linux-stable.git/drivers, branch linux-5.5.y

scsi: target: fix hang when multiple threads try to destroy the same iscsi session

2020-04-21T07:06:45+00:00

[ Upstream commit 57c46e9f33da530a2485fa01aa27b6d18c28c796 ]

A number of hangs have been reported against the target driver; they are
due to the fact that multiple threads may try to destroy the iscsi session
at the same time. This may be reproduced for example when a "targetcli
iscsi/iqn.../tpg1 disable" command is executed while a logout operation is
underway.

When this happens, two or more threads may end up sleeping and waiting for
iscsit_close_connection() to execute "complete(session_wait_comp)".  Only
one of the threads will wake up and proceed to destroy the session
structure, the remaining threads will hang forever.

Note that if the blocked threads are somehow forced to wake up with
complete_all(), they will try to free the same iscsi session structure
destroyed by the first thread, causing double frees, memory corruptions
etc...

With this patch, the threads that want to destroy the iscsi session will
increase the session refcount and will set the "session_close" flag to 1;
then they wait for the driver to close the remaining active connections.
When the last connection is closed, iscsit_close_connection() will wake up
all the threads and will wait for the session's refcount to reach zero;
when this happens, iscsit_close_connection() will destroy the session
structure because no one is referencing it anymore.

 INFO: task targetcli:5971 blocked for more than 120 seconds.
       Tainted: P           OE    4.15.0-72-generic #81~16.04.1
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
 targetcli       D    0  5971      1 0x00000080
 Call Trace:
  __schedule+0x3d6/0x8b0
  ? vprintk_func+0x44/0xe0
  schedule+0x36/0x80
  schedule_timeout+0x1db/0x370
  ? __dynamic_pr_debug+0x8a/0xb0
  wait_for_completion+0xb4/0x140
  ? wake_up_q+0x70/0x70
  iscsit_free_session+0x13d/0x1a0 [iscsi_target_mod]
  iscsit_release_sessions_for_tpg+0x16b/0x1e0 [iscsi_target_mod]
  iscsit_tpg_disable_portal_group+0xca/0x1c0 [iscsi_target_mod]
  lio_target_tpg_enable_store+0x66/0xe0 [iscsi_target_mod]
  configfs_write_file+0xb9/0x120
  __vfs_write+0x1b/0x40
  vfs_write+0xb8/0x1b0
  SyS_write+0x5c/0xe0
  do_syscall_64+0x73/0x130
  entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Link: https://lore.kernel.org/r/20200313170656.9716-3-mlombard@redhat.com
Reported-by: Matt Coleman 
Tested-by: Matt Coleman 
Tested-by: Rahul Kundu 
Signed-off-by: Maurizio Lombardi 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: target: remove boilerplate code

2020-04-21T07:06:45+00:00

[ Upstream commit e49a7d994379278d3353d7ffc7994672752fb0ad ]

iscsit_free_session() is equivalent to iscsit_stop_session() followed by a
call to iscsit_close_session().

Link: https://lore.kernel.org/r/20200313170656.9716-2-mlombard@redhat.com
Tested-by: Rahul Kundu 
Signed-off-by: Maurizio Lombardi 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

irqchip/ti-sci-inta: Fix processing of masked irqs

2020-04-21T07:06:44+00:00

commit 3688b0db5c331f4ec3fa5eb9f670a4b04f530700 upstream.

The ti_sci_inta_irq_handler() does not take into account INTA IRQs state
(masked/unmasked) as it uses INTA_STATUS_CLEAR_j register to get INTA IRQs
status, which provides raw status value.
This causes hard IRQ handlers to be called or threaded handlers to be
scheduled many times even if corresponding INTA IRQ is masked.
Above, first of all, affects the LEVEL interrupts processing and causes
unexpected behavior up the system stack or crash.

Fix it by using the Interrupt Masked Status INTA_STATUSM_j register which
provides masked INTA IRQs status.

Fixes: 9f1463b86c13 ("irqchip/ti-sci-inta: Add support for Interrupt Aggregator driver")
Signed-off-by: Grygorii Strashko 
Signed-off-by: Marc Zyngier 
Reviewed-by: Lokesh Vutla 
Link: https://lore.kernel.org/r/20200408191532.31252-1-grygorii.strashko@ti.com
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

drm/i915/perf: Do not clear pollin for small user read buffers

2020-04-21T07:06:43+00:00

commit bcad588dea538a4fc173d16a90a005536ec8dbf2 upstream.

It is wrong to block the user thread in the next poll when OA data is
already available which could not fit in the user buffer provided in
the previous read. In several cases the exact user buffer size is not
known. Blocking user space in poll can lead to data loss when the
buffer size used is smaller than the available data.

This change fixes this issue and allows user space to read all OA data
even when using a buffer size smaller than the available data using
multiple non-blocking reads rather than staying blocked in poll till
the next timer interrupt.

v2: Fix ret value for blocking reads (Umesh)
v3: Mistake during patch send (Ashutosh)
v4: Remove -EAGAIN from comment (Umesh)
v5: Improve condition for clearing pollin and return (Lionel)
v6: Improve blocking read loop and other cleanups (Lionel)
v7: Added Cc stable

Testcase: igt/perf/polling-small-buf
Reviewed-by: Lionel Landwerlin 
Signed-off-by: Ashutosh Dixit 
Cc: Umesh Nerlige Ramappa 
Cc: 
Signed-off-by: Chris Wilson 
Link: https://patchwork.freedesktop.org/patch/msgid/20200403010120.3067-1-ashutosh.dixit@intel.com
(cherry-picked from commit 6352219c39c04ed3f9a8d1cf93f87c21753a213e)
Signed-off-by: Rodrigo Vivi 
Signed-off-by: Greg Kroah-Hartman

i2c: designware: platdrv: Remove DPM_FLAG_SMART_SUSPEND flag on BYT and CHT

2020-04-21T07:06:43+00:00

commit d79294d0de12ddd1420110813626d691f440b86f upstream.

We already set DPM_FLAG_SMART_PREPARE, so we completely skip all
callbacks (other then prepare) where possible, quoting from
dw_i2c_plat_prepare():

        /*
         * If the ACPI companion device object is present for this device, it
         * may be accessed during suspend and resume of other devices via I2C
         * operation regions, so tell the PM core and middle layers to avoid
         * skipping system suspend/resume callbacks for it in that case.
         */
        return !has_acpi_companion(dev);

Also setting the DPM_FLAG_SMART_SUSPEND will cause acpi_subsys_suspend()
to leave the controller runtime-suspended even if dw_i2c_plat_prepare()
returned 0.

Leaving the controller runtime-suspended normally, when the I2C controller
is suspended during the suspend_late phase, is not an issue because
the pm_runtime_get_sync() done by i2c_dw_xfer() will (runtime-)resume it.

But for dw I2C controllers on Bay- and Cherry-Trail devices acpi_lpss.c
leaves the controller alive until the suspend_noirq phase, because it may
be used by the _PS3 ACPI methods of PCI devices and PCI devices are left
powered on until the suspend_noirq phase.

Between the suspend_late and resume_early phases runtime-pm is disabled.
So for any ACPI I2C OPRegion accesses done after the suspend_late phase,
the pm_runtime_get_sync() done by i2c_dw_xfer() is a no-op and the
controller is left runtime-suspended.

i2c_dw_xfer() has a check to catch this condition (rather then waiting
for the I2C transfer to timeout because the controller is suspended).
acpi_subsys_suspend() leaving the controller runtime-suspended in
combination with an ACPI I2C OPRegion access done after the suspend_late
phase triggers this check, leading to the following error being logged
on a Bay Trail based Lenovo Thinkpad 8 tablet:

[   93.275882] i2c_designware 80860F41:00: Transfer while suspended
[   93.275993] WARNING: CPU: 0 PID: 412 at drivers/i2c/busses/i2c-designware-master.c:429 i2c_dw_xfer+0x239/0x280
...
[   93.276252] Workqueue: kacpi_notify acpi_os_execute_deferred
[   93.276267] RIP: 0010:i2c_dw_xfer+0x239/0x280
...
[   93.276340] Call Trace:
[   93.276366]  __i2c_transfer+0x121/0x520
[   93.276379]  i2c_transfer+0x4c/0x100
[   93.276392]  i2c_acpi_space_handler+0x219/0x510
[   93.276408]  ? up+0x40/0x60
[   93.276419]  ? i2c_acpi_notify+0x130/0x130
[   93.276433]  acpi_ev_address_space_dispatch+0x1e1/0x252
...

So since on BYT and CHT platforms we want ACPI I2c OPRegion accesses
to work until the suspend_noirq phase, we need the controller to be
runtime-resumed during the suspend phase if it is runtime-suspended
suspended at that time. This means that we must not set the
DPM_FLAG_SMART_SUSPEND on these platforms.

On BYT and CHT we already have a special ACCESS_NO_IRQ_SUSPEND flag
to make sure the controller stays functional until the suspend_noirq
phase. This commit makes the driver not set the DPM_FLAG_SMART_SUSPEND
flag when that flag is set.

Cc: stable@vger.kernel.org
Fixes: b30f2f65568f ("i2c: designware: Set IRQF_NO_SUSPEND flag for all BYT and CHT controllers")
Signed-off-by: Hans de Goede 
Reviewed-by: Andy Shevchenko 
Acked-by: Rafael J. Wysocki 
Acked-by: Jarkko Nikula 
Signed-off-by: Wolfram Sang 
Signed-off-by: Greg Kroah-Hartman

drm/amdgpu: fix the hw hang during perform system reboot and reset

2020-04-21T07:06:43+00:00

commit b2a7e9735ab2864330be9d00d7f38c961c28de5d upstream.

The system reboot failed as some IP blocks enter power gate before perform
hw resource destory. Meanwhile use unify interface to set device CGPG to ungate
state can simplify the amdgpu poweroff or reset ungate guard.

Fixes: 487eca11a321ef ("drm/amdgpu: fix gfx hang during suspend with video playback (v2)")
Signed-off-by: Prike Liang 
Tested-by: Mengbing Wang 
Tested-by: Paul Menzel 
Acked-by: Alex Deucher 
Signed-off-by: Alex Deucher 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

drm/amd/powerplay: force the trim of the mclk dpm_levels if OD is enabled

2020-04-21T07:06:43+00:00

commit 8c7f0a44b4b4ef16df8f44fbaee6d1f5d1593c83 upstream.

Should prevent flicker if PP_OVERDRIVE_MASK is set.

bug: https://bugs.freedesktop.org/show_bug.cgi?id=102646
bug: https://bugs.freedesktop.org/show_bug.cgi?id=108941
bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1088
bug: https://gitlab.freedesktop.org/drm/amd/-/issues/628

Signed-off-by: Sergei Lopatin 
Signed-off-by: Alex Deucher 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

net/mlx5e: Use preactivate hook to set the indirection table

2020-04-21T07:06:42+00:00

[ Upstream commit fe867cac9e1967c553e4ac2aece5fc8675258010 ]

mlx5e_ethtool_set_channels updates the indirection table before
switching to the new channels. If the switch fails, the indirection
table is new, but the channels are old, which is wrong. Fix it by using
the preactivate hook of mlx5e_safe_switch_channels to update the
indirection table at the stage when nothing can fail anymore.

As the code that updates the indirection table is now encapsulated into
a new function, use that function in the attach flow when the driver has
to reduce the number of channels, and prepare the code for the next
commit.

Fixes: 85082dba0a ("net/mlx5e: Correctly handle RSS indirection table when changing number of channels")
Signed-off-by: Maxim Mikityanskiy 
Reviewed-by: Tariq Toukan 
Signed-off-by: Saeed Mahameed 
Signed-off-by: Sasha Levin

net/mlx5e: Rename hw_modify to preactivate

2020-04-21T07:06:42+00:00

[ Upstream commit dca147b3dce5abb5284ff747211960fd2db5ec2e ]

mlx5e_safe_switch_channels accepts a callback to be called before
activating new channels. It is intended to configure some hardware
parameters in cases where channels are recreated because some
configuration has changed.

Recently, this callback has started being used to update the driver's
internal MLX5E_STATE_XDP_OPEN flag, and the following patches also
intend to use this callback for software preparations. This patch
renames the hw_modify callback to preactivate, so that the name fits
better.

Signed-off-by: Maxim Mikityanskiy 
Reviewed-by: Tariq Toukan 
Signed-off-by: Saeed Mahameed 
Signed-off-by: Sasha Levin

net/mlx5e: Encapsulate updating netdev queues into a function

2020-04-21T07:06:42+00:00

[ Upstream commit c2c95271f9f39ea9b34db2301b3b6c5105cdb447 ]

As a preparation for one of the following commits, create a function to
encapsulate the code that notifies the kernel about the new amount of
RX and TX queues. The code will be called multiple times in the next
commit.

Signed-off-by: Maxim Mikityanskiy 
Reviewed-by: Tariq Toukan 
Signed-off-by: Saeed Mahameed 
Signed-off-by: Sasha Levin