From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 5D006A0487 for ; Thu, 4 Jul 2019 20:43:11 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 714052BE5; Thu, 4 Jul 2019 20:43:10 +0200 (CEST) Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id F3E402BE3 for ; Thu, 4 Jul 2019 20:43:08 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Jul 2019 11:43:08 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,451,1557212400"; d="scan'208";a="155107652" Received: from fyigit-mobl.ger.corp.intel.com (HELO [10.237.221.30]) ([10.237.221.30]) by orsmga007.jf.intel.com with ESMTP; 04 Jul 2019 11:43:06 -0700 To: Bruce Richardson , Stephen Hemminger Cc: dev@dpdk.org, Chas Williams , "John W. Linville" References: <20190408160419.7409-1-stephen@networkplumber.org> <20190408164112.12471-1-stephen@networkplumber.org> <7e03b000-f4d4-71c3-5978-8a8623d7ace5@intel.com> <20190412150833.63c41806@shemminger-XPS-13-9360> <3dff5ba9-3965-be8d-7bd5-d8504a66c130@intel.com> <20190416094212.GA1865@bricha3-MOBL.ger.corp.intel.com> <20190416080336.3b8e16a6@xps13.lan> <20190416151351.GA1875@bricha3-MOBL.ger.corp.intel.com> From: Ferruh Yigit Openpgp: preference=signencrypt Autocrypt: addr=ferruh.yigit@intel.com; prefer-encrypt=mutual; keydata= mQINBFXZCFABEADCujshBOAaqPZpwShdkzkyGpJ15lmxiSr3jVMqOtQS/sB3FYLT0/d3+bvy qbL9YnlbPyRvZfnP3pXiKwkRoR1RJwEo2BOf6hxdzTmLRtGtwWzI9MwrUPj6n/ldiD58VAGQ +iR1I/z9UBUN/ZMksElA2D7Jgg7vZ78iKwNnd+vLBD6I61kVrZ45Vjo3r+pPOByUBXOUlxp9 GWEKKIrJ4eogqkVNSixN16VYK7xR+5OUkBYUO+sE6etSxCr7BahMPKxH+XPlZZjKrxciaWQb +dElz3Ab4Opl+ZT/bK2huX+W+NJBEBVzjTkhjSTjcyRdxvS1gwWRuXqAml/sh+KQjPV1PPHF YK5LcqLkle+OKTCa82OvUb7cr+ALxATIZXQkgmn+zFT8UzSS3aiBBohg3BtbTIWy51jNlYdy ezUZ4UxKSsFuUTPt+JjHQBvF7WKbmNGS3fCid5Iag4tWOfZoqiCNzxApkVugltxoc6rG2TyX CmI2rP0mQ0GOsGXA3+3c1MCdQFzdIn/5tLBZyKy4F54UFo35eOX8/g7OaE+xrgY/4bZjpxC1 1pd66AAtKb3aNXpHvIfkVV6NYloo52H+FUE5ZDPNCGD0/btFGPWmWRmkPybzColTy7fmPaGz cBcEEqHK4T0aY4UJmE7Ylvg255Kz7s6wGZe6IR3N0cKNv++O7QARAQABtCVGZXJydWggWWln aXQgPGZlcnJ1aC55aWdpdEBpbnRlbC5jb20+iQJUBBMBCgA+AhsDAh4BAheABQkI71rKFiEE 0jZTh0IuwoTjmYHH+TPrQ98TYR8FAlznMMQFCwkIBwMFFQoJCAsFFgIDAQAACgkQ+TPrQ98T YR/B9Q//a57esjq996nfZVm7AsUl7zbvhN+Ojity25ib2gcSVVsAN2j6lcQS4hf6/OVvRj3q CgebJ4o2gXR6X12UzWBJL7NE8Xpc70MvUIe0r11ykurQ9n9jUaWMjxdSqBPF93hU+Z/MZe5M 1rW5O2VJLuTJzkDw3EYUCbHOwPjeaS8Qqj3RI0LYbGthbHBIp9CsjkgsJSjTT5GQ8AQWkE7I z+hvPx6f1rllfjxFyi4DI3jLhAI+j1Nm+l+ESyoX59HrLTHAvq4RPkLpTnGBj9gOnJ+5sVEr GE0fcffsNcuMSkpqSEoJCPAHmChoLgezskhhsy0BiU3xlSIj1Dx2XMDerUXFOK3ftlbYNRte HQy4EKubfZRB8H5Rvcpksom3fRBDcJT8zw+PTH14htRApU9f8I/RamQ7Ujks7KuaB7JX5QaG gMjfPzHGYX9PfF6KIchaFmAWLytIP1t0ht8LpJkjtvUCSQZ2VxpCXwKyUzPDIF3co3tp90o7 X07uiC5ymX0K0+Owqs6zeslLY6DMxNdt8ye+h1TVkSZ5g4dCs4C/aiEF230+luL1CnejOv/K /s1iSbXQzJNM7be3FlRUz4FdwsfKiJJF7xYALSBnSvEB04R7I2P2V9Zpudkq6DRT6HZjBeJ1 pBF2J655cdoenPBIeimjnnh4K7YZBzwOLJf2c6u76fe5Ag0EV9ZMvgEQAKc0Db17xNqtSwEv mfp4tkddwW9XA0tWWKtY4KUdd/jijYqc3fDD54ESYpV8QWj0xK4YM0dLxnDU2IYxjEshSB1T qAatVWz9WtBYvzalsyTqMKP3w34FciuL7orXP4AibPtrHuIXWQOBECcVZTTOdZYGAzaYzxiA ONzF9eTiwIqe9/oaOjTwTLnOarHt16QApTYQSnxDUQljeNvKYt1lZE/gAUUxNLWsYyTT+22/ vU0GDUahsJxs1+f1yEr+OGrFiEAmqrzpF0lCS3f/3HVTU6rS9cK3glVUeaTF4+1SK5ZNO35p iVQCwphmxa+dwTG/DvvHYCtgOZorTJ+OHfvCnSVjsM4kcXGjJPy3JZmUtyL9UxEbYlrffGPQ I3gLXIGD5AN5XdAXFCjjaID/KR1c9RHd7Oaw0Pdcq9UtMLgM1vdX8RlDuMGPrj5sQrRVbgYH fVU/TQCk1C9KhzOwg4Ap2T3tE1umY/DqrXQgsgH71PXFucVjOyHMYXXugLT8YQ0gcBPHy9mZ qw5mgOI5lCl6d4uCcUT0l/OEtPG/rA1lxz8ctdFBVOQOxCvwRG2QCgcJ/UTn5vlivul+cThi 6ERPvjqjblLncQtRg8izj2qgmwQkvfj+h7Ex88bI8iWtu5+I3K3LmNz/UxHBSWEmUnkg4fJl Rr7oItHsZ0ia6wWQ8lQnABEBAAGJAjwEGAEKACYCGwwWIQTSNlOHQi7ChOOZgcf5M+tD3xNh HwUCXOcvZgUJBvIWKAAKCRD5M+tD3xNhHxhBD/9toXMIaPIVFd9w1nKsRDM1GE6gZe4jie8q MJpeHB9O+936fSXA0W2X0het60wJQQ45O8TpTcxpc9nGzcE4MTaLAI3E8TjIXAO0cPqUNLyp g0DXezmTw5BU+SKZ51+jSKOtFmzJCHOJZQaMeCHD+G3CrdUHQVQBb5AeuH3KFv9ltgDcWsc8 YO70o3+tGHwcEnyXLdrI0q05wV7ncnLdkgVo+VUN4092bNMPwYly1TZWcU3Jw5gczOUEfTY7 sgo6E/sGX3B+FzgIs5t4yi1XOweCAQ/mPnb6uFeNENEFyGKyMG1HtjwBqnftbiFO3qitEIUY xWGQH23oKscv7i9lT0gg2D+ktzZhVWwHJVY/2vWSB9aCSWChcH2BT+lWrkwSpoPhy+almM84 Qz2wF72/d4ce4L27pSrS+vOXtXHLGOOGcAn8yr9TV0kM4aR+NbGBRXGKhG6w4lY54uNd9IBa ARIPUhij5JSygxZCBaJKo+X64AHGkk5bXq+f0anwAMNuJXbYC/lz4DEdKmPgQGShOWNs1Y1a N3cI87Hun/RBVwQ0a3Tr1g6OWJ6xK8cYbMcoR8NZ7L9ALMeJeuUDQR39+fEeHg/6sQN0P0mv 0sL+//BAJphCzDk8ztbrFw+JaPtgzZpRSM6JhxnY+YMAsatJRXA0WSpYP5zzl7yu/GZJIgsv VQ== Message-ID: <1eba2972-6bcd-e327-4d66-88f95677d647@intel.com> Date: Thu, 4 Jul 2019 19:43:05 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190416151351.GA1875@bricha3-MOBL.ger.corp.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v2] net/af_packet: fix vlan_insert corruption X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 4/16/2019 4:13 PM, Bruce Richardson wrote: > On Tue, Apr 16, 2019 at 08:03:36AM -0700, Stephen Hemminger wrote: >> On Tue, 16 Apr 2019 10:42:13 +0100 >> Bruce Richardson wrote: >> >>> On Tue, Apr 16, 2019 at 10:37:07AM +0100, Ferruh Yigit wrote: >>>> On 4/12/2019 11:08 PM, Stephen Hemminger wrote: >>>>> On Fri, 12 Apr 2019 17:28:17 +0100 >>>>> Ferruh Yigit wrote: >>>>> >>>>>> On 4/8/2019 5:41 PM, Stephen Hemminger wrote: >>>>>>> If the af_packet transmit is sending a VLAN packet, >>>>>>> and the transmit path to the kernel os full, then it would >>>>>>> mismanage the outgoing mbuf. The original mbuf would end up >>>>>>> being freed twice, once by AF_PACKET PMD and once by caller. >>>>>> >>>>>> This comment is valid with your new patch [1] that updates 'rte_vlan_insert()' >>>>>> to duplicate the mbuf, right? >>>>>> >>>>>> That patch looks like won't make the release, so I suggest this one wait that >>>>>> patch, although this is harmless on its own, commit log is misleading. >>>>>> >>>>>> [1] >>>>>> https://patches.dpdk.org/patch/51870/ >>>>> >>>>> It was always true, even with existing vlan_insert. >>>>> Existing vlan_insert has issues if it ever creates a clone packet. >>>>> Existing vlan_insert can duplicate mbuf through clone >>>>> >>>> >>>> Right, existing vlan_insert has same issue on af_packet. >>>> >>>> But, should vlan_insert try to duplicate the mbuf when it is shared, does it >>>> worth the complexity it brings? And when that support removed this patch won't >>>> be needed. >>> >>> I don't think vlan insert or other mbuf manipulation APIs should be >>> checking for shared state or not - that's the job of the app. We could have >>> cases where the user does want to modify a shared mbuf. >>> >>> Regards, >>> /Bruce >> >> The vlan_insert code is called on transmit, and there are lots of >> cases where a transmit mbuf might be shared (like TCP stack). And in that >> case inserting the vlan must be non-destructive to the original mbuf. >> >> Whether you want to push the problem to the driver or do it in the >> library, it is still a problem. > > Yes, I agree it's a problem. I'd prefer see it done in the driver than in the > library, since it's higher in the SW stack and has more context information > as to what is safe or not. The patch not more needed with current rte_vlan_insert()