Commits · bd37f21e9f85e598be452b4817292bbe601efcd0 · Kirill Smelkov / linux

26 Jan, 2019 10 commits

arm64: perf: set suppress_bind_attrs flag to true · bd37f21e

Anders Roxell authored Oct 17, 2018

[ Upstream commit 81e9fa8b ]

The armv8_pmuv3 driver doesn't have a remove function, and when the test
'CONFIG_DEBUG_TEST_DRIVER_REMOVE=y' is enabled, the following Call trace
can be seen.

[    1.424287] Failed to register pmu: armv8_pmuv3, reason -17
[    1.424870] WARNING: CPU: 0 PID: 1 at ../kernel/events/core.c:11771 perf_event_sysfs_init+0x98/0xdc
[    1.425220] Modules linked in:
[    1.425531] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W         4.19.0-rc7-next-20181012-00003-ge7a97b1ad77b-dirty #35
[    1.425951] Hardware name: linux,dummy-virt (DT)
[    1.426212] pstate: 80000005 (Nzcv daif -PAN -UAO)
[    1.426458] pc : perf_event_sysfs_init+0x98/0xdc
[    1.426720] lr : perf_event_sysfs_init+0x98/0xdc
[    1.426908] sp : ffff00000804bd50
[    1.427077] x29: ffff00000804bd50 x28: ffff00000934e078
[    1.427429] x27: ffff000009546000 x26: 0000000000000007
[    1.427757] x25: ffff000009280710 x24: 00000000ffffffef
[    1.428086] x23: ffff000009408000 x22: 0000000000000000
[    1.428415] x21: ffff000009136008 x20: ffff000009408730
[    1.428744] x19: ffff80007b20b400 x18: 000000000000000a
[    1.429075] x17: 0000000000000000 x16: 0000000000000000
[    1.429418] x15: 0000000000000400 x14: 2e79726f74636572
[    1.429748] x13: 696420656d617320 x12: 656874206e692065
[    1.430060] x11: 6d616e20656d6173 x10: 2065687420687469
[    1.430335] x9 : ffff00000804bd50 x8 : 206e6f7361657220
[    1.430610] x7 : 2c3376756d705f38 x6 : ffff00000954d7ce
[    1.430880] x5 : 0000000000000000 x4 : 0000000000000000
[    1.431226] x3 : 0000000000000000 x2 : ffffffffffffffff
[    1.431554] x1 : 4d151327adc50b00 x0 : 0000000000000000
[    1.431868] Call trace:
[    1.432102]  perf_event_sysfs_init+0x98/0xdc
[    1.432382]  do_one_initcall+0x6c/0x1a8
[    1.432637]  kernel_init_freeable+0x1bc/0x280
[    1.432905]  kernel_init+0x18/0x160
[    1.433115]  ret_from_fork+0x10/0x18
[    1.433297] ---[ end trace 27fd415390eb9883 ]---

Rework to set suppress_bind_attrs flag to avoid removing the device when
CONFIG_DEBUG_TEST_DRIVER_REMOVE=y, since there's no real reason to
remove the armv8_pmuv3 driver.

Cc: Arnd Bergmann <arnd@arndb.de>
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

bd37f21e

MIPS: SiByte: Enable swiotlb for SWARM, LittleSur and BigSur · 8ac4ad06

Maciej W. Rozycki authored Nov 13, 2018

[ Upstream commit e4849aff ]

The Broadcom SiByte BCM1250, BCM1125, and BCM1125H SOCs have an onchip
DRAM controller that supports memory amounts of up to 16GiB, and due to
how the address decoder has been wired in the SOC any memory beyond 1GiB
is actually mapped starting from 4GiB physical up, that is beyond the
32-bit addressable limit[1].  Consequently if the maximum amount of
memory has been installed, then it will span up to 19GiB.

Many of the evaluation boards we support that are based on one of these
SOCs have their memory soldered and the amount present fits in the
32-bit address range.  The BCM91250A SWARM board however has actual DIMM
slots and accepts, depending on the peripherals revision of the SOC, up
to 4GiB or 8GiB of memory in commercially available JEDEC modules[2].
I believe this is also the case with the BCM91250C2 LittleSur board.
This means that up to either 3GiB or 7GiB of memory requires 64-bit
addressing to access.

I believe the BCM91480B BigSur board, which has the BCM1480 SOC instead,
accepts at least as much memory, although I have no documentation or
actual hardware available to verify that.

Both systems have PCI slots installed for use by any PCI option boards,
including ones that only support 32-bit addressing (additionally the
32-bit PCI host bridge of the BCM1250, BCM1125, and BCM1125H SOCs limits
addressing to 32-bits), and there is no IOMMU available.  Therefore for
PCI DMA to work in the presence of memory beyond enable swiotlb for the
affected systems.

All the other SOC onchip DMA devices use 40-bit addressing and therefore
can address the whole memory, so only enable swiotlb if PCI support and
support for DMA beyond 4GiB have been both enabled in the configuration
of the kernel.

This shows up as follows:

Broadcom SiByte BCM1250 B2 @ 800 MHz (SB1 rev 2)
Board type: SiByte BCM91250A (SWARM)
Determined physical RAM map:
 memory: 000000000fe7fe00 @ 0000000000000000 (usable)
 memory: 000000001ffffe00 @ 0000000080000000 (usable)
 memory: 000000000ffffe00 @ 00000000c0000000 (usable)
 memory: 0000000087fffe00 @ 0000000100000000 (usable)
software IO TLB: mapped [mem 0xcbffc000-0xcfffc000] (64MB)

in the bootstrap log and removes failures like these:

defxx 0000:02:00.0: dma_direct_map_page: overflow 0x0000000185bc6080+4608 of device mask ffffffff bus mask 0
fddi0: Receive buffer allocation failed
fddi0: Adapter open failed!
IP-Config: Failed to open fddi0
defxx 0000:09:08.0: dma_direct_map_page: overflow 0x0000000185bc6080+4608 of device mask ffffffff bus mask 0
fddi1: Receive buffer allocation failed
fddi1: Adapter open failed!
IP-Config: Failed to open fddi1

when memory beyond 4GiB is handed out to devices that can only do 32-bit
addressing.

This updates commit cce335ae ("[MIPS] 64-bit Sibyte kernels need
DMA32.").

References:

[1] "BCM1250/BCM1125/BCM1125H User Manual", Revision 1250_1125-UM100-R,
    Broadcom Corporation, 21 Oct 2002, Section 3: "System Overview",
    "Memory Map", pp. 34-38

[2] "BCM91250A User Manual", Revision 91250A-UM100-R, Broadcom
    Corporation, 18 May 2004, Section 3: "Physical Description",
    "Supported DRAM", p. 23
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
[paul.burton@mips.com: Remove GPL text from dma.c; SPDX tag covers it]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Patchwork: https://patchwork.linux-mips.org/patch/21108/
References: cce335ae ("[MIPS] 64-bit Sibyte kernels need DMA32.")
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

8ac4ad06

ALSA: oxfw: add support for APOGEE duet FireWire · 1871002d

Takashi Sakamoto authored Nov 13, 2018

[ Upstream commit fba43f45 ]

This commit adds support for APOGEE duet FireWire, launched 2007, already
discontinued. This model uses Oxford Semiconductor FW971 as its
communication engine. Below is information on Configuration ROM of this
unit. The unit supports some AV/C commands defined by Audio subunit
specification and vendor dependent commands.

$ ./hinawa-config-rom-printer /dev/fw1
{ 'bus-info': { 'adj': False,
                'bmc': False,
                'chip_ID': 42949742248,
                'cmc': False,
                'cyc_clk_acc': 255,
                'generation': 0,
                'imc': False,
                'isc': True,
                'link_spd': 3,
                'max_ROM': 0,
                'max_rec': 64,
                'name': '1394',
                'node_vendor_ID': 987,
                'pmc': False},
  'root-directory': [ ['VENDOR', 987],
                      ['DESCRIPTOR', 'Apogee Electronics'],
                      ['MODEL', 122333],
                      ['DESCRIPTOR', 'Duet'],
                      [ 'NODE_CAPABILITIES',
                        { 'addressing': {'64': True, 'fix': True, 'prv': False},
                          'misc': {'int': False, 'ms': False, 'spt': True},
                          'state': { 'atn': False,
                                     'ded': False,
                                     'drq': True,
                                     'elo': False,
                                     'init': False,
                                     'lst': True,
                                     'off': False},
                          'testing': {'bas': False, 'ext': False}}],
                      [ 'UNIT',
                        [ ['SPECIFIER_ID', 41005],
                          ['VERSION', 65537],
                          ['MODEL', 122333],
                          ['DESCRIPTOR', 'Duet']]]]}
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

1871002d

serial: set suppress_bind_attrs flag only if builtin · e9770160

Anders Roxell authored Oct 30, 2018

[ Upstream commit 64609794 ]

When the test 'CONFIG_DEBUG_TEST_DRIVER_REMOVE=y' is enabled,
arch_initcall(pl011_init) came before subsys_initcall(default_bdi_init).
devtmpfs gets killed because we try to remove a file and decrement the
wb reference count before the noop_backing_device_info gets initialized.

[    0.332075] Serial: AMBA PL011 UART driver
[    0.485276] 9000000.pl011: ttyAMA0 at MMIO 0x9000000 (irq = 39, base_baud = 0) is a PL011 rev1
[    0.502382] console [ttyAMA0] enabled
[    0.515710] Unable to handle kernel paging request at virtual address 0000800074c12000
[    0.516053] Mem abort info:
[    0.516222]   ESR = 0x96000004
[    0.516417]   Exception class = DABT (current EL), IL = 32 bits
[    0.516641]   SET = 0, FnV = 0
[    0.516826]   EA = 0, S1PTW = 0
[    0.516984] Data abort info:
[    0.517149]   ISV = 0, ISS = 0x00000004
[    0.517339]   CM = 0, WnR = 0
[    0.517553] [0000800074c12000] user address but active_mm is swapper
[    0.517928] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[    0.518305] Modules linked in:
[    0.518839] CPU: 0 PID: 13 Comm: kdevtmpfs Not tainted 4.19.0-rc5-next-20180928-00002-g2ba39ab0cd01-dirty #82
[    0.519307] Hardware name: linux,dummy-virt (DT)
[    0.519681] pstate: 80000005 (Nzcv daif -PAN -UAO)
[    0.519959] pc : __destroy_inode+0x94/0x2a8
[    0.520212] lr : __destroy_inode+0x78/0x2a8
[    0.520401] sp : ffff0000098c3b20
[    0.520590] x29: ffff0000098c3b20 x28: 00000000087a3714
[    0.520904] x27: 0000000000002000 x26: 0000000000002000
[    0.521179] x25: ffff000009583000 x24: 0000000000000000
[    0.521467] x23: ffff80007bb52000 x22: ffff80007bbaa7c0
[    0.521737] x21: ffff0000093f9338 x20: 0000000000000000
[    0.522033] x19: ffff80007bbb05d8 x18: 0000000000000400
[    0.522376] x17: 0000000000000000 x16: 0000000000000000
[    0.522727] x15: 0000000000000400 x14: 0000000000000400
[    0.523068] x13: 0000000000000001 x12: 0000000000000001
[    0.523421] x11: 0000000000000000 x10: 0000000000000970
[    0.523749] x9 : ffff0000098c3a60 x8 : ffff80007bbab190
[    0.524017] x7 : ffff80007bbaa880 x6 : 0000000000000c88
[    0.524305] x5 : ffff0000093d96c8 x4 : 61c8864680b583eb
[    0.524567] x3 : ffff0000093d6180 x2 : ffffffffffffffff
[    0.524872] x1 : 0000800074c12000 x0 : 0000800074c12000
[    0.525207] Process kdevtmpfs (pid: 13, stack limit = 0x(____ptrval____))
[    0.525529] Call trace:
[    0.525806]  __destroy_inode+0x94/0x2a8
[    0.526108]  destroy_inode+0x34/0x88
[    0.526370]  evict+0x144/0x1c8
[    0.526636]  iput+0x184/0x230
[    0.526871]  dentry_unlink_inode+0x118/0x130
[    0.527152]  d_delete+0xd8/0xe0
[    0.527420]  vfs_unlink+0x240/0x270
[    0.527665]  handle_remove+0x1d8/0x330
[    0.527875]  devtmpfsd+0x138/0x1c8
[    0.528085]  kthread+0x14c/0x158
[    0.528291]  ret_from_fork+0x10/0x18
[    0.528720] Code: 92800002 aa1403e0 d538d081 8b010000 (c85f7c04)
[    0.529367] ---[ end trace 5a3dee47727f877c ]---

Rework to set suppress_bind_attrs flag to avoid removing the device when
CONFIG_DEBUG_TEST_DRIVER_REMOVE=y. This applies for pic32_uart and
xilinx_uartps as well.
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

e9770160

writeback: don't decrement wb->refcnt if !wb->bdi · db16eb55

Anders Roxell authored Oct 30, 2018

[ Upstream commit 347a28b5 ]

This happened while running in qemu-system-aarch64, the AMBA PL011 UART
driver when enabling CONFIG_DEBUG_TEST_DRIVER_REMOVE.
arch_initcall(pl011_init) came before subsys_initcall(default_bdi_init),
devtmpfs' handle_remove() crashes because the reference count is a NULL
pointer only because wb->bdi hasn't been initialized yet.

Rework so that wb_put have an extra check if wb->bdi before decrement
wb->refcnt and also add a WARN_ON_ONCE to get a warning if it happens again
in other drivers.

Fixes: 52ebea74 ("writeback: make backing_dev_info host cgroup-specific bdi_writebacks")
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

db16eb55

e1000e: allow non-monotonic SYSTIM readings · de390c26

Miroslav Lichvar authored Oct 23, 2018

[ Upstream commit e1f65b0d ]

It seems with some NICs supported by the e1000e driver a SYSTIM reading
may occasionally be few microseconds before the previous reading and if
enabled also pass e1000e_sanitize_systim() without reaching the maximum
number of rereads, even if the function is modified to check three
consecutive readings (i.e. it doesn't look like a double read error).
This causes an underflow in the timecounter and the PHC time jumps hours
ahead.

This was observed on 82574, I217 and I219. The fastest way to reproduce
it is to run a program that continuously calls the PTP_SYS_OFFSET ioctl
on the PHC.

Modify e1000e_phc_gettime() to use timecounter_cyc2time() instead of
timecounter_read() in order to allow non-monotonic SYSTIM readings and
prevent the PHC from jumping.

Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Acked-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

de390c26

platform/x86: asus-wmi: Tell the EC the OS will handle the display off hotkey · dfc711a4

João Paulo Rechi Vita authored Oct 31, 2018

[ Upstream commit 78f3ac76 ]

In the past, Asus firmwares would change the panel backlight directly
through the EC when the display off hotkey (Fn+F7) was pressed, and
only notify the OS of such change, with 0x33 when the LCD was ON and
0x34 when the LCD was OFF. These are currently mapped to
KEY_DISPLAYTOGGLE and KEY_DISPLAY_OFF, respectively.

Most recently the EC on Asus most machines lost ability to toggle the
LCD backlight directly, but unless the OS informs the firmware it is
going to handle the display toggle hotkey events, the firmware still
tries change the brightness through the EC, to no effect. The end result
is a long list (at Endless we counted 11) of Asus laptop models where
the display toggle hotkey does not perform any action. Our firmware
engineers contacts at Asus were surprised that there were still machines
out there with the old behavior.

Calling WMNB(ASUS_WMI_DEVID_BACKLIGHT==0x00050011, 2) on the _WDG device
tells the firmware that it should let the OS handle the display toggle
event, in which case it will simply notify the OS of a key press with
0x35, as shown by the DSDT excerpts bellow.

 Scope (_SB)
 {
     (...)

     Device (ATKD)
     {
         (...)

         Name (_WDG, Buffer (0x28)
         {
             /* 0000 */  0xD0, 0x5E, 0x84, 0x97, 0x6D, 0x4E, 0xDE, 0x11,
             /* 0008 */  0x8A, 0x39, 0x08, 0x00, 0x20, 0x0C, 0x9A, 0x66,
             /* 0010 */  0x4E, 0x42, 0x01, 0x02, 0x35, 0xBB, 0x3C, 0x0B,
             /* 0018 */  0xC2, 0xE3, 0xED, 0x45, 0x91, 0xC2, 0x4C, 0x5A,
             /* 0020 */  0x6D, 0x19, 0x5D, 0x1C, 0xFF, 0x00, 0x01, 0x08
         })
         Method (WMNB, 3, Serialized)
         {
             CreateDWordField (Arg2, Zero, IIA0)
             CreateDWordField (Arg2, 0x04, IIA1)
             Local0 = (Arg1 & 0xFFFFFFFF)

             (...)

             If ((Local0 == 0x53564544))
             {
                 (...)

                 If ((IIA0 == 0x00050011))
                 {
                     If ((IIA1 == 0x02))
                     {
                         ^^PCI0.SBRG.EC0.SPIN (0x72, One)
                         ^^PCI0.SBRG.EC0.BLCT = One
                     }

                     Return (One)
                 }
             }
             (...)
         }
         (...)
     }
     (...)
 }
 (...)

 Scope (_SB.PCI0.SBRG.EC0)
 {
     (...)

     Name (BLCT, Zero)

     (...)

     Method (_Q10, 0, NotSerialized)  // _Qxx: EC Query
     {
         If ((BLCT == Zero))
         {
             Local0 = One
             Local0 = RPIN (0x72)
             Local0 ^= One
             SPIN (0x72, Local0)
             If (ATKP)
             {
                 Local0 = (0x34 - Local0)
                 ^^^^ATKD.IANE (Local0)
             }
         }
         ElseIf ((BLCT == One))
         {
             If (ATKP)
             {
                 ^^^^ATKD.IANE (0x35)
             }
         }
     }
     (...)
 }
Signed-off-by: João Paulo Rechi Vita <jprvita@endlessm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

dfc711a4

ipv6: Take rcu_read_lock in __inet6_bind for mapped addresses · 2af7450e

David Ahern authored Jan 05, 2019

[ Upstream commit d4a7e9bb ]

I realized the last patch calls dev_get_by_index_rcu in a branch not
holding the rcu lock. Add the calls to rcu_read_lock and rcu_read_unlock.

Fixes: ec90ad33 ("ipv6: Consider sk_bound_dev_if when binding a socket to a v4 mapped address")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2af7450e

ipv6: Consider sk_bound_dev_if when binding a socket to a v4 mapped address · dbbbd01e

David Ahern authored Jan 04, 2019

[ Upstream commit ec90ad33 ]

Similar to c5ee0663 ("ipv6: Consider sk_bound_dev_if when binding a
socket to an address"), binding a socket to v4 mapped addresses needs to
consider if the socket is bound to a device.

This problem also exists from the beginning of git history.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dbbbd01e

r8169: Add support for new Realtek Ethernet · eb0e073f

Kai-Heng Feng authored Jan 02, 2019

[ Upstream commit 36352991 ]

There are two new Realtek Ethernet devices which are re-branded r8168h.
Add the IDs to to support them.
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eb0e073f

23 Jan, 2019 30 commits

Linux 4.9.152 · ef50e305
Greg Kroah-Hartman authored Jan 23, 2019

ef50e305

nbd: Use set_blocksize() to set device blocksize · f3fc8899

Jan Kara authored Jan 14, 2019

commit c8a83a6b upstream.

NBD can update block device block size implicitely through
bd_set_size(). Make it explicitely set blocksize with set_blocksize() as
this behavior of bd_set_size() is going away.

CC: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

f3fc8899

nbd: set the logical and physical blocksize properly · eb108751

Josef Bacik authored Feb 13, 2017

commit e544541b upstream.

We noticed when trying to do O_DIRECT to an export on the server side
that we were getting requests smaller than the 4k sectorsize of the
device.  This is because the client isn't setting the logical and
physical blocksizes properly for the underlying device.  Fix this up by
setting the queue blocksizes and then calling bd_set_size.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eb108751

media: vb2: be sure to unlock mutex on errors · ef32aca7

Mauro Carvalho Chehab authored Nov 23, 2018

commit c06ef2e9 upstream.

As reported by smatch:
drivers/media/common/videobuf2/videobuf2-core.c: drivers/media/common/videobuf2/videobuf2-core.c:2159 vb2_mmap() warn: inconsistent returns 'mutex:&q->mmap_lock'.
  Locked on:   line 2148
  Unlocked on: line 2100
               line 2108
               line 2113
               line 2118
               line 2156
               line 2159

There is one error condition that doesn't unlock a mutex.

Fixes: cd26d1c4 ("media: vb2: vb2_mmap: move lock up")
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ef32aca7

mm, memcg: fix reclaim deadlock with writeback · 5cf3e5ff

Michal Hocko authored Jan 08, 2019

commit 63f3655f upstream.

Liu Bo has experienced a deadlock between memcg (legacy) reclaim and the
ext4 writeback

  task1:
    wait_on_page_bit+0x82/0xa0
    shrink_page_list+0x907/0x960
    shrink_inactive_list+0x2c7/0x680
    shrink_node_memcg+0x404/0x830
    shrink_node+0xd8/0x300
    do_try_to_free_pages+0x10d/0x330
    try_to_free_mem_cgroup_pages+0xd5/0x1b0
    try_charge+0x14d/0x720
    memcg_kmem_charge_memcg+0x3c/0xa0
    memcg_kmem_charge+0x7e/0xd0
    __alloc_pages_nodemask+0x178/0x260
    alloc_pages_current+0x95/0x140
    pte_alloc_one+0x17/0x40
    __pte_alloc+0x1e/0x110
    alloc_set_pte+0x5fe/0xc20
    do_fault+0x103/0x970
    handle_mm_fault+0x61e/0xd10
    __do_page_fault+0x252/0x4d0
    do_page_fault+0x30/0x80
    page_fault+0x28/0x30

  task2:
    __lock_page+0x86/0xa0
    mpage_prepare_extent_to_map+0x2e7/0x310 [ext4]
    ext4_writepages+0x479/0xd60
    do_writepages+0x1e/0x30
    __writeback_single_inode+0x45/0x320
    writeback_sb_inodes+0x272/0x600
    __writeback_inodes_wb+0x92/0xc0
    wb_writeback+0x268/0x300
    wb_workfn+0xb4/0x390
    process_one_work+0x189/0x420
    worker_thread+0x4e/0x4b0
    kthread+0xe6/0x100
    ret_from_fork+0x41/0x50

He adds
 "task1 is waiting for the PageWriteback bit of the page that task2 has
  collected in mpd->io_submit->io_bio, and tasks2 is waiting for the
  LOCKED bit the page which tasks1 has locked"

More precisely task1 is handling a page fault and it has a page locked
while it charges a new page table to a memcg.  That in turn hits a
memory limit reclaim and the memcg reclaim for legacy controller is
waiting on the writeback but that is never going to finish because the
writeback itself is waiting for the page locked in the #PF path.  So
this is essentially ABBA deadlock:

                                        lock_page(A)
                                        SetPageWriteback(A)
                                        unlock_page(A)
  lock_page(B)
                                        lock_page(B)
  pte_alloc_pne
    shrink_page_list
      wait_on_page_writeback(A)
                                        SetPageWriteback(B)
                                        unlock_page(B)

                                        # flush A, B to clear the writeback

This accumulating of more pages to flush is used by several filesystems
to generate a more optimal IO patterns.

Waiting for the writeback in legacy memcg controller is a workaround for
pre-mature OOM killer invocations because there is no dirty IO
throttling available for the controller.  There is no easy way around
that unfortunately.  Therefore fix this specific issue by pre-allocating
the page table outside of the page lock.  We have that handy
infrastructure for that already so simply reuse the fault-around pattern
which already does this.

There are probably other hidden __GFP_ACCOUNT | GFP_KERNEL allocations
from under a fs page locked but they should be really rare.  I am not
aware of a better solution unfortunately.

[akpm@linux-foundation.org: fix mm/memory.c:__do_fault()]
[akpm@linux-foundation.org: coding-style fixes]
[mhocko@kernel.org: enhance comment, per Johannes]
  Link: http://lkml.kernel.org/r/20181214084948.GA5624@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20181213092221.27270-1-mhocko@kernel.org
Fixes: c3b94f44 ("memcg: further prevent OOM with too many dirty pages")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Liu Bo <bo.liu@linux.alibaba.com>
Debugged-by: Liu Bo <bo.liu@linux.alibaba.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org>
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>

5cf3e5ff

drm/fb-helper: Ignore the value of fb_var_screeninfo.pixclock · a5a0bcbc

Ivan Mironov authored Jan 08, 2019

commit 66a8d5bf upstream.

Strict requirement of pixclock to be zero breaks support of SDL 1.2
which contains hardcoded table of supported video modes with non-zero
pixclock values[1].

To better understand which pixclock values are considered valid and how
driver should handle these values, I briefly examined few existing fbdev
drivers and documentation in Documentation/fb/. And it looks like there
are no strict rules on that and actual behaviour varies:

	* some drivers treat (pixclock == 0) as "use defaults" (uvesafb.c);
	* some treat (pixclock == 0) as invalid value which leads to
	  -EINVAL (clps711x-fb.c);
	* some pass converted pixclock value to hardware (uvesafb.c);
	* some are trying to find nearest value from predefined table
          (vga16fb.c, video_gx.c).

Given this, I believe that it should be safe to just ignore this value if
changing is not supported. It seems that any portable fbdev application
which was not written only for one specific device working under one
specific kernel version should not rely on any particular behaviour of
pixclock anyway.

However, while enabling SDL1 applications to work out of the box when
there is no /etc/fb.modes with valid settings, this change affects the
video mode choosing logic in SDL. Depending on current screen
resolution, contents of /etc/fb.modes and resolution requested by
application, this may lead to user-visible difference (not always):
image will be displayed in a right way, but it will be aligned to the
left instead of center. There is no "right behaviour" here as well, as
emulated fbdev, opposing to old fbdev drivers, simply ignores any
requsts of video mode changes with resolutions smaller than current.

The easiest way to reproduce this problem is to install sdl-sopwith[2],
remove /etc/fb.modes file if it exists, and then try to run sopwith
from console without X. At least in Fedora 29, sopwith may be simply
installed from standard repositories.

[1] SDL 1.2.15 source code, src/video/fbcon/SDL_fbvideo.c, vesa_timings
[2] http://sdl-sopwith.sourceforge.net/Signed-off-by: Ivan Mironov <mironov.ivan@gmail.com>
Cc: stable@vger.kernel.org
Fixes: 79e53945 ("DRM: i915: add mode setting support")
Fixes: 771fe6b9 ("drm/radeon: introduce kernel modesetting for radeon hardware")
Fixes: 785b93ef ("drm/kms: move driver specific fb common code to helper functions (v2)")
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108072353.28078-3-mironov.ivan@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

a5a0bcbc

loop: Fix double mutex_unlock(&loop_ctl_mutex) in loop_control_ioctl() · 5d3cf501

Tetsuo Handa authored Nov 12, 2018

commit 628bd859 upstream.

Commit 0a42e99b ("loop: Get rid of loop_index_mutex") forgot to
remove mutex_unlock(&loop_ctl_mutex) from loop_control_ioctl() when
replacing loop_index_mutex with loop_ctl_mutex.

Fixes: 0a42e99b ("loop: Get rid of loop_index_mutex")
Reported-by: syzbot <syzbot+c0138741c2290fc5e63f@syzkaller.appspotmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

5d3cf501

loop: Get rid of loop_index_mutex · 6a8f1d8d

Jan Kara authored Nov 08, 2018

commit 0a42e99b upstream.

Now that loop_ctl_mutex is global, just get rid of loop_index_mutex as
there is no good reason to keep these two separate and it just
complicates the locking.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

6a8f1d8d

loop: Fold __loop_release into loop_release · 7d839c10

Jan Kara authored Nov 08, 2018

commit 967d1dc1 upstream.

__loop_release() has a single call site. Fold it there. This is
currently not a huge win but it will make following replacement of
loop_index_mutex more obvious.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

7d839c10

block/loop: Use global lock for ioctl() operation. · 3ae3d167

Tetsuo Handa authored Nov 08, 2018

commit 310ca162 upstream.

syzbot is reporting NULL pointer dereference [1] which is caused by
race condition between ioctl(loop_fd, LOOP_CLR_FD, 0) versus
ioctl(other_loop_fd, LOOP_SET_FD, loop_fd) due to traversing other
loop devices at loop_validate_file() without holding corresponding
lo->lo_ctl_mutex locks.

Since ioctl() request on loop devices is not frequent operation, we don't
need fine grained locking. Let's use global lock in order to allow safe
traversal at loop_validate_file().

Note that syzbot is also reporting circular locking dependency between
bdev->bd_mutex and lo->lo_ctl_mutex [2] which is caused by calling
blkdev_reread_part() with lock held. This patch does not address it.

[1] https://syzkaller.appspot.com/bug?id=f3cfe26e785d85f9ee259f385515291d21bd80a3
[2] https://syzkaller.appspot.com/bug?id=bf154052f0eea4bc7712499e4569505907d15889Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+bf89c128e05dd6c62523@syzkaller.appspotmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>