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IntelFrameworkModulePkg: Refine type cast for pointer subtraction 

For pointer subtraction, the result is of type "ptrdiff_t". According to
the C11 standard (Committee Draft - April 12, 2011):

"When two pointers are subtracted, both shall point to elements of the
same array object, or one past the last element of the array object; the
result is the difference of the subscripts of the two array elements. The
size of the result is implementation-defined, and its type (a signed
integer type) is ptrdiff_t defined in the <stddef.h> header. If the result
is not representable in an object of that type, the behavior is
undefined."

In our codes, there are cases that the pointer subtraction is not
performed by pointers to elements of the same array object. This might
lead to potential issues, since the behavior is undefined according to C11
standard.

Also, since the size of type "ptrdiff_t" is implementation-defined. Some
static code checkers may warn that the pointer subtraction might underflow
first and then being cast to a bigger size. For example:

UINT8  *Ptr1, *Ptr2;
UINTN  PtrDiff;
...
PtrDiff = (UINTN) (Ptr1 - Ptr2);

The commit will refine the pointer subtraction expressions by casting each
pointer to UINTN first and then perform the subtraction:

PtrDiff = (UINTN) Ptr1 - (UINTN) Ptr2;

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
This commit is contained in:
Hao Wu 2017-01-23 09:53:45 +08:00
parent 6e4489d812
commit 4ff5fd203c
6 changed files with 13 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
View File

@ -1,6 +1,6 @@
/** @file
Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions
@ -318,7 +318,7 @@ GetPciLegacyRom (
break;
}
if ((UINTN)(RomHeader.Raw - (UINT8 *) *Rom) + Pcir->ImageLength * 512 > *ImageSize) {
if (((UINTN)RomHeader.Raw - (UINTN)*Rom) + Pcir->ImageLength * 512 > *ImageSize) {
break;
}

4
IntelFrameworkModulePkg/Library/GenericBdsLib/BdsBoot.c
View File

@ -1,7 +1,7 @@
/** @file
BDS Lib functions which relate with create or process the boot option.
Copyright (c) 2004 - 2016, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2004 - 2017, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
@ -1034,7 +1034,7 @@ BdsCreateDevOrder (
DevOrderPtr->Length = (UINT16) (sizeof (UINT16) + BEVCount * sizeof (UINT16));
DevOrderPtr = (LEGACY_DEV_ORDER_ENTRY *) BdsFillDevOrderBuf (BbsTable, BBS_BEV_DEVICE, BbsCount, DevOrderPtr->Data);
ASSERT (TotalSize == (UINTN) ((UINT8 *) DevOrderPtr - (UINT8 *) DevOrder));
ASSERT (TotalSize == ((UINTN) DevOrderPtr - (UINTN) DevOrder));
//
// Save device order for legacy boot device to variable.

4
IntelFrameworkModulePkg/Library/GenericBdsLib/BdsConsole.c
View File

@ -1,7 +1,7 @@
/** @file
BDS Lib functions which contain all the code to connect console device
Copyright (c) 2004 - 2014, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2004 - 2017, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
@ -873,7 +873,7 @@ ConvertBmpToGopBlt (
}
ImageIndex = (UINTN) (Image - ImageHeader);
ImageIndex = (UINTN)Image - (UINTN)ImageHeader;
if ((ImageIndex % 4) != 0) {
//
// Bmp Image starts each row on a 32-bit boundary!

4
IntelFrameworkModulePkg/Library/GenericBdsLib/BdsMisc.c
View File

@ -1,7 +1,7 @@
/** @file
Misc BDS library function
Copyright (c) 2004 - 2015, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2004 - 2017, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
@ -669,7 +669,7 @@ BdsLibVariableToOption (
// Get load opion data.
//
LoadOptions = TempPtr;
LoadOptionsSize = (UINT32) (VariableSize - (UINTN) (TempPtr - Variable));
LoadOptionsSize = (UINT32) (VariableSize - ((UINTN)TempPtr - (UINTN)Variable));
//
// The Console variables may have multiple device paths, so make

4
IntelFrameworkModulePkg/Library/LegacyBootManagerLib/LegacyBm.c
View File

@ -3,7 +3,7 @@
and manage the legacy boot option, all legacy boot option is getting from
the legacy BBS table.
Copyright (c) 2011 - 2016, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2011 - 2017, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
@ -725,7 +725,7 @@ LegacyBmCreateDevOrder (
DevOrderPtr->Length = (UINT16) (sizeof (UINT16) + BEVCount * sizeof (UINT16));
DevOrderPtr = (LEGACY_DEV_ORDER_ENTRY *) LegacyBmFillDevOrderBuf (BbsTable, BBS_BEV_DEVICE, BbsCount, DevOrderPtr->Data);
ASSERT (TotalSize == (UINTN) ((UINT8 *) DevOrderPtr - (UINT8 *) DevOrder));
ASSERT (TotalSize == ((UINTN) DevOrderPtr - (UINTN) DevOrder));
//
// Save device order for legacy boot device to variable.

6
IntelFrameworkModulePkg/Universal/BdsDxe/BootMaint/BootOption.c
View File

@ -5,7 +5,7 @@
Boot option manipulation
Copyright (c) 2004 - 2015, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2004 - 2017, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
@ -1124,7 +1124,7 @@ BOpt_AppendFileName (
// that overlap.
//
StrCpyS (TmpStr, MaxLen, Ptr + 3);
StrCpyS (LastSlash, MaxLen - (UINTN) (LastSlash - Str), TmpStr);
StrCpyS (LastSlash, MaxLen - ((UINTN) LastSlash - (UINTN) Str) / sizeof (CHAR16), TmpStr);
Ptr = LastSlash;
} else if (*Ptr == '\\' && *(Ptr + 1) == '.' && *(Ptr + 2) == '\\') {
//
@ -1136,7 +1136,7 @@ BOpt_AppendFileName (
// that overlap.
//
StrCpyS (TmpStr, MaxLen, Ptr + 2);
StrCpyS (Ptr, MaxLen - (UINTN) (Ptr - Str), TmpStr);
StrCpyS (Ptr, MaxLen - ((UINTN) Ptr - (UINTN) Str) / sizeof (CHAR16), TmpStr);
Ptr = LastSlash;
} else if (*Ptr == '\\') {
LastSlash = Ptr;