On Mon, Aug 17, 2015 at 06:01:06PM +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 | 62 +++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 62 insertions(+)
Looks good to me:
Acked-by: Will Deacon <will.deacon@xxxxxxx>
This series should replace the version that Andrew has currently got in
linux-next.
Will
> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index f3067d4..40a894e 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -359,6 +359,67 @@ 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);
> + 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;
> +
> + /*
> + * Any of the original initrd which overlaps the linear map should
> + * be freed after relocating.
> + */
> + 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 relocate_initrd(void)
> +{
> +}
> +#endif
> +
> u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
>
> void __init setup_arch(char **cmdline_p)
> @@ -392,6 +453,7 @@ void __init setup_arch(char **cmdline_p)
> acpi_boot_table_init();
>
> paging_init();
> + relocate_initrd();
> request_standard_resources();
>
> early_ioremap_reset();
> --
> 2.4.3
>
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