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path: root/drivers/gpio/gpiolib-cdev.c
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2024-09-30gpiolib: cdev: Ignore reconfiguration without directionKent Gibson
commit b440396387418fe2feaacd41ca16080e7a8bc9ad upstream. linereq_set_config() behaves badly when direction is not set. The configuration validation is borrowed from linereq_create(), where, to verify the intent of the user, the direction must be set to in order to effect a change to the electrical configuration of a line. But, when applied to reconfiguration, that validation does not allow for the unset direction case, making it possible to clear flags set previously without specifying the line direction. Adding to the inconsistency, those changes are not immediately applied by linereq_set_config(), but will take effect when the line value is next get or set. For example, by requesting a configuration with no flags set, an output line with GPIO_V2_LINE_FLAG_ACTIVE_LOW and GPIO_V2_LINE_FLAG_OPEN_DRAIN set could have those flags cleared, inverting the sense of the line and changing the line drive to push-pull on the next line value set. Skip the reconfiguration of lines for which the direction is not set, and only reconfigure the lines for which direction is set. Fixes: a54756cb24ea ("gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL") Signed-off-by: Kent Gibson <warthog618@gmail.com> Link: https://lore.kernel.org/r/20240626052925.174272-3-warthog618@gmail.com Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-05gpiolib: cdev: Disallow reconfiguration without direction (uAPI v1)Kent Gibson
[ Upstream commit 9919cce62f68e6ab68dc2a975b5dc670f8ca7d40 ] linehandle_set_config() behaves badly when direction is not set. The configuration validation is borrowed from linehandle_create(), where, to verify the intent of the user, the direction must be set to in order to effect a change to the electrical configuration of a line. But, when applied to reconfiguration, that validation does not allow for the unset direction case, making it possible to clear flags set previously without specifying the line direction. Adding to the inconsistency, those changes are not immediately applied by linehandle_set_config(), but will take effect when the line value is next get or set. For example, by requesting a configuration with no flags set, an output line with GPIOHANDLE_REQUEST_ACTIVE_LOW and GPIOHANDLE_REQUEST_OPEN_DRAIN requested could have those flags cleared, inverting the sense of the line and changing the line drive to push-pull on the next line value set. Ensure the intent of the user by disallowing configurations which do not have direction set, returning an error to userspace to indicate that the configuration is invalid. And, for clarity, use lflags, a local copy of gcnf.flags, throughout when dealing with the requested flags, rather than a mixture of both. Fixes: e588bb1eae31 ("gpio: add new SET_CONFIG ioctl() to gpio chardev") Signed-off-by: Kent Gibson <warthog618@gmail.com> Link: https://lore.kernel.org/r/20240626052925.174272-2-warthog618@gmail.com Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17gpiolib: cdev: fix uninitialised kfifoKent Gibson
[ Upstream commit ee0166b637a5e376118e9659e5b4148080f1d27e ] If a line is requested with debounce, and that results in debouncing in software, and the line is subsequently reconfigured to enable edge detection then the allocation of the kfifo to contain edge events is overlooked. This results in events being written to and read from an uninitialised kfifo. Read events are returned to userspace. Initialise the kfifo in the case where the software debounce is already active. Fixes: 65cff7046406 ("gpiolib: cdev: support setting debounce") Signed-off-by: Kent Gibson <warthog618@gmail.com> Link: https://lore.kernel.org/r/20240510065342.36191-1-warthog618@gmail.com Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17gpiolib: cdev: relocate debounce_period_us from struct gpio_descKent Gibson
[ Upstream commit 9344e34e7992fec95ce6210d95ac01437dd327ab ] Store the debounce period for a requested line locally, rather than in the debounce_period_us field in the gpiolib struct gpio_desc. Add a global tree of lines containing supplemental line information to make the debounce period available to be reported by the GPIO_V2_GET_LINEINFO_IOCTL and the line change notifier. Signed-off-by: Kent Gibson <warthog618@gmail.com> Reviewed-by: Andy Shevchenko <andy@kernel.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Stable-dep-of: ee0166b637a5 ("gpiolib: cdev: fix uninitialised kfifo") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17gpiolib: cdev: Fix use after free in lineinfo_changed_notifyZhongqiu Han
[ Upstream commit 02f6b0e1ec7e0e7d059dddc893645816552039da ] The use-after-free issue occurs as follows: when the GPIO chip device file is being closed by invoking gpio_chrdev_release(), watched_lines is freed by bitmap_free(), but the unregistration of lineinfo_changed_nb notifier chain failed due to waiting write rwsem. Additionally, one of the GPIO chip's lines is also in the release process and holds the notifier chain's read rwsem. Consequently, a race condition leads to the use-after-free of watched_lines. Here is the typical stack when issue happened: [free] gpio_chrdev_release() --> bitmap_free(cdev->watched_lines) <-- freed --> blocking_notifier_chain_unregister() --> down_write(&nh->rwsem) <-- waiting rwsem --> __down_write_common() --> rwsem_down_write_slowpath() --> schedule_preempt_disabled() --> schedule() [use] st54spi_gpio_dev_release() --> gpio_free() --> gpiod_free() --> gpiod_free_commit() --> gpiod_line_state_notify() --> blocking_notifier_call_chain() --> down_read(&nh->rwsem); <-- held rwsem --> notifier_call_chain() --> lineinfo_changed_notify() --> test_bit(xxxx, cdev->watched_lines) <-- use after free The side effect of the use-after-free issue is that a GPIO line event is being generated for userspace where it shouldn't. However, since the chrdev is being closed, userspace won't have the chance to read that event anyway. To fix the issue, call the bitmap_free() function after the unregistration of lineinfo_changed_nb notifier chain. Fixes: 51c1064e82e7 ("gpiolib: add new ioctl() for monitoring changes in line info") Signed-off-by: Zhongqiu Han <quic_zhonhan@quicinc.com> Link: https://lore.kernel.org/r/20240505141156.2944912-1-quic_zhonhan@quicinc.com Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10gpio: cdev: fix missed label sanitizing in debounce_setup()Kent Gibson
commit 83092341e15d0dfee1caa8dc502f66c815ccd78a upstream. When adding sanitization of the label, the path through edge_detector_setup() that leads to debounce_setup() was overlooked. A request taking this path does not allocate a new label and the request label is freed twice when the request is released, resulting in memory corruption. Add label sanitization to debounce_setup(). Cc: stable@vger.kernel.org Fixes: b34490879baa ("gpio: cdev: sanitize the label before requesting the interrupt") Signed-off-by: Kent Gibson <warthog618@gmail.com> [Bartosz: rebased on top of the fix for empty GPIO labels] Co-developed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10gpio: cdev: check for NULL labels when sanitizing them for irqsBartosz Golaszewski
commit b3b95964590a3d756d69ea8604c856de805479ad upstream. We need to take into account that a line's consumer label may be NULL and not try to kstrdup() it in that case but rather pass the NULL pointer up the stack to the interrupt request function. To that end: let make_irq_label() return NULL as a valid return value and use ERR_PTR() instead to signal an allocation failure to callers. Cc: stable@vger.kernel.org Fixes: b34490879baa ("gpio: cdev: sanitize the label before requesting the interrupt") Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Closes: https://lore.kernel.org/lkml/20240402093534.212283-1-naresh.kamboju@linaro.org/ Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Tested-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10gpio: cdev: sanitize the label before requesting the interruptBartosz Golaszewski
commit b34490879baa847d16fc529c8ea6e6d34f004b38 upstream. When an interrupt is requested, a procfs directory is created under "/proc/irq/<irqnum>/<label>" where <label> is the string passed to one of the request_irq() variants. What follows is that the string must not contain the "/" character or the procfs mkdir operation will fail. We don't have such constraints for GPIO consumer labels which are used verbatim as interrupt labels for GPIO irqs. We must therefore sanitize the consumer string before requesting the interrupt. Let's replace all "/" with ":". Cc: stable@vger.kernel.org Reported-by: Stefan Wahren <wahrenst@gmx.net> Closes: https://lore.kernel.org/linux-gpio/39fe95cb-aa83-4b8b-8cab-63947a726754@gmx.net/ Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Kent Gibson <warthog618@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-01gpiolib: cdev: add gpio_device locking wrapper around gpio_ioctl()Kent Gibson
[ Upstream commit 1d656bd259edb89dc1d9938ec5c5389867088546 ] While the GPIO cdev gpio_ioctl() call is in progress, the kernel can call gpiochip_remove() which will set gdev->chip to NULL, after which any subsequent access will cause a crash. gpio_ioctl() was overlooked by the previous fix to protect syscalls (bdbbae241a04), so add protection for that. Fixes: bdbbae241a04 ("gpiolib: protect the GPIO device against being dropped while in use by user-space") Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines") Fixes: 3c0d9c635ae2 ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL") Fixes: aad955842d1c ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL") Signed-off-by: Kent Gibson <warthog618@gmail.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-22gpiolib: provide and use gpiod_line_state_notify()Bartosz Golaszewski
Wrap the calls to blocking_notifier_call_chain() for the line state notifier with a helper that allows us to use fewer lines of code and simpler syntax. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2023-08-21gpio: cdev: wake up lineevent poll() on device unbindBartosz Golaszewski
Add a notifier block to the lineevent_state structure and register it with the gpio_device's device notifier. Upon reception of an event, wake up the wait queue so that the user-space be forced out of poll() and need to go into a new system call which will then fail due to the chip being gone. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Kent Gibson <warthog618@gmail.com>
2023-08-21gpio: cdev: wake up linereq poll() on device unbindBartosz Golaszewski
Add a notifier block to the linereq structure and register it with the gpio_device's device notifier. Upon reception of an event, wake up the wait queue so that the user-space be forced out of poll() and need to go into a new system call which will then fail due to the chip being gone. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Kent Gibson <warthog618@gmail.com>
2023-08-21gpio: cdev: wake up chardev poll() on device unbindBartosz Golaszewski
Add a notifier block to the gpio_chardev_data structure and register it with the gpio_device's device notifier. Upon reception of an event, wake up the wait queue so that the user-space be forced out of poll() and need to go into a new system call which will then fail due to the chip being gone. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Kent Gibson <warthog618@gmail.com>
2023-08-21gpiolib: add a second blocking notifier to struct gpio_deviceBartosz Golaszewski
Add a new blocking notifier to struct gpio_device and use it to notify subscribers about the GPIO device being unregistered from the device model. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Kent Gibson <warthog618@gmail.com>
2023-08-21gpio: cdev: open-code to_gpio_chardev_data()Bartosz Golaszewski
This function is a wrapper around container_of(). It's used only once and we will have a second notifier soon, so instead of having two flavors of this helper, let's just open-code where needed. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Kent Gibson <warthog618@gmail.com>
2023-08-21gpiolib: rename the gpio_device notifierBartosz Golaszewski
Change the generic "notifier" name to "line_state_notifier" in order to reflect its purpose in preparation for adding a second notifier which will be used to notify wait queues about device unregistering. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Kent Gibson <warthog618@gmail.com>
2023-01-30gpiolib: Introduce gpio_device_get() and gpio_device_put()Andy Shevchenko
Introduce gpio_device_get() and gpio_device_put() helpers and convert existing users. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2022-12-15Merge tag 'gpio-updates-for-v6.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux Pull gpio updates from Bartosz Golaszewski: "We have a new GPIO multiplexer driver, bunch of driver updates and refactoring in the core GPIO library. GPIO core: - teach gpiolib to work with software nodes for HW description - remove ARCH_NR_GPIOS treewide as we no longer impose any limit on the number of GPIOS since the allocation became entirely dynamic - add support for HW quirks for Cirrus CS42L56 codec, Marvell NFC controller, Freescale PCIe and Ethernet controller, Himax LCDs and Mediatek mt2701 - refactor OF quirk code - some general refactoring of the OF and ACPI code, adding new helpers, minor tweaks and fixes, making fwnode usage consistent etc. GPIO uAPI: - fix an issue where the user-space can trigger a NULL-pointer dereference in the kernel by opening a device file, forcing a driver unbind and then calling one of the syscalls on the associated file descriptor New drivers: - add gpio-latch: a new GPIO multiplexer based on latches connected to other GPIOs Driver updates: - convert i2c GPIO expanders to using .probe_new() - drop the gpio-sta2x11 driver - factor out common code for the ACCES IDIO-16 family of controllers and use this new library wherever applicable in drivers - add DT support to gpio-hisi - allow building gpio-davinci as a module and increase its maxItems property - add support for a new model to gpio-pca9570 - other minor changes to various drivers" * tag 'gpio-updates-for-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (66 commits) gpio: sim: set a limit on the number of GPIOs gpiolib: protect the GPIO device against being dropped while in use by user-space gpiolib: cdev: fix NULL-pointer dereferences gpiolib: Provide to_gpio_device() helper gpiolib: Unify access to the device properties gpio: Do not include <linux/kernel.h> when not really needed. gpio: pcf857x: Convert to i2c's .probe_new() gpio: pca953x: Convert to i2c's .probe_new() gpio: max732x: Convert to i2c's .probe_new() dt-bindings: gpio: gpio-davinci: Increase maxItems in gpio-line-names gpiolib: ensure that fwnode is properly set gpio: sl28cpld: Replace irqchip mask_invert with unmask_base gpiolib: of: Use correct fwnode for DT-probed chips gpiolib: of: Drop redundant check in of_mm_gpiochip_remove() gpiolib: of: Prepare of_mm_gpiochip_add_data() for fwnode gpiolib: add support for software nodes gpiolib: consolidate GPIO lookups gpiolib: acpi: avoid leaking ACPI details into upper gpiolib layers gpiolib: acpi: teach acpi_find_gpio() to handle data-only nodes gpiolib: acpi: change acpi_find_gpio() to accept firmware node ...
2022-12-07gpiolib: protect the GPIO device against being dropped while in use by ↵Bartosz Golaszewski
user-space While any of the GPIO cdev syscalls is in progress, the kernel can call gpiochip_remove() (for instance, when a USB GPIO expander is disconnected) which will set gdev->chip to NULL after which any subsequent access will cause a crash. To avoid that: use an RW-semaphore in which the syscalls take it for reading (so that we don't needlessly prohibit the user-space from calling syscalls simultaneously) while gpiochip_remove() takes it for writing so that it can only happen once all syscalls return. Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines") Fixes: 3c0d9c635ae2 ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL") Fixes: aad955842d1c ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL") Fixes: a54756cb24ea ("gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL") Fixes: 7b8e00d98168 ("gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL") Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> [Nick: fixed a build failure with CDEV_V1 disabled] Co-authored-by: Nick Hainke <vincent@systemli.org> Reviewed-by: Kent Gibson <warthog618@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2022-12-07gpiolib: cdev: fix NULL-pointer dereferencesBartosz Golaszewski
There are several places where we can crash the kernel by requesting lines, unbinding the GPIO device, then calling any of the system calls relevant to the GPIO character device's annonymous file descriptors: ioctl(), read(), poll(). While I observed it with the GPIO simulator, it will also happen for any of the GPIO devices that can be hot-unplugged - for instance any HID GPIO expander (e.g. CP2112). This affects both v1 and v2 uAPI. This fixes it partially by checking if gdev->chip is not NULL but it doesn't entirely remedy the situation as we still have a race condition in which another thread can remove the device after the check. Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines") Fixes: 3c0d9c635ae2 ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL") Fixes: aad955842d1c ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL") Fixes: a54756cb24ea ("gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL") Fixes: 7b8e00d98168 ("gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL") Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2022-10-25gpiolib: cdev: Fix typo in kernel doc for struct lineAndy Shevchenko
When eflags has been renamed to the edflags, the kernel doc change were missed. Update kernel doc accordingly. Fixes: b1a92e94560d ("gpiolib: cdev: consolidate edge detector configuration flags") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Kent Gibson <warthog618@gmail.com>
2022-10-24gpiolib: cdev: Add missing header(s)Andy Shevchenko
Do not imply that some of the generic headers may be always included. Instead, include explicitly what we are direct user of. While at it, sort headers alphabetically. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Rewiewed-by: Kent Gibson <warthog618@gmail.com>
2022-10-08Merge tag 'gpio-updates-for-v6.1-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux Pull gpio updates from Bartosz Golaszewski: "We have a single new driver, support for a bunch of new models, improvements in drivers and core gpiolib code as well device-tree bindings changes. Summary: New driver: - IMX System Controller Unit GPIOs GPIO core: - add fdinfo output for the GPIO character device file descriptors (allows user-space to determine which processes own which GPIO lines) - improvements to OF GPIO code - new quirk for Asus UM325UAZ in gpiolib-acpi - new quirk for Freescale SPI in gpiolib-of Driver improvements: - add a new macro that reduces the amount of boilerplate code in ISA drivers and use it in relevant drivers - support two new models in gpio-pca953x - support new model in gpio-f7188x - convert more drivers to use immutable irq chips - other minor tweaks Device-tree bindings: - add DT bindings for gpio-imx-scu - convert Xilinx GPIO bindings to YAML - reference the properties from the SPI peripheral device-tree bindings instead of providing custom ones in the GPIO controller document - add parsing of GPIO hog nodes to the DT bindings for gpio-mpfs-gpio - relax the node name requirements in gpio-stmpe - add new models for gpio-rcar and gpio-pxa95xx - add a new vendor prefix: Diodes (for Diodes, Inc.) Misc: - pulled in the immutable branch from the x86 platform drivers tree including support for a new simatic board that depends on GPIO changes" * tag 'gpio-updates-for-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (36 commits) gpio: tc3589x: Make irqchip immutable gpiolib: cdev: add fdinfo output for line request file descriptors gpio: twl4030: Reorder functions which allows to drop a forward declaraion gpiolib: fix OOB access in quirk callbacks gpiolib: of: factor out conversion from OF flags gpiolib: rework quirk handling in of_find_gpio() gpiolib: of: make Freescale SPI quirk similar to all others gpiolib: of: do not ignore requested index when applying quirks gpio: ws16c48: Ensure number of irq matches number of base gpio: 104-idio-16: Ensure number of irq matches number of base gpio: 104-idi-48: Ensure number of irq matches number of base gpio: 104-dio-48e: Ensure number of irq matches number of base counter: 104-quad-8: Ensure number of irq matches number of base isa: Introduce the module_isa_driver_with_irq helper macro gpio: pca953x: Add support for PCAL6534 gpio: pca953x: Swap if statements to save later complexity gpio: pca953x: Fix pca953x_gpio_set_pull_up_down() dt-bindings: gpio: pca95xx: add entry for pcal6534 and PI4IOE5V6534Q dt-bindings: vendor-prefixes: add Diodes gpio: mt7621: Switch to use platform_get_irq() function ...
2022-09-26gpiolib: cdev: add fdinfo output for line request file descriptorsBartosz Golaszewski
Add fdinfo output for file descriptors created for user-space line requests in GPIO uAPI v2. The fdinfo file now contains the name of the GPIO chip that is the "parent" of the request as well as offsets of the lines requested. This allows user-space to parse the /proc/$PID/fdinfo entries and deduce the PID of the process that requested a specific line. Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl> Reviewed-by: Kent Gibson <warthog618@gmail.com>
2022-09-21gpiolib: cdev: Set lineevent_state::irq after IRQ register successfullyMeng Li
When running gpio test on nxp-ls1028 platform with below command gpiomon --num-events=3 --rising-edge gpiochip1 25 There will be a warning trace as below: Call trace: free_irq+0x204/0x360 lineevent_free+0x64/0x70 gpio_ioctl+0x598/0x6a0 __arm64_sys_ioctl+0xb4/0x100 invoke_syscall+0x5c/0x130 ...... el0t_64_sync+0x1a0/0x1a4 The reason of this issue is that calling request_threaded_irq() function failed, and then lineevent_free() is invoked to release the resource. Since the lineevent_state::irq was already set, so the subsequent invocation of free_irq() would trigger the above warning call trace. To fix this issue, set the lineevent_state::irq after the IRQ register successfully. Fixes: 468242724143 ("gpiolib: cdev: refactor lineevent cleanup into lineevent_free") Cc: stable@vger.kernel.org Signed-off-by: Meng Li <Meng.Li@windriver.com> Reviewed-by: Kent Gibson <warthog618@gmail.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-08-04Merge tag 'gpio-updates-for-v6.0-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux Pull gpio updates from Bartosz Golaszewski: "Here are the updates for this merge window from the GPIO subsystem. We have more lines removed than added thanks to dropping of a driver for a platform that's no longer supported. Otherwise the changes are pretty straightforward: support for some new models, various improvements to existing drivers, some tweaks to the core library code and DT bindings updates. Summary: - remove gpio-vr41xx driver as the only platform using it got dropped too - add support for suspend/resume to gpio-davinci - improvements to the GPIO character device code - add support for disabling bias for in-kernel users (up until now only user-space could set it) - drop unused devm_gpio_free() - fix a refcount issue in gpiolib OF - use device match helpers where applicable - add support for a new model to gpio-rockchip - non-functional improvements in gpio-adp5588 - improve and simplify teardown in gpio-twl4030 and gpio-ucb1400 - modernize the gpio-74xx-mmio and gpio-adnp drivers - coding style improvements in gpio-xilinx, gpio-104-idi-48 - support new model (pca9571) in gpio-pca9570 - convert the DT bindings to YAML for gpio-mvebu and update the document - don't return error codes from remove() in gpio-brcmstb - add a library for the intel 8255 PPI interface and use it in drivers - reduce using magic numbers and improve code readability in several drivers - convert DT bindings to YAML for gpio-tpic2810 - add new models to DT bindings for gpio-frl-imx - Kconfig improvements - other minor tweaks and improvements" * tag 'gpio-updates-for-v6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (52 commits) dt-bindings: gpio: fsl-imx-gpio: Add i.MXRT compatibles gpio: 74xx-mmio: Use bits instead of plain numbers for flags gpio: xilinx: add missing blank line after declarations MAINTAINERS: Update Intel 8255 GPIO driver file list gpio: gpio-mm: Implement and utilize register structures gpio: 104-idi-48: Implement and utilize register structures gpio: 104-dio-48e: Implement and utilize register structures gpio: i8255: Introduce the Intel 8255 interface library module gpio: 104-idio-16: Implement and utilize register structures gpio: ws16c48: Implement and utilize register structures gpio: remove VR41XX related gpio driver dt-bindings: gpio: add pull-disable flag gpiolib: acpi: support bias pull disable gpiolib: of: support bias pull disable gpiolib: add support for bias pull disable gpio: 74xx-mmio: use bits.h macros for all masks gpio: 74xx-mmio: Check MMIO_74XX_DIR_IN flag in mmio_74xx_dir_in() gpio: 74xx-mmio: Make use of device properties gpiolib: cdev: compile out HTE unless CONFIG_HTE selected gpiolib: cdev: consolidate edge detector configuration flags ...
2022-07-19gpiolib: cdev: compile out HTE unless CONFIG_HTE selectedKent Gibson
The majority of builds do not include HTE, so compile out hte functionality unless CONFIG_HTE is selected. Signed-off-by: Kent Gibson <warthog618@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19gpiolib: cdev: consolidate edge detector configuration flagsKent Gibson
Combine the polarity_change flag, struct line eflags, and hte enable flag into a single flag variable. The combination of these flags describes the configuration state of the edge detector, so formalize and clarify that by combining them into a single variable, edflags, in struct line. The edflags is a subset of the GPIO_V2_LINE_FLAGsb relevant to the edge detector, and is also a superset of the eflags it replaces. The eflags name is still used to describe the subset of edflags corresponding to the rising/falling edge flags where edflags is masked down to that subset. This consolidation reduces the number of variables being passed, simplifies state comparisons, and provides a more extensible foundation should additional edge sources be integrated in the future. Signed-off-by: Kent Gibson <warthog618@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19gpiolib: cdev: simplify line event identificationKent Gibson
Reorganise line event identification code to reduce code duplication, and replace if-else initializers with a helper function to improve readability. Signed-off-by: Kent Gibson <warthog618@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2022-07-19gpiolib: cdev: replace if-else chains with switchesKent Gibson
Improve readability by replacing if-else chains with switch statements. Signed-off-by: Kent Gibson <warthog618@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19gpiolib: cdev: simplify parameter in call to hte_edge_setupKent Gibson
Improve readability by using the GPIO_V2_LINE_FLAG_EDGE_BOTH instead of combining the rising and falling edge flags. Signed-off-by: Kent Gibson <warthog618@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Dipen Patel <dipenp@nvidia.com> Tested-by: Dipen Patel <dipenp@nvidia.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19gpiolib: cdev: simplify linereq_freeKent Gibson
The edge detector is only ever started after the line desc has been determined, so move edge_detector_stop() inside the line desc check, and merge the two checked regions into one. Signed-off-by: Kent Gibson <warthog618@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Dipen Patel <dipenp@nvidia.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-18Merge tag 'hte/for-5.19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux Pull hardware timestamp fix from Thierry Reding: "A single fix for an out-of-sync kerneldoc comment" * tag 'hte/for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux: gpiolib: cdev: Fix kernel doc for struct line
2022-07-07gpiolib: cdev: fix null pointer dereference in linereq_free()Kent Gibson
Fix a kernel NULL pointer dereference reported by gpio kselftests. linereq_free() can be called as part of the cleanup of a failed request, at which time the desc for a line may not have been determined, so it is unsafe to dereference without a check. Add a check prior to dereferencing the line desc. Fixes: 2068339a6c35 ("gpiolib: cdev: Add hardware timestamp clock type") Signed-off-by: Kent Gibson <warthog618@gmail.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-06-17gpiolib: cdev: Fix kernel doc for struct lineAndy Shevchenko
Kernel doc validator is not happy: gpiolib-cdev.c:487: warning: Function parameter or member 'hdesc' not described in 'line' gpiolib-cdev.c:487: warning: Function parameter or member 'raw_level' not described in 'line' gpiolib-cdev.c:487: warning: Function parameter or member 'total_discard_seq' not described in 'line' gpiolib-cdev.c:487: warning: Function parameter or member 'last_seqno' not described in 'line' Describe above mentioned parameters. Fixes: 2068339a6c35 ("gpiolib: cdev: Add hardware timestamp clock type") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Dipen Patel <dipenp@nvidia.com> Acked-by: Bartosz Golaszewski <brgl@bgdev.pl> Signed-off-by: Thierry Reding <treding@nvidia.com>
2022-06-05Merge tag 'hte/for-5.19-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux Pull hardware timestamping subsystem from Thierry Reding: "This contains the new HTE (hardware timestamping engine) subsystem that has been in the works for a couple of months now. The infrastructure provided allows for drivers to register as hardware timestamp providers, while consumers will be able to request events that they are interested in (such as GPIOs and IRQs) to be timestamped by the hardware providers. Note that this currently supports only one provider, but there seems to be enough interest in this functionality and we expect to see more drivers added once this is merged" [ Linus Walleij mentions the Intel PMC in the Elkhart and Tiger Lake platforms as another future timestamp provider ] * tag 'hte/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux: dt-bindings: timestamp: Correct id path dt-bindings: Renamed hte directory to timestamp hte: Uninitialized variable in hte_ts_get() hte: Fix off by one in hte_push_ts_ns() hte: Fix possible use-after-free in tegra_hte_test_remove() hte: Remove unused including <linux/version.h> MAINTAINERS: Add HTE Subsystem hte: Add Tegra HTE test driver tools: gpio: Add new hardware clock type gpiolib: cdev: Add hardware timestamp clock type gpio: tegra186: Add HTE support gpiolib: Add HTE support dt-bindings: Add HTE bindings hte: Add Tegra194 HTE kernel provider drivers: Add hardware timestamp engine (HTE) subsystem Documentation: Add HTE subsystem guide
2022-05-04gpiolib: cdev: Add hardware timestamp clock typeDipen Patel
This patch adds new clock type for the GPIO controller which can timestamp gpio lines in using hardware means. To expose such functionalities to the userspace, code has been added where during line create or set config API calls, it checks for new clock type and if requested, calls HTE API. During line change event, the HTE subsystem pushes timestamp data to userspace through gpiolib-cdev. Signed-off-by: Dipen Patel <dipenp@nvidia.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2022-04-05gpiolib: Get rid of redundant 'else'Andy Shevchenko
In the snippets like the following if (...) return / goto / break / continue ...; else ... the 'else' is redundant. Get rid of it. In case of IOCTLs use switch-case pattern that seems the usual in such cases. While at it, clarify necessity of else in gpiod_direction_output() by attaching else if to the closing curly brace on a previous line. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-02-08gpiolib: Never return internal error codes to user spaceAndy Shevchenko
Currently it's possible that character device interface may return the error codes which are not supposed to be seen by user space. In this case it's EPROBE_DEFER. Wrap it to return -ENODEV instead as sysfs does. Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines") Fixes: 61f922db7221 ("gpio: userspace ABI for reading GPIO line events") Fixes: 3c0d9c635ae2 ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL") Reported-by: Suresh Balakrishnan <suresh.balakrishnan@intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2021-06-22gpiolib: cdev: zero padding during conversion to gpioline_info_changedGabriel Knezek
When userspace requests a GPIO v1 line info changed event, lineinfo_watch_read() populates and returns the gpioline_info_changed structure. It contains 5 words of padding at the end which are not initialized before being returned to userspace. Zero the structure in gpio_v2_line_info_change_to_v1() before populating its contents. Fixes: aad955842d1c ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL") Signed-off-by: Gabriel Knezek <gabeknez@linux.microsoft.com> Reviewed-by: Kent Gibson <warthog618@gmail.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-01-27gpiolib: cdev: clear debounce period if line set to outputKent Gibson
When set_config changes a line from input to output debounce is implicitly disabled, as debounce makes no sense for outputs, but the debounce period is not being cleared and is still reported in the line info. So clear the debounce period when the debouncer is stopped in edge_detector_stop(). Fixes: 65cff7046406 ("gpiolib: cdev: support setting debounce") Cc: stable@vger.kernel.org Signed-off-by: Kent Gibson <warthog618@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-01-03gpiolib: cdev: fix frame size warning in gpio_ioctl()Kent Gibson
The kernel test robot reports the following warning in [1]: drivers/gpio/gpiolib-cdev.c: In function 'gpio_ioctl': >>drivers/gpio/gpiolib-cdev.c:1437:1: warning: the frame size of 1040 bytes is larger than 1024 bytes [-Wframe-larger-than=] Refactor gpio_ioctl() to handle each ioctl in its own helper function and so reduce the variables stored on the stack to those explicitly required to service the ioctl at hand. The lineinfo_get_v1() helper handles both the GPIO_GET_LINEINFO_IOCTL and GPIO_GET_LINEINFO_WATCH_IOCTL, as per the corresponding v2 implementation - lineinfo_get(). [1] https://lore.kernel.org/lkml/202012270910.VW3qc1ER-lkp@intel.com/ Fixes: aad955842d1c ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Kent Gibson <warthog618@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-12-09Merge tag 'gpio-updates-for-v5.11' of ↵Linus Walleij
git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux into devel gpio updates for v5.11-rc1 - several refactoring patches of the core gpiolib code - add support for NXP PCAL9554B/C to gpio-pca953x - allow probing mockup devices from device tree - refactoring and improvements to gpio-rcar - improvements to locking in gpio-tegra - code shrink in gpiolib devres - get the irq offset from device tree in gpio-sifive - major refactoring of gpio-exar - convert gpio-mvebu pwm access to regmap - create a new submenu for virtual GPIO drivers - fix clang fall-through warnings treewide - minor driver refactoring and tweaks sprinkled all over
2020-12-09gpiolib: cdev: Flag invalid GPIOs as usedMarc Zyngier
When reporting the state of a GPIO to userspace, we never check for the actual validity of the line, meaning we report invalid lines as being usable. A subsequent request will fail though, which is an inconsistent behaviour from a userspace perspective. Instead, let's check for the validity of the line and report it as used if it is invalid. This allows a tool such as gpioinfo to report something sensible: gpiochip3 - 4 lines: line 0: unnamed unused input active-high line 1: unnamed kernel input active-high [used] line 2: unnamed kernel input active-high [used] line 3: unnamed unused input active-high In this example, lines 1 and 2 are invalid, and cannot be used by userspace. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/20201204164739.781812-2-maz@kernel.org Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-12-05gpiolib: cdev: allow edge event timestamps to be configured as REALTIMEKent Gibson
Using CLOCK_REALTIME as the source for event timestamps is crucial for some specific applications, particularly those requiring timetamps relative to a PTP clock, so provide an option to switch the event timestamp source from the default CLOCK_MONOTONIC to CLOCK_REALTIME. Note that CLOCK_REALTIME was the default source clock for GPIO until Linux 5.7 when it was changed to CLOCK_MONOTONIC due to issues with the shifting of the realtime clock. Providing this option maintains the CLOCK_MONOTONIC as the default, while also providing a path forward for those dependent on the pre-5.7 behaviour. Suggested-by: Jack Winch <sunt.un.morcov@gmail.com> Signed-off-by: Kent Gibson <warthog618@gmail.com> Link: https://lore.kernel.org/r/20201014231158.34117-2-warthog618@gmail.com Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-10-30gpiolib: cdev: add GPIO_V2_LINE_FLAG_EDGE_BOTH and use it in edge_irq_thread()Kent Gibson
Add GPIO_V2_LINE_FLAG_EDGE_BOTH macro and use it in edge_irq_thread() to improve readability of edge handling cases. Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Kent Gibson <warthog618@gmail.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-10-28gpiolib: Switch to use compat_need_64bit_alignment_fixup() helperAndy Shevchenko
Use the new compat_need_64bit_alignment_fixup() helper to avoid ugly ifdeffery in IOCTL compatibility code. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Kent Gibson <warthog618@gmail.com> Depends-on: 527c412519eb ("compat: add a compat_need_64bit_alignment_fixup() helper") Link: https://lore.kernel.org/r/20201014103315.82662-1-andriy.shevchenko@linux.intel.com Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-10-26gpiolib: cdev: document that line eflags are sharedKent Gibson
The line.eflags field is shared so document this fact and highlight it throughout using READ_ONCE() and WRITE_ONCE() accessors. Also use a local copy of the eflags in edge_irq_thread() to ensure consistent control flow even if eflags changes. This is only a defensive measure as edge_irq_thread() is currently disabled when the eflags are changed. Signed-off-by: Kent Gibson <warthog618@gmail.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-10-13Merge tag 'gpio-v5.10-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio Pull GPIO updates from Linus Walleij: "This time very little driver changes but lots of core changes. We have some interesting cooperative work for ARM and Intel alike, making the GPIO subsystem more and more suitable for industrial systems and the like, in addition to the in-kernel users. We touch driver core (device properties) and lib/* by adding one simple string array free function, these are authored by Andy Shevchenko who is a well known and recognized core helpers maintainers so this should be fine. We also see some Android GKI-related modularization in the MXC drivers. Core changes: - The big core change is the updated (v2) userspace character device API. This corrects badly designed 64-bit alignment around the line events. We also add the debounce request feature. This echoes the often quotes passage from Frederick Brooks "The mythical man-month" to always throw one away, which we have seen before in things such as V4L2. So we put in a new one and deprecate and obsolete the old one. - All example tools in tools/gpio/* are migrated to the new API to set a good example. The libgpiod userspace library has been augmented to use this new API pretty much from day 1. - Some misc API hardening by using strn* function calls has been added as well. - Use the simpler IDA interface for GPIO chip instance enumeration. - Add device core function for counting string arrays in device properties. - Provide a generic library function kfree_strarray() that can be used throughout the kernel. Driver enhancements: - The DesignWare dwapb-gpio driver has been enhanced and now uses the IRQ handling in the gpiolib core. - The mockup and aggregator drivers have seen some substantial code clean-up and now use more of the core kernel inftrastructure. - Misc cleanups using dev_err_probe(). - The MXC drivers (Freescale/NXP) can now be built modularized, which makes modularized GKI Android kernels happy" * tag 'gpio-v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (73 commits) gpiolib: Update header block in gpiolib-cdev.h gpiolib: cdev: switch from kstrdup() to kstrndup() docs: gpio: add a new document to its index.rst gpio: pca953x: Add support for the NXP PCAL9554B/C tools: gpio: add debounce support to gpio-event-mon tools: gpio: add multi-line monitoring to gpio-event-mon tools: gpio: port gpio-event-mon to v2 uAPI tools: gpio: port gpio-hammer to v2 uAPI tools: gpio: rename nlines to num_lines tools: gpio: port gpio-watch to v2 uAPI tools: gpio: port lsgpio to v2 uAPI gpio: uapi: document uAPI v1 as deprecated gpiolib: cdev: support setting debounce gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL gpiolib: cdev: support edge detection for uAPI v2 gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL gpiolib: add build option for CDEV v1 ABI gpiolib: make cdev a build option ...
2020-10-08gpiolib: cdev: switch from kstrdup() to kstrndup()Kent Gibson
Use kstrndup() to copy line labels from the userspace provided char array, rather than ensuring the char array contains a null terminator and using kstrdup(). Note that the length provided to kstrndup() still assumes that the char array does contain a null terminator, so the maximum string length is one less than the array. This is consistent with the previous behaviour. Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Kent Gibson <warthog618@gmail.com> Link: https://lore.kernel.org/r/20201005070246.20927-1-warthog618@gmail.com Signed-off-by: Linus Walleij <linus.walleij@linaro.org>