linux-stable.git/drivers/staging/comedi, branch v3.16.78

staging: comedi: dt3000: Fix rounding up of timer divisor

2019-11-22T15:57:15+00:00

commit 8e2a589a3fc36ce858d42e767c3bcd8fc62a512b upstream.

`dt3k_ns_to_timer()` determines the prescaler and divisor to use to
produce a desired timing period.  It is influenced by a rounding mode
and can round the divisor up, down, or to the nearest value.  However,
the code for rounding up currently does the same as rounding down!  Fix
ir by using the `DIV_ROUND_UP()` macro to calculate the divisor when
rounding up.

Also, change the types of the `divider`, `base` and `prescale` variables
from `int` to `unsigned int` to avoid mixing signed and unsigned types
in the calculations.

Also fix a typo in a nearby comment: "improvment" => "improvement".

Signed-off-by: Ian Abbott 
Link: https://lore.kernel.org/r/20190812120814.21188-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

staging: comedi: dt3000: Fix signed integer overflow 'divider * base'

2019-11-22T15:57:15+00:00

commit b4d98bc3fc93ec3a58459948a2c0e0c9b501cd88 upstream.

In `dt3k_ns_to_timer()` the following lines near the end of the function
result in a signed integer overflow:

	prescale = 15;
	base = timer_base * (1 << prescale);
	divider = 65535;
	*nanosec = divider * base;

(`divider`, `base` and `prescale` are type `int`, `timer_base` and
`*nanosec` are type `unsigned int`.  The value of `timer_base` will be
either 50 or 100.)

The main reason for the overflow is that the calculation for `base` is
completely wrong.  It should be:

	base = timer_base * (prescale + 1);

which matches an earlier instance of this calculation in the same
function.

Reported-by: David Binderman 
Signed-off-by: Ian Abbott 
Link: https://lore.kernel.org/r/20190812111517.26803-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

staging: comedi: dt282x: fix a null pointer deref on interrupt

2019-09-23T20:12:18+00:00

commit b8336be66dec06bef518030a0df9847122053ec5 upstream.

The interrupt handler `dt282x_interrupt()` causes a null pointer
dereference for those supported boards that have no analog output
support.  For these boards, `dev->write_subdev` will be `NULL` and
therefore the `s_ao` subdevice pointer variable will be `NULL`.  In that
case, the following call near the end of the interrupt handler results
in a null pointer dereference:

	cfc_handle_events(dev, s_ao);

[ Upstream equivalent:
	comedi_handle_events(dev, s_ao);
  -- IA ]

Fix it by only calling the above function if `s_ao` is valid.

(There are other uses of `s_ao` by the interrupt handler that may or may
not be reached depending on values of hardware registers.  Trust that
they are reliable for now.)

Fixes: f21c74fa4cfe ("staging: comedi: dt282x: use cfc_handle_events()")
Signed-off-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

staging: comedi: vmk80xx: Fix possible double-free of ->usb_rx_buf

2019-08-13T11:39:08+00:00

commit 663d294b4768bfd89e529e069bffa544a830b5bf upstream.

`vmk80xx_alloc_usb_buffers()` is called from `vmk80xx_auto_attach()` to
allocate RX and TX buffers for USB transfers.  It allocates
`devpriv->usb_rx_buf` followed by `devpriv->usb_tx_buf`.  If the
allocation of `devpriv->usb_tx_buf` fails, it frees
`devpriv->usb_rx_buf`,  leaving the pointer set dangling, and returns an
error.  Later, `vmk80xx_detach()` will be called from the core comedi
module code to clean up.  `vmk80xx_detach()` also frees both
`devpriv->usb_rx_buf` and `devpriv->usb_tx_buf`, but
`devpriv->usb_rx_buf` may have already been freed, leading to a
double-free error.  Fix it by removing the call to
`kfree(devpriv->usb_rx_buf)` from `vmk80xx_alloc_usb_buffers()`, relying
on `vmk80xx_detach()` to free the memory.

Signed-off-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

staging: comedi: vmk80xx: Fix use of uninitialized semaphore

2019-08-13T11:39:08+00:00

commit 08b7c2f9208f0e2a32159e4e7a4831b7adb10a3e upstream.

If `vmk80xx_auto_attach()` returns an error, the core comedi module code
will call `vmk80xx_detach()` to clean up.  If `vmk80xx_auto_attach()`
successfully allocated the comedi device private data,
`vmk80xx_detach()` assumes that a `struct semaphore limit_sem` contained
in the private data has been initialized and uses it.  Unfortunately,
there are a couple of places where `vmk80xx_auto_attach()` can return an
error after allocating the device private data but before initializing
the semaphore, so this assumption is invalid.  Fix it by initializing
the semaphore just after allocating the private data in
`vmk80xx_auto_attach()` before any other errors can be returned.

I believe this was the cause of the following syzbot crash report
:

usb 1-1: config 0 has no interface number 0
usb 1-1: New USB device found, idVendor=10cf, idProduct=8068, bcdDevice=e6.8d
usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
usb 1-1: config 0 descriptor??
vmk80xx 1-1:0.117: driver 'vmk80xx' failed to auto-configure device.
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.1.0-rc4-319354-g9a33b36 #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xe8/0x16e lib/dump_stack.c:113
 assign_lock_key kernel/locking/lockdep.c:786 [inline]
 register_lock_class+0x11b8/0x1250 kernel/locking/lockdep.c:1095
 __lock_acquire+0xfb/0x37c0 kernel/locking/lockdep.c:3582
 lock_acquire+0x10d/0x2f0 kernel/locking/lockdep.c:4211
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x44/0x60 kernel/locking/spinlock.c:152
 down+0x12/0x80 kernel/locking/semaphore.c:58
 vmk80xx_detach+0x59/0x100 drivers/staging/comedi/drivers/vmk80xx.c:829
 comedi_device_detach+0xed/0x800 drivers/staging/comedi/drivers.c:204
 comedi_device_cleanup.part.0+0x68/0x140 drivers/staging/comedi/comedi_fops.c:156
 comedi_device_cleanup drivers/staging/comedi/comedi_fops.c:187 [inline]
 comedi_free_board_dev.part.0+0x16/0x90 drivers/staging/comedi/comedi_fops.c:190
 comedi_free_board_dev drivers/staging/comedi/comedi_fops.c:189 [inline]
 comedi_release_hardware_device+0x111/0x140 drivers/staging/comedi/comedi_fops.c:2880
 comedi_auto_config.cold+0x124/0x1b0 drivers/staging/comedi/drivers.c:1068
 usb_probe_interface+0x31d/0x820 drivers/usb/core/driver.c:361
 really_probe+0x2da/0xb10 drivers/base/dd.c:509
 driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
 __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
 bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
 __device_attach+0x223/0x3a0 drivers/base/dd.c:844
 bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
 device_add+0xad2/0x16e0 drivers/base/core.c:2106
 usb_set_configuration+0xdf7/0x1740 drivers/usb/core/message.c:2021
 generic_probe+0xa2/0xda drivers/usb/core/generic.c:210
 usb_probe_device+0xc0/0x150 drivers/usb/core/driver.c:266
 really_probe+0x2da/0xb10 drivers/base/dd.c:509
 driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
 __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
 bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
 __device_attach+0x223/0x3a0 drivers/base/dd.c:844
 bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
 device_add+0xad2/0x16e0 drivers/base/core.c:2106
 usb_new_device.cold+0x537/0xccf drivers/usb/core/hub.c:2534
 hub_port_connect drivers/usb/core/hub.c:5089 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
 port_event drivers/usb/core/hub.c:5350 [inline]
 hub_event+0x138e/0x3b00 drivers/usb/core/hub.c:5432
 process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
 worker_thread+0x9b/0xe20 kernel/workqueue.c:2415
 kthread+0x313/0x420 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Reported-by: syzbot+54c2f58f15fe6876b6ad@syzkaller.appspotmail.com
Signed-off-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

staging: comedi: ni_mio_common: protect register write overflow

2019-02-11T17:53:30+00:00

commit 1cbca5852d6c16e85a21487a15d211195aacd4a1 upstream.

Fixes two problems introduced as early as
commit 03aef4b6dc12  ("Staging: comedi: add ni_mio_common code"):
(1) Ensures that the last four bits of NISTC_RTSI_TRIGB_OUT_REG register is
    not unduly overwritten on e-series devices.  On e-series devices, the
    first three of the last four bits are reserved.  The last bit defines
    the output selection of the RGOUT0 pin, otherwise known as
    RTSI_Sub_Selection.  For m-series devices, these last four bits are
    indeed used as the output selection of the RTSI7 pin (and the
    RTSI_Sub_Selection bit for the RGOUT0 pin is moved to the
    RTSI_Trig_Direction register.
(2) Allows all 4 RTSI_BRD lines to be treated as valid sources for RTSI
    lines.

This patch also cleans up the ni_get_rtsi_routing command for readability.

Fixes: 03aef4b6dc12  ("Staging: comedi: add ni_mio_common code")
Signed-off-by: Spencer E. Olson 
Reviewed-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.16:
 - Use NI_RTSI_OUTPUT_RTSI_BRD_0 + n instead of NI_RTSI_OUTPUT_RTSI_BRD(n)
 - Use num_configurable_rtsi_channels() instead of NISTC_RTSI_TRIG_NUM_CHAN()
 - Use old_RTSI_clock_channel instead of NISTC_RTSI_TRIG_OLD_CLK_CHAN
 - Adjust context]
Signed-off-by: Ben Hutchings

staging: comedi: quatech_daqp_cs: fix no-op loop daqp_ao_insn_write()

2019-02-11T17:53:15+00:00

commit 1376b0a2160319125c3a2822e8c09bd283cd8141 upstream.

There is a '>' vs '<' typo so this loop is a no-op.

Fixes: d35dcc89fc93 ("staging: comedi: quatech_daqp_cs: fix daqp_ao_insn_write()")
Signed-off-by: Dan Carpenter 
Reviewed-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

staging: comedi: quatech_daqp_cs: use comedi_timeout() in ao (*insn_write)

2019-02-11T17:53:15+00:00

commit e031642eccc040648b09cfc7d632e2e8d0b6f94f upstream.

The data link between the D/A data port and the D/A converter is a serial
link. The serial link requires about 8ms to complete a transfer. Use the
comedi_timeout() helper to ensure that there is not a previous transfer
still happening before trying to write new data to the channel.

Signed-off-by: H Hartley Sweeten 
Reviewed-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman 
[ija: Backported to 3.16: No 'readback' member in subdevice.]
Signed-off-by: Ian Abbott 
Signed-off-by: Ben Hutchings

staging: comedi: quatech_daqp_cs: fix bug in daqp_ao_insn_write()

2019-02-11T17:53:15+00:00

commit e024181b02ed6b833358bede3f2d0c52cb5fb6bc upstream.

The comedi core expects (*insn_write) functions to write insn->n values
to the hardware and return the number of values written.

Currently, this function only writes the first value. Fix it to work
like the core expects.

Signed-off-by: H Hartley Sweeten 
Reviewed-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

staging: comedi: fix clean-up of comedi_class in comedi_init()

2017-10-12T14:27:52+00:00

commit a9332e9ad09c2644c99058fcf6ae2f355e93ce74 upstream.

There is a clean-up bug in the core comedi module initialization
functions, `comedi_init()`.  If the `comedi_num_legacy_minors` module
parameter is non-zero (and valid), it creates that many "legacy" devices
and registers them in SysFS.  A failure causes the function to clean up
and return an error.  Unfortunately, it fails to destroy the "comedi"
class that was created earlier.  Fix it by adding a call to
`class_destroy(comedi_class)` at the appropriate place in the clean-up
sequence.

Signed-off-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings