From: "Daniel P. Smith" <dpsmith@apertussolutions.com>
To: Jason Gunthorpe <jgg@ziepe.ca>,
linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: "Daniel P. Smith" <dpsmith@apertussolutions.com>,
Ross Philipson <ross.philipson@oracle.com>,
Peter Huewe <peterhuewe@gmx.de>,
Jarkko Sakkinen <jarkko@kernel.org>
Subject: [PATCH 3/3] tpm: make locality request return value consistent
Date: Wed, 31 Jan 2024 12:08:23 -0500 [thread overview]
Message-ID: <20240131170824.6183-4-dpsmith@apertussolutions.com> (raw)
In-Reply-To: <20240131170824.6183-1-dpsmith@apertussolutions.com>
The function tpm_tis_request_locality() is expected to return the locality
value that was requested, or a negative error code upon failure. If it is called
while locality_count of struct tis_data is non-zero, no actual locality request
will be sent. Because the ret variable is initially set to 0, the
locality_count will still get increased, and the function will return 0. For a
caller, this would indicate that locality 0 was successfully requested and not
the state changes just mentioned.
Additionally, the function __tpm_tis_request_locality() provides inconsistent
error codes. It will provide either a failed IO write or a -1 should it have
timed out waiting for locality request to succeed.
This commit changes __tpm_tis_request_locality() to return valid negative error
codes to reflect the reason it fails. It then adjusts the return value check in
tpm_tis_request_locality() to check for a non-negative return value before
incrementing locality_cout. In addition, the initial value of the ret value is
set to a negative error to ensure the check does not pass if
__tpm_tis_request_locality() is not called.
Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
---
drivers/char/tpm/tpm_tis_core.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 5709f87991d9..352fefc07823 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -208,7 +208,7 @@ static int __tpm_tis_request_locality(struct tpm_chip *chip, int l)
again:
timeout = stop - jiffies;
if ((long)timeout <= 0)
- return -1;
+ return -EBUSY;
rc = wait_event_interruptible_timeout(priv->int_queue,
(check_locality
(chip, l)),
@@ -227,18 +227,21 @@ static int __tpm_tis_request_locality(struct tpm_chip *chip, int l)
tpm_msleep(TPM_TIMEOUT);
} while (time_before(jiffies, stop));
}
- return -1;
+ return -EBUSY;
}
static int tpm_tis_request_locality(struct tpm_chip *chip, int l)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
- int ret = 0;
+ int ret = -EBUSY;
+
+ if (l < 0 || l > TPM_MAX_LOCALITY)
+ return -EINVAL;
mutex_lock(&priv->locality_count_mutex);
if (priv->locality_count == 0)
ret = __tpm_tis_request_locality(chip, l);
- if (!ret)
+ if (ret >= 0)
priv->locality_count++;
mutex_unlock(&priv->locality_count_mutex);
return ret;
--
2.30.2
next prev parent reply other threads:[~2024-01-31 17:09 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20240131170824.6183-1-dpsmith@apertussolutions.com>
2024-01-31 17:08 ` [PATCH 1/3] tpm: protect against locality counter underflow Daniel P. Smith
2024-02-01 22:21 ` Jarkko Sakkinen
2024-02-02 3:08 ` Lino Sanfilippo
2024-02-12 20:05 ` Jarkko Sakkinen
2024-02-19 17:54 ` Daniel P. Smith
2024-02-20 18:42 ` Alexander Steffen
2024-02-20 19:04 ` Jarkko Sakkinen
2024-02-20 20:54 ` Lino Sanfilippo
2024-02-20 22:23 ` Jarkko Sakkinen
2024-02-20 23:19 ` Lino Sanfilippo
2024-02-21 0:40 ` Jarkko Sakkinen
2024-02-23 1:58 ` Daniel P. Smith
2024-02-23 12:58 ` Jarkko Sakkinen
2024-02-25 11:23 ` Daniel P. Smith
2024-02-26 9:39 ` Jarkko Sakkinen
2024-02-20 22:26 ` Jarkko Sakkinen
2024-02-20 22:31 ` Jarkko Sakkinen
2024-02-20 23:26 ` Lino Sanfilippo
2024-02-21 0:42 ` Jarkko Sakkinen
2024-02-21 12:37 ` James Bottomley
2024-02-21 19:43 ` Jarkko Sakkinen
2024-02-21 19:45 ` Jarkko Sakkinen
2024-02-22 9:06 ` James Bottomley
2024-02-22 23:49 ` Jarkko Sakkinen
2024-02-23 1:57 ` Daniel P. Smith
2024-02-23 20:40 ` Jarkko Sakkinen
2024-02-23 20:42 ` Jarkko Sakkinen
2024-02-23 1:57 ` Daniel P. Smith
2024-02-23 20:50 ` Jarkko Sakkinen
2024-02-20 22:57 ` ross.philipson
2024-02-20 23:10 ` Jarkko Sakkinen
2024-02-20 23:13 ` Jarkko Sakkinen
2024-02-23 1:56 ` Daniel P. Smith
2024-02-23 20:44 ` Jarkko Sakkinen
2024-02-24 2:34 ` Lino Sanfilippo
2024-02-26 9:38 ` Jarkko Sakkinen
2024-02-23 1:55 ` Daniel P. Smith
2024-02-26 12:43 ` Alexander Steffen
2024-02-24 2:06 ` Lino Sanfilippo
2024-02-23 0:01 ` Jarkko Sakkinen
2024-01-31 17:08 ` [PATCH 2/3] tpm: ensure tpm is in known state at startup Daniel P. Smith
2024-02-01 22:33 ` Jarkko Sakkinen
2024-02-19 19:17 ` Daniel P. Smith
2024-02-19 20:17 ` Jarkko Sakkinen
2024-01-31 17:08 ` Daniel P. Smith [this message]
2024-02-01 22:49 ` [PATCH 3/3] tpm: make locality request return value consistent Jarkko Sakkinen
2024-02-19 20:29 ` Daniel P. Smith
2024-02-19 20:45 ` Jarkko Sakkinen
2024-02-20 18:57 ` Alexander Steffen
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