From patchwork Thu May 20 09:21:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 445317 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 52517C433B4 for ; Thu, 20 May 2021 11:12:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 377B46100A for ; Thu, 20 May 2021 11:12:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240035AbhETLNU (ORCPT ); Thu, 20 May 2021 07:13:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:55128 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239687AbhETLLS (ORCPT ); Thu, 20 May 2021 07:11:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A113061D4B; Thu, 20 May 2021 10:07:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621505243; bh=ZZ0GxiYV5eYLE4XtpHMTuZPceoQ/HvtP+ZFnq2OETPU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DYLUUwB11i1RC1nsq064s/K7E/kRveh9dppi3UQ9M+LoHpp7aS9LujCHqujddqXn6 PIU2AmzCnu7Vh7DQQP3iq8AZERLYeEon+Gj6EnigrouFa74Dm/RrMF6OgDc3W78Hk6 8PhfY/cM5aLyxuzZz6JywVyXDAfgzLSrNezMcvOQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Steven Rostedt (VMware)" Subject: [PATCH 4.4 047/190] ftrace: Handle commands when closing set_ftrace_filter file Date: Thu, 20 May 2021 11:21:51 +0200 Message-Id: <20210520092103.728121583@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092102.149300807@linuxfoundation.org> References: <20210520092102.149300807@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Steven Rostedt (VMware) commit 8c9af478c06bb1ab1422f90d8ecbc53defd44bc3 upstream. # 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) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/ftrace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -4401,8 +4401,11 @@ int ftrace_regex_release(struct inode *i parser = &iter->parser; if (trace_parser_loaded(parser)) { + int enable = !(iter->flags & FTRACE_ITER_NOTRACE); + parser->buffer[parser->idx] = 0; - ftrace_match_records(iter->hash, parser->buffer, parser->idx); + ftrace_process_regex(iter->hash, parser->buffer, + parser->idx, enable); } trace_parser_put(parser);