[PATCH v9 01/17] tpm: use tpm_buf in tpm_transmit_cmd() as the IO parameter

Jarkko Sakkinen
2018-11-18T12:48:14Z

Since we pass an initialized struct tpm_buf instance in every call site
now, it is cleaner to pass that directly to the tpm_transmit_cmd() as
the TPM command/response buffer.

Fine-tune a little bit tpm_transmit() and tpm_transmit_cmd() comments
while doing this.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
---
drivers/char/tpm/tpm-interface.c | 67 +++++++++++++++++--------------
drivers/char/tpm/tpm-sysfs.c | 2 +-
drivers/char/tpm/tpm.h | 5 +--
drivers/char/tpm/tpm1-cmd.c | 26 ++++--------
drivers/char/tpm/tpm2-cmd.c | 37 +++++++----------
drivers/char/tpm/tpm2-space.c | 4 +-
drivers/char/tpm/tpm_vtpm_proxy.c | 3 +-
7 files changed, 64 insertions(+), 80 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index d9439f9abe78..64510ed81b46 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -298,23 +298,22 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,

/**
* tpm_transmit - Internal kernel interface to transmit TPM commands.
+ * @chip: a TPM chip to use
+ * @space: a TPM space
+ * @buf: a TPM command buffer
+ * @bufsiz: length of the TPM command buffer
+ * @flags: TPM transmit flags
*
- * @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.
*
- * 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
+ * Note that TPM 1.x never returns TPM2_RC_RETRY so the retry logic is TPM 2.0
+ * only.
*
* Return:
- * the length of the return when the operation is successful.
- * A negative number for system errors (errno).
+ * * The response length - OK
+ * * -errno - A system error
*/
ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
u8 *buf, size_t bufsiz, unsigned int flags)
@@ -365,33 +364,31 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
}
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
+ * @chip: a TPM chip to use
+ * @space: a TPM space
+ * @buf: a TPM command buffer
+ * @min_rsp_body_length: minimum expected length of response body
+ * @flags: TPM transmit flags
+ * @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.
+ * * 0 - OK
+ * * -errno - A system error
+ * * TPM_RC - 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)
+ struct tpm_buf *buf, size_t min_rsp_body_length,
+ unsigned int flags, const char *desc)
{
- const struct tpm_output_header *header = buf;
+ const struct tpm_output_header *header =
+ (struct tpm_output_header *)buf->data;
int err;
ssize_t len;

- len = tpm_transmit(chip, space, buf, bufsiz, flags);
+ len = tpm_transmit(chip, space, buf->data, PAGE_SIZE, flags);
if (len < 0)
return len;

@@ -528,14 +525,22 @@ EXPORT_SYMBOL_GPL(tpm_pcr_extend);
*/
int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
{
+ struct tpm_buf buf;
int rc;

chip = tpm_find_get_ops(chip);
if (!chip)
return -ENODEV;

- rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, 0,
+ rc = tpm_buf_init(&buf, 0, 0);
+ if (rc)
+ goto out;
+
+ memcpy(buf.data, cmd, buflen);
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
"attempting to a send a command");
+ tpm_buf_destroy(&buf);
+out:
tpm_put_ops(chip);
return rc;
}
diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index b88e08ec2c59..c2769e55cb6c 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -53,7 +53,7 @@ static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,

tpm_buf_append(&tpm_buf, anti_replay, sizeof(anti_replay));

- rc = tpm_transmit_cmd(chip, NULL, tpm_buf.data, PAGE_SIZE,
+ rc = tpm_transmit_cmd(chip, NULL, &tpm_buf,
READ_PUBEK_RESULT_MIN_BODY_SIZE, 0,
"attempting to read the PUBEK");
if (rc) {
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index f27d1f38a93d..49bca4d1e786 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -503,9 +503,8 @@ enum tpm_transmit_flags {
ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
u8 *buf, size_t bufsiz, unsigned int flags);
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);
+ struct tpm_buf *buf, size_t min_rsp_body_length,
+ unsigned int flags, const char *desc);
int tpm_get_timeouts(struct tpm_chip *);
int tpm_auto_startup(struct tpm_chip *chip);

diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c
index 6f306338953b..f19b7c1ff800 100644
--- a/drivers/char/tpm/tpm1-cmd.c
+++ b/drivers/char/tpm/tpm1-cmd.c
@@ -334,11 +334,9 @@ static int tpm1_startup(struct tpm_chip *chip)

tpm_buf_append_u16(&buf, TPM_ST_CLEAR);

- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
"attempting to start the TPM");
-
tpm_buf_destroy(&buf);
-
return rc;
}

@@ -462,9 +460,7 @@ int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash,
tpm_buf_append_u32(&buf, pcr_idx);
tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE);

- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
- TPM_DIGEST_SIZE, 0, log_msg);
-
+ rc = tpm_transmit_cmd(chip, NULL, &buf, TPM_DIGEST_SIZE, 0, log_msg);
tpm_buf_destroy(&buf);
return rc;
}
@@ -494,11 +490,9 @@ ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
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);
+ rc = tpm_transmit_cmd(chip, NULL, &buf, min_cap_length, 0, desc);
if (!rc)
*cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
-
tpm_buf_destroy(&buf);
return rc;
}
@@ -537,7 +531,7 @@ int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
do {
tpm_buf_append_u32(&buf, num_bytes);

- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
+ rc = tpm_transmit_cmd(chip, NULL, &buf,
sizeof(out->rng_data_len), 0,
"attempting get random");
if (rc)
@@ -583,8 +577,7 @@ int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)

tpm_buf_append_u32(&buf, pcr_idx);

- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
- TPM_DIGEST_SIZE, 0,
+ rc = tpm_transmit_cmd(chip, NULL, &buf, TPM_DIGEST_SIZE, 0,
"attempting to read a pcr value");
if (rc)
goto out;
@@ -618,11 +611,8 @@ static int tpm1_continue_selftest(struct tpm_chip *chip)
if (rc)
return rc;

- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
- 0, 0, "continue selftest");
-
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0, "continue selftest");
tpm_buf_destroy(&buf);
-
return rc;
}

@@ -747,9 +737,7 @@ int tpm1_pm_suspend(struct tpm_chip *chip, u32 tpm_suspend_pcr)
return rc;
/* now do the actual savestate */
for (try = 0; try < TPM_RETRY; try++) {
- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
- 0, 0, NULL);
-
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 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
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index a6bec13afa69..2bcf470c8e5d 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -197,8 +197,8 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
tpm_buf_append(&buf, (const unsigned char *)pcr_select,
sizeof(pcr_select));

- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
- res_buf ? "attempting to read a pcr value" : NULL);
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0, res_buf ?
+ "attempting to read a pcr value" : NULL);
if (rc == 0 && res_buf) {
out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE];
memcpy(res_buf, out->digest, SHA1_DIGEST_SIZE);
@@ -264,7 +264,7 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count,
}
}

- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
"attempting extend a PCR value");

tpm_buf_destroy(&buf);
@@ -309,7 +309,7 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
do {
tpm_buf_reset(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_RANDOM);
tpm_buf_append_u16(&buf, num_bytes);
- err = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
+ err = tpm_transmit_cmd(chip, NULL, &buf,
offsetof(struct tpm2_get_random_out,
buffer),
0, "attempting get random");
@@ -362,9 +362,7 @@ void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle,

tpm_buf_append_u32(&buf, handle);

- (void) tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, flags,
- "flushing context");
-
+ tpm_transmit_cmd(chip, NULL, &buf, 0, flags, "flushing context");
tpm_buf_destroy(&buf);
}

@@ -478,8 +476,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
goto out;
}

- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 4, 0,
- "sealing data");
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 4, 0, "sealing data");
if (rc)
goto out;

@@ -561,8 +558,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
goto out;
}

- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 4, flags,
- "loading blob");
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 4, flags, "loading blob");
if (!rc)
*blob_handle = be32_to_cpup(
(__be32 *) &buf.data[TPM_HEADER_SIZE]);
@@ -612,8 +608,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
options->blobauth /* hmac */,
TPM_DIGEST_SIZE);

- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 6, flags,
- "unsealing");
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 6, flags, "unsealing");
if (rc > 0)
rc = -EPERM;

@@ -703,7 +698,7 @@ ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value,
tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
tpm_buf_append_u32(&buf, property_id);
tpm_buf_append_u32(&buf, 1);
- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL);
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0, NULL);
if (!rc) {
out = (struct tpm2_get_cap_out *)
&buf.data[TPM_HEADER_SIZE];
@@ -733,8 +728,7 @@ void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
if (rc)
return;
tpm_buf_append_u16(&buf, shutdown_type);
- tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
- "stopping the TPM");
+ tpm_transmit_cmd(chip, NULL, &buf, 0, 0, "stopping the TPM");
tpm_buf_destroy(&buf);
}

@@ -763,7 +757,7 @@ static int tpm2_do_selftest(struct tpm_chip *chip)
return rc;

tpm_buf_append_u8(&buf, full);
- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
"attempting the self test");
tpm_buf_destroy(&buf);

@@ -800,7 +794,7 @@ int tpm2_probe(struct tpm_chip *chip)
tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
tpm_buf_append_u32(&buf, 1);
- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL);
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0, NULL);
/* We ignore TPM return codes on purpose. */
if (rc >= 0) {
out = (struct tpm_output_header *)buf.data;
@@ -839,7 +833,7 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
tpm_buf_append_u32(&buf, 0);
tpm_buf_append_u32(&buf, 1);

- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 9, 0,
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 9, 0,
"get tpm pcr allocation");
if (rc)
goto out;
@@ -911,8 +905,7 @@ static int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
tpm_buf_append_u32(&buf, TPM2_CC_FIRST);
tpm_buf_append_u32(&buf, nr_commands);

- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
- 9 + 4 * nr_commands, 0, NULL);
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 9 + 4 * nr_commands, 0, NULL);
if (rc) {
tpm_buf_destroy(&buf);
goto out;
@@ -969,7 +962,7 @@ static int tpm2_startup(struct tpm_chip *chip)
return rc;

tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
- rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
"attempting to start the TPM");
tpm_buf_destroy(&buf);

diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index dcdfde3c253e..1131a8e7b79b 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -83,7 +83,7 @@ static int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
body_size = sizeof(*ctx) + be16_to_cpu(ctx->blob_size);
tpm_buf_append(&tbuf, &buf[*offset], body_size);

- rc = tpm_transmit_cmd(chip, NULL, tbuf.data, PAGE_SIZE, 4,
+ rc = tpm_transmit_cmd(chip, NULL, &tbuf, 4,
TPM_TRANSMIT_NESTED, NULL);
if (rc < 0) {
dev_warn(&chip->dev, "%s: failed with a system error %d\n",
@@ -132,7 +132,7 @@ static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,

tpm_buf_append_u32(&tbuf, handle);

- rc = tpm_transmit_cmd(chip, NULL, tbuf.data, PAGE_SIZE, 0,
+ rc = tpm_transmit_cmd(chip, NULL, &tbuf, 0,
TPM_TRANSMIT_NESTED, NULL);
if (rc < 0) {
dev_warn(&chip->dev, "%s: failed with a system error %d\n",
diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
index 87a0ce47f201..5f95fbfb7f6b 100644
--- a/drivers/char/tpm/tpm_vtpm_proxy.c
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -417,8 +417,7 @@ static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality)

proxy_dev->state |= STATE_DRIVER_COMMAND;

- rc = tpm_transmit_cmd(chip, NULL, buf.data, tpm_buf_length(&buf), 0,
- TPM_TRANSMIT_NESTED,
+ rc = tpm_transmit_cmd(chip, NULL, &buf, 0, TPM_TRANSMIT_NESTED,
"attempting to set locality");

proxy_dev->state &= ~STATE_DRIVER_COMMAND;
--
2.19.1