firmware loader: Fix the race FW_STATUS_DONE is followed by class_timeout
There is a race as below when calling request_firmware(): CPU1 CPU2 write 0 > loading mutex_lock(&fw_lock) ... set_bit FW_STATUS_DONE class_timeout is coming set_bit FW_STATUS_ABORT complete_all &completion ... mutex_unlock(&fw_lock) In this time, the bit FW_STATUS_DONE and FW_STATUS_ABORT are set, and request_firmware() will return failure due to condition in _request_firmware_load(): if (!buf->size || test_bit(FW_STATUS_ABORT, &buf->status)) retval = -ENOENT; But from the above scenerio, it should be a successful requesting. So we need judge if the bit FW_STATUS_DONE is already set before calling fw_load_abort() in timeout function. As Ming's proposal, we need change the timer into sched_work to benefit from using &fw_lock mutex also. Signed-off-by: liu chuansheng <chuansheng.liu@intel.com> Acked-by: Ming Lei <ming.lei@canonical.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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@ -143,7 +143,7 @@ struct fw_cache_entry {
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};
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struct firmware_priv {
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struct timer_list timeout;
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struct delayed_work timeout_work;
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bool nowait;
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struct device dev;
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struct firmware_buf *buf;
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@ -667,11 +667,18 @@ static struct bin_attribute firmware_attr_data = {
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.write = firmware_data_write,
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};
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static void firmware_class_timeout(u_long data)
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static void firmware_class_timeout_work(struct work_struct *work)
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{
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struct firmware_priv *fw_priv = (struct firmware_priv *) data;
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struct firmware_priv *fw_priv = container_of(work,
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struct firmware_priv, timeout_work.work);
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mutex_lock(&fw_lock);
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if (test_bit(FW_STATUS_DONE, &(fw_priv->buf->status))) {
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mutex_unlock(&fw_lock);
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return;
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}
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fw_load_abort(fw_priv);
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mutex_unlock(&fw_lock);
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}
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static struct firmware_priv *
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@ -690,8 +697,8 @@ fw_create_instance(struct firmware *firmware, const char *fw_name,
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fw_priv->nowait = nowait;
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fw_priv->fw = firmware;
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setup_timer(&fw_priv->timeout,
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firmware_class_timeout, (u_long) fw_priv);
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INIT_DELAYED_WORK(&fw_priv->timeout_work,
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firmware_class_timeout_work);
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f_dev = &fw_priv->dev;
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@ -858,7 +865,9 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
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dev_dbg(f_dev->parent, "firmware: direct-loading"
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" firmware %s\n", buf->fw_id);
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mutex_lock(&fw_lock);
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set_bit(FW_STATUS_DONE, &buf->status);
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mutex_unlock(&fw_lock);
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complete_all(&buf->completion);
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direct_load = 1;
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goto handle_fw;
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@ -894,15 +903,14 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
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dev_set_uevent_suppress(f_dev, false);
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dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
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if (timeout != MAX_SCHEDULE_TIMEOUT)
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mod_timer(&fw_priv->timeout,
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round_jiffies_up(jiffies + timeout));
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schedule_delayed_work(&fw_priv->timeout_work, timeout);
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kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
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}
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wait_for_completion(&buf->completion);
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del_timer_sync(&fw_priv->timeout);
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cancel_delayed_work_sync(&fw_priv->timeout_work);
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handle_fw:
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mutex_lock(&fw_lock);
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