Re: [PATCH v2 6/6] efi: respect the poisoned pages coming from previous kernel

[Kiryl Shutsemau]

On Fri, Aug 21, 2026 at 03:06:06AM -0700, Breno Leitao wrote:
> +	/* Reserve the table itself so it survives a further kexec. */
> +	memblock_reserve(PAGE_ALIGN_DOWN(ppm),
> +			 PAGE_ALIGN(ppm + sizeof(*pm) + bitmap_size) -
> +			 PAGE_ALIGN_DOWN(ppm));

Hm. I don't think it is enough.

On x86, kernel doesn't keep memblock around after boot (see
CONFIG_ARCH_KEEP_MEMBLOCK). Reserving in memblock exclude the memory
from page allocator. But kexec can place the image there.

For !CONFIG_ARCH_KEEP_MEMBLOCK, kexec uses walk_system_ram_res() that
looks into iomem_resource. And memblock does nothing to exclude the
memory from iomem_resource.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov