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dkim=pass (2048-bit key) header.d=kernel.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id o0A_1rsHFOUI for ; Wed, 2 Jun 2021 05:50:51 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp3.osuosl.org (Postfix) with ESMTPS id 2A478605DE for ; Wed, 2 Jun 2021 05:50:50 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id A713161360; Wed, 2 Jun 2021 05:50:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622613050; bh=D52BA1TKwtARtppT4vzXwF1FMjDUS7v+afZJl5NMqhQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YAEe4BsGeoDBwhLRcW2MC+qqQPKO0RzuYvo855vjZ+7PlTdDhLa7hcMLN1hyLehy5 cr8fSUnZVkuWitgEaiev4i+fkY8qpSuo2iPoduBxbbxlE2J/RpMyYDxfctDB0V44N0 OeiOOWucg6Cb5DXQ0lXBPPGm3z11zg0is46/quMhY9DIO98PtSWrR0cK6PZ/YAw/CO FTD+lq2911PSop3DCY3/YF7/ZXAawuPzE2dJOtq2BBTreJ4mS0InA6q0TAg+K9ER4Z gz4N/x+wfz9CqieFL1G7O/QiMjnqLidqzBOAh+F9kcZd3YFvb0XCyoaSEnCVsUDCPh N3UiCLC2H4LMg== Date: Wed, 2 Jun 2021 08:50:46 +0300 From: Leon Romanovsky To: Jason Wang Subject: Re: [PATCH] virtio-net: fix the kzalloc/kfree mismatch problem Message-ID: References: <1621821978.04102-1-xuanzhuo@linux.alibaba.com> <36d1b92c-7dc5-f84e-ef86-980b15c39965@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <36d1b92c-7dc5-f84e-ef86-980b15c39965@redhat.com> Cc: Max Gurtovoy , "Guodeqing \(A\)" , "netdev@vger.kernel.org" , "mst@redhat.com" , "virtualization@lists.linux-foundation.org" , "kuba@kernel.org" , "davem@davemloft.net" X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" T24gTW9uLCBNYXkgMjQsIDIwMjEgYXQgMTA6Mzc6MTRBTSArMDgwMCwgSmFzb24gV2FuZyB3cm90 ZToKPiAKPiDlnKggMjAyMS81LzI0IOS4iuWNiDEwOjA2LCBYdWFuIFpodW8g5YaZ6YGTOgo+ID4g T24gTW9uLCAyNCBNYXkgMjAyMSAwMTo0ODo1MyArMDAwMCwgR3VvZGVxaW5nIChBKSA8Z2VmZnJl eS5ndW9AaHVhd2VpLmNvbT4gd3JvdGU6Cj4gPiA+IAo+ID4gPiA+IC0tLS0tT3JpZ2luYWwgTWVz c2FnZS0tLS0tCj4gPiA+ID4gRnJvbTogTWF4IEd1cnRvdm95IFttYWlsdG86bWd1cnRvdm95QG52 aWRpYS5jb21dCj4gPiA+ID4gU2VudDogU3VuZGF5LCBNYXkgMjMsIDIwMjEgMTU6MjUKPiA+ID4g PiBUbzogR3VvZGVxaW5nIChBKSA8Z2VmZnJleS5ndW9AaHVhd2VpLmNvbT47IG1zdEByZWRoYXQu Y29tCj4gPiA+ID4gQ2M6IGphc293YW5nQHJlZGhhdC5jb207IGRhdmVtQGRhdmVtbG9mdC5uZXQ7 IGt1YmFAa2VybmVsLm9yZzsKPiA+ID4gPiB2aXJ0dWFsaXphdGlvbkBsaXN0cy5saW51eC1mb3Vu ZGF0aW9uLm9yZzsgbmV0ZGV2QHZnZXIua2VybmVsLm9yZwo+ID4gPiA+IFN1YmplY3Q6IFJlOiBb UEFUQ0hdIHZpcnRpby1uZXQ6IGZpeCB0aGUga3phbGxvYy9rZnJlZSBtaXNtYXRjaCBwcm9ibGVt Cj4gPiA+ID4gCj4gPiA+ID4gCj4gPiA+ID4gT24gNS8yMi8yMDIxIDExOjAyIEFNLCBndW9kZXFp bmcgd3JvdGU6Cj4gPiA+ID4gPiBJZiB0aGUgdmlydGlvX25ldCBkZXZpY2UgZG9lcyBub3Qgc3Vw cHVydCB0aGUgY3RybCBxdWV1ZSBmZWF0dXJlLCB0aGUKPiA+ID4gPiA+IHZpLT5jdHJsIHdhcyBu b3QgYWxsb2NhdGVkLCBzbyB0aGVyZSBpcyBubyBuZWVkIHRvIGZyZWUgaXQuCj4gPiA+ID4geW91 IGRvbid0IG5lZWQgdGhpcyBjaGVjay4KPiA+ID4gPiAKPiA+ID4gPiBmcm9tIGtmcmVlIGRvYzoK PiA+ID4gPiAKPiA+ID4gPiAiSWYgQG9ianAgaXMgTlVMTCwgbm8gb3BlcmF0aW9uIGlzIHBlcmZv cm1lZC4iCj4gPiA+ID4gCj4gPiA+ID4gVGhpcyBpcyBub3QgYSBidWcuIEkndmUgc2V0IHZpLT5j dHJsIHRvIGJlIE5VTEwgaW4gY2FzZSAhdmktPmhhc19jdnEuCj4gPiA+ID4gCj4gPiA+ID4gCj4g PiA+ICAgIHllcywgIHRoaXMgaXMgbm90IGEgYnVnLCB0aGUgcGF0Y2ggaXMganVzdCBhIG9wdGlt aXphdGlvbiwgYmVjYXVzZSB0aGUgdmktPmN0cmwgbWF5YmUKPiA+ID4gICAgYmUgZnJlZWQgd2hp Y2ggIHdhcyBub3QgYWxsb2NhdGVkLCB0aGlzIG1heSBnaXZlIHBlb3BsZSBhIG1pc3VuZGVyc3Rh bmRpbmcuCj4gPiA+ICAgIFRoYW5rcy4KPiA+IAo+ID4gSSB0aGluayBpdCBtYXkgYmUgZW5vdWdo IHRvIGFkZCBhIGNvbW1lbnQsIGFuZCB0aGUgY29kZSBkb2VzIG5vdCBuZWVkIHRvIGJlCj4gPiBt b2RpZmllZC4KPiA+IAo+ID4gVGhhbmtzLgo+IAo+IAo+IE9yIGV2ZW4ganVzdCBsZWF2ZSB0aGUg Y3VycmVudCBjb2RlIGFzIGlzLiBBIGxvdCBvZiBrZXJuZWwgY29kZXMgd2FzIHdyb3RlCj4gdW5k ZXIgdGhlIGFzc3VtcHRpb24gdGhhdCBrZnJlZSgpIHNob3VsZCBkZWFsIHdpdGggTlVMTC4KCkl0 IGlzIG5vdCBhc3N1bXB0aW9uIGJ1dCBzdGFuZGFyZCBwcmFjdGljZSB0aGF0IGNhbiBiZSBzZWVu IGFzIHNpZGUKZWZmZWN0IG9mICI3KSBDZW50cmFsaXplZCBleGl0aW5nIG9mIGZ1bmN0aW9ucyIg c2VjdGlvbiBvZiBjb2Rpbmctc3R5bGUucnN0LgoKVGhhbmtzCl9fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fClZpcnR1YWxpemF0aW9uIG1haWxpbmcgbGlzdApW aXJ0dWFsaXphdGlvbkBsaXN0cy5saW51eC1mb3VuZGF0aW9uLm9yZwpodHRwczovL2xpc3RzLmxp bnV4Zm91bmRhdGlvbi5vcmcvbWFpbG1hbi9saXN0aW5mby92aXJ0dWFsaXphdGlvbg== 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=-6.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,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 EC859C47083 for ; Wed, 2 Jun 2021 05:50:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B8F3161375 for ; Wed, 2 Jun 2021 05:50:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230245AbhFBFwd (ORCPT ); Wed, 2 Jun 2021 01:52:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:46510 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229779AbhFBFwc (ORCPT ); Wed, 2 Jun 2021 01:52:32 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A713161360; Wed, 2 Jun 2021 05:50:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622613050; bh=D52BA1TKwtARtppT4vzXwF1FMjDUS7v+afZJl5NMqhQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YAEe4BsGeoDBwhLRcW2MC+qqQPKO0RzuYvo855vjZ+7PlTdDhLa7hcMLN1hyLehy5 cr8fSUnZVkuWitgEaiev4i+fkY8qpSuo2iPoduBxbbxlE2J/RpMyYDxfctDB0V44N0 OeiOOWucg6Cb5DXQ0lXBPPGm3z11zg0is46/quMhY9DIO98PtSWrR0cK6PZ/YAw/CO FTD+lq2911PSop3DCY3/YF7/ZXAawuPzE2dJOtq2BBTreJ4mS0InA6q0TAg+K9ER4Z gz4N/x+wfz9CqieFL1G7O/QiMjnqLidqzBOAh+F9kcZd3YFvb0XCyoaSEnCVsUDCPh N3UiCLC2H4LMg== Date: Wed, 2 Jun 2021 08:50:46 +0300 From: Leon Romanovsky To: Jason Wang Cc: Xuan Zhuo , "Guodeqing (A)" , "davem@davemloft.net" , "kuba@kernel.org" , "virtualization@lists.linux-foundation.org" , "netdev@vger.kernel.org" , Max Gurtovoy , "mst@redhat.com" Subject: Re: [PATCH] virtio-net: fix the kzalloc/kfree mismatch problem Message-ID: References: <1621821978.04102-1-xuanzhuo@linux.alibaba.com> <36d1b92c-7dc5-f84e-ef86-980b15c39965@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <36d1b92c-7dc5-f84e-ef86-980b15c39965@redhat.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, May 24, 2021 at 10:37:14AM +0800, Jason Wang wrote: > > 在 2021/5/24 上午10:06, Xuan Zhuo 写道: > > On Mon, 24 May 2021 01:48:53 +0000, Guodeqing (A) wrote: > > > > > > > -----Original Message----- > > > > From: Max Gurtovoy [mailto:mgurtovoy@nvidia.com] > > > > Sent: Sunday, May 23, 2021 15:25 > > > > To: Guodeqing (A) ; mst@redhat.com > > > > Cc: jasowang@redhat.com; davem@davemloft.net; kuba@kernel.org; > > > > virtualization@lists.linux-foundation.org; netdev@vger.kernel.org > > > > Subject: Re: [PATCH] virtio-net: fix the kzalloc/kfree mismatch problem > > > > > > > > > > > > On 5/22/2021 11:02 AM, guodeqing wrote: > > > > > If the virtio_net device does not suppurt the ctrl queue feature, the > > > > > vi->ctrl was not allocated, so there is no need to free it. > > > > you don't need this check. > > > > > > > > from kfree doc: > > > > > > > > "If @objp is NULL, no operation is performed." > > > > > > > > This is not a bug. I've set vi->ctrl to be NULL in case !vi->has_cvq. > > > > > > > > > > > yes, this is not a bug, the patch is just a optimization, because the vi->ctrl maybe > > > be freed which was not allocated, this may give people a misunderstanding. > > > Thanks. > > > > I think it may be enough to add a comment, and the code does not need to be > > modified. > > > > Thanks. > > > Or even just leave the current code as is. A lot of kernel codes was wrote > under the assumption that kfree() should deal with NULL. It is not assumption but standard practice that can be seen as side effect of "7) Centralized exiting of functions" section of coding-style.rst. Thanks