From patchwork Wed May 19 10:47:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Naveen N. Rao" X-Patchwork-Id: 1480840 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=112.213.38.117; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256 header.s=pp1 header.b=mfBeOBwr; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4FlV5K2jLlz9sXM for ; Wed, 19 May 2021 20:50:29 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4FlV5K1nbWz3cGd for ; Wed, 19 May 2021 20:50:29 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256 header.s=pp1 header.b=mfBeOBwr; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=linux.vnet.ibm.com (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=naveen.n.rao@linux.vnet.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256 header.s=pp1 header.b=mfBeOBwr; dkim-atps=neutral Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4FlV2Y6HxKz3068 for ; Wed, 19 May 2021 20:48:05 +1000 (AEST) Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 14JAhYFv038721; Wed, 19 May 2021 06:47:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=n72zeEhlfmLyVDF+mvHpIAVNMFr/sI9GKBbqisuuxNI=; b=mfBeOBwrNcGTZTFpby5xTHhBm87NSH1vf0wYtKVTlKzT0TZnPwRCsvtRdrmv8TrGuEt4 W3FQDmHIP80KQNXvvU2dRNyytBwH5bIl2Ldu3GfPLXzbsUdAvYEAJdvV9vMN9FQhy2mW cyeJgv6CPrXmP/AhbLrggzaw4nbmxpe08MAOR2IldiCroOXlwpa1k1MAYP578o7xPCz+ 1GIbAEtHFx1Wkev2GdpMN8hQEV7iy5cyCBaIfExS9vrR7GkxNPdlfvaxKRP61Uw3k84Z jdsIUFDbQj8j0vqsx+OuJTPb8RBdW4vme2ZUSJqVwZg8NYmRD3Og9ajhsJIiwJIYpbrF 7A== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 38n0sp8rrc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 19 May 2021 06:47:52 -0400 Received: from m0098409.ppops.net (m0098409.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 14JAhoKd039324; Wed, 19 May 2021 06:47:52 -0400 Received: from ppma03fra.de.ibm.com (6b.4a.5195.ip4.static.sl-reverse.com [149.81.74.107]) by mx0a-001b2d01.pphosted.com with ESMTP id 38n0sp8rqb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 19 May 2021 06:47:52 -0400 Received: from pps.filterd (ppma03fra.de.ibm.com [127.0.0.1]) by ppma03fra.de.ibm.com (8.16.0.43/8.16.0.43) with SMTP id 14JASPQ6029796; Wed, 19 May 2021 10:47:49 GMT Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by ppma03fra.de.ibm.com with ESMTP id 38j5x894dt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 19 May 2021 10:47:49 +0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 14JAllwg16712066 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 19 May 2021 10:47:47 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 431BAA404D; Wed, 19 May 2021 10:47:47 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 50FB1A4040; Wed, 19 May 2021 10:47:45 +0000 (GMT) Received: from naverao1-tp.in.ibm.com (unknown [9.85.72.228]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 19 May 2021 10:47:45 +0000 (GMT) From: "Naveen N. Rao" To: Michael Ellerman , Christophe Leroy , Jordan Niethe Subject: [PATCH 5/5] powerpc/kprobes: Warn if instruction patching failed Date: Wed, 19 May 2021 16:17:21 +0530 Message-Id: <18d7b1309f938c08ce07738100932b551bdd3a52.1621416666.git.naveen.n.rao@linux.vnet.ibm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: References: MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: yHbHOP_Zy5g3pIrVmUfY3Lr-ZrL743qe X-Proofpoint-ORIG-GUID: M5xa1Sf0YOzOuzmlWtf6aOTBRv2PHa0W X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391, 18.0.761 definitions=2021-05-19_04:2021-05-19, 2021-05-19 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 malwarescore=0 priorityscore=1501 lowpriorityscore=0 phishscore=0 impostorscore=0 bulkscore=0 adultscore=0 spamscore=0 clxscore=1015 suspectscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2105190072 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" When arming and disarming probes, we currently assume that instruction patching can never fail, and don't have a mechanism to surface errors. Add a warning in case instruction patching ever fails. Signed-off-by: Naveen N. Rao --- arch/powerpc/kernel/kprobes.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 7195162362941f..e0190e75a221eb 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -158,13 +158,13 @@ NOKPROBE_SYMBOL(arch_prepare_kprobe); void arch_arm_kprobe(struct kprobe *p) { - patch_instruction((struct ppc_inst *)p->addr, ppc_inst(BREAKPOINT_INSTRUCTION)); + WARN_ON_ONCE(patch_instruction((struct ppc_inst *)p->addr, ppc_inst(BREAKPOINT_INSTRUCTION))); } NOKPROBE_SYMBOL(arch_arm_kprobe); void arch_disarm_kprobe(struct kprobe *p) { - patch_instruction((struct ppc_inst *)p->addr, ppc_inst(p->opcode)); + WARN_ON_ONCE(patch_instruction((struct ppc_inst *)p->addr, ppc_inst(p->opcode))); } NOKPROBE_SYMBOL(arch_disarm_kprobe);