From patchwork Mon Aug 17 15:11:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 265937 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=unavailable 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 BBAB5C433E3 for ; Mon, 17 Aug 2020 19:42:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9FDE120716 for ; Mon, 17 Aug 2020 19:42:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597693363; bh=Lgs+8vMftcfizsQZfbh2XLM+KHpVwJXQiyIHbgwXzJQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GiwRzSfKizytAF6liJ6DGsrfa74QjvFHGv5ljQyvn4MIxHgNpalhJ7gkCE3oa1PXZ yGBCQ43eo8WlVI3G7Nme5EhObqwxVYZEp895WCFgdwTwnCzlLs8rcZWvdaaiPcuBeO uovi0OfjLuLMqL2QvsgAYk0ymxQ5fdsDA8EAn4v0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729628AbgHQPYM (ORCPT ); Mon, 17 Aug 2020 11:24:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:53788 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729623AbgHQPYL (ORCPT ); Mon, 17 Aug 2020 11:24:11 -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 EAF5920729; Mon, 17 Aug 2020 15:24:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597677850; bh=Lgs+8vMftcfizsQZfbh2XLM+KHpVwJXQiyIHbgwXzJQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lUOuhhLH/aaauZG9DgS0/exKmfFSlRcWvmT8OIxvycvDTwdpFvce4IJn+dILq1ffQ amuNKEo3sEFdXdJgP3kSfzOngvYU9CdDj6rdgs8iyzWWSpuqxg5Hzk5jat/oCbM2r1 7f544UFsfvs47F+8geJYlrgAZs0Ou3UXvqvIcpNg= 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 5.8 131/464] dyndbg: fix a BUG_ON in ddebug_describe_flags Date: Mon, 17 Aug 2020 17:11:24 +0200 Message-Id: <20200817143840.088025996@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143833.737102804@linuxfoundation.org> References: <20200817143833.737102804@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 321437bbf87dd..98876a8255c7d 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -87,22 +87,22 @@ 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, ...) \ @@ -144,7 +144,7 @@ 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); @@ -201,8 +201,7 @@ 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); @@ -816,7 +815,7 @@ 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); @@ -829,7 +828,7 @@ 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");