From patchwork Mon May 10 10:16:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 433889 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=-19.4 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 7BE78C2BA04 for ; Mon, 10 May 2021 11:00:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2B4D661992 for ; Mon, 10 May 2021 11:00:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235133AbhEJLAH (ORCPT ); Mon, 10 May 2021 07:00:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:45210 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234110AbhEJKzz (ORCPT ); Mon, 10 May 2021 06:55:55 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 98AA561956; Mon, 10 May 2021 10:43:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620643439; bh=bbNokWG/OOTmYxR7K9p8wj7ATK+qZNNE29KRCIpvPAA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DuC/TWcDTA3+Bjale8IfoA5skOkLnDBPuB1rYXZ4HqZroLyMqkiLqY/pHpJsXWMlJ 6lP/R8WURbS7cqwgOCPLKmv+lR6bjuF7JvS2dIsT/6LKH0VbXdlbpwRUm5/VrID88G huheCngK3KJoE93/OirRTbGtbi1iMMc9Kuukzad8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Steven Rostedt (VMware)" Subject: [PATCH 5.11 016/342] ftrace: Handle commands when closing set_ftrace_filter file Date: Mon, 10 May 2021 12:16:46 +0200 Message-Id: <20210510102010.639536420@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510102010.096403571@linuxfoundation.org> References: <20210510102010.096403571@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 @@ -5631,7 +5631,10 @@ int ftrace_regex_release(struct inode *i 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);