper]
Call Trace:
 dump_stack+0x85/0xcb
 print_circular_bug.isra.38+0x1ce/0x1db
 __lock_acquire+0x128f/0x1350
 ? lock_acquire+0x9f/0x200
 ? lock_acquire+0x9f/0x200
 ? __ww_mutex_lock.constprop.13+0x8f/0x1000
 lock_acquire+0x9f/0x200
 ? drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]
 ? drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]
 __mutex_lock+0x70/0x9d0
 ? drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]
 ? ww_mutex_lock+0x43/0x80
 ? _cond_resched+0x15/0x30
 ? ww_mutex_lock+0x43/0x80
 ? drm_modeset_lock+0xb2/0x130 [drm]
 ? drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]
 drm_fb_helper_add_one_connector+0x2a/0x60 [drm_kms_helper]
 nv50_mstm_register_connector+0x2c/0x50 [nouveau]
 drm_dp_add_port+0x2f5/0x420 [drm_kms_helper]
 ? mark_held_locks+0x50/0x80
 ? kfree+0xcf/0x2a0
 ? drm_dp_check_mstb_guid+0xd6/0x120 [drm_kms_helper]
 ? trace_hardirqs_on_caller+0xed/0x180
 ? drm_dp_check_mstb_guid+0xd6/0x120 [drm_kms_helper]
 drm_dp_send_link_address+0x155/0x1e0 [drm_kms_helper]
 drm_dp_add_port+0x33f/0x420 [drm_kms_helper]
 ? nouveau_connector_aux_xfer+0x7c/0xb0 [nouveau]
 ? find_held_lock+0x2d/0x90
 ? drm_dp_dpcd_access+0xd9/0xf0 [drm_kms_helper]
 ? __mutex_unlock_slowpath+0x3b/0x280
 ? drm_dp_dpcd_access+0xd9/0xf0 [drm_kms_helper]
 drm_dp_send_link_address+0x155/0x1e0 [drm_kms_helper]
 drm_dp_check_and_send_link_address+0x87/0xd0 [drm_kms_helper]
 drm_dp_mst_link_probe_work+0x4d/0x80 [drm_kms_helper]
 process_one_work+0x20d/0x650
 worker_thread+0x3a/0x390
 ? process_one_work+0x650/0x650
 kthread+0x11e/0x140
 ? kthread_create_worker_on_cpu+0x50/0x50
 ret_from_fork+0x3a/0x50

Taking example from i915, the only time we need to hold any modesetting
locks is when changing the port on the mstc, and in that case we only
need to hold the connection mutex.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Jun 13, 2018
[ Upstream commit af50e4b ]

syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 #32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Jun 13, 2018
[ Upstream commit b86b8eb ]

ACM driver may accept data to transmit while system is not fully
resumed. In this case ACM driver buffers data and prepare URBs
on usb anchor list.
There is a little chance that two tasks put a char and initiate
acm_tty_flush_chars(). In such a case, driver will put one URB
twice on usb anchor list.
This patch also reset length of data before resue of a buffer.
This not only prevent sending rubbish, but also lower risc of race.

Without this patch we hit following kernel panic in one of our
stabilty/stress tests.

[   46.884442] *list_add double add*: new=ffff9b2ab7289330, prev=ffff9b2ab7289330, next=ffff9b2ab81e28e0.
[   46.884476] Modules linked in: hci_uart btbcm bluetooth rfkill_gpio igb_avb(O) cfg80211 snd_soc_sst_bxt_tdf8532 snd_soc_skl snd_soc_skl_ipc snd_soc_sst_ipc snd_soc_sst_dsp snd_soc_sst_acpi snd_soc_sst_match snd_hda_ext_core snd_hda_core trusty_timer trusty_wall trusty_log trusty_virtio trusty_ipc trusty_mem trusty_irq trusty virtio_ring virtio intel_ipu4_mmu_bxtB0 lib2600_mod_bxtB0 intel_ipu4_isys_mod_bxtB0 lib2600psys_mod_bxtB0 intel_ipu4_psys_mod_bxtB0 intel_ipu4_mod_bxtB0 intel_ipu4_wrapper_bxtB0 intel_ipu4_acpi videobuf2_dma_contig as3638 dw9714 lm3643 crlmodule smiapp smiapp_pll
[   46.884480] CPU: 1 PID: 33 Comm: kworker/u8:1 Tainted: G     U  W  O    4.9.56-quilt-2e5dc0ac-g618ed69ced6e-dirty #4
[   46.884489] Workqueue: events_unbound flush_to_ldisc
[   46.884494]  ffffb98ac012bb08 ffffffffad3e82e5 ffffb98ac012bb58 0000000000000000
[   46.884497]  ffffb98ac012bb48 ffffffffad0a23d1 00000024ad6374dd ffff9b2ab7289330
[   46.884500]  ffff9b2ab81e28e0 ffff9b2ab7289330 0000000000000002 0000000000000000
[   46.884501] Call Trace:
[   46.884507]  [<ffffffffad3e82e5>] dump_stack+0x67/0x92
[   46.884511]  [<ffffffffad0a23d1>] __warn+0xd1/0xf0
[   46.884513]  [<ffffffffad0a244f>] warn_slowpath_fmt+0x5f/0x80
[   46.884516]  [<ffffffffad407443>] __list_add+0xb3/0xc0
[   46.884521]  [<ffffffffad71133c>] *usb_anchor_urb*+0x4c/0xa0
[   46.884524]  [<ffffffffad782c6f>] *acm_tty_flush_chars*+0x8f/0xb0
[   46.884527]  [<ffffffffad782cd1>] *acm_tty_put_char*+0x41/0x100
[   46.884530]  [<ffffffffad4ced34>] tty_put_char+0x24/0x40
[   46.884533]  [<ffffffffad4d3bf5>] do_output_char+0xa5/0x200
[   46.884535]  [<ffffffffad4d3e98>] __process_echoes+0x148/0x290
[   46.884538]  [<ffffffffad4d654c>] n_tty_receive_buf_common+0x57c/0xb00
[   46.884541]  [<ffffffffad4d6ae4>] n_tty_receive_buf2+0x14/0x20
[   46.884543]  [<ffffffffad4d9662>] tty_ldisc_receive_buf+0x22/0x50
[   46.884545]  [<ffffffffad4d9c05>] flush_to_ldisc+0xc5/0xe0
[   46.884549]  [<ffffffffad0bcfe8>] process_one_work+0x148/0x440
[   46.884551]  [<ffffffffad0bdc19>] worker_thread+0x69/0x4a0
[   46.884554]  [<ffffffffad0bdbb0>] ? max_active_store+0x80/0x80
[   46.884556]  [<ffffffffad0c2e10>] kthread+0x110/0x130
[   46.884559]  [<ffffffffad0c2d00>] ? kthread_park+0x60/0x60
[   46.884563]  [<ffffffffadad9917>] ret_from_fork+0x27/0x40
[   46.884566] ---[ end trace 3bd599058b8a9eb3 ]---

Signed-off-by: Dominik Bozek <dominikx.bozek@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Jun 13, 2018
[ Upstream commit ad46e48 ]

Currently we can crash perf record when running in pipe mode, like:

  $ perf record ls | perf report
  # To display the perf.data header info, please use --header/--header-only options.
  #
  perf: Segmentation fault
  Error:
  The - file has no samples!

The callstack of the crash is:

    0x0000000000515242 in perf_event__synthesize_event_update_name
  3513            ev = event_update_event__new(len + 1, PERF_EVENT_UPDATE__NAME, evsel->id[0]);
  (gdb) bt
  #0  0x0000000000515242 in perf_event__synthesize_event_update_name
  #1  0x00000000005158a4 in perf_event__synthesize_extra_attr
  #2  0x0000000000443347 in record__synthesize
  #3  0x00000000004438e3 in __cmd_record
  #4  0x000000000044514e in cmd_record
  #5  0x00000000004cbc95 in run_builtin
  #6  0x00000000004cbf02 in handle_internal_command
  #7  0x00000000004cc054 in run_argv
  #8  0x00000000004cc422 in main

The reason of the crash is that the evsel does not have ids array
allocated and the pipe's synthesize code tries to access it.

We don't force evsel ids allocation when we have single event, because
it's not needed. However we need it when we are in pipe mode even for
single event as a key for evsel update event.

Fixing this by forcing evsel ids allocation event for single event, when
we are in pipe mode.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180302161354.30192-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Jun 13, 2018
[ Upstream commit f61e643 ]

As of commit 205e1b7 ("dma-mapping: warn when there is no
coherent_dma_mask") the Freescale FEC driver is issuing the following
warning on driver initialization on ColdFire systems:

WARNING: CPU: 0 PID: 1 at ./include/linux/dma-mapping.h:516 0x40159e20
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.16.0-rc7-dirty #4
Stack from 41833dd8:
        41833dd8 40259c53 40025534 40279e26 00000003 00000000 4004e514 41827000
        400255de 40244e42 00000204 40159e20 00000009 00000000 00000000 4024531d
        40159e20 40244e42 00000204 00000000 00000000 00000000 00000007 00000000
        00000000 40279e26 4028d040 40226576 4003ae88 40279e26 418273f6 41833ef8
        7fffffff 418273f2 41867028 4003c9a2 4180ac6c 00000004 41833f8c 4013e71c
        40279e1c 40279e26 40226c16 4013ced2 40279e26 40279e58 4028d040 00000000
Call Trace:
        [<40025534>] 0x40025534
 [<4004e514>] 0x4004e514
 [<400255de>] 0x400255de
 [<40159e20>] 0x40159e20
 [<40159e20>] 0x40159e20

It is not fatal, the driver and the system continue to function normally.

As per the warning the coherent_dma_mask is not set on this device.
There is nothing special about the DMA memory coherency on this hardware
so we can just set the mask to 32bits in the platform data for the FEC
ethernet devices.

Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Jun 13, 2018
[ Upstream commit fca3234 ]

Executing command 'perf stat -T -- ls' dumps core on x86 and s390.

Here is the call back chain (done on x86):

 # gdb ./perf
 ....
 (gdb) r stat -T -- ls
...
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
(gdb) where
 #0  0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
 #1  0x00007ffff56ae484 in asprintf () from /lib64/libc.so.6
 #2  0x00000000004f1982 in __parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930, auto_merge_stats=false) at util/parse-events.c:1233
 #3  0x00000000004f1c8e in parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930) at util/parse-events.c:1288
 #4  0x0000000000537ce3 in parse_events_parse (_parse_state=0x7fffffffd580,
    scanner=0xbf4210) at util/parse-events.y:234
 #5  0x00000000004f2c7a in parse_events__scanner (str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}",
    parse_state=0x7fffffffd580, start_token=258) at util/parse-events.c:1673
 #6  0x00000000004f2e23 in parse_events (evlist=0xbe9990, str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}", err=0x0)
    at util/parse-events.c:1713
 #7  0x000000000044e137 in add_default_attributes () at builtin-stat.c:2281
 #8  0x000000000044f7b5 in cmd_stat (argc=1, argv=0x7fffffffe3b0) at
    builtin-stat.c:2828
 #9  0x00000000004c8b0f in run_builtin (p=0xab01a0 <commands+288>, argc=4,
    argv=0x7fffffffe3b0) at perf.c:297
 #10 0x00000000004c8d7c in handle_internal_command (argc=4,
    argv=0x7fffffffe3b0) at perf.c:349
 #11 0x00000000004c8ece in run_argv (argcp=0x7fffffffe20c,
   argv=0x7fffffffe200) at perf.c:393
 #12 0x00000000004c929c in main (argc=4, argv=0x7fffffffe3b0) at perf.c:537
(gdb)

It turns out that a NULL pointer is referenced. Here are the
function calls:

  ...
  cmd_stat()
  +---> add_default_attributes()
	+---> parse_events(evsel_list, transaction_attrs, NULL);
	             3rd parameter set to NULL

Function parse_events(xx, xx, struct parse_events_error *err) dives
into a bison generated scanner and creates
parser state information for it first:

   struct parse_events_state parse_state = {
                .list   = LIST_HEAD_INIT(parse_state.list),
                .idx    = evlist->nr_entries,
                .error  = err,   <--- NULL POINTER !!!
                .evlist = evlist,
        };

Now various functions inside the bison scanner are called to end up in
__parse_events_add_pmu(struct parse_events_state *parse_state, ..) with
first parameter being a pointer to above structure definition.

Now the PMU event name is not found (because being executed in a VM) and
this function tries to create an error message with

   asprintf(&parse_state->error.str, ....)

which references a NULL pointer and dumps core.

Fix this by providing a pointer to the necessary error information
instead of NULL. Technically only the else part is needed to avoid the
core dump, just lets be safe...

Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20180308145735.64717-1-tmricht@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Jun 13, 2018
[ Upstream commit 2bbea6e ]

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 #8 [ffff880078447da8] mount_bdev at ffffffff81202570
 #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
#10 [ffff880078447e28] mount_fs at ffffffff81202d09
#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
#12 [ffff880078447ea8] do_mount at ffffffff81220fee
#13 [ffff880078447f28] sys_mount at ffffffff812218d6
#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 #1 [ffff880078417900] schedule at ffffffff8168dc59
 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 #4 [ffff8800784179d0] down_read at ffffffff8168cde0
 #5 [ffff8800784179e8] get_super at ffffffff81201cc7
 #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
#16 [ffff880078417d00] do_last at ffffffff8120d53d
#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
#20 [ffff880078417f70] sys_open at ffffffff811fde4e
#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Jul 26, 2018
commit 2546da9 upstream.

The RX SGL in processing is already registered with the RX SGL tracking
list to support proper cleanup. The cleanup code path uses the
sg_num_bytes variable which must therefore be always initialized, even
in the error code path.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Reported-by: syzbot+9c251bdd09f83b92ba95@syzkaller.appspotmail.com
#syz test: https://github.com/google/kmsan.git master
CC: <stable@vger.kernel.org> #4.14
Fixes: e870456 ("crypto: algif_skcipher - overhaul memory management")
Fixes: d887c52 ("crypto: algif_aead - overhaul memory management")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Jul 26, 2018
commit 3f6e698 upstream.

Since commit 1bb8866 ("mtd: nand: denali: handle timing parameters
by setup_data_interface()"), denali_dt.c gets the clock rate from the
clock driver.  The driver expects the frequency of the bus interface
clock, whereas the clock driver of SOCFPGA provides the core clock.
Thus, the setup_data_interface() hook calculates timing parameters
based on a wrong frequency.

To make it work without relying on the clock driver, hard-code the clock
frequency, 200MHz.  This is fine for existing DT of UniPhier, and also
fixes the issue of SOCFPGA because both platforms use 200 MHz for the
bus interface clock.

Fixes: 1bb8866 ("mtd: nand: denali: handle timing parameters by setup_data_interface()")
Cc: linux-stable <stable@vger.kernel.org> #4.14+
Reported-by: Philipp Rosenberger <p.rosenberger@linutronix.de>
Suggested-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Jul 26, 2018
commit af1fc5b upstream.

This manifsted as strace segfaulting on HSDK because gcc was targetting
the accumulator registers as GPRs, which kernek was not saving/restoring
by default.

Cc: stable@vger.kernel.org   #4.14+
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Aug 6, 2018
[ Upstream commit 4f4616c ]

Similar to what we do when we remove a PCI function, set the
QEDF_UNLOADING flag to prevent any requests from being queued while a
vport is being deleted.  This prevents any requests from getting stuck
in limbo when the vport is unloaded or deleted.

Fixes the crash:

PID: 106676  TASK: ffff9a436aa90000  CPU: 12  COMMAND: "multipathd"
 #0 [ffff9a43567d3550] machine_kexec+522 at ffffffffaca60b2a
 #1 [ffff9a43567d35b0] __crash_kexec+114 at ffffffffacb13512
 #2 [ffff9a43567d3680] crash_kexec+48 at ffffffffacb13600
 #3 [ffff9a43567d3698] oops_end+168 at ffffffffad117768
 #4 [ffff9a43567d36c0] no_context+645 at ffffffffad106f52
 #5 [ffff9a43567d3710] __bad_area_nosemaphore+116 at ffffffffad106fe9
 #6 [ffff9a43567d3760] bad_area+70 at ffffffffad107379
 #7 [ffff9a43567d3788] __do_page_fault+1247 at ffffffffad11a8cf
 #8 [ffff9a43567d37f0] do_page_fault+53 at ffffffffad11a915
 #9 [ffff9a43567d3820] page_fault+40 at ffffffffad116768
    [exception RIP: qedf_init_task+61]
    RIP: ffffffffc0e13c2d  RSP: ffff9a43567d38d0  RFLAGS: 00010046
    RAX: 0000000000000000  RBX: ffffbe920472c738  RCX: ffff9a434fa0e3e8
    RDX: ffff9a434f695280  RSI: ffffbe920472c738  RDI: ffff9a43aa359c80
    RBP: ffff9a43567d3950   R8: 0000000000000c15   R9: ffff9a3fb09b9880
    R10: ffff9a434fa0e3e8  R11: ffff9a43567d35ce  R12: 0000000000000000
    R13: ffff9a434f695280  R14: ffff9a43aa359c80  R15: ffff9a3fb9e005c0
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018

Signed-off-by: Chad Dupuis <chad.dupuis@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Aug 6, 2018
commit e8d4bfe upstream.

When executing filesystem sync or umount on overlayfs,
dirty data does not get synced as expected on upper filesystem.
This patch fixes sync filesystem method to keep data consistency
for overlayfs.

Signed-off-by: Chengguang Xu <cgxu@mykernel.net>
Fixes: e593b2b ("ovl: properly implement sync_filesystem()")
Cc: <stable@vger.kernel.org> #4.11
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Aug 6, 2018
commit 89da619 upstream.

Kernel panic when with high memory pressure, calltrace looks like,

PID: 21439 TASK: ffff881be3afedd0 CPU: 16 COMMAND: "java"
 #0 [ffff881ec7ed7630] machine_kexec at ffffffff81059beb
 #1 [ffff881ec7ed7690] __crash_kexec at ffffffff81105942
 #2 [ffff881ec7ed7760] crash_kexec at ffffffff81105a30
 #3 [ffff881ec7ed7778] oops_end at ffffffff816902c8
 #4 [ffff881ec7ed77a0] no_context at ffffffff8167ff46
 #5 [ffff881ec7ed77f0] __bad_area_nosemaphore at ffffffff8167ffdc
 #6 [ffff881ec7ed7838] __node_set at ffffffff81680300
 #7 [ffff881ec7ed7860] __do_page_fault at ffffffff8169320f
 #8 [ffff881ec7ed78c0] do_page_fault at ffffffff816932b5
 #9 [ffff881ec7ed78f0] page_fault at ffffffff8168f4c8
    [exception RIP: _raw_spin_lock_irqsave+47]
    RIP: ffffffff8168edef RSP: ffff881ec7ed79a8 RFLAGS: 00010046
    RAX: 0000000000000246 RBX: ffffea0019740d00 RCX: ffff881ec7ed7fd8
    RDX: 0000000000020000 RSI: 0000000000000016 RDI: 0000000000000008
    RBP: ffff881ec7ed79a8 R8: 0000000000000246 R9: 000000000001a098
    R10: ffff88107ffda000 R11: 0000000000000000 R12: 0000000000000000
    R13: 0000000000000008 R14: ffff881ec7ed7a80 R15: ffff881be3afedd0
    ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018

It happens in the pagefault and results in double pagefault
during compacting pages when memory allocation fails.

Analysed the vmcore, the page leads to second pagefault is corrupted
with _mapcount=-256, but private=0.

It's caused by the race between migration and ballooning, and lock
missing in virtballoon_migratepage() of virtio_balloon driver.
This patch fix the bug.

Fixes: e225042 ("virtio_balloon: introduce migration primitives to balloon pages")
Cc: stable@vger.kernel.org
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Huang Chong <huang.chong@zte.com.cn>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dlech pushed a commit that referenced this pull request Sep 23, 2018
commit 147b27e upstream.

It may cause race by setting 'nvmeq' in nvme_init_request()
because .init_request is called inside switching io scheduler, which
may happen when the NVMe device is being resetted and its nvme queues
are being freed and created. We don't have any sync between the two
pathes.

This patch changes the nvmeq allocation to occur at probe time so
there is no way we can dereference it at init_request.

[   93.268391] kernel BUG at drivers/nvme/host/pci.c:408!
[   93.274146] invalid opcode: 0000 [#1] SMP
[   93.278618] Modules linked in: nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss
nfsv4 dns_resolver nfs lockd grace fscache sunrpc ipmi_ssif vfat fat
intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel
kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel iTCO_wdt
intel_cstate ipmi_si iTCO_vendor_support intel_uncore mxm_wmi mei_me
ipmi_devintf intel_rapl_perf pcspkr sg ipmi_msghandler lpc_ich dcdbas mei
shpchp acpi_power_meter wmi dm_multipath ip_tables xfs libcrc32c sd_mod
mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt
fb_sys_fops ttm drm ahci libahci nvme libata crc32c_intel nvme_core tg3
megaraid_sas ptp i2c_core pps_core dm_mirror dm_region_hash dm_log dm_mod
[   93.349071] CPU: 5 PID: 1842 Comm: sh Not tainted 4.15.0-rc2.ming+ #4
[   93.356256] Hardware name: Dell Inc. PowerEdge R730xd/072T6D, BIOS 2.5.5 08/16/2017
[   93.364801] task: 00000000fb8abf2a task.stack: 0000000028bd82d1
[   93.371408] RIP: 0010:nvme_init_request+0x36/0x40 [nvme]
[   93.377333] RSP: 0018:ffffc90002537ca8 EFLAGS: 00010246
[   93.383161] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000008
[   93.391122] RDX: 0000000000000000 RSI: ffff880276ae0000 RDI: ffff88047bae9008
[   93.399084] RBP: ffff88047bae9008 R08: ffff88047bae9008 R09: 0000000009dabc00
[   93.407045] R10: 0000000000000004 R11: 000000000000299c R12: ffff880186bc1f00
[   93.415007] R13: ffff880276ae0000 R14: 0000000000000000 R15: 0000000000000071
[   93.422969] FS:  00007f33cf288740(0000) GS:ffff88047ba80000(0000) knlGS:0000000000000000
[   93.431996] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   93.438407] CR2: 00007f33cf28e000 CR3: 000000047e5bb006 CR4: 00000000001606e0
[   93.446368] Call Trace:
[   93.449103]  blk_mq_alloc_rqs+0x231/0x2a0
[   93.453579]  blk_mq_sched_alloc_tags.isra.8+0x42/0x80
[   93.459214]  blk_mq_init_sched+0x7e/0x140
[   93.463687]  elevator_switch+0x5a/0x1f0
[   93.467966]  ? elevator_get.isra.17+0x52/0xc0
[   93.472826]  elv_iosched_store+0xde/0x150
[   93.477299]  queue_attr_store+0x4e/0x90
[   93.481580]  kernfs_fop_write+0xfa/0x180
[   93.485958]  __vfs_write+0x33/0x170
[   93.489851]  ? __inode_security_revalidate+0x4c/0x60
[   93.495390]  ? selinux_file_permission+0xda/0x130
[   93.500641]  ? _cond_resched+0x15/0x30
[   93.504815]  vfs_write+0xad/0x1a0
[   93.508512]  SyS_write+0x52/0xc0
[   93.512113]  do_syscall_64+0x61/0x1a0
[   93.516199]  entry_SYSCALL64_slow_path+0x25/0x25
[   93.521351] RIP: 0033:0x7f33ce96aab0
[   93.525337] RSP: 002b:00007ffe57570238 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[   93.533785] RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f33ce96aab0
[   93.541746] RDX: 0000000000000006 RSI: 00007f33cf28e000 RDI: 0000000000000001
[   93.549707] RBP: 00007f33cf28e000 R08: 000000000000000a R09: 00007f33cf288740
[   93.557669] R10: 00007f33cf288740 R11: 0000000000000246 R12: 00007f33cec42400
[   93.565630] R13: 0000000000000006 R14: 0000000000000001 R15: 0000000000000000
[   93.573592] Code: 4c 8d 40 08 4c 39 c7 74 16 48 8b 00 48 8b 04 08 48 85 c0
74 16 48 89 86 78 01 00 00 31 c0 c3 8d 4a 01 48 63 c9 48 c1 e1 03 eb de <0f>
0b 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 85 f6 53 48 89
[   93.594676] RIP: nvme_init_request+0x36/0x40 [nvme] RSP: ffffc90002537ca8
[   93.602273] ---[ end trace 810dde3993e5f14e ]---

Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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