linux/drivers/staging/comedi, branch v3.7.7

staging: comedi: comedi_test: fix race when cancelling command

2013-01-17T16:46:35Z

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: Kconfig: COMEDI_NI_AT_A2150 should select COMEDI_FC

2013-01-17T16:46:35Z

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

2013-01-17T16:46:31Z

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

2013-01-17T16:46:26Z

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: ni_labpc: fix possible NULL deref during detach

2012-10-22T18:46:35Z

`labpc_common_detach()` is called by the comedi core to clean up if either `labpc_attach()` (including the one in the "ni_labpc_cs" module) or `labpc_attach_pci()` returns an error. It assumes the `thisboard` macro (expanding to `((struct labpc_board_struct *)dev->board_ptr)`) is non-null. This is a valid assumption if `labpc_attach()` fails, but not if `labpc_attach_pci()` fails, leading to a possible NULL pointer dereference. Check `thisboard` at the top of `labpc_common_detach()` and return early if it is `NULL`. This is okay because the only other thing that could have been allocated is `dev->private` and that is freed by the comedi core, not by this function. Cc: # 3.6.x Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

staging: comedi: das08: fix possible NULL deref during detach

2012-10-22T18:46:35Z

`das08_detach()` is called by the comedi core to clean up if either `das08_attach()` or `das08_attach_pci()` returns an error. It sets `thisboard` to the return value of `comedi_board(dev)` and assumes it is non-null. This is a valid assumption if `das08_attach()` fails, but not if `das08_attach_pci()` fails, leading to a possible NULL pointer dereference. Check `thisboard` at the top of `das08_detach()` and return early if it is `NULL`. This is okay because the only other thing that could have been allocated is `dev->private` and that is freed by the comedi core, not by this function. Cc: # 3.6.x Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

staging: comedi: amplc_pc263: fix possible NULL deref during detach

2012-10-22T18:46:35Z

`pc263_detach()` is called by the comedi core to clean up if either `pc263_attach()` or `pc263_attach_pci()` returns an error. It sets `thisboard` to the return value of `comedi_board(dev)` and assumes it is non-null. This is a valid assumption if `pc263_attach()` fails, but not if `pc263_attach_pci()` fails, leading to a possible NULL pointer dereference. Check `thisboard` at the top of `pc263_detach()` and return early if it is `NULL`. This is okay because no other resources need cleaning up in this case. Cc: # 3.6.x Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

staging: comedi: amplc_pc236: fix possible NULL deref during detach

2012-10-22T18:46:35Z

`pc236_detach()` is called by the comedi core to clean up if either `pc236_attach()` or `pc236_attach_pci()` returns an error. It sets `thisboard` to the return value of `comedi_board(dev)` and assumes it is non-null. This is a valid assumption if `pc236_attach()` fails, but not if `pc236_attach_pci()` fails, leading to a possible NULL pointer dereference. Check `thisboard` at the top of `pc236_detach()` and return early if it is `NULL`. This is okay because the only other thing that could have been allocated is `dev->private` and that is freed by the comedi core, not by this function. Cc: # 3.6.x Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

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

2012-10-22T18:46:35Z

`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. Cc: # 3.5.x, 3.6.x Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

staging: comedi: amplc_dio200: fix possible NULL deref during detach

2012-10-22T18:46:35Z

`dio200_detach()` is called by the comedi core to clean up if either `dio200_attach()` or `dio200_attach_pci()` return an error. It assigns `thisboard` to the return value of `comedi_board(dev)` and assumes it is non-null. In the case of a previous call to `dio200_attach()` it won't be `NULL` because the comedi core will have pointed it to one of the elements of `dio200_boards[]`, but in the case of a previous call to `dio200_attach_pci()` it could be `NULL`, leading to a null pointer dereference. Check that `thisboard` is valid at the top of `dio200_detach()` and return early if it is `NULL`. This is okay because the only other thing that could have been allocated is `dev->private` and that is freed by the comedi core, not by this function. Cc: # 3.6.x Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman