From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3003213-1520295974-2-13097766260337856283 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.249, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, UNPARSEABLE_RELAY 0.001, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='com', MailFrom='org' X-Spam-charsets: X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1520295973; b=bl9I3UQxIN40A/09vgUAOUTpXDMzyVkip8baLRPbm/MvjwV NUXCsBqMgt2VS1/8pr5mSMm3aMk9AvKcAIEsnSRQ7aPO6hsL+BkRHefHl58idnTW VLTtczGAY62bZKZPK0vToegBrmT3ZhaZrfN7168XLR20kuXwfDtQ9TUfpYqi/dHt XiGooz3fvq0nK6Ioy8Yc7jrtj+JKLWwarjp9yxTWT7Z8R3N0YbNuQOquZ4ZjHmsI RvttjN+agyIGeZKALjksyiyRY4jJ+FWgyyX/y83eUBbuxoQ7+B8yUcY0SCkVdqE4 NWhFmd/68MD1fssEls6z9ivxE21odeb02UcnOYQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:subject:date:message-id :in-reply-to:references:sender:list-id; s=arctest; t=1520295973; bh=yiexmfzFJCZaFPVZUdV7YyqgR8uYFnW/1Ktuxgpja4c=; b=MaP+AAAKkmzF wj2Ht+oYFuYTTpad5qKBc57TEMpq9vM+AA38trIUhPaffB0KLh86qGwR3CkdhPzW Ax+91+FqzaXtyyRpetldsgoOq8Sjli1gwi6STu4YlpITwIvagyOx4LfDYoMkZa7J zM0LljiJ6J7h2VvDI7IG/DH9PV6AkZ15zH6gdKXcMcvqrSZMWBAVQJqbH5/hLywD nnyubhEhqVJaJSrlcSwhzNnrpeMdiS6Wz8m3NLUABFFFqKqzEy/pIpKv8egkJAEA c8po8TL5xMV5/jwPOgX+QEO+4W+CZZzMkc7zH/nUM2PoRoASEWrChlAdT5kliXgY ewBo2TxmUw== ARC-Authentication-Results: i=1; mx3.messagingengine.com; arc=none (no signatures found); dkim=pass (2048-bit rsa key sha256) header.d=oracle.com header.i=@oracle.com header.b=SckJ2e1o x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=corp-2017-10-26; dmarc=pass (p=none,has-list-id=yes,d=none) header.from=oracle.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-category=clean score=0 state=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=oracle.com header.result=pass header_is_org_domain=yes Authentication-Results: mx3.messagingengine.com; arc=none (no signatures found); dkim=pass (2048-bit rsa key sha256) header.d=oracle.com header.i=@oracle.com header.b=SckJ2e1o x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=corp-2017-10-26; dmarc=pass (p=none,has-list-id=yes,d=none) header.from=oracle.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-category=clean score=0 state=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=oracle.com header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932930AbeCFA0L (ORCPT ); Mon, 5 Mar 2018 19:26:11 -0500 Received: from aserp2130.oracle.com ([141.146.126.79]:34758 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932926AbeCFA0K (ORCPT ); Mon, 5 Mar 2018 19:26:10 -0500 From: Pavel Tatashin To: steven.sistare@oracle.com, daniel.m.jordan@oracle.com, linux-kernel@vger.kernel.org, Alexander.Levin@microsoft.com, dan.j.williams@intel.com, sathyanarayanan.kuppuswamy@intel.com, pankaj.laxminarayan.bharadiya@intel.com, akuster@mvista.com, cminyard@mvista.com, pasha.tatashin@oracle.com, gregkh@linuxfoundation.org, stable@vger.kernel.org Subject: [PATCH 4.1 09/65] x86/mm, sched/core: Turn off IRQs in switch_mm() Date: Mon, 5 Mar 2018 19:24:42 -0500 Message-Id: <20180306002538.1761-10-pasha.tatashin@oracle.com> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180306002538.1761-1-pasha.tatashin@oracle.com> References: <20180306002538.1761-1-pasha.tatashin@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8823 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=930 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1803060003 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: From: Andy Lutomirski commit 078194f8e9fe3cf54c8fd8bded48a1db5bd8eb8a upstream. Potential races between switch_mm() and TLB-flush or LDT-flush IPIs could be very messy. AFAICT the code is currently okay, whether by accident or by careful design, but enabling PCID will make it considerably more complicated and will no longer be obviously safe. Fix it with a big hammer: run switch_mm() with IRQs off. To avoid a performance hit in the scheduler, we take advantage of our knowledge that the scheduler already has IRQs disabled when it calls switch_mm(). Signed-off-by: Andy Lutomirski Reviewed-by: Borislav Petkov Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/f19baf759693c9dcae64bbff76189db77cb13398.1461688545.git.luto@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman (cherry picked from commit 4ead44fd2525ed97e5362a806d312a0e3b0ea445) Signed-off-by: Pavel Tatashin Conflicts: arch/x86/include/asm/mmu_context.h --- arch/x86/include/asm/mmu_context.h | 4 ++++ arch/x86/mm/tlb.c | 10 ++++++++++ 2 files changed, 14 insertions(+) diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index 375fafccb32c..2bf4bae1c65e 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -95,6 +95,10 @@ static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) extern void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk); +extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk); +#define switch_mm_irqs_off switch_mm_irqs_off + #define activate_mm(prev, next) \ do { \ paravirt_activate_mm((prev), (next)); \ diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 40c640980720..4ce6569ad963 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -63,6 +63,16 @@ EXPORT_SYMBOL_GPL(leave_mm); void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) +{ + unsigned long flags; + + local_irq_save(flags); + switch_mm_irqs_off(prev, next, tsk); + local_irq_restore(flags); +} + +void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk) { unsigned cpu = smp_processor_id(); -- 2.16.2