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MdeModulePkg/Core: fix too many available pages between BS_Data 

The root cause is an unnecessary check to Size parameter in function
AdjustMemoryS(). It will cause one standalone free page (happen to have
Guard page around) in the free memory list cannot be allocated, even if
the requested memory size is less than a page.

  //
  // At least one more page needed for Guard page.
  //
  if (Size < (SizeRequested + EFI_PAGES_TO_SIZE (1))) {
    return 0;
  }

The following code in the same function actually covers above check
implicitly. So the fix is simply removing above check.

Cc: Star Zeng <star.zeng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
This commit is contained in:
Jian J Wang 2018-03-07 11:26:32 +08:00 committed by Star Zeng
parent 3d1872b780
commit 8b13bca9b8
2 changed files with 2 additions and 16 deletions
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9
MdeModulePkg/Core/Dxe/Mem/HeapGuard.c
View File

@ -1,7 +1,7 @@
/** @file
UEFI Heap Guard functions.
Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2017-2018, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
@ -905,13 +905,6 @@ AdjustMemoryS (
Target = Start + Size - SizeRequested;
//
// At least one more page needed for Guard page.
//
if (Size < (SizeRequested + EFI_PAGES_TO_SIZE (1))) {
return 0;
}
if (!IsGuardPage (Start + Size)) {
// No Guard at tail to share. One more page is needed.
Target -= EFI_PAGES_TO_SIZE (1);

9
MdeModulePkg/Core/PiSmmCore/HeapGuard.c
View File

@ -1,7 +1,7 @@
/** @file
UEFI Heap Guard functions.
Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2017-2018, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
@ -888,13 +888,6 @@ AdjustMemoryS (
Target = Start + Size - SizeRequested;
//
// At least one more page needed for Guard page.
//
if (Size < (SizeRequested + EFI_PAGES_TO_SIZE (1))) {
return 0;
}
if (!IsGuardPage (Start + Size)) {
// No Guard at tail to share. One more page is needed.
Target -= EFI_PAGES_TO_SIZE (1);