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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 09DAEC433EF for ; Thu, 20 Jan 2022 03:49:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=C5jxgBFcv9VMvQgu52nQbyeFMD1EE4bzWmknJvQp3Yk=; b=BTcpPeLdkBbJoJ cOMvGPn2PELqug0T7luJ85JJnbEVocl+jyw3rthsNXcLfj4Wst0nUMKelFq+ylOzZDwbBYKaB4Qdu BWlEQI+ChyZQl0h31Fn4+NS70TEXtnTvFbT9l34EH/jKdHFr8FnlPCzxlFJg0dWYYLr8YkYL+e5nT XBoyCxT5JtVKC3lGe3UKs+6khE4GvkUOcnP+3JyQX+kERHklKO13ZnISR3mN9GounycVXoYLaaMdE TXtpNPq+c3WMeMU/aO55SJrwYMM/7I8cL09MC7h2QjpeHO21t6glKvX/R7985kZQ8/F01eLa1w8Pj 14PYNJpv24qkKRAzuxZw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nAORu-008Z0F-Km; Thu, 20 Jan 2022 03:49:22 +0000 Received: from mail-lf1-x133.google.com ([2a00:1450:4864:20::133]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nAORi-008YxC-2y for linux-mediatek@lists.infradead.org; Thu, 20 Jan 2022 03:49:11 +0000 Received: by mail-lf1-x133.google.com with SMTP id x11so16652954lfa.2 for ; Wed, 19 Jan 2022 19:49:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=AZnU5cEeFyaFBnpj/0CbEtA8JHuWrnQecXMIYCnzB/o=; b=ErV1kJfadCu1b5wgD6aEviZCSAk41KIjnGh8WYn8aHbrfBmz/Z03LAGBXFW2rQaPAJ 8nUEBpkWeomoODmY334NhCZOU+o0EljJbg8u2iyiFqhQzZA+efnPNwuXwUbmf0s5v/T1 kCYeVe9Uk4rKeiAhQV0qJH3LNcIRAZLLfIB4l+8HBTpN2EbhE7OMo9MsZ1jJFtNumTI7 6nq4zktXZrLgMTkM/3rhi6H2v1j+XohmCPmuRZ67scdSpSHYsD2JZXkUmKHOEB9cL3zx lOz0lnwWIRRBoK8mzCl56IReSHCns1DzoysZ5ToPrtmXJlo7ywMjgvALaTMfHs/M01U3 VAsQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=AZnU5cEeFyaFBnpj/0CbEtA8JHuWrnQecXMIYCnzB/o=; b=SaP1N/1tMND60WqsmdExj8BVmnqPJSVtkIkZZwQ67rwF/2m7jcdutdINmHdApMGZ8d zW+0ZpbN3xzk2dGV2hIznYCgbgSIXVRF4UCfX6oKC1aMvigZ1ogqzCKyYNLJyCdTeElo Tn0C8MkTQyxxkTl0CJDf9r67axd9xwfthcF1RAxgKqOxWxlH+jQ5tG63wnCeY+xQNLWH 1zdYtpACUzyqDcPI/k7ha18LkpYEWmyep0D4cq9OI1mGv2q+KItlR3z/Gx0qkBkCTEaW BtPwT6yuJFqtkneYSv/NR01osWjiHNQZa6Ccr7RzcjLmMx+LS4+39efjWf7sIhY/S1v4 zfCA== X-Gm-Message-State: AOAM530lbcypwKqNYbqGqz4+Uo2HPMrTD4qHzDWCVpXJtIIRYPFjZkM/ 81ZdGypAqRXPks5C55Alo6aH1d3usJB4IMvH0usdyA== X-Google-Smtp-Source: ABdhPJx0/Bt4Fv7Zhtxsw2WH0QARsie3jQTiwGG/ZBJTXsXxHRBXcquj3uP0/ZLAIBtBfzPMkNDAYvLD72ukCtWU1g8= X-Received: by 2002:a05:6512:3e1f:: with SMTP id i31mr25221311lfv.661.1642650547311; Wed, 19 Jan 2022 19:49:07 -0800 (PST) MIME-Version: 1.0 References: <20220120033450.90164-1-guangming.cao@mediatek.com> In-Reply-To: <20220120033450.90164-1-guangming.cao@mediatek.com> From: John Stultz Date: Wed, 19 Jan 2022 19:48:55 -0800 Message-ID: Subject: Re: [PATCH v4] dma-buf: system_heap: Add a size check for allocation To: guangming.cao@mediatek.com Cc: benjamin.gaignard@linaro.org, bo.song@mediatek.com, christian.koenig@amd.com, dri-devel@lists.freedesktop.org, jianjiao.zeng@mediatek.com, labbott@redhat.com, libo.kang@mediatek.com, linaro-mm-sig@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-mediatek@lists.infradead.org, lmark@codeaurora.org, matthias.bgg@gmail.com, michael.j.ruhl@intel.com, mingyuan.ma@mediatek.com, sumit.semwal@linaro.org, wsd_upstream@mediatek.com, yf.wang@mediatek.com, caoguangming34@gmail.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220119_194910_139451_96CC0E7C X-CRM114-Status: GOOD ( 18.83 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Wed, Jan 19, 2022 at 7:34 PM wrote: > > From: Guangming > > Add a size check for allocation since the allocation size should be > always less than the total DRAM size on system heap. > And it can prevent consuming too much time for invalid allocations. > > Signed-off-by: Guangming > --- > drivers/dma-buf/heaps/system_heap.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c > index 23a7e74ef966..bd6f255620e2 100644 > --- a/drivers/dma-buf/heaps/system_heap.c > +++ b/drivers/dma-buf/heaps/system_heap.c > @@ -347,6 +347,13 @@ static struct dma_buf *system_heap_allocate(struct dma_heap *heap, > struct page *page, *tmp_page; > int i, ret = -ENOMEM; > > + /* > + * Size check. The "len" should be less than totalram since system_heap > + * memory is comes from system. Adding check here can prevent consuming > + * too much time for invalid allocations. > + */ > + if (len >> PAGE_SHIFT > totalram_pages()) > + return -EINVAL; Thanks so much for revising and sending this along! It looks good to me. Acked-by: John Stultz thanks again -john _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek