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| author | Jian J Wang <devel@edk2.groups.io> | 2019-11-06 21:13:32 +0000 |
|---|---|---|
| committer | Jian J Wang <jian.j.wang@intel.com> | 2019-11-09 10:59:56 +0800 |
| commit | f9d0e5daa058f0cf4caa8edad0dfa2a3a390f1b0 (patch) | |
| tree | 62b0ec3b72a397648939a184dda1f4f143aae74c /MdeModulePkg | |
| parent | f55c76b301f15d287b58cd86dd59be978dc753a3 (diff) | |
| download | edk2-f9d0e5daa058f0cf4caa8edad0dfa2a3a390f1b0.tar.gz | |
MdeModulePkg/DxeIplPeim: reserve page 0 for NULL pointer detection
When a boot loader examines the memory map, it can see that location 0
is available memory. If it chooses to use that memory, and
PcdNullPointerDetectionPropertyMask is enabled, use of memory in page 0
will cause an exception. This does occur when running the memtest86
program.
Leaving page 0 available is for legacy support purpose. Since we have
deprecated the support of legacy, the solution is just reserving it so
that it cannot be allocated for other uses.
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1885
Cc: Dandan Bi <dandan.bi@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Diffstat (limited to 'MdeModulePkg')
| -rw-r--r-- | MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c | 4 | ||||
| -rw-r--r-- | MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c | 4 |
2 files changed, 8 insertions, 0 deletions
diff --git a/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c b/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c index 172d7cd1c6..6e8ca824d4 100644 --- a/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c +++ b/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c @@ -246,8 +246,12 @@ HandOffToDxeCore ( EFI_PEI_VECTOR_HANDOFF_INFO_PPI *VectorHandoffInfoPpi;
BOOLEAN BuildPageTablesIa32Pae;
+ //
+ // Clear page 0 and mark it as allocated if NULL pointer detection is enabled.
+ //
if (IsNullDetectionEnabled ()) {
ClearFirst4KPage (HobList.Raw);
+ BuildMemoryAllocationHob (0, EFI_PAGES_TO_SIZE (1), EfiBootServicesData);
}
Status = PeiServicesAllocatePages (EfiBootServicesData, EFI_SIZE_TO_PAGES (STACK_SIZE), &BaseOfStack);
diff --git a/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c b/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c index 2867610bff..f465eb1d8a 100644 --- a/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c +++ b/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c @@ -36,8 +36,12 @@ HandOffToDxeCore ( EFI_VECTOR_HANDOFF_INFO *VectorInfo;
EFI_PEI_VECTOR_HANDOFF_INFO_PPI *VectorHandoffInfoPpi;
+ //
+ // Clear page 0 and mark it as allocated if NULL pointer detection is enabled.
+ //
if (IsNullDetectionEnabled ()) {
ClearFirst4KPage (HobList.Raw);
+ BuildMemoryAllocationHob (0, EFI_PAGES_TO_SIZE (1), EfiBootServicesData);
}
//
|