From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E113425B1E0 for ; Mon, 18 Aug 2025 16:30:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=205.220.165.32 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755534632; cv=fail; b=CvZtH8x9PqMj2nTHt7omgTuR/22pf2sHaWYdIRK3bY52UcR7pVfovGowXc0mJRE5SDPhL18UJshQ6qE0M6PqcDBYUTK+WKim1kTEM6RZRFNuEy6SgTLYqjfWdhqnbSSMwbwGWiBjXVDPmZ/YnoCEbZvZKLMMvK9gCyD9frzca6M= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755534632; c=relaxed/simple; bh=+DmM/etB+9ot6qxFc8M6mUEsLPUVC+FkQM7mwzNI47g=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=rb4yebPPZiKngEF1kfzpe+MBKgw4YcZPMWRNUleZVRMfCnYldJcQO29OTs15WX/tIr04KuWNYAEo7gvw8EL0TEn/TmI+6dvEC2lrwxU61oDNDXcjq4NWtocZxCohINFpn8gyNF/14H/RjmZuhZUpGSbHq7Nu5deVEXdGSPfnt/g= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com; spf=pass smtp.mailfrom=oracle.com; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b=RrsGvIHt; dkim=fail (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b=h5U2pwi/ reason="signature verification failed"; arc=fail smtp.client-ip=205.220.165.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oracle.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="RrsGvIHt"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b="h5U2pwi/" Received: from pps.filterd (m0246617.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 57IEtrrU026746 for ; Mon, 18 Aug 2025 16:30:30 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s= corp-2025-04-25; bh=eoibgKp90OR2yQQoisz6HL3RGq9MgcHdEP76vHGYKS8=; b= RrsGvIHt1icXVl5GHSjx/n1dfHo//AJuF9k11O2QySYHTzgTzqs4Re14XIC73Iup Qpcop7gUev4vUO29Kq2+TzA/hS0q8kCfKWvil6cmefqCyRPCnf3qiTHEzTJNTg7r YwJ0HkhuGpoHIUxLn6237/xtu064R2ut5UVM21TZD1nsUoPfQZ2WEbqOzSO5jyn6 75ClGSOyu177n9U94P1k8f7cae0yRbUa2MmUeY2adx7cFLPJT8D6PJDWr13WQqx4 0SVVf/qDQOlfQ6Gs0NgXAviRdjGXLju1+9x56aPe4x9TvXHOLU1SGSHcfX0LBQYI 7OAkAof8dtZGRDap5t6drw== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 48jjhwuft5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Mon, 18 Aug 2025 16:30:29 +0000 (GMT) Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 57IF16lW036849 for ; Mon, 18 Aug 2025 16:30:28 GMT Received: from cy3pr05cu001.outbound.protection.outlook.com (mail-westcentralusazon11013032.outbound.protection.outlook.com [40.93.201.32]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 48jge9qt55-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Mon, 18 Aug 2025 16:30:28 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=u/YEJH7jHqGedrX6iYB5pk2M9Ggc0DabjA12PUrhCU1+6FoMxuyTNwIXqUrbTx8pxWdyd+gytbitALDY/kLF/lGSOSwlU/2EH7OmF6xah8d+p5u2+JVh2EM8c5dikc7Bp8TUh7EgWKbQabR1HCV/Tg5G/xI68MPUMtakUTuZM6ybOm6cOeaeeXGDd8mE2jvHwfcsFapAChEnjaSX7UZSz1+ztVcXtESD9WQiRisfXa+TYtONaevIk4RcrbWOof5Lg1smfhFhgypNbCWk50XguUFgAEHkPCLVVJWGK4ykFhw7bKwEdQvz2eM+dS88SbAucXZgsCmL2Ls2a/LBjHZlWw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=R205wjj88Z4zzQFx0XhytV8sOd/f82Ve87Tuj7H3rCU=; b=AkhqkNLk0lZoU6oG0p2JVix9cyBPsx+6dTuuEVo16g+rroy8NWzu/XNja4Og9tGSZGotIBij5zu4WS+3AcSRiVb9ooULgn4mRRBY4sxrbwQpfdCb8nSVh6mDX55L6zGwew2erqV6vtGefxWVXu44JCPDxHdJcmW9Mp/VRXGCuRxD1WWGt8AYd2bSC9XLPUrm2kIuHofSfF9EoyTFrLvwIWadJtRy3iaQTssU4IeeGJ4tCIbLaGlEhUjnBqjNbrrYnwPboYpDK/7xXpG5MhIFKuCX/eCqMO3LmR97H4rtZ2/jKAk39AQGRJa685dtOsPI0ObmVAvfE2uEWALGIVr3Iw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=R205wjj88Z4zzQFx0XhytV8sOd/f82Ve87Tuj7H3rCU=; b=h5U2pwi/49nOQUgl5KLq1ukE5PcWkrmwjT68GRJgxBY4Z+2vqs06JIM99irpo+332iR16F3w3SvTvFS2kGzumj0Q4JfESZueNEE92WypyLUaQK7CCn4HOYUGsCAQ9boMLLMQNHD8URSC1Zg0q8mAzWbvWEFVt8xvm4ioGtfVGwc= Received: from SJ0PR10MB5672.namprd10.prod.outlook.com (2603:10b6:a03:3ef::21) by PH7PR10MB6311.namprd10.prod.outlook.com (2603:10b6:510:1b2::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9031.24; Mon, 18 Aug 2025 16:30:25 +0000 Received: from SJ0PR10MB5672.namprd10.prod.outlook.com ([fe80::8800:9203:9f66:174b]) by SJ0PR10MB5672.namprd10.prod.outlook.com ([fe80::8800:9203:9f66:174b%4]) with mapi id 15.20.9031.014; Mon, 18 Aug 2025 16:30:25 +0000 Date: Mon, 18 Aug 2025 12:30:22 -0400 From: Kris Van Hees To: Kris Van Hees Cc: Eugene Loh , dtrace@lists.linux.dev, dtrace-devel@oss.oracle.com Subject: Re: [PATCH] No uprobes on ARM autiasp instructions Message-ID: References: <20250610211042.20522-1-eugene.loh@oracle.com> Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-ClientProxiedBy: BLAPR05CA0020.namprd05.prod.outlook.com (2603:10b6:208:36e::23) To SJ0PR10MB5672.namprd10.prod.outlook.com (2603:10b6:a03:3ef::21) Precedence: bulk X-Mailing-List: dtrace@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ0PR10MB5672:EE_|PH7PR10MB6311:EE_ X-MS-Office365-Filtering-Correlation-Id: 98421c21-5cfc-4110-4c5a-08ddde74892c X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014; X-Microsoft-Antispam-Message-Info: =?iso-8859-1?Q?2l75v9IYYNIoxvww14ekJkkw7pGNvmkd2TnfeqXqQbvKVfca+CnERHZwee?= =?iso-8859-1?Q?LxIXNNNeFeAPJhxEW8Eima0ynLQL7f6aH5uFJJ0hL75iZZNf2Rh3NAHMiO?= =?iso-8859-1?Q?K0/4ZLYisKpQjmhuA72V8T3TJyNLLylYpncMHip3v0xVBZ/UhxI2Lxtjxx?= =?iso-8859-1?Q?SeaXB+nX+K1pf3svM/3YM/B2ShfxsvudAH6T6hfLlhpa8uWyxFp5L+ZnwM?= =?iso-8859-1?Q?1d0xkRz66MhD8CvJ32EbbjlMicIL4yF170I45KmRrJbHQrP0yNWwsLDFRv?= =?iso-8859-1?Q?Rax3gPUcGsXCe38oHfhpP5fzlHWvLbKFjU0FCCCXNpKoEtMJ6caYv91Z/W?= =?iso-8859-1?Q?eVCPkn0JMjQ1fGcPsCB8Z/qm7MXdJa6KGBOUMAlz7Nlq+NZsR9/K8MlhDc?= =?iso-8859-1?Q?d+FfEQlxKEla4aepIuWXzvCQ0DcPSeC3Qb0fSo/2Rt54DMVx73SktoTCjl?= =?iso-8859-1?Q?D0Yk2Lb6sx8Icxcapv5JEPBjc7hcyNwY4LfgQilQgmIyC/pm0xo4vEtnAP?= =?iso-8859-1?Q?jppYd8jIaI7iFjO9JCfBIvKW1VP7C8bMWQio8G2I8unVBB55OuZogyO5mA?= =?iso-8859-1?Q?Hd0ALtNV4eDK+Jyrb58rSkVHj1WREDQh97iz7n0GqSKqhOeglDsBLHwKDt?= =?iso-8859-1?Q?x/TA38cjE/4gLOD2K9Byb8sathRN7Q0CVNVuTcW0qVAoozaxate39hf0rd?= =?iso-8859-1?Q?pFGERjav8VMfS5pt2Tjay00mFewfcudWaOW4LBXFfSH64vH+Ws4/Gdiwlu?= =?iso-8859-1?Q?bVgsB5qU07q85E3wRO43NWmZEomynPeApSwp9dIavFP/MU1WQom9w6CQfS?= =?iso-8859-1?Q?ws96yRa3WW56cYKQNnqZoS3cswVwUZuk/TwnqseeLsAAj/cQqb7DV9LlNl?= =?iso-8859-1?Q?WMt+emyCBy4TIbLkQsANUnBQKn1Mkiem6LhJPtE2yKUE2P/BXkskD0KOj3?= =?iso-8859-1?Q?LL5hvQSokWcbATZGSTESbpz0nYNtaQVQguaEJJR23yJC7ptAaIsiQzTk+P?= =?iso-8859-1?Q?WBaKRWq1rmgfODXWPgtkda6EOYvkrfYKAFFQxzieVBx36zxennsPpviOj9?= =?iso-8859-1?Q?GI8vtq+J4RYZbB0Cem9Wqa+P+HtKOhmWVodXjKlU3POMrM9RvbllT7TPiS?= =?iso-8859-1?Q?ypMERvvXxTQ6ICHFsfypR4sXgT7u63RW+fGZx1poexcw1JpnnZLsPKWHF9?= =?iso-8859-1?Q?9k6K+rCAwTN9qkvfS0NNDMEqkurBQcq3XyVyBIzK4awFzd8CECDX6RU3nL?= =?iso-8859-1?Q?GQNNFKVafn3q4kJxWT0pYmWwT6MtexpZqhOumjeCRCZQpxXiYmnXrP3CvT?= =?iso-8859-1?Q?EqfBo/UH59x+IReVdHgUUEcEtuse4PoO7rd7zDr53ckYSQRqxM2IGfUIIk?= =?iso-8859-1?Q?24gOk++6A8i31ykOrQai68ggaklaxcK0YVWpS0IJY6IZeTwFMPGR+m6w+6?= =?iso-8859-1?Q?Xf1Xjf/yvQrIyZUwPx6Ed9pGwmTS45D6/XqsLLXyyr6pYbd2SrpT0gmyhS?= =?iso-8859-1?Q?w=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:SJ0PR10MB5672.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(376014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?iso-8859-1?Q?sYTHD5FxGXwdqfu3kOF6YCnyRXqmU9D5WLtKHJKD9p8yiB/GpmfFeEfL0X?= =?iso-8859-1?Q?Ltoyy3QNgVBWfcZw+3qTejxPCH3jA2EDwQKasEOcpIndBLknlldUJg1uqU?= =?iso-8859-1?Q?7tS41BsE7oe2qWjL5kSe1mTbo+kbjiZqWRO7v/CDvcD2axFcr6CzCTwFHU?= =?iso-8859-1?Q?bdxE8lG136BEpJOrj1pxxhBcEwPa5Ff8yJ9liVwSWzDtfPJ4bPAo/impVz?= =?iso-8859-1?Q?kbVvp6YmQm9hzbo5AJFXDyqKQrS/m/SQ+URcCARtm5IVuDQE31+VY4iBjk?= =?iso-8859-1?Q?W1Xl3kHOPhbU/ijx4iRLNXongESiEdvAaJmgdASa/dW0AE6bINyOzfMCh5?= =?iso-8859-1?Q?DU2ba2FMWXEffW/KGctLsYlM8B2/ep34VKFgNYP9hmplqoFnyaNz/U16Z4?= =?iso-8859-1?Q?MA9NgUqZbx5V/Wv2KsG1KEw2qthwW+pSlSFEQeZ2OpVYrf+GoWzl3lnXGs?= =?iso-8859-1?Q?GvS+iKNuYJHYo14rRbYOorYTxEBCIyjP9B6j4frEcYuwTfWATdCsgkGx1y?= =?iso-8859-1?Q?e2PMr2Sl4X6VGR3qzHkKwt8U4Ol3IsmFiEVcbyec0JXClld5ctmU04isvm?= =?iso-8859-1?Q?SmysEeJn735oPYOa5muucyyu5vUIpy4ajbpZJRWJHk26D9TZNtYZ/iOB81?= =?iso-8859-1?Q?POPAaawbnb0sSjZOxrIzwXriJDfQyzedO8EUO+LyrxaU192KQjIBdje76O?= =?iso-8859-1?Q?FtDQtzP8W2fD60VPnuEXSKy+QW9Md4GE7wUP9TNVtnMWS4S2n7lU//KJE0?= =?iso-8859-1?Q?OZgcqNdrtzzqRgk5H82bZioDPdxohpSHzWRzK3nIB9+nkHyxa9O3CGGW+C?= =?iso-8859-1?Q?ghQ/81O8BUeklUKBJjpcaK/Ksen0JTOcMUoDbFU7MuWU8QYuwbm6pyOrU0?= =?iso-8859-1?Q?TFX+rPCY8PcQ08AcpGbrLJeTJXmazfJrdq1Tm3SaLqLzdeIxQoN3aPiW+E?= =?iso-8859-1?Q?gAnZnucsXz0A1yojmtfgdtnut5/ib7U/s+KKXp/fYUGBQEMuE2Q6fk3iYJ?= =?iso-8859-1?Q?a9e5StF1NkWfFrjyhSR3qg2Fbvar8B5uS1XucH+dSSXaSPF4KYJe2f0+kA?= =?iso-8859-1?Q?lQwd7kBOavLod4OH4PfFKnpGRDwO/eK+UDR2FhJK3rdDnYNZQW5ZRwoLNR?= =?iso-8859-1?Q?zpQtzEIfXdAVD20ogNZFCP2rkSmLC8hDT+EQm13LBos6TYstBycZTm9Xth?= =?iso-8859-1?Q?K0BBJe/w9e7NrUMk0yNk7sdQz1f8fOZ+iFuOiUOc2DuGXU4CPl4ANc2OJ9?= =?iso-8859-1?Q?hk1sfSK/saPicLGYNFZuCNKYMGVlb+uRZK/2Xcb0oDHI7EW2CefPEnE2kr?= =?iso-8859-1?Q?CbFc4UXnwUiD9vd789wKv921vVGHf3N+qcnIpTHbITMDTPzvwT7gPxmrK1?= =?iso-8859-1?Q?C4C+j4LeHvvRIbBgth2ICjfUMqbnl9K1JM+ABtWOtmRdTOBoSuU2StrLqW?= =?iso-8859-1?Q?mnPRQdqkDh1Ph5/1reHJusM5D2LaG5BkfLu6dkjjTBwfpQBg1YCj8HZijN?= =?iso-8859-1?Q?mRjTzogvylccYuBNgzPVaz/6L3J8f8S1ppfo7iRKzbXwbprULM9d6Zedn4?= =?iso-8859-1?Q?sw/88W94Xx6eL8AS0gqpi8R4TU/aUjwxIbVc6xfGvZURaP7N2VWyJu4e0c?= =?iso-8859-1?Q?N9OAaKZy9TMiB4WG+ZkdrvAGa+neOPDGpP0n6dtoQprItHNGJP7Mcd8Q?= =?iso-8859-1?Q?=3D=3D?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 98421c21-5cfc-4110-4c5a-08ddde74892c X-MS-Exchange-CrossTenant-AuthSource: SJ0PR10MB5672.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Aug 2025 16:30:25.7800 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: BvL97gSgyJYW1pwuImA/i+YfXR9ypEBTmtR5NtlJb8/+btHdSzKiRSTih+Bh+eCXCQbkCVtJftNHIozyDIjJGaKVomKnA1UhQ6yEDY7N5jE= X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR10MB6311 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-08-18_05,2025-08-14_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 mlxscore=0 suspectscore=0 adultscore=0 bulkscore=0 mlxlogscore=999 phishscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2507300000 definitions=main-2508180154 X-Proofpoint-GUID: C9Ei3wAyc2XEKdMrR0DkJHE1tKH0B9Vx X-Proofpoint-ORIG-GUID: C9Ei3wAyc2XEKdMrR0DkJHE1tKH0B9Vx X-Authority-Analysis: v=2.4 cv=G4wcE8k5 c=1 sm=1 tr=0 ts=68a35525 b=1 cx=c_pps a=WeWmnZmh0fydH62SvGsd2A==:117 a=WeWmnZmh0fydH62SvGsd2A==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=z/mQ4Ysz8XfWz/Q5cLBRGdckG28=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=wKuvFiaSGQ0qltdbU6+NXLB8nM8=:19 a=Ol13hO9ccFRV9qXi2t6ftBPywas=:19 a=xqWC_Br6kY4A:10 a=8nJEP1OIZ-IA:10 a=2OwXVqhp2XgA:10 a=GoEa3M9JfhUA:10 a=yPCof4ZbAAAA:8 a=t3O1JwCZcpqTYZ5jnqcA:9 a=3ZKOabzyN94A:10 a=wPNLvfGTeEIA:10 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwODE4MDE1NCBTYWx0ZWRfXy7CNL75NNOG5 aSc5BqZUJPrq6Cxm1ySDerqEDCAB4Vh0g3Vy8n9QqxF0QChrVBD8oJ1uKQMFEmIA6XEg6lErb8i FozRU8zhp+9gOL41HFML+KwevV+m3Har1N5/W7qHJXMhHKr/C2u6X8eMwjrRiJ+DTT9mlIOCbyb nu1VzcNFN/GW0anPQfZ/JeJD6A8G6SKZdibULQA2XxDgbekSUuQu/bUAR8KYQQfiltmGDS9r4f+ ej7yvk9g4UEfufgVaIiAVhKUE2ELTcvSiE3QFqGCjshn07RrsYhksoWSRDO6MwzxFsyOlVAFND9 HwRWFtE6tE+y4JAIvyEr0MVO/Tp6wWpJEafcVqNjrOCMAVpTNPoSRWVgMzb9z/u8HioOmdfWQCk Woc30nhZdgIX4spPI9x4bofSNaWinRdFk40oMja/Bjk0QgStlpD4/jNcvVVu+3rr1zwSm/cm Per discussion we are going to address this by somehow marking these cases of probe specifications (wildcard instructions) to not consider a failure to attach the probe as an error. Specifically probing a given instruction and failing to attach should always remain an error. On Mon, Aug 11, 2025 at 06:13:07PM -0400, Kris Van Hees wrote: > On Mon, Aug 11, 2025 at 04:52:43PM -0400, Eugene Loh wrote: > > On 8/11/25 13:54, Kris Van Hees wrote: > > > > > On Tue, Jun 10, 2025 at 05:10:42PM -0400, eugene.loh@oracle.com wrote: > > > > From: Eugene Loh > > > > > > > > New compilers emit autiasp instructions much more liberally. > > > > A test like test/unittest/pid/tst.entry_off0.sh, which tries > > > > to put a probe on each instruction, may fail. > > > > > > > > Signed-off-by: Eugene Loh > > > > --- > > > > libdtrace/dt_pid.c | 23 +++++++++++++++++------ > > > > 1 file changed, 17 insertions(+), 6 deletions(-) > > > > > > > > diff --git a/libdtrace/dt_pid.c b/libdtrace/dt_pid.c > > > > index e2d4e540d..833e9b647 100644 > > > > --- a/libdtrace/dt_pid.c > > > > +++ b/libdtrace/dt_pid.c > > > > @@ -279,12 +279,17 @@ dt_pid_per_sym(dt_pid_probe_t *pp, const GElf_Sym *symp, const char *func) > > > > nmatches++; > > > > } else if (glob) { > > > > -#if defined(__amd64) > > > > /* > > > > - * We need to step through the instructions to find their > > > > - * offsets. This is difficult on x86, which has variable > > > > - * instruction lengths. We invoke the disassembler in > > > > - * libopcodes. > > > > + * We need the instructions for two reasons: > > > > + * = On x86, instructions have varying lengths. So, > > > > + * to step through the instructions, we need to > > > > + * disassemble them to know what they are. > > > > + * We invoke the disassembler in libopcodes. > > > > + * (On ARM, we step through 4 bytes at a time.) > > > > + * = On both x86 and arm, we want to skip certain > > > > + * instructions. So, again, we need to know what they are. > > > > + */ > > > > + /* > > > > * > > > > * We look for the Elf pointer. It is already stored in > > > > * file_elf in file_info_t, but getting it back over here > > > > @@ -298,7 +303,6 @@ dt_pid_per_sym(dt_pid_probe_t *pp, const GElf_Sym *symp, const char *func) > > > > GElf_Shdr shdr; > > > > Elf_Data *data; > > > > size_t shstrndx, off; > > > > - disassembler_ftype disasm; > > > > /* Set things up. */ > > > > fd = open(pp->dpp_fname, O_RDONLY); > > > > @@ -344,12 +348,14 @@ dt_pid_per_sym(dt_pid_probe_t *pp, const GElf_Sym *symp, const char *func) > > > > /* Get the instructions. */ > > > > data = elf_getdata(scn, NULL); > > > > +#if defined(__amd64) > > > > /* > > > > * "Disassemble" instructions just to get the offsets. > > > > * > > > > * Unfortunately, libopcodes's disassembler() has a different > > > > * interface in binutils versions before 2.29. > > > > */ > > > > + disassembler_ftype disasm; > > > > #if defined(HAVE_DIS1) == defined(HAVE_DIS4) > > > > #error expect disassembler() to have 1 or else 4 arguments > > > > #endif > > > > @@ -390,6 +396,11 @@ dt_pid_per_sym(dt_pid_probe_t *pp, const GElf_Sym *symp, const char *func) > > > > /* Newer kernels do not allow uprobes on "hlt" instructions. */ > > > > if ((unsigned int)disasm_info.buffer[off] == 0xf4) > > > > continue; > > > > +#else > > > > + /* On ARM, we cannot place uprobes on "autiasp" instructions. */ > > > > + if (*((unsigned int *)(data->d_buf + (sym.st_value + off - shdr.sh_addr))) > > > > + == 0xd50323bf) > > > Are there symbolic names we can use here? From an include file concerning > > > opcodes or (worst case) define one ourselves. From the comment, I can assume > > > that the 32-bit hex value you give must be that instruction. But is it an > > > actual 4-byte instruction without any values taht can be set for different > > > uses, etc? Perhaps a define and a comment explaining the value might be > > > useful here. > > > > > > And perhaps do the same for the 'hlt' x86 instruction mentioned above it? > > > > Quite frankly, I'm not familiar with these instructions, and the situation > > is getting worse.  There is another x86 instruction prefix that causes a > > problem and needs to be added -- some "multi-byte nop 0x66 0x66" thing. > > > > I'm tempted to go another route.  Instead of building a list of hlt, > > autiasp, etc., just exclude the ones that don't work.  That is, if I ask for > > pid$pid:$mod:$fun:*, silently ignore the offsets that don't work. > > > > If I remember correctly, a challenge with this approach is that you don't > > know until later that a particular offset will be a problem. Each offset > > would entail an extra runtime check.  That seems unfortunate (and > > unnecessary, if one could know in advance which offsets are okay), but maybe > > it's not such a big deal if you have a lot of probes anyhow. > > > > Anyhow, I don't know these instruction sets.  It might be nice to have a > > solution that does not require specific knowledge of instruction sets (and > > other info). > > Unfortunately, the only source for this information is currently found here > (for arm64): > arch/arm64/kernel/probes/decode-insn.c function arm_probe_decode_insn > > (for x86_64): > arch/x86/kernel/uprobes.c function arch_uprobe_analyze_insn > > So yes, um, good luck. Interestingly, the arm64 case seems to be easier to > handle than the x86_64 case, yet we do not seem to run into issues on the > x86_64 side as much, probably because the unsupported cases are sufficiently > rare in code. > > Trial and error ahead of time is going to be expensive. But we could see about > adding some flag to a probe program that marks it as "ignore any failures for > enabling any of the matching probes". Also, it would be worth looking at > whether there is a form of multiprobe support for uprobes in BPF so that we > can get away with a single program being attached to all the probes (saves > memory). But that again would need to be able to ignore attaching to any > instructions that cannot be supported. Not sure if you can do that. > > > > > + continue; > > > > #endif > > > > snprintf(offstr, sizeof(offstr), "%lx", off); > > > > -- > > > > 2.43.5 > > > >