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tpm: use struct tpm_chip for tpm_chip_find_get()

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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: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@ziepe.ca>
Tested-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
This commit is contained in:
Jarkko Sakkinen
2017-11-05 13:16:26 +02:00
parent 58cc1e4faf
commit aad887f664
9 changed files with 126 additions and 116 deletions
Download Patch File Download Diff File Expand all files Collapse all files

135
drivers/char/tpm/tpm-interface.c
View File

@@ -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 @@ out:
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
* @out: destination buffer for the random bytes
* @max: the max number of bytes to write to @out
* 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
* @options: authentication values and other options
* @payload: the key data in clear and encrypted form
* 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
* @options: authentication values and other options
* @payload: the key data in clear and encrypted form
* @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);