Currently calls to:
gpiod_direction_output_raw()
gpiod_set_raw_value()
gpiod_set_raw_array_value()
gpiod_set_raw_value_cansleep()
gpiod_set_raw_array_value_cansleep()

Respect that we do not want to invert the value written, but will
still apply special open drain/open source semantics if the line has
an open drain/open source flag.

It also forbids us from driving an output marked as an interrupt
line.

This does not fit with the function name and expected semantics. In
the w1 host driver (for example) we need to handle a line as open drain
but sometimes force it to pull up, which means we should be able to
use the gpiod_set_raw_value() for this, but it currently does not
work.

There are also use cases where users actually want to drive a line
used by an interrupt. This is what they should be expected to use
the *raw* accessors for.

I have looked over the current users of this API and they do not seem
to be using the *raw* accessors with open drain or open source so let's
augment this behaviour before we have users expecting the inconsistent
semantic.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The arbitrarily marking of a function with _ or __ is taking to mean
"perform some inner core of the caller" or something like that. At other
times, this syntax has a totally different meaning.

I don't like this since it is unambious and unhelpful to people reading
the code, so replace it with _commit() suffixes.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This reverts commit 108d23e3.
It turns out this causes a regression on the OMAP, Marvell
and Renesas.
Reported-by: NTony Lindgren <tony@atomide.com>
Reported-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reported-by: NJacopo Mondi <jacopo@jmondi.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When converting legacy board to use gpiod API() there might be several
lookup tables in board file, let's provide a way to register them all at
once.
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Some kerneldoc has become stale or wasn't quite correct from the outset.
Fix up the most serious issues to silence warnings when building the
documentation.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.
Signed-off-by: NRob Herring <robh@kernel.org>
Cc: Tien Hock Loh <thloh@altera.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com>
Cc: linux-gpio@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Acked-by: NGregory Fong <gregory.0xf0@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Now IRQ mappings are always created for all (allowed) GPIOs in gpiochip in
gpiochip_irqchip_add_key() which goes against the idea of SPARSE_IRQ and,
as result, leads to:
 - increasing of memory consumption for IRQ descriptors most of which will
never ever be used (espessially on platform with a high number of GPIOs).
(sizeof(struct irq_desc) == 256 on my tested platforms)
 - imposibility to use GPIO irqchip APIs by gpio drivers when HW implements
GPIO IRQ functionality as IRQ crossbar/router which has only limited
number of IRQ outputs (example from [1], all GPIOs can be mapped on only 8
IRQs).

Hence, remove static IRQ mapping code from gpiochip_irqchip_add_key() and
instead replace irq_find_mapping() with irq_create_mapping() in
gpiochip_to_irq(). Also add additional gpiochip_irqchip_irq_valid() calls
in gpiochip_to_irq() and gpiochip_irq_map().

After this change gpio2irq mapping will happen the following way when GPIO
irqchip APIs are used by gpio driver:
 - IRQ mappings will be created statically if driver passes first_irq>0
vlaue in gpiochip_irqchip_add_key().
 - IRQ mappings will be created dynamically from gpio_to_irq() or
of_irq_get().

Tested on am335x-evm and dra72-evm-revc.
- dra72-evm-revc: number of created irq mappings decreased from 402 -> 135
  Mem savings 267*256 = 68352 (66kB)
- am335x-evm: number of created irq mappings decreased from 188 -> 63
  Mem savings 125*256 = 32000 (31kB)

[1] https://lkml.org/lkml/2017/6/15/428Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Before querying a GPIO to determine its direction, the GPIO should be
formally requested.  This allows the GPIO driver to block access to
unavailable GPIOs, which makes it easier for some drivers to support
sparse GPIO maps.
Signed-off-by: NTimur Tabi <timur@codeaurora.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The previous fix for filtering out of unwatched events was not entirely
correct. Instead of skipping the events we don't want, they are now
interpreted as events with opposing edge.

In order to fix it: always read the GPIO line value on interrupt and
only emit the event if it corresponds with the event type we requested.

Cc: stable@vger.kernel.org
Fixes: ad537b82 ("gpiolib: fix filtering out unwanted events")
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

GPIOEVENT_REQUEST_BOTH_EDGES is not a single flag, but a binary OR of
GPIOEVENT_REQUEST_RISING_EDGE and GPIOEVENT_REQUEST_FALLING_EDGE.

The expression 'le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES' we'll get
evaluated to true even if only one event type was requested.

Fix it by checking both RISING & FALLING flags explicitly.

Cc: stable@vger.kernel.org
Fixes: 61f922db ("gpio: userspace ABI for reading GPIO line events")
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This was left behind by a cleanup patch:

drivers/gpio/gpiolib.c: In function 'gpiochip_irqchip_init_valid_mask':
drivers/gpio/gpiolib.c:1474:6: error: unused variable 'i' [-Werror=unused-variable]

Fixes: 923a654c ("gpiolib: Re-use bitmap_fill() instead of open coded loop")
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Reported-by: NColin King <colin.king@canonical.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Re-use bitmap_fill() instead of open coded loop for setting an area of
bits in a bitmap.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This allows ACPI GPIO code to modify flags based on
ACPI GpioIo() / GpioInt() resources.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This is preparatory patch for enabling GPIO ACPI to configure a pin
accordingly.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add new flags to allow users to specify that they are not concerned with
the status of GPIOs whilst in a sleep/low power state.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

For hot-pluggable devices adding GPIOs dynamically we need to
assemble and add the gpio lookup tables at probe time in modules,
so that requesting these GPIOs in attached drivers can work.
Export lookup table functions for modules.
Signed-off-by: NAnatolij Gustschin <agust@denx.de>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Interrupt numbers are never negative, zero serves as the special invalid
value.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Currently, the GPIO interface is said to Open Drain if it is Single
Ended and active LOW. Similarly, it is said as Open Source if it is
Single Ended and active HIGH.

The active HIGH/LOW is used in the interface for setting the pin
state to HIGH or LOW when enabling/disabling the interface.

In Open Drain interface, pin is set to HIGH by putting pin in
high impedance and LOW by driving to the LOW.

In Open Source interface, pin is set to HIGH by driving pin to
HIGH and set to LOW by putting pin in high impedance.

With above, the Open Drain/Source is unrelated to the active LOW/HIGH
in interface. There is interface where the enable/disable of interface
is ether active LOW or HIGH but it is Open Drain type.

Hence decouple the Open Drain with Single Ended + Active LOW and
Open Source with Single Ended + Active HIGH.

Adding different flag for the Open Drain/Open Source which is valid
only when Single ended flag is enabled.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Replace the open coded registration of the cdev and dev with the
new device_add_cdev() helper. The helper replaces a common pattern by
taking the proper reference against the parent device and adding both
the cdev and the device.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It's unusual to have error checking like (ret <= 0) in cases when
counting GPIO resources. In case when it's mandatory we propagate the
error (-ENOENT), otherwise we don't use the result.

This makes consistent behaviour across all possible variants called in
gpiod_count().
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Remove extra 'l' in "successfull".
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

devm_fwnode_get_gpiod_from_child() currently allows GPIO users to
request a GPIO that is defined in a child fwnode instead of directly in
the device fwnode.
Extend this API by adding the devm_fwnode_get_index_gpiod_from_child()
helper which does the same except you can also specify an index in case
the 'xx-gpios' property describe several GPIOs.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

"if (!x) WARN_ON(x)" can never trigger.
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Currently we already have two pin configuration related callbacks
available for GPIO chips .set_single_ended() and .set_debounce(). In
future we expect to have even more, which does not scale well if we need
to add yet another callback to the GPIO chip structure for each possible
configuration parameter.

Better solution is to reuse what we already have available in the
generic pinconf.

To support this, we introduce a new .set_config() callback for GPIO
chips. The callback takes a single packed pin configuration value as
parameter. This can then be extended easily beyond what is currently
supported by just adding new types to the generic pinconf enum.

If the GPIO driver is backed up by a pinctrl driver the GPIO driver can
just assign gpiochip_generic_config() (introduced in this patch) to
.set_config and that will take care configuration requests are directed
to the pinctrl driver.

We then convert the existing drivers over .set_config() and finally
remove the .set_single_ended() and .set_debounce() callbacks.
Suggested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Currently all users of fwnode_get_named_gpiod() have no way to
specify a label for the GPIO. So GPIOs listed in debugfs are shown
with label "?". With this change a proper label is used.

Also adjust all users so they can pass a label, properly retrieved
from device tree properties.
Signed-off-by: NAlexander Stein <alexander.stein@systec-electronic.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJacek Anaszewski <jacek.anaszewski@gmail.com>
Acked-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Make fwnode_get_named_gpiod() consistent with the rest of
gpiod_get() like API, i.e. configure GPIO pin immediately after
request.

Besides obvious clean up it will help to configure pins based
on firmware provided resources.
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The helper function for adding a GPIO chip compiles in a lockdep
key for debugging, the same key is needed for nested chips as
well.

The macro construction is unreadable, replace this with two
static inlines instead.

The _gpiochip_irqchip_add prefixed function is not helpful,
rename it with gpiochip_irqchip_add_key() that tell us what the
function is actually doing.

Fixes: d245b3f9 ("gpio: simplify adding threaded interrupts")
Cc: Roger Quadros <rogerq@ti.com>
Reported-by: NClemens Gruber <clemens.gruber@pqgruber.com>
Reported-by: NRoger Quadros <rogerq@ti.com>
Reported-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NClemens Gruber <clemens.gruber@pqgruber.com>
Tested-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

container_of() does pointer math on the pointer that's passed in.
If it were to return a NULL pointer the value passed in would
need to be perfectly offset from 0 to make that so. Remove these
checks because they don't make sense.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The macro for_each_set_bit() effectively looks up to the next
set bit in array of bits.

Instead of open coding that switch to for_each_set_bit() in
gpio_chip_set_multiple().

While here, make gpio_chip_set_multiple() non-destructive
against its parameters. We are safe since all callers, i.e.
gpiod_set_array_value_complex(), handle that already.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When removing a gpiochip that uses GPIO hogging (e.g. by unloading the
chip's DT overlay), a warning is printed:

    gpio gpiochip8: REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED

This happens because gpiochip_free_hogs() is called after the gdev->chip
pointer is reset to NULL. Hence __gpiod_free() cannot determine the
chip in use, and cannot clear flags nor call the optional chip-specific
.free() callback.

Move the call to gpiochip_free_hogs() up to fix this.

Cc: stable@vger.kernel.org
Fixes: ff2b1359 ("gpio: make the gpiochip a real device")
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The GPIO chardev is used for management tasks (allocating line and event
handles) and does neither support read() nor write() operations. Hence it
does not make much sense to allow seek operations.

Currently the chardev uses noop_llseek() for its seek implementation. This
function does not move the pointer and simply returns the current position
(always 0 for the GPIO chardev). noop_llseek() is primarily meant for
devices that can not support seek, but where there might be a user that
depends on the seek() operation succeeding. For newly added devices that
can not support seek operations it is recommended to use no_llseek(), which
will return an error. For more information see commit 6038f373
("llseek: automatically add .llseek fop").

Unfortunately this was overlooked when the GPIO chardev ABI was introduced.
But it is highly unlikely that since then userspace applications have
appeared that rely on being able to perform non-failing seek operations on
a GPIO chardev file descriptor. So it should be safe to change from
noop_llseel() to no_seek(). Also use nonseekable_open() in the chardev
open() callback to clear the FMODE_SEEK, FMODE_PREAD and FMODE_PWRITE flags
from the file. Neither of these should be set on a file that does not
support seek operations.

Cc: stable@vger.kernel.org
Fixes: 3c702e99 ("gpio: add a userspace chardev ABI for GPIOs")
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This tries to simplify the use of CONFIG_GPIOLIB_IRQCHIP when
using threaded interrupts: add a new call
gpiochip_irqchip_add_nested() to indicate that we're dealing
with a nested rather than a chained irqchip, then create a
separate gpiochip_set_nested_irqchip() to mirror
the gpiochip_set_chained_irqchip() call to connect the
parent and child interrupts.

In the nested case gpiochip_set_nested_irqchip() does nothing
more than call irq_set_parent() on each valid child interrupt,
which has little semantic effect in the kernel, but this is
probably still formally correct.

Update all drivers using nested interrupts to use
gpiochip_irqchip_add_nested() so we can now see clearly
which these users are.

The DLN2 driver can drop its specific hack with
.irq_not_threaded as we now recognize whether a chip is
threaded or not from its use of gpiochip_irqchip_add_nested()
signature rather than from inspecting .can_sleep.

We rename the .irq_parent to .irq_chained_parent since this
parent IRQ is only really kept around for the chained
interrupt handlers.

Cc: Lars Poeschel <poeschel@lemonage.de>
Cc: Octavian Purdila <octavian.purdila@intel.com>
Cc: Daniel Baluta <daniel.baluta@intel.com>
Cc: Bin Gao <bin.gao@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>
Cc: Semen Protsenko <semen.protsenko@globallogic.com>
Cc: Alexander Stein <alexander.stein@systec-electronic.com>
Cc: Phil Reid <preid@electromag.com.au>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When a GPIO line is marked as used for an interrupt, it is
helpful to set the label to "interrupt" so we know what is
going on when inspecting the lines.

If a GPIO is already properly named by gpiod_get*() we don't
need to do this. It only happens when a line is used from
the irqchip side of a GPIO driver without communicating
with the GPIO side, such as when gpiochip is used as interrupt
provider in the device tree.

If the line is still marked as used by "interrupt" when we
unmark it as used by an interrupt, also remove this label
from the descriptor.

Also shape up the code around unmarking IRQ lines.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

I saw weird values != [0,1] being passed down to drivers
in their .set_direction_output() callbacks. Go over the
gpiolib and make sure to hammer it to [0,1] before hitting
the driver to avoid undesired side effects.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When locking a GPIO line as IRQ, we go to lengths to
double-check that the line is really set as input before
marking it as used for IRQ. This is not good on GPIO chips
that can sleep, because this function is called in IRQ-safe
context. Just skip this if it can't be checked quickly.

Currently this happens on sleeping expanders such as STMPE
or TC3589x:

BUG: scheduling while atomic: swapper/1/0x00000002
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.9.0-rc1+ #38
Hardware name: Nomadik STn8815
[<c000f2e0>] (unwind_backtrace) from [<c000d244>] (show_stack+0x10/0x14)
[<c000d244>] (show_stack) from [<c0037b78>] (__schedule_bug+0x54/0x80)
[<c0037b78>] (__schedule_bug) from [<c042df14>] (__schedule+0x3a0/0x460)
[<c042df14>] (__schedule) from [<c042e028>] (schedule+0x54/0xb8)
(...)

This patch fixes that problem and relies on the direction
read from the chip when it was added.

Cc: stable@vger.kernel.org
Fixes: 9c10280d ("gpio: flush direction status in gpiochip_lock_as_irq()")
Cc: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When allocating a new line handle or event a file is allocated that it is
associated to. The file is attached to a file descriptor of the current
process and the file descriptor is returned to userspace using
copy_to_user(). If this copy operation fails the line handle or event
allocation is aborted, all acquired resources are freed and an error is
returned.

But the file struct is not freed and left attached to the userspace
application and even though the file descriptor number was not copied it is
trivial to guess. If a userspace application performs a IOCTL on such a
left over file descriptor it will trigger a use-after-free and if the file
descriptor is closed (latest when the application exits) a double-free is
triggered.

anon_inode_getfd() performs 3 tasks, allocate a file struct, allocate a
file descriptor for the current process and install the file struct in the
file descriptor. As soon as the file struct is installed in the file
descriptor it is accessible by userspace (even if the IOCTL itself hasn't
completed yet), this means uninstalling the fd on the error path is not an
option, since userspace might already got a reference to the file.

Instead anon_inode_getfd() needs to be broken into its individual steps.
The allocation of the file struct and file descriptor is done first, then
the copy_to_user() is executed and only if it succeeds the file is
installed.

Since the file struct is reference counted it can not be just freed, but
its reference needs to be dropped, which will also call the release()
callback, which will free the state attached to the file. So in this case
the normal error cleanup path should not be taken.

Cc: stable@vger.kernel.org
Fixes: d932cd49 ("gpio: free handles in fringe cases")
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The GPIO_GET_LINEEVENT_IOCTL currently ignores unknown or undefined
linehandle and lineevent flags. From a backwards and forwards compatibility
viewpoint it is highly desirable to reject unknown flags though.

On one hand an application that is using newer flags and is running on
an older kernel has no way to detect if the new flags were handled
correctly if they are silently discarded.

On the other hand an application that (accidentally) passes undefined flags
will run fine on an older kernel, but may break on a newer kernel when
these flags get defined.

Ensure that requests that have undefined flags set are rejected with an
error, rather than silently discarding the undefined flags.

Cc: stable@vger.kernel.org
Fixes: 61f922db ("gpio: userspace ABI for reading GPIO line events")
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The GPIO_GET_LINEHANDLE_IOCTL currently ignores unknown or undefined
linehandle flags. From a backwards and forwards compatibility viewpoint it
is highly desirable to reject unknown flags though.

On one hand an application that is using newer flags and is running on
an older kernel has no way to detect if the new flags were handled
correctly if they are silently discarded.

On the other hand an application that (accidentally) passes undefined flags
will run fine on an older kernel, but may break on a newer kernel when
these flags get defined.

Ensure that requests that have undefined flags set are rejected with an
error, rather than silently discarding the undefined flags.

Cc: stable@vger.kernel.org
Fixes: d7c51b47 ("gpio: userspace ABI for reading/writing GPIO lines")
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The GPIOHANDLE_GET_LINE_VALUES_IOCTL handler allocates a gpiohandle_data
struct on the stack and then passes it to copy_to_user(). But depending on
the number of requested line handles the struct is only partially
initialized.

This exposes the previous, potentially sensitive, stack content to the
issuing userspace application. To avoid this make sure that the struct is
fully initialized.

Cc: stable@vger.kernel.org
Fixes: d7c51b47 ("gpio: userspace ABI for reading/writing GPIO lines")
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The line offset that is used as an index into the descs array is provided
by userspace and might go beyond the bounds of the array. If that happens
undefined behavior will occur.

Make sure that the offset is within the bounds of the desc array and reject
any requests that specify a value outside of it.

Cc: stable@vger.kernel.org
Fixes: 61f922db ("gpio: userspace ABI for reading GPIO line events")
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>