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=-3.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 9A224C433E3 for ; Thu, 21 May 2020 22:10:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 775A0207D3 for ; Thu, 21 May 2020 22:10:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="rvtv2nZM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730688AbgEUWK4 (ORCPT ); Thu, 21 May 2020 18:10:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728701AbgEUWKz (ORCPT ); Thu, 21 May 2020 18:10:55 -0400 Received: from mail-qk1-x743.google.com (mail-qk1-x743.google.com [IPv6:2607:f8b0:4864:20::743]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69E23C061A0E; Thu, 21 May 2020 15:10:54 -0700 (PDT) Received: by mail-qk1-x743.google.com with SMTP id f13so8944784qkh.2; Thu, 21 May 2020 15:10:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=isMsZ2pUMyCVKxa9Y2mlyk5l3TCYNg/xt93/ki7P2xM=; b=rvtv2nZMjsCYj/CeRcxqSRzJYCvoWBWeEm/72+lnNyxa+Vdy9NkfFeD8cpeGY76yDk wfvMzNxbucIn7Hs+oWyf05qo9fHMcUsteanx5aU0XArHtMRRXJLuU721EUNgAES4ID8L 4BK22OGZzPIFuxQJNAXNMRKzin+VQSx6P4f7rTt5QxVcnbVdnbKLOB4xWP/9BUtlDCzG wxQKxlWDremxmA6nHO7Dnyr4bSR0bzQXoj8MWM7oqmmacFdDmArrPOzkdO2ojiT2NeXZ 3rF1QgvrXugmu2458C0loC8GmxZvMhABO4SKgIQSvB76sfSoth+Bvjqp6Btx4FaWlhSq MSyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=isMsZ2pUMyCVKxa9Y2mlyk5l3TCYNg/xt93/ki7P2xM=; b=FBptfPGUWDhzI8w9NoAiGfqiiSfE6M7fJjPj/rxL+umLgLcWDDiyVs8/v9wGhNbVAJ R4GqelqZxq5SWSEFWhPsasveFwsHtmZ7BzBWuWIRRfUO6x0HdNfTp6HmgT4zCep/9YDo HYtqGgcYqXICe4/Fgili/0M3FhyoSwMzFG3kmTXraDOtp/BFLBWsv+XYqN7P0jBITp38 1+6EsvEnhY9yJPYvpdXCbib0Q5knjbBE9gXX3QFWZJwx/m+yvy+f7jaem3GoImzYeLQq 39P4Ysmk/XeYJJr2vOC163tKIf7Yphy4VvCm+Kcsu0OQtjJp/u1SlsHYkA6do39+5iwk gYXA== X-Gm-Message-State: AOAM5324Oa27ravLh38tLiNdQMW1y5JxC8tVAi1JDLDw94HSp4AUxS49 2f1GkdaVcSxMLParkw2Jfhu4fZ8AkcJQfVXyAc0= X-Google-Smtp-Source: ABdhPJyXmTlK01x/mLueG4iMCV7LUGdCvFmE02/3ZxSTylcerxvuwFpzisGXHtk+V9iTqf6OpLYFCd1cU/qrM9V446Y= X-Received: by 2002:ae9:e713:: with SMTP id m19mr12160235qka.39.1590099053692; Thu, 21 May 2020 15:10:53 -0700 (PDT) MIME-Version: 1.0 References: <20200521152301.2587579-1-hch@lst.de> <20200521152301.2587579-14-hch@lst.de> In-Reply-To: <20200521152301.2587579-14-hch@lst.de> From: Andrii Nakryiko Date: Thu, 21 May 2020 15:10:42 -0700 Message-ID: Subject: Re: [PATCH 13/23] bpf: rework the compat kernel probe handling To: Christoph Hellwig Cc: x86@kernel.org, Alexei Starovoitov , Daniel Borkmann , Masami Hiramatsu , Linus Torvalds , Andrew Morton , linux-parisc@vger.kernel.org, linux-um@lists.infradead.org, Networking , bpf , linux-mm@kvack.org, open list Content-Type: text/plain; charset="UTF-8" Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Thu, May 21, 2020 at 8:26 AM Christoph Hellwig wrote: > > Instead of using the dangerous probe_kernel_read and strncpy_from_unsafe > helpers, rework the compat probes to check if an address is a kernel or > userspace one, and then use the low-level kernel or user probe helper > shared by the proper kernel and user probe helpers. This slightly > changes behavior as the compat probe on a user address doesn't check > the lockdown flags, just as the pure user probes do. > > Signed-off-by: Christoph Hellwig > --- Looks good, thanks. Acked-by: Andrii Nakryiko > kernel/trace/bpf_trace.c | 109 ++++++++++++++++++++++++--------------- > 1 file changed, 67 insertions(+), 42 deletions(-) > [...]