Re: [PATCH v5 12/17] tpm: remove @space from tpm_transmit()

Stefan Berger <stefanb@xxxxxxxxxxxxx> · Thu, 8 Nov 2018 10:18:34 -0500

On 11/8/18 9:15 AM, Jarkko Sakkinen wrote:
Remove @space from tpm_transmit() API` in order to completely remove the
bound between low-level transmission functionality and TPM spaces. The
only real dependency existing is the amount of data saved before trying
to send a command to the TPM.

It doesn't really matter if we save always a bit more than needed so
this commit changes the amount saved always to be the size of the TPM
header and three handles.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>


Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>


---
  drivers/char/tpm/tpm-dev-common.c |  2 +-
  drivers/char/tpm/tpm-interface.c  | 25 ++++++++++---------------
  drivers/char/tpm/tpm-sysfs.c      |  5 ++---
  drivers/char/tpm/tpm.h            | 10 +++++-----
  drivers/char/tpm/tpm1-cmd.c       | 16 +++++++---------
  drivers/char/tpm/tpm2-cmd.c       | 30 ++++++++++++++----------------
  drivers/char/tpm/tpm2-space.c     |  6 ++----
  drivers/char/tpm/tpm_vtpm_proxy.c |  2 +-
  8 files changed, 42 insertions(+), 54 deletions(-)

diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c
index 40c1cb09ebd2..c7dc54930576 100644
--- a/drivers/char/tpm/tpm-dev-common.c
+++ b/drivers/char/tpm/tpm-dev-common.c
@@ -48,7 +48,7 @@ static ssize_t tpm_dev_transmit(struct tpm_chip *chip, struct tpm_space *space,
  	if (ret)
  		goto out_lock;

-	len = tpm_transmit(chip, space, buf, bufsiz, TPM_TRANSMIT_UNLOCKED);
+	len = tpm_transmit(chip, buf, bufsiz, TPM_TRANSMIT_UNLOCKED);
  	if (len < 0)
  		ret = len;

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 7bec03e46043..8d75c103f280 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -120,9 +120,7 @@ static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
  	return chip->ops->go_idle(chip);
  }

-static ssize_t tpm_try_transmit(struct tpm_chip *chip,
-				struct tpm_space *space,
-				u8 *buf, size_t bufsiz,
+static ssize_t tpm_try_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
  				unsigned int flags)
  {
  	struct tpm_header *header = (void *)buf;
@@ -192,7 +190,6 @@ 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
@@ -208,8 +205,8 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
   * * 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)
+ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+		     unsigned int flags)
  {
  	struct tpm_header *header = (struct tpm_header *)buf;
  	/* space for header and handles */
@@ -218,8 +215,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
  	bool has_locality = false;
  	u32 rc = 0;
  	ssize_t ret;
-	const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE,
-				     bufsiz);
+	const size_t save_size = min(sizeof(save), bufsiz);
  	/* the command code is where the return code will be */
  	u32 cc = be32_to_cpu(header->return_code);

@@ -249,7 +245,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
  		if (ret)
  			goto out_locality;

-		ret = tpm_try_transmit(chip, space, buf, bufsiz, flags);
+		ret = tpm_try_transmit(chip, buf, bufsiz, flags);

  		/* This may fail but do not override ret. */
  		tpm_go_idle(chip, flags);
@@ -295,7 +291,6 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
  /**
   * tpm_transmit_cmd - send a tpm command to the device
   * @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
@@ -306,15 +301,15 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
   * * -errno	- A system error
   * * TPM_RC	- A TPM error
   */
-ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
-			 struct tpm_buf *buf, size_t min_rsp_body_length,
-			 unsigned int flags, const char *desc)
+ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf,
+			 size_t min_rsp_body_length, unsigned int flags,
+			 const char *desc)
  {
  	const struct tpm_header *header = (struct tpm_header *)buf->data;
  	int err;
  	ssize_t len;

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

@@ -463,7 +458,7 @@ int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
  		goto out;

  	memcpy(buf.data, cmd, buflen);
-	rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
+	rc = tpm_transmit_cmd(chip, &buf, 0, 0,
  			      "attempting to a send a command");
  	tpm_buf_destroy(&buf);
  out:
diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index 928d4e839bb7..03e704f99ed6 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -52,9 +52,8 @@ 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,
-			      READ_PUBEK_RESULT_MIN_BODY_SIZE, 0,
-			      "attempting to read the PUBEK");
+	rc = tpm_transmit_cmd(chip, &tpm_buf, READ_PUBEK_RESULT_MIN_BODY_SIZE,
+			      0, "attempting to read the PUBEK");
  	if (rc) {
  		tpm_buf_destroy(&tpm_buf);
  		return 0;
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 68d78ebba032..10a5bcf806aa 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -498,11 +498,11 @@ enum tpm_transmit_flags {
  	TPM_TRANSMIT_NESTED      = BIT(1),
  };

-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,
-			 struct tpm_buf *buf, size_t min_rsp_body_length,
-			 unsigned int flags, const char *desc);
+ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+		     unsigned int flags);
+ssize_t tpm_transmit_cmd(struct tpm_chip *chip, 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 f19b7c1ff800..162c255dd131 100644
--- a/drivers/char/tpm/tpm1-cmd.c
+++ b/drivers/char/tpm/tpm1-cmd.c
@@ -334,8 +334,7 @@ static int tpm1_startup(struct tpm_chip *chip)

  	tpm_buf_append_u16(&buf, TPM_ST_CLEAR);

-	rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
-			      "attempting to start the TPM");
+	rc = tpm_transmit_cmd(chip, &buf, 0, 0, "attempting to start the TPM");
  	tpm_buf_destroy(&buf);
  	return rc;
  }
@@ -460,7 +459,7 @@ 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, TPM_DIGEST_SIZE, 0, log_msg);
+	rc = tpm_transmit_cmd(chip, &buf, TPM_DIGEST_SIZE, 0, log_msg);
  	tpm_buf_destroy(&buf);
  	return rc;
  }
@@ -490,7 +489,7 @@ 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, min_cap_length, 0, desc);
+	rc = tpm_transmit_cmd(chip, &buf, min_cap_length, 0, desc);
  	if (!rc)
  		*cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
  	tpm_buf_destroy(&buf);
@@ -531,8 +530,7 @@ 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,
-				      sizeof(out->rng_data_len), 0,
+		rc = tpm_transmit_cmd(chip, &buf, sizeof(out->rng_data_len), 0,
  				      "attempting get random");
  		if (rc)
  			goto out;
@@ -577,7 +575,7 @@ 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, TPM_DIGEST_SIZE, 0,
+	rc = tpm_transmit_cmd(chip, &buf, TPM_DIGEST_SIZE, 0,
  			      "attempting to read a pcr value");
  	if (rc)
  		goto out;
@@ -611,7 +609,7 @@ static int tpm1_continue_selftest(struct tpm_chip *chip)
  	if (rc)
  		return rc;

-	rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0, "continue selftest");
+	rc = tpm_transmit_cmd(chip, &buf, 0, 0, "continue selftest");
  	tpm_buf_destroy(&buf);
  	return rc;
  }
@@ -737,7 +735,7 @@ 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, 0, 0, NULL);
+		rc = tpm_transmit_cmd(chip, &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 ab03f8600f89..f2b0e5c52a57 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -197,7 +197,7 @@ 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, 0, 0, res_buf ?
+	rc = tpm_transmit_cmd(chip, &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];
@@ -264,7 +264,7 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count,
  		}
  	}

-	rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
+	rc = tpm_transmit_cmd(chip, &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,
+		err = tpm_transmit_cmd(chip, &buf,
  				       offsetof(struct tpm2_get_random_out,
  						buffer),
  				       0, "attempting get random");
@@ -362,7 +362,7 @@ void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle,

  	tpm_buf_append_u32(&buf, handle);

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

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

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

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

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

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

@@ -698,7 +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, 0, 0, NULL);
+	rc = tpm_transmit_cmd(chip, &buf, 0, 0, NULL);
  	if (!rc) {
  		out = (struct tpm2_get_cap_out *)
  			&buf.data[TPM_HEADER_SIZE];
@@ -728,7 +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, 0, 0, "stopping the TPM");
+	tpm_transmit_cmd(chip, &buf, 0, 0, "stopping the TPM");
  	tpm_buf_destroy(&buf);
  }

@@ -757,7 +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, 0, 0,
+		rc = tpm_transmit_cmd(chip, &buf, 0, 0,
  				      "attempting the self test");
  		tpm_buf_destroy(&buf);

@@ -794,7 +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, 0, 0, NULL);
+	rc = tpm_transmit_cmd(chip, &buf, 0, 0, NULL);
  	/* We ignore TPM return codes on purpose. */
  	if (rc >=  0) {
  		out = (struct tpm_header *)buf.data;
@@ -833,8 +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, 9, 0,
-			      "get tpm pcr allocation");
+	rc = tpm_transmit_cmd(chip, &buf, 9, 0, "get tpm pcr allocation");
  	if (rc)
  		goto out;

@@ -905,7 +904,7 @@ 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, 9 + 4 * nr_commands, 0, NULL);
+	rc = tpm_transmit_cmd(chip, &buf, 9 + 4 * nr_commands, 0, NULL);
  	if (rc) {
  		tpm_buf_destroy(&buf);
  		goto out;
@@ -962,8 +961,7 @@ 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, 0, 0,
-			      "attempting to start the TPM");
+	rc = tpm_transmit_cmd(chip, &buf, 0, 0, "attempting to start the TPM");
  	tpm_buf_destroy(&buf);

  	return rc;
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index 9c009db15f88..d1c371db1ab7 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -83,8 +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, 4,
-			      TPM_TRANSMIT_UNLOCKED, NULL);
+	rc = tpm_transmit_cmd(chip, &tbuf, 4, TPM_TRANSMIT_UNLOCKED, NULL);
  	if (rc < 0) {
  		dev_warn(&chip->dev, "%s: failed with a system error %d\n",
  			 __func__, rc);
@@ -132,8 +131,7 @@ 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, 0,
-			      TPM_TRANSMIT_UNLOCKED, NULL);
+	rc = tpm_transmit_cmd(chip, &tbuf, 0, TPM_TRANSMIT_UNLOCKED, NULL);
  	if (rc < 0) {
  		dev_warn(&chip->dev, "%s: failed with a system error %d\n",
  			 __func__, rc);
diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
index 28eb5ab15b99..e8a1da2810a9 100644
--- a/drivers/char/tpm/tpm_vtpm_proxy.c
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -417,7 +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, 0, TPM_TRANSMIT_NESTED,
+	rc = tpm_transmit_cmd(chip, &buf, 0, TPM_TRANSMIT_NESTED,
  			      "attempting to set locality");

  	proxy_dev->state &= ~STATE_DRIVER_COMMAND;








