Re: [PATCH v7 03/11] KEYS: trusted: remove redundant instance of tpm2_hash_map

[Jonathan McDowell <noodles@earth.li>]

On Thu, Nov 27, 2025 at 03:54:35PM +0200, Jarkko Sakkinen wrote:
>Trusted keys duplicates tpm2_hash_map from TPM driver internals. Implement
>and export `tpm2_find_hash_alg()` in order to address this glitch, and
>replace redundant code block with a call this new function.
>
>Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
>---
>v7:
>- A new patch.
>---
> drivers/char/tpm/tpm2-cmd.c               | 19 +++++++++++++++--
> include/linux/tpm.h                       |  7 ++-----
> security/keys/trusted-keys/trusted_tpm2.c | 25 +++++------------------
> 3 files changed, 24 insertions(+), 27 deletions(-)
>
>diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
>index 97501c567c34..1393bfbeca64 100644
>--- a/drivers/char/tpm/tpm2-cmd.c
>+++ b/drivers/char/tpm/tpm2-cmd.c
>@@ -18,7 +18,10 @@ static bool disable_pcr_integrity;
> module_param(disable_pcr_integrity, bool, 0444);
> MODULE_PARM_DESC(disable_pcr_integrity, "Disable integrity protection of TPM2_PCR_Extend");
>
>-static struct tpm2_hash tpm2_hash_map[] = {
>+static struct {
>+	unsigned int crypto_id;
>+	unsigned int alg_id;
>+} tpm2_hash_map[] = {
> 	{HASH_ALGO_SHA1, TPM_ALG_SHA1},
> 	{HASH_ALGO_SHA256, TPM_ALG_SHA256},
> 	{HASH_ALGO_SHA384, TPM_ALG_SHA384},
>@@ -26,6 +29,18 @@ static struct tpm2_hash tpm2_hash_map[] = {
> 	{HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
> };
>
>+int tpm2_find_hash_alg(unsigned int crypto_id)
>+{
>+	int i;
>+
>+	for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++)
>+		if (crypto_id == tpm2_hash_map[i].crypto_id)
>+			return tpm2_hash_map[i].alg_id;
>+
>+	return -EINVAL;
>+}
>+EXPORT_SYMBOL_GPL(tpm2_find_hash_alg);
>+
> int tpm2_get_timeouts(struct tpm_chip *chip)
> {
> 	chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
>@@ -490,7 +505,7 @@ static int tpm2_init_bank_info(struct tpm_chip *chip, u32 bank_index)
> 	for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
> 		enum hash_algo crypto_algo = tpm2_hash_map[i].crypto_id;
>
>-		if (bank->alg_id != tpm2_hash_map[i].tpm_id)
>+		if (bank->alg_id != tpm2_hash_map[i].alg_id)
> 			continue;
>
> 		bank->digest_size = hash_digest_size[crypto_algo];
>diff --git a/include/linux/tpm.h b/include/linux/tpm.h
>index 0e9e043f728c..e5fc7b73de2d 100644
>--- a/include/linux/tpm.h
>+++ b/include/linux/tpm.h
>@@ -410,11 +410,6 @@ enum tpm2_session_attributes {
> 	TPM2_SA_AUDIT			= BIT(7),
> };
>
>-struct tpm2_hash {
>-	unsigned int crypto_id;
>-	unsigned int tpm_id;
>-};
>-
> int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal);
> void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal);
> int tpm_buf_init_sized(struct tpm_buf *buf);
>@@ -465,6 +460,7 @@ static inline ssize_t tpm_ret_to_err(ssize_t ret)
>
> #if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)
>
>+unsigned int tpm2_alg_to_crypto_id(unsigned int alg_id);
> extern int tpm_is_tpm2(struct tpm_chip *chip);
> extern __must_check int tpm_try_get_ops(struct tpm_chip *chip);
> extern void tpm_put_ops(struct tpm_chip *chip);

This looks like an errant chunk? I can't see tpm2_alg_to_crypto_id 
defined or used?

>@@ -477,6 +473,7 @@ extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
> extern int tpm_get_random(struct tpm_chip *chip, u8 *data, size_t max);
> extern struct tpm_chip *tpm_default_chip(void);
> void tpm2_flush_context(struct tpm_chip *chip, u32 handle);
>+int tpm2_find_hash_alg(unsigned int crypto_id);
>
> static inline void tpm_buf_append_empty_auth(struct tpm_buf *buf, u32 handle)
> {
>diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
>index 024be262702f..3205732fb4b7 100644
>--- a/security/keys/trusted-keys/trusted_tpm2.c
>+++ b/security/keys/trusted-keys/trusted_tpm2.c
>@@ -18,14 +18,6 @@
>
> #include "tpm2key.asn1.h"
>
>-static struct tpm2_hash tpm2_hash_map[] = {
>-	{HASH_ALGO_SHA1, TPM_ALG_SHA1},
>-	{HASH_ALGO_SHA256, TPM_ALG_SHA256},
>-	{HASH_ALGO_SHA384, TPM_ALG_SHA384},
>-	{HASH_ALGO_SHA512, TPM_ALG_SHA512},
>-	{HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
>-};
>-
> static u32 tpm2key_oid[] = { 2, 23, 133, 10, 1, 5 };
>
> static int tpm2_key_encode(struct trusted_key_payload *payload,
>@@ -244,24 +236,17 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
> 	off_t offset = TPM_HEADER_SIZE;
> 	struct tpm_buf buf, sized;
> 	int blob_len = 0;
>-	u32 hash;
>+	int hash;
> 	u32 flags;
>-	int i;
> 	int rc;
>
>-	for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
>-		if (options->hash == tpm2_hash_map[i].crypto_id) {
>-			hash = tpm2_hash_map[i].tpm_id;
>-			break;
>-		}
>-	}
>-
>-	if (i == ARRAY_SIZE(tpm2_hash_map))
>-		return -EINVAL;
>-
> 	if (!options->keyhandle)
> 		return -EINVAL;
>
>+	hash = tpm2_find_hash_alg(options->hash);
>+	if (hash)
>+		return hash;
>+
> 	rc = tpm_try_get_ops(chip);
> 	if (rc)
> 		return rc;
>-- 
>2.52.0

J.

-- 
Design a system any fool can use, and only a fool will want to use it.