Re: [PATCH RFC v2 3/5] tpm: infrastructure for TPM spaces

From: Jarkko Sakkinen
Date: Thu Jan 12 2017 - 15:52:06 EST

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In reply to: Jarkko Sakkinen: "Re: [tpmdd-devel] [PATCH RFC v2 3/5] tpm: infrastructure for TPM spaces"
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On Thu, Jan 12, 2017 at 07:46:06PM +0200, Jarkko Sakkinen wrote:
> Added ability to tpm_transmit() to supply a TPM space that contains
> mapping from virtual handles to physical handles and backing storage for
> swapping transient objects. TPM space is isolated from other users of
> the TPM.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> ---
> drivers/char/tpm/Makefile | 2 +-
> drivers/char/tpm/tpm-chip.c | 7 +
> drivers/char/tpm/tpm-dev.c | 2 +-
> drivers/char/tpm/tpm-interface.c | 61 ++++----
> drivers/char/tpm/tpm-sysfs.c | 2 +-
> drivers/char/tpm/tpm.h | 22 ++-
> drivers/char/tpm/tpm2-cmd.c | 34 +++--
> drivers/char/tpm/tpm2-space.c | 298 +++++++++++++++++++++++++++++++++++++++
> 8 files changed, 382 insertions(+), 46 deletions(-)
> create mode 100644 drivers/char/tpm/tpm2-space.c
>
> diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
> index a05b1eb..251d0ed 100644
> --- a/drivers/char/tpm/Makefile
> +++ b/drivers/char/tpm/Makefile
> @@ -3,7 +3,7 @@
> #
> obj-$(CONFIG_TCG_TPM) += tpm.o
> tpm-y := tpm-interface.o tpm-dev.o tpm-sysfs.o tpm-chip.o tpm2-cmd.o \
> - tpm_eventlog.o
> + tpm_eventlog.o tpm2-space.o
> tpm-$(CONFIG_ACPI) += tpm_ppi.o tpm_acpi.o
> tpm-$(CONFIG_OF) += tpm_of.o
> obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index c406343..993b9ae 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -128,6 +128,7 @@ static void tpm_dev_release(struct device *dev)
> mutex_unlock(&idr_lock);
>
> kfree(chip->log.bios_event_log);
> + kfree(chip->work_space.context_buf);
> kfree(chip);
> }
>
> @@ -189,6 +190,12 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev,
> chip->cdev.owner = THIS_MODULE;
> chip->cdev.kobj.parent = &chip->dev.kobj;
>
> + chip->work_space.context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
> + if (!chip->work_space.context_buf) {
> + rc = -ENOMEM;
> + goto out;
> + }
> +
> return chip;
>
> out:
> diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c
> index 912ad30..249eeb0 100644
> --- a/drivers/char/tpm/tpm-dev.c
> +++ b/drivers/char/tpm/tpm-dev.c
> @@ -144,7 +144,7 @@ static ssize_t tpm_write(struct file *file, const char __user *buf,
> mutex_unlock(&priv->buffer_mutex);
> return -EPIPE;
> }
> - out_size = tpm_transmit(priv->chip, priv->data_buffer,
> + out_size = tpm_transmit(priv->chip, NULL, priv->data_buffer,
> sizeof(priv->data_buffer), 0);
>
> tpm_put_ops(priv->chip);
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index 0c5aba1..65fcd04c 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -370,10 +370,11 @@ static bool tpm_validate_command(struct tpm_chip *chip, const u8 *cmd,
> * 0 when the operation is successful.
> * A negative number for system errors (errno).
> */
> -ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
> - unsigned int flags)
> +ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
> + u8 *buf, size_t bufsiz, unsigned int flags)
> {
> - ssize_t rc;
> + int rc;
> + ssize_t len = 0;
> u32 count, ordinal;
> unsigned long stop;
>
> @@ -399,10 +400,14 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
> if (chip->dev.parent)
> pm_runtime_get_sync(chip->dev.parent);
>
> + rc = tpm2_prepare_space(chip, space, ordinal, buf, bufsiz);
> + if (rc)
> + goto out;
> +
> rc = chip->ops->send(chip, (u8 *) buf, count);
> if (rc < 0) {
> dev_err(&chip->dev,
> - "tpm_transmit: tpm_send: error %zd\n", rc);
> + "tpm_transmit: tpm_send: error %d\n", rc);
> goto out;
> }
>
> @@ -435,17 +440,23 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
> goto out;
>
> out_recv:
> - rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
> - if (rc < 0)
> + len = chip->ops->recv(chip, (u8 *) buf, bufsiz);
> + if (len < 0) {
> dev_err(&chip->dev,
> - "tpm_transmit: tpm_recv: error %zd\n", rc);
> + "tpm_transmit: tpm_recv: error %d\n", rc);
> + rc = len;
> + goto out;
> + }
> +
> + rc = tpm2_commit_space(chip, space, ordinal, buf, bufsiz);
> +
> out:
> if (chip->dev.parent)
> pm_runtime_put_sync(chip->dev.parent);
>
> if (!(flags & TPM_TRANSMIT_UNLOCKED))
> mutex_unlock(&chip->tpm_mutex);
> - return rc;
> + return rc ? rc : len;
> }
>
> /**
> @@ -463,13 +474,14 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
> * A negative number for system errors (errno).
> * A positive number for a TPM error.
> */
> -ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd,
> - int len, unsigned int flags, const char *desc)
> +ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
> + void *cmd, int len, unsigned int flags,
> + const char *desc)
> {
> const struct tpm_output_header *header;
> int err;
>
> - len = tpm_transmit(chip, (const u8 *)cmd, len, flags);
> + len = tpm_transmit(chip, space, cmd, len, flags);
> if (len < 0)
> return len;
> else if (len < TPM_HEADER_SIZE)
> @@ -521,7 +533,7 @@ ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
> tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> tpm_cmd.params.getcap_in.subcap = cpu_to_be32(subcap_id);
> }
> - rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
> + rc = tpm_transmit_cmd(chip, NULL, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
> desc);
> if (!rc)
> *cap = tpm_cmd.params.getcap_out.cap;
> @@ -545,8 +557,9 @@ static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
> start_cmd.header.in = tpm_startup_header;
>
> start_cmd.params.startup_in.startup_type = startup_type;
> - return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
> - "attempting to start the TPM");
> + return tpm_transmit_cmd(chip, NULL, &start_cmd,
> + TPM_INTERNAL_RESULT_SIZE,
> + 0, "attempting to start the TPM");
> }
>
> int tpm_get_timeouts(struct tpm_chip *chip)
> @@ -687,8 +700,8 @@ static int tpm_continue_selftest(struct tpm_chip *chip)
> struct tpm_cmd_t cmd;
>
> cmd.header.in = continue_selftest_header;
> - rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
> - "continue selftest");
> + rc = tpm_transmit_cmd(chip, NULL, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
> + 0, "continue selftest");
> return rc;
> }
>
> @@ -707,7 +720,7 @@ int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
>
> cmd.header.in = pcrread_header;
> cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
> - rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
> + rc = tpm_transmit_cmd(chip, NULL, &cmd, READ_PCR_RESULT_SIZE, 0,
> "attempting to read a pcr value");
>
> if (rc == 0)
> @@ -805,7 +818,7 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
> cmd.header.in = pcrextend_header;
> cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
> memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
> - rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
> + rc = tpm_transmit_cmd(chip, NULL, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
> "attempting extend a PCR value");
>
> tpm_put_ops(chip);
> @@ -909,7 +922,7 @@ int tpm_send(u32 chip_num, void *cmd, size_t buflen)
> if (chip == NULL)
> return -ENODEV;
>
> - rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
> + rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, "attempting tpm_cmd");
>
> tpm_put_ops(chip);
> return rc;
> @@ -1011,15 +1024,15 @@ int tpm_pm_suspend(struct device *dev)
> cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
> memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
> TPM_DIGEST_SIZE);
> - rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
> - "extending dummy pcr before suspend");
> + rc = tpm_transmit_cmd(chip, NULL, &cmd, EXTEND_PCR_RESULT_SIZE,
> + 0, "extending dummy pcr before suspend");
> }
>
> /* now do the actual savestate */
> for (try = 0; try < TPM_RETRY; try++) {
> cmd.header.in = savestate_header;
> - rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
> - NULL);
> + rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,
> + 0, NULL);
>
> /*
> * If the TPM indicates that it is too busy to respond to
> @@ -1102,7 +1115,7 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max)
> tpm_cmd.header.in = tpm_getrandom_header;
> tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
>
> - err = tpm_transmit_cmd(chip, &tpm_cmd,
> + err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
> TPM_GETRANDOM_RESULT_SIZE + num_bytes,
> 0, "attempting get random");
> if (err)
> diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
> index 848ad65..dd31a00 100644
> --- a/drivers/char/tpm/tpm-sysfs.c
> +++ b/drivers/char/tpm/tpm-sysfs.c
> @@ -39,7 +39,7 @@ static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
> struct tpm_chip *chip = to_tpm_chip(dev);
>
> tpm_cmd.header.in = tpm_readpubek_header;
> - err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE, 0,
> + err = tpm_transmit_cmd(chip, NULL, &tpm_cmd, READ_PUBEK_RESULT_SIZE, 0,
> "attempting to read the PUBEK");
> if (err)
> goto out;
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index c87c221..0e93b93 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -91,6 +91,7 @@ enum tpm2_structures {
>
> enum tpm2_return_codes {
> TPM2_RC_HASH = 0x0083, /* RC_FMT1 */
> + TPM2_RC_HANDLE = 0x008B,
> TPM2_RC_INITIALIZE = 0x0100, /* RC_VER1 */
> TPM2_RC_DISABLED = 0x0120,
> TPM2_RC_TESTING = 0x090A, /* RC_WARN */
> @@ -114,6 +115,8 @@ enum tpm2_command_codes {
> TPM2_CC_CREATE = 0x0153,
> TPM2_CC_LOAD = 0x0157,
> TPM2_CC_UNSEAL = 0x015E,
> + TPM2_CC_CONTEXT_LOAD = 0x0161,
> + TPM2_CC_CONTEXT_SAVE = 0x0162,
> TPM2_CC_FLUSH_CONTEXT = 0x0165,
> TPM2_CC_GET_CAPABILITY = 0x017A,
> TPM2_CC_GET_RANDOM = 0x017B,
> @@ -151,6 +154,11 @@ enum tpm2_cc_attrs {
>
> #define TPM_PPI_VERSION_LEN 3
>
> +struct tpm_space {
> + u32 context_tbl[14];
> + u8 *context_buf;
> +};

I'll add a cc whitelist here in the next version. I also
decrease the size of the context_tbl to three.

It could be something like

DECLARE_BITMAP(cc_map, TPM2_CC_LAST - TPM2_CC_FIRST + 1);

Or

u32 *cc_tbl;
unsigned int cc_tbl_cnt;

The first alternative takes less space and is quicker to look up.
The second alternative is more dynamic (in terms of range).

/Jarkko

Next message: Dave Gerlach: "[PATCH 1/3] misc: sram: Split sram data structures into local header"
Previous message: Kevin Hilman: "Re: [PATCH, REGRESSION] ubifs: fix unencrypted journal write"
In reply to: Jarkko Sakkinen: "Re: [tpmdd-devel] [PATCH RFC v2 3/5] tpm: infrastructure for TPM spaces"
Next in thread: James Bottomley: "Re: [tpmdd-devel] [PATCH RFC v2 3/5] tpm: infrastructure for TPM spaces"
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