Commit bcfff838 authored by Roberto Sassu's avatar Roberto Sassu Committed by Jarkko Sakkinen
Browse files

tpm: dynamically allocate the allocated_banks array 



This patch renames active_banks (member of tpm_chip) to allocated_banks,
stores the number of allocated PCR banks in nr_allocated_banks (new member
of tpm_chip), and replaces the static array with a pointer to a dynamically
allocated array.

tpm2_get_pcr_allocation() determines if a PCR bank is allocated by checking
the mask in the TPML_PCR_SELECTION structure returned by the TPM for
TPM2_Get_Capability(). If a bank is not allocated, the TPM returns that
bank in TPML_PCR_SELECTION, with all bits in the mask set to zero. In this
case, the bank is not included in chip->allocated_banks, to avoid that TPM
driver users unnecessarily calculate a digest for that bank.

One PCR bank with algorithm set to SHA1 is always allocated for TPM 1.x.

As a consequence of the introduction of nr_allocated_banks,
tpm_pcr_extend() does not check anymore if the algorithm stored in tpm_chip
is equal to zero.

Signed-off-by: default avatarRoberto Sassu <roberto.sassu@huawei.com>
Tested-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
parent 47a6c28b

drivers/char/tpm/tpm-chip.c

+1 −0
Original line number Diff line number Diff line
@@ -266,6 +266,7 @@ static void tpm_dev_release(struct device *dev) 
	kfree(chip->log.bios_event_log);

	kfree(chip->work_space.context_buf);

	kfree(chip->work_space.session_buf);

	kfree(chip->allocated_banks);

	kfree(chip);

}

drivers/char/tpm/tpm-interface.c

+10 −8
Original line number Diff line number Diff line
@@ -318,8 +318,7 @@ EXPORT_SYMBOL_GPL(tpm_pcr_read); 
int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash)

{

	int rc;

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

	u32 count = 0;

	struct tpm2_digest *digest_list;

	int i;



	chip = tpm_find_get_ops(chip);
@@ -327,16 +326,19 @@ int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash) 
		return -ENODEV;



	if (chip->flags & TPM_CHIP_FLAG_TPM2) {

		memset(digest_list, 0, sizeof(digest_list));

		digest_list = kcalloc(chip->nr_allocated_banks,

				      sizeof(*digest_list), GFP_KERNEL);

		if (!digest_list)

			return -ENOMEM;



		for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&

			    chip->active_banks[i] != TPM2_ALG_ERROR; i++) {

			digest_list[i].alg_id = chip->active_banks[i];

		for (i = 0; i < chip->nr_allocated_banks; i++) {

			digest_list[i].alg_id = chip->allocated_banks[i];

			memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);

			count++;

		}



		rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list);

		rc = tpm2_pcr_extend(chip, pcr_idx, chip->nr_allocated_banks,

				     digest_list);

		kfree(digest_list);

		tpm_put_ops(chip);

		return rc;

	}

drivers/char/tpm/tpm.h

+2 −1
Original line number Diff line number Diff line
@@ -257,7 +257,8 @@ struct tpm_chip { 
	const struct attribute_group *groups[3];

	unsigned int groups_cnt;



	u16 active_banks[7];

	u32 nr_allocated_banks;

	u16 *allocated_banks;

#ifdef CONFIG_ACPI

	acpi_handle acpi_dev_handle;

	char ppi_version[TPM_PPI_VERSION_LEN + 1];

drivers/char/tpm/tpm1-cmd.c

+10 −0
Original line number Diff line number Diff line
@@ -696,6 +696,16 @@ int tpm1_auto_startup(struct tpm_chip *chip) 
		goto out;

	}



	chip->allocated_banks = kcalloc(1, sizeof(*chip->allocated_banks),

					GFP_KERNEL);

	if (!chip->allocated_banks) {

		rc = -ENOMEM;

		goto out;

	}



	chip->allocated_banks[0] = TPM2_ALG_SHA1;

	chip->nr_allocated_banks = 1;



	return rc;

out:

	if (rc > 0)

drivers/char/tpm/tpm2-cmd.c

+21 −10
Original line number Diff line number Diff line
@@ -234,7 +234,7 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count, 
	int i;

	int j;



	if (count > ARRAY_SIZE(chip->active_banks))

	if (count > chip->nr_allocated_banks)

		return -EINVAL;



	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
@@ -808,8 +808,10 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) 
	void *marker;

	void *end;

	void *pcr_select_offset;

	unsigned int count;

	u32 sizeof_pcr_selection;

	u32 nr_possible_banks;

	u32 nr_alloc_banks = 0;

	u16 hash_alg;

	u32 rsp_len;

	int rc;

	int i = 0;
@@ -826,11 +828,14 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) 
	if (rc)

		goto out;



	count = be32_to_cpup(

	nr_possible_banks = be32_to_cpup(

		(__be32 *)&buf.data[TPM_HEADER_SIZE + 5]);



	if (count > ARRAY_SIZE(chip->active_banks)) {

		rc = -ENODEV;

	chip->allocated_banks = kcalloc(nr_possible_banks,

					sizeof(*chip->allocated_banks),

					GFP_KERNEL);

	if (!chip->allocated_banks) {

		rc = -ENOMEM;

		goto out;

	}
@@ -839,7 +844,7 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) 
	rsp_len = be32_to_cpup((__be32 *)&buf.data[2]);

	end = &buf.data[rsp_len];



	for (i = 0; i < count; i++) {

	for (i = 0; i < nr_possible_banks; i++) {

		pcr_select_offset = marker +

			offsetof(struct tpm2_pcr_selection, size_of_select);

		if (pcr_select_offset >= end) {
@@ -848,17 +853,23 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) 
		}



		memcpy(&pcr_selection, marker, sizeof(pcr_selection));

		chip->active_banks[i] = be16_to_cpu(pcr_selection.hash_alg);

		hash_alg = be16_to_cpu(pcr_selection.hash_alg);



		pcr_select_offset = memchr_inv(pcr_selection.pcr_select, 0,

					       pcr_selection.size_of_select);

		if (pcr_select_offset) {

			chip->allocated_banks[nr_alloc_banks] = hash_alg;

			nr_alloc_banks++;

		}



		sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) +

			sizeof(pcr_selection.size_of_select) +

			pcr_selection.size_of_select;

		marker = marker + sizeof_pcr_selection;

	}



	chip->nr_allocated_banks = nr_alloc_banks;

out:

	if (i < ARRAY_SIZE(chip->active_banks))

		chip->active_banks[i] = TPM2_ALG_ERROR;



	tpm_buf_destroy(&buf);



	return rc;

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