[PATCH 4.4 44/56] test: firmware_class: report errors properly on failure

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Brian Norris <computersforpeace@xxxxxxxxx>

commit 47e0bbb7fa985a0f1b5794a8653fae4f8f49de77 upstream.

request_firmware() failures currently won't get reported at all (the
error code is discarded). What's more, we get confusing messages, like:

    # echo -n notafile > /sys/devices/virtual/misc/test_firmware/trigger_request
    [ 8280.311856] test_firmware: loading 'notafile'
    [ 8280.317042] test_firmware: load of 'notafile' failed: -2
    [ 8280.322445] test_firmware: loaded: 0
    # echo $?
    0

Report the failures via write() errors, and don't say we "loaded"
anything.

Signed-off-by: Brian Norris <computersforpeace@xxxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 lib/test_firmware.c |   11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

--- a/lib/test_firmware.c
+++ b/lib/test_firmware.c
@@ -65,14 +65,19 @@ static ssize_t trigger_request_store(str
 	release_firmware(test_firmware);
 	test_firmware = NULL;
 	rc = request_firmware(&test_firmware, name, dev);
-	if (rc)
+	if (rc) {
 		pr_info("load of '%s' failed: %d\n", name, rc);
-	pr_info("loaded: %zu\n", test_firmware ? test_firmware->size : 0);
+		goto out;
+	}
+	pr_info("loaded: %zu\n", test_firmware->size);
+	rc = count;
+
+out:
 	mutex_unlock(&test_fw_mutex);
 
 	kfree(name);
 
-	return count;
+	return rc;
 }
 static DEVICE_ATTR_WO(trigger_request);