[PATCH v4 2/2] MdeMoudlePkg/CapsulePei: Substantial change on UefiCapsule.c

["Gao, Zhichao" <zhichao.gao@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1853

AreCapsulesStaged do not need to return the status, only boolean
result is useful. So directly return a boolean value.
Cannot initialize the variable at its definition.

GetScatterGatherHeadEntries: use allocated buffer instead of fixed
array to handle the condition which the SG list is larger then the
array size.

Remove API specifier AreCapsulesStaged and GetScatterGatherHeadEntries
because they are internal used.

Fix some coding style issues.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Cc: Michael Turner <Michael.Turner@microsoft.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Zhichao gao <zhichao.gao@intel.com>
---
 .../Universal/CapsulePei/UefiCapsule.c        | 103 +++++++++---------
 1 file changed, 54 insertions(+), 49 deletions(-)

diff --git a/MdeModulePkg/Universal/CapsulePei/UefiCapsule.c b/MdeModulePkg/Universal/CapsulePei/UefiCapsule.c
index 7c8c7a0f45..fabf30926c 100644
--- a/MdeModulePkg/Universal/CapsulePei/UefiCapsule.c
+++ b/MdeModulePkg/Universal/CapsulePei/UefiCapsule.c
@@ -1,7 +1,7 @@
 /** @file
   Capsule update PEIM for UEFI2.0
 
-Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
 Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
 
 SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -10,6 +10,8 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 
 #include "Capsule.h"
 
+#define DEFAULT_SG_LIST_HEADS       (20)
+
 #ifdef MDE_CPU_IA32
 //
 // Global Descriptor Table (GDT)
@@ -793,30 +795,21 @@ BuildMemoryResourceDescriptor (
 /**
   Check if the capsules are staged.
 
-  @param UpdateCapsules   A pointer to return the check result.
-
-  @retval EFI_INVALID_PARAMETER   The parameter is null.
-  @retval EFI_SUCCESS             The Capsules are staged.
+  @retval TRUE              The capsules are staged.
+  @retval FALSE             The capsules are not staged.
 
 **/
-EFI_STATUS
-EFIAPI
-AreCapsulesStaged(
-  OUT BOOLEAN     *UpdateCapsules
+BOOLEAN
+AreCapsulesStaged (
+  VOID
   )
 {
   EFI_STATUS                        Status;
   UINTN                             Size;
   EFI_PEI_READ_ONLY_VARIABLE2_PPI   *PPIVariableServices;
-  EFI_PHYSICAL_ADDRESS              CapsuleDataPtr64 = 0;
-
-  if (UpdateCapsules == NULL) {
-    DEBUG ((DEBUG_ERROR, "%a Invalid parameters.  Inputs can't be NULL\n", __FUNCTION__));
-    ASSERT (UpdateCapsules != NULL);
-    return EFI_INVALID_PARAMETER;
-  }
+  EFI_PHYSICAL_ADDRESS              CapsuleDataPtr64;
 
-  *UpdateCapsules = FALSE;
+  CapsuleDataPtr64 = 0;
 
   Status = PeiServicesLocatePpi(
               &gEfiPeiReadOnlyVariable2PpiGuid,
@@ -827,7 +820,7 @@ AreCapsulesStaged(
 
   if (EFI_ERROR (Status)) {
     DEBUG ((DEBUG_ERROR, "Failed to find ReadOnlyVariable2PPI\n"));
-    return Status;
+    return FALSE;
   }
 
   //
@@ -844,14 +837,12 @@ AreCapsulesStaged(
                                   );
 
   if (!EFI_ERROR (Status)) {
-    *UpdateCapsules = TRUE;
+    return TRUE;
   }
 
-  return EFI_SUCCESS;
+  return FALSE;
 }
 
-#define MAX_SG_LIST_HEADS (20)
-
 /**
   Check all the variables for SG list heads and get the count and addresses.
 
@@ -865,23 +856,24 @@ AreCapsulesStaged(
 
 **/
 EFI_STATUS
-EFIAPI
-GetScatterGatherHeadEntries(
+GetScatterGatherHeadEntries (
   OUT UINTN *ListLength,
   OUT EFI_PHYSICAL_ADDRESS **HeadList
   )
 {
-  EFI_STATUS                       Status;
-  UINTN                            Size;
-  UINTN                            Index;
-  UINTN                            TempIndex;
-  UINTN                            ValidIndex;
-  BOOLEAN                          Flag;
-  CHAR16                           CapsuleVarName[30];
-  CHAR16                           *TempVarName;
-  EFI_PHYSICAL_ADDRESS             CapsuleDataPtr64;
-  EFI_PEI_READ_ONLY_VARIABLE2_PPI  *PPIVariableServices;
-  EFI_PHYSICAL_ADDRESS             TempList[MAX_SG_LIST_HEADS];
+  EFI_STATUS                        Status;
+  UINTN                             Size;
+  UINTN                             Index;
+  UINTN                             TempIndex;
+  UINTN                             ValidIndex;
+  BOOLEAN                           Flag;
+  CHAR16                            CapsuleVarName[30];
+  CHAR16                            *TempVarName;
+  EFI_PHYSICAL_ADDRESS              CapsuleDataPtr64;
+  EFI_PEI_READ_ONLY_VARIABLE2_PPI   *PPIVariableServices;
+  EFI_PHYSICAL_ADDRESS              *TempList;
+  EFI_PHYSICAL_ADDRESS              *EnlargedTempList;
+  UINTN                             TempListLength;
 
   Index             = 0;
   TempVarName       = NULL;
@@ -911,16 +903,26 @@ GetScatterGatherHeadEntries(
     return Status;
   }
 
+  //
+  // Allocate memory for sg list head
+  //
+  TempListLength = DEFAULT_SG_LIST_HEADS * sizeof (EFI_PHYSICAL_ADDRESS);
+  TempList = AllocateZeroPool (TempListLength);
+  if (TempList == NULL) {
+    DEBUG((DEBUG_ERROR, "Failed to allocate memory\n"));
+    return EFI_OUT_OF_RESOURCES;
+  }
+
   //
   // setup var name buffer for update capsules
   //
   StrCpyS (CapsuleVarName, sizeof (CapsuleVarName) / sizeof (CHAR16), EFI_CAPSULE_VARIABLE_NAME);
   TempVarName = CapsuleVarName + StrLen (CapsuleVarName);
-  while (ValidIndex < MAX_SG_LIST_HEADS) {
+  while (TRUE) {
     if (Index != 0) {
       UnicodeValueToStringS (
         TempVarName,
-        (sizeof (CapsuleVarName) - ((StrLen (CapsuleVarName) + 1) * sizeof (CHAR16))),
+        (sizeof(CapsuleVarName) - ((UINTN)TempVarName - (UINTN)CapsuleVarName)),
         0,
         Index,
         0
@@ -958,6 +960,17 @@ GetScatterGatherHeadEntries(
       continue;
     }
 
+    //
+    // The TempList is full, enlarge it
+    //
+    if ((ValidIndex + 1) >= TempListLength) {
+      EnlargedTempList = AllocateZeroPool (TempListLength * 2);
+      CopyMem (EnlargedTempList, TempList, TempListLength);
+      FreePool (TempList);
+      TempList = EnlargedTempList;
+      TempListLength *= 2;
+    }
+
     //
     // add it to the cached list
     //
@@ -1122,19 +1135,11 @@ CheckCapsuleUpdate (
   IN EFI_PEI_SERVICES           **PeiServices
   )
 {
-  EFI_STATUS  Status;
-  BOOLEAN     Update;
-
-  Status = AreCapsulesStaged (&Update);
-
-  if (!EFI_ERROR (Status)) {
-    if (Update) {
-      Status = EFI_SUCCESS;
-    } else {
-      Status = EFI_NOT_FOUND;
-    }
+  if (AreCapsulesStaged ()) {
+    return EFI_SUCCESS;
+  } else {
+    return EFI_NOT_FOUND;
   }
-  return Status;
 }
 /**
   This function will look at a capsule and determine if it's a test pattern.
-- 
2.21.0.windows.1