Reviewed-by: Ray Ni <ray...@intel.com>
> -----Original Message-----
> From: Nikodem, Damian
> Sent: Wednesday, September 11, 2019 1:23 AM
> To: devel@edk2.groups.io
> Cc: Nikodem, Damian <damian.niko...@intel.com>; Dong, Eric
> <eric.d...@intel.com>; Ni, Ray <ray...@intel.com>; You,
> Benjamin <benjamin....@intel.com>; Laszlo Ersek <ler...@redhat.com>; Rusocki,
> Krzysztof <krzysztof.ruso...@intel.com>
> Subject: [PATCH v3] UefiCpuPkg: Fix potential spinLock issue in
> SmmStartupThisAp
>
> Due to needs a tackling the deficiency of the AP API, is necessary to ensure
> that in non-blocking mode
> previous AP executed command is finished before start new one.
>
> To remedy above:
> 1) execute AcquireSpinLock instead AcquireSpinLockOrFail - this will ensure
> time "window" to eliminate potential
> race condition beetwen BSP and AP spinLock release in non-blocking mode.
> This also will eliminate possibility to start executing new AP function
> before last is finished.
> 2) remove returns EFI_STATUS - EFI_NOT_READY - in new scenario returned
> status is not necessary to caller.
>
> Signed-off-by: Damian Nikodem <damian.niko...@intel.com>
> Cc: Eric Dong <eric.d...@intel.com>
> Cc: Ray Ni <ray...@intel.com>
> Cc: Benjamin You <benjamin....@intel.com>
> Cc: Laszlo Ersek <ler...@redhat.com>
> Cc: Krzysztof Rusocki <krzysztof.ruso...@intel.com>
>
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
> b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
> index d8d2b6f444..0685637c2b 100644
> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
> @@ -1235,14 +1235,9 @@ InternalSmmStartupThisAp (
> return EFI_INVALID_PARAMETER;
> }
>
> - if (Token == NULL) {
> - AcquireSpinLock (mSmmMpSyncData->CpuData[CpuIndex].Busy);
> - } else {
> - if (!AcquireSpinLockOrFail (mSmmMpSyncData->CpuData[CpuIndex].Busy)) {
> - DEBUG((DEBUG_ERROR, "Can't acquire
> mSmmMpSyncData->CpuData[%d].Busy\n", CpuIndex));
> - return EFI_NOT_READY;
> - }
> + AcquireSpinLock (mSmmMpSyncData->CpuData[CpuIndex].Busy);
>
> + if (Token != NULL) {
> *Token = (MM_COMPLETION) CreateToken ();
> }
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#47134): https://edk2.groups.io/g/devel/message/47134
Mute This Topic: https://groups.io/mt/34101181/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
