[PATCH v3 1/5] lib: utils/irqchip: plic: Fix the off-by-one error in priority save/restore helpers

[Anup Patel]

On Mon, Dec 12, 2022 at 12:10 PM Samuel Holland <samuel at sholland.org> wrote:
>
> On 12/11/22 04:18, Bin Meng wrote:
> > On Sun, Dec 11, 2022 at 6:08 PM Andreas Schwab <schwab at linux-m68k.org> wrote:
> >>
> >> On Dez 11 2022, Bin Meng wrote:
> >>
> >>> diff --git a/lib/utils/irqchip/plic.c b/lib/utils/irqchip/plic.c
> >>> index 73d7788..4df9020 100644
> >>> --- a/lib/utils/irqchip/plic.c
> >>> +++ b/lib/utils/irqchip/plic.c
> >>> @@ -38,13 +38,13 @@ static void plic_set_priority(const struct plic_data *plic, u32 source, u32 val)
> >>>
> >>>  void plic_priority_save(const struct plic_data *plic, u8 *priority)
> >>>  {
> >>> -     for (u32 i = 0; i < plic->num_src; i++)
> >>> +     for (u32 i = 1; i <= plic->num_src; i++)
> >>>               priority[i] = plic_get_priority(plic, i);
> >>
> >> That needs to adjust the index into the priority array.
> >
> > Does that help anything? It just confuses people more.
> >
> > I added function parameter descriptions in patch 2 to make it crystal
> > clear, that the priority array needs to include interrupt source 0.
>
> To me, it is more confusing that when I ask to save the priority for N
> sources, I need to allocate an array with >N elements. And leaving array
> element 0 unused wastes memory.

This can be a separate improvement patch.

Regards,
Anup

>
> Regards,
> Samuel
>
>
> --
> opensbi mailing list
> opensbi at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/opensbi