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path: root/drivers/char/tpm/tpm-dev-common.c
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Diffstat (limited to 'drivers/char/tpm/tpm-dev-common.c')
-rw-r--r--drivers/char/tpm/tpm-dev-common.c52
1 files changed, 36 insertions, 16 deletions
diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c
index 99b5133a9d05..5eecad233ea1 100644
--- a/drivers/char/tpm/tpm-dev-common.c
+++ b/drivers/char/tpm/tpm-dev-common.c
@@ -40,7 +40,7 @@ static void tpm_async_work(struct work_struct *work)
tpm_put_ops(priv->chip);
if (ret > 0) {
- priv->data_pending = ret;
+ priv->response_length = ret;
mod_timer(&priv->user_read_timer, jiffies + (120 * HZ));
}
mutex_unlock(&priv->buffer_mutex);
@@ -63,7 +63,8 @@ static void tpm_timeout_work(struct work_struct *work)
timeout_work);
mutex_lock(&priv->buffer_mutex);
- priv->data_pending = 0;
+ priv->response_read = true;
+ priv->response_length = 0;
memset(priv->data_buffer, 0, sizeof(priv->data_buffer));
mutex_unlock(&priv->buffer_mutex);
wake_up_interruptible(&priv->async_wait);
@@ -74,6 +75,7 @@ void tpm_common_open(struct file *file, struct tpm_chip *chip,
{
priv->chip = chip;
priv->space = space;
+ priv->response_read = true;
mutex_init(&priv->buffer_mutex);
timer_setup(&priv->user_read_timer, user_reader_timeout, 0);
@@ -90,22 +92,35 @@ ssize_t tpm_common_read(struct file *file, char __user *buf,
ssize_t ret_size = 0;
int rc;
- del_singleshot_timer_sync(&priv->user_read_timer);
- flush_work(&priv->timeout_work);
mutex_lock(&priv->buffer_mutex);
- if (priv->data_pending) {
- ret_size = min_t(ssize_t, size, priv->data_pending);
- if (ret_size > 0) {
- rc = copy_to_user(buf, priv->data_buffer, ret_size);
- memset(priv->data_buffer, 0, priv->data_pending);
- if (rc)
- ret_size = -EFAULT;
+ if (priv->response_length) {
+ priv->response_read = true;
+
+ ret_size = min_t(ssize_t, size, priv->response_length);
+ if (!ret_size) {
+ priv->response_length = 0;
+ goto out;
}
- priv->data_pending = 0;
+ rc = copy_to_user(buf, priv->data_buffer + *off, ret_size);
+ if (rc) {
+ memset(priv->data_buffer, 0, TPM_BUFSIZE);
+ priv->response_length = 0;
+ ret_size = -EFAULT;
+ } else {
+ memset(priv->data_buffer + *off, 0, ret_size);
+ priv->response_length -= ret_size;
+ *off += ret_size;
+ }
}
+out:
+ if (!priv->response_length) {
+ *off = 0;
+ del_singleshot_timer_sync(&priv->user_read_timer);
+ flush_work(&priv->timeout_work);
+ }
mutex_unlock(&priv->buffer_mutex);
return ret_size;
}
@@ -125,7 +140,8 @@ ssize_t tpm_common_write(struct file *file, const char __user *buf,
* tpm_read or a user_read_timer timeout. This also prevents split
* buffered writes from blocking here.
*/
- if (priv->data_pending != 0 || priv->command_enqueued) {
+ if ((!priv->response_read && priv->response_length) ||
+ priv->command_enqueued) {
ret = -EBUSY;
goto out;
}
@@ -150,6 +166,10 @@ ssize_t tpm_common_write(struct file *file, const char __user *buf,
goto out;
}
+ priv->response_length = 0;
+ priv->response_read = false;
+ *off = 0;
+
/*
* If in nonblocking mode schedule an async job to send
* the command return the size.
@@ -168,7 +188,7 @@ ssize_t tpm_common_write(struct file *file, const char __user *buf,
tpm_put_ops(priv->chip);
if (ret > 0) {
- priv->data_pending = ret;
+ priv->response_length = ret;
mod_timer(&priv->user_read_timer, jiffies + (120 * HZ));
ret = size;
}
@@ -184,7 +204,7 @@ __poll_t tpm_common_poll(struct file *file, poll_table *wait)
poll_wait(file, &priv->async_wait, wait);
- if (priv->data_pending)
+ if (!priv->response_read || priv->response_length)
mask = EPOLLIN | EPOLLRDNORM;
else
mask = EPOLLOUT | EPOLLWRNORM;
@@ -201,7 +221,7 @@ void tpm_common_release(struct file *file, struct file_priv *priv)
del_singleshot_timer_sync(&priv->user_read_timer);
flush_work(&priv->timeout_work);
file->private_data = NULL;
- priv->data_pending = 0;
+ priv->response_length = 0;
}
int __init tpm_dev_common_init(void)