[Merge tag 'pci-v4.12-changes' of git] 857f864014: BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8

Greetings,

0day kernel testing robot got the below dmesg and the first bad commit is

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

commit 857f8640147c9fb43f20e43cbca6452710e1ca5d
Merge: 8f3207c7eab9d 3146c8f4de9b0
Author:     Linus Torvalds [off-list ref]
AuthorDate: Mon May 8 19:03:25 2017 -0700
Commit:     Linus Torvalds [off-list ref]
CommitDate: Mon May 8 19:03:25 2017 -0700

    Merge tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
    
    Pull PCI updates from Bjorn Helgaas:
    
     - add framework for supporting PCIe devices in Endpoint mode (Kishon
       Vijay Abraham I)
    
     - use non-postable PCI config space mappings when possible (Lorenzo
       Pieralisi)
    
     - clean up and unify mmap of PCI BARs (David Woodhouse)
    
     - export and unify Function Level Reset support (Christoph Hellwig)
    
     - avoid FLR for Intel 82579 NICs (Sasha Neftin)
    
     - add pci_request_irq() and pci_free_irq() helpers (Christoph Hellwig)
    
     - short-circuit config access failures for disconnected devices (Keith
       Busch)
    
     - remove D3 sleep delay when possible (Adrian Hunter)
    
     - freeze PME scan before suspending devices (Lukas Wunner)
    
     - stop disabling MSI/MSI-X in pci_device_shutdown() (Prarit Bhargava)
    
     - disable boot interrupt quirk for ASUS M2N-LR (Stefan Assmann)
    
     - add arch-specific alignment control to improve device passthrough by
       avoiding multiple BARs in a page (Yongji Xie)
    
     - add sysfs sriov_drivers_autoprobe to control VF driver binding
       (Bodong Wang)
    
     - allow slots below PCI-to-PCIe "reverse bridges" (Bjorn Helgaas)
    
     - fix crashes when unbinding host controllers that don't support
       removal (Brian Norris)
    
     - add driver for MicroSemi Switchtec management interface (Logan
       Gunthorpe)
    
     - add driver for Faraday Technology FTPCI100 host bridge (Linus
       Walleij)
    
     - add i.MX7D support (Andrey Smirnov)
    
     - use generic MSI support for Aardvark (Thomas Petazzoni)
    
     - make Rockchip driver modular (Brian Norris)
    
     - advertise 128-byte Read Completion Boundary support for Rockchip
       (Shawn Lin)
    
     - advertise PCI_EXP_LNKSTA_SLC for Rockchip root port (Shawn Lin)
    
     - convert atomic_t to refcount_t in HV driver (Elena Reshetova)
    
     - add CPU IRQ affinity in HV driver (K. Y. Srinivasan)
    
     - fix PCI bus removal in HV driver (Long Li)
    
     - add support for ThunderX2 DMA alias topology (Jayachandran C)
    
     - add ThunderX pass2.x 2nd node MCFG quirk (Tomasz Nowicki)
    
     - add ITE 8893 bridge DMA alias quirk (Jarod Wilson)
    
     - restrict Cavium ACS quirk only to CN81xx/CN83xx/CN88xx devices
       (Manish Jaggi)
    
    * tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (146 commits)
      PCI: Don't allow unbinding host controllers that aren't prepared
      ARM: DRA7: clockdomain: Change the CLKTRCTRL of CM_PCIE_CLKSTCTRL to SW_WKUP
      MAINTAINERS: Add PCI Endpoint maintainer
      Documentation: PCI: Add userguide for PCI endpoint test function
      tools: PCI: Add sample test script to invoke pcitest
      tools: PCI: Add a userspace tool to test PCI endpoint
      Documentation: misc-devices: Add Documentation for pci-endpoint-test driver
      misc: Add host side PCI driver for PCI test function device
      PCI: Add device IDs for DRA74x and DRA72x
      dt-bindings: PCI: dra7xx: Add DT bindings to enable unaligned access
      PCI: dwc: dra7xx: Workaround for errata id i870
      dt-bindings: PCI: dra7xx: Add DT bindings for PCI dra7xx EP mode
      PCI: dwc: dra7xx: Add EP mode support
      PCI: dwc: dra7xx: Facilitate wrapper and MSI interrupts to be enabled independently
      dt-bindings: PCI: Add DT bindings for PCI designware EP mode
      PCI: dwc: designware: Add EP mode support
      Documentation: PCI: Add binding documentation for pci-test endpoint function
      ixgbe: Use pcie_flr() instead of duplicating it
      IB/hfi1: Use pcie_flr() instead of duplicating it
      PCI: imx6: Fix spelling mistake: "contol" -> "control"
      ...

8f3207c7ea  Merge tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
3146c8f4de  Merge branch 'pci/remove' into next
857f864014  Merge tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
ea094f3c83  Merge tag 'hwmon-for-linus-v4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
8adac26418  Add linux-next specific files for 20170602
+-------------------------------------------+------------+------------+------------+------------+---------------+
|                                           | 8f3207c7ea | 3146c8f4de | 857f864014 | ea094f3c83 | next-20170602 |
+-------------------------------------------+------------+------------+------------+------------+---------------+
| boot_successes                            | 32         | 28         | 0          | 0          | 0             |
| boot_failures                             | 0          | 7          | 11         | 11         | 5             |
| BUG:kernel_hang_in_boot_stage             | 0          | 5          |            |            |               |
| INFO:rcu_sched_self-detected_stall_on_CPU | 0          | 1          |            |            |               |
| invoked_oom-killer:gfp_mask=0x            | 0          | 2          |            |            |               |
| Mem-Info                                  | 0          | 2          |            |            |               |
| Out_of_memory:Kill_process                | 0          | 2          |            |            |               |
| BUG:unable_to_handle_kernel               | 0          | 0          | 11         | 11         | 5             |
| Oops:#[##]                                | 0          | 0          | 11         | 11         | 5             |
| Kernel_panic-not_syncing:Fatal_exception  | 0          | 0          | 11         | 11         | 5             |
+-------------------------------------------+------------+------------+------------+------------+---------------+

[   14.402240] CHRDEV "cmx" major number 227 goes below the dynamic allocation range
[   14.404288] Hangcheck: starting hangcheck timer 0.9.1 (tick is 180 seconds, margin is 60 seconds).
[   14.407442] CHRDEV "aux" major number 226 goes below the dynamic allocation range
[   14.409430] [drm] radeon kernel modesetting enabled.
[   14.410875] [drm] amdgpu kernel modesetting enabled.
[   14.412564] BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8
[   14.414458] IP: down_write+0x2a/0x6c
[   14.415544] PGD 0 
[   14.415546] P4D 0 
[   14.416246] 
[   14.417528] Oops: 0002 [#1] SMP KASAN
[   14.418502] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.11.0-11362-g857f864 #1
[   14.420274] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014
[   14.422677] task: ffff880018589000 task.stack: ffff8800185a0000
[   14.424022] RIP: 0010:down_write+0x2a/0x6c
[   14.425088] RSP: 0000:ffff8800185a7c38 EFLAGS: 00010282
[   14.426324] RAX: 00000000000000a8 RBX: 00000000000000a8 RCX: 0000000000000000
[   14.427872] RDX: ffffffff00000001 RSI: 0000000000000034 RDI: ffff88001858901c
[   14.429438] RBP: ffff8800185a7c48 R08: 00000000006d6567 R09: ffffed0002e928b0
[   14.431062] R10: 0000000000000004 R11: 0000000000000001 R12: ffff880013597500
[   14.432616] R13: ffff8800185a7ce8 R14: ffff880013597530 R15: 0000000000000000
[   14.434286] FS:  0000000000000000(0000) GS:ffff880018a00000(0000) knlGS:0000000000000000
[   14.436222] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   14.437659] CR2: 00000000000000a8 CR3: 000000000d426000 CR4: 00000000000006f0
[   14.439266] Call Trace:
[   14.440069]  start_creating+0x91/0x1ad
[   14.441228]  debugfs_create_dir+0x23/0x3ce
[   14.442263]  drm_debugfs_init+0x10c/0x411
[   14.443299]  ? drm_debugfs_create_files+0x420/0x420
[   14.444697]  ? __kmalloc_track_caller+0xe8/0x1c4
[   14.445927]  ? memcpy+0x45/0x4c
[   14.446804]  drm_minor_register+0xb4/0x228
[   14.447888]  drm_dev_register+0x135/0x665
[   14.448808]  ? vmwgfx_init+0x5a/0x5a
[   14.449652]  vgem_init+0x40/0x61
[   14.450395]  do_one_initcall+0x117/0x21e
[   14.451241]  ? start_kernel+0x603/0x603
[   14.452074]  ? __wake_up+0x3f/0x4a
[   14.452915]  kernel_init_freeable+0x425/0x4dd
[   14.453826]  ? rest_init+0xaa/0xaa
[   14.454621]  kernel_init+0x13/0x176
[   14.455405]  ? rest_init+0xaa/0xaa
[   14.456172]  ret_from_fork+0x2c/0x40
[   14.456988] Code: df 55 48 89 e5 41 54 53 48 89 fb 31 d2 be 34 00 00 00 48 c7 c7 60 d2 c7 a2 e8 e3 15 d6 fb 48 ba 01 00 00 00 ff ff ff ff 48 89 d8 <f0> 48 0f c1 10 85 d2 74 05 e8 33 e4 cf fc 65 4c 8b 24 25 00 73 
[   14.460590] RIP: down_write+0x2a/0x6c RSP: ffff8800185a7c38
[   14.461759] CR2: 00000000000000a8
[   14.462514] ---[ end trace 9e6a3be2423379f2 ]---
[   14.463456] Kernel panic - not syncing: Fatal exception

                                                          # HH:MM RESULT GOOD BAD GOOD_BUT_DIRTY DIRTY_NOT_BAD
git bisect start 5ed02dbb497422bf225783f46e6eadd237d23d6b v4.11 --
git bisect  bad c81ee18e97e4e3162169a749eb7f2b79b3510c7a  # 12:47  B      0     1   12   0  Merge tag 'armsoc-defconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
git bisect good 2f34c1231bfc9f2550f934acb268ac7315fb3837  # 13:09  G     11     0    0   0  Merge tag 'drm-for-v4.12' of git://people.freedesktop.org/~airlied/linux
git bisect good 221656e7c4ce342b99c31eca96c1cbb6d1dce45f  # 13:40  G     11     0    1   1  Merge tag 'sound-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
git bisect good ab182e67ec99ea0c8d7435a32a4a1ed9bb02559a  # 14:03  G     10     0    0   2  Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
git bisect good 13e0988140374123bead1dd27c287354cb95108e  # 14:44  G     11     0    0   0  docs: complete bumping minimal GNU Make version to 3.81
git bisect  bad 857f8640147c9fb43f20e43cbca6452710e1ca5d  # 14:56  B      0     3   14   0  Merge tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
git bisect good d9dc089583ebf28d6f02b995e2d71c85965660f9  # 15:25  G     11     0    0   2  Merge tag 'xtensa-20170507' of git://github.com/jcmvbkbc/linux-xtensa
git bisect good 2d3e4866dea96b0506395b47bfefb234f2088dac  # 15:47  G     11     0    0   1  Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
git bisect good bf5f89463f5b3109a72ed13ca62b57e90213387d  # 16:02  G     10     0    0   0  Merge branch 'akpm' (patches from Andrew)
git bisect good 8f3207c7eab9d885cc64c778416537034a7d9c5b  # 16:23  G     10     0    1   1  Merge tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
git bisect good 27e99676f0f15692d2b70efb8e697d9cf7091362  # 16:49  G     11     0    0   2  Merge branch 'pci/iommu' into next
git bisect good acc886ec934980a45ae8962dbe88e221a40c77a2  # 17:09  G     11     0    0   2  Merge branch 'pci/pm' into next
git bisect good fcdb10d6b179fde41ca94d032afda8f4ed796b8e  # 17:35  G     11     0    2   2  ia64: Remove redundant checks for WC in pci_mmap_page_range()
git bisect good 889e4dd916a1f4dc7f9e6220fed26d811e39ca71  # 18:05  G     11     0    0   0  Merge branch 'pci/resource-mmap' into next
git bisect good 48f52d1a8ca9f1aff3ffad8e35b6c56eafa17b9b  # 18:20  G     10     0    0   0  PCI: Call pcie_flr() from reset_chelsio_generic_dev()
git bisect good ef1b5dad5a386885998d11eb45ca7fd183079965  # 18:45  G     10     0    0   2  Merge branch 'pci/virtualization' into next
git bisect good 3146c8f4de9b0858794a902f273aec13f168596e  # 19:02  G     10     0    0   0  Merge branch 'pci/remove' into next
# first bad commit: [857f8640147c9fb43f20e43cbca6452710e1ca5d] Merge tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
git bisect good 8f3207c7eab9d885cc64c778416537034a7d9c5b  # 19:16  G     32     0    0   1  Merge tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
git bisect good 3146c8f4de9b0858794a902f273aec13f168596e  # 19:35  G     31     0    3   4  Merge branch 'pci/remove' into next
# extra tests with CONFIG_DEBUG_INFO_REDUCED
git bisect  bad 857f8640147c9fb43f20e43cbca6452710e1ca5d  # 19:49  B      0     4   15   0  Merge tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
# extra tests on HEAD of linux-devel/devel-spot-201706041110
git bisect  bad 9a82652c052ee717f7fb831b6c375109d755344d  # 19:54  B      0    15   29   0  0day head guard for 'devel-spot-201706041110'
# extra tests on tree/branch linus/master
git bisect  bad ea094f3c830a67f252677aacba5d04ebcf55c4d9  # 20:09  B      0     1   12   0  Merge tag 'hwmon-for-linus-v4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
# extra tests on tree/branch linux-next/master
git bisect  bad 8adac2641862695ac273c94b85fdd5574e2804bb  # 20:27  B      0     2   13   0  Add linux-next specific files for 20170602

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