From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752390AbcFUPsb (ORCPT ); Tue, 21 Jun 2016 11:48:31 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:43498 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752276AbcFUPs1 (ORCPT ); Tue, 21 Jun 2016 11:48:27 -0400 Subject: Re: [PATCH] ppc: Fix BPF JIT for ABIv2 To: Thadeu Lima de Souza Cascardo , Michael Ellerman References: <908d3552b5eb240b28f70aee7c4c86e2b600aa02.1465304785.git.naveen.n.rao@linux.vnet.ibm.com> <3rWKtT2tSrz9t2G@ozlabs.org> <20160617130042.GO3516@indiana.gru.redhat.com> <20160619174914.GC8886@naverao1-tp.localdomain> <20160620185620.GD3516@indiana.gru.redhat.com> <20160621085807.GE8886@naverao1-tp.localdomain> <1466507748.18876.3.camel@ellerman.id.au> <20160621144725.GH3516@indiana.gru.redhat.com> CC: "Naveen N. Rao" , , , , Matt Evans , Daniel Borkmann , Denis Kirjanov , "Paul Mackerras" , "David S. Miller" , "Ananth N Mavinakayanahalli" From: Alexei Starovoitov Message-ID: <57696137.5020408@fb.com> Date: Tue, 21 Jun 2016 08:45:59 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: <20160621144725.GH3516@indiana.gru.redhat.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [2620:10d:c090:200::7:3198] X-ClientProxiedBy: BY2PR16CA0025.namprd16.prod.outlook.com (10.164.126.163) To CY1PR15MB0187.namprd15.prod.outlook.com (10.163.48.149) X-MS-Office365-Filtering-Correlation-Id: 6186e2f6-f458-4f09-c3b0-08d399eb26d4 X-Microsoft-Exchange-Diagnostics: 1;CY1PR15MB0187;2:6ALE5VGGHFu+5RdsHk3VHFKk3qZvBDPNQeGsVk2MUfiH9pcTwjfs9aZRBh2r7xFahdYHPtb1xpyUiKF869D3tQ3dMYIAn5MfuoYcIRW3/Ls6wVdX35Ou/q5vLqFbciesgeooxq4bQat0UwbmhIeYmwWrlRaAUvKe+WgIV8YNtodwAKxM8byEuC65HovVyuDg;3:usTo3V/CZWu4cRFDK06boP7VBIK1QgxzQeUe+oJoKjw9KBGiMpPGpjVi63IKYvpc8hr2dyINgmMgc46U1f+CNxxhGMbPTZ85q6ELHleoaPMhmf4Q1h42IM+uXshUGTnY X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:CY1PR15MB0187; X-Microsoft-Exchange-Diagnostics: 1;CY1PR15MB0187;25: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;20:/LwV4/btkKL9vJ7WPFJEKq1nrwMzW1Ncdu3Avieu9l944cfcVX819mKziTHT7Xle0JxfmYS4y82DnRtfvoA7H4tAeN8QnYvlS8EVWknZIEmA9jjShDEAcrGdK/0mc4jzZps8C/KP0H5ylau7w0JSLu58zGoHLgqdfbKyvCpmhFU= X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:; X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(601004)(2401047)(5005006)(8121501046)(10201501046)(3002001);SRVR:CY1PR15MB0187;BCL:0;PCL:0;RULEID:;SRVR:CY1PR15MB0187; X-Microsoft-Exchange-Diagnostics: 1;CY1PR15MB0187;4:LV80sod9bpgu7jtrLkasMsAlRjdK0QfXYiMefX2bWHaJia2AQvrkF3AxBIoYstrdVJUCVDxqRsLc1qckvYRxqQwc/hismg297r1LcZ9/i/zQOrs5gWlIYzBWxzoiO6NhNbMavFomhAXm5NuSlQC0Q94ZY7F1SMJarx7AXL7T1D5UBMaAQxEzp/RgyKjAltfwOqmGsQfUuw+kr2uSfg9fUzL+hDFozWCkvrVMcIn/xRXylKp8udNUtN5xaTTbIQmUW561J5RFaQw1QrfOjemRaAX3HH65DPq9op6eALjjqr5boPlibQZrXp26aZeT7DtxbEyltvHRp9yC2n1bo8l1y89uhR6eaO+QHDjM7jjsTlHvXhQfWtabLkN8a4sWjPfA X-Forefront-PRVS: 098076C36C X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10019020)(4630300001)(6009001)(7916002)(377454003)(24454002)(199003)(189002)(64126003)(23746002)(4326007)(8676002)(81156014)(81166006)(86362001)(2906002)(1706002)(19580395003)(36756003)(83506001)(99136001)(230700001)(76176999)(5001770100001)(54356999)(65816999)(87266999)(42186005)(117636001)(59896002)(2950100001)(77096005)(50466002)(6116002)(4001350100001)(189998001)(105586002)(106356001)(101416001)(50986999)(92566002)(47776003)(122286003)(65806001)(97736004)(65956001)(7846002)(68736007)(7736002)(93886004)(586003)(3826002)(217873001)(42262002)(62816006);DIR:OUT;SFP:1102;SCL:1;SRVR:CY1PR15MB0187;H:[IPv6:2620:10d:c082:1055:7016:8eb0:367f:5541];FPR:;SPF:None;PTR:InfoNoRecords;A:1;MX:1;LANG:en; X-Microsoft-Exchange-Diagnostics: =?Windows-1252?Q?1;CY1PR15MB0187;23:UdcVW3QI7OvDrceqEEga7xBVeUYqZNUB182Tu?= =?Windows-1252?Q?MqmpliZ1IMdt+3a8sNjUQlmB6vRjUglrcmTD/cBtJlzNeClQcJGhE1zz?= =?Windows-1252?Q?ZjBA4Lmbqu3SRWJe1fb9gqexX2+enlkJK0c3j992lBSznNCoYPk4UmUf?= =?Windows-1252?Q?b8VUo1WOoHuWAmGNHPlcRwhSYrjNDiB8z8p5a4dfR2WYswZvNsV1BKGk?= =?Windows-1252?Q?oZCYPsm1Dw6oh+7UdiP1u7m881pG63bZyDFgOKFI5vk167Lswm5jHWYF?= =?Windows-1252?Q?pj/K0Whr4tegfWH7FBURDxNpOtbbopweIW+sZRQ6IPfkFgkN+f2HbAEW?= =?Windows-1252?Q?UVtVB6xBYzAZzClfwi5VZjC0CS9YknQE4j1d+N71yptNiAZzilL2yj71?= =?Windows-1252?Q?bt+NL4I2Ingx65lO7EevGiu40j0Dy+Hy7AoflYuTuKSYXrPlfjXvqqZy?= =?Windows-1252?Q?whZJHGve2OVhXZDXhTXgLkQ6jzjaVG9zRNqsqv9fI/o/CFH1g4fbVG4u?= =?Windows-1252?Q?AJNUHiVt9a866sWdxQI0qN8RdRFh/Kf+msASY6TtWe91rAGmxjVzJDLN?= =?Windows-1252?Q?w68bcjWZlqS8XivpiozJTxcXUqYgACOZaWU9vUPToaBE60QWJ8Usdehd?= =?Windows-1252?Q?G1E0OsEuTYvSd9696Rbj1b2HM8PULa2qFLHcLTQJ/e5fy0o8NyxzKPgg?= =?Windows-1252?Q?fKJ3Yy7XTzBLCMjfx93ekwrAAkOs0wQibYOdpU+nvX96X+Hl5PXcnY3w?= =?Windows-1252?Q?1bQGx8qZWOwgrCLVWPVKcVT0WTWrT2wogD9JiuJSARI6bhhiiP2cHy8d?= =?Windows-1252?Q?T/SnXbhRDoe/Um0r5gyGi5SM2hrjsz6vsl/IFGxMJ4GMa9yjRoCEmONd?= =?Windows-1252?Q?3x83vbRR8fXpCHvqK9FND9bglVvH7/25o95FokmseVdPVxTI7GloXfCE?= =?Windows-1252?Q?OjeMXVZtjP0A5o3+Okb3jAEo1s85w3yANhKqaANyMRm2FvsV/4R35jfe?= =?Windows-1252?Q?rjjinjr++EcXMeWjZlyuzME+34ddfSPVDYnUxleeCO94x4XFhyahP0Ee?= =?Windows-1252?Q?rFEZtNyoEmXzhnBOaCqjHq/RjoPXF5dM4GIQsj6YR/Lw9vSjzlEg2mJk?= =?Windows-1252?Q?Qvef21a7mZo8mCb2+GFfOhKWNDXvBl9CYQfRQqFDcLDyiLbrnMh2Bf7d?= =?Windows-1252?Q?jcuA2OEUwdLm5qzWWRX+trU5UW06H6kpN+Vi3xkr5P1PXmFnpK21HiD/?= =?Windows-1252?Q?rcop0+D9z19T3dit07BnErBmVhV4c5BULtIY9liZj7Wu7UkeJ2MuED/R?= =?Windows-1252?Q?LA4GfIB7duKasjJURnqbhZEHntIaMlTT8D64MNiDwJz7hCgx6Mggzwg8?= =?Windows-1252?Q?xzrHKjZRmfrlJ9AP3CPytRsbrtDDcjvmlb+pfWv++o0+kal26kJvET0+?= =?Windows-1252?Q?X9BXdrsh9dKNjORHWQV?= X-Microsoft-Exchange-Diagnostics: 1;CY1PR15MB0187;6:Bajv+Dc3HSzgbmVfRss0hsbefm/ETBKW2f2K+f8CT3S52tYiz13Vm0FDW3HfIPr3WKHYYt+v+pM0+wVXw2tlpQThoZn4VxNwBukZCTArzLqKHSHg2Yjq5s9vG9Rt0Rt+VP7eIZiSLQT3UByRqQ5s2s6BsT62FLq6G7VPcfTDZfVLgyIPlS2MGhoJWVkVRTlbp5G+BbQBFnQbJFeFe3S6fXhhKT3dChDyCqARCMKmf8wuCiwTR9cAPr9eXCYw8uza2SX+nAONW310jyc4Up20ApJpiz4WC5X2pXZ6LMYA9Jo=;5:CYLN/gdBoTbpJJOBCYq4sNtE4OGYhHbc8gbCWFT6+Ef1d0Db2HLxd6hW5YDpK0keQ4tBd0J7pmAotX5pGv2NyQsLMJjxn2T/T8Y4xtUNUTf2BRAeh1dBq9Dln1mTustcPI1w2YxHr5cHIBlRPIfSVg==;24:wcg6epa/DXiowGp7CebKLABXWaQxr3punQhQT5vcOXUK6P/WpfeUWkaL4YvoIinwVIQwvv5GW5t/EFewNHuNwddkd44JyhcvtsO1tOZVeCM=;7:50BNm6r71RErpYbo6eIiksbpVhk7wsNUwx624ERFN/Pme9GuV57pNXZwScHFZ8w9Eu49cM/kfzPGiPCVLdK8/DEOaLo2rytC9W3uhfqRt2LxwY/XTtuQPUlenRJzp2XaPvxx5I8UrouVDec9vdaiRFIwfEr/4IpBroL7OBWF5leR7VU/fIzU9V7v1mRny1m5q3YMje0MRz4rrBbDWxX6SPKM1kksrmK1v98Q+72cRhyPT+3RKaL91ZpUKu7PjzoB SpamDiagnosticOutput: 1:99 SpamDiagnosticMetadata: NSPM X-Microsoft-Exchange-Diagnostics: 1;CY1PR15MB0187;20:9cKhJdg7aGmRi/kSoOp28S2pOq2bWEO6OB5qFXzk96hweNBd5X9gj2c7u3mMTgquDAjAzEL/Si2Pq38/VAkH0IqHe6PlMQlGixtTJgYVjNH++vIOAcwS8YnB4sPN3Ov+WX2xSW889PWnT6o5BXrFa57RjvUwGaDbwBGSpLJAxLE= X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Jun 2016 15:46:02.7045 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY1PR15MB0187 X-OriginatorOrg: fb.com X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-06-21_07:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/21/16 7:47 AM, Thadeu Lima de Souza Cascardo wrote: >>> >>> The calling convention is different with ABIv2 and so we'll need changes >>> in bpf_slow_path_common() and sk_negative_common(). >> >> How big would those changes be? Do we know? >> >> How come no one reported this was broken previously? This is the first I've >> heard of it being broken. >> > > I just heard of it less than two weeks ago, and only could investigate it last > week, when I realized mainline was also affected. > > It looks like the little-endian support for classic JIT were done before the > conversion to ABIv2. And as JIT is disabled by default, no one seems to have > exercised it. it's not a surprise unfortunately. The JITs that were written before test_bpf.ko was developed were missing corner cases. Typical tcpdump would be fine, but fragmented packets, negative offsets and out-out-bounds wouldn't be handled correctly. I'd suggest to validate the stable backport with test_bpf as well.