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2018-02-17iio: adis_lib: Initialize trigger before requesting interruptLars-Peter Clausen1-3/+4
The adis_probe_trigger() creates a new IIO trigger and requests an interrupt associated with the trigger. The interrupt uses the generic iio_trigger_generic_data_rdy_poll() function as its interrupt handler. Currently the driver initializes some fields of the trigger structure after the interrupt has been requested. But an interrupt can fire as soon as it has been requested. This opens up a race condition. iio_trigger_generic_data_rdy_poll() will access the trigger data structure and dereference the ops field. If the ops field is not yet initialized this will result in a NULL pointer deref. It is not expected that the device generates an interrupt at this point, so typically this issue did not surface unless e.g. due to a hardware misconfiguration (wrong interrupt number, wrong polarity, etc.). But some newer devices from the ADIS family start to generate periodic interrupts in their power-on reset configuration and unfortunately the interrupt can not be masked in the device. This makes the race condition much more visible and the following crash has been observed occasionally when booting a system using the ADIS16460. Unable to handle kernel NULL pointer dereference at virtual address 00000008 pgd = c0004000 [00000008] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-04126-gf9739f0-dirty #257 Hardware name: Xilinx Zynq Platform task: ef04f640 task.stack: ef050000 PC is at iio_trigger_notify_done+0x30/0x68 LR is at iio_trigger_generic_data_rdy_poll+0x18/0x20 pc : [<c042d868>] lr : [<c042d924>] psr: 60000193 sp : ef051bb8 ip : 00000000 fp : ef106400 r10: c081d80a r9 : ef3bfa00 r8 : 00000087 r7 : ef051bec r6 : 00000000 r5 : ef3bfa00 r4 : ee92ab00 r3 : 00000000 r2 : 00000000 r1 : 00000000 r0 : ee97e400 Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none Control: 18c5387d Table: 0000404a DAC: 00000051 Process swapper/0 (pid: 1, stack limit = 0xef050210) [<c042d868>] (iio_trigger_notify_done) from [<c0065b10>] (__handle_irq_event_percpu+0x88/0x118) [<c0065b10>] (__handle_irq_event_percpu) from [<c0065bbc>] (handle_irq_event_percpu+0x1c/0x58) [<c0065bbc>] (handle_irq_event_percpu) from [<c0065c30>] (handle_irq_event+0x38/0x5c) [<c0065c30>] (handle_irq_event) from [<c0068e28>] (handle_level_irq+0xa4/0x130) [<c0068e28>] (handle_level_irq) from [<c0064e74>] (generic_handle_irq+0x24/0x34) [<c0064e74>] (generic_handle_irq) from [<c021ab7c>] (zynq_gpio_irqhandler+0xb8/0x13c) [<c021ab7c>] (zynq_gpio_irqhandler) from [<c0064e74>] (generic_handle_irq+0x24/0x34) [<c0064e74>] (generic_handle_irq) from [<c0065370>] (__handle_domain_irq+0x5c/0xb4) [<c0065370>] (__handle_domain_irq) from [<c000940c>] (gic_handle_irq+0x48/0x8c) [<c000940c>] (gic_handle_irq) from [<c0013e8c>] (__irq_svc+0x6c/0xa8) To fix this make sure that the trigger is fully initialized before requesting the interrupt. Fixes: ccd2b52f4ac6 ("staging:iio: Add common ADIS library") Reported-by: Robin Getz <Robin.Getz@analog.com> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2017-08-22iio:imu: drop assign iio_info.driver_module and iio_trigger_ops.ownerJonathan Cameron1-1/+0
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. Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
2015-03-28iio: imu: Use iio_trigger_get for indio_dev->trig assignmentDarshana Padmadas1-1/+1
This patch uses iio_trigger_get to increment the reference count of trigger device, to avoid incorrect assignment. Can result in a null pointer dereference during removal if the trigger has been changed before removal. This patch refers to a similar situation encountered through the following discussion: http://www.spinics.net/lists/linux-iio/msg13669.html Signed-off-by: Darshana Padmadas <darshanapadmadas@gmail.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-03-25iio:trigger: Introduce iio_tigger_{set,get}_drvdataLars-Peter Clausen1-2/+2
Introduce iio_tigger_{set,get}_drvdata which allows to attach driver specific data to a trigger. The functions wrap access to the triggers private_data field and all current users are updated to use iio_tigger_{set,get}_drvdata instead of directly accessing the private_data field. This is the first step towards removing the private_data field from the iio_trigger struct. The following coccinelle script has been used to update the drivers: <smpl> @@ struct iio_trigger *trigger; expression priv; @@ -trigger->private_data = priv +iio_trigger_set_drv_data(trigger, priv) @@ struct iio_trigger *trigger; @@ -trigger->private_data +iio_trigger_get_drv_data(trigger) </smpl> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-11-19staging:iio: Move adis library out of stagingLars-Peter Clausen1-0/+89
Now that the adis library no longer depends on the sw_ring buffer implementation we can move it out of staging. While we are at it also sort the entries in the iio Kconfig and Makefile to be in alphabetical order. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>