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Re: [tip regression] efi: Allow drivers to reserve boot services forever == toxic

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On Fri, 16 Sep, at 12:00:59PM, Mike Galbraith wrote:
> 
> Ok, here's the whole thing just in case.  Hope it's not too big.
 
[...]

> [    0.000000] esrt: Reserving ESRT space from 0x00000000def87998 to 0x00000000def879d0.

OK, that's 56 bytes and yet I realise that at no point in the
efi_mem_reserve() call path do we round up to the nearest page size
even though the EFI memory map only deals with EFI_PAGE_SIZE regions.

Could you try this patch?

-------->8--------

From a24b38999965808355c461f8490670266162eabf Mon Sep 17 00:00:00 2001
From: Matt Fleming <matt@codeblueprint.co.uk>
Date: Fri, 16 Sep 2016 15:12:47 +0100
Subject: [PATCH] x86/efi: Round EFI memmap reservations to EFI_PAGE_SIZE

Mike reported that his machine started rebooting during boot after,

  commit 8e80632fb23f ("efi/esrt: Use efi_mem_reserve() and avoid a kmalloc()")

The ESRT table on his machine is 56 bytes and at no point in the
efi_arch_mem_reserve() call path is that size rounded up to
EFI_PAGE_SIZE.

Since the EFI memory map only deals with whole pages, inserting an EFI
memory region with 56 bytes results in a new entry covering zero
pages, and completely screws up the calculations for the old regions
that were trimmed.

Round all sizes upwards to the nearest EFI_PAGE_SIZE boundary.

Additionally, efi_memmap_insert() expects the mem::range::end value to
be one less than the end address for the region.

Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
---
 arch/x86/platform/efi/quirks.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index f14b7a9da24b..e881b4b2ffd6 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -201,8 +201,10 @@ void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)
 		return;
 	}
 
+	size = round_up(size, EFI_PAGE_SIZE);
+
 	mr.range.start = addr;
-	mr.range.end = addr + size;
+	mr.range.end = addr + size - 1;
 	mr.attribute = md.attribute | EFI_MEMORY_RUNTIME;
 
 	num_entries = efi_memmap_split_count(&md, &mr.range);
-- 
2.9.3

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[tip regression]  efi: Allow drivers to reserve boot services  forever == toxic Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-09-16 08:10 +0200
  Re: [tip regression]  efi: Allow drivers to reserve boot services  forever == toxic Matt Fleming <matt@codeblueprint.co.uk> - 2016-09-16 11:40 +0200
    Re: [tip regression]  efi: Allow drivers to reserve boot services  forever == toxic Matt Fleming <matt@codeblueprint.co.uk> - 2016-09-16 16:40 +0200
      Re: [tip regression]  efi: Allow drivers to reserve boot services  forever == toxic Mark Rutland <mark.rutland@arm.com> - 2016-09-16 16:50 +0200
        Re: [tip regression]  efi: Allow drivers to reserve boot services  forever == toxic Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-09-16 20:30 +0200
          Re: [tip regression]  efi: Allow drivers to reserve boot services  forever == toxic Mark Rutland <mark.rutland@arm.com> - 2016-09-19 11:00 +0200
      Re: [tip regression]  efi: Allow drivers to reserve boot services  forever == toxic Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-09-16 18:40 +0200
        Re: [tip regression]  efi: Allow drivers to reserve boot services  forever == toxic Matt Fleming <matt@codeblueprint.co.uk> - 2016-09-17 22:00 +0200
          Re: [tip regression]  efi: Allow drivers to reserve boot services  forever == toxic Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-09-18 08:10 +0200
            Re: [tip regression]  efi: Allow drivers to reserve boot services  forever == toxic Matt Fleming <matt@codeblueprint.co.uk> - 2016-09-19 13:20 +0200

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