Jordan, I think we could ASSERT() if the actually processors number is larger than maximum number supported in system.
Otherwise, send broadcast SMI or IPI may break the system. Jeff -----Original Message----- From: edk2-devel [mailto:[email protected]] On Behalf Of Jordan Justen Sent: Thursday, October 29, 2015 9:33 AM To: [email protected] Cc: Justen, Jordan L; Laszlo Ersek; Fan, Jeff Subject: [edk2] [PATCH 2/6] UefiCpuPkg/CpuDxe: Ignore extra APs in the system The PcdCpuMaxLogicalProcessorNumber specifies the maximum number of logical processors which are expected to be seen by the system. If more APs actually are available in the system, we should prevent them from being used. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jordan Justen <[email protected]> Cc: Jeff Fan <[email protected]> Cc: Laszlo Ersek <[email protected]> --- UefiCpuPkg/CpuDxe/CpuMp.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/UefiCpuPkg/CpuDxe/CpuMp.c b/UefiCpuPkg/CpuDxe/CpuMp.c index 98fdfdf..e80835f 100644 --- a/UefiCpuPkg/CpuDxe/CpuMp.c +++ b/UefiCpuPkg/CpuDxe/CpuMp.c @@ -1196,6 +1196,17 @@ WhoAmI ( } } + if (Index >= mMpSystemData.NumberOfProcessors) { + // + // This is not a valid error for the WhoAmI function, but it should never + // happen from outside the driver. It could only happen if more APs + // started than the PcdCpuMaxLogicalProcessorNumber was set to. This call + // would come from ApEntryPointInC, and we use this error to prevent the + // AP from being used by MP services. + // + return EFI_DEVICE_ERROR; + } + *ProcessorNumber = Index; return EFI_SUCCESS; } @@ -1446,10 +1457,15 @@ ApEntryPointInC ( VOID ) { + EFI_STATUS Status; VOID* TopOfApStack; UINTN ProcessorNumber; if (!mAPsAlreadyInitFinished) { + if (mMpSystemData.NumberOfProcessors >= gMaxLogicalProcessorNumber) { + return; + } + FillInProcessorInformation (FALSE, mMpSystemData.NumberOfProcessors); TopOfApStack = (UINT8*)mApStackStart + gApStackSize; mApStackStart = TopOfApStack; @@ -1461,7 +1477,11 @@ ApEntryPointInC ( mMpSystemData.NumberOfProcessors++; mMpSystemData.NumberOfEnabledProcessors++; } else { - WhoAmI (&mMpServicesTemplate, &ProcessorNumber); + Status = WhoAmI (&mMpServicesTemplate, &ProcessorNumber); + if (EFI_ERROR (Status)) { + return; + } + // // Get the original stack address. // -- 2.5.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
