tyler.durden/audk
1
0
Fork 0
mirror of https://github.com/acidanthera/audk.git synced 2025-04-08 17:05:09 +02:00
Code Issues Packages Projects Releases Wiki Activity

UefiCpuPkg/PiSmmCpuDxeSmm: Remove assert check for PDE entry not exist

Browse Source 
If 2MB-page is selected, PDE entry might exist, it's incorrect to assert
it's not exist. Detailed see blow case analysis (it's similar case if
address exceeds 4G):

Assume the Default Page table has covered below 6M size range:
[0000000000001000, 0000000000601000)
Then, with PageTableMap API, below Page table entry will be
created if 1G-page or 2M-page mode is selected:
[0000000000001000, 0000000000002000) -->  4K
[0000000000002000, 0000000000003000) -->  4K
...
[00000000001FF000, 0000000000200000) -->  4k
[0000000000200000, 0000000000400000) -->  2M
[0000000000400000, 0000000000600000) -->  2M
[0000000000600000, 0000000000601000) -->  4K
Above will cover 2M aligned address (0000000000600000) in page table. If
Page Fault happen by accessing 0000000000602000, need create the page
entry:
[0000000000602000, 0000000000603000) -->  4K
But PDE entry has been created/existed in page table with 0 PS bit.

So, this patch removes the assert check. The page table entry created
will be the platform-specified PageSize granularity.

Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
This commit is contained in:
Jiaxin Wu 2024-07-15 11:56:43 +08:00 committed by mergify[bot]
parent f73b97fe7f
commit 24f8b97a9d
1 changed files with 0 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
View File

@ -823,15 +823,6 @@ SmiDefaultPFHandler (
}
PTIndex = BitFieldRead64 (PFAddress, StartBit, StartBit + 8);
if ((PageTable[PTIndex] & IA32_PG_P) != 0) {
//
// Check if the entry has already existed, this issue may occur when the different
// size page entries created under the same entry
//
DEBUG ((DEBUG_ERROR, "PageTable = %lx, PTIndex = %x, PageTable[PTIndex] = %lx\n", PageTable, PTIndex, PageTable[PTIndex]));
DEBUG ((DEBUG_ERROR, "New page table overlapped with old page table!\n"));
ASSERT (FALSE);
}
//
// Fill the new entry