On Wed, Jan 8, 2025 at 8:04 AM Basharath Hussain Khaja
<bashar...@couthit.com> wrote:
>
> Hi,
>
> >> Thomas Weißschuh <thomas.weisssc...@linutronix.de> writes:
> >> > The members "start" and "end" of struct resource are of type
> >> > "resource_size_t" which can be 32bit wide.
> >> > Values read from OF however are always 64bit wide.
> >> >
> >> > Refactor the diff overflow checks into a helper function.
> >> > Also extend the checks to validate each calculation step.
> >> >
> >> > Signed-off-by: Thomas Weißschuh <thomas.weisssc...@linutronix.de>
> >> > ---
> >> > drivers/of/address.c | 45 ++++++++++++++++++++++++++-------------------
> >> > 1 file changed, 26 insertions(+), 19 deletions(-)
> >> >
> >> > diff --git a/drivers/of/address.c b/drivers/of/address.c
> >> > index 7e59283a4472..df854bb427ce 100644
> >> > --- a/drivers/of/address.c
> >> > +++ b/drivers/of/address.c
> >> > @@ -198,6 +198,25 @@ static u64 of_bus_pci_map(__be32 *addr, const
> >> > __be32 *range, int na, int ns,
> >> >
> >> > #endif /* CONFIG_PCI */
> >> >
> >> > +static int __of_address_resource_bounds(struct resource *r, u64 start,
> >> > u64 size)
> >> > +{
> >> > + u64 end = start;
> >> > +
> >> > + if (overflows_type(start, r->start))
> >> > + return -EOVERFLOW;
> >> > + if (size == 0)
> >> > + return -EOVERFLOW;
> >> > + if (check_add_overflow(end, size - 1, &end))
> >> > + return -EOVERFLOW;
> >> > + if (overflows_type(end, r->end))
> >> > + return -EOVERFLOW;
> >>
> >> This breaks PCI on powerpc qemu. Part of the PCI probe reads a resource
> >> that's zero sized, which used to succeed but now fails due to the size
> >> check above.
> >>
> >> The diff below fixes it for me.
> >
> > I fixed it up with your change.
>
>
> This commit is breaking Ethernet functionality on the TI AM57xx platform due
> to zero byte SRAM block size allocation during initialization. Prior to this
> patch, zero byte block sizes were handled properly.
What driver and where exactly?
Rob
