comedi: pcmuio: Add sanity checks for I/O base address

The "pcmmio" driver uses an admin-supplied configuration option
(`it->options[0]`) to configure the I/O port base address of a
PCM-UIO48A or PCM-UIO96A board.  It will probably work with the later
PCM-UIO48C and PCM-UIO96C boards.  It currently allows any base address
to be configured but the hardware only supports base addresses
(configured by on-board jumpers) in the range 0 to 0xFFF0 on 16-byte
boundaries (for PCM-UIO48C) or 0 to 0xFFE0 on 32-byte boundaries (for
PCM-UIO96C).  (The PCM-UIO48A supports base addresses up to 0xFF0 and
the PCI-UIO96A supports base addresses up to 0x7E0.)

Add a sanity check to ensure the device is not configured at an
unsupported base address (allowing for the extended range of the "C"
models).

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://patch.msgid.link/20260130170416.49994-44-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/comedi/drivers/pcmuio.c b/drivers/comedi/drivers/pcmuio.c
index 33b24dbbb919959f6174edf0cb2c85c807ce298a..0995911a3ea304055cb6a7694967809510cc0435 100644 (file)
--- a/drivers/comedi/drivers/pcmuio.c
+++ b/drivers/comedi/drivers/pcmuio.c
@@ -521,11 +521,12 @@ static int pcmuio_attach(struct comedi_device *dev, struct comedi_devconfig *it)
        const struct pcmuio_board *board = dev->board_ptr;
        struct comedi_subdevice *s;
        struct pcmuio_private *devpriv;
+       unsigned int io_len = board->num_asics * PCMUIO_ASIC_IOSIZE;
        int ret;
        int i;
 
-       ret = comedi_request_region(dev, it->options[0],
-                                   board->num_asics * PCMUIO_ASIC_IOSIZE);
+       ret = comedi_check_request_region(dev, it->options[0], io_len,
+                                         0, 0xffff, io_len);
        if (ret)
                return ret;