Re: [PATCH v3 08/16] tpm: move tpm_validate_commmand() to tpm2-space.c

From: Stefan Berger
Date: Mon Nov 05 2018 - 17:36:13 EST

On 11/4/18 8:45 PM, Jarkko Sakkinen wrote:
Move tpm_validate_command() to tpm2-space.c and make it part of the
tpm2_prepare_space() flow. Make cc resolution as part of the TPM space
functionality in order to detach it from rest of the tpm_transmit()
flow.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm-interface.c | 72 +++++++-------------------------
drivers/char/tpm/tpm.h | 9 ++--
drivers/char/tpm/tpm2-space.c | 54 +++++++++++++++++++++---
3 files changed, 68 insertions(+), 67 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 422e3bb0bd3d..3bf0c51b7b4f 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -62,47 +62,6 @@ unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
}
EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);

-static int tpm_validate_command(struct tpm_chip *chip,
- struct tpm_space *space,
- const u8 *cmd,
- size_t len)
-{
- const struct tpm_input_header *header = (const void *)cmd;
- int i;
- u32 cc;
- u32 attrs;
- unsigned int nr_handles;
-
- if (len < TPM_HEADER_SIZE)
- return -EINVAL;
-
- if (!space)
- return 0;
-
- if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) {
- cc = be32_to_cpu(header->ordinal);
-
- i = tpm2_find_cc(chip, cc);
- if (i < 0) {
- dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
- cc);
- return -EOPNOTSUPP;
- }
-
- attrs = chip->cc_attrs_tbl[i];
- nr_handles =
- 4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
- if (len < TPM_HEADER_SIZE + 4 * nr_handles)
- goto err_len;
- }
-
- return 0;
-err_len:
- dev_dbg(&chip->dev,
- "%s: insufficient command length %zu", __func__, len);
- return -EINVAL;
-}
-
static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
{
int rc;
@@ -172,20 +131,8 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
u32 count, ordinal;
unsigned long stop;

- rc = tpm_validate_command(chip, space, buf, bufsiz);
- if (rc == -EINVAL)
- return rc;
- /*
- * If the command is not implemented by the TPM, synthesize a
- * response with a TPM2_RC_COMMAND_CODE return for user-space.
- */
- if (rc == -EOPNOTSUPP) {
- header->length = cpu_to_be32(sizeof(*header));
- header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
- header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE |
- TSS2_RESMGR_TPM_RC_LAYER);
- return sizeof(*header);
- }
+ if (bufsiz < TPM_HEADER_SIZE)
+ return -EINVAL;

if (bufsiz > TPM_BUFSIZE)
bufsiz = TPM_BUFSIZE;
@@ -200,7 +147,18 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
return -E2BIG;
}

- rc = tpm2_prepare_space(chip, space, ordinal, buf);
+ rc = 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.
+ */
+ if (rc == -EOPNOTSUPP) {
+ header->length = cpu_to_be32(sizeof(*header));
+ header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
+ header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE |
+ TSS2_RESMGR_TPM_RC_LAYER);
+ return sizeof(*header);
+ }
if (rc)
return rc;

@@ -251,7 +209,7 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
if (rc)
tpm2_flush_space(chip);
else
- rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
+ rc = tpm2_commit_space(chip, space, buf, &len);

return rc ? rc : len;
}
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 229ac42b644e..8503dd261897 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -264,6 +264,7 @@ struct tpm_chip {
#endif /* CONFIG_ACPI */

struct tpm_space work_space;
+ u32 last_cc;
u32 nr_commands;
u32 *cc_attrs_tbl;

@@ -580,10 +581,10 @@ int tpm2_find_cc(struct tpm_chip *chip, u32 cc);
int tpm2_init_space(struct tpm_space *space);
void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space);
void tpm2_flush_space(struct tpm_chip *chip);
-int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u32 cc,
- u8 *cmd);
-int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
- u32 cc, u8 *buf, size_t *bufsiz);
+int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u8 *cmd,
+ size_t cmdsiz);
+int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space, u8 *buf,
+ size_t *bufsiz);

int tpm_bios_log_setup(struct tpm_chip *chip);
void tpm_bios_log_teardown(struct tpm_chip *chip);
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index 3d5f9577e5de..20c295fadd50 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -264,14 +264,55 @@ static int tpm2_map_command(struct tpm_chip *chip, u32 cc, u8 *cmd)
return 0;
}

-int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u32 cc,
- u8 *cmd)
+static int tpm_validate_command(struct tpm_chip *chip, struct tpm_space *space,
+ const u8 *cmd, size_t len)


Nit: len -> cmdsiz (like below)


+{
+ const struct tpm_input_header *header = (const void *)cmd;
+ int i;
+ u32 cc;
+ u32 attrs;
+ unsigned int nr_handles;
+
+ if (len < TPM_HEADER_SIZE)
+ return -EINVAL;
+
+ if (chip->nr_commands) {
+ cc = be32_to_cpu(header->ordinal);
+
+ i = tpm2_find_cc(chip, cc);
+ if (i < 0) {
+ dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
+ cc);
+ return -EOPNOTSUPP;
+ }
+
+ attrs = chip->cc_attrs_tbl[i];
+ nr_handles =
+ 4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
+ if (len < TPM_HEADER_SIZE + 4 * nr_handles)
+ goto err_len;
+ }
+
+ return cc;
+err_len:
+ dev_dbg(&chip->dev, "%s: insufficient command length %zu", __func__,
+ len);
+ return -EINVAL;
+}
+
+int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u8 *cmd,
+ size_t cmdsiz)
{
int rc;
+ int cc;

if (!space)
return 0;

+ cc = tpm_validate_command(chip, space, cmd, cmdsiz);
+ if (cc < 0)
+ return cc;
+
memcpy(&chip->work_space.context_tbl, &space->context_tbl,
sizeof(space->context_tbl));
memcpy(&chip->work_space.session_tbl, &space->session_tbl,
@@ -291,6 +332,7 @@ int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u32 cc,
return rc;
}

+ chip->last_cc = cc;
return 0;
}

@@ -489,8 +531,8 @@ static int tpm2_save_space(struct tpm_chip *chip)
return 0;
}

-int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
- u32 cc, u8 *buf, size_t *bufsiz)
+int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space, u8 *buf,
+ size_t *bufsiz)
{
struct tpm_output_header *header = (void *)buf;
int rc;
@@ -498,13 +540,13 @@ int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
if (!space)
return 0;

- rc = tpm2_map_response_header(chip, cc, buf, *bufsiz);
+ rc = tpm2_map_response_header(chip, chip->last_cc, buf, *bufsiz);
if (rc) {
tpm2_flush_space(chip);
goto out;
}

- rc = tpm2_map_response_body(chip, cc, buf, *bufsiz);
+ rc = tpm2_map_response_body(chip, chip->last_cc, buf, *bufsiz);
if (rc) {
tpm2_flush_space(chip);
goto out;

Rest looks good.

Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>