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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 74319C43603 for ; Mon, 9 Dec 2019 17:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3CF91207FD for ; Mon, 9 Dec 2019 17:29:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="PKOR9wiZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726495AbfLIR36 (ORCPT ); Mon, 9 Dec 2019 12:29:58 -0500 Received: from mail-ot1-f67.google.com ([209.85.210.67]:36750 "EHLO mail-ot1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726230AbfLIR36 (ORCPT ); Mon, 9 Dec 2019 12:29:58 -0500 Received: by mail-ot1-f67.google.com with SMTP id i4so12920211otr.3 for ; Mon, 09 Dec 2019 09:29:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Dcgdz44q2GCvADR7a/LkLs9ynpEQVQ92g/NDbUJ9ByU=; b=PKOR9wiZIB18b/51jkUG/wXIFefbTZbsIoGHXMC3Wa+HrxHrvmOkKTzDzw+sXBVIlk WIeKjcijz8em6sM32WwxvXsG6eJYecW1+Vr8KQUTsTvwAezJa3uxBtNCwH0rvj3Hax2z 2OapWK7fvk/DbmGvycFL+e8p61RygSe62KIF8= 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=Dcgdz44q2GCvADR7a/LkLs9ynpEQVQ92g/NDbUJ9ByU=; b=p9OcnyMhCpNUSJU/ZGVlUVkkK/o0LjXxemy4Ah/aiq1qMhjWcg7yylrN6r1958wm3h 7VWEJuIeEwF/JBQ2IP/WR88vnT5FhvzApQAxaSKOupVVntr8y822Wp7bIRtvbK7MGyrt YZvycmOeVNyH2u1XJlzhOww7T1ljiNauLsZ8rY+ETleJNNKBZXkH39OWklywQeazga01 ivt0b1SGGtBgXmtiBSwDFvewNdHwVNpEi6n3ryz1AHl5lQQviY0Jp0AbLmVISIpJNJYV lZS3DKx9Ji9dYGkOUcl1HPi9u1VgY4zDrQKAXsXno0c8JY9JztuObq8jlwqtmEeLkwkj VPOg== X-Gm-Message-State: APjAAAWJK5GkhInLtMSMxVeA8/9u2mg9f1ldDse+2qgM0TSVdM4KPkHr z/KPJaVrKR2E0K4BJdJWNqQa0OqU69wJSNo/ZY+uwShY X-Google-Smtp-Source: APXvYqz4AY07BzHgic5er69wv22sNZkWuNoimJ4dj0xiy8faF2rZTCRbn2c2dvhbKtnKoCqZ27uqaKVyNe2AUdEl/0o= X-Received: by 2002:a05:6830:1e75:: with SMTP id m21mr21646882otr.36.1575912597048; Mon, 09 Dec 2019 09:29:57 -0800 (PST) MIME-Version: 1.0 References: <201912080836.xB88amHd015549@sdf.org> In-Reply-To: <201912080836.xB88amHd015549@sdf.org> From: Michael Chan Date: Mon, 9 Dec 2019 09:29:46 -0800 Message-ID: Subject: Re: [RFC PATCH 2/4] b44: Fix off-by-one error in acceptable address range To: George Spelvin Cc: Netdev , Hauke Mehrtens Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, Dec 8, 2019 at 12:36 AM George Spelvin wrote: > > The requirement is dma_addr + size <= 0x40000000, not 0x3fffffff. > > In a logically separate but overlapping change, this patch also > rearranges the logic for detecting failures to use a goto rather > than testing dma_mapping_error() twice. The latter is expensive if > CONFIG_DMA_API_DEBUG is set, but also for bug-proofing reasons I try to > avoid having the same condition in two places that must be kept in sync. > > Signed-off-by: George Spelvin > --- > drivers/net/ethernet/broadcom/b44.c | 42 ++++++++++++++++------------- > 1 file changed, 24 insertions(+), 18 deletions(-) > > diff --git a/drivers/net/ethernet/broadcom/b44.c b/drivers/net/ethernet/broadcom/b44.c > index 394671230c1c..e540d5646aef 100644 > --- a/drivers/net/ethernet/broadcom/b44.c > +++ b/drivers/net/ethernet/broadcom/b44.c > @@ -680,12 +680,13 @@ static int b44_alloc_rx_skb(struct b44 *bp, int src_idx, u32 dest_idx_unmasked) > > /* Hardware bug work-around, the chip is unable to do PCI DMA > to/from anything above 1GB :-( */ > - if (dma_mapping_error(bp->sdev->dma_dev, mapping) || > - mapping + RX_PKT_BUF_SZ > DMA_BIT_MASK(30)) { > + if (dma_mapping_error(bp->sdev->dma_dev, mapping)) > + goto workaround; > + if (mapping + RX_PKT_BUF_SZ > DMA_BIT_MASK(30)+1) { The patchset looks ok to me. The only minor suggestion is to define this (DMA_BIT_MASK(30) + 1) as B44_DMA_ADDR_LIMIT or something like that so you don't have to repeat it so many times. Thanks.