kernel/linux.git/drivers/staging/comedi, branch v3.4.34

staging: comedi: disallow COMEDI_DEVCONFIG on non-board minors

2013-02-28T14:59:04+00:00

commit 754ab5c0e55dd118273ca2c217c4d95e9fbc8259 upstream. Comedi has two sorts of minor devices: (a) normal board minor devices in the range 0 to COMEDI_NUM_BOARD_MINORS-1 inclusive; and (b) special subdevice minor devices in the range COMEDI_NUM_BOARD_MINORS upwards that are used to open the same underlying comedi device as the normal board minor devices, but with non-default read and write subdevices for asynchronous commands. The special subdevice minor devices get created when a board supporting asynchronous commands is attached to a normal board minor device, and destroyed when the board is detached from the normal board minor device. One way to attach or detach a board is by using the COMEDI_DEVCONFIG ioctl. This should only be used on normal board minors as the special subdevice minors are too ephemeral. In particular, the change introduced in commit 7d3135af399e92cf4c9bbc5f86b6c140aab3b88c ("staging: comedi: prevent auto-unconfig of manually configured devices") breaks horribly for special subdevice minor devices. Since there's no legitimate use for the COMEDI_DEVCONFIG ioctl on a special subdevice minor device node, disallow it and return -ENOTTY. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

staging: comedi: Kconfig: COMEDI_NI_AT_A2150 should select COMEDI_FC

2013-01-17T16:51:21+00:00

commit 34ffb33e09132401872fe79e95c30824ce194d23 upstream. The 'ni_at_a2150' module links to `cfc_write_to_buffer` in the 'comedi_fc' module, so selecting 'COMEDI_NI_AT_A2150' in the kernel config needs to also select 'COMEDI_FC'. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

staging: comedi: don't hijack hardware device private data

2013-01-17T16:51:21+00:00

commit c43435d7722134ed1fda58ce1025f41029bd58ad upstream. comedi_auto_config() associates a Comedi minor device number with an auto-configured hardware device and comedi_auto_unconfig() disassociates it. Currently, these use the hardware device's private data pointer to point to some allocated storage holding the minor device number. This is a bit of a waste of the hardware device's private data pointer, preventing it from being used for something more useful by the low-level comedi device drivers. For example, it would make more sense if comedi_usb_auto_config() was passed a pointer to the struct usb_interface instead of the struct usb_device, but this cannot be done currently because the low-level comedi drivers already use the private data pointer in the struct usb_interface for something more useful. This patch stops the comedi core hijacking the hardware device's private data pointer. Instead, comedi_auto_config() stores a pointer to the hardware device's struct device in the struct comedi_device_file_info associated with the minor device number, and comedi_auto_unconfig() calls new function comedi_find_board_minor() to recover the minor device number associated with the hardware device. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

staging: comedi: comedi_test: fix race when cancelling command

2013-01-17T16:50:56+00:00

commit c0729eeefdcd76db338f635162bf0739fd2c5f6f upstream. Éric Piel reported a kernel oops in the "comedi_test" module. It was a NULL pointer dereference within `waveform_ai_interrupt()` (actually a timer function) that sometimes occurred when a running asynchronous command is cancelled (either by the `COMEDI_CANCEL` ioctl or by closing the device file). This seems to be a race between the caller of `waveform_ai_cancel()` which on return from that function goes and tears down the running command, and the timer function which uses the command. In particular, `async->cmd.chanlist` gets freed (and the pointer set to NULL) by `do_become_nonbusy()` in "comedi_fops.c" but a previously scheduled `waveform_ai_interrupt()` timer function will dereference that pointer regardless, leading to the oops. Fix it by replacing the `del_timer()` call in `waveform_ai_cancel()` with `del_timer_sync()`. Signed-off-by: Ian Abbott Reported-by: Éric Piel Signed-off-by: Greg Kroah-Hartman

staging: comedi: fix minimum AO period for NI 625x and NI 628x

2013-01-17T16:50:55+00:00

commit 34b55d8c48f4f76044d8f4d6ec3dc786cf210312 upstream. The minimum period was set to 357 ns, while the divider for these boards is 50 ns. This prevented to output at maximum speed as ni_ao_cmdtest() would return 357 but would not accept it. Not sure why it was set to 357 ns (this was done before the git history, which starts 5 years ago). My guess is that it comes from reading the specification stating a 2.8 MHz rate (~ 357 ns). The latest specification states a 2.86 MHz rate (~ 350 ns), which makes a lot more sense. Tested on a pci-6251. Signed-off-by: Éric Piel Acked-By: Ian Abbott Signed-off-by: Greg Kroah-Hartman

staging: comedi: prevent auto-unconfig of manually configured devices

2013-01-17T16:50:55+00:00

commit 7d3135af399e92cf4c9bbc5f86b6c140aab3b88c upstream. When a low-level comedi driver auto-configures a device, a `struct comedi_dev_file_info` is allocated (as well as a `struct comedi_device`) by `comedi_alloc_board_minor()`. A pointer to the hardware `struct device` is stored as a cookie in the `struct comedi_dev_file_info`. When the low-level comedi driver auto-unconfigures the device, `comedi_auto_unconfig()` uses the cookie to find the `struct comedi_dev_file_info` so it can detach the comedi device from the driver, clean it up and free it. A problem arises if the user manually unconfigures and reconfigures the comedi device using the `COMEDI_DEVCONFIG` ioctl so that is no longer associated with the original hardware device. The problem is that the cookie is not cleared, so that a call to `comedi_auto_unconfig()` from the low-level driver will still find it, detach it, clean it up and free it. Stop this problem occurring by always clearing the `hardware_device` cookie in the `struct comedi_dev_file_info` whenever the `COMEDI_DEVCONFIG` ioctl call is successful. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

staging: comedi: amplc_pc236: fix invalid register access during detach

2012-10-31T17:03:19+00:00

commit aaeb61a97b7159ebe30b18a422d04eeabfa8790b upstream. `pc236_detach()` is called by the comedi core if it attempted to attach a device and failed. `pc236_detach()` calls `pc236_intr_disable()` if the comedi device private data pointer (`devpriv`) is non-null. This test is insufficient as `pc236_intr_disable()` accesses hardware registers and the attach routine may have failed before it has saved their I/O base addresses. Fix it by checking `dev->iobase` is non-zero before calling `pc236_intr_disable()` as that means the I/O base addresses have been saved and the hardware registers can be accessed. It also implies the comedi device private data pointer is valid, so there is no need to check it. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

staging: comedi: fix memory leak for saved channel list

2012-10-07T15:32:24+00:00

commit c8cad4c89ee3b15935c532210ae6ebb5c0a2734d upstream. When `do_cmd_ioctl()` allocates memory for the kernel copy of a channel list, it frees any previously allocated channel list in `async->cmd.chanlist` and replaces it with the new one. However, if the device is ever removed (or "detached") the cleanup code in `cleanup_device()` in "drivers.c" does not free this memory so it is lost. A sensible place to free the kernel copy of the channel list is in `do_become_nonbusy()` as at that point the comedi asynchronous command associated with the channel list is no longer valid. Free the channel list in `do_become_nonbusy()` instead of `do_cmd_ioctl()` and clear the pointer to prevent it being freed more than once. Note that `cleanup_device()` could be called at an inappropriate time while the comedi device is open, but that's a separate bug not related to this this patch. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

staging: comedi: don't dereference user memory for INSN_INTTRIG

2012-10-07T15:32:24+00:00

commit 5d06e3df280bd230e2eadc16372e62818c63e894 upstream. `parse_insn()` is dereferencing the user-space pointer `insn->data` directly when handling the `INSN_INTTRIG` comedi instruction. It shouldn't be using `insn->data` at all; it should be using the separate `data` pointer passed to the function. Fix it. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

staging: comedi: jr3_pci: fix iomem dereference

2012-10-07T15:32:24+00:00

commit e1878957b4676a17cf398f7f5723b365e9a2ca48 upstream. Correct a direct dereference of I/O memory to use an appropriate I/O memory access function. Note that the pointer being dereferenced is not currently tagged with `__iomem` but I plan to correct that for 3.7. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman