On Mon, 2015-08-17 at 12:22 +0100, Will Deacon wrote:
> Hi Mark,
>
> On Sun, Aug 16, 2015 at 09:49:27PM +0100, Mark Salter wrote:
> > The use of mem= could leave part or all of the initrd outside of
> > the kernel linear map. This will lead to an error when unpacking
> > the initrd and a probable failure to boot. This patch catches that
> > situation and relocates the initrd to be fully within the linear
> > map.
> >
> > Signed-off-by: Mark Salter <msalter@xxxxxxxxxx>
> > ---
> > arch/arm64/kernel/setup.c | 59
> > +++++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 59 insertions(+)
> >
> > diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> > index f3067d4..5f45fd9 100644
> > --- a/arch/arm64/kernel/setup.c
> > +++ b/arch/arm64/kernel/setup.c
> > @@ -359,6 +359,64 @@ static void __init
> > request_standard_resources(void)
> > }
> > }
> >
> > +#ifdef CONFIG_BLK_DEV_INITRD
> > +/*
> > + * Relocate initrd if it is not completely within the linear mapping.
> > + * This would be the case if mem= cuts out all or part of it.
> > + */
> > +static void __init relocate_initrd(void)
> > +{
> > + phys_addr_t orig_start = __virt_to_phys(initrd_start);
> > + phys_addr_t orig_end = __virt_to_phys(initrd_end);
>
> Any particular reason to use the __* variants here?
To avoid need to cast initrd_{start,end} to pointer.
>
> > + phys_addr_t ram_end = memblock_end_of_DRAM();
> > + phys_addr_t new_start;
> > + unsigned long size, to_free = 0;
> > + void *dest;
> > +
> > + if (orig_end <= ram_end)
> > + return;
> > +
> > + /* Note if any of original initrd will freeing below */
>
> The comment doesn't make sense.
No it doesn't.
>
> > + if (orig_start < ram_end)
> > + to_free = ram_end - orig_start;
> > +
> > + size = orig_end - orig_start;
> > +
> > + /* initrd needs to be relocated completely inside linear
> > mapping */
> > + new_start = memblock_find_in_range(0, PFN_PHYS(max_pfn),
> > + size, PAGE_SIZE);
> > + if (!new_start)
> > + panic("Cannot relocate initrd of size %ld\n", size);
> > + memblock_reserve(new_start, size);
> > +
> > + initrd_start = __phys_to_virt(new_start);
> > + initrd_end = initrd_start + size;
> > +
> > + pr_info("Moving initrd from [%llx-%llx] to [%llx-%llx]\n",
> > + orig_start, orig_start + size - 1,
> > + new_start, new_start + size - 1);
> > +
> > + dest = (void *)initrd_start;
> > +
> > + if (to_free) {
> > + memcpy(dest, (void *)__phys_to_virt(orig_start),
> > to_free);
> > + dest += to_free;
> > + }
> > +
> > + copy_from_early_mem(dest, orig_start + to_free, size -
> > to_free);
> > +
> > + if (to_free) {
> > + pr_info("Freeing original RAMDISK from [%llx-%llx]\n",
> > + orig_start, orig_start + to_free - 1);
> > + memblock_free(orig_start, to_free);
> > + }
> > +}
> > +#else
> > +static inline void __init reserve_initrd(void)
>
> relocate_initrd ?
Yes
Thanks, will fix that and the comment.
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