iio: trigger: sysfs: rename error label in iio_sysfs_trigger_probe()

Rename error label in iio_sysfs_trigger_probe() to make more readable.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221024105250.873394-1-yangyingliang@huawei.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: trigger: sysfs: fix possible memory leak in iio_sysfs_trig_init()

dev_set_name() allocates memory for name, it need be freed
when device_add() fails, call put_device() to give up the
reference that hold in device_initialize(), so that it can
be freed in kobject_cleanup() when the refcount hit to 0.

Fault injection test can trigger this:

unreferenced object 0xffff8e8340a7b4c0 (size 32):
comm "modprobe", pid 243, jiffies 4294678145 (age 48.845s)
hex dump (first 32 bytes):
69 69 6f 5f 73 79 73 66 73 5f 74 72 69 67 67 65 iio_sysfs_trigge
72 00 a7 40 83 8e ff ff 00 86 13 c4 f6 ee ff ff r..@............
backtrace:
[<0000000074999de8>] __kmem_cache_alloc_node+0x1e9/0x360
[<00000000497fd30b>] __kmalloc_node_track_caller+0x44/0x1a0
[<000000003636c520>] kstrdup+0x2d/0x60
[<0000000032f84da2>] kobject_set_name_vargs+0x1e/0x90
[<0000000092efe493>] dev_set_name+0x4e/0x70

Fixes: 1f785681a870 ("staging:iio:trigger sysfs userspace trigger rework.")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20221022074212.1386424-1-yangyingliang@huawei.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: trigger: sysfs: fix use-after-free on remove

Ensure that the irq_work has completed before the trigger is freed.

==================================================================
BUG: KASAN: use-after-free in irq_work_run_list
Read of size 8 at addr 0000000064702248 by task python3/25

Call Trace:
irq_work_run_list
irq_work_tick
update_process_times
tick_sched_handle
tick_sched_timer
__hrtimer_run_queues
hrtimer_interrupt

Allocated by task 25:
kmem_cache_alloc_trace
iio_sysfs_trig_add
dev_attr_store
sysfs_kf_write
kernfs_fop_write_iter
new_sync_write
vfs_write
ksys_write
sys_write

Freed by task 25:
kfree
iio_sysfs_trig_remove
dev_attr_store
sysfs_kf_write
kernfs_fop_write_iter
new_sync_write
vfs_write
ksys_write
sys_write

==================================================================

Fixes: f38bc926d022 ("staging:iio:sysfs-trigger: Use irq_work to properly active trigger")
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20220519091925.1053897-1-vincent.whitchurch@axis.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: sysfs-trigger: replace usage of found with dedicated list iterator variable

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].

This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220331230632.957634-3-jakobkoschel@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: sysfs-trigger: Remove no-op trigger ops

The IIO core handles a trigger ops with all NULL callbacks the
same as if the trigger ops itself was NULL.

Remove the empty trigger ops from the interrupt trigger driver to slightly
reduce the boilerplate code. Object size of the driver module is also
slightly reduced.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211031142130.20791-2-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: set default trig->dev.parent

When allocated with [devm_]iio_trigger_alloc(), set trig device parent to
the device the trigger is allocated for by default.

It can always be reassigned in the probe routine.

Change iio_trigger_alloc() API to add the device pointer to be coherent
with devm_iio_trigger_alloc, using similar interface to
iio_device_alloc().

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210309193620.2176163-2-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: sysfs-trigger: Mark irq_work to expire in hardirq context

Mark the IIO sysfs-trigger irq_work with IRQ_WORK_HARD_IRQ to ensure that
it is always executed in hard interrupt context, even with PREEMPT_RT=y.

The IIO sysfs-trigger irq_work needs to run in hard interrupt context since
it will end up calling generic_handle_irq() which has the requirement to
run in hard interrupt context.

Note that the IRQ_WORK_HARD_IRQ flag, while it exists, does not seem to do
anything in the mainline kernel yet. It does have an effect in the RT
patchset though and presumably this is sooner or later going to be added to
mainline as well.

Reported-by: Christian Eggers <ceggers@arri.de>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20201117103751.16131-2-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 177

Based on 1 normalized pattern(s):

licensed under the gpl 2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 135 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170026.071193225@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers: iio: Update MODULE AUTHOR email address

no functional changes

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:triggers: drop assign iio_info.driver_module and iio_trigger_ops.owner

The equivalent of both of these are now done via macro magic when
the relevant register calls are made. The actual structure
elements will shortly go away.

Note that stm32-timer-trigger has expanded rather beyond triggers
(to include encoder input counting for example) and hence has an
iio_info structure.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>

iio: trigger: free trigger resource correctly

These stand-alone trigger drivers were using iio_trigger_put()
where they should have been using iio_trigger_free(). The
iio_trigger_put() adds a module_put which is bad since they
never did a module_get.

In the sysfs driver, module_get/put's are used as triggers are
added & removed. This extra module_put() occurs on an error path
in the probe routine (probably rare).

In the bfin-timer & interrupt trigger drivers, the module resources
are not explicitly managed, so it's doing a put on something that
was never get'd. It occurs on the probe error path and on the
remove path (not so rare).

Tested with the sysfs trigger driver.
The bfin & interrupt drivers were build tested & inspected only.

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: trigger: Add a blank line after declarations

This patch fixes the following checkpatch.pl warning:
WARNING: Missing a blank line after declarations

Signed-off-by: Roberta Dobrescu <roberta.dobrescu@gmail.com>
Reviewed-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: Remove timestamp argument from iio_trigger_poll() and iio_trigger_poll_chained()

argument has been ignored; adjust drivers accordingly

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:trigger: fix sysfs name on list mutex

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: replace strict_strtoul() with kstrtoul()

The usage of strict_strtoul() is not preferred, because
strict_strtoul() is obsolete. Thus, kstrtoul() should be
used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:trigger:sysfs Move out of staging.

This simple driver is rather useful. No issues about its interface
have been raised for some time hence the proposal to move it out
of staging.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>