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| author | Jeff Brasen <jbrasen@nvidia.com> | 2022-09-23 09:56:16 -0600 |
|---|---|---|
| committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2022-09-23 17:58:00 +0000 |
| commit | ef9974b298583037a1686f08ee02798110a20ded (patch) | |
| tree | 69b952419ac7461b90e93ed62ff0ed93c365ba4a /EmbeddedPkg | |
| parent | 2500ce101178e55ed29cd18931ab8a73d0ca6e4d (diff) | |
| download | edk2-ef9974b298583037a1686f08ee02798110a20ded.tar.gz edk2-ef9974b298583037a1686f08ee02798110a20ded.tar.bz2 edk2-ef9974b298583037a1686f08ee02798110a20ded.zip | |
EmbeddedPkg/PrePi: Check for enough space before aligning heap pointer
Update check for enough space to occur prior to alignment offset.
This prevents cases where EfiFreeMemoryTop < EfiFreeMemoryBottom.
Signed-off-by: Jeff Brasen <jbrasen@nvidia.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Diffstat (limited to 'EmbeddedPkg')
| -rw-r--r-- | EmbeddedPkg/Library/PrePiMemoryAllocationLib/MemoryAllocationLib.c | 48 |
1 files changed, 21 insertions, 27 deletions
diff --git a/EmbeddedPkg/Library/PrePiMemoryAllocationLib/MemoryAllocationLib.c b/EmbeddedPkg/Library/PrePiMemoryAllocationLib/MemoryAllocationLib.c index 2cc2a71121..08a0add340 100644 --- a/EmbeddedPkg/Library/PrePiMemoryAllocationLib/MemoryAllocationLib.c +++ b/EmbeddedPkg/Library/PrePiMemoryAllocationLib/MemoryAllocationLib.c @@ -23,41 +23,35 @@ InternalAllocatePages ( )
{
EFI_PEI_HOB_POINTERS Hob;
- EFI_PHYSICAL_ADDRESS Offset;
+ EFI_PHYSICAL_ADDRESS NewTop;
Hob.Raw = GetHobList ();
- // Check to see if on 4k boundary
- Offset = Hob.HandoffInformationTable->EfiFreeMemoryTop & 0xFFF;
- if (Offset != 0) {
- // If not aligned, make the allocation aligned.
- Hob.HandoffInformationTable->EfiFreeMemoryTop -= Offset;
- }
+ NewTop = Hob.HandoffInformationTable->EfiFreeMemoryTop & ~(EFI_PHYSICAL_ADDRESS)EFI_PAGE_MASK;
+ NewTop -= Pages * EFI_PAGE_SIZE;
//
// Verify that there is sufficient memory to satisfy the allocation
//
- if (Hob.HandoffInformationTable->EfiFreeMemoryTop - ((Pages * EFI_PAGE_SIZE) + sizeof (EFI_HOB_MEMORY_ALLOCATION)) < Hob.HandoffInformationTable->EfiFreeMemoryBottom) {
- return 0;
- } else {
- //
- // Update the PHIT to reflect the memory usage
- //
- Hob.HandoffInformationTable->EfiFreeMemoryTop -= Pages * EFI_PAGE_SIZE;
-
- // This routine used to create a memory allocation HOB a la PEI, but that's not
- // necessary for us.
-
- //
- // Create a memory allocation HOB.
- //
- BuildMemoryAllocationHob (
- Hob.HandoffInformationTable->EfiFreeMemoryTop,
- Pages * EFI_PAGE_SIZE,
- MemoryType
- );
- return (VOID *)(UINTN)Hob.HandoffInformationTable->EfiFreeMemoryTop;
+ if (NewTop < (Hob.HandoffInformationTable->EfiFreeMemoryBottom + sizeof (EFI_HOB_MEMORY_ALLOCATION))) {
+ return NULL;
}
+
+ //
+ // Update the PHIT to reflect the memory usage
+ //
+ Hob.HandoffInformationTable->EfiFreeMemoryTop = NewTop;
+
+ //
+ // Create a memory allocation HOB.
+ //
+ BuildMemoryAllocationHob (
+ Hob.HandoffInformationTable->EfiFreeMemoryTop,
+ Pages * EFI_PAGE_SIZE,
+ MemoryType
+ );
+
+ return (VOID *)(UINTN)Hob.HandoffInformationTable->EfiFreeMemoryTop;
}
/**
|