JIRA: https://issues.redhat.com/browse/RHEL-39849
CVE: CVE-2024-36899
Build Info: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=61800387
Tested: Did sanity boot testing Intel (intel-arrowlake-s-02) system.
commit 02f6b0e1ec7e0e7d059dddc893645816552039da
Author: Zhongqiu Han <quic_zhonhan@quicinc.com>
Date: Sun May 5 22:11:56 2024 +0800
gpiolib: cdev: Fix use after free in lineinfo_changed_notify
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: 51c1064e82 ("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: Steve Best <sbest@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-26354
commit 00762e416cd2001270a59fab417fbb1c30e2b7e5
Author: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Date: Tue Oct 3 11:54:45 2023 +0200
treewide: rename pinctrl_gpio_can_use_line_new()
Now that pinctrl_gpio_can_use_line() is no longer used, let's drop the
'_new' suffix from its improved variant.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David Arcari <darcari@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-26354
commit 32fb7d23e76a4a89f9796c81dfde91b3d84257ef
Author: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Date: Tue Oct 3 09:15:14 2023 +0200
gpio: cdev: use pinctrl_gpio_can_use_line_new()
Use the improved variant of pinctrl_gpio_can_use_line() which takes a
pointer to the gpio_chip and a controller-relative offset.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David Arcari <darcari@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-946
commit 9ce4ed5b4db13633f9934a4eac02c4cde04d5c63
Author: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Date: Mon Aug 21 16:18:27 2023 +0200
gpiolib: provide and use gpiod_line_state_notify()
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>
Signed-off-by: Izabela Bakollari <ibakolla@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-946
commit a067419ba77da830939852758702388f0fba09a1
Author: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Date: Thu Aug 17 13:59:05 2023 +0200
gpiolib: add a second blocking notifier to struct gpio_device
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>
Signed-off-by: Izabela Bakollari <ibakolla@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-946
commit 17a7ca35890b411414a71fbeef13cb65fe9511df
Author: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Date: Thu Aug 17 10:52:28 2023 +0200
gpiolib: rename the gpio_device notifier
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>
Signed-off-by: Izabela Bakollari <ibakolla@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2183344
commit bdbbae241a04f387ba910b8609f95fad5f1470c7
Author: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Date: Mon Dec 5 13:39:03 2022 +0100
gpiolib: protect the GPIO device against being dropped while in use by 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: d7c51b47ac ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 3c0d9c635a ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL")
Fixes: aad955842d ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Fixes: a54756cb24 ("gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL")
Fixes: 7b8e00d981 ("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>
Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2183344
commit 533aae7c94dbc2b14301cfd68ae7e0e90f0c8438
Author: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Date: Mon Dec 5 13:39:02 2022 +0100
gpiolib: cdev: fix NULL-pointer dereferences
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: d7c51b47ac ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 3c0d9c635a ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL")
Fixes: aad955842d ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Fixes: a54756cb24 ("gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL")
Fixes: 7b8e00d981 ("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>
Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2183344
commit 8d259847243d1e21a866e828c4ce90d759f3d17b
Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Thu Oct 20 18:39:14 2022 +0300
gpiolib: cdev: Fix typo in kernel doc for struct line
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>
Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2183344
commit 52ee7c02f67808afa533c523fa3e4b66c54ea758
Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Fri Oct 7 16:44:44 2022 +0300
gpiolib: cdev: Add missing header(s)
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>
Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2183344
commit 0ae3109a839192920f09338e9abc4d5321107865
Author: Bartosz Golaszewski <brgl@bgdev.pl>
Date: Thu Sep 22 11:51:24 2022 +0200
gpiolib: cdev: add fdinfo output for line request file descriptors
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>
Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2183344
commit 69bef19d6b9700e96285f4b4e28691cda3dcd0d1
Author: Meng Li <Meng.Li@windriver.com>
Date: Wed Sep 21 11:20:20 2022 +0800
gpiolib: cdev: Set lineevent_state::irq after IRQ register successfully
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: 4682427241 ("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>
Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2183344
commit 272ddba004731503cb6c30f2336dd501eaf25955
Author: Kent Gibson <warthog618@gmail.com>
Date: Thu Jul 14 10:03:19 2022 +0800
gpiolib: cdev: compile out HTE unless CONFIG_HTE selected
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>
Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2183344
commit b1a92e94560def63b71057d770e9db2f798ab58c
Author: Kent Gibson <warthog618@gmail.com>
Date: Thu Jul 14 10:03:18 2022 +0800
gpiolib: cdev: consolidate edge detector configuration flags
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>
Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2183344
commit 160d6e402900672d4b0689a7c939be487460a1fe
Author: Kent Gibson <warthog618@gmail.com>
Date: Thu Jul 14 10:03:14 2022 +0800
gpiolib: cdev: simplify linereq_free
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>
Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2071835
Tested: This is one of a series of patch sets to enable Arm SystemReady IR
support in the kernel for NXP i.MX8 platforms. This set updates GPIO
support. It has been tested via simple boot tests and by using the
kernel GPIO tools to verify pins are being identified and can be used.
commit c8e27a4a5136e7230f9e4ffcf132705bf56864cc
Author: Kent Gibson <warthog618@gmail.com>
Date: Wed Jul 6 16:45:07 2022 +0800
gpiolib: cdev: fix null pointer dereference in linereq_free()
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>
(cherry picked from commit c8e27a4a5136e7230f9e4ffcf132705bf56864cc)
Signed-off-by: Al Stone <ahs3@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2071835
Tested: This is one of a series of patch sets to enable Arm SystemReady IR
support in the kernel for NXP i.MX8 platforms. This set updates GPIO
support. It has been tested via simple boot tests and by using the
kernel GPIO tools to verify pins are being identified and can be used.
commit 85ff37e302efdf173cff6d1a310c2f7f38f1d069
Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Fri May 20 19:47:26 2022 +0300
gpiolib: cdev: Fix kernel doc for struct line
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>
(cherry picked from commit 85ff37e302efdf173cff6d1a310c2f7f38f1d069)
Signed-off-by: Al Stone <ahs3@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2071835
Tested: This is one of a series of patch sets to enable Arm SystemReady IR
support in the kernel for NXP i.MX8 platforms. This set updates GPIO
support. It has been tested via simple boot tests and by using the
kernel GPIO tools to verify pins are being identified and can be used.
commit 2068339a6c35147847ba433fd0da67b313779059
Author: Dipen Patel <dipenp@nvidia.com>
Date: Fri Apr 22 13:52:18 2022 -0700
gpiolib: cdev: Add hardware timestamp clock type
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>
(cherry picked from commit 2068339a6c35147847ba433fd0da67b313779059)
Signed-off-by: Al Stone <ahs3@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2071835
Tested: This is one of a series of patch sets to enable Arm SystemReady IR
support in the kernel for NXP i.MX8 platforms. This set updates GPIO
support. It has been tested via simple boot tests and by using the
kernel GPIO tools to verify pins are being identified and can be used.
commit 1cef8b5019769d46725932eeace7a383bca97905
Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Wed Mar 30 18:06:20 2022 +0300
gpiolib: Get rid of redundant 'else'
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>
(cherry picked from commit 1cef8b5019769d46725932eeace7a383bca97905)
Signed-off-by: Al Stone <ahs3@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2071835
Tested: This is one of a series of patch sets to enable Arm SystemReady IR
support in the kernel for NXP i.MX8 platforms. This set updates GPIO
support. It has been tested via simple boot tests and by using the
kernel GPIO tools to verify pins are being identified and can be used.
commit 95a4eed7dd5b7c1c3664a626174290686ddbee9f
Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Tue Feb 1 17:27:55 2022 +0200
gpiolib: Never return internal error codes to user space
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: d7c51b47ac ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 61f922db72 ("gpio: userspace ABI for reading GPIO line events")
Fixes: 3c0d9c635a ("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>
(cherry picked from commit 95a4eed7dd5b7c1c3664a626174290686ddbee9f)
Signed-off-by: Al Stone <ahs3@redhat.com>
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: aad955842d ("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>
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: 65cff70464 ("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>
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: aad955842d ("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>
- 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
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Merge tag 'gpio-updates-for-v5.11' of 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
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>
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>
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>
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: 527c412519 ("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>
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>
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.
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Merge tag 'gpio-v5.10-1' of 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
...
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>
It appears that UML (arch/um) has no compat.h header defined and hence
can't compile a recently provided piece of code in GPIO library.
Disable compat ->read() code in UML case to avoid compilation errors.
While at it, use pattern which is already being used in the kernel elsewhere.
Fixes: 5ad284ab3a ("gpiolib: Fix line event handling in syscall compatible mode")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20201005131044.87276-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Add support for setting debounce on a line via the GPIO uAPI.
Where debounce is not supported by hardware, a software debounce is
provided.
The implementation of the software debouncer waits for the line to be
stable for the debounce period before determining if a level change,
and a corresponding edge event, has occurred. This provides maximum
protection against glitches, but also introduces a debounce_period
latency to edge events.
The software debouncer is integrated with the edge detection as it
utilises the line interrupt, and integration is simpler than getting
the two to interwork. Where software debounce AND edge detection is
required, the debouncer provides both.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Add support for the GPIO_V2_LINE_SET_VALUES_IOCTL.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Add support for GPIO_V2_LINE_SET_CONFIG_IOCTL, the uAPI v2
line set config ioctl.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Add support for edge detection to lines requested using
GPIO_V2_GET_LINE_IOCTL.
The edge_detector implementation is based on the v1 lineevent
implementation. Unlike the v1 implementation, an overflow of the event
buffer results in discarding older events, rather than the most
recent, so the final event in a burst will correspond to the current
state of the line.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Add support for GPIO_V2_GET_LINEINFO_IOCTL and
GPIO_V2_GET_LINEINFO_WATCH_IOCTL.
The core of this change is the event kfifo switching to contain
struct gpioline_info_changed_v2, instead of v1 as v2 is richer.
The two uAPI versions are mostly independent - other than where they both
provide line info changes via reads on the chip fd. As the info change
structs differ between v1 and v2, the infowatch implementation tracks which
version of the infowatch ioctl, either GPIO_GET_LINEINFO_WATCH_IOCTL or
GPIO_V2_GET_LINEINFO_WATCH_IOCTL, initiates the initial watch and returns
the corresponding info change struct to the read. The version supported
on that fd locks to that version on the first watch request, so subsequent
watches from that process must use the same uAPI version.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Add support for requesting lines using the GPIO_V2_GET_LINE_IOCTL, and
returning their current values using GPIO_V2_LINE_GET_VALUES_IOCTL.
The struct linereq implementation is based on the v1 struct linehandle
implementation.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Replace usage of strncpy() with strscpy() to remove -Wstringop-truncation
warnings.
The structures being populated are zeroed, to prevent stack leakage as
they are returned to userspace, so strscpy() performs the equivalent
function without the warnings.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Set the value of the line info offset in gpio_desc_to_lineinfo(), rather
than relying on it being passed in the info. This makes the function
behave as you would expect from the name - it generates the line info
corresponding to a given GPIO desc.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
The introduced line event handling ABI in the commit
61f922db72 ("gpio: userspace ABI for reading GPIO line events")
missed the fact that 64-bit kernel may serve for 32-bit applications.
In such case the very first check in the lineevent_read() will fail
due to alignment differences.
To workaround this introduce lineevent_get_size() helper which returns actual
size of the structure in user space.
Fixes: 61f922db72 ("gpio: userspace ABI for reading GPIO line events")
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Consolidate the cleanup of lineevents, currently duplicated in
lineevent_create and lineevent_release, into a helper function
lineevent_free.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Consolidate the cleanup of linehandles, currently duplicated in
linehandle_create and linehandle_release, into a helper function
linehandle_free.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Remove recalculation of offset from desc, where desc itself was calculated
from offset.
There is no benefit from the desc -> hwgpio conversion in this context.
The only implicit benefit of the offset -> desc -> hwgpio is
the range check in the offset -> desc, but where desc is required you
still get that, and where desc isn't required it is simpler to perform
the range check directly.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Merge separate usage of test_bit/set_bit into test_and_set_bit to remove
the possibility of a race between the test and set.
Similarly test_bit and clear_bit.
In the existing code it is possible for two threads to race past the
test_bit and then set or clear the watch bit, and neither return EBUSY.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Rename priv to cdev to improve readability.
The name "priv" indicates that the object is pointed to by
file->private_data, not what the object is actually is.
As it is always used to point to a struct gpio_chardev_data, renaming
it to cdev is more appropriate.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Steve Best
David Arcari
Izabela Bakollari
Shaoqin Huang
Al Stone
Gabriel Knezek
Kent Gibson
Linus Walleij
Marc Zyngier
Andy Shevchenko
Linus Torvalds