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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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/char/hw_random/tpm-rng.c
View File

@ -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 = {

24
drivers/char/tpm/tpm-chip.c
View File

@ -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;
}

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);

2
drivers/char/tpm/tpm.h
View File

@ -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);

38
include/linux/tpm.h
View File

@ -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)
{

2
security/integrity/ima/ima_crypto.c
View File

@ -632,7 +632,7 @@ static void __init ima_pcrread(int idx, u8 *pcr)
if (!ima_used_chip)
return;
if (tpm_pcr_read(TPM_ANY_NUM, idx, pcr) != 0)
if (tpm_pcr_read(NULL, idx, pcr) != 0)
pr_err("Error Communicating to TPM chip\n");
}

2
security/integrity/ima/ima_init.c
View File

@ -110,7 +110,7 @@ int __init ima_init(void)
int rc;
ima_used_chip = 0;
rc = tpm_pcr_read(TPM_ANY_NUM, 0, pcr_i);
rc = tpm_pcr_read(NULL, 0, pcr_i);
if (rc == 0)
ima_used_chip = 1;

2
security/integrity/ima/ima_queue.c
View File

@ -145,7 +145,7 @@ static int ima_pcr_extend(const u8 *hash, int pcr)
if (!ima_used_chip)
return result;
result = tpm_pcr_extend(TPM_ANY_NUM, pcr, hash);
result = tpm_pcr_extend(NULL, pcr, hash);
if (result != 0)
pr_err("Error Communicating to TPM chip, result: %d\n", result);
return result;

35
security/keys/trusted.c
View File

@ -355,13 +355,12 @@ out:
* For key specific tpm requests, we will generate and send our
* own TPM command packets using the drivers send function.
*/
static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd,
size_t buflen)
static int trusted_tpm_send(unsigned char *cmd, size_t buflen)
{
int rc;
dump_tpm_buf(cmd);
rc = tpm_send(chip_num, cmd, buflen);
rc = tpm_send(NULL, cmd, buflen);
dump_tpm_buf(cmd);
if (rc > 0)
/* Can't return positive return codes values to keyctl */
@ -382,10 +381,10 @@ static int pcrlock(const int pcrnum)
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
ret = tpm_get_random(TPM_ANY_NUM, hash, SHA1_DIGEST_SIZE);
ret = tpm_get_random(NULL, hash, SHA1_DIGEST_SIZE);
if (ret != SHA1_DIGEST_SIZE)
return ret;
return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0;
return tpm_pcr_extend(NULL, pcrnum, hash) ? -EINVAL : 0;
}
/*
@ -398,7 +397,7 @@ static int osap(struct tpm_buf *tb, struct osapsess *s,
unsigned char ononce[TPM_NONCE_SIZE];
int ret;
ret = tpm_get_random(TPM_ANY_NUM, ononce, TPM_NONCE_SIZE);
ret = tpm_get_random(NULL, ononce, TPM_NONCE_SIZE);
if (ret != TPM_NONCE_SIZE)
return ret;
@ -410,7 +409,7 @@ static int osap(struct tpm_buf *tb, struct osapsess *s,
store32(tb, handle);
storebytes(tb, ononce, TPM_NONCE_SIZE);
ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
if (ret < 0)
return ret;
@ -434,7 +433,7 @@ static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
store16(tb, TPM_TAG_RQU_COMMAND);
store32(tb, TPM_OIAP_SIZE);
store32(tb, TPM_ORD_OIAP);
ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
if (ret < 0)
return ret;
@ -493,7 +492,7 @@ static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
if (ret < 0)
goto out;
ret = tpm_get_random(TPM_ANY_NUM, td->nonceodd, TPM_NONCE_SIZE);
ret = tpm_get_random(NULL, td->nonceodd, TPM_NONCE_SIZE);
if (ret != TPM_NONCE_SIZE)
goto out;
ordinal = htonl(TPM_ORD_SEAL);
@ -542,7 +541,7 @@ static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
store8(tb, cont);
storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
if (ret < 0)
goto out;
@ -603,7 +602,7 @@ static int tpm_unseal(struct tpm_buf *tb,
ordinal = htonl(TPM_ORD_UNSEAL);
keyhndl = htonl(SRKHANDLE);
ret = tpm_get_random(TPM_ANY_NUM, nonceodd, TPM_NONCE_SIZE);
ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
if (ret != TPM_NONCE_SIZE) {
pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
return ret;
@ -635,7 +634,7 @@ static int tpm_unseal(struct tpm_buf *tb,
store8(tb, cont);
storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
if (ret < 0) {
pr_info("trusted_key: authhmac failed (%d)\n", ret);
return ret;
@ -748,7 +747,7 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
int i;
int tpm2;
tpm2 = tpm_is_tpm2(TPM_ANY_NUM);
tpm2 = tpm_is_tpm2(NULL);
if (tpm2 < 0)
return tpm2;
@ -917,7 +916,7 @@ static struct trusted_key_options *trusted_options_alloc(void)
struct trusted_key_options *options;
int tpm2;
tpm2 = tpm_is_tpm2(TPM_ANY_NUM);
tpm2 = tpm_is_tpm2(NULL);
if (tpm2 < 0)
return NULL;
@ -967,7 +966,7 @@ static int trusted_instantiate(struct key *key,
size_t key_len;
int tpm2;
tpm2 = tpm_is_tpm2(TPM_ANY_NUM);
tpm2 = tpm_is_tpm2(NULL);
if (tpm2 < 0)
return tpm2;
@ -1008,7 +1007,7 @@ static int trusted_instantiate(struct key *key,
switch (key_cmd) {
case Opt_load:
if (tpm2)
ret = tpm_unseal_trusted(TPM_ANY_NUM, payload, options);
ret = tpm_unseal_trusted(NULL, payload, options);
else
ret = key_unseal(payload, options);
dump_payload(payload);
@ -1018,13 +1017,13 @@ static int trusted_instantiate(struct key *key,
break;
case Opt_new:
key_len = payload->key_len;
ret = tpm_get_random(TPM_ANY_NUM, payload->key, key_len);
ret = tpm_get_random(NULL, payload->key, key_len);
if (ret != key_len) {
pr_info("trusted_key: key_create failed (%d)\n", ret);
goto out;
}
if (tpm2)
ret = tpm_seal_trusted(TPM_ANY_NUM, payload, options);
ret = tpm_seal_trusted(NULL, payload, options);
else
ret = key_seal(payload, options);
if (ret < 0)