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Commit aad887f6 authored by Jarkko Sakkinen's avatar Jarkko Sakkinen
Browse files

tpm: use struct tpm_chip for tpm_chip_find_get() 



Device number (the character device index) is not a stable identifier
for a TPM chip. That is the reason why every call site passes
TPM_ANY_NUM to tpm_chip_find_get().

This commit changes the API in a way that instead a struct tpm_chip
instance is given and NULL means the default chip. In addition, this
commit refines the documentation to be up to date with the
implementation.

Suggested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> (@chip_num -> @chip part)
Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@ziepe.ca>
Tested-by: default avatarPrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
parent 58cc1e4f

drivers/char/hw_random/tpm-rng.c

+1 −1
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ 


static int tpm_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)

{

	return tpm_get_random(TPM_ANY_NUM, data, max);

	return tpm_get_random(NULL, data, max);

}



static struct hwrng tpm_rng = {

drivers/char/tpm/tpm-chip.c

+14 −10
Original line number Diff line number Diff line
@@ -81,21 +81,26 @@ void tpm_put_ops(struct tpm_chip *chip) 
EXPORT_SYMBOL_GPL(tpm_put_ops);



/**

 * tpm_chip_find_get() - return tpm_chip for a given chip number

 * @chip_num: id to find

 * tpm_chip_find_get() - find and reserve a TPM chip

 * @chip:	a &struct tpm_chip instance, %NULL for the default chip

 *

 * The return'd chip has been tpm_try_get_ops'd and must be released via

 * tpm_put_ops

 * Finds a TPM chip and reserves its class device and operations. The chip must

 * be released with tpm_chip_put_ops() after use.

 *

 * Return:

 * A reserved &struct tpm_chip instance.

 * %NULL if a chip is not found.

 * %NULL if the chip is not available.

 */

struct tpm_chip *tpm_chip_find_get(int chip_num)

struct tpm_chip *tpm_chip_find_get(struct tpm_chip *chip)

{

	struct tpm_chip *chip, *res = NULL;

	struct tpm_chip *res = NULL;

	int chip_num = 0;

	int chip_prev;



	mutex_lock(&idr_lock);



	if (chip_num == TPM_ANY_NUM) {

		chip_num = 0;

	if (!chip) {

		do {

			chip_prev = chip_num;

			chip = idr_get_next(&dev_nums_idr, &chip_num);
@@ -105,8 +110,7 @@ struct tpm_chip *tpm_chip_find_get(int chip_num) 
			}

		} while (chip_prev != chip_num);

	} else {

		chip = idr_find(&dev_nums_idr, chip_num);

		if (chip && !tpm_try_get_ops(chip))

		if (!tpm_try_get_ops(chip))

			res = chip;

	}

drivers/char/tpm/tpm-interface.c

+71 −64
Original line number Diff line number Diff line
@@ -809,19 +809,20 @@ int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf) 
}



/**

 * tpm_is_tpm2 - is the chip a TPM2 chip?

 * @chip_num:	tpm idx # or ANY

 * tpm_is_tpm2 - do we a have a TPM2 chip?

 * @chip:	a &struct tpm_chip instance, %NULL for the default chip

 *

 * Returns < 0 on error, and 1 or 0 on success depending whether the chip

 * is a TPM2 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(u32 chip_num)

int tpm_is_tpm2(struct tpm_chip *chip)

{

	struct tpm_chip *chip;

	int rc;



	chip = tpm_chip_find_get(chip_num);

	if (chip == NULL)

	chip = tpm_chip_find_get(chip);

	if (!chip)

		return -ENODEV;



	rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
@@ -833,23 +834,19 @@ int tpm_is_tpm2(u32 chip_num) 
EXPORT_SYMBOL_GPL(tpm_is_tpm2);



/**

 * tpm_pcr_read - read a pcr value

 * @chip_num:	tpm idx # or ANY

 * @pcr_idx:	pcr idx to retrieve

 * @res_buf:	TPM_PCR value

 *		size of res_buf is 20 bytes (or NULL if you don't care)

 * 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

 *

 * The TPM driver should be built-in, but for whatever reason it

 * isn't, protect against the chip disappearing, by incrementing

 * the module usage count.

 * Return: same as with tpm_transmit_cmd()

 */

int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)

int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)

{

	struct tpm_chip *chip;

	int rc;



	chip = tpm_chip_find_get(chip_num);

	if (chip == NULL)

	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);
@@ -889,25 +886,26 @@ static int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash, 
}



/**

 * tpm_pcr_extend - extend pcr value with hash

 * @chip_num:	tpm idx # or AN&

 * @pcr_idx:	pcr idx to extend

 * @hash:	hash value used to extend pcr value

 * 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

 *

 * The TPM driver should be built-in, but for whatever reason it

 * isn't, protect against the chip disappearing, by incrementing

 * the module usage count.

 * 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(u32 chip_num, int pcr_idx, const u8 *hash)

int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)

{

	int rc;

	struct tpm_chip *chip;

	struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];

	u32 count = 0;

	int i;



	chip = tpm_chip_find_get(chip_num);

	if (chip == NULL)

	chip = tpm_chip_find_get(chip);

	if (!chip)

		return -ENODEV;



	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
@@ -1019,17 +1017,24 @@ int tpm1_auto_startup(struct tpm_chip *chip) 
	return rc;

}



int tpm_send(u32 chip_num, void *cmd, size_t buflen)

/**

 * 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)

{

	struct tpm_chip *chip;

	int rc;



	chip = tpm_chip_find_get(chip_num);

	if (chip == NULL)

	chip = tpm_chip_find_get(chip);

	if (!chip)

		return -ENODEV;



	rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, 0,

			      "attempting tpm_cmd");

			      "attempting to a send a command");

	tpm_put_ops(chip);

	return rc;

}
@@ -1127,16 +1132,15 @@ static const struct tpm_input_header tpm_getrandom_header = { 
};



/**

 * tpm_get_random() - Get random bytes from the tpm's RNG

 * @chip_num: A specific chip number for the request or TPM_ANY_NUM

 * 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

 *

 * Returns < 0 on error and the number of bytes read on success

 * Return: same as with tpm_transmit_cmd()

 */

int tpm_get_random(u32 chip_num, u8 *out, size_t max)

int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)

{

	struct tpm_chip *chip;

	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;
@@ -1145,8 +1149,8 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max) 
	if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)

		return -EINVAL;



	chip = tpm_chip_find_get(chip_num);

	if (chip == NULL)

	chip = tpm_chip_find_get(chip);

	if (!chip)

		return -ENODEV;



	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
@@ -1188,22 +1192,23 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max) 
EXPORT_SYMBOL_GPL(tpm_get_random);



/**

 * tpm_seal_trusted() - seal a trusted key

 * @chip_num: A specific chip number for the request or TPM_ANY_NUM

 * 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

 *

 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips

 * are supported.

 * 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(u32 chip_num, struct trusted_key_payload *payload,

int tpm_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload,

		     struct trusted_key_options *options)

{

	struct tpm_chip *chip;

	int rc;



	chip = tpm_chip_find_get(chip_num);

	if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))

	chip = tpm_chip_find_get(chip);

	if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))

		return -ENODEV;



	rc = tpm2_seal_trusted(chip, payload, options);
@@ -1215,21 +1220,23 @@ EXPORT_SYMBOL_GPL(tpm_seal_trusted); 


/**

 * tpm_unseal_trusted() - unseal a trusted key

 * @chip_num: A specific chip number for the request or TPM_ANY_NUM

 * @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

 *

 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips

 * are supported.

 * 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(u32 chip_num, struct trusted_key_payload *payload,

int tpm_unseal_trusted(struct tpm_chip *chip,

		       struct trusted_key_payload *payload,

		       struct trusted_key_options *options)

{

	struct tpm_chip *chip;

	int rc;



	chip = tpm_chip_find_get(chip_num);

	if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))

	chip = tpm_chip_find_get(chip);

	if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))

		return -ENODEV;



	rc = tpm2_unseal_trusted(chip, payload, options);

drivers/char/tpm/tpm.h

+1 −1
Original line number Diff line number Diff line
@@ -516,7 +516,7 @@ static inline void tpm_msleep(unsigned int delay_msec) 
		     delay_msec * 1000);

};



struct tpm_chip *tpm_chip_find_get(int chip_num);

struct tpm_chip *tpm_chip_find_get(struct tpm_chip *chip);

__must_check int tpm_try_get_ops(struct tpm_chip *chip);

void tpm_put_ops(struct tpm_chip *chip);

include/linux/tpm.h

+19 −19
Original line number Diff line number Diff line
@@ -24,11 +24,6 @@ 


#define TPM_DIGEST_SIZE 20	/* Max TPM v1.2 PCR size */



/*

 * Chip num is this value or a valid tpm idx

 */

#define	TPM_ANY_NUM 0xFFFF



struct tpm_chip;

struct trusted_key_payload;

struct trusted_key_options;
@@ -54,42 +49,47 @@ struct tpm_class_ops { 


#if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)



extern int tpm_is_tpm2(u32 chip_num);

extern int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf);

extern int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash);

extern int tpm_send(u32 chip_num, void *cmd, size_t buflen);

extern int tpm_get_random(u32 chip_num, u8 *data, size_t max);

extern int tpm_seal_trusted(u32 chip_num,

extern int tpm_is_tpm2(struct tpm_chip *chip);

extern int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf);

extern int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash);

extern int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen);

extern int tpm_get_random(struct tpm_chip *chip, u8 *data, size_t max);

extern int tpm_seal_trusted(struct tpm_chip *chip,

			    struct trusted_key_payload *payload,

			    struct trusted_key_options *options);

extern int tpm_unseal_trusted(u32 chip_num,

extern int tpm_unseal_trusted(struct tpm_chip *chip,

			      struct trusted_key_payload *payload,

			      struct trusted_key_options *options);

#else

static inline int tpm_is_tpm2(u32 chip_num)

static inline int tpm_is_tpm2(struct tpm_chip *chip)

{

	return -ENODEV;

}

static inline int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf) {

static inline int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)

{

	return -ENODEV;

}

static inline int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash) {

static inline int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx,

				 const u8 *hash)

{

	return -ENODEV;

}

static inline int tpm_send(u32 chip_num, void *cmd, size_t buflen) {

static inline int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)

{

	return -ENODEV;

}

static inline int tpm_get_random(u32 chip_num, u8 *data, size_t max) {

static inline int tpm_get_random(struct tpm_chip *chip, u8 *data, size_t max)

{

	return -ENODEV;

}



static inline int tpm_seal_trusted(u32 chip_num,

static inline int tpm_seal_trusted(struct tpm_chip *chip,

				   struct trusted_key_payload *payload,

				   struct trusted_key_options *options)

{

	return -ENODEV;

}

static inline int tpm_unseal_trusted(u32 chip_num,

static inline int tpm_unseal_trusted(struct tpm_chip *chip,

				     struct trusted_key_payload *payload,

				     struct trusted_key_options *options)

{