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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 63819C55189 for ; Wed, 22 Apr 2020 22:05:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E6A021655 for ; Wed, 22 Apr 2020 22:05:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ayF+6gIs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726614AbgDVWFC (ORCPT ); Wed, 22 Apr 2020 18:05:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726577AbgDVWE7 (ORCPT ); Wed, 22 Apr 2020 18:04:59 -0400 Received: from mail-pj1-x104a.google.com (mail-pj1-x104a.google.com [IPv6:2607:f8b0:4864:20::104a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 013D7C03C1A9 for ; Wed, 22 Apr 2020 15:04:59 -0700 (PDT) Received: by mail-pj1-x104a.google.com with SMTP id i9so2946952pjs.4 for ; Wed, 22 Apr 2020 15:04:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=8jb1TKGtNOzFJaH+zGkIw1wrutaG9liyHI83TX/6kqM=; b=ayF+6gIswEMHPNht9DRwjemw9VXGHQmmH+WQZwyrxUEVDiQGMQTxhFqqbQL3CAJ3hS g8b6n8lWjMwG0kvdSZWrlldhI5uIHsWQ33Be8do2mBbMYsLMkpeuboO6xdkybJBJGgWE rLlW6aW2sMA/ORzubO35PxvarD4+HB2KvIe8+2QsPRJ4tAKWjX5mvP1jx7gxlGdtbzaF Fwx7nsHtDNTaSNH+iNDDEc933apf+WIeexxAT1KDtoauG9SSpgNCi62GDxS95xL2tAIz ghtuSFBu4ih4TbQS0590sbxvwdINGt7Pvk32Wj3Vms6m6ZcYk+D8J2+5d/QDj6nQlrAo r0tA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=8jb1TKGtNOzFJaH+zGkIw1wrutaG9liyHI83TX/6kqM=; b=lZuJ0VD6B7clALstQkzKhdh/J/ckqBUkQW/8kmNHW2tSjA3z+GPw9kaYHCQZeuTmWK fHdbNsbR9nwJP1rHA8Wv54nfP//A+zcK78QthKYoqnqaRydaG9GBXxwxQDFFkckHwND0 gEjdArn41ajD4hlIJXKHf0ZzQIMhVPJ1ihl6ewtNrweMOiROEHDARclJ5DyboE6To5Wt H3OUvLMWTUTB+yhw+FzXzzF6I6DqbXiYkzIJdZXogmU1P8XD3ANf71iZemjd5pQ+mbVW B2TJ4SMaHYVU0oC9nDp2Q9TzevvTahhnBfByuo8HkQUQa2losqUg+2SdlQQLdvj6pSj9 oRYQ== X-Gm-Message-State: AGi0Pua2twMk2TlnDxoWUFJXxZ5WIyzauIoFSukQSXnsnQQBxS41RWaN 8C2+BQGUZ3WBCslDizKCbHNUxakG5QyI X-Google-Smtp-Source: APiQypIcRniLx2dAK6np1iyd92nSVT7y5C8wddV7Z01zuWs3KW+xK/j6SSGfKeLeZegOBRgqZMDZ77vd28P8 X-Received: by 2002:a17:90a:2f64:: with SMTP id s91mr973455pjd.30.1587593098406; Wed, 22 Apr 2020 15:04:58 -0700 (PDT) Date: Wed, 22 Apr 2020 15:04:29 -0700 In-Reply-To: <20200422220430.254014-1-irogers@google.com> Message-Id: <20200422220430.254014-11-irogers@google.com> Mime-Version: 1.0 References: <20200422220430.254014-1-irogers@google.com> X-Mailer: git-send-email 2.26.2.303.gf8c07b1a785-goog Subject: [PATCH v2 10/11] perf expr: print a debug message for division by zero From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Kan Liang , Andi Kleen , Haiyan Song , Jin Yao , Song Liu , Ravi Bangoria , John Garry , Leo Yan , Adrian Hunter , Paul Clarke , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Cc: Stephane Eranian , Ian Rogers Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If an expression yields 0 and is then divided-by/modulus-by then the parsing aborts. Add a debug error message to better enable debugging when this happens. Signed-off-by: Ian Rogers --- tools/perf/util/expr.y | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y index 54260094b947..21e82a1e11a2 100644 --- a/tools/perf/util/expr.y +++ b/tools/perf/util/expr.y @@ -103,8 +103,18 @@ expr: NUMBER | expr '+' expr { $$ = $1 + $3; } | expr '-' expr { $$ = $1 - $3; } | expr '*' expr { $$ = $1 * $3; } - | expr '/' expr { if ($3 == 0) YYABORT; $$ = $1 / $3; } - | expr '%' expr { if ((long)$3 == 0) YYABORT; $$ = (long)$1 % (long)$3; } + | expr '/' expr { if ($3 == 0) { + pr_debug("division by zero\n"); + YYABORT; + } + $$ = $1 / $3; + } + | expr '%' expr { if ((long)$3 == 0) { + pr_debug("division by zero\n"); + YYABORT; + } + $$ = (long)$1 % (long)$3; + } | '-' expr %prec NEG { $$ = -$2; } | '(' if_expr ')' { $$ = $2; } | MIN '(' expr ',' expr ')' { $$ = $3 < $5 ? $3 : $5; } -- 2.26.2.303.gf8c07b1a785-goog