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=-14.4 required=3.0 tests=DKIMWL_WL_MED,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_IN_DEF_DKIM_WL 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 4E854C32771 for ; Wed, 22 Jan 2020 23:56:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1BD18205C9 for ; Wed, 22 Jan 2020 23:56:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Ri0IcXw5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728760AbgAVX4H (ORCPT ); Wed, 22 Jan 2020 18:56:07 -0500 Received: from mail-pg1-f194.google.com ([209.85.215.194]:45098 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726054AbgAVX4H (ORCPT ); Wed, 22 Jan 2020 18:56:07 -0500 Received: by mail-pg1-f194.google.com with SMTP id b9so362222pgk.12 for ; Wed, 22 Jan 2020 15:56:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:subject:cc:to:in-reply-to:references:message-id :mime-version:content-transfer-encoding; bh=cCUsdj/fZYwNN192nrue22afyzRZAQtb0Bq+RK6T7n8=; b=Ri0IcXw57gZiaEwAVrFx7No5+7en+4TehQHRwWbKCEqldQbtMfnfW6EZuTtGgX5Cb3 Lm1a+PGl5BLXa1r+5rjTW5oHFJ0JVM0AgfndPlja0Ep8PEtTtzk6WVzuvKaqn7P87Gku wiEz3wygmiAFEk73UezHVlySvHjepgfqzgehaaRIjD0UifT3IWYxkfY49gobkruN+4gY CIt55fHrJjz1ugrqp/mCP8ZZDRZLePBXBo+Xm2NdUHgrh3AH40LGUue67Y8AVIWDuPhk b1qIKKZXY5Xl5I/2EzwU28A2gLoqXrwDWPwZdPJIVsVH5XLgO+tIj8+c9Tdth9J/D56f XmIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:subject:cc:to:in-reply-to:references :message-id:mime-version:content-transfer-encoding; bh=cCUsdj/fZYwNN192nrue22afyzRZAQtb0Bq+RK6T7n8=; b=htelS4YODjkX9a+gm7VMnsimibv5n20ADjQqrowRZa1kbU77cReAeM/JmV1x45JDDo 9TYWPLVa3GQdhGaXIhgEAPmpxfZPHjKQreuZGhpCiPVJysH23L40zuBJEBz3RF3vDmeh k41v1s2KacI4VQlrDqPppCMSZytRwUAifDlcb++Y6BW9xA5rZxTEuySDEONd81jfo5Yz 1Rzvp4i1pgjl7ludSiQ4l3RkYr7QYLi7xlSHOujOtrXfNR9HXY3T3TdBzurPgrqe9BeH 5bUl6MS6z/c3B9EkypDZnt0MLVKaY9XtI4zcE2jiWOiMwpYDWr4OPQsHjQetl3AXmW7F 8QTQ== X-Gm-Message-State: APjAAAXWp3VmIz246AaIsFDmMxJgpflNSQ6Hh9d7ATOGP0xh1hceBFv7 AcnblZL3EgNTBgvl7PPRAs8edA== X-Google-Smtp-Source: APXvYqwdwBCzqkc4UQB3eGdqOHqI/e4q1PdOcvp33Okdte4nGO+ldcr3OcZHs74ztieN7MdlwUJSYg== X-Received: by 2002:a63:4824:: with SMTP id v36mr855635pga.343.1579737366177; Wed, 22 Jan 2020 15:56:06 -0800 (PST) Received: from localhost ([2620:0:1000:2514:7f69:cd98:a2a2:a03d]) by smtp.gmail.com with ESMTPSA id b1sm69151pfp.44.2020.01.22.15.56.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Jan 2020 15:56:05 -0800 (PST) Date: Wed, 22 Jan 2020 15:56:05 -0800 (PST) X-Google-Original-Date: Wed, 22 Jan 2020 15:54:50 PST (-0800) From: Palmer Dabbelt X-Google-Original-From: Palmer Dabbelt Subject: Re: [PATCH] macb: Don't unregister clks unconditionally CC: davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, nicolas.ferre@microchip.com, yash.shah@sifive.com, linux@roeck-us.net To: sboyd@kernel.org In-Reply-To: <20200104001921.225529-1-sboyd@kernel.org> References: <20200104001921.225529-1-sboyd@kernel.org> Message-ID: Mime-Version: 1.0 (MHng) Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 03 Jan 2020 16:19:21 PST (-0800), sboyd@kernel.org wrote: > The only clk init function in this driver that register a clk is > fu540_c000_clk_init(), and thus we need to unregister the clk when this > driver is removed on that platform. Other init functions, for example > macb_clk_init(), don't register clks and therefore we shouldn't > unregister the clks when this driver is removed. Convert this > registration path to devm so it gets auto-unregistered when this driver > is removed and drop the clk_unregister() calls in driver remove (and > error paths) so that we don't erroneously remove a clk from the system > that isn't registered by this driver. > > Otherwise we get strange crashes with a use-after-free when the > devm_clk_get() call in macb_clk_init() calls clk_put() on a clk pointer > that has become invalid because it is freed in clk_unregister(). > > Cc: Nicolas Ferre > Cc: Yash Shah > Reported-by: Guenter Roeck > Fixes: c218ad559020 ("macb: Add support for SiFive FU540-C000") > Signed-off-by: Stephen Boyd > --- > drivers/net/ethernet/cadence/macb_main.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c > index 9c767ee252ac..7dce403fd27c 100644 > --- a/drivers/net/ethernet/cadence/macb_main.c > +++ b/drivers/net/ethernet/cadence/macb_main.c > @@ -4069,7 +4069,7 @@ static int fu540_c000_clk_init(struct platform_device *pdev, struct clk **pclk, > mgmt->rate = 0; > mgmt->hw.init = &init; > > - *tx_clk = clk_register(NULL, &mgmt->hw); > + *tx_clk = devm_clk_register(&pdev->dev, &mgmt->hw); > if (IS_ERR(*tx_clk)) > return PTR_ERR(*tx_clk); > > @@ -4397,7 +4397,6 @@ static int macb_probe(struct platform_device *pdev) > > err_disable_clocks: > clk_disable_unprepare(tx_clk); > - clk_unregister(tx_clk); > clk_disable_unprepare(hclk); > clk_disable_unprepare(pclk); > clk_disable_unprepare(rx_clk); > @@ -4427,7 +4426,6 @@ static int macb_remove(struct platform_device *pdev) > pm_runtime_dont_use_autosuspend(&pdev->dev); > if (!pm_runtime_suspended(&pdev->dev)) { > clk_disable_unprepare(bp->tx_clk); > - clk_unregister(bp->tx_clk); > clk_disable_unprepare(bp->hclk); > clk_disable_unprepare(bp->pclk); > clk_disable_unprepare(bp->rx_clk); Reviewed-by: Palmer Dabbelt Thanks!