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

[Jarkko Sakkinen <jarkko@kernel.org>]

On Thu, Nov 27, 2025 at 05:45:55PM +0000, Jonathan McDowell wrote:
> 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?

It is! Thanks, will remove.

> 
> > @@ -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.

BR, Jarkko