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alistair23-linux/drivers/char/tpm/tpm-interface.c
James Bottomley 2be8ffed09 tpm: fix intermittent failure with self tests 
My Nuvoton 6xx in a Dell XPS-13 has been intermittently failing to work
(necessitating a reboot). The problem seems to be that the TPM gets into a
state where the partial self-test doesn't return TPM_RC_SUCCESS (meaning
all tests have run to completion), but instead returns TPM_RC_TESTING
(meaning some tests are still running in the background).  There are
various theories that resending the self-test command actually causes the
tests to restart and thus triggers more TPM_RC_TESTING returns until the
timeout is exceeded.

There are several issues here: firstly being we shouldn't slow down the
boot sequence waiting for the self test to complete once the TPM
backgrounds them.  It will actually make available all functions that have
passed and if it gets a failure return TPM_RC_FAILURE to every subsequent
command.  So the fix is to kick off self tests once and if they return
TPM_RC_TESTING log that as a backgrounded self test and continue on.  In
order to prevent other tpm users from seeing any TPM_RC_TESTING returns
(which it might if they send a command that needs a TPM subsystem which is
still under test), we loop in tpm_transmit_cmd until either a timeout or we
don't get a TPM_RC_TESTING return.

Finally, there have been observations of strange returns from a partial
test. One Nuvoton is occasionally returning TPM_RC_COMMAND_CODE, so treat
any unexpected return from a partial self test as an indication we need to
run a full self test.

[jarkko.sakkinen@linux.intel.com: cleaned up some klog messages and
 dropped tpm_transmit_check() helper function from James' original
 commit.]

Fixes: 2482b1bba5 ("tpm: Trigger only missing TPM 2.0 self tests")
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>
2018-03-23 10:25:09 +02:00

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/*
* Copyright (C) 2004 IBM Corporation
* Copyright (C) 2014 Intel Corporation
*
* Authors:
* Leendert van Doorn <leendert@watson.ibm.com>
* Dave Safford <safford@watson.ibm.com>
* Reiner Sailer <sailer@watson.ibm.com>
* Kylene Hall <kjhall@us.ibm.com>
*
* Maintained by: <tpmdd-devel@lists.sourceforge.net>
*
* Device driver for TCG/TCPA TPM (trusted platform module).
* Specifications at www.trustedcomputinggroup.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*
* Note, the TPM chip is not interrupt driven (only polling)
* and can have very long timeouts (minutes!). Hence the unusual
* calls to msleep.
*
*/
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/freezer.h>
#include <linux/pm_runtime.h>
#include <linux/tpm_eventlog.h>
#include "tpm.h"
#define TPM_MAX_ORDINAL 243
#define TSC_MAX_ORDINAL 12
#define TPM_PROTECTED_COMMAND 0x00
#define TPM_CONNECTION_COMMAND 0x40
/*
* Bug workaround - some TPM's don't flush the most
* recently changed pcr on suspend, so force the flush
* with an extend to the selected _unused_ non-volatile pcr.
*/
static int tpm_suspend_pcr;
module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
MODULE_PARM_DESC(suspend_pcr,
"PCR to use for dummy writes to facilitate flush on suspend.");
/*
* Array with one entry per ordinal defining the maximum amount
* of time the chip could take to return the result. The ordinal
* designation of short, medium or long is defined in a table in
* TCG Specification TPM Main Part 2 TPM Structures Section 17. The
* values of the SHORT, MEDIUM, and LONG durations are retrieved
* from the chip during initialization with a call to tpm_get_timeouts.
*/
static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
TPM_UNDEFINED, /* 0 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED, /* 5 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_SHORT, /* 10 */
TPM_SHORT,
TPM_MEDIUM,
TPM_LONG,
TPM_LONG,
TPM_MEDIUM, /* 15 */
TPM_SHORT,
TPM_SHORT,
TPM_MEDIUM,
TPM_LONG,
TPM_SHORT, /* 20 */
TPM_SHORT,
TPM_MEDIUM,
TPM_MEDIUM,
TPM_MEDIUM,
TPM_SHORT, /* 25 */
TPM_SHORT,
TPM_MEDIUM,
TPM_SHORT,
TPM_SHORT,
TPM_MEDIUM, /* 30 */
TPM_LONG,
TPM_MEDIUM,
TPM_SHORT,
TPM_SHORT,
TPM_SHORT, /* 35 */
TPM_MEDIUM,
TPM_MEDIUM,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_MEDIUM, /* 40 */
TPM_LONG,
TPM_MEDIUM,
TPM_SHORT,
TPM_SHORT,
TPM_SHORT, /* 45 */
TPM_SHORT,
TPM_SHORT,
TPM_SHORT,
TPM_LONG,
TPM_MEDIUM, /* 50 */
TPM_MEDIUM,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED, /* 55 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_MEDIUM, /* 60 */
TPM_MEDIUM,
TPM_MEDIUM,
TPM_SHORT,
TPM_SHORT,
TPM_MEDIUM, /* 65 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_SHORT, /* 70 */
TPM_SHORT,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED, /* 75 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_LONG, /* 80 */
TPM_UNDEFINED,
TPM_MEDIUM,
TPM_LONG,
TPM_SHORT,
TPM_UNDEFINED, /* 85 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_SHORT, /* 90 */
TPM_SHORT,
TPM_SHORT,
TPM_SHORT,
TPM_SHORT,
TPM_UNDEFINED, /* 95 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_MEDIUM, /* 100 */
TPM_SHORT,
TPM_SHORT,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED, /* 105 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_SHORT, /* 110 */
TPM_SHORT,
TPM_SHORT,
TPM_SHORT,
TPM_SHORT,
TPM_SHORT, /* 115 */
TPM_SHORT,
TPM_SHORT,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_LONG, /* 120 */
TPM_LONG,
TPM_MEDIUM,
TPM_UNDEFINED,
TPM_SHORT,
TPM_SHORT, /* 125 */
TPM_SHORT,
TPM_LONG,
TPM_SHORT,
TPM_SHORT,
TPM_SHORT, /* 130 */
TPM_MEDIUM,
TPM_UNDEFINED,
TPM_SHORT,
TPM_MEDIUM,
TPM_UNDEFINED, /* 135 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_SHORT, /* 140 */
TPM_SHORT,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED, /* 145 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_SHORT, /* 150 */
TPM_MEDIUM,
TPM_MEDIUM,
TPM_SHORT,
TPM_SHORT,
TPM_UNDEFINED, /* 155 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_SHORT, /* 160 */
TPM_SHORT,
TPM_SHORT,
TPM_SHORT,
TPM_UNDEFINED,
TPM_UNDEFINED, /* 165 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_LONG, /* 170 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED, /* 175 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_MEDIUM, /* 180 */
TPM_SHORT,
TPM_MEDIUM,
TPM_MEDIUM,
TPM_MEDIUM,
TPM_MEDIUM, /* 185 */
TPM_SHORT,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED, /* 190 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED, /* 195 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_SHORT, /* 200 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_SHORT,
TPM_SHORT, /* 205 */
TPM_SHORT,
TPM_SHORT,
TPM_SHORT,
TPM_SHORT,
TPM_MEDIUM, /* 210 */
TPM_UNDEFINED,
TPM_MEDIUM,
TPM_MEDIUM,
TPM_MEDIUM,
TPM_UNDEFINED, /* 215 */
TPM_MEDIUM,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_SHORT,
TPM_SHORT, /* 220 */
TPM_SHORT,
TPM_SHORT,
TPM_SHORT,
TPM_SHORT,
TPM_UNDEFINED, /* 225 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_SHORT, /* 230 */
TPM_LONG,
TPM_MEDIUM,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED, /* 235 */
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_UNDEFINED,
TPM_SHORT, /* 240 */
TPM_UNDEFINED,
TPM_MEDIUM,
};
/*
* Returns max number of jiffies to wait
*/
unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
u32 ordinal)
{
int duration_idx = TPM_UNDEFINED;
int duration = 0;
/*
* We only have a duration table for protected commands, where the upper
* 16 bits are 0. For the few other ordinals the fallback will be used.
*/
if (ordinal < TPM_MAX_ORDINAL)
duration_idx = tpm_ordinal_duration[ordinal];
if (duration_idx != TPM_UNDEFINED)
duration = chip->duration[duration_idx];
if (duration <= 0)
return 2 * 60 * HZ;
else
return duration;
}
EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
static int tpm_validate_command(struct tpm_chip *chip,
struct tpm_space *space,
const u8 *cmd,
size_t len)
{
const struct tpm_input_header *header = (const void *)cmd;
int i;
u32 cc;
u32 attrs;
unsigned int nr_handles;
if (len < TPM_HEADER_SIZE)
return -EINVAL;
if (!space)
return 0;
if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) {
cc = be32_to_cpu(header->ordinal);
i = tpm2_find_cc(chip, cc);
if (i < 0) {
dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
cc);
return -EOPNOTSUPP;
}
attrs = chip->cc_attrs_tbl[i];
nr_handles =
4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
if (len < TPM_HEADER_SIZE + 4 * nr_handles)
goto err_len;
}
return 0;
err_len:
dev_dbg(&chip->dev,
"%s: insufficient command length %zu", __func__, len);
return -EINVAL;
}
static int tpm_request_locality(struct tpm_chip *chip)
{
int rc;
if (!chip->ops->request_locality)
return 0;
rc = chip->ops->request_locality(chip, 0);
if (rc < 0)
return rc;
chip->locality = rc;
return 0;
}
static void tpm_relinquish_locality(struct tpm_chip *chip)
{
int rc;
if (!chip->ops->relinquish_locality)
return;
rc = chip->ops->relinquish_locality(chip, chip->locality);
if (rc)
dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
chip->locality = -1;
}
static ssize_t tpm_try_transmit(struct tpm_chip *chip,
struct tpm_space *space,
u8 *buf, size_t bufsiz,
unsigned int flags)
{
struct tpm_output_header *header = (void *)buf;
int rc;
ssize_t len = 0;
u32 count, ordinal;
unsigned long stop;
bool need_locality;
rc = tpm_validate_command(chip, space, buf, bufsiz);
if (rc == -EINVAL)
return rc;
/*
* If the command is not implemented by the TPM, synthesize a
* response with a TPM2_RC_COMMAND_CODE return for user-space.
*/
if (rc == -EOPNOTSUPP) {
header->length = cpu_to_be32(sizeof(*header));
header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE |
TSS2_RESMGR_TPM_RC_LAYER);
return bufsiz;
}
if (bufsiz > TPM_BUFSIZE)
bufsiz = TPM_BUFSIZE;
count = be32_to_cpu(*((__be32 *) (buf + 2)));
ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
if (count == 0)
return -ENODATA;
if (count > bufsiz) {
dev_err(&chip->dev,
"invalid count value %x %zx\n", count, bufsiz);
return -E2BIG;
}
if (!(flags & TPM_TRANSMIT_UNLOCKED))
mutex_lock(&chip->tpm_mutex);
if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, true);
/* Store the decision as chip->locality will be changed. */
need_locality = chip->locality == -1;
if (!(flags & TPM_TRANSMIT_RAW) && need_locality) {
rc = tpm_request_locality(chip);
if (rc < 0)
goto out_no_locality;
}
if (chip->dev.parent)
pm_runtime_get_sync(chip->dev.parent);
rc = tpm2_prepare_space(chip, space, ordinal, buf);
if (rc)
goto out;
rc = chip->ops->send(chip, buf, count);
if (rc < 0) {
if (rc != -EPIPE)
dev_err(&chip->dev,
"%s: tpm_send: error %d\n", __func__, rc);
goto out;
}
if (chip->flags & TPM_CHIP_FLAG_IRQ)
goto out_recv;
if (chip->flags & TPM_CHIP_FLAG_TPM2)
stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
else
stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
do {
u8 status = chip->ops->status(chip);
if ((status & chip->ops->req_complete_mask) ==
chip->ops->req_complete_val)
goto out_recv;
if (chip->ops->req_canceled(chip, status)) {
dev_err(&chip->dev, "Operation Canceled\n");
rc = -ECANCELED;
goto out;
}
tpm_msleep(TPM_TIMEOUT);
rmb();
} while (time_before(jiffies, stop));
chip->ops->cancel(chip);
dev_err(&chip->dev, "Operation Timed out\n");
rc = -ETIME;
goto out;
out_recv:
len = chip->ops->recv(chip, buf, bufsiz);
if (len < 0) {
rc = len;
dev_err(&chip->dev,
"tpm_transmit: tpm_recv: error %d\n", rc);
goto out;
} else if (len < TPM_HEADER_SIZE) {
rc = -EFAULT;
goto out;
}
if (len != be32_to_cpu(header->length)) {
rc = -EFAULT;
goto out;
}
rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
out:
if (chip->dev.parent)
pm_runtime_put_sync(chip->dev.parent);
if (need_locality)
tpm_relinquish_locality(chip);
out_no_locality:
if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, false);
if (!(flags & TPM_TRANSMIT_UNLOCKED))
mutex_unlock(&chip->tpm_mutex);
return rc ? rc : len;
}
/**
* tpm_transmit - Internal kernel interface to transmit TPM commands.
*
* @chip: TPM chip to use
* @space: tpm space
* @buf: TPM command buffer
* @bufsiz: length of the TPM command buffer
* @flags: tpm transmit flags - bitmap
*
* A wrapper around tpm_try_transmit that handles TPM2_RC_RETRY
* returns from the TPM and retransmits the command after a delay up
* to a maximum wait of TPM2_DURATION_LONG.
*
* Note: TPM1 never returns TPM2_RC_RETRY so the retry logic is TPM2
* only
*
* Return:
* the length of the return when the operation is successful.
* A negative number for system errors (errno).
*/
ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
u8 *buf, size_t bufsiz, unsigned int flags)
{
struct tpm_output_header *header = (struct tpm_output_header *)buf;
/* space for header and handles */
u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
unsigned int delay_msec = TPM2_DURATION_SHORT;
u32 rc = 0;
ssize_t ret;
const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE,
bufsiz);
/* the command code is where the return code will be */
u32 cc = be32_to_cpu(header->return_code);
/*
* Subtlety here: if we have a space, the handles will be
* transformed, so when we restore the header we also have to
* restore the handles.
*/
memcpy(save, buf, save_size);
for (;;) {
ret = tpm_try_transmit(chip, space, buf, bufsiz, flags);
if (ret < 0)
break;
rc = be32_to_cpu(header->return_code);
if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING)
break;
/*
* return immediately if self test returns test
* still running to shorten boot time.
*/
if (rc == TPM2_RC_TESTING && cc == TPM2_CC_SELF_TEST)
break;
delay_msec *= 2;
if (delay_msec > TPM2_DURATION_LONG) {
if (rc == TPM2_RC_RETRY)
dev_err(&chip->dev, "in retry loop\n");
else
dev_err(&chip->dev,
"self test is still running\n");
break;
}
tpm_msleep(delay_msec);
memcpy(buf, save, save_size);
}
return ret;
}
/**
* tpm_transmit_cmd - send a tpm command to the device
* The function extracts tpm out header return code
*
* @chip: TPM chip to use
* @space: tpm space
* @buf: TPM command buffer
* @bufsiz: length of the buffer
* @min_rsp_body_length: minimum expected length of response body
* @flags: tpm transmit flags - bitmap
* @desc: command description used in the error message
*
* Return:
* 0 when the operation is successful.
* A negative number for system errors (errno).
* A positive number for a TPM error.
*/
ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
void *buf, size_t bufsiz,
size_t min_rsp_body_length, unsigned int flags,
const char *desc)
{
const struct tpm_output_header *header = buf;
int err;
ssize_t len;
len = tpm_transmit(chip, space, buf, bufsiz, flags);
if (len < 0)
return len;
err = be32_to_cpu(header->return_code);
if (err != 0 && desc)
dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
desc);
if (err)
return err;
if (len < min_rsp_body_length + TPM_HEADER_SIZE)
return -EFAULT;
return 0;
}
EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
#define TPM_ORD_STARTUP 153
#define TPM_ST_CLEAR 1
/**
* tpm_startup - turn on the TPM
* @chip: TPM chip to use
*
* Normally the firmware should start the TPM. This function is provided as a
* workaround if this does not happen. A legal case for this could be for
* example when a TPM emulator is used.
*
* Return: same as tpm_transmit_cmd()
*/
int tpm_startup(struct tpm_chip *chip)
{
struct tpm_buf buf;
int rc;
dev_info(&chip->dev, "starting up the TPM manually\n");
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
if (rc < 0)
return rc;
tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
} else {
rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_STARTUP);
if (rc < 0)
return rc;
tpm_buf_append_u16(&buf, TPM_ST_CLEAR);
}
rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
"attempting to start the TPM");
tpm_buf_destroy(&buf);
return rc;
}
#define TPM_DIGEST_SIZE 20
#define TPM_RET_CODE_IDX 6
#define TPM_INTERNAL_RESULT_SIZE 200
#define TPM_ORD_GET_CAP 101
#define TPM_ORD_GET_RANDOM 70
static const struct tpm_input_header tpm_getcap_header = {
.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
.length = cpu_to_be32(22),
.ordinal = cpu_to_be32(TPM_ORD_GET_CAP)
};
ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
const char *desc, size_t min_cap_length)
{
struct tpm_buf buf;
int rc;
rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_CAP);
if (rc)
return rc;
if (subcap_id == TPM_CAP_VERSION_1_1 ||
subcap_id == TPM_CAP_VERSION_1_2) {
tpm_buf_append_u32(&buf, subcap_id);
tpm_buf_append_u32(&buf, 0);
} else {
if (subcap_id == TPM_CAP_FLAG_PERM ||
subcap_id == TPM_CAP_FLAG_VOL)
tpm_buf_append_u32(&buf, TPM_CAP_FLAG);
else
tpm_buf_append_u32(&buf, TPM_CAP_PROP);
tpm_buf_append_u32(&buf, 4);
tpm_buf_append_u32(&buf, subcap_id);
}
rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
min_cap_length, 0, desc);
if (!rc)
*cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
tpm_buf_destroy(&buf);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_getcap);
int tpm_get_timeouts(struct tpm_chip *chip)
{
cap_t cap;
unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
ssize_t rc;
if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
return 0;
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
/* Fixed timeouts for TPM2 */
chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
chip->duration[TPM_SHORT] =
msecs_to_jiffies(TPM2_DURATION_SHORT);
chip->duration[TPM_MEDIUM] =
msecs_to_jiffies(TPM2_DURATION_MEDIUM);
chip->duration[TPM_LONG] =
msecs_to_jiffies(TPM2_DURATION_LONG);
chip->duration[TPM_LONG_LONG] =
msecs_to_jiffies(TPM2_DURATION_LONG_LONG);
chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
return 0;
}
rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
sizeof(cap.timeout));
if (rc == TPM_ERR_INVALID_POSTINIT) {
if (tpm_startup(chip))
return rc;
rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
"attempting to determine the timeouts",
sizeof(cap.timeout));
}
if (rc) {
dev_err(&chip->dev,
"A TPM error (%zd) occurred attempting to determine the timeouts\n",
rc);
return rc;
}
timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
timeout_chip[0] = be32_to_cpu(cap.timeout.a);
timeout_chip[1] = be32_to_cpu(cap.timeout.b);
timeout_chip[2] = be32_to_cpu(cap.timeout.c);
timeout_chip[3] = be32_to_cpu(cap.timeout.d);
memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
/*
* Provide ability for vendor overrides of timeout values in case
* of misreporting.
*/
if (chip->ops->update_timeouts != NULL)
chip->timeout_adjusted =
chip->ops->update_timeouts(chip, timeout_eff);
if (!chip->timeout_adjusted) {
/* Restore default if chip reported 0 */
int i;
for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
if (timeout_eff[i])
continue;
timeout_eff[i] = timeout_old[i];
chip->timeout_adjusted = true;
}
if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
/* timeouts in msec rather usec */
for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
timeout_eff[i] *= 1000;
chip->timeout_adjusted = true;
}
}
/* Report adjusted timeouts */
if (chip->timeout_adjusted) {
dev_info(&chip->dev,
HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
timeout_chip[0], timeout_eff[0],
timeout_chip[1], timeout_eff[1],
timeout_chip[2], timeout_eff[2],
timeout_chip[3], timeout_eff[3]);
}
chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
"attempting to determine the durations",
sizeof(cap.duration));
if (rc)
return rc;
chip->duration[TPM_SHORT] =
usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
chip->duration[TPM_MEDIUM] =
usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
chip->duration[TPM_LONG] =
usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
chip->duration[TPM_LONG_LONG] = 0; /* not used under 1.2 */
/* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
* value wrong and apparently reports msecs rather than usecs. So we
* fix up the resulting too-small TPM_SHORT value to make things work.
* We also scale the TPM_MEDIUM and -_LONG values by 1000.
*/
if (chip->duration[TPM_SHORT] < (HZ / 100)) {
chip->duration[TPM_SHORT] = HZ;
chip->duration[TPM_MEDIUM] *= 1000;
chip->duration[TPM_LONG] *= 1000;
chip->duration_adjusted = true;
dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
}
chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
return 0;
}
EXPORT_SYMBOL_GPL(tpm_get_timeouts);
#define TPM_ORD_CONTINUE_SELFTEST 83
#define CONTINUE_SELFTEST_RESULT_SIZE 10
static const struct tpm_input_header continue_selftest_header = {
.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
.length = cpu_to_be32(10),
.ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
};
/**
* tpm_continue_selftest -- run TPM's selftest
* @chip: TPM chip to use
*
* Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
* a TPM error code.
*/
static int tpm_continue_selftest(struct tpm_chip *chip)
{
int rc;
struct tpm_cmd_t cmd;
cmd.header.in = continue_selftest_header;
rc = tpm_transmit_cmd(chip, NULL, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
0, 0, "continue selftest");
return rc;
}
#define TPM_ORDINAL_PCRREAD 21
#define READ_PCR_RESULT_SIZE 30
#define READ_PCR_RESULT_BODY_SIZE 20
static const struct tpm_input_header pcrread_header = {
.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
.length = cpu_to_be32(14),
.ordinal = cpu_to_be32(TPM_ORDINAL_PCRREAD)
};
int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
{
int rc;
struct tpm_cmd_t cmd;
cmd.header.in = pcrread_header;
cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
rc = tpm_transmit_cmd(chip, NULL, &cmd, READ_PCR_RESULT_SIZE,
READ_PCR_RESULT_BODY_SIZE, 0,
"attempting to read a pcr value");
if (rc == 0)
memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
TPM_DIGEST_SIZE);
return rc;
}
/**
* tpm_is_tpm2 - do we a have a TPM2 chip?
* @chip: a &struct tpm_chip instance, %NULL for the default chip
*
* Return:
* 1 if we have a TPM2 chip.
* 0 if we don't have a TPM2 chip.
* A negative number for system errors (errno).
*/
int tpm_is_tpm2(struct tpm_chip *chip)
{
int rc;
chip = tpm_chip_find_get(chip);
if (!chip)
return -ENODEV;
rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
tpm_put_ops(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_is_tpm2);
/**
* tpm_pcr_read - read a PCR value from SHA1 bank
* @chip: a &struct tpm_chip instance, %NULL for the default chip
* @pcr_idx: the PCR to be retrieved
* @res_buf: the value of the PCR
*
* Return: same as with tpm_transmit_cmd()
*/
int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
{
int rc;
chip = tpm_chip_find_get(chip);
if (!chip)
return -ENODEV;
if (chip->flags & TPM_CHIP_FLAG_TPM2)
rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
else
rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
tpm_put_ops(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_pcr_read);
#define TPM_ORD_PCR_EXTEND 20
#define EXTEND_PCR_RESULT_SIZE 34
#define EXTEND_PCR_RESULT_BODY_SIZE 20
static const struct tpm_input_header pcrextend_header = {
.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
.length = cpu_to_be32(34),
.ordinal = cpu_to_be32(TPM_ORD_PCR_EXTEND)
};
static int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash,
char *log_msg)
{
struct tpm_buf buf;
int rc;
rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_EXTEND);
if (rc)
return rc;
tpm_buf_append_u32(&buf, pcr_idx);
tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE);
rc = tpm_transmit_cmd(chip, NULL, buf.data, EXTEND_PCR_RESULT_SIZE,
EXTEND_PCR_RESULT_BODY_SIZE, 0, log_msg);
tpm_buf_destroy(&buf);
return rc;
}
/**
* tpm_pcr_extend - extend a PCR value in SHA1 bank.
* @chip: a &struct tpm_chip instance, %NULL for the default chip
* @pcr_idx: the PCR to be retrieved
* @hash: the hash value used to extend the PCR value
*
* Note: with TPM 2.0 extends also those banks with a known digest size to the
* cryto subsystem in order to prevent malicious use of those PCR banks. In the
* future we should dynamically determine digest sizes.
*
* Return: same as with tpm_transmit_cmd()
*/
int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
{
int rc;
struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];
u32 count = 0;
int i;
chip = tpm_chip_find_get(chip);
if (!chip)
return -ENODEV;
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
memset(digest_list, 0, sizeof(digest_list));
for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
digest_list[i].alg_id = chip->active_banks[i];
memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
count++;
}
rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list);
tpm_put_ops(chip);
return rc;
}
rc = tpm1_pcr_extend(chip, pcr_idx, hash,
"attempting extend a PCR value");
tpm_put_ops(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_pcr_extend);
/**
* tpm_do_selftest - have the TPM continue its selftest and wait until it
* can receive further commands
* @chip: TPM chip to use
*
* Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
* a TPM error code.
*/
int tpm_do_selftest(struct tpm_chip *chip)
{
int rc;
unsigned int loops;
unsigned int delay_msec = 100;
unsigned long duration;
u8 dummy[TPM_DIGEST_SIZE];
duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
loops = jiffies_to_msecs(duration) / delay_msec;
rc = tpm_continue_selftest(chip);
if (rc == TPM_ERR_INVALID_POSTINIT) {
chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
dev_info(&chip->dev, "TPM not ready (%d)\n", rc);
}
/* This may fail if there was no TPM driver during a suspend/resume
* cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
*/
if (rc)
return rc;
do {
/* Attempt to read a PCR value */
rc = tpm_pcr_read_dev(chip, 0, dummy);
/* Some buggy TPMs will not respond to tpm_tis_ready() for
* around 300ms while the self test is ongoing, keep trying
* until the self test duration expires. */
if (rc == -ETIME) {
dev_info(
&chip->dev, HW_ERR
"TPM command timed out during continue self test");
tpm_msleep(delay_msec);
continue;
}
if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
dev_info(&chip->dev,
"TPM is disabled/deactivated (0x%X)\n", rc);
/* TPM is disabled and/or deactivated; driver can
* proceed and TPM does handle commands for
* suspend/resume correctly
*/
return 0;
}
if (rc != TPM_WARN_DOING_SELFTEST)
return rc;
tpm_msleep(delay_msec);
} while (--loops > 0);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_do_selftest);
/**
* tpm1_auto_startup - Perform the standard automatic TPM initialization
* sequence
* @chip: TPM chip to use
*
* Returns 0 on success, < 0 in case of fatal error.
*/
int tpm1_auto_startup(struct tpm_chip *chip)
{
int rc;
rc = tpm_get_timeouts(chip);
if (rc)
goto out;
rc = tpm_do_selftest(chip);
if (rc) {
dev_err(&chip->dev, "TPM self test failed\n");
goto out;
}
return rc;
out:
if (rc > 0)
rc = -ENODEV;
return rc;
}
/**
* tpm_send - send a TPM command
* @chip: a &struct tpm_chip instance, %NULL for the default chip
* @cmd: a TPM command buffer
* @buflen: the length of the TPM command buffer
*
* Return: same as with tpm_transmit_cmd()
*/
int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
{
int rc;
chip = tpm_chip_find_get(chip);
if (!chip)
return -ENODEV;
rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, 0,
"attempting to a send a command");
tpm_put_ops(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_send);
#define TPM_ORD_SAVESTATE 152
#define SAVESTATE_RESULT_SIZE 10
static const struct tpm_input_header savestate_header = {
.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
.length = cpu_to_be32(10),
.ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)
};
/*
* We are about to suspend. Save the TPM state
* so that it can be restored.
*/
int tpm_pm_suspend(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
struct tpm_cmd_t cmd;
int rc, try;
u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
if (chip == NULL)
return -ENODEV;
if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
return 0;
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
tpm2_shutdown(chip, TPM2_SU_STATE);
return 0;
}
/* for buggy tpm, flush pcrs with extend to selected dummy */
if (tpm_suspend_pcr)
rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
"extending dummy pcr before suspend");
/* now do the actual savestate */
for (try = 0; try < TPM_RETRY; try++) {
cmd.header.in = savestate_header;
rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,
0, 0, NULL);
/*
* If the TPM indicates that it is too busy to respond to
* this command then retry before giving up. It can take
* several seconds for this TPM to be ready.
*
* This can happen if the TPM has already been sent the
* SaveState command before the driver has loaded. TCG 1.2
* specification states that any communication after SaveState
* may cause the TPM to invalidate previously saved state.
*/
if (rc != TPM_WARN_RETRY)
break;
tpm_msleep(TPM_TIMEOUT_RETRY);
}
if (rc)
dev_err(&chip->dev,
"Error (%d) sending savestate before suspend\n", rc);
else if (try > 0)
dev_warn(&chip->dev, "TPM savestate took %dms\n",
try * TPM_TIMEOUT_RETRY);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_pm_suspend);
/*
* Resume from a power safe. The BIOS already restored
* the TPM state.
*/
int tpm_pm_resume(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
if (chip == NULL)
return -ENODEV;
return 0;
}
EXPORT_SYMBOL_GPL(tpm_pm_resume);
#define TPM_GETRANDOM_RESULT_SIZE 18
static const struct tpm_input_header tpm_getrandom_header = {
.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
.length = cpu_to_be32(14),
.ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
};
/**
* tpm_get_random() - get random bytes from the TPM's RNG
* @chip: a &struct tpm_chip instance, %NULL for the default chip
* @out: destination buffer for the random bytes
* @max: the max number of bytes to write to @out
*
* Return: same as with tpm_transmit_cmd()
*/
int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
{
struct tpm_cmd_t tpm_cmd;
u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;
int err, total = 0, retries = 5;
u8 *dest = out;
if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
return -EINVAL;
chip = tpm_chip_find_get(chip);
if (!chip)
return -ENODEV;
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
err = tpm2_get_random(chip, out, max);
tpm_put_ops(chip);
return err;
}
do {
tpm_cmd.header.in = tpm_getrandom_header;
tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
TPM_GETRANDOM_RESULT_SIZE + num_bytes,
offsetof(struct tpm_getrandom_out,
rng_data),
0, "attempting get random");
if (err)
break;
recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
if (recd > num_bytes) {
total = -EFAULT;
break;
}
rlength = be32_to_cpu(tpm_cmd.header.out.length);
if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +
recd) {
total = -EFAULT;
break;
}
memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
dest += recd;
total += recd;
num_bytes -= recd;
} while (retries-- && total < max);
tpm_put_ops(chip);
return total ? total : -EIO;
}
EXPORT_SYMBOL_GPL(tpm_get_random);
/**
* tpm_seal_trusted() - seal a trusted key payload
* @chip: a &struct tpm_chip instance, %NULL for the default chip
* @options: authentication values and other options
* @payload: the key data in clear and encrypted form
*
* Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
* the keyring subsystem.
*
* Return: same as with tpm_transmit_cmd()
*/
int tpm_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
int rc;
chip = tpm_chip_find_get(chip);
if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
return -ENODEV;
rc = tpm2_seal_trusted(chip, payload, options);
tpm_put_ops(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_seal_trusted);
/**
* tpm_unseal_trusted() - unseal a trusted key
* @chip: a &struct tpm_chip instance, %NULL for the default chip
* @options: authentication values and other options
* @payload: the key data in clear and encrypted form
*
* Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
* the keyring subsystem.
*
* Return: same as with tpm_transmit_cmd()
*/
int tpm_unseal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
int rc;
chip = tpm_chip_find_get(chip);
if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
return -ENODEV;
rc = tpm2_unseal_trusted(chip, payload, options);
tpm_put_ops(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
static int __init tpm_init(void)
{
int rc;
tpm_class = class_create(THIS_MODULE, "tpm");
if (IS_ERR(tpm_class)) {
pr_err("couldn't create tpm class\n");
return PTR_ERR(tpm_class);
}
tpmrm_class = class_create(THIS_MODULE, "tpmrm");
if (IS_ERR(tpmrm_class)) {
pr_err("couldn't create tpmrm class\n");
class_destroy(tpm_class);
return PTR_ERR(tpmrm_class);
}
rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm");
if (rc < 0) {
pr_err("tpm: failed to allocate char dev region\n");
class_destroy(tpmrm_class);
class_destroy(tpm_class);
return rc;
}
return 0;
}
static void __exit tpm_exit(void)
{
idr_destroy(&dev_nums_idr);
class_destroy(tpm_class);
class_destroy(tpmrm_class);
unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
}
subsys_initcall(tpm_init);
module_exit(tpm_exit);
MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
MODULE_DESCRIPTION("TPM Driver");
MODULE_VERSION("2.0");
MODULE_LICENSE("GPL");
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