From patchwork Mon May 8 02:01:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rohan McLure X-Patchwork-Id: 1778211 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.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+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=) Authentication-Results: legolas.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=p0ViEXT0; 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 ECDSA (P-384)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4QF4Rq1cs1z1ymw for ; Mon, 8 May 2023 12:07:19 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4QF4Rq0VjQz3fWb for ; Mon, 8 May 2023 12:07:19 +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=p0ViEXT0; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.ibm.com (client-ip=148.163.158.5; helo=mx0b-001b2d01.pphosted.com; envelope-from=rmclure@linux.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=p0ViEXT0; dkim-atps=neutral Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (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 4QF4Kc4C2Gz3c9K for ; Mon, 8 May 2023 12:01:56 +1000 (AEST) Received: from pps.filterd (m0353725.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3481xK1U010923; Mon, 8 May 2023 02:01:46 GMT 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=+CPAayH10+MkosF6zRsxoGEJ6ehr10JUGfcmDJ0r+ZM=; b=p0ViEXT0Jmb7f2sKXGb6o6QZmk0Deta2IyUObskrDK1Pg3Z1gNEQCGmEwZ0KyVRT321u 284KGE2PuPrCAg4cK44pqZz3Yjpee72CW3sHS9OM7+P/xPoHiX+IENOeuBpiEN34D6Vf M336pp68sJ/dg6pfBreg2g25Z4NGf6F7GB2w6GFmxSxc7idi4J5V2mq9y2In9fbba0aB YUb8EdoD3T96Au3S4v44YAy84ueowfYnxtlKr2FTvtjGhl805YyCi26N97q3N/Bl86QD KINg2bsNWtbxVoejHmDpCrI6lLMWI1swow1WitDYlABtuSumqoKRP2ymxueJ9JAJ4d4m Yg== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3qeqwdg20u-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 08 May 2023 02:01:46 +0000 Received: from m0353725.ppops.net (m0353725.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 348202Lf012767; Mon, 8 May 2023 02:01:45 GMT Received: from ppma04fra.de.ibm.com (6a.4a.5195.ip4.static.sl-reverse.com [149.81.74.106]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3qeqwdg20a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 08 May 2023 02:01:44 +0000 Received: from pps.filterd (ppma04fra.de.ibm.com [127.0.0.1]) by ppma04fra.de.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 3480KKs8006504; Mon, 8 May 2023 02:01:43 GMT Received: from smtprelay05.fra02v.mail.ibm.com ([9.218.2.225]) by ppma04fra.de.ibm.com (PPS) with ESMTPS id 3qdeh6gpjc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 08 May 2023 02:01:43 +0000 Received: from smtpav03.fra02v.mail.ibm.com (smtpav03.fra02v.mail.ibm.com [10.20.54.102]) by smtprelay05.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 34821eRY12714584 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 8 May 2023 02:01:40 GMT Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8CF062004E; Mon, 8 May 2023 02:01:40 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 10C3120040; Mon, 8 May 2023 02:01:40 +0000 (GMT) Received: from ozlabs.au.ibm.com (unknown [9.192.253.14]) by smtpav03.fra02v.mail.ibm.com (Postfix) with ESMTP; Mon, 8 May 2023 02:01:40 +0000 (GMT) Received: from civic.. (haven.au.ibm.com [9.192.254.114]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.au.ibm.com (Postfix) with ESMTPSA id 5CD0C605DC; Mon, 8 May 2023 12:01:35 +1000 (AEST) From: Rohan McLure To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH 08/12] powerpc: Annotate accesses to ipi message flags Date: Mon, 8 May 2023 12:01:16 +1000 Message-Id: <20230508020120.218494-9-rmclure@linux.ibm.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20230508020120.218494-1-rmclure@linux.ibm.com> References: <20230508020120.218494-1-rmclure@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: 7TWjvqK-IPPKTZw4yUk6cOpKGfMa6Jkq X-Proofpoint-GUID: yzdY7YGFNMHMqIlbyPXwGKgXEZGbm9MX X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-05-07_10,2023-05-05_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 impostorscore=0 suspectscore=0 phishscore=0 mlxscore=0 clxscore=1015 spamscore=0 lowpriorityscore=0 adultscore=0 bulkscore=0 malwarescore=0 mlxlogscore=864 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2305080009 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: Rohan McLure , npiggin@gmail.com, arnd@arndb.de Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" IPI message flags are observed and consequently consumed in the smp_ipi_demux_relaxed function, which handles these message sources until it observes none more arriving. Mark the checked loop guard with READ_ONCE, to signal to KCSAN that the read is known to be volatile, and that non-determinism is expected. Signed-off-by: Rohan McLure --- arch/powerpc/kernel/smp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 6b90f10a6c81..00b74d66b771 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -348,7 +348,7 @@ irqreturn_t smp_ipi_demux_relaxed(void) if (all & IPI_MESSAGE(PPC_MSG_NMI_IPI)) nmi_ipi_action(0, NULL); #endif - } while (info->messages); + } while (READ_ONCE(info->messages)); return IRQ_HANDLED; }