diff options
| author | Ian Abbott <abbotti@mev.co.uk> | 2026-01-30 19:47:27 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-04-02 16:49:36 +0300 |
| commit | cb51837eeeddac2da41f4c202597c534bb9d8dc9 (patch) | |
| tree | 4e0fa21cc854fabca6c96d74a12eb44348e879d2 | |
| parent | 241cb8dee0f83856c728f4fe2c29e331386c92f2 (diff) | |
| download | linux-cb51837eeeddac2da41f4c202597c534bb9d8dc9.tar.xz | |
comedi: 8255: Add some I/O base address sanity checks
The "8255" driver allows a COMEDI device to be constructed from one or
more 8255 chips, each at an I/O port base address specified by the
admin-supplied configuration options (`it->options[]`). Currently, the
driver allows any I/O base addresses to be specified as long as the I/O
regions can be reserved, and it converts the specified `int` option
values holding the base address to `unsigned long`.
It doesn't make sense to allow base addresses that are not aligned to
4-byte boundaries because the hardware register addresses would not be
decoded properly, so add a check for valid alignment.
Convert the option values that specify the base addresses from `int` to
`unsigned int` instead of `unsigned long` so they end up the same on
32-bit and 64-bit systems.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://patch.msgid.link/20260130170416.49994-3-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/comedi/drivers/8255.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/comedi/drivers/8255.c b/drivers/comedi/drivers/8255.c index 5f70938b4477..ff45248ebb29 100644 --- a/drivers/comedi/drivers/8255.c +++ b/drivers/comedi/drivers/8255.c @@ -47,7 +47,7 @@ static int dev_8255_attach(struct comedi_device *dev, struct comedi_devconfig *it) { struct comedi_subdevice *s; - unsigned long iobase; + unsigned int iobase; int ret; int i; @@ -70,13 +70,15 @@ static int dev_8255_attach(struct comedi_device *dev, iobase = it->options[i]; /* - * __comedi_request_region() does not set dev->iobase. + * __comedi_check_request_region() does not set dev->iobase. * * For 8255 devices that are manually attached using * comedi_config, the 'iobase' is the actual I/O port - * base address of the chip. + * base address of the chip. It should be aligned on + * a 4-byte boundary. */ - ret = __comedi_request_region(dev, iobase, I8255_SIZE); + ret = __comedi_check_request_region(dev, iobase, I8255_SIZE, + 0, UINT_MAX, 4); if (ret) return ret; ret = subdev_8255_io_init(dev, s, iobase); |