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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2121C433EF for ; Fri, 12 Nov 2021 19:13:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8244960F0F for ; Fri, 12 Nov 2021 19:13:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235610AbhKLTQ1 (ORCPT ); Fri, 12 Nov 2021 14:16:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235379AbhKLTQ0 (ORCPT ); Fri, 12 Nov 2021 14:16:26 -0500 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A62CC061766 for ; Fri, 12 Nov 2021 11:13:35 -0800 (PST) Received: by mail-pg1-x54a.google.com with SMTP id z19-20020a630a53000000b002dc2f4542faso5305206pgk.13 for ; Fri, 12 Nov 2021 11:13:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:cc; bh=GsIi8/iqtr2GLgOD7vsfMp3NlXKV3TgHKavw0IFPKpY=; b=gt7k/aSehR6cQr0L3Jzrt9q7UFuIliY5b0NVuQY/JpWzn+348526bQv7ipD5Ast66n WaqLA8xmZ06AAntCyondqeJwzKAbruZQ+S8xsLRDSc58o7KLPlIqFLB6zgm03lhSjghj uo9F2keim+n85vNmhojyW1G109o9zeFxOgL/JSEmQGysXeyW269NHIszvnl55ajrq7DD vvzaPi8lqIR//koy8Efi4WdQ16mqo50hxlDvPqJAUOGcuIpwI2grylD9ti45kf5fxj4V BwNevQH0mK6mBKdq8rO0Lwjbi+4/V/vNuYi9PvNLm+Jy7AY0UkJvMXfVhLCx4UVkUOEQ OPng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:cc; bh=GsIi8/iqtr2GLgOD7vsfMp3NlXKV3TgHKavw0IFPKpY=; b=PhL0MvfqzvQVTaK40FtP3bcCivBt6livCIP439h6/76/D5cWHYPjasKVEgnCq/8OR5 jVMxNTJIYCwREEs8so0LRmwqBwzhPeJkow0iOSjpp8446a+9poGDzKywWIQXvfcAbFYd A/VVssQgrfeXwpT6ieLqEPijVmF7QHddUhqOAYMS37YxFOLWE1M3i9UaIPX+22QQGv+p RE6QinwZNcNsgp3aEFlZ78Q2O3T8HFF0c+LR3O2P5DDtaZHJxG28Txq01S3LeZ4Qit8x NLEJ2cPUNpi8q9FgtqBcd7uuc0OlZx8jxtIRaQjyDji7+lWsb7BWQZXZgEXHlubzjJ/A f6/w== X-Gm-Message-State: AOAM531qG4wuedqz53fYmW04rDGUJaLRjDVYtNjkn5bgTXZtBn8vv+Fb RsCqGTrmURccwVgimTIxW8NRwF8ZhtIR3jLuHA== X-Google-Smtp-Source: ABdhPJzYh+LCMezXcM7CyllvNk7f0e4nKS6rGcYs6E6xpHxga3UiQLpCIUS3W+BAnuOP8Al6JRqyNnWj/64XDIm53Q== X-Received: from kaleshsingh.mtv.corp.google.com ([2620:15c:211:200:b3bc:434c:ee52:f320]) (user=kaleshsingh job=sendgmr) by 2002:a17:90a:8a82:: with SMTP id x2mr20217933pjn.187.1636744414929; Fri, 12 Nov 2021 11:13:34 -0800 (PST) Date: Fri, 12 Nov 2021 11:13:24 -0800 Message-Id: <20211112191324.1302505-1-kaleshsingh@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.34.0.rc1.387.gb447b232ab-goog Subject: [PATCH] tracing/histogram: Fix check for missing operands in an expression From: Kalesh Singh Cc: kernel-team@android.com, rostedt@goodmis.org, mhiramat@kernel.org, zanussi@kernel.org, Kalesh Singh , Dan Carpenter , Ingo Molnar , Namhyung Kim , linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If a binary operation is detected while parsing an expression string, the operand strings are deduced by splitting the experssion string at the position of the detected binary operator. Both operand strings are sub-strings (can be empty string) of the expression string but will never be NULL. Currently a NULL check is used for missing operands, fix this by checking for empty strings instead. Signed-off-by: Kalesh Singh Fixes: 9710b2f341a0 ("tracing: Fix operator precedence for hist triggers expression") Reported-by: Dan Carpenter --- kernel/trace/trace_events_hist.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 0abc9a413b4d..328b1f83a3c8 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -2580,7 +2580,8 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, operand1_str = str; str = sep+1; - if (!operand1_str || !str) + /* Binary operator requires both operands */ + if (*operand1_str == '\0' || *str == '\0') goto free; operand_flags = 0; base-commit: 5833291ab6de9c3e2374336b51c814e515e8f3a5 -- 2.34.0.rc1.387.gb447b232ab-goog