Re: [PATCH v7 14/17] tpm: remove TPM_TRANSMIT_UNLOCKED flag

From: Stefan Berger
Date: Tue Nov 13 2018 - 15:39:56 EST


On 11/13/18 1:36 PM, Jarkko Sakkinen wrote:
Added locking as part of tpm_try_get_ops() and tpm_put_ops() as they are
anyway used in most of the call sites except in tpmrm_release() where we
take the locks manually.
Ok, so this is pulling the locking further up.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>

Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>


---
drivers/char/tpm/tpm-chip.c | 2 ++
drivers/char/tpm/tpm-dev-common.c | 4 +---
drivers/char/tpm/tpm-interface.c | 8 --------
drivers/char/tpm/tpm.h | 8 ++------
drivers/char/tpm/tpm2-cmd.c | 13 ++++---------
drivers/char/tpm/tpm2-space.c | 15 ++++++---------
6 files changed, 15 insertions(+), 35 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 32db84683c40..157505b0f755 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -58,6 +58,7 @@ int tpm_try_get_ops(struct tpm_chip *chip)
if (!chip->ops)
goto out_lock;

+ mutex_lock(&chip->tpm_mutex);
return 0;
out_lock:
up_read(&chip->ops_sem);
@@ -75,6 +76,7 @@ EXPORT_SYMBOL_GPL(tpm_try_get_ops);
*/
void tpm_put_ops(struct tpm_chip *chip)
{
+ mutex_unlock(&chip->tpm_mutex);
up_read(&chip->ops_sem);
put_device(&chip->dev);
}
diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c
index c7dc54930576..582caefcf19b 100644
--- a/drivers/char/tpm/tpm-dev-common.c
+++ b/drivers/char/tpm/tpm-dev-common.c
@@ -33,7 +33,6 @@ static ssize_t tpm_dev_transmit(struct tpm_chip *chip, struct tpm_space *space,
struct tpm_header *header = (void *)buf;
ssize_t ret, len;

- mutex_lock(&chip->tpm_mutex);
ret = tpm2_prepare_space(chip, space, buf, bufsiz);
/* If the command is not implemented by the TPM, synthesize a
* response with a TPM2_RC_COMMAND_CODE return for user-space.
@@ -48,7 +47,7 @@ static ssize_t tpm_dev_transmit(struct tpm_chip *chip, struct tpm_space *space,
if (ret)
goto out_lock;

- len = tpm_transmit(chip, buf, bufsiz, TPM_TRANSMIT_UNLOCKED);
+ len = tpm_transmit(chip, buf, bufsiz, 0);
if (len < 0)
ret = len;

@@ -57,7 +56,6 @@ static ssize_t tpm_dev_transmit(struct tpm_chip *chip, struct tpm_space *space,
else
ret = tpm2_commit_space(chip, space, buf, &len);
out_lock:
- mutex_unlock(&chip->tpm_mutex);
return ret ? ret : len;
}

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 8d75c103f280..5865b9671d20 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -227,10 +227,6 @@ ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
memcpy(save, buf, save_size);

for (;;) {
- 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);

@@ -257,10 +253,6 @@ ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, false);

- if (!(flags & TPM_TRANSMIT_UNLOCKED) &&
- !(flags & TPM_TRANSMIT_NESTED))
- mutex_unlock(&chip->tpm_mutex);
-
if (ret < 0)
break;
rc = be32_to_cpu(header->return_code);
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 10a5bcf806aa..c7c06de651a0 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -488,14 +488,10 @@ extern struct idr dev_nums_idr;
/**
* enum tpm_transmit_flags - flags for tpm_transmit()
*
- * @TPM_TRANSMIT_UNLOCKED: do not lock the chip
- * @TPM_TRANSMIT_NESTED: discard setup steps (power management,
- * locality) including locking (i.e. implicit
- * UNLOCKED)
+ * %TPM_TRANSMIT_NESTED: discard setup steps (power management, locality)
*/
enum tpm_transmit_flags {
- TPM_TRANSMIT_UNLOCKED = BIT(0),
- TPM_TRANSMIT_NESTED = BIT(1),
+ TPM_TRANSMIT_NESTED = BIT(0),
};

ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index f2b0e5c52a57..d6abc964ef66 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -652,17 +652,12 @@ int tpm2_unseal_trusted(struct tpm_chip *chip,
u32 blob_handle;
int rc;

- mutex_lock(&chip->tpm_mutex);
- rc = tpm2_load_cmd(chip, payload, options, &blob_handle,
- TPM_TRANSMIT_UNLOCKED);
+ rc = tpm2_load_cmd(chip, payload, options, &blob_handle, 0);
if (rc)
- goto out;
+ return rc;

- rc = tpm2_unseal_cmd(chip, payload, options, blob_handle,
- TPM_TRANSMIT_UNLOCKED);
- tpm2_flush_context_cmd(chip, blob_handle, TPM_TRANSMIT_UNLOCKED);
-out:
- mutex_unlock(&chip->tpm_mutex);
+ rc = tpm2_unseal_cmd(chip, payload, options, blob_handle, 0);
+ tpm2_flush_context_cmd(chip, blob_handle, 0);
return rc;
}

diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index 46a58fda8cf5..ced1dc91ba6f 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -38,8 +38,7 @@ 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);
+ tpm2_flush_context_cmd(chip, space->session_tbl[i], 0);
}
}

@@ -83,7 +82,7 @@ static int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
body_size = sizeof(*ctx) + be16_to_cpu(ctx->blob_size);
tpm_buf_append(&tbuf, &buf[*offset], body_size);

- rc = tpm_transmit_cmd(chip, &tbuf, 4, TPM_TRANSMIT_UNLOCKED, NULL);
+ rc = tpm_transmit_cmd(chip, &tbuf, 4, 0, NULL);
if (rc < 0) {
dev_warn(&chip->dev, "%s: failed with a system error %d\n",
__func__, rc);
@@ -131,7 +130,7 @@ static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,

tpm_buf_append_u32(&tbuf, handle);

- rc = tpm_transmit_cmd(chip, &tbuf, 0, TPM_TRANSMIT_UNLOCKED, NULL);
+ rc = tpm_transmit_cmd(chip, &tbuf, 0, 0, NULL);
if (rc < 0) {
dev_warn(&chip->dev, "%s: failed with a system error %d\n",
__func__, rc);
@@ -167,8 +166,7 @@ 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);
+ tpm2_flush_context_cmd(chip, space->context_tbl[i], 0);

tpm2_flush_sessions(chip, space);
}
@@ -417,7 +415,7 @@ 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);
+ tpm2_flush_context_cmd(chip, phandle, 0);
dev_warn(&chip->dev, "%s: out of slots for 0x%08X\n", __func__,
phandle);
return -ENOMEM;
@@ -504,8 +502,7 @@ static int tpm2_save_space(struct tpm_chip *chip)
} else if (rc)
return rc;

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