From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 704A97DF8D for ; Wed, 6 Jun 2018 08:35:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932520AbeFFIeV (ORCPT ); Wed, 6 Jun 2018 04:34:21 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:40558 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932599AbeFFIeU (ORCPT ); Wed, 6 Jun 2018 04:34:20 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w568TbTQ142061 for ; Wed, 6 Jun 2018 04:34:19 -0400 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0b-001b2d01.pphosted.com with ESMTP id 2je96j7dgn-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 06 Jun 2018 04:34:19 -0400 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 6 Jun 2018 09:34:14 +0100 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w568YD4O33161348 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 6 Jun 2018 08:34:13 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7337BA4051; Wed, 6 Jun 2018 09:25:15 +0100 (BST) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id ACAC8A4040; Wed, 6 Jun 2018 09:25:12 +0100 (BST) Received: from bangoria.in.ibm.com (unknown [9.124.31.17]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 6 Jun 2018 09:25:12 +0100 (BST) From: Ravi Bangoria To: oleg@redhat.com, srikar@linux.vnet.ibm.com, rostedt@goodmis.org, mhiramat@kernel.org Cc: peterz@infradead.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org, linux-kernel@vger.kernel.org, corbet@lwn.net, linux-doc@vger.kernel.org, ananth@linux.vnet.ibm.com, alexis.berlemont@gmail.com, naveen.n.rao@linux.vnet.ibm.com, Ravi Bangoria Subject: [PATCH 5/7] Uprobes/sdt: Prevent multiple reference counter for same uprobe Date: Wed, 6 Jun 2018 14:03:42 +0530 X-Mailer: git-send-email 2.14.4 In-Reply-To: <20180606083344.31320-1-ravi.bangoria@linux.ibm.com> References: <20180606083344.31320-1-ravi.bangoria@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18060608-0012-0000-0000-0000027BA8CB X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18060608-0013-0000-0000-000020ACB1F9 Message-Id: <20180606083344.31320-6-ravi.bangoria@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-06-06_03:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1805220000 definitions=main-1806060098 Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Even if we don't allow to create same uprobe with different reference counter offset via trace_uprobe, user can still create such uprobes by creating one uprobe using trace_uprobe and other by directly calling uprobe_register() from kernel module. Prevent such scenarios. Note that, we are restricting user to not use both ways (trace_uprobe and kernel module) simultaneously. Ex, User can not trace single uprobe (with reference counter) simultaneously with Systemtap and perf at the same time. Signed-off-by: Ravi Bangoria --- kernel/events/uprobes.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 279c8fc..5e07f99 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -526,6 +526,12 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset, cur_uprobe = insert_uprobe(uprobe); /* a uprobe exists for this inode:offset combination */ if (cur_uprobe) { + if (cur_uprobe->ref_ctr_offset != uprobe->ref_ctr_offset) { + pr_warn("Err: Reference counter mismatch.\n"); + put_uprobe(cur_uprobe); + kfree(uprobe); + return ERR_PTR(-EINVAL); + } kfree(uprobe); uprobe = cur_uprobe; } @@ -1184,6 +1190,9 @@ static int __uprobe_register(struct inode *inode, loff_t offset, uprobe = alloc_uprobe(inode, offset, ref_ctr_offset); if (!uprobe) return -ENOMEM; + if (IS_ERR(uprobe)) + return PTR_ERR(uprobe); + /* * We can race with uprobe_unregister()->delete_uprobe(). * Check uprobe_is_active() and retry if it is false. -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html