From mboxrd@z Thu Jan 1 00:00:00 1970 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=-6.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,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 487A5C433DF for ; Sat, 13 Jun 2020 15:58:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2556C20789 for ; Sat, 13 Jun 2020 15:58:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="l5X5yT12" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726608AbgFMP6W (ORCPT ); Sat, 13 Jun 2020 11:58:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726544AbgFMP6K (ORCPT ); Sat, 13 Jun 2020 11:58:10 -0400 Received: from mail-ot1-x341.google.com (mail-ot1-x341.google.com [IPv6:2607:f8b0:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3EDE0C03E96F for ; Sat, 13 Jun 2020 08:58:08 -0700 (PDT) Received: by mail-ot1-x341.google.com with SMTP id v13so9756967otp.4 for ; Sat, 13 Jun 2020 08:58:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=yGK4Co7NDboyjza4qRh2rluizajI/4ObcvQZ/gCqlA4=; b=l5X5yT12ssNv2xKvw8g3JqKWwmPysYm7vAtMWsJG4UumwH8R2g1fappn53oAHdz95e R8iGsuiaXz3tnAVMHM3ntaifzEaOyEYtWF70MAW8wj3X3eC1Zj2DFbHfq+TOT9slN7iO mJd1wZpl4xS7jSeGVi7LI0T/Cw0GkPUtuaYSx53dpEspilUiUiGYob6UiKHucKs+rzIS 9m6PPgkHfck1eijWsK+1qiMB0n6ADOkh2FIz77w7CJnVJx8z70dl4Tu9sATuTvgN90iz 7dM6jYfaxd/5qf7zeqHSEDTVxpgXDRZGfgiZLCvdxU2tbLDTqBdk4+NDrxLYJdY62bcv CFEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=yGK4Co7NDboyjza4qRh2rluizajI/4ObcvQZ/gCqlA4=; b=WS0CTNUPUizbHswG/o9K3oRkRW0q4NflgHjk9DRzgpKTI+HVKEgPCkTnEDyD+A/ne8 rndQfC1rIwkaat3T6jabTnU7Yj8lBRzffa5+Co4hrIdfNPt59HYHcFZmcZARUN8jLZsV 5Z7fIBpUYxdeWPaA9FBOM2s7VMgCG/jA4ENc+QceoJ+YTRiVwunkpzeL+i62xEwyG/wu dtAq9SMTFGD3OZ6irQzBJQ2N7WmX7mlwZczPfbeVt245tZXn5/M9mRlnpS3V49YjRKkr uXO41p9RQHsirm9B3j2j5KZXcvUp5OdD7v7ZahlTD+sgQ/amenx92fDmAAJ6Y2p036QS YNSg== X-Gm-Message-State: AOAM531nKPbh5wylrDPY8TDMlAtnOKpJvZ+G0GS1GdP0SI6aa7pPfXMC VkOjOV/KmY66t5Rm/rXEiQs= X-Google-Smtp-Source: ABdhPJwTgAq76eJRmdksQgH/+D7eHxhoFXN31VaLR7x99kGjXWQasEaqg9r1u22tiuxZkr00TtP1GA== X-Received: by 2002:a05:6830:1bca:: with SMTP id v10mr14419789ota.109.1592063886536; Sat, 13 Jun 2020 08:58:06 -0700 (PDT) Received: from frodo.hsd1.co.comcast.net ([2601:284:8204:6ba0::aaac]) by smtp.googlemail.com with ESMTPSA id 53sm2105565otv.22.2020.06.13.08.58.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 13 Jun 2020 08:58:05 -0700 (PDT) From: Jim Cromie To: jbaron@akamai.com, linux-kernel@vger.kernel.org, akpm@linuxfoundation.org, gregkh@linuxfoundation.org Cc: linux@rasmusvillemoes.dk, Jim Cromie Subject: [PATCH v2 07/24] dyndbg: fix a BUG_ON in ddebug_describe_flags Date: Sat, 13 Jun 2020 09:57:21 -0600 Message-Id: <20200613155738.2249399-8-jim.cromie@gmail.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200613155738.2249399-1-jim.cromie@gmail.com> References: <20200613155738.2249399-1-jim.cromie@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 the flags parameter, and instead de-ref the flags struct in the caller; this makes the function reusable (soon) where flags are unpacked. --- lib/dynamic_debug.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 9b2445507988..aaace13d7536 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 vnpr_info(lvl, fmt, ...) \ @@ -141,13 +141,13 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg) * logs the changes. Takes ddebug_lock. */ static int ddebug_change(const struct ddebug_query *query, - unsigned int flags, unsigned int mask) + unsigned int pflags, unsigned int mask) { int i; struct ddebug_table *dt; unsigned int newflags; unsigned int nfound = 0; - char flagbuf[10]; + struct flagsbuf flags; /* search for matching ddebugs */ mutex_lock(&ddebug_lock); @@ -190,22 +190,21 @@ static int ddebug_change(const struct ddebug_query *query, nfound++; - newflags = (dp->flags & mask) | flags; + newflags = (dp->flags & mask) | pflags; if (newflags == dp->flags) continue; #ifdef CONFIG_JUMP_LABEL if (dp->flags & _DPRINTK_FLAGS_PRINT) { - if (!(flags & _DPRINTK_FLAGS_PRINT)) + if (!(pflags & _DPRINTK_FLAGS_PRINT)) static_branch_disable(&dp->key.dd_key_true); - } else if (flags & _DPRINTK_FLAGS_PRINT) + } else if (pflags & _DPRINTK_FLAGS_PRINT) static_branch_enable(&dp->key.dd_key_true); #endif dp->flags = newflags; v2pr_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, &flags)); } } mutex_unlock(&ddebug_lock); @@ -814,7 +813,7 @@ 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; if (p == SEQ_START_TOKEN) { seq_puts(m, @@ -825,7 +824,7 @@ 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"); -- 2.26.2