[PATCH] security/keys/trusted: Allow operation without hardware TPM

Rather than fail initialization of the trusted.ko module, arrange for the module to load, but rely on trusted_instantiate() to fail trusted-key operations. Fixes: 240730437deb ("KEYS: trusted: explicitly use tpm_chip structure...") Cc: Roberto Sassu <roberto.sassu(a)huawei.com&gt; Cc: Jarkko Sakkinen <jarkko.sakkinen(a)linux.intel.com&gt; Cc: James Bottomley <jejb(a)linux.ibm.com&gt; Cc: Jarkko Sakkinen <jarkko.sakkinen(a)linux.intel.com&gt; Cc: Mimi Zohar <zohar(a)linux.ibm.com&gt; Cc: David Howells <dhowells(a)redhat.com&gt; Signed-off-by: Dan Williams <dan.j.williams(a)intel.com&gt; --- security/keys/trusted.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/security/keys/trusted.c b/security/keys/trusted.c index bcc9c6ead7fd..d959597a688e 100644 --- a/security/keys/trusted.c +++ b/security/keys/trusted.c @@ -45,6 +45,13 @@ struct sdesc { static struct crypto_shash *hashalg; static struct crypto_shash *hmacalg; +static struct device *chip_dev(struct tpm_chip *chip) +{ + if (chip) + return &chip->dev; + return NULL; +} + static struct sdesc *init_sdesc(struct crypto_shash *alg) { struct sdesc *sdesc; @@ -1224,6 +1231,14 @@ static int __init init_digests(void) int ret; int i; + /* + * Hardware tpm operations are disabled, but allow the software + * module to initialize, and depend on trusted_instantiate() to + * fail any attempts to access the missing hardware. + */ + if (!chip) + return 0; + ret = tpm_get_random(chip, digest, TPM_MAX_DIGEST_SIZE); if (ret < 0) return ret; @@ -1246,8 +1261,6 @@ static int __init init_trusted(void) int ret; chip = tpm_default_chip(); - if (!chip) - return -ENOENT; ret = init_digests(); if (ret < 0) goto err_put; @@ -1263,13 +1276,13 @@ static int __init init_trusted(void) err_free: kfree(digests); err_put: - put_device(&chip->dev); + put_device(chip_dev(chip)); return ret; } static void __exit cleanup_trusted(void) { - put_device(&chip->dev); + put_device(chip_dev(chip)); kfree(digests); trusted_shash_release(); unregister_key_type(&key_type_trusted);