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vTPM: support little endian guests
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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>
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Hon Ching \(Vicky\) Lo authored and Peter Huewe committed Oct 18, 2015
1 parent 09e23a4 commit 0cc698a
Showing 2 changed files with 62 additions and 22 deletions.
78 changes: 56 additions & 22 deletions drivers/char/tpm/tpm_eventlog.c
View file
Original file line number Diff line number Diff line change
@@ -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;
@@ -107,20 +121,24 @@ 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)
return NULL;

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:
@@ -156,30 +174,33 @@ 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:
pc_event = (struct tcpa_pc_event *)event_entry;

/* ToDo Row data -> Base64 */

switch (pc_event->event_id) {
switch (do_endian_conversion(pc_event->event_id)) {
case SMBIOS:
case BIS_CERT:
case CMOS:
case NVRAM:
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);

6 changes: 6 additions & 0 deletions drivers/char/tpm/tpm_eventlog.h
View file
Original file line number Diff line number Diff line change
@@ -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,

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