linux-stable.git/arch/powerpc/kernel/eeh_driver.c, branch linux-4.8.y

powerpc/eeh: Fix deadlock when PE frozen state can't be cleared

2016-12-15T16:50:34+00:00

commit 409bf7f8a02ef88db5a0f2cdcf9489914f4b8508 upstream.

In eeh_reset_device(), we take the pci_rescan_remove_lock immediately after
after we call eeh_reset_pe() to reset the PCI controller. We then call
eeh_clear_pe_frozen_state(), which can return an error. In this case, we
bail out of eeh_reset_device() without calling pci_unlock_rescan_remove().

Add a call to pci_unlock_rescan_remove() in the eeh_clear_pe_frozen_state()
error path so that we don't cause a deadlock later on.

Reported-by: Pradipta Ghosh 
Fixes: 78954700631f ("powerpc/eeh: Avoid I/O access during PE reset")
Signed-off-by: Andrew Donnellan 
Acked-by: Russell Currey 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/eeh: Null check uses of eeh_pe_bus_get

2016-10-28T07:45:21+00:00

commit 04fec21c06e35b169a83e75a84a015ab4606bf5e upstream.

eeh_pe_bus_get() can return NULL if a PCI bus isn't found for a given PE.
Some callers don't check this, and can cause a null pointer dereference
under certain circumstances.

Fix this by checking NULL everywhere eeh_pe_bus_get() is called.

Fixes: 8a6b1bc70dbb ("powerpc/eeh: EEH core to handle special event")
Signed-off-by: Russell Currey 
Reviewed-by: Andrew Donnellan 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'powerpc-4.7-5' into next

2016-07-15T04:57:47+00:00

Pull in the fixes we sent during 4.7, we have code we want to merge into
next that depends on some of them.

powerpc/eeh: Fix wrong argument passed to eeh_rmv_device()

2016-06-28T10:47:49+00:00

When calling eeh_rmv_device() in eeh_reset_device() for partial hotplug
case, @rmv_data instead of its address is the proper argument.
Otherwise, the stack frame is corrupted when writing to
@rmv_data (actually its address) in eeh_rmv_device(). It results in
kernel crash as observed.

This fixes the issue by passing @rmv_data, not its address to
eeh_rmv_device() in eeh_reset_device().

Fixes: 67086e32b564 ("powerpc/eeh: powerpc/eeh: Support error recovery for VF PE")
Reported-by: Pridhiviraj Paidipeddi 
Signed-off-by: Gavin Shan 
Signed-off-by: Michael Ellerman

powerpc/eeh: Fix invalid cached PE primary bus

2016-06-17T09:51:47+00:00

The PE primary bus cannot be got from its child devices when having
full hotplug in error recovery. The PE primary bus is cached, which
is done in commit <05ba75f84864> ("powerpc/eeh: Fix stale cached primary
bus"). In eeh_reset_device(), the flag (EEH_PE_PRI_BUS) is cleared
before the PCI hot remove. eeh_pe_bus_get() then returns NULL as the
PE primary bus in pnv_eeh_reset() and it crashes the kernel eventually.

This fixes the issue by clearing the flag (EEH_PE_PRI_BUS) before the
PCI hot add. With it, the PowerNV EEH reset backend (pnv_eeh_reset())
can get valid PE primary bus through eeh_pe_bus_get().

Fixes: 67086e32b564 ("powerpc/eeh: powerpc/eeh: Support error recovery for VF PE")
Reported-by: Pridhiviraj Paidipeddi 
Signed-off-by: Gavin Shan 
Signed-off-by: Michael Ellerman

powerpc: Various typo fixes

2016-06-14T03:58:26+00:00

Signed-off-by: Andrea Gelmini 
Signed-off-by: Michael Ellerman

powerpc/eeh: Ignore handlers in eeh_pe_reset_and_recover()

2016-05-12T09:52:20+00:00

The function eeh_pe_reset_and_recover() is used to recover EEH
error when the passthrough device are transferred to guest and
backwards, meaning the device's driver is vfio-pci or none. In
both cases, the handlers triggered by eeh_report_reset() and
eeh_report_resume() shouldn't be called.

This ignores the error handlers from eeh_report_reset() and
eeh_report_resume().

Signed-off-by: Gavin Shan 
Reviewed-by: Russell Currey 
Signed-off-by: Michael Ellerman

powerpc/eeh: Restore initial state in eeh_pe_reset_and_recover()

2016-05-12T09:52:20+00:00

The function eeh_pe_reset_and_recover() is used to recover EEH
error when the passthrou device are transferred to guest and
backwards. The content in the device's config space will be lost
on PE reset issued in the middle of the recovery. The function
saves/restores it before/after the reset. However, config access
to some adapters like Broadcom BCM5719 at this point will causes
fenced PHB. The config space is always blocked and we save 0xFF's
that are restored at late point. The memory BARs are totally
corrupted, causing another EEH error upon access to one of the
memory BARs.

This restores the config space on those adapters like BCM5719
from the content saved to the EEH device when it's populated,
to resolve above issue.

Fixes: 5cfb20b9 ("powerpc/eeh: Emulate EEH recovery for VFIO devices")
Cc: stable@vger.kernel.org #v3.18+
Signed-off-by: Gavin Shan 
Reviewed-by: Russell Currey 
Signed-off-by: Michael Ellerman

powerpc/eeh: Don't report error in eeh_pe_reset_and_recover()

2016-05-12T09:52:20+00:00

The function eeh_pe_reset_and_recover() is used to recover EEH
error when the passthrough device are transferred to guest and
backwards, meaning the device's driver is vfio-pci or none.
When the driver is vfio-pci that provides error_detected() error
handler only, the handler simply stops the guest and it's not
expected behaviour. On the other hand, no error handlers will
be called if we don't have a bound driver.

This ignores the error handler in eeh_pe_reset_and_recover()
that reports the error to device driver to avoid the exceptional
behaviour.

Fixes: 5cfb20b9 ("powerpc/eeh: Emulate EEH recovery for VFIO devices")
Cc: stable@vger.kernel.org #v3.18+
Signed-off-by: Gavin Shan 
Reviewed-by: Russell Currey 
Signed-off-by: Michael Ellerman

powerpc/pci: Rename pcibios_{add, remove}_pci_devices()

2016-05-11T11:54:23+00:00

This renames pcibios_{add,remove}_pci_devices() to avoid conflicts
with names of the weak functions in PCI subsystem, which have the
prefix "pcibios". No logical changes introduced.

Signed-off-by: Gavin Shan 
Reviewed-By: Alistair Popple 
Reviewed-by: Andrew Donnellan 
Reviewed-by: Alexey Kardashevskiy 
Signed-off-by: Michael Ellerman