> -----Original Message-----
> From: Wu, Hao A
> Sent: Friday, January 17, 2020 7:35 PM
> To: devel@edk2.groups.io
> Cc: Wu, Hao A; Dong, Eric; Ni, Ray; Laszlo Ersek; Kinney, Michael D
> Subject: [PATCH v2] UefiCpuPkg/MpInitLib: Fix possible uninitialized
> 'InitFlag' field
>
> REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2474
>
> Previous commit d786a17232:
> UefiCpuPkg/MpInitLib: Reduce the size when loading microcode patches
>
> Removed the below assignments for the 'InitFlag' field of CPU_MP_DATA
> structure in function MpInitLibInitialize() when APs are waken up to do
> some initialize sync:
>
> CpuMpData->InitFlag = ApInitReconfig;
> ...
> CpuMpData->InitFlag = ApInitDone;
>
> The above commit mistakenly assumed the 'InitFlag' field will have a value
> of 'ApInitDone' when the APs have been successfully waken up before. And
> since there is no explicit comparision for the 'InitFlag' field with the
> 'ApInitReconfig' value. The commit removed those assignments.
>
> However, under some cases (e.g. when variable OldCpuMpData is not NULL,
> which means function CollectProcessorCount() will not be called), removing
> the above assignments will left the 'InitFlag' field being uninitialized
> with a value of 0, which is a invalid value for the type of 'InitFlag'
> (AP_INIT_STATE).
>
> It may potentially cause the WakeUpAP() function to run some unnecessary
> codes when the APs have been successfully waken up before:
>
> if (CpuMpData->WakeUpByInitSipiSipi ||
> CpuMpData->InitFlag != ApInitDone) {
> ResetVectorRequired = TRUE;
> AllocateResetVector (CpuMpData);
> FillExchangeInfoData (CpuMpData);
> SaveLocalApicTimerSetting (CpuMpData);
> }
>
> This commit will address the above-mentioned issue.
>
> Test done:
> * OS boot on a real platform with multi processors
>
> Cc: Eric Dong <eric.d...@intel.com>
> Cc: Ray Ni <ray...@intel.com>
> Cc: Laszlo Ersek <ler...@redhat.com>
> Cc: Michael D Kinney <michael.d.kin...@intel.com>
> Signed-off-by: Hao A Wu <hao.a...@intel.com>
> Reviewed-by: Ray Ni <ray...@intel.com>
Since there are only comments and commit message changes compared with V1 patch,
I keep the R-b tag from Ray. Please help to raise if there is concern with this.
Best Regards,
Hao Wu
> ---
> UefiCpuPkg/Library/MpInitLib/MpLib.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c
> b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> index 6ec9b172b8..855d37ba3e 100644
> --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
> +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> @@ -1775,11 +1775,15 @@ MpInitLibInitialize (
> // Wakeup APs to do some AP initialize sync (Microcode & MTRR)
> //
> if (CpuMpData->CpuCount > 1) {
> + CpuMpData->InitFlag = ApInitReconfig;
> WakeUpAP (CpuMpData, TRUE, 0, ApInitializeSync, CpuMpData, TRUE);
> + //
> + // Wait for all APs finished initialization
> + //
> while (CpuMpData->FinishedCount < (CpuMpData->CpuCount - 1)) {
> CpuPause ();
> }
> -
> + CpuMpData->InitFlag = ApInitDone;
> for (Index = 0; Index < CpuMpData->CpuCount; Index++) {
> SetApState (&CpuMpData->CpuData[Index], CpuStateIdle);
> }
> --
> 2.12.0.windows.1
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