Re: [PATCH v7 1/3] efi/x86: Fix EFI memory map corruption with kexec

[Dave Young]

> >         ...
> >         if (efi.memmap.flags & (EFI_MEMMAP_MEMBLOCK | EFI_MEMMAP_SLAB)) {
> >                 __efi_memmap_free(efi.memmap.phys_map,
> >                                 efi.memmap.desc_size * efi.memmap.nr_map, efi.memmap.flags);
> >         }
>
> From your debugging the memmap should not be freed.  This piece of
> code was added in below commit,  added Dan Williams in cc list:
> commit f0ef6523475f18ccd213e22ee593dfd131a2c5ea
> Author: Dan Williams <dan.j.williams@xxxxxxxxx>
> Date:   Mon Jan 13 18:22:44 2020 +0100
>
>     efi: Fix efi_memmap_alloc() leaks
>
>     With efi_fake_memmap() and efi_arch_mem_reserve() the efi table may be
>     updated and replaced multiple times. When that happens a previous
>     dynamically allocated efi memory map can be garbage collected. Use the
>     new EFI_MEMMAP_{SLAB,MEMBLOCK} flags to detect when a dynamically
>     allocated memory map is being replaced.
>

Dan, probably those regions should be freed only for "fake" memmap?