From patchwork Mon May 10 10:18:18 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 434122 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 9975AC433ED for ; Mon, 10 May 2021 10:23:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6773861466 for ; Mon, 10 May 2021 10:23:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231217AbhEJKY7 (ORCPT ); Mon, 10 May 2021 06:24:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:57994 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231173AbhEJKY4 (ORCPT ); Mon, 10 May 2021 06:24:56 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5F35961139; Mon, 10 May 2021 10:23:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620642231; bh=osjNYQX8zT5OmlsRtR+VIAdpcuHh35ByBCH0nX6lV70=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Gc3CdPqyHF0IqUkgvAEaOl4YIVzBSvyGVNYJ9F5emvq+bvbWGvR6Wxak8m4wvS9tO zirQNaFNIJXhPujTr2ogLOUvSmArwo+Kbi+Zrwcx/Gc7E7G3vbIqc7QmwnDZcjwG9T Bw0KDX+DCa+F6Cz6XhRdIOwqzeg51IaA9aIHHq2o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Steven Rostedt (VMware)" Subject: [PATCH 5.4 004/184] ftrace: Handle commands when closing set_ftrace_filter file Date: Mon, 10 May 2021 12:18:18 +0200 Message-Id: <20210510101950.350570332@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510101950.200777181@linuxfoundation.org> References: <20210510101950.200777181@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 @@ -5053,7 +5053,10 @@ 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);