linux-stable.git/drivers/watchdog, branch linux-4.15.y

watchdog: dw_wdt: add stop watchdog operation

2018-04-12T10:31:03+00:00

[ Upstream commit 1bfe8889380890efe4943d125124f5a7b48571b0 ]

The only way of stopping the watchdog is by resetting it.
Add the watchdog op for stopping the device and reset if
a reset line is provided.

At same time WDOG_HW_RUNNING should be remove from dw_wdt_start.
As commented by Guenter Roeck:
dw_wdt sets WDOG_HW_RUNNING in its open function. Result is
that the kref_get() in watchdog_open() won't be executed. But then
kref_put() in close will be called since the watchdog now does stop.
This causes the imbalance.

Signed-off-by: Oleksij Rempel 
Cc: Wim Van Sebroeck 
Cc: Guenter Roeck 
Cc: linux-watchdog@vger.kernel.org
Reviewed-by: Guenter Roeck 
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ACPI / watchdog: Fix off-by-one error at resource assignment

2018-03-28T16:23:00+00:00

commit b1abf6fc49829d89660c961fafe3f90f3d843c55 upstream.

The resource allocation in WDAT watchdog has off-one-by error, it sets
one byte more than the actual end address.  This may eventually lead
to unexpected resource conflicts.

Fixes: 058dfc767008 (ACPI / watchdog: Add support for WDAT hardware watchdog)
Cc: 4.9+  # 4.9+
Signed-off-by: Takashi Iwai 
Acked-by: Mika Westerberg 
Acked-by: Guenter Roeck 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

watchdog: Fix kref imbalance seen if handle_boot_enabled=0

2018-03-24T10:02:46+00:00

[ Upstream commit 914d65f3f013ba2556c7beec5d3baac7b3292504 ]

If handle_boot_enabled is set to 0, the watchdog driver module use
counter will not be increased and kref_get() will not be called when
registering the watchdog. Subsequently, on open, this does not happen
either because the code believes that it was already done because the
hardware watchdog is marked as running.

We could introduce a state variable to indicate this state, but let's
just increase the module use counter and call kref_get() unconditionally
if the hardware watchdog is running when a driver is registering itself
to keep the code simple.

Fixes: 2501b015313fe ("watchdog: core: add option to avoid early ...")
Cc: Sebastian Reichel 
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

watchdog: Fix potential kref imbalance when opening watchdog

2018-03-24T10:02:46+00:00

[ Upstream commit 4bcd615fad6adddc68b058d498b30a9e0e0db77a ]

If a watchdog driver's open function sets WDOG_HW_RUNNING with the
expectation that the watchdog can not be stopped, but then stops the
watchdog anyway in its stop function, kref_get() wil not be called in
watchdog_open(). If the watchdog then stops on close, WDOG_HW_RUNNING
will be cleared and kref_put() will be called, causing a kref imbalance.
As result the character device data structure will be released, which in
turn will cause the system to crash on the next call to watchdog_open().

Fixes: ee142889e32f5 ("watchdog: Introduce WDOG_HW_RUNNING flag")
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

watchdog: hpwdt: Remove legacy NMI sourcing.

2018-03-15T09:56:56+00:00

commit 2b3d89b402b085b08498e896c65267a145bed486 upstream.

Gen8 and prior Proliant systems supported the "CRU" interface
to firmware.  This interfaces allows linux to "call back" into firmware
to source the cause of an NMI.  This feature isn't fully utilized
as the actual source of the NMI isn't printed, the driver only
indicates that the source couldn't be determined when the call
fails.

With the advent of Gen9, iCRU replaces the CRU. The call back
feature is no longer available in firmware.  To be compatible and
not attempt to call back into firmware on system not supporting CRU,
the SMBIOS table is consulted to determine if it is safe to
make the call back or not.

This results in about half of the driver code being devoted
to either making CRU calls or determing if it is safe to make
CRU calls.  As noted, the driver isn't really using the results of
the CRU calls.

Furthermore, as a consequence of the Spectre security issue, the
BIOS/EFI calls are being wrapped into Spectre-disabling section.
Removing the call back in hpwdt_pretimeout assists in this effort.

As the CRU sourcing of the NMI isn't required for handling the
NMI and there are security concerns with making the call back, remove
the legacy (pre Gen9) NMI sourcing and the DMI code to determine if
the system had the CRU interface.

Signed-off-by: Jerry Hoemann 
Acked-by: Ingo Molnar 
Reviewed-by: Guenter Roeck 
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Greg Kroah-Hartman

watchdog: hpwdt: fix unused variable warning

2018-03-15T09:56:56+00:00

commit aeebc6ba88ba3758ad95467ff6191fabf2074c13 upstream.

The new hpwdt_my_nmi() function is used conditionally, which produces
a harmless warning in some configurations:

drivers/watchdog/hpwdt.c:478:12: error: 'hpwdt_my_nmi' defined but not used [-Werror=unused-function]

This moves it inside of the #ifdef that protects its caller, to silence
the warning.

Fixes: 621174a92851 ("watchdog: hpwdt: Check source of NMI")
Signed-off-by: Arnd Bergmann 
Reviewed-by: Jerry Hoemann 
Reviewed-by: Guenter Roeck 
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Greg Kroah-Hartman

watchdog: hpwdt: Check source of NMI

2018-03-15T09:56:56+00:00

commit 838534e50e2e5c1e644e30ab6cb28da88eb31368 upstream.

Do not claim the NMI (i.e. return NMI_DONE) if the source of
the NMI isn't the iLO watchdog or debug.

Signed-off-by: Jerry Hoemann 
Reviewed-by: Guenter Roeck 
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Greg Kroah-Hartman

watchdog: hpwdt: SMBIOS check

2018-03-15T09:56:55+00:00

commit c42cbe41727a138905a28f8e0b00c147be77ee93 upstream.

This corrects:
commit cce78da76601 ("watchdog: hpwdt: Add check for UEFI bits")

The test on HPE SMBIOS extension type 219 record "Misc Features"
bits for UEFI support is incorrect.  The definition of the Misc Features
bits in the HPE SMBIOS OEM Extensions specification (and related
firmware) was changed to use a different pair of bits to
represent UEFI supported.  Howerver, a corresponding change
to Linux was missed.

Current code/platform work because the iCRU test is working.
But purpose of cce78da766 is to ensure correct functionality
on future systems where iCRU isn't supported.

Signed-off-by: Jerry Hoemann 
Reviewed-by: Guenter Roeck 
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Greg Kroah-Hartman

watchdog: imx2_wdt: restore previous timeout after suspend+resume

2018-02-16T19:06:52+00:00

commit 0be267255cef64e1c58475baa7b25568355a3816 upstream.

When the watchdog device is suspended, its timeout is set to the maximum
value. During resume, the previously set timeout should be restored.
This does not work at the moment.

The suspend function calls

imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);

and resume reverts this by calling

imx2_wdt_set_timeout(wdog, wdog->timeout);

However, imx2_wdt_set_timeout() updates wdog->timeout. Therefore,
wdog->timeout is set to IMX2_WDT_MAX_TIME when we enter the resume
function.

Fix this by adding a new function __imx2_wdt_set_timeout() which
only updates the hardware settings. imx2_wdt_set_timeout() now calls
__imx2_wdt_set_timeout() and then saves the new timeout to
wdog->timeout.

During suspend, we call __imx2_wdt_set_timeout() directly so that
wdog->timeout won't be updated and we can restore the previous value
during resume. This approach makes wdog->timeout different from the
actual setting in the hardware which is usually not a good thing.
However, the two differ only while we're suspended and no kernel code is
running, so it should be ok in this case.

Signed-off-by: Martin Kaiser 
Reviewed-by: Guenter Roeck 
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Greg Kroah-Hartman

watchdog: gpio_wdt: set WDOG_HW_RUNNING in gpio_wdt_stop

2018-02-16T19:06:31+00:00

commit bc137dfdbec27c0ec5731a89002daded4a4aa1ea upstream.

The first patch above (https://patchwork.kernel.org/patch/9970181/)
makes the oops go away, but it just papers over the problem. The real
problem is that the watchdog core clears WDOG_HW_RUNNING in
watchdog_stop, and the gpio driver fails to set it in its stop
function when it doesn't actually stop it. This means that the core
doesn't know that it now has responsibility for petting the device, in
turn causing the device to reset the system (I hadn't noticed this
because the board I'm working on has that reset logic disabled).

How about this (other drivers may of course have the same problem, I
haven't checked). One might say that ->stop should return an error
when the device can't be stopped, but OTOH this brings parity between
a device without a ->stop method and a GPIO wd that has always-running
set. IOW, I think ->stop should only return an error when an actual
attempt to stop the hardware failed.

From: Rasmus Villemoes 

The watchdog framework clears WDOG_HW_RUNNING before calling
->stop. If the driver is unable to stop the device, it is supposed to
set that bit again so that the watchdog core takes care of sending
heart-beats while the device is not open from user-space. Update the
gpio_wdt driver to honour that contract (and get rid of the redundant
clearing of WDOG_HW_RUNNING).

Fixes: 3c10bbde10 ("watchdog: core: Clear WDOG_HW_RUNNING before calling the stop function")
Signed-off-by: Rasmus Villemoes 
Reviewed-by: Guenter Roeck 
Signed-off-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck 
Signed-off-by: Greg Kroah-Hartman