On Wed, 27 Aug 2014 13:08:51 +0200, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> Hi Grant,
>
> On Wed, Aug 27, 2014 at 12:30 PM, Grant Likely <grant.likely@xxxxxxxxxx> wrote:
> > On Wed, 20 Aug 2014 17:10:31 +0200, Geert Uytterhoeven <geert+renesas@xxxxxxxxx> wrote:
> >> If a memory block is not aligned to PAGE_SIZE, its base address must be
> >> rounded up, not down, and its size must be reduced.
> >>
> >> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> >
> > Looks reasonable. What is the situation that exposed this problem?
>
> When ARM switched from arm_add_memory() to early_init_dt_add_memory_arch()
> for DT-based platforms, I just noticed this when comparing the two
> implementations.
>
> I don't know if it triggers in the wild.
>
> > Should size be checked for page alignment also?
>
> Size is already rounded down if it's not page aligned, cfr. the context below.
Indeed it is. Silly me. Applied, thanks.
g.
>
> >> ---
> >> drivers/of/fdt.c | 6 +++++-
> >> 1 file changed, 5 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> >> index f46a24ffa3fe..95fa81b8ca19 100644
> >> --- a/drivers/of/fdt.c
> >> +++ b/drivers/of/fdt.c
> >> @@ -928,7 +928,11 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
> >> void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
> >> {
> >> const u64 phys_offset = __pa(PAGE_OFFSET);
> >> - base &= PAGE_MASK;
> >> +
> >> + if (!PAGE_ALIGNED(base)) {
> >> + size -= PAGE_SIZE - (base & ~PAGE_MASK);
> >> + base = PAGE_ALIGN(base);
> >> + }
> >> size &= PAGE_MASK;
> >>
> >> if (base > MAX_PHYS_ADDR) {
> >> --
> >> 1.9.1
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
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