From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0F9EC433DF for ; Fri, 29 May 2020 05:47:55 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1F52A208B8 for ; Fri, 29 May 2020 05:47:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1F52A208B8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49YDB13YNqzDqcY for ; Fri, 29 May 2020 15:47:53 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) 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 49YD3P16fHzDqfZ for ; Fri, 29 May 2020 15:42:08 +1000 (AEST) Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 04T5VFVf042388; Fri, 29 May 2020 01:41:59 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 31as1mvc42-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 29 May 2020 01:41:59 -0400 Received: from m0098413.ppops.net (m0098413.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 04T5ZJ1r054258; Fri, 29 May 2020 01:41:58 -0400 Received: from ppma03wdc.us.ibm.com (ba.79.3fa9.ip4.static.sl-reverse.com [169.63.121.186]) by mx0b-001b2d01.pphosted.com with ESMTP id 31as1mvc3u-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 29 May 2020 01:41:58 -0400 Received: from pps.filterd (ppma03wdc.us.ibm.com [127.0.0.1]) by ppma03wdc.us.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 04T5eFuv022673; Fri, 29 May 2020 05:41:58 GMT Received: from b01cxnp22035.gho.pok.ibm.com (b01cxnp22035.gho.pok.ibm.com [9.57.198.25]) by ppma03wdc.us.ibm.com with ESMTP id 316uf9sh1u-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 29 May 2020 05:41:58 +0000 Received: from b01ledav002.gho.pok.ibm.com (b01ledav002.gho.pok.ibm.com [9.57.199.107]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 04T5fvVI44892580 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 29 May 2020 05:41:57 GMT Received: from b01ledav002.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7615A124055; Fri, 29 May 2020 05:41:57 +0000 (GMT) Received: from b01ledav002.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2D497124053; Fri, 29 May 2020 05:41:55 +0000 (GMT) Received: from skywalker.ibmuc.com (unknown [9.85.84.128]) by b01ledav002.gho.pok.ibm.com (Postfix) with ESMTP; Fri, 29 May 2020 05:41:54 +0000 (GMT) From: "Aneesh Kumar K.V" To: linuxppc-dev@lists.ozlabs.org, mpe@ellerman.id.au, linux-nvdimm@lists.01.org, dan.j.williams@intel.com Subject: [RFC PATCH 1/2] libnvdimm: Add prctl control for disabling synchronous fault support. Date: Fri, 29 May 2020 11:11:39 +0530 Message-Id: <20200529054141.156384-1-aneesh.kumar@linux.ibm.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216, 18.0.687 definitions=2020-05-29_01:2020-05-28, 2020-05-29 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 adultscore=0 mlxscore=0 mlxlogscore=999 lowpriorityscore=0 clxscore=1015 suspectscore=0 priorityscore=1501 spamscore=0 malwarescore=0 impostorscore=0 cotscore=-2147483648 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2005290038 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" , oohall@gmail.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" With POWER10, architecture is adding new pmem flush and sync instructions. The kernel should prevent the usage of MAP_SYNC if applications are not using the new instructions on newer hardware. This patch adds a prctl option MAP_SYNC_ENABLE that can be used to enable the usage of MAP_SYNC. The kernel config option is added to allow the user to control whether MAP_SYNC should be enabled by default or not. Signed-off-by: Aneesh Kumar K.V --- include/linux/sched/coredump.h | 13 ++++++++++--- include/uapi/linux/prctl.h | 3 +++ kernel/fork.c | 8 +++++++- kernel/sys.c | 18 ++++++++++++++++++ mm/Kconfig | 3 +++ mm/mmap.c | 4 ++++ 6 files changed, 45 insertions(+), 4 deletions(-) diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h index ecdc6542070f..9ba6b3d5f991 100644 --- a/include/linux/sched/coredump.h +++ b/include/linux/sched/coredump.h @@ -72,9 +72,16 @@ static inline int get_dumpable(struct mm_struct *mm) #define MMF_DISABLE_THP 24 /* disable THP for all VMAs */ #define MMF_OOM_VICTIM 25 /* mm is the oom victim */ #define MMF_OOM_REAP_QUEUED 26 /* mm was queued for oom_reaper */ -#define MMF_DISABLE_THP_MASK (1 << MMF_DISABLE_THP) +#define MMF_DISABLE_MAP_SYNC 27 /* disable THP for all VMAs */ +#define MMF_DISABLE_THP_MASK (1 << MMF_DISABLE_THP) +#define MMF_DISABLE_MAP_SYNC_MASK (1 << MMF_DISABLE_MAP_SYNC) -#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\ - MMF_DISABLE_THP_MASK) +#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK | \ + MMF_DISABLE_THP_MASK | MMF_DISABLE_MAP_SYNC_MASK) + +static inline bool map_sync_enabled(struct mm_struct *mm) +{ + return !(mm->flags & MMF_DISABLE_MAP_SYNC_MASK); +} #endif /* _LINUX_SCHED_COREDUMP_H */ diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index 07b4f8131e36..ee4cde32d5cf 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -238,4 +238,7 @@ struct prctl_mm_map { #define PR_SET_IO_FLUSHER 57 #define PR_GET_IO_FLUSHER 58 +#define PR_SET_MAP_SYNC_ENABLE 59 +#define PR_GET_MAP_SYNC_ENABLE 60 + #endif /* _LINUX_PRCTL_H */ diff --git a/kernel/fork.c b/kernel/fork.c index 8c700f881d92..d5a9a363e81e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -963,6 +963,12 @@ __cacheline_aligned_in_smp DEFINE_SPINLOCK(mmlist_lock); static unsigned long default_dump_filter = MMF_DUMP_FILTER_DEFAULT; +#ifdef CONFIG_ARCH_MAP_SYNC_DISABLE +unsigned long default_map_sync_mask = MMF_DISABLE_MAP_SYNC_MASK; +#else +unsigned long default_map_sync_mask = 0; +#endif + static int __init coredump_filter_setup(char *s) { default_dump_filter = @@ -1039,7 +1045,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, mm->flags = current->mm->flags & MMF_INIT_MASK; mm->def_flags = current->mm->def_flags & VM_INIT_DEF_MASK; } else { - mm->flags = default_dump_filter; + mm->flags = default_dump_filter | default_map_sync_mask; mm->def_flags = 0; } diff --git a/kernel/sys.c b/kernel/sys.c index d325f3ab624a..f6127cf4128b 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2450,6 +2450,24 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, clear_bit(MMF_DISABLE_THP, &me->mm->flags); up_write(&me->mm->mmap_sem); break; + + case PR_GET_MAP_SYNC_ENABLE: + if (arg2 || arg3 || arg4 || arg5) + return -EINVAL; + error = !test_bit(MMF_DISABLE_MAP_SYNC, &me->mm->flags); + break; + case PR_SET_MAP_SYNC_ENABLE: + if (arg3 || arg4 || arg5) + return -EINVAL; + if (down_write_killable(&me->mm->mmap_sem)) + return -EINTR; + if (arg2) + clear_bit(MMF_DISABLE_MAP_SYNC, &me->mm->flags); + else + set_bit(MMF_DISABLE_MAP_SYNC, &me->mm->flags); + up_write(&me->mm->mmap_sem); + break; + case PR_MPX_ENABLE_MANAGEMENT: case PR_MPX_DISABLE_MANAGEMENT: /* No longer implemented: */ diff --git a/mm/Kconfig b/mm/Kconfig index c1acc34c1c35..38fd7cfbfca8 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -867,4 +867,7 @@ config ARCH_HAS_HUGEPD config MAPPING_DIRTY_HELPERS bool +config ARCH_MAP_SYNC_DISABLE + bool + endmenu diff --git a/mm/mmap.c b/mm/mmap.c index f609e9ec4a25..613e5894f178 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1464,6 +1464,10 @@ unsigned long do_mmap(struct file *file, unsigned long addr, case MAP_SHARED_VALIDATE: if (flags & ~flags_mask) return -EOPNOTSUPP; + + if ((flags & MAP_SYNC) && !map_sync_enabled(mm)) + return -EOPNOTSUPP; + if (prot & PROT_WRITE) { if (!(file->f_mode & FMODE_WRITE)) return -EACCES; -- 2.26.2