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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 4477DC43441 for ; Fri, 9 Nov 2018 09:28:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0285B20840 for ; Fri, 9 Nov 2018 09:28:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="lQ4FzepY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0285B20840 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728090AbeKITH5 (ORCPT ); Fri, 9 Nov 2018 14:07:57 -0500 Received: from mail-lj1-f195.google.com ([209.85.208.195]:40853 "EHLO mail-lj1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727942AbeKITH5 (ORCPT ); Fri, 9 Nov 2018 14:07:57 -0500 Received: by mail-lj1-f195.google.com with SMTP id t22-v6so994938lji.7 for ; Fri, 09 Nov 2018 01:28:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=5b8nJovLJk9gu6KlVz8k5MUqM8YfcLM9odog2FYHi4c=; b=lQ4FzepYFSX8plHgHKgoKElIqpLUAIxpn444wSLXFrqzVd8Iq3C8+UhaSZgM+3/R+4 jjnA8cDAJkUgPouOhzTF2GyQLA9X4E/Y+scScef6WvnKooHbrrIzsFDJwyPkfXfkzjvE xQc8d9yOS2croAO4GlhV0G+LP0K/+b6onX/1ejZv4v1iIxQIITdhZyVZ2ZEODqUkwoDq 0Ze/VSsC9bm+gy5k5ORl8qy/G+3eIHsyfBAcATc0Y7WBOIcvlDPnDYhsjilEsIOfIRa4 J+mXpDDdnO/WBmjGC+g9x91FifPFQtvFdeBZ6ugvXXfaG+83gttYDtff2gD56CeB27kx CMiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=5b8nJovLJk9gu6KlVz8k5MUqM8YfcLM9odog2FYHi4c=; b=mprefJzDuzkLheasBNMHh+A1Wu34D7jAFFbEpUg/4IB54dU/AuzekSbdlTR18G8JgA H3SUuChgRsKrTX88OcXTxrhjH9glBBYhJJNpwIv+9T0hoX2Gyxdko+utfkQ5/LOZBpmp OvN3MCSbbtuDSB4/2kED5pr5LRtzhWhFQ7RVKeLHgDe9GrAPbXRzB/zhMQq235V6BtRu jAD4ETV8PFO1F0t50HFNrM3kTFadZB0oj/HbXDlOr/GxIMzcz5GlpKJSHAoVTg4AFJTN leujeD71vugzOtPnlRigHFtj98rmEA1N5suxZo0kxBMUXiw1W/177n0d3MruvOMPwXWm wcyQ== X-Gm-Message-State: AGRZ1gJgCZRBxU3xyQod9ulKSuInWIrVI2C5yLe3fuidlWOXgbh0kfCX q8hO3veUjZTMwvH5XYygwJs= X-Google-Smtp-Source: AJdET5deP/im00O26vQrkI33m8Dad8uVHiMv3c/6SNNaEUZg4XCPJnmvI95KMX3NtWOLxs+YkiEE6A== X-Received: by 2002:a2e:9819:: with SMTP id a25-v6mr5545068ljj.6.1541755692636; Fri, 09 Nov 2018 01:28:12 -0800 (PST) Received: from uranus.localdomain ([5.18.102.224]) by smtp.gmail.com with ESMTPSA id g15sm1124884lfb.1.2018.11.09.01.28.11 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 09 Nov 2018 01:28:11 -0800 (PST) Received: by uranus.localdomain (Postfix, from userid 1000) id 0F3274607EF; Fri, 9 Nov 2018 12:28:11 +0300 (MSK) Date: Fri, 9 Nov 2018 12:28:11 +0300 From: Cyrill Gorcunov To: Thomas Gleixner Cc: LKML , Andrey Vagin , Peter Zijlstra , Ingo Molnar Subject: Re: [PATCH] posix-timers: Use array safe helper when fetching notification symbolic name Message-ID: <20181109092810.GF13195@uranus.lan> References: <20181101182722.GA2869@uranus.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 09, 2018 at 10:18:25AM +0100, Thomas Gleixner wrote: > > + nidx = array_index_nospec(notify & ~SIGEV_THREAD_ID, ARRAY_SIZE(nstr)); > > I completely understand your intention, but this is misleading. The above > is really not a speculation gadget. > > I'd rather do an open coded check here and fail the thing instead of > printing wrong information: > > nidx = timer->it_sigev_notify & ~SIGEV_THREAD_ID; > if (nidx >= ARRAY_SIZE(nstr)) > return -EINVAL; Yes, I thought about such approach and did the similar code in first place, then I dropped it because didn't want additional "if"s here (your fix in the former commit already does all verification needed). But thinking more I agree: this code is not time critical and spending a few cycles won't hurt much. Will update, thanks Thomas!