Re: [PATCH] PM: domains: fix overflow in genpd_parse_state

[Yi-ming Tseng]

Oh I just found there is a similar patch from Nikita Zhandarovich
and it will be applied in v6.5. I think we can drop this patch. Thanks
and sorry for duplicated patches.

The patch from Nikita Zhandarovich and the discussion:
https://lore.kernel.org/all/CAJZ5v0gx7bD9EZKPQWyAAZ6hSKjK4hr-nkrJu84HEK-g2AMAaw@xxxxxxxxxxxxxx/

Thanks again.

On Sat, Jun 17, 2023 at 1:44 AM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
>
> On Tue, May 30, 2023 at 1:42 PM YiMing Tseng <yimingtseng@xxxxxxxxxx> wrote:
> >
> > Add type casters to prevent 32-bit overflow before assigning to s64
> > variables. It allows full 32-bit range support for latency and
> > residency.
>
> OK, but is it really a practical problem?
>
> Ulf, what do you think?
>
> > Signed-off-by: YiMing Tseng <yimingtseng@xxxxxxxxxx>
> > ---
> >  drivers/base/power/domain.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> > index 32084e38b73d..26a04cd8d8dc 100644
> > --- a/drivers/base/power/domain.c
> > +++ b/drivers/base/power/domain.c
> > @@ -2939,10 +2939,10 @@ static int genpd_parse_state(struct genpd_power_state *genpd_state,
> >
> >         err = of_property_read_u32(state_node, "min-residency-us", &residency);
> >         if (!err)
> > -               genpd_state->residency_ns = 1000 * residency;
> > +               genpd_state->residency_ns = (s64)1000 * residency;
> >
> > -       genpd_state->power_on_latency_ns = 1000 * exit_latency;
> > -       genpd_state->power_off_latency_ns = 1000 * entry_latency;
> > +       genpd_state->power_on_latency_ns = (s64)1000 * exit_latency;
> > +       genpd_state->power_off_latency_ns = (s64)1000 * entry_latency;
> >         genpd_state->fwnode = &state_node->fwnode;
> >
> >         return 0;
> > --