vboot TPM stub functions return error codes

TlclStubInit, TlclCloseDevice, and TlclOpenDevice were void functions but
should return error codes.

BUG=chromium-os:6695
TEST=RUNTESTS=1 make && emerge successfully

Review URL: http://codereview.chromium.org/5796005

Change-Id: I8ddbf8b1f080d98ff6ed42c4a675fbda5b17eef1

firmware/include/tlcl_stub.h

@@ -17,15 +17,15 @@
 /*****************************************************************************/
 /* Functions to be implemented by the stub library */
 
-/* Initialize the stub library */
-void TlclStubInit(void);
+/* Initialize the stub library.  Returns 0 if success, nonzero if error. */
+uint32_t TlclStubInit(void);
 
 /* Close and open the device.  This is needed for running more complex commands
  * at user level, such as TPM_TakeOwnership, since the TPM device can be opened
- * only by one process at a time.
+ * only by one process at a time.  Returns 0 if success, nonzero if error.
  */
-void TlclCloseDevice(void);
-void TlclOpenDevice(void);
+uint32_t TlclCloseDevice(void);
+uint32_t TlclOpenDevice(void);
 
 /* Send data to the TPM and receive a response.  Returns 0 if success,
  * nonzero if error. */

firmware/include/tss_constants.h

@@ -22,6 +22,7 @@
 #define TPM_E_AREA_LOCKED           ((uint32_t)0x0000003c)
 #define TPM_E_BADINDEX              ((uint32_t)0x00000002)
 #define TPM_E_BAD_PRESENCE          ((uint32_t)0x0000002d)
+#define TPM_E_IOERROR               ((uint32_t)0x0000001f)
 #define TPM_E_INVALID_POSTINIT      ((uint32_t)0x00000026)
 #define TPM_E_MAXNVWRITES           ((uint32_t)0x00000048)
 #define TPM_E_OWNER_SET             ((uint32_t)0x00000014)

firmware/lib/rollback_index.c

@@ -197,8 +197,7 @@ uint32_t SetupTPM(int recovery_mode, int developer_mode,
     g_rollback_recovery_mode = 1;  /* Global variables are usable in
                                     * recovery mode */
 
-  /* TODO: TlclLibInit() should be able to return failure */
-  TlclLibInit();
+  RETURN_ON_FAILURE(TlclLibInit());
 
   RETURN_ON_FAILURE(TlclStartup());
   /* Use ContinueSelfTest rather than SelfTestFull().  It enables
@@ -336,7 +335,7 @@ uint32_t RollbackKernelLock(void) {
 
 uint32_t RollbackS3Resume(void) {
   uint32_t result;
-  TlclLibInit();
+  RETURN_ON_FAILURE(TlclLibInit());
   result = TlclResume();
   if (result == TPM_E_INVALID_POSTINIT) {
     /* We're on a platform where the TPM maintains power in S3, so

firmware/lib/tpm_lite/include/tlcl.h

@@ -18,9 +18,9 @@
 /*****************************************************************************/
 /* Functions implemented in tlcl.c */
 
-/* Call this first.
+/* Call this first.  Returns 0 if success, nonzero if error.
  */
-void TlclLibInit(void);
+uint32_t TlclLibInit(void);
 
 /* Logs to stdout.  Arguments like printf.
  */

firmware/lib/tpm_lite/tlcl.c

@@ -91,8 +91,8 @@ static uint32_t Send(const uint8_t* command) {
 
 /* Exported functions. */
 
-void TlclLibInit(void) {
-  TlclStubInit();
+uint32_t TlclLibInit(void) {
+  return TlclStubInit();
 }
 
 uint32_t TlclStartup(void) {

firmware/stub/tpm_lite_stub.c

@@ -99,22 +99,25 @@ POSSIBLY_UNUSED static INLINE int TpmResponseSize(const uint8_t* buffer) {
 }
 
 
-void TlclStubInit(void) {
-  TlclOpenDevice();
+uint32_t TlclStubInit(void) {
+  return TlclOpenDevice();
 }
 
 
-void TlclCloseDevice(void) {
-  close(tpm_fd);
-  tpm_fd = -1;
+uint32_t TlclCloseDevice(void) {
+  if (tpm_fd != -1) {
+    close(tpm_fd);
+    tpm_fd = -1;
+  }
+  return 0;
 }
 
 
-void TlclOpenDevice(void) {
+uint32_t TlclOpenDevice(void) {
   char* device_path;
 
   if (tpm_fd >= 0)
-    return;  /* Already open */
+    return 0;  /* Already open */
 
   device_path = getenv("TPM_DEVICE_PATH");
   if (device_path == NULL) {
@@ -123,8 +126,12 @@ void TlclOpenDevice(void) {
 
   tpm_fd = open(device_path, O_RDWR);
   if (tpm_fd < 0) {
-    error("cannot open TPM device %s: %s\n", device_path, strerror(errno));
+    VBDEBUG(("TPM: Cannot open TPM device %s: %s\n", device_path,
+             strerror(errno)));
+    return TPM_E_IOERROR;
   }
+
+  return 0;
 }