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authorJames Bottomley <James.Bottomley@HansenPartnership.com>2020-05-28 11:10:57 -0700
committerJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2020-07-02 17:48:59 +0300
commit7862840219058436b80029a0263fd1ef065fb1b3 (patch)
tree5862442d1f898b7c6ff9726670e4a5c135dfb7dc /drivers/char
parentcd77006e01b3198c75fb7819b3d0ff89709539bb (diff)
tpm: Fix TIS locality timeout problems
It has been reported that some TIS based TPMs are giving unexpected errors when using the O_NONBLOCK path of the TPM device. The problem is that some TPMs don't like it when you get and then relinquish a locality (as the tpm_try_get_ops()/tpm_put_ops() pair does) without sending a command. This currently happens all the time in the O_NONBLOCK write path. Fix this by moving the tpm_try_get_ops() further down the code to after the O_NONBLOCK determination is made. This is safe because the priv->buffer_mutex still protects the priv state being modified. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=206275 Fixes: d23d12484307 ("tpm: fix invalid locking in NONBLOCKING mode") Reported-by: Mario Limonciello <Mario.Limonciello@dell.com> Tested-by: Alex Guzman <alex@guzman.io> Cc: stable@vger.kernel.org Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/tpm/tpm-dev-common.c19
1 files changed, 9 insertions, 10 deletions
diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c
index 87f449340202..1784530b8387 100644
--- a/drivers/char/tpm/tpm-dev-common.c
+++ b/drivers/char/tpm/tpm-dev-common.c
@@ -189,15 +189,6 @@ ssize_t tpm_common_write(struct file *file, const char __user *buf,
goto out;
}
- /* atomic tpm command send and result receive. We only hold the ops
- * lock during this period so that the tpm can be unregistered even if
- * the char dev is held open.
- */
- if (tpm_try_get_ops(priv->chip)) {
- ret = -EPIPE;
- goto out;
- }
-
priv->response_length = 0;
priv->response_read = false;
*off = 0;
@@ -211,11 +202,19 @@ ssize_t tpm_common_write(struct file *file, const char __user *buf,
if (file->f_flags & O_NONBLOCK) {
priv->command_enqueued = true;
queue_work(tpm_dev_wq, &priv->async_work);
- tpm_put_ops(priv->chip);
mutex_unlock(&priv->buffer_mutex);
return size;
}
+ /* atomic tpm command send and result receive. We only hold the ops
+ * lock during this period so that the tpm can be unregistered even if
+ * the char dev is held open.
+ */
+ if (tpm_try_get_ops(priv->chip)) {
+ ret = -EPIPE;
+ goto out;
+ }
+
ret = tpm_dev_transmit(priv->chip, priv->space, priv->data_buffer,
sizeof(priv->data_buffer));
tpm_put_ops(priv->chip);