vTPM: support little endian guests

This patch makes the code endianness independent. We defined a
macro do_endian_conversion to apply endianness to raw integers
in the event entries so that they will be displayed properly.
tpm_binary_bios_measurements_show() is modified for the display.

Signed-off-by: Hon Ching(Vicky) Lo <honclo@linux.vnet.ibm.com>
Signed-off-by: Joy Latten <jmlatten@linux.vnet.ibm.com>
Reviewed-by: Ashley Lai <ashley@ahsleylai.com>
Reviewed-by: Ashley Lai <ashley@ahsleylai.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>

drivers/char/tpm/tpm_eventlog.c

@@ -76,15 +76,25 @@ static void *tpm_bios_measurements_start(struct seq_file *m, loff_t *pos)
 	void *addr = log->bios_event_log;
 	void *limit = log->bios_event_log_end;
 	struct tcpa_event *event;
+	u32 converted_event_size;
+	u32 converted_event_type;
+
 
 	/* read over *pos measurements */
 	for (i = 0; i < *pos; i++) {
 		event = addr;
 
+		converted_event_size =
+		    do_endian_conversion(event->event_size);
+		converted_event_type =
+		    do_endian_conversion(event->event_type);
+
 		if ((addr + sizeof(struct tcpa_event)) < limit) {
-			if (event->event_type == 0 && event->event_size == 0)
+			if ((converted_event_type == 0) &&
+			    (converted_event_size == 0))
 				return NULL;
-			addr += sizeof(struct tcpa_event) + event->event_size;
+			addr += (sizeof(struct tcpa_event) +
+				 converted_event_size);
 		}
 	}
 
@@ -94,8 +104,12 @@ static void *tpm_bios_measurements_start(struct seq_file *m, loff_t *pos)
 
 	event = addr;
 
-	if ((event->event_type == 0 && event->event_size == 0) ||
-	    ((addr + sizeof(struct tcpa_event) + event->event_size) >= limit))
+	converted_event_size = do_endian_conversion(event->event_size);
+	converted_event_type = do_endian_conversion(event->event_type);
+
+	if (((converted_event_type == 0) && (converted_event_size == 0))
+	    || ((addr + sizeof(struct tcpa_event) + converted_event_size)
+		>= limit))
 		return NULL;
 
 	return addr;
@@ -107,8 +121,12 @@ static void *tpm_bios_measurements_next(struct seq_file *m, void *v,
 	struct tcpa_event *event = v;
 	struct tpm_bios_log *log = m->private;
 	void *limit = log->bios_event_log_end;
+	u32 converted_event_size;
+	u32 converted_event_type;
 
-	v += sizeof(struct tcpa_event) + event->event_size;
+	converted_event_size = do_endian_conversion(event->event_size);
+
+	v += sizeof(struct tcpa_event) + converted_event_size;
 
 	/* now check if current entry is valid */
 	if ((v + sizeof(struct tcpa_event)) >= limit)
@@ -116,11 +134,11 @@ static void *tpm_bios_measurements_next(struct seq_file *m, void *v,
 
 	event = v;
 
-	if (event->event_type == 0 && event->event_size == 0)
-		return NULL;
+	converted_event_size = do_endian_conversion(event->event_size);
+	converted_event_type = do_endian_conversion(event->event_type);
 
-	if ((event->event_type == 0 && event->event_size == 0) ||
-	    ((v + sizeof(struct tcpa_event) + event->event_size) >= limit))
+	if (((converted_event_type == 0) && (converted_event_size == 0)) ||
+	    ((v + sizeof(struct tcpa_event) + converted_event_size) >= limit))
 		return NULL;
 
 	(*pos)++;
@@ -140,7 +158,7 @@ static int get_event_name(char *dest, struct tcpa_event *event,
 	int i, n_len = 0, d_len = 0;
 	struct tcpa_pc_event *pc_event;
 
-	switch(event->event_type) {
+	switch (do_endian_conversion(event->event_type)) {
 	case PREBOOT:
 	case POST_CODE:
 	case UNUSED:
@@ -156,14 +174,16 @@ static int get_event_name(char *dest, struct tcpa_event *event,
 	case NONHOST_CODE:
 	case NONHOST_CONFIG:
 	case NONHOST_INFO:
-		name = tcpa_event_type_strings[event->event_type];
+		name = tcpa_event_type_strings[do_endian_conversion
+						(event->event_type)];
 		n_len = strlen(name);
 		break;
 	case SEPARATOR:
 	case ACTION:
-		if (MAX_TEXT_EVENT > event->event_size) {
+		if (MAX_TEXT_EVENT >
+		    do_endian_conversion(event->event_size)) {
 			name = event_entry;
-			n_len = event->event_size;
+			n_len = do_endian_conversion(event->event_size);
 		}
 		break;
 	case EVENT_TAG:
@@ -171,7 +191,7 @@ static int get_event_name(char *dest, struct tcpa_event *event,
 
 		/* ToDo Row data -> Base64 */
 
-		switch (pc_event->event_id) {
+		switch (do_endian_conversion(pc_event->event_id)) {
 		case SMBIOS:
 		case BIS_CERT:
 		case CMOS:
@@ -179,7 +199,8 @@ static int get_event_name(char *dest, struct tcpa_event *event,
 		case OPTION_ROM_EXEC:
 		case OPTION_ROM_CONFIG:
 		case S_CRTM_VERSION:
-			name = tcpa_pc_event_id_strings[pc_event->event_id];
+			name = tcpa_pc_event_id_strings[do_endian_conversion
+							(pc_event->event_id)];
 			n_len = strlen(name);
 			break;
 		/* hash data */
@@ -188,7 +209,8 @@ static int get_event_name(char *dest, struct tcpa_event *event,
 		case OPTION_ROM_MICROCODE:
 		case S_CRTM_CONTENTS:
 		case POST_CONTENTS:
-			name = tcpa_pc_event_id_strings[pc_event->event_id];
+			name = tcpa_pc_event_id_strings[do_endian_conversion
+							(pc_event->event_id)];
 			n_len = strlen(name);
 			for (i = 0; i < 20; i++)
 				d_len += sprintf(&data[2*i], "%02x",
@@ -209,13 +231,24 @@ static int get_event_name(char *dest, struct tcpa_event *event,
 static int tpm_binary_bios_measurements_show(struct seq_file *m, void *v)
 {
 	struct tcpa_event *event = v;
-	char *data = v;
+	struct tcpa_event temp_event;
+	char *tempPtr;
 	int i;
 
-	for (i = 0; i < sizeof(struct tcpa_event) + event->event_size; i++)
-		seq_putc(m, data[i]);
+	memcpy(&temp_event, event, sizeof(struct tcpa_event));
+
+	/* convert raw integers for endianness */
+	temp_event.pcr_index = do_endian_conversion(event->pcr_index);
+	temp_event.event_type = do_endian_conversion(event->event_type);
+	temp_event.event_size = do_endian_conversion(event->event_size);
+
+	tempPtr = (char *)&temp_event;
+
+	for (i = 0; i < sizeof(struct tcpa_event) + temp_event.event_size; i++)
+		seq_putc(m, tempPtr[i]);
 
 	return 0;
+
 }
 
 static int tpm_bios_measurements_release(struct inode *inode,
@@ -238,7 +271,7 @@ static int tpm_ascii_bios_measurements_show(struct seq_file *m, void *v)
 	char *eventname;
 	struct tcpa_event *event = v;
 	unsigned char *event_entry =
-	    (unsigned char *) (v + sizeof(struct tcpa_event));
+	    (unsigned char *)(v + sizeof(struct tcpa_event));
 
 	eventname = kmalloc(MAX_TEXT_EVENT, GFP_KERNEL);
 	if (!eventname) {
@@ -247,13 +280,14 @@ static int tpm_ascii_bios_measurements_show(struct seq_file *m, void *v)
 		return -EFAULT;
 	}
 
-	seq_printf(m, "%2d ", event->pcr_index);
+	/* 1st: PCR */
+	seq_printf(m, "%2d ", do_endian_conversion(event->pcr_index));
 
 	/* 2nd: SHA1 */
 	seq_printf(m, "%20phN", event->pcr_value);
 
 	/* 3rd: event type identifier */
-	seq_printf(m, " %02x", event->event_type);
+	seq_printf(m, " %02x", do_endian_conversion(event->event_type));
 
 	len += get_event_name(eventname, event, event_entry);
 

drivers/char/tpm/tpm_eventlog.h

@@ -6,6 +6,12 @@
 #define MAX_TEXT_EVENT		1000	/* Max event string length */
 #define ACPI_TCPA_SIG		"TCPA"	/* 0x41504354 /'TCPA' */
 
+#ifdef CONFIG_PPC64
+#define do_endian_conversion(x) be32_to_cpu(x)
+#else
+#define do_endian_conversion(x) x
+#endif
+
 enum bios_platform_class {
 	BIOS_CLIENT = 0x00,
 	BIOS_SERVER = 0x01,