Revision: 18849
          http://sourceforge.net/p/edk2/code/18849
Author:   vanjeff
Date:     2015-11-17 05:13:43 +0000 (Tue, 17 Nov 2015)
Log Message:
-----------
UefiCpuPkg/PiSmmCpuDxeSmm: Shouldn't use gSmst->CurrentlyExecutingCpu

In ConfigSmmCodeAccessCheck(), we used gSmst->CurrentlyExecutingCpu to get the
current SMM BSP. But ConfigSmmCodeAccessCheck() maybe invoked before executing
SmmCoreEntry() and gSmst->CurrentlyExecutingCpu hasn't been updated to the
latest value. The code flow is as below:

  BSPHandler()
    gSmmCpuPrivate->SmmCoreEntryContext.CurrentlyExecutingCpu = CpuIndex;
    //
    // when mRestoreSmmConfigurationInS3 is set:
    //
    ConfigSmmCodeAccessCheck()
      //
      // reads gSmst->CurrentlyExecutingCpu to early
      //
    gSmmCpuPrivate->SmmCoreEntry (&gSmmCpuPrivate->SmmCoreEntryContext)
      //
      // sets gSmst->CurrentlyExecutingCpu with CopyMem() too late
      //
      CopyMem (&gSmmCoreSmst.SmmStartupThisAp,
        SmmEntryContext, sizeof (EFI_SMM_ENTRY_CONTEXT));

Instead, we should use
gSmmCpuPrivate->SmmCoreEntryContext.CurrentlyExecutingCpu directly.

(Sync patch r18715 from main trunk.)

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <[email protected]>
Reviewed-by: Laszlo Ersek <[email protected]>

Revision Links:
--------------
    http://sourceforge.net/p/edk2/code/18715

Modified Paths:
--------------
    branches/UDK2015/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c

Modified: branches/UDK2015/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
===================================================================
--- branches/UDK2015/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c 2015-11-17 
05:12:32 UTC (rev 18848)
+++ branches/UDK2015/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c 2015-11-17 
05:13:43 UTC (rev 18849)
@@ -1386,7 +1386,7 @@
   //
   // Check to see if the Feature Control MSR is supported on this CPU
   //
-  Index = gSmst->CurrentlyExecutingCpu;
+  Index = gSmmCpuPrivate->SmmCoreEntryContext.CurrentlyExecutingCpu;
   if (!SmmCpuFeaturesIsSmmRegisterSupported (Index, SmmRegFeatureControl)) {
     mSmmCodeAccessCheckEnable = FALSE;
     return;
@@ -1428,7 +1428,7 @@
   // Enable SMM Code Access Check feature for the APs.
   //
   for (Index = 0; Index < gSmst->NumberOfCpus; Index++) {
-    if (Index != gSmst->CurrentlyExecutingCpu) {
+    if (Index != gSmmCpuPrivate->SmmCoreEntryContext.CurrentlyExecutingCpu) {
 
       //
       // Acquire Config SMM Code Access Check spin lock.  The AP will release 
the


------------------------------------------------------------------------------
_______________________________________________
edk2-commits mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/edk2-commits

Reply via email to