Re: [PATCH v2 1/2] x86/efi: don't allocate memmap through memblock after mm_init()
From: Ingo Molnar
Date: Thu Jan 05 2017 - 02:42:58 EST
* Nicolai Stange <nicstange@xxxxxxxxx> wrote:
> Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> writes:
>
> > On Thu, 22 Dec, at 11:23:39AM, Nicolai Stange wrote:
> >> So, after memblock is gone, allocations should be done through the "normal"
> >> page allocator. Introduce a helper, efi_memmap_alloc() for this. Use
> >> it from efi_arch_mem_reserve() and from efi_free_boot_services() as well.
> >>
> >> Fixes: 4bc9f92e64c8 ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data")
> >> Signed-off-by: Nicolai Stange <nicstange@xxxxxxxxx>
>
> > Could you also modify efi_fake_memmap() to use your new
> > efi_memmap_alloc() function for consistency
>
> Sure.
>
> I'm planning to submit another set of patches addressing the (bounded)
> memmap leaking in anything calling efi_memmap_unmap() though. In the
> course of doing so, the memmap allocation sites will get touched anyway:
> I'll have to store some information about how the memmap's memory has
> been obtained.
Will that patch be intrusive?
If yes then we'll need to keep this a separate urgent patch to fix the v4.9
regression that Dan Williams reported. I can apply the fix to efi/urgent and get
it to Linus straight away if you guys agree.
Thanks,
Ingo