ARRAY_SIZE(Mtrrs->Variables.Mtrr) was used in MtrrDebugPrintAllMtrrsWorker() to parse the MTRR registers. Instead, the actual variable MTRR count should be used. Otherwise, the uninitialized random data in MtrrSetting may cause MtrrLibSetMemoryType() hang.
Steven Shi found this bug in QEMU when using Q35 chip. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ruiyu Ni <[email protected]> Cc: Steven Shi <[email protected]> Cc: Laszlo Ersek <[email protected]> --- UefiCpuPkg/Library/MtrrLib/MtrrLib.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c index 2fd1d0153e..cb22558103 100644 --- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c +++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c @@ -2776,6 +2776,7 @@ MtrrDebugPrintAllMtrrsWorker ( UINTN RangeCount; UINT64 MtrrValidBitsMask; UINT64 MtrrValidAddressMask; + UINT32 VariableMtrrCount; MTRR_MEMORY_RANGE Ranges[ ARRAY_SIZE (mMtrrLibFixedMtrrTable) * sizeof (UINT64) + 2 * ARRAY_SIZE (Mtrrs->Variables.Mtrr) + 1 ]; @@ -2785,6 +2786,8 @@ MtrrDebugPrintAllMtrrsWorker ( return; } + VariableMtrrCount = GetVariableMtrrCountWorker (); + if (MtrrSetting != NULL) { Mtrrs = MtrrSetting; } else { @@ -2802,7 +2805,7 @@ MtrrDebugPrintAllMtrrsWorker ( DEBUG((DEBUG_CACHE, "Fixed MTRR[%02d] : %016lx\n", Index, Mtrrs->Fixed.Mtrr[Index])); } - for (Index = 0; Index < ARRAY_SIZE (Mtrrs->Variables.Mtrr); Index++) { + for (Index = 0; Index < VariableMtrrCount; Index++) { if (((MSR_IA32_MTRR_PHYSMASK_REGISTER *)&Mtrrs->Variables.Mtrr[Index].Mask)->Bits.V == 0) { // // If mask is not valid, then do not display range @@ -2829,11 +2832,11 @@ MtrrDebugPrintAllMtrrsWorker ( RangeCount = 1; MtrrLibGetRawVariableRanges ( - &Mtrrs->Variables, ARRAY_SIZE (Mtrrs->Variables.Mtrr), + &Mtrrs->Variables, VariableMtrrCount, MtrrValidBitsMask, MtrrValidAddressMask, RawVariableRanges ); MtrrLibApplyVariableMtrrs ( - RawVariableRanges, ARRAY_SIZE (RawVariableRanges), + RawVariableRanges, VariableMtrrCount, Ranges, ARRAY_SIZE (Ranges), &RangeCount ); -- 2.12.2.windows.2 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
