On 11/29/16 08:51, Jeff Fan wrote: > Some semaphores are not cleared on S3 boot path. For example, > mSmmMpSyncData->CpuData[CpuIndex].Present. It may still keeps the value set at > SMM runtime during S3 resume. It may causes BSP have the wrong judgement on > SMM > AP's present state. > > We have one related fix at e78a2a49ee6b0c0d7c6997c87ace31d7761cf636. But that > is > not completed. > > This fix is to clear Busy/Run/Present semaphores in InitializeMpSyncData(). > > Cc: Laszlo Ersek <ler...@redhat.com> > Cc: Feng Tian <feng.t...@intel.com> > Cc: Jiewen Yao <jiewen....@intel.com> > Cc: Michael D Kinney <michael.d.kin...@intel.com> > Contributed-under: TianoCore Contribution Agreement 1.0 > Signed-off-by: Jeff Fan <jeff....@intel.com> > --- > UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c > b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c > index cfbf59e..a873b68 100644 > --- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c > +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c > @@ -1357,6 +1357,9 @@ InitializeMpSyncData ( > (UINT32 *)((UINTN)mSmmCpuSemaphores.SemaphoreCpu.Run + > mSemaphoreSize * CpuIndex); > mSmmMpSyncData->CpuData[CpuIndex].Present = > (BOOLEAN *)((UINTN)mSmmCpuSemaphores.SemaphoreCpu.Present + > mSemaphoreSize * CpuIndex); > + *(mSmmMpSyncData->CpuData[CpuIndex].Busy) = 0; > + *(mSmmMpSyncData->CpuData[CpuIndex].Run) = 0; > + *(mSmmMpSyncData->CpuData[CpuIndex].Present) = FALSE; > } > } > } >
Even after this patch, the values pointed-to by the following fields of SemaphoreGlobal are not cleared: PFLock, CodeAccessCheckLock, MemoryMappedLock. Is that okay? The values pointed-to by the following fields of SemaphoreMsr are not cleared either: Msr, AvailableCounter. Is that okay? Can we imitate e78a2a49ee6b0c0d7c6997c87ace31d7761cf636 here; namely, can we save "SemaphoreBlock" and "TotalSize" from InitializeSmmCpuSemaphores() in global variables (in SMRAM), and then just do another ZeroMem() here? That would cover the currently listed objects (*Counter, *InsideSmm, *AllCpusInSync), and everything else too, in a future-proof way. In fact, I wonder if the ZeroMem() could be moved into InitializeMpSyncData() from InitializeSmmCpuSemaphores(). Of course, if some pointed-to objects must not be cleared, then the ZeroMem() is not appropriate. Thanks! Laszlo _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
