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Subject[PATCH] tpm: replace TPM_TRANSMIT_RAW with TPM_TRANSMIT_NESTED
Date
As TPM_TRANSMIT_RAW always requires also not to take locks for obvious
reasons (deadlock), this commit renames the flag as TPM_TRANSMIT_NESTED
and prevents taking tpm_mutex when the flag is given to tpm_transmit().

Suggested-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
drivers/char/tpm/tpm-interface.c | 13 ++++++-------
drivers/char/tpm/tpm.h | 14 +++++++-------
drivers/char/tpm/tpm2-space.c | 16 ++++++----------
drivers/char/tpm/tpm_vtpm_proxy.c | 2 +-
4 files changed, 20 insertions(+), 25 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index ad761e629a0f..1a803b0cf980 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -372,7 +372,7 @@ static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
{
int rc;

- if (flags & TPM_TRANSMIT_RAW)
+ if (flags & TPM_TRANSMIT_NESTED)
return 0;

if (!chip->ops->request_locality)
@@ -391,7 +391,7 @@ static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)
{
int rc;

- if (flags & TPM_TRANSMIT_RAW)
+ if (flags & TPM_TRANSMIT_NESTED)
return;

if (!chip->ops->relinquish_locality)
@@ -406,7 +406,7 @@ static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)

static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
{
- if (flags & TPM_TRANSMIT_RAW)
+ if (flags & TPM_TRANSMIT_NESTED)
return 0;

if (!chip->ops->cmd_ready)
@@ -417,7 +417,7 @@ static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)

static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
{
- if (flags & TPM_TRANSMIT_RAW)
+ if (flags & TPM_TRANSMIT_NESTED)
return 0;

if (!chip->ops->go_idle)
@@ -466,10 +466,9 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
return -E2BIG;
}

- if (!(flags & TPM_TRANSMIT_UNLOCKED))
+ if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
mutex_lock(&chip->tpm_mutex);

-
if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, true);

@@ -559,7 +558,7 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, false);

- if (!(flags & TPM_TRANSMIT_UNLOCKED))
+ if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
mutex_unlock(&chip->tpm_mutex);
return rc ? rc : len;
}
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index ba01488cd029..f3501d05264f 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -513,16 +513,16 @@ extern const struct file_operations tpmrm_fops;
extern struct idr dev_nums_idr;

/**
- * enum tpm_transmit_flags
+ * enum tpm_transmit_flags - flags for tpm_transmit()
*
- * @TPM_TRANSMIT_UNLOCKED: used to lock sequence of tpm_transmit calls.
- * @TPM_TRANSMIT_RAW: prevent recursive calls into setup steps
- * (go idle, locality,..). Always use with UNLOCKED
- * as it will fail on double locking.
+ * @TPM_TRANSMIT_UNLOCKED: do not lock the chip
+ * @TPM_TRANSMIT_NESTED: discard setup steps (power management,
+ * locality) including locking (i.e. implicit
+ * UNLOCKED)
*/
enum tpm_transmit_flags {
- TPM_TRANSMIT_UNLOCKED = BIT(0),
- TPM_TRANSMIT_RAW = BIT(1),
+ TPM_TRANSMIT_UNLOCKED = BIT(0),
+ TPM_TRANSMIT_NESTED = BIT(1),
};

ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index 11c85ed8c113..d2e101b32482 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -39,8 +39,7 @@ static void tpm2_flush_sessions(struct tpm_chip *chip, struct tpm_space *space)
for (i = 0; i < ARRAY_SIZE(space->session_tbl); i++) {
if (space->session_tbl[i])
tpm2_flush_context_cmd(chip, space->session_tbl[i],
- TPM_TRANSMIT_UNLOCKED |
- TPM_TRANSMIT_RAW);
+ TPM_TRANSMIT_NESTED);
}
}

@@ -85,7 +84,7 @@ static int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
tpm_buf_append(&tbuf, &buf[*offset], body_size);

rc = tpm_transmit_cmd(chip, NULL, tbuf.data, PAGE_SIZE, 4,
- TPM_TRANSMIT_UNLOCKED | TPM_TRANSMIT_RAW, NULL);
+ TPM_TRANSMIT_NESTED, NULL);
if (rc < 0) {
dev_warn(&chip->dev, "%s: failed with a system error %d\n",
__func__, rc);
@@ -134,7 +133,7 @@ static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
tpm_buf_append_u32(&tbuf, handle);

rc = tpm_transmit_cmd(chip, NULL, tbuf.data, PAGE_SIZE, 0,
- TPM_TRANSMIT_UNLOCKED | TPM_TRANSMIT_RAW, NULL);
+ TPM_TRANSMIT_NESTED, NULL);
if (rc < 0) {
dev_warn(&chip->dev, "%s: failed with a system error %d\n",
__func__, rc);
@@ -171,8 +170,7 @@ static void tpm2_flush_space(struct tpm_chip *chip)
for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++)
if (space->context_tbl[i] && ~space->context_tbl[i])
tpm2_flush_context_cmd(chip, space->context_tbl[i],
- TPM_TRANSMIT_UNLOCKED |
- TPM_TRANSMIT_RAW);
+ TPM_TRANSMIT_NESTED);

tpm2_flush_sessions(chip, space);
}
@@ -379,8 +377,7 @@ static int tpm2_map_response_header(struct tpm_chip *chip, u32 cc, u8 *rsp,

return 0;
out_no_slots:
- tpm2_flush_context_cmd(chip, phandle,
- TPM_TRANSMIT_UNLOCKED | TPM_TRANSMIT_RAW);
+ tpm2_flush_context_cmd(chip, phandle, TPM_TRANSMIT_NESTED);
dev_warn(&chip->dev, "%s: out of slots for 0x%08X\n", __func__,
phandle);
return -ENOMEM;
@@ -468,8 +465,7 @@ static int tpm2_save_space(struct tpm_chip *chip)
return rc;

tpm2_flush_context_cmd(chip, space->context_tbl[i],
- TPM_TRANSMIT_UNLOCKED |
- TPM_TRANSMIT_RAW);
+ TPM_TRANSMIT_NESTED);
space->context_tbl[i] = ~0;
}

diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
index e4f79f920450..87a0ce47f201 100644
--- a/drivers/char/tpm/tpm_vtpm_proxy.c
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -418,7 +418,7 @@ static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality)
proxy_dev->state |= STATE_DRIVER_COMMAND;

rc = tpm_transmit_cmd(chip, NULL, buf.data, tpm_buf_length(&buf), 0,
- TPM_TRANSMIT_UNLOCKED | TPM_TRANSMIT_RAW,
+ TPM_TRANSMIT_NESTED,
"attempting to set locality");

proxy_dev->state &= ~STATE_DRIVER_COMMAND;
--
2.17.0
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