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path: root/drivers/comedi/drivers.c
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4 daysMerge tag 'char-misc-6.17-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char / misc / IIO / other driver updates from Greg KH: "Here is the big set of char/misc/iio and other smaller driver subsystems for 6.17-rc1. It's a big set this time around, with the huge majority being in the iio subsystem with new drivers and dts files being added there. Highlights include: - IIO driver updates, additions, and changes making more code const and cleaning up some init logic - bus_type constant conversion changes - misc device test functions added - rust miscdevice minor fixup - unused function removals for some drivers - mei driver updates - mhi driver updates - interconnect driver updates - Android binder updates and test infrastructure added - small cdx driver updates - small comedi fixes - small nvmem driver updates - small pps driver updates - some acrn virt driver fixes for printk messages - other small driver updates All of these have been in linux-next with no reported issues" * tag 'char-misc-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (292 commits) binder: Use seq_buf in binder_alloc kunit tests binder: Add copyright notice to new kunit files misc: ti_fpc202: Switch to of_fwnode_handle() bus: moxtet: Use dev_fwnode() pc104: move PC104 option to drivers/Kconfig drivers: virt: acrn: Don't use %pK through printk comedi: fix race between polling and detaching interconnect: qcom: Add Milos interconnect provider driver dt-bindings: interconnect: document the RPMh Network-On-Chip Interconnect in Qualcomm Milos SoC mei: more prints with client prefix mei: bus: use cldev in prints bus: mhi: host: pci_generic: Add Telit FN990B40 modem support bus: mhi: host: Detect events pointing to unexpected TREs bus: mhi: host: pci_generic: Add Foxconn T99W696 modem bus: mhi: host: Use str_true_false() helper bus: mhi: host: pci_generic: Add support for EM929x and set MRU to 32768 for better performance. bus: mhi: host: Fix endianness of BHI vector table bus: mhi: host: pci_generic: Disable runtime PM for QDU100 bus: mhi: host: pci_generic: Fix the modem name of Foxconn T99W640 dt-bindings: interconnect: qcom,msm8998-bwmon: Allow 'nonposted-mmio' ...
11 dayscomedi: fix race between polling and detachingIan Abbott
syzbot reports a use-after-free in comedi in the below link, which is due to comedi gladly removing the allocated async area even though poll requests are still active on the wait_queue_head inside of it. This can cause a use-after-free when the poll entries are later triggered or removed, as the memory for the wait_queue_head has been freed. We need to check there are no tasks queued on any of the subdevices' wait queues before allowing the device to be detached by the `COMEDI_DEVCONFIG` ioctl. Tasks will read-lock `dev->attach_lock` before adding themselves to the subdevice wait queue, so fix the problem in the `COMEDI_DEVCONFIG` ioctl handler by write-locking `dev->attach_lock` before checking that all of the subdevices are safe to be deleted. This includes testing for any sleepers on the subdevices' wait queues. It remains locked until the device has been detached. This requires the `comedi_device_detach()` function to be refactored slightly, moving the bulk of it into new function `comedi_device_detach_locked()`. Note that the refactor of `comedi_device_detach()` results in `comedi_device_cancel_all()` now being called while `dev->attach_lock` is write-locked, which wasn't the case previously, but that does not matter. Thanks to Jens Axboe for diagnosing the problem and co-developing this patch. Cc: stable <stable@kernel.org> Fixes: 2f3fdcd7ce93 ("staging: comedi: add rw_semaphore to protect against device detachment") Link: https://lore.kernel.org/all/687bd5fe.a70a0220.693ce.0091.GAE@google.com/ Reported-by: syzbot+01523a0ae5600aef5895@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=01523a0ae5600aef5895 Co-developed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Tested-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20250722155316.27432-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-16comedi: Fix use of uninitialized data in insn_rw_emulate_bits()Ian Abbott
For Comedi `INSN_READ` and `INSN_WRITE` instructions on "digital" subdevices (subdevice types `COMEDI_SUBD_DI`, `COMEDI_SUBD_DO`, and `COMEDI_SUBD_DIO`), it is common for the subdevice driver not to have `insn_read` and `insn_write` handler functions, but to have an `insn_bits` handler function for handling Comedi `INSN_BITS` instructions. In that case, the subdevice's `insn_read` and/or `insn_write` function handler pointers are set to point to the `insn_rw_emulate_bits()` function by `__comedi_device_postconfig()`. For `INSN_WRITE`, `insn_rw_emulate_bits()` currently assumes that the supplied `data[0]` value is a valid copy from user memory. It will at least exist because `do_insnlist_ioctl()` and `do_insn_ioctl()` in "comedi_fops.c" ensure at lease `MIN_SAMPLES` (16) elements are allocated. However, if `insn->n` is 0 (which is allowable for `INSN_READ` and `INSN_WRITE` instructions, then `data[0]` may contain uninitialized data, and certainly contains invalid data, possibly from a different instruction in the array of instructions handled by `do_insnlist_ioctl()`. This will result in an incorrect value being written to the digital output channel (or to the digital input/output channel if configured as an output), and may be reflected in the internal saved state of the channel. Fix it by returning 0 early if `insn->n` is 0, before reaching the code that accesses `data[0]`. Previously, the function always returned 1 on success, but it is supposed to be the number of data samples actually read or written up to `insn->n`, which is 0 in this case. Reported-by: syzbot+cb96ec476fb4914445c9@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=cb96ec476fb4914445c9 Fixes: ed9eccbe8970 ("Staging: add comedi core") Cc: stable@vger.kernel.org # 5.13+ Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Link: https://lore.kernel.org/r/20250707153355.82474-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-16comedi: Fix some signed shift left operationsIan Abbott
Correct some left shifts of the signed integer constant 1 by some unsigned number less than 32. Change the constant to 1U to avoid shifting a 1 into the sign bit. The corrected functions are comedi_dio_insn_config(), comedi_dio_update_state(), and __comedi_device_postconfig(). Fixes: e523c6c86232 ("staging: comedi: drivers: introduce comedi_dio_insn_config()") Fixes: 05e60b13a36b ("staging: comedi: drivers: introduce comedi_dio_update_state()") Fixes: 09567cb4373e ("staging: comedi: initialize subdevice s->io_bits in postconfig") Cc: stable@vger.kernel.org # 5.13+ Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Link: https://lore.kernel.org/r/20250707121555.65424-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-05comedi: comedi_8254: Replace comedi_8254_init() and comedi_8254_mm_init()Ian Abbott
`comedi_8254_init()` and `comedi_8254_mm_init()` return `NULL` on failure, but the failure is not necessarily due to lack of memory. Change them to return an `ERR_PTR` value on failure and rename the functions to make it obvious the API has changed. `comedi_8254_init()` has been replaced with `comedi_8254_io_alloc()`, and `comedi_8254_mm_init()` has been replaced with `comedi_8254_mm_alloc()`. Cc: Arnd Bergmann <arnd@kernel.org> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Link: https://lore.kernel.org/r/20230913170712.111719-4-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-19drivers: comedi: replace ternary operator with min()Guo Zhengkui
Fix the following coccicheck warning: drivers/comedi/drivers.c:857:12-13: WARNING opportunity for min(). min() macro is defined in include/linux/minmax.h. It avoids multiple evaluations of the arguments when non-constant and performs strict type-checking. Reviewed-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com> Link: https://lore.kernel.org/r/20220513071608.49047-1-guozhengkui@vivo.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26comedi: Move the main COMEDI headersIan Abbott
Move the main COMEDI driver headers out of "drivers/comedi/" into new directory "include/linux/comedi/". These are "comedidev.h", "comedilib.h", "comedi_pci.h", "comedi_pcmcia.h", and "comedi_usb.h". Additionally, move the user-space API header "comedi.h" into "include/uapi/linux/" and add "WITH Linux-syscall-note" to its SPDX-License-Identifier. Update the "COMEDI DRIVERS" section of the MAINTAINERS file to account for these changes. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Link: https://lore.kernel.org/r/20211117120604.117740-2-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15staging: comedi: move out of staging directoryGreg Kroah-Hartman
The comedi code came into the kernel back in 2008, but traces its lifetime to much much earlier. It's been polished and buffed and there's really nothing preventing it from being part of the "real" portion of the kernel. So move it to drivers/comedi/ as it belongs there. Many thanks to the hundreds of developers who did the work to make this happen. Cc: Ian Abbott <abbotti@mev.co.uk> Cc: H Hartley Sweeten <hsweeten@visionengravers.com> Link: https://lore.kernel.org/r/YHauop4u3sP6lz8j@kroah.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>