On Mon, Oct 29, 2018 at 12:54 PM <peng.hao2@xxxxxxxxxx> wrote:
>
> >On Mon, Oct 29, 2018 at 5:22 AM Peng Hao <peng.hao2@xxxxxxxxxx> wrote:
> >>
> >> On some architectures (e.g. arm64), it's preferable to use MMIO, since
> >> this can be used standalone. Add MMIO support to the pvpanic driver.
> >
> >> pvpanic_walk_resources(struct acpi_resource *res, void *context)
> >> {
> >> + struct acpi_resource_fixed_memory32 *fixmem32;
> >> +
> >> switch (res->type) {
> >> case ACPI_RESOURCE_TYPE_END_TAG:
> >> return AE_OK;
> >>
> >> case ACPI_RESOURCE_TYPE_IO:
> >> - port = res->data.io.minimum;
> >> + base = (void __iomem *) ioport_map(res->data.io.minimum, 1);
> >> + return AE_OK;
> >> +
> >> + case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
> >> + fixmem32 = &res->data.fixed_memory32;
> >> + base = ioremap(fixmem32->address, fixmem32->address_length);
> >> return AE_OK;
> >
> >Ouch. Sorry, I forgot to look at this previously.
> >
> >This should be converted to use
> >acpi_dev_resource_io()
> >acpi_dev_resource_memory()
> >
> another question, here:
> iounmap(base) and base may be a ioport. I read x86 code for iounmap that checked the base.
> so I think it is safe for x86. But I'm not sure if other architectures using ioport are also secure
> in the same way of processing.
> Do you have any suggestions?
I would consider it as a bug if on some architectures iounmap() is not
able to take a base got from ioport_map().
--
With Best Regards,
Andy Shevchenko
