1 files changed, 106 insertions, 152 deletions

diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index d31b09099216..c31b490bd41d 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -27,46 +27,6 @@ enum tpm2_session_attributes {
 	TPM2_SA_CONTINUE_SESSION	= BIT(0),
 };
 
-struct tpm2_startup_in {
-	__be16	startup_type;
-} __packed;
-
-struct tpm2_get_tpm_pt_in {
-	__be32	cap_id;
-	__be32	property_id;
-	__be32	property_cnt;
-} __packed;
-
-struct tpm2_get_tpm_pt_out {
-	u8	more_data;
-	__be32	subcap_id;
-	__be32	property_cnt;
-	__be32	property_id;
-	__be32	value;
-} __packed;
-
-struct tpm2_get_random_in {
-	__be16	size;
-} __packed;
-
-struct tpm2_get_random_out {
-	__be16	size;
-	u8	buffer[TPM_MAX_RNG_DATA];
-} __packed;
-
-union tpm2_cmd_params {
-	struct	tpm2_startup_in		startup_in;
-	struct	tpm2_get_tpm_pt_in	get_tpm_pt_in;
-	struct	tpm2_get_tpm_pt_out	get_tpm_pt_out;
-	struct	tpm2_get_random_in	getrandom_in;
-	struct	tpm2_get_random_out	getrandom_out;
-};
-
-struct tpm2_cmd {
-	tpm_cmd_header		header;
-	union tpm2_cmd_params	params;
-} __packed;
-
 struct tpm2_hash {
 	unsigned int crypto_id;
 	unsigned int tpm_id;
@@ -321,82 +281,72 @@ int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
 }
 
 
-#define TPM2_GETRANDOM_IN_SIZE \
-	(sizeof(struct tpm_input_header) + \
-	 sizeof(struct tpm2_get_random_in))
-
-static const struct tpm_input_header tpm2_getrandom_header = {
-	.tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
-	.length = cpu_to_be32(TPM2_GETRANDOM_IN_SIZE),
-	.ordinal = cpu_to_be32(TPM2_CC_GET_RANDOM)
-};
+struct tpm2_get_random_out {
+	__be16 size;
+	u8 buffer[TPM_MAX_RNG_DATA];
+} __packed;
 
 /**
  * tpm2_get_random() - get random bytes from the TPM RNG
  *
- * @chip: TPM chip to use
- * @out: destination buffer for the random bytes
- * @max: the max number of bytes to write to @out
+ * @chip:	a &tpm_chip instance
+ * @dest:	destination buffer
+ * @max:	the max number of random bytes to pull
  *
  * Return:
- *    Size of the output buffer, or -EIO on error.
+ *   size of the buffer on success,
+ *   -errno otherwise
  */
-int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
+int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
 {
-	struct tpm2_cmd cmd;
-	u32 recd, rlength;
-	u32 num_bytes;
+	struct tpm2_get_random_out *out;
+	struct tpm_buf buf;
+	u32 recd;
+	u32 num_bytes = max;
 	int err;
 	int total = 0;
 	int retries = 5;
-	u8 *dest = out;
+	u8 *dest_ptr = dest;
 
-	num_bytes = min_t(u32, max, sizeof(cmd.params.getrandom_out.buffer));
-
-	if (!out || !num_bytes ||
-	    max > sizeof(cmd.params.getrandom_out.buffer))
+	if (!num_bytes || max > TPM_MAX_RNG_DATA)
 		return -EINVAL;
 
-	do {
-		cmd.header.in = tpm2_getrandom_header;
-		cmd.params.getrandom_in.size = cpu_to_be16(num_bytes);
+	err = tpm_buf_init(&buf, 0, 0);
+	if (err)
+		return err;
 
-		err = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd),
+	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,
 				       offsetof(struct tpm2_get_random_out,
 						buffer),
 				       0, "attempting get random");
 		if (err)
-			break;
+			goto out;
 
-		recd = min_t(u32, be16_to_cpu(cmd.params.getrandom_out.size),
-			     num_bytes);
-		rlength = be32_to_cpu(cmd.header.out.length);
-		if (rlength < offsetof(struct tpm2_get_random_out, buffer) +
-			      recd)
-			return -EFAULT;
-		memcpy(dest, cmd.params.getrandom_out.buffer, recd);
+		out = (struct tpm2_get_random_out *)
+			&buf.data[TPM_HEADER_SIZE];
+		recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
+		if (tpm_buf_length(&buf) <
+		    offsetof(struct tpm2_get_random_out, buffer) + recd) {
+			err = -EFAULT;
+			goto out;
+		}
+		memcpy(dest_ptr, out->buffer, recd);
 
-		dest += recd;
+		dest_ptr += recd;
 		total += recd;
 		num_bytes -= recd;
 	} while (retries-- && total < max);
 
+	tpm_buf_destroy(&buf);
 	return total ? total : -EIO;
+out:
+	tpm_buf_destroy(&buf);
+	return err;
 }
 
-#define TPM2_GET_TPM_PT_IN_SIZE \
-	(sizeof(struct tpm_input_header) + \
-	 sizeof(struct tpm2_get_tpm_pt_in))
-
-#define TPM2_GET_TPM_PT_OUT_BODY_SIZE \
-	 sizeof(struct tpm2_get_tpm_pt_out)
-
-static const struct tpm_input_header tpm2_get_tpm_pt_header = {
-	.tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
-	.length = cpu_to_be32(TPM2_GET_TPM_PT_IN_SIZE),
-	.ordinal = cpu_to_be32(TPM2_CC_GET_CAPABILITY)
-};
-
 /**
  * tpm2_flush_context_cmd() - execute a TPM2_FlushContext command
  * @chip: TPM chip to use
@@ -471,7 +421,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
 {
 	unsigned int blob_len;
 	struct tpm_buf buf;
-	u32 hash, rlength;
+	u32 hash;
 	int i;
 	int rc;
 
@@ -546,8 +496,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
 		rc = -E2BIG;
 		goto out;
 	}
-	rlength = be32_to_cpu(((struct tpm2_cmd *)&buf)->header.out.length);
-	if (rlength < TPM_HEADER_SIZE + 4 + blob_len) {
+	if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) {
 		rc = -EFAULT;
 		goto out;
 	}
@@ -657,7 +606,6 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
 	u16 data_len;
 	u8 *data;
 	int rc;
-	u32 rlength;
 
 	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
 	if (rc)
@@ -685,9 +633,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
 			goto out;
 		}
 
-		rlength = be32_to_cpu(((struct tpm2_cmd *)&buf)
-					->header.out.length);
-		if (rlength < TPM_HEADER_SIZE + 6 + data_len) {
+		if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) {
 			rc = -EFAULT;
 			goto out;
 		}
@@ -733,69 +679,71 @@ out:
 	return rc;
 }
 
+struct tpm2_get_cap_out {
+	u8 more_data;
+	__be32 subcap_id;
+	__be32 property_cnt;
+	__be32 property_id;
+	__be32 value;
+} __packed;
+
 /**
  * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
- * @chip:		TPM chip to use.
+ * @chip:		a &tpm_chip instance
  * @property_id:	property ID.
  * @value:		output variable.
  * @desc:		passed to tpm_transmit_cmd()
  *
- * Return: Same as with tpm_transmit_cmd.
+ * Return:
+ *   0 on success,
+ *   -errno or a TPM return code otherwise
  */
 ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,  u32 *value,
 			const char *desc)
 {
-	struct tpm2_cmd cmd;
+	struct tpm2_get_cap_out *out;
+	struct tpm_buf buf;
 	int rc;
 
-	cmd.header.in = tpm2_get_tpm_pt_header;
-	cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
-	cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(property_id);
-	cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
-
-	rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd),
-			      TPM2_GET_TPM_PT_OUT_BODY_SIZE, 0, desc);
-	if (!rc)
-		*value = be32_to_cpu(cmd.params.get_tpm_pt_out.value);
-
+	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
+	if (rc)
+		return rc;
+	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);
+	if (!rc) {
+		out = (struct tpm2_get_cap_out *)
+			&buf.data[TPM_HEADER_SIZE];
+		*value = be32_to_cpu(out->value);
+	}
+	tpm_buf_destroy(&buf);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
 
-#define TPM2_SHUTDOWN_IN_SIZE \
-	(sizeof(struct tpm_input_header) + \
-	 sizeof(struct tpm2_startup_in))
-
-static const struct tpm_input_header tpm2_shutdown_header = {
-	.tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
-	.length = cpu_to_be32(TPM2_SHUTDOWN_IN_SIZE),
-	.ordinal = cpu_to_be32(TPM2_CC_SHUTDOWN)
-};
-
 /**
- * tpm2_shutdown() - send shutdown command to the TPM chip
+ * tpm2_shutdown() - send a TPM shutdown command
+ *
+ * Sends a TPM shutdown command. The shutdown command is used in call
+ * sites where the system is going down. If it fails, there is not much
+ * that can be done except print an error message.
  *
- * @chip:		TPM chip to use.
- * @shutdown_type:	shutdown type. The value is either
- *			TPM_SU_CLEAR or TPM_SU_STATE.
+ * @chip:		a &tpm_chip instance
+ * @shutdown_type:	TPM_SU_CLEAR or TPM_SU_STATE.
  */
 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
 {
-	struct tpm2_cmd cmd;
+	struct tpm_buf buf;
 	int rc;
 
-	cmd.header.in = tpm2_shutdown_header;
-	cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type);
-
-	rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0, 0,
-			      "stopping the TPM");
-
-	/* In places where shutdown command is sent there's no much we can do
-	 * except print the error code on a system failure.
-	 */
-	if (rc < 0 && rc != -EPIPE)
-		dev_warn(&chip->dev, "transmit returned %d while stopping the TPM",
-			 rc);
+	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
+	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_buf_destroy(&buf);
 }
 
 /*
@@ -863,31 +811,37 @@ static int tpm2_do_selftest(struct tpm_chip *chip)
 }
 
 /**
- * tpm2_probe() - probe TPM 2.0
- * @chip: TPM chip to use
+ * tpm2_probe() - probe for the TPM 2.0 protocol
+ * @chip:	a &tpm_chip instance
  *
- * Return: < 0 error and 0 on success.
+ * Send an idempotent TPM 2.0 command and see whether there is TPM2 chip in the
+ * other end based on the response tag. The flag TPM_CHIP_FLAG_TPM2 is set by
+ * this function if this is the case.
  *
- * Send idempotent TPM 2.0 command and see whether TPM 2.0 chip replied based on
- * the reply tag.
+ * Return:
+ *   0 on success,
+ *   -errno otherwise
  */
 int tpm2_probe(struct tpm_chip *chip)
 {
-	struct tpm2_cmd cmd;
+	struct tpm_output_header *out;
+	struct tpm_buf buf;
 	int rc;
 
-	cmd.header.in = tpm2_get_tpm_pt_header;
-	cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
-	cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100);
-	cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
-
-	rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0, 0, NULL);
-	if (rc <  0)
+	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
+	if (rc)
 		return rc;
-
-	if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS)
-		chip->flags |= TPM_CHIP_FLAG_TPM2;
-
+	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);
+	/* We ignore TPM return codes on purpose. */
+	if (rc >=  0) {
+		out = (struct tpm_output_header *)buf.data;
+		if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS)
+			chip->flags |= TPM_CHIP_FLAG_TPM2;
+	}
+	tpm_buf_destroy(&buf);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(tpm2_probe);