Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752017AbdFUX0s (ORCPT ); Wed, 21 Jun 2017 19:26:48 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:34928 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750986AbdFUX0r (ORCPT ); Wed, 21 Jun 2017 19:26:47 -0400 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) Subject: Re: [PATCH v3 01/11] x86/mm: Don't reenter flush_tlb_func_common() From: Nadav Amit In-Reply-To: Date: Wed, 21 Jun 2017 16:26:43 -0700 Cc: X86 ML , LKML , Borislav Petkov , Linus Torvalds , Andrew Morton , Mel Gorman , "linux-mm@kvack.org" , Rik van Riel , Dave Hansen , Arjan van de Ven , Peter Zijlstra Message-Id: <207CCA52-C1A0-4AEF-BABF-FA6552CFB71F@gmail.com> References: To: Andy Lutomirski X-Mailer: Apple Mail (2.3273) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id v5LNQrXN031209 Content-Length: 1591 Lines: 57 Andy Lutomirski wrote: > index 2a5e851f2035..f06239c6919f 100644 > --- a/arch/x86/mm/tlb.c > +++ b/arch/x86/mm/tlb.c > @@ -208,6 +208,9 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next, > static void flush_tlb_func_common(const struct flush_tlb_info *f, > bool local, enum tlb_flush_reason reason) > { > + /* This code cannot presently handle being reentered. */ > + VM_WARN_ON(!irqs_disabled()); > + > if (this_cpu_read(cpu_tlbstate.state) != TLBSTATE_OK) { > leave_mm(smp_processor_id()); > return; > @@ -313,8 +316,12 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, > info.end = TLB_FLUSH_ALL; > } > > - if (mm == this_cpu_read(cpu_tlbstate.loaded_mm)) > + if (mm == this_cpu_read(cpu_tlbstate.loaded_mm)) { Perhaps you want to add: VM_WARN_ON(irqs_disabled()); here > + local_irq_disable(); > flush_tlb_func_local(&info, TLB_LOCAL_MM_SHOOTDOWN); > + local_irq_enable(); > + } > + > if (cpumask_any_but(mm_cpumask(mm), cpu) < nr_cpu_ids) > flush_tlb_others(mm_cpumask(mm), &info); > put_cpu(); > @@ -370,8 +377,12 @@ void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch) > > int cpu = get_cpu(); > > - if (cpumask_test_cpu(cpu, &batch->cpumask)) > + if (cpumask_test_cpu(cpu, &batch->cpumask)) { and here? > + local_irq_disable(); > flush_tlb_func_local(&info, TLB_LOCAL_SHOOTDOWN); > + local_irq_enable(); > + } > + > if (cpumask_any_but(&batch->cpumask, cpu) < nr_cpu_ids) > flush_tlb_others(&batch->cpumask, &info); > cpumask_clear(&batch->cpumask); > -- > 2.9.4