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    Subject[PATCH v10, RESEND 1/6] tpm: dynamically allocate the allocated_banks array
    Date
    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: Roberto Sassu <roberto.sassu@huawei.com>
    Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
    Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
    ---
    drivers/char/tpm/tpm-chip.c | 1 +
    drivers/char/tpm/tpm-interface.c | 18 ++++++++++--------
    drivers/char/tpm/tpm.h | 3 ++-
    drivers/char/tpm/tpm1-cmd.c | 10 ++++++++++
    drivers/char/tpm/tpm2-cmd.c | 31 +++++++++++++++++++++----------
    5 files changed, 44 insertions(+), 19 deletions(-)

    diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
    index 2019635d0f70..9865776ee2cd 100644
    --- a/drivers/char/tpm/tpm-chip.c
    +++ b/drivers/char/tpm/tpm-chip.c
    @@ -265,6 +265,7 @@ 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);
    }

    diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
    index ce39fe043bcb..24f0eed531a0 100644
    --- a/drivers/char/tpm/tpm-interface.c
    +++ b/drivers/char/tpm/tpm-interface.c
    @@ -309,8 +309,7 @@ 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);
    @@ -318,16 +317,19 @@ 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;
    }
    diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
    index 183e2b93e0fe..cd330ace6248 100644
    --- a/drivers/char/tpm/tpm.h
    +++ b/drivers/char/tpm/tpm.h
    @@ -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];
    diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c
    index ec5f3693c096..e7d3228a0f37 100644
    --- a/drivers/char/tpm/tpm1-cmd.c
    +++ b/drivers/char/tpm/tpm1-cmd.c
    @@ -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)
    diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
    index 971d46efaca5..bd20b9a61fc0 100644
    --- a/drivers/char/tpm/tpm2-cmd.c
    +++ b/drivers/char/tpm/tpm2-cmd.c
    @@ -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;
    --
    2.17.1
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