[PATCH v2 8/8] tpm: move tpm2 code validation to tpm2-space.c

From: Tomas Winkler
Date: Sat Mar 10 2018 - 03:28:35 EST


Add new function tpm2_validate_command to tpm2-space.c
that wraps up open coded functionality from tpm_validate_command.

Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
---
drivers/char/tpm/tpm-interface.c | 31 ++-----------------------------
drivers/char/tpm/tpm.h | 1 +
drivers/char/tpm/tpm2-cmd.c | 1 +
drivers/char/tpm/tpm2-space.c | 32 ++++++++++++++++++++++++++++++++
4 files changed, 36 insertions(+), 29 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index d347ad8325c6..93f7c12d4c4d 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -52,40 +52,13 @@ static int tpm_validate_command(struct tpm_chip *chip,
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;
- }
+ if (chip->flags & TPM_CHIP_FLAG_TPM2 && space)
+ return tpm2_validate_command(chip, cmd, 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)
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 2b88aadc4743..15453a78a0d0 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -602,6 +602,7 @@ 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_validate_command(struct tpm_chip *chip, const u8 *cmd, size_t len);

extern const struct seq_operations tpm2_binary_b_measurements_seqops;

diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 80eb4bb5feef..6db13cf801b4 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -1112,3 +1112,4 @@ int tpm2_find_cc(struct tpm_chip *chip, u32 cc)

return -1;
}
+
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index 4e4014eabdb9..ed9eff948c05 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -263,6 +263,38 @@ static int tpm2_map_command(struct tpm_chip *chip, u32 cc, u8 *cmd)
return 0;
}

+int tpm2_validate_command(struct tpm_chip *chip, const u8 *cmd, size_t len)
+{
+ int i;
+ u32 cc;
+ u32 attrs;
+ unsigned int nr_handles;
+
+ if (len < TPM_HEADER_SIZE)
+ return -EINVAL;
+
+ if (!chip->nr_commands)
+ return 0;
+
+ cc = be32_to_cpup((__be32 *)(cmd + 6));
+
+ 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) {
+ dev_dbg(&chip->dev,
+ "%s: insufficient command length %zu", __func__, len);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u32 cc,
u8 *cmd)
{
--
2.14.3