From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF5F7C433B4 for ; Wed, 5 May 2021 14:48:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9AD14613C3 for ; Wed, 5 May 2021 14:48:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233394AbhEEOtT (ORCPT ); Wed, 5 May 2021 10:49:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:36624 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233380AbhEEOtR (ORCPT ); Wed, 5 May 2021 10:49:17 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9B335613BA; Wed, 5 May 2021 14:48:20 +0000 (UTC) Date: Wed, 5 May 2021 10:48:18 -0400 From: Steven Rostedt To: LKML Cc: Ingo Molnar , Andrew Morton , Jiri Olsa Subject: [PATCH] ftrace: Handle commands when closing set_ftrace_filter file Message-ID: <20210505104818.24358ef7@gandalf.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Steven Rostedt (VMware)" # echo switch_mm:traceoff > /sys/kernel/tracing/set_ftrace_filter will cause switch_mm to stop tracing by the traceoff command. # echo -n switch_mm:traceoff > /sys/kernel/tracing/set_ftrace_filter does nothing. The reason is that the parsing in the write function only processes commands if it finished parsing (there is white space written after the command). That's to handle: write(fd, "switch_mm:", 10); write(fd, "traceoff", 8); cases, where the command is broken over multiple writes. The problem is if the file descriptor is closed, then the write call is not processed, and the command needs to be processed in the release code. The release code can handle matching of functions, but does not handle commands. Cc: stable@vger.kernel.org Fixes: eda1e32855656 ("tracing: handle broken names in ftrace filter") Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/ftrace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 057e962ca5ce..c57508445faa 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5591,7 +5591,10 @@ int ftrace_regex_release(struct inode *inode, struct file *file) parser = &iter->parser; if (trace_parser_loaded(parser)) { - ftrace_match_records(iter->hash, parser->buffer, parser->idx); + int enable = !(iter->flags & FTRACE_ITER_NOTRACE); + + ftrace_process_regex(iter, parser->buffer, + parser->idx, enable); } trace_parser_put(parser); -- 2.29.2