comedi: amplc_dio200: Add sanity checks for I/O base address

The "amplc_dio200" driver uses an admin-supplied configuration option
(`it->options[0]`) to configure the I/O port base address of a supported
board (PC212E, PC214E, PC215E, PC218E, or PC272E).  It currently allows
any base address to be configured but the hardware only supports base
addresses (set by on-board DIP switches) in the range 0 to 0xFE0 on
32-byte boundaries.  (Technically, the DIP switches allow 16-byte
boundaries, but I do not think that is advisable given that the boards
decode a 32-byte address range.)

Add a sanity check to ensure the device is not configured at an
unsupported base address.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://patch.msgid.link/20260130170416.49994-7-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/comedi/drivers/amplc_dio200.c b/drivers/comedi/drivers/amplc_dio200.c
index 4544bcdd8a708129dadf0fc76c330f0f68ac63a2..8b1cbc3d24e560f477f3513831ddbb79ff1af266 100644 (file)
--- a/drivers/comedi/drivers/amplc_dio200.c
+++ b/drivers/comedi/drivers/amplc_dio200.c
@@ -242,7 +242,8 @@ static int dio200_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 {
        int ret;
 
-       ret = comedi_request_region(dev, it->options[0], 0x20);
+       ret = comedi_check_request_region(dev, it->options[0], 0x20,
+                                         0, 0xfff, 0x20);
        if (ret)
                return ret;