tpm-tools: replace memset with an implementation that can't be as easily

optimized away

Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>

Author: Kent Yoder

include/tpm_utils.h

@@ -65,6 +65,14 @@
 #define LOG_DEBUG               _("debug")
 #define LOG_LEVEL_DEBUG         3
 
+#ifdef __GNUC__
+#define __no_optimize __attribute__((optimize("O0")))
+#else
+#define __no_optimize
+#endif
+
+void * __no_optimize __memset(void *s, int c, size_t n);
+
 typedef int (*CmdOptParser)( const int aOpt, const char *aOptArg );
 typedef void (*CmdHelpFunction)( const char *aCmd );
 

lib/tpm_pkcs11.c

@@ -84,8 +84,8 @@ pkcsSlotInfo(CK_SLOT_INFO *a_ptSlotInfo ) {
 	char szSlotDesc[ sizeof( a_ptSlotInfo->slotDescription ) + 1 ];
 	char szSlotMfr[ sizeof( a_ptSlotInfo->manufacturerID ) + 1 ];
 
-	memset( szSlotDesc, 0, sizeof( szSlotDesc ) );
-	memset( szSlotMfr, 0, sizeof( szSlotMfr ) );
+	__memset( szSlotDesc, 0, sizeof( szSlotDesc ) );
+	__memset( szSlotMfr, 0, sizeof( szSlotMfr ) );
 
 	strncpy( szSlotDesc, (char *)a_ptSlotInfo->slotDescription,
 			sizeof( a_ptSlotInfo->slotDescription ) );
@@ -111,9 +111,9 @@ pkcsTokenInfo(CK_TOKEN_INFO *a_ptTokenInfo ) {
 	char szTokenMfr[ sizeof( a_ptTokenInfo->manufacturerID ) + 1 ];
 	char szTokenModel[ sizeof( a_ptTokenInfo->model ) + 1 ];
 
-	memset( szTokenLabel, 0, sizeof( szTokenLabel ) );
-	memset( szTokenMfr, 0, sizeof( szTokenMfr ) );
-	memset( szTokenModel, 0, sizeof( szTokenModel ) );
+	__memset( szTokenLabel, 0, sizeof( szTokenLabel ) );
+	__memset( szTokenMfr, 0, sizeof( szTokenMfr ) );
+	__memset( szTokenModel, 0, sizeof( szTokenModel ) );
 
 	strncpy( szTokenLabel, (char *)a_ptTokenInfo->label,
 			sizeof( a_ptTokenInfo->label ) );
@@ -172,7 +172,7 @@ openToken( char *a_pszTokenLabel ) {
 		goto out;
 
 	// Set the name of the TPM token
-	memset( szTokenLabel, ' ', sizeof( szTokenLabel ) );
+	__memset( szTokenLabel, ' ', sizeof( szTokenLabel ) );
 	if ( a_pszTokenLabel ) {
 		if ( strlen( a_pszTokenLabel ) > sizeof( szTokenLabel ) ) {
 			logError( _("The token label cannot be greater than %ld characters\n"), sizeof( szTokenLabel ) );

lib/tpm_unseal.c

@@ -465,7 +465,7 @@ int tpmUnsealFile( char* fname, unsigned char** tss_data, int* tss_size,
 void tpmUnsealShred(unsigned char* data, int size) {
 
 	if ( data != NULL ) {
-		memset( data, 0, size);
+		__memset( data, 0, size);
 		free(data);
 	}
 

lib/tpm_utils.c

@@ -69,7 +69,7 @@ genericOptHandler( int a_iNumArgs, char **a_pszArgs,
 	if ( a_pszShortOpts )
 		strcat( szShortOpts, a_pszShortOpts );
 
-	memset( sLongOpts, 0, sizeof( sLongOpts ) );
+	__memset( sLongOpts, 0, sizeof( sLongOpts ) );
 	memcpy( sLongOpts, sGenLongOpts, sizeof( sGenLongOpts ) );
 	if ( a_sLongOpts ) {
 		memcpy( sLongOpts + iNumGenLongOpts,
@@ -134,14 +134,20 @@ genericOptHandler( int a_iNumArgs, char **a_pszArgs,
 	return 0;
 }
 
+void * __no_optimize
+__memset(void *s, int c, size_t n)
+{
+	return memset(s, c, n);
+}
+
 /*
  * This function should be called when you are done with a password
  * the above getPasswd function to properly clean up.
  */
 void shredPasswd( char *a_pszPasswd ) {
 
 	if ( a_pszPasswd ) {
-		memset( a_pszPasswd, 0, strlen( a_pszPasswd ) );
+		__memset( a_pszPasswd, 0, strlen( a_pszPasswd ) );
 		free( a_pszPasswd );
 	}
 }
@@ -213,7 +219,7 @@ char *_getPasswd(const char *a_pszPrompt, int* a_iLen,
 
 	// pszPasswd is a static buffer, just clear it
 	if ( pszPasswd )
-		memset( pszPasswd, 0, strlen( pszPasswd ) );
+		__memset( pszPasswd, 0, strlen( pszPasswd ) );
 
 	return pszRetPasswd;
 }

src/tpm_mgmt/tpm_createek.c

@@ -93,7 +93,7 @@ static int readData(UINT32 bytesToRead, BYTE **buffer)
 	int rc = 0;
 	BYTE eofile;
 
-	memset(*buffer, 0x00, bytesToRead);
+	__memset(*buffer, 0x00, bytesToRead);
 	infile = fopen(in_filename, "r");
 	if ( !infile ){
 		logError(_("Unable to open input file: %s\n"),

src/tpm_mgmt/tpm_nvwrite.c

@@ -230,7 +230,7 @@ int main(int argc, char **argv)
 			logError(_("Out of memory.\n"));
 			return -1;
 		}
-		memset(rgbDataToWrite, fillvalue, ulDataLength);
+		__memset(rgbDataToWrite, fillvalue, ulDataLength);
 	} else {
 		ulDataLength = 0;
 	}