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Subject[PATCH 3/5] tpm: Use library version of calc_tpm2_event_size in sysfs code
Date
From: Bartosz Szczepanek <bsz@semihalf.com>

Expect negative values from calc_tpm2_event_size as error codes.
Pass efispecid instead of event header to calc_tpm2_event_size.

Also, include tpm library in the build.

Signed-off-by: Bartosz Szczepanek <bsz@semihalf.com>
---
drivers/char/tpm/eventlog/tpm2.c | 89 ++++++++--------------------------------
include/linux/tpm_eventlog.h | 3 ++
lib/Makefile | 2 +
3 files changed, 22 insertions(+), 72 deletions(-)

diff --git a/drivers/char/tpm/eventlog/tpm2.c b/drivers/char/tpm/eventlog/tpm2.c
index 1b8fa9de2cac..5230821d5b1c 100644
--- a/drivers/char/tpm/eventlog/tpm2.c
+++ b/drivers/char/tpm/eventlog/tpm2.c
@@ -26,80 +26,20 @@
#include "../tpm.h"
#include "common.h"

-/*
- * calc_tpm2_event_size() - calculate the event size, where event
- * is an entry in the TPM 2.0 event log. The event is of type Crypto
- * Agile Log Entry Format as defined in TCG EFI Protocol Specification
- * Family "2.0".
-
- * @event: event whose size is to be calculated.
- * @event_header: the first event in the event log.
- *
- * Returns size of the event. If it is an invalid event, returns 0.
- */
-static int calc_tpm2_event_size(struct tcg_pcr_event2 *event,
- struct tcg_pcr_event *event_header)
-{
- struct tcg_efi_specid_event *efispecid;
- struct tcg_event_field *event_field;
- void *marker;
- void *marker_start;
- u32 halg_size;
- size_t size;
- u16 halg;
- int i;
- int j;
-
- marker = event;
- marker_start = marker;
- marker = marker + sizeof(event->pcr_idx) + sizeof(event->event_type)
- + sizeof(event->count);
-
- efispecid = (struct tcg_efi_specid_event *)event_header->event;
-
- /* Check if event is malformed. */
- if (event->count > efispecid->num_algs)
- return 0;
-
- for (i = 0; i < event->count; i++) {
- halg_size = sizeof(event->digests[i].alg_id);
- memcpy(&halg, marker, halg_size);
- marker = marker + halg_size;
- for (j = 0; j < efispecid->num_algs; j++) {
- if (halg == efispecid->digest_sizes[j].alg_id) {
- marker +=
- efispecid->digest_sizes[j].digest_size;
- break;
- }
- }
- /* Algorithm without known length. Such event is unparseable. */
- if (j == efispecid->num_algs)
- return 0;
- }
-
- event_field = (struct tcg_event_field *)marker;
- marker = marker + sizeof(event_field->event_size)
- + event_field->event_size;
- size = marker - marker_start;
-
- if ((event->event_type == 0) && (event_field->event_size == 0))
- return 0;
-
- return size;
-}
-
static void *tpm2_bios_measurements_start(struct seq_file *m, loff_t *pos)
{
struct tpm_chip *chip = m->private;
struct tpm_bios_log *log = &chip->log;
void *addr = log->bios_event_log;
void *limit = log->bios_event_log_end;
+ struct tcg_efi_specid_event *efispecid;
struct tcg_pcr_event *event_header;
struct tcg_pcr_event2 *event;
- size_t size;
+ ssize_t size;
int i;

event_header = addr;
+ efispecid = (struct tcg_efi_specid_event *) event_header->event;
size = sizeof(struct tcg_pcr_event) - sizeof(event_header->event)
+ event_header->event_size;

@@ -115,16 +55,16 @@ static void *tpm2_bios_measurements_start(struct seq_file *m, loff_t *pos)
if (*pos > 0) {
addr += size;
event = addr;
- size = calc_tpm2_event_size(event, event_header);
- if ((addr + size >= limit) || (size == 0))
+ size = calc_tpm2_event_size(event, efispecid);
+ if ((addr + size >= limit) || (size < 0))
return NULL;
}

for (i = 0; i < (*pos - 1); i++) {
event = addr;
- size = calc_tpm2_event_size(event, event_header);
+ size = calc_tpm2_event_size(event, efispecid);

- if ((addr + size >= limit) || (size == 0))
+ if ((addr + size >= limit) || (size < 0))
return NULL;
addr += size;
}
@@ -135,6 +75,7 @@ static void *tpm2_bios_measurements_start(struct seq_file *m, loff_t *pos)
static void *tpm2_bios_measurements_next(struct seq_file *m, void *v,
loff_t *pos)
{
+ struct tcg_efi_specid_event *efispecid;
struct tcg_pcr_event *event_header;
struct tcg_pcr_event2 *event;
struct tpm_chip *chip = m->private;
@@ -144,6 +85,7 @@ static void *tpm2_bios_measurements_next(struct seq_file *m, void *v,
void *marker;

event_header = log->bios_event_log;
+ efispecid = (struct tcg_efi_specid_event *) event_header->event;

if (v == SEQ_START_TOKEN) {
event_size = sizeof(struct tcg_pcr_event) -
@@ -151,8 +93,8 @@ static void *tpm2_bios_measurements_next(struct seq_file *m, void *v,
marker = event_header;
} else {
event = v;
- event_size = calc_tpm2_event_size(event, event_header);
- if (event_size == 0)
+ event_size = calc_tpm2_event_size(event, efispecid);
+ if (event_size < 0)
return NULL;
marker = event;
}
@@ -163,8 +105,8 @@ static void *tpm2_bios_measurements_next(struct seq_file *m, void *v,
v = marker;
event = v;

- event_size = calc_tpm2_event_size(event, event_header);
- if (((v + event_size) >= limit) || (event_size == 0))
+ event_size = calc_tpm2_event_size(event, efispecid);
+ if (((v + event_size) >= limit) || (event_size < 0))
return NULL;

(*pos)++;
@@ -180,10 +122,13 @@ static int tpm2_binary_bios_measurements_show(struct seq_file *m, void *v)
struct tpm_chip *chip = m->private;
struct tpm_bios_log *log = &chip->log;
struct tcg_pcr_event *event_header = log->bios_event_log;
+ struct tcg_efi_specid_event *efispecid;
struct tcg_pcr_event2 *event = v;
void *temp_ptr;
size_t size;

+ efispecid = (struct tcg_efi_specid_event *) event_header->event;
+
if (v == SEQ_START_TOKEN) {
size = sizeof(struct tcg_pcr_event) -
sizeof(event_header->event) + event_header->event_size;
@@ -193,7 +138,7 @@ static int tpm2_binary_bios_measurements_show(struct seq_file *m, void *v)
if (size > 0)
seq_write(m, temp_ptr, size);
} else {
- size = calc_tpm2_event_size(event, event_header);
+ size = calc_tpm2_event_size(event, efispecid);
temp_ptr = event;
if (size > 0)
seq_write(m, temp_ptr, size);
diff --git a/include/linux/tpm_eventlog.h b/include/linux/tpm_eventlog.h
index 20d9da77fc11..872ab1545456 100644
--- a/include/linux/tpm_eventlog.h
+++ b/include/linux/tpm_eventlog.h
@@ -121,4 +121,7 @@ struct tcg_pcr_event2 {
struct tcg_event_field event;
} __packed;

+ssize_t calc_tpm2_event_size(struct tcg_pcr_event2 *event,
+ struct tcg_efi_specid_event *efispecid);
+
#endif
diff --git a/lib/Makefile b/lib/Makefile
index e1b59da71418..4458d914f40b 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -276,3 +276,5 @@ obj-$(CONFIG_GENERIC_LIB_MULDI3) += muldi3.o
obj-$(CONFIG_GENERIC_LIB_CMPDI2) += cmpdi2.o
obj-$(CONFIG_GENERIC_LIB_UCMPDI2) += ucmpdi2.o
obj-$(CONFIG_OBJAGG) += objagg.o
+
+obj-$(CONFIG_TCG_TPM) += tpm.o
--
2.14.4
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