[PATCH] UefiCpuPkg/PiSmmCpuDxeSmm: Refine casting result to bigger size

[PATCH] UefiCpuPkg/PiSmmCpuDxeSmm: Refine casting result to bigger size

[Hao Wu]

The commit is a follow-up of commit 8491e30.

In file MpService.c line 786:
Pte[Index] = (UINT64)((UINTN)PageTable + EFI_PAGE_SIZE * (Index + 1)) |
mAddressEncMask ...

(Where PageTable is of type VOID*, Index is of type UINTN, mAddressEncMask
is of type UINT64 and Pte[Index] is of type UINT64.)

Since in this case, the code logic ensures that the expression will not
exceed the range of UINTN, the commit will remove the explicit type cast
'(UINT64)'.

Cc: Jeff Fan <jeff.fan@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
---
 UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
index d99ad467b7..a1d16b4570 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
@@ -1,7 +1,7 @@
 /** @file
 SMM MP service implementation
 
-Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR>
 Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
 
 This program and the accompanying materials
@@ -783,7 +783,7 @@ Gen4GPageTable (
   // Set Page Directory Pointers
   //
   for (Index = 0; Index < 4; Index++) {
-    Pte[Index] = (UINT64)((UINTN)PageTable + EFI_PAGE_SIZE * (Index + 1)) | mAddressEncMask |
+    Pte[Index] = ((UINTN)PageTable + EFI_PAGE_SIZE * (Index + 1)) | mAddressEncMask |
                    (Is32BitPageTable ? IA32_PAE_PDPTE_ATTRIBUTE_BITS : PAGE_ATTRIBUTE_BITS);
   }
   Pte += EFI_PAGE_SIZE / sizeof (*Pte);
-- 
2.12.0.windows.1

Re: [PATCH] UefiCpuPkg/PiSmmCpuDxeSmm: Refine casting result to bigger size

[Fan, Jeff]

Reviewed-by: Jeff Fan <jeff.fan@intel.com>

-----Original Message-----
From: Wu, Hao A 
Sent: Tuesday, March 07, 2017 9:19 AM
To: edk2-devel@lists.01.org
Cc: Wu, Hao A; Fan, Jeff
Subject: [PATCH] UefiCpuPkg/PiSmmCpuDxeSmm: Refine casting result to bigger size

The commit is a follow-up of commit 8491e30.

In file MpService.c line 786:
Pte[Index] = (UINT64)((UINTN)PageTable + EFI_PAGE_SIZE * (Index + 1)) | mAddressEncMask ...

(Where PageTable is of type VOID*, Index is of type UINTN, mAddressEncMask is of type UINT64 and Pte[Index] is of type UINT64.)

Since in this case, the code logic ensures that the expression will not exceed the range of UINTN, the commit will remove the explicit type cast '(UINT64)'.

Cc: Jeff Fan <jeff.fan@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
---
 UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
index d99ad467b7..a1d16b4570 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
@@ -1,7 +1,7 @@
 /** @file
 SMM MP service implementation
 
-Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR>
 Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
 
 This program and the accompanying materials @@ -783,7 +783,7 @@ Gen4GPageTable (
   // Set Page Directory Pointers
   //
   for (Index = 0; Index < 4; Index++) {
-    Pte[Index] = (UINT64)((UINTN)PageTable + EFI_PAGE_SIZE * (Index + 1)) | mAddressEncMask |
+    Pte[Index] = ((UINTN)PageTable + EFI_PAGE_SIZE * (Index + 1)) | 
+ mAddressEncMask |
                    (Is32BitPageTable ? IA32_PAE_PDPTE_ATTRIBUTE_BITS : PAGE_ATTRIBUTE_BITS);
   }
   Pte += EFI_PAGE_SIZE / sizeof (*Pte);
--
2.12.0.windows.1