From patchwork Wed May 15 09:45:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aneesh Kumar K V X-Patchwork-Id: 1099914 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 453qTp6YmHz9sNf for ; Wed, 15 May 2019 19:47:26 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 453qTp5fdfzDqSv for ; Wed, 15 May 2019 19:47:26 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=linux.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=aneesh.kumar@linux.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from mx0a-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 453qRj4s4hzDqS2 for ; Wed, 15 May 2019 19:45:37 +1000 (AEST) Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4F9gkRI069870 for ; Wed, 15 May 2019 05:45:32 -0400 Received: from e34.co.us.ibm.com (e34.co.us.ibm.com [32.97.110.152]) by mx0b-001b2d01.pphosted.com with ESMTP id 2sgg7fgkxe-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 15 May 2019 05:45:32 -0400 Received: from localhost by e34.co.us.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, 15 May 2019 10:45:29 +0100 Received: from b03ledav001.gho.boulder.ibm.com (b03ledav001.gho.boulder.ibm.com [9.17.130.232]) by b03cxnp08027.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4F9jSPD60293204 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 15 May 2019 09:45:28 GMT Received: from b03ledav001.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BB6436E04E; Wed, 15 May 2019 09:45:28 +0000 (GMT) Received: from b03ledav001.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CED9A6E04C; Wed, 15 May 2019 09:45:26 +0000 (GMT) Received: from skywalker.ibmuc.com (unknown [9.102.19.15]) by b03ledav001.gho.boulder.ibm.com (Postfix) with ESMTP; Wed, 15 May 2019 09:45:26 +0000 (GMT) From: "Aneesh Kumar K.V" To: npiggin@gmail.com, paulus@samba.org, mpe@ellerman.id.au Subject: [PATCH] powerpc/mm: Drop VM_BUG_ON in get_region_id Date: Wed, 15 May 2019 15:15:23 +0530 X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19051509-0016-0000-0000-000009B2A67D X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00011100; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000285; SDB=6.01203605; UDB=6.00631788; IPR=6.00984532; MB=3.00026901; MTD=3.00000008; XFM=3.00000015; UTC=2019-05-15 09:45:31 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19051509-0017-0000-0000-00004339CDF5 Message-Id: <20190515094523.8095-1-aneesh.kumar@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-05-15_06:, , 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=971 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905150063 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: "Aneesh Kumar K.V" , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" We can call get_region_id without validating the ea value. That means with a wrong ea value we hit the BUG as below. kernel BUG at arch/powerpc/include/asm/book3s/64/hash.h:129! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries CPU: 0 PID: 3937 Comm: access_tests Not tainted 5.1.0 .... NIP [c00000000007ba20] do_slb_fault+0x70/0x320 LR [c00000000000896c] data_access_slb_common+0x15c/0x1a0 Fix this by removing the VM_BUG_ON. All callers make sure the returned region id is valid and error out otherwise. Fixes: 0034d395f89d ("powerpc/mm/hash64: Map all the kernel regions in the same 0xc range") Signed-off-by: Aneesh Kumar K.V --- arch/powerpc/include/asm/book3s/64/hash.h | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h index 1d1183048cfd..5486087e64ea 100644 --- a/arch/powerpc/include/asm/book3s/64/hash.h +++ b/arch/powerpc/include/asm/book3s/64/hash.h @@ -122,11 +122,9 @@ static inline int get_region_id(unsigned long ea) if (ea < H_KERN_VIRT_START) return LINEAR_MAP_REGION_ID; - VM_BUG_ON(id != 0xc); BUILD_BUG_ON(NON_LINEAR_REGION_ID(H_VMALLOC_START) != 2); region_id = NON_LINEAR_REGION_ID(ea); - VM_BUG_ON(region_id > VMEMMAP_REGION_ID); return region_id; }