From patchwork Thu Aug 20 09:21:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 265753 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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 A1ACAC433E1 for ; Thu, 20 Aug 2020 10:04:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E3EC22CF7 for ; Thu, 20 Aug 2020 10:04:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597917857; bh=bKZyCJY5tcwU9+t7Ri2QDzZnhI/88fXqAczSnav0mCs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jV42UtnyhmEcCKOZlXMbWZphiJAmpGVNfOf7485Hy4Ul1asCilmFhfe56gQKfBkzL kV9rs3PBpHF8tS34SBTOFNOF+j4A/qsi9X+rPQ+aBgDUhotiXLvjTqtiGXE9qeA4nq t1VmAlYA+zy4WVtbhfE6MrwQ7uGGEB5zIk2jJ2vQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726873AbgHTKEI (ORCPT ); Thu, 20 Aug 2020 06:04:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:50864 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730424AbgHTKCG (ORCPT ); Thu, 20 Aug 2020 06:02:06 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C5E2C22BEB; Thu, 20 Aug 2020 10:02:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597917724; bh=bKZyCJY5tcwU9+t7Ri2QDzZnhI/88fXqAczSnav0mCs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VP6cQA9QvB4leoY92XUWA2KsC2QJj9Oen5cqagRpKjV4lXFaJI8WdpX8pLiEyipI8 Yk9oRZksBt2qGrcq4rjKoHKc3Ff+X2Y+BbOsLf8Zg9NflofXP2ItqYeYHh9246x0pn U+BFy4VKCBXqiLIn9qwS3za1zhhPYps34+GJr9E8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, jbaron@akamai.com, Jim Cromie , Sasha Levin Subject: [PATCH 4.9 104/212] dyndbg: fix a BUG_ON in ddebug_describe_flags Date: Thu, 20 Aug 2020 11:21:17 +0200 Message-Id: <20200820091607.600406573@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820091602.251285210@linuxfoundation.org> References: <20200820091602.251285210@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jim Cromie [ Upstream commit f678ce8cc3cb2ad29df75d8824c74f36398ba871 ] ddebug_describe_flags() currently fills a caller provided string buffer, after testing its size (also passed) in a BUG_ON. Fix this by replacing them with a known-big-enough string buffer wrapped in a struct, and passing that instead. Also simplify ddebug_describe_flags() flags parameter from a struct to a member in that struct, and hoist the member deref up to the caller. This makes the function reusable (soon) where flags are unpacked. Acked-by: Signed-off-by: Jim Cromie Link: https://lore.kernel.org/r/20200719231058.1586423-8-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- lib/dynamic_debug.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index c7c96bc7654af..91c451e0f4741 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -85,22 +85,22 @@ static struct { unsigned flag:8; char opt_char; } opt_array[] = { { _DPRINTK_FLAGS_NONE, '_' }, }; +struct flagsbuf { char buf[ARRAY_SIZE(opt_array)+1]; }; + /* format a string into buf[] which describes the _ddebug's flags */ -static char *ddebug_describe_flags(struct _ddebug *dp, char *buf, - size_t maxlen) +static char *ddebug_describe_flags(unsigned int flags, struct flagsbuf *fb) { - char *p = buf; + char *p = fb->buf; int i; - BUG_ON(maxlen < 6); for (i = 0; i < ARRAY_SIZE(opt_array); ++i) - if (dp->flags & opt_array[i].flag) + if (flags & opt_array[i].flag) *p++ = opt_array[i].opt_char; - if (p == buf) + if (p == fb->buf) *p++ = '_'; *p = '\0'; - return buf; + return fb->buf; } #define vpr_info(fmt, ...) \ @@ -142,7 +142,7 @@ static int ddebug_change(const struct ddebug_query *query, struct ddebug_table *dt; unsigned int newflags; unsigned int nfound = 0; - char flagbuf[10]; + struct flagsbuf fbuf; /* search for matching ddebugs */ mutex_lock(&ddebug_lock); @@ -199,8 +199,7 @@ static int ddebug_change(const struct ddebug_query *query, vpr_info("changed %s:%d [%s]%s =%s\n", trim_prefix(dp->filename), dp->lineno, dt->mod_name, dp->function, - ddebug_describe_flags(dp, flagbuf, - sizeof(flagbuf))); + ddebug_describe_flags(dp->flags, &fbuf)); } } mutex_unlock(&ddebug_lock); @@ -779,7 +778,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p) { struct ddebug_iter *iter = m->private; struct _ddebug *dp = p; - char flagsbuf[10]; + struct flagsbuf flags; vpr_info("called m=%p p=%p\n", m, p); @@ -792,7 +791,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p) seq_printf(m, "%s:%u [%s]%s =%s \"", trim_prefix(dp->filename), dp->lineno, iter->table->mod_name, dp->function, - ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf))); + ddebug_describe_flags(dp->flags, &flags)); seq_escape(m, dp->format, "\t\r\n\""); seq_puts(m, "\"\n");