From patchwork Thu May 20 09:19:43 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: 445555 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 DA5FAC43461 for ; Thu, 20 May 2021 10:26:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BBB5A613F5 for ; Thu, 20 May 2021 10:26:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235696AbhETK1t (ORCPT ); Thu, 20 May 2021 06:27:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:55694 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236349AbhETKZm (ORCPT ); Thu, 20 May 2021 06:25:42 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2345761480; Thu, 20 May 2021 09:49:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621504195; bh=qivATiHf16OvUEzdc6XayNzgWAB5IFNxqPbnfVlp3n4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p44P0yZWJMy7f4iY1K9UuThyyfrgrv0y8HdJTnZ+LSaFiclvDfRQo62Gk1cOoyPIV oJrTdk87LQYLqqSx8YqbbIgS6/COm9qIe8svnlUDO8Rk+dcwxK+Qelp81LPCi6agPj C71EUAmlPhpcvi6Pyax2XBh9wROCJKoYknhJC3+Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Steven Rostedt (VMware)" Subject: [PATCH 4.14 091/323] ftrace: Handle commands when closing set_ftrace_filter file Date: Thu, 20 May 2021 11:19:43 +0200 Message-Id: <20210520092123.215653929@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092120.115153432@linuxfoundation.org> References: <20210520092120.115153432@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 @@ -5096,8 +5096,11 @@ 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, parser->buffer, + parser->idx, enable); } trace_parser_put(parser);