We're essentially just doing an open-coded kstrndup(). The only
differences are with what happens after the first '\0' character, but
request_firmware() doesn't care about that.
Suggested-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>

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: NBrian Norris <computersforpeace@gmail.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>

This provides a simple interface to trigger the firmware_class loader
to test built-in, filesystem, and user helper modes. Additionally adds
tests via the new interface to the selftests tree.
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>