From patchwork Thu May 20 09:20:50 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: 444166 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 3EE0BC43470 for ; Thu, 20 May 2021 10:50:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2CACE61261 for ; Thu, 20 May 2021 10:50:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238324AbhETKvU (ORCPT ); Thu, 20 May 2021 06:51:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:48432 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238452AbhETKsq (ORCPT ); Thu, 20 May 2021 06:48:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 39B7161CBB; Thu, 20 May 2021 09:58:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621504738; bh=Ab0KjWe/3oPlBT00cEJsIbOdiOuPeGiXJsW6+7XFwbw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kurvXe9KZlNFHfCILp3MemrhkxcLdH5yfaO/JUx5Fq4KniFTdkItZOcVaCZYqrkCI lTN1a3dcztu2p077GEY5BWmi3aOoQ+yVysuiJyxomT1YQrxUpjyMWyWQWn1Fz0iNvk STiicMV1hCMAyn5Xb9BaAR0xFNAS5GGa3gvpyv7M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Steven Rostedt (VMware)" Subject: [PATCH 4.9 058/240] ftrace: Handle commands when closing set_ftrace_filter file Date: Thu, 20 May 2021 11:20:50 +0200 Message-Id: <20210520092110.638571049@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092108.587553970@linuxfoundation.org> References: <20210520092108.587553970@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 @@ -4486,8 +4486,11 @@ 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);