Thanks Steven.
All,
I will check in this patch ASAP.
Because it's just a bug fix in a corner of implementation and it may cause all
system hang.
-----Original Message-----
From: Shi, Steven
Sent: Tuesday, October 17, 2017 10:04 AM
To: Ni, Ruiyu <ruiyu...@intel.com>; edk2-devel@lists.01.org
Cc: Laszlo Ersek <ler...@redhat.com>
Subject: RE: [PATCH] UefiCpuPkg/MtrrLib: Fix MtrrDebugPrintAllMtrrsWorker to
avoid hang
Reviewed-by: Steven Shi <steven....@intel.com>
Steven Shi
Intel\SSG\STO\UEFI Firmware
Tel: +86 021-61166522
iNet: 821-6522
> -----Original Message-----
> From: Ni, Ruiyu
> Sent: Tuesday, October 17, 2017 9:47 AM
> To: edk2-devel@lists.01.org
> Cc: Shi, Steven <steven....@intel.com>; Laszlo Ersek
> <ler...@redhat.com>
> Subject: [PATCH] UefiCpuPkg/MtrrLib: Fix MtrrDebugPrintAllMtrrsWorker
> to avoid hang
>
> 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 <ruiyu...@intel.com>
> Cc: Steven Shi <steven....@intel.com>
> Cc: Laszlo Ersek <ler...@redhat.com>
> ---
> 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
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