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=-8.3 required=3.0 tests=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_SANE_1 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 5151BC3A5A3 for ; Tue, 27 Aug 2019 18:42:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 252162186A for ; Tue, 27 Aug 2019 18:42:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="Tg3wAqzK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730865AbfH0Sl7 (ORCPT ); Tue, 27 Aug 2019 14:41:59 -0400 Received: from mail-qt1-f193.google.com ([209.85.160.193]:44006 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730237AbfH0Sl6 (ORCPT ); Tue, 27 Aug 2019 14:41:58 -0400 Received: by mail-qt1-f193.google.com with SMTP id b11so28054qtp.10 for ; Tue, 27 Aug 2019 11:41:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=9ceAN/Yoez35TeAjbDhFK5DksMbw1eL2zoww/c7DDSE=; b=Tg3wAqzKDb2Nvtp5xnTJu8Zd7Xoskps6KbP7KGSG2mXkHL1YpVlpacJxibryLDlNJw 179cDfjV75KnOnbO786z8kq561zwavu/nufenfX6VMltb+S29UuroexvGBTlW43jXQmu BnfnPJVVYk2s3RHioNaSV2iGEh7jX3UBGoPb1YLczXEMrlSdBRwoauSdVh1dnk3odz81 5DTC0TRiSs3uSv6gH+zLxmF3Fs8g9ISCjSxPwwihfMHKeWeF5bYqA+q9TtOOx2nNKZ8P Zp8VHkM7RZiKWOrFRQbrnX0L3PbEWZuZHj7c02SuCN1iqneJHz/alYfeQVVF1tfTWxVj JRYw== 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=9ceAN/Yoez35TeAjbDhFK5DksMbw1eL2zoww/c7DDSE=; b=KhM0jR2ubAr06tJc6+ekbrRaQEzY4jmFKSlXW+OO9M5lau4Z7/PSp3u8vt83H0WQS/ r8s9l9N9eOMTw+ppPYziI4lvfhIIw4bC3abf9fFgH8YvEJe//nLCgNFBYdaEGzRB+u/S L771xZrm5qfDx+MIGPHMKV0n6vcxWgFGQCId3gut9db4tknPrsx7MPd9/TIdPPmkcQd2 5w+j24urbHBrPvzr84n7Q8TD6n/yaPIjk/VFeLzk0jRiJWJp1Ry6v8sdmfJwd1yOUzMM 5pp9YXWBHur6nwtBUL8VZgSLLtsWn7YwGDSWILjyG4VbTsJ2z9kDLQGUBW8ZKwkLN5Fz QBbA== X-Gm-Message-State: APjAAAU8RgV/rcVI93CrvekoQ+937ce/Dgyqr5lAG3GRJNcJ93Erd7Wy qDLxffeNw3SE1tunGv6d71m+ZA== X-Google-Smtp-Source: APXvYqxGsIEH37K7EHHZpDcbxKJ2Zt/WeLY+aot3NzZQz1/QF/DaeFShLNUpqkv0bACqFBQq4QCy2g== X-Received: by 2002:ac8:23cf:: with SMTP id r15mr242835qtr.97.1566931317969; Tue, 27 Aug 2019 11:41:57 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-142-167-216-168.dhcp-dynamic.fibreop.ns.bellaliant.net. [142.167.216.168]) by smtp.gmail.com with ESMTPSA id x28sm9926373qtk.8.2019.08.27.11.41.57 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 27 Aug 2019 11:41:57 -0700 (PDT) Received: from jgg by mlx.ziepe.ca with local (Exim 4.90_1) (envelope-from ) id 1i2gPl-0006d2-1c; Tue, 27 Aug 2019 15:41:57 -0300 Date: Tue, 27 Aug 2019 15:41:57 -0300 From: Jason Gunthorpe To: Ralph Campbell Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, =?utf-8?B?SsOpcsO0bWU=?= Glisse , Andrew Morton , Christoph Hellwig Subject: Re: [PATCH 2/2] mm/hmm: hmm_range_fault() infinite loop Message-ID: <20190827184157.GA24929@ziepe.ca> References: <20190823221753.2514-1-rcampbell@nvidia.com> <20190823221753.2514-3-rcampbell@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190823221753.2514-3-rcampbell@nvidia.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 23, 2019 at 03:17:53PM -0700, Ralph Campbell wrote: > Signed-off-by: Ralph Campbell > mm/hmm.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/hmm.c b/mm/hmm.c > index 29371485fe94..4882b83aeccb 100644 > +++ b/mm/hmm.c > @@ -292,6 +292,9 @@ static int hmm_vma_walk_hole_(unsigned long addr, unsigned long end, > hmm_vma_walk->last = addr; > i = (addr - range->start) >> PAGE_SHIFT; > > + if (write_fault && walk->vma && !(walk->vma->vm_flags & VM_WRITE)) > + return -EPERM; Can walk->vma be NULL here? hmm_vma_do_fault() touches it unconditionally. Jason