[ Upstream commit9037c3bde6] The function simple_write_to_buffer() doesn't add string termination at the end of buf, we need to handle it on our own. This change refers to the function tokenize_input() in debug.c and the function sof_dfsentry_trace_filter_write() in trace.c. Fixes:091c12e1f5("ASoC: SOF: debug: add new debugfs entries for IPC flood test") Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Signed-off-by: Hui Wang <hui.wang@canonical.com> Link: https://lore.kernel.org/r/20210208103857.75705-1-hui.wang@canonical.com Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>