[PATCH v1 3/9] CryptoPkg: Fix handling of &strcmp function pointers

[Qin Long <qin.long@intel.com>]

In a couple of places, OpenSSL code uses the address of the strcmp()
function, and assigns it to another comparator function pointer.

Unfortunately, this falls foul of the inconsistent function ABI that we
use in EDKII. We '#define strcmp AsciiStrCmp' but AsciiStrCmp is an
EFIAPI function with the Microsoft ABI. And we're assigning its address
to a non-EFIAPI function, which may well have a different ABI.

The compiler *should* have complained about this error, thus:

…/crypto/objects/o_names.c: In function ‘OBJ_NAME_new_index’:
…/crypto/objects/o_names.c:94:30: error: assignment from incompatible
 pointer type [-Werror=incompatible-pointer-types]
         name_funcs->cmp_func = OPENSSL_strcmp;
                              ^
There's another one in crypto/lhash/lhash.c::lh_new() which has an
explicit cast so even with compiler warnings we wouldn't have seen it.

Fix this by providing an actual strcmp() function in the default ABI.
We already *had* a prototype for it in OpenSslSupport.h, which was then
superseded by the #define strcmp AsciiStrCmp.

Now, OpenSSL code *can* use &strcmp without problems.

Cc: Ting Ye <ting.ye@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Gary Lin <glin@suse.com>
Cc: Ronald Cron <ronald.cron@arm.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Qin Long <qin.long@intel.com>
---
 CryptoPkg/Include/OpenSslSupport.h                | 3 +--
 CryptoPkg/Library/IntrinsicLib/MemoryIntrinsics.c | 8 +++++++-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/CryptoPkg/Include/OpenSslSupport.h b/CryptoPkg/Include/OpenSslSupport.h
index 91567c78f8..c3c5b5dcd7 100644
--- a/CryptoPkg/Include/OpenSslSupport.h
+++ b/CryptoPkg/Include/OpenSslSupport.h
@@ -1,7 +1,7 @@
 /** @file
   Root include file to support building OpenSSL Crypto Library.
 
-Copyright (c) 2010 - 2016, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2010 - 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
@@ -275,7 +275,6 @@ extern FILE  *stdout;
 #define memchr(buf,ch,count)              ScanMem8(buf,(UINTN)(count),(UINT8)ch)
 #define memcmp(buf1,buf2,count)           (int)(CompareMem(buf1,buf2,(UINTN)(count)))
 #define memmove(dest,source,count)        CopyMem(dest,source,(UINTN)(count))
-#define strcmp                            AsciiStrCmp
 #define strncmp(string1,string2,count)    (int)(AsciiStrnCmp(string1,string2,(UINTN)(count)))
 #define strcpy(strDest,strSource)         AsciiStrCpyS(strDest,MAX_STRING_SIZE,strSource)
 #define strncpy(strDest,strSource,count)  AsciiStrnCpyS(strDest,MAX_STRING_SIZE,strSource,(UINTN)count)
diff --git a/CryptoPkg/Library/IntrinsicLib/MemoryIntrinsics.c b/CryptoPkg/Library/IntrinsicLib/MemoryIntrinsics.c
index 9d6867ebce..e8a76d07ff 100644
--- a/CryptoPkg/Library/IntrinsicLib/MemoryIntrinsics.c
+++ b/CryptoPkg/Library/IntrinsicLib/MemoryIntrinsics.c
@@ -2,7 +2,7 @@
   Intrinsic Memory Routines Wrapper Implementation for OpenSSL-based
   Cryptographic Library.
 
-Copyright (c) 2010 - 2014, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2010 - 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
@@ -15,6 +15,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 
 #include <Base.h>
 #include <Library/BaseMemoryLib.h>
+#include <Library/BaseLib.h>
 
 /* OpenSSL will use floating point support, and C compiler produces the _fltused
    symbol by default. Simply define this symbol here to satisfy the linker. */
@@ -44,3 +45,8 @@ void * memset (void *dest, char ch, unsigned int count)
   
   return dest;
 }
+
+int strcmp (const char *s1, const char *s2)
+{
+  return (int)AsciiStrCmp(s1, s2);
+}
-- 
2.11.1.windows.1