commit 857a661020a2de3a0304edf33ad656abee100891 upstream.

Commit 0557344e2149 ("staging: comedi: ni_mio_common: fix local var for
32-bit read") changed the type of local variable `d` from `unsigned
short` to `unsigned int` to fix a bug introduced in
commit 9c340ac934db ("staging: comedi: ni_stc.h: add read/write
callbacks to struct ni_private") when reading AI data for NI PCI-6110
and PCI-6111 cards.  Unfortunately, other parts of the function rely on
the variable being `unsigned short` when an offset value in local
variable `signbits` is added to `d` before writing the value to the
`data` array:

			d += signbits;
		  	data[n] = d;

The `signbits` variable will be non-zero in bipolar mode, and is used to
convert the hardware's 2's complement, 16-bit numbers to Comedi's
straight binary sample format (with 0 representing the most negative
voltage).  This breaks because `d` is now 32 bits wide instead of 16
bits wide, so after the addition of `signbits`, `data[n]` ends up being
set to values above 65536 for negative voltages.  This affects all
supported "E series" cards except PCI-6143 (and PXI-6143). Fix it by
ANDing the value written to the `data[n]` with the mask 0xffff.

Fixes: 0557344e2149 ("staging: comedi: ni_mio_common: fix local var for 32-bit read")
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 655c4d442d1213b617926cc6d54e2a9a793fb46b upstream.

For NI M Series cards, the Comedi `insn_read` handler for the AI
subdevice is broken due to ANDing the value read from the AI FIFO data
register with an incorrect mask.  The incorrect mask clears all but the
most significant bit of the sample data.  It should preserve all the
sample data bits.  Correct it.

Fixes: 817144ae7fda ("staging: comedi: ni_mio_common: remove unnecessary use of 'board->adbits'")
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 55abe8165f31ffb83ce8b24da959b61362dca4c4 upstream.

`ni_tio_clock_period_ps()` used to return the clock period in
picoseconds, and had a `BUG()` call for invalid cases.  It was changed
to pass the clock period back via a pointer parameter and return an
error for the invalid cases.  Unfortunately the code to handle
user-specified clock sources with user-specified clock period is still
returning the clock period the old way, which can lead to the caller not
getting the clock period, or seeing an unexpected error.  Fix it by
passing the clock period via the pointer parameter and returning `0`.

Fixes: b42ca86ad605 ("staging: comedi: ni_tio: remove BUG() checks for ni_tio_get_clock_src()")
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit ebb657babfa9 ("staging: comedi: ni_mio_common: clarify the
cmd->start_arg validation and use") introduced a backwards compatibility
issue in the use of asynchronous commands on the AO subdevice when
`start_src` is `TRIG_EXT`.  Valid values for `start_src` are `TRIG_INT`
(for internal, software trigger), and `TRIG_EXT` (for external trigger).
When set to `TRIG_EXT`.  In both cases, the driver relies on an
internal, software trigger to set things up (allowing the user
application to write sufficient samples to the data buffer before the
trigger), so it acts as a software "pre-trigger" in the `TRIG_EXT` case.
The software trigger is handled by `ni_ao_inttrig()`.

Prior to the above change, when `start_src` was `TRIG_INT`, `start_arg`
was required to be 0, and `ni_ao_inttrig()` checked that the software
trigger number was also 0.  After the above change, when `start_src` was
`TRIG_INT`, any value was allowed for `start_arg`, and `ni_ao_inttrig()`
checked that the software trigger number matched this `start_arg` value.
The backwards compatibility issue is that the internal trigger number
now has to match `start_arg` when `start_src` is `TRIG_EXT` when it
previously had to be 0.

Fix the backwards compatibility issue in `ni_ao_inttrig()` by always
allowing software trigger number 0 when `start_src` is something other
than `TRIG_INT`.

Thanks to Spencer Olson for reporting the issue.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reported-by: Spencer Olson <olsonse@umich.edu>
Fixes: ebb657babfa9 ("staging: comedi: ni_mio_common: clarify the cmd->start_arg validation and use")
Cc: stable <stable@vger.kernel.org>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Bitwise | has higher precedence than ?: so we need to add some
parenthesis for this to work as intended.

Fixes: 7c9574090d30 ('staging: comedi: dt2811: simplify A/D reference configuration')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The CMDF_ROUND_DOWN case falls through and so always returns -EINVAL.

Fixes: 14b93bb6bbf0 ("staging: comedi: adv_pci_dio: separate out PCI-1760 support")
Signed-off-by: Phil Turnbull <phil.turnbull@oracle.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

For counter subdevices, the `s->insn_write` handler is being set to the
wrong function, `ni_tio_insn_read()`.  It should be
`ni_tio_insn_write()`.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reported-by: Éric Piel <piel@delmic.com>
Fixes: 10f74377eec3 ("staging: comedi: ni_tio: make ni_tio_winsn() a
  proper comedi (*insn_write)"
Cc: <stable@vger.kernel.org> # 3.17+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 73e0e4dfed4c ("staging: comedi: comedi_test: fix timer lock-up")
fixed a lock-up in the timer routine `waveform_ai_timer()` (which was
called `waveform_ai_interrupt()` at the time) caused by
commit 240512474424 ("staging: comedi: comedi_test: use
comedi_handle_events()").  However, it introduced a race condition that
can result in the timer routine misbehaving, such as accessing freed
memory or dereferencing a NULL pointer.

73e0... changed the timer routine to do nothing unless a
`WAVEFORM_AI_RUNNING` flag was set, and changed `waveform_ai_cancel()`
to clear the flag and replace a call to `del_timer_sync()` with a call
to `del_timer()`.  `waveform_ai_cancel()` may be called from the timer
routine itself (via `comedi_handle_events()`), or from `do_cancel()`.
(`do_cancel()` is called as a result of a file operation (usually a
`COMEDI_CANCEL` ioctl command, or a release), or during device removal.)
When called from `do_cancel()`, the call to `waveform_ai_cancel()` is
followed by a call to `do_become_nonbusy()`, which frees up stuff for
the current asynchronous command under the assumption that it is now
safe to do so.  The race condition occurs when the timer routine
`waveform_ai_timer()` checks the `WAVEFORM_AI_RUNNING` flag just before
it is cleared by `waveform_ai_cancel()`, and is still running during the
call to `do_become_nonbusy()`.  In particular, it can lead to a NULL
pointer dereference:

BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffffc0c63add>] waveform_ai_timer+0x17d/0x290 [comedi_test]

That corresponds to this line in `waveform_ai_timer()`:

		unsigned int chanspec = cmd->chanlist[async->cur_chan];

but `do_become_nonbusy()` frees `cmd->chanlist` and sets it to `NULL`.

Fix the race by calling `del_timer_sync()` instead of `del_timer()` in
`waveform_ai_cancel()` when not in an interrupt context.  The only time
`waveform_ai_cancel()` is called in an interrupt context is when it is
called from the timer routine itself, via `comedi_handle_events()`.

There is no longer any need for the `WAVEFORM_AI_RUNNING` flag, so get
rid of it.

The bug was copied from the AI subdevice to the AO when support for
commands on the AO subdevice was added by commit 0cf55bbef2f9 ("staging:
comedi: comedi_test: implement commands on AO subdevice").  That
involves the timer routine `waveform_ao_timer()`, the comedi "cancel"
routine `waveform_ao_cancel()`, and the flag `WAVEFORM_AO_RUNNING`.  Fix
it in the same way as for the AI subdevice.

Fixes: 73e0e4dfed4c ("staging: comedi: comedi_test: fix timer lock-up")
Fixes: 0cf55bbef2f9 ("staging: comedi: comedi_test: implement commands
 on AO subdevice")
Reported-by: Éric Piel <piel@delmic.com>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: <stable@vger.kernel.org> # 4.4+
Cc: Éric Piel <piel@delmic.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

`daqboard2000_find_boardinfo()` is supposed to check if the
DaqBoard/2000 series model is supported, based on the PCI subvendor and
subdevice ID.  The current code is wrong as it is comparing the PCI
device's subdevice ID to an expected, fixed value for the subvendor ID.
It should be comparing the PCI device's subvendor ID to this fixed
value.  Correct it.

Fixes: 7e8401b23e7f ("staging: comedi: daqboard2000: add back
subsystem_device check")
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: <stable@vger.kernel.org> # 3.7+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Comedi uses 32-bit seconds for its timestamps, on both 32-bit and
64-bit machines. For all I can tell, this was originally meant as
a 'timespec', which would overflow in 2038 because of the use of
a signed 'long' on 32-bit machines, but it is now used as an
array of two unsigned 'lsampl_t' values in comedilib, which will
only overflow in 2106, on both 32-bit and 64-bit machines.

In an effort to get rid of all uses of 'struct timeval' in the kernel,
this replaces the internal code with a call to ktime_get_real_ts64()
and a comment at the location of the conversion.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>