From patchwork Thu Jun 8 19:23:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hugh Dickins X-Patchwork-Id: 13272751 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D6CBC7EE2E for ; Thu, 8 Jun 2023 19:24:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236465AbjFHTYT (ORCPT ); Thu, 8 Jun 2023 15:24:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40970 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233419AbjFHTYS (ORCPT ); Thu, 8 Jun 2023 15:24:18 -0400 Received: from mail-yw1-x112e.google.com (mail-yw1-x112e.google.com [IPv6:2607:f8b0:4864:20::112e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EC8D30DA for ; Thu, 8 Jun 2023 12:23:40 -0700 (PDT) Received: by mail-yw1-x112e.google.com with SMTP id 00721157ae682-565a63087e9so9111157b3.2 for ; Thu, 08 Jun 2023 12:23:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1686252220; x=1688844220; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:from:to:cc:subject:date:message-id:reply-to; bh=qDN5tZO3L77JzaZm0GUojeVr1G6nDfqvfBbmKnfTG1k=; b=bsqS2HsoK/j3AkqW2YwOMMKXyawvBNLxJHVA5gOfV85QJu1lSu6OT/EudsU4V/Y2rp SVDrhg0mebSfRzfMSx1MBgwwDrAuWoy9LCmuC/2umX7ttwWByA3dcTWU9wXJ/cBuk8p1 IBLsaSZQWTiGTy2fVfGTVTLpxXSu83YUCgCeShfLhLQEtHAObGCmd/2pMwHoVzhnbL+s R/RqL9aWefb7+V22j+wCoHy3L9k9iU7LsdUzazOEG+iBjRzVfoBnNonp+eUMgHPu99EP wikBPo2R7DnOhGnbBte9FiJ408IVODR7hjXz04IiqDN6B3KGc/TbdicQd+c7pqZBIdYk E3bQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686252220; x=1688844220; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=qDN5tZO3L77JzaZm0GUojeVr1G6nDfqvfBbmKnfTG1k=; b=Gr7xb+hq0yUhsCjyXgzcj/REz7in0oKjlqq/TTIf8o9xuG8/lnoF2zTvbMuGjzr2nC VSFCTylKRApJcF4VSfihdYesyAmVVgTGS/HeuHYlriVyOGeodF/0BqZN4UnQcwMggWhs TS9K+VZtMmfCyawqjqiftaZwU0neSY8GFIQYX5Q+Vijt2bnQfEnkHRo8lCm3M0+HakH5 ISCoLUDWrGnn2KuUI/2HLYAoXjpag72YkMMRkqn+RW/qUAGsqsK90YwwTFVoy+bJeo9g rzxe9FdyWjb1sw1w113SAKs/AGrxFbzP14Ej19GcBYd50Hphetkl798JujS+5iELEmpH /GrQ== X-Gm-Message-State: AC+VfDypgy5KN76XTE4TG+dkQufwR/9NVn0+KP8VuujNvP9olez5aihW veQx8XNoL+Nw4l06VftMLlf4MQ== X-Google-Smtp-Source: ACHHUZ5B2AQmlb0Co/ti6j7UtSZsz6kvSjI4SOSm5MiJUvPHp7lW170oPhZmXl+FiXgmdx/jiLqYOA== X-Received: by 2002:a0d:d843:0:b0:565:8c16:a0e1 with SMTP id a64-20020a0dd843000000b005658c16a0e1mr683325ywe.13.1686252219629; Thu, 08 Jun 2023 12:23:39 -0700 (PDT) Received: from ripple.attlocal.net (172-10-233-147.lightspeed.sntcca.sbcglobal.net. [172.10.233.147]) by smtp.gmail.com with ESMTPSA id j65-20020a0df944000000b00545a08184e0sm102947ywf.112.2023.06.08.12.23.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 08 Jun 2023 12:23:39 -0700 (PDT) Date: Thu, 8 Jun 2023 12:23:35 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@ripple.attlocal.net To: Andrew Morton cc: Mike Kravetz , Mike Rapoport , "Kirill A. Shutemov" , Matthew Wilcox , David Hildenbrand , Suren Baghdasaryan , Qi Zheng , Peter Zijlstra , Russell King , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Greg Ungerer , Michal Simek , Thomas Bogendoerfer , Helge Deller , John David Anglin , "Aneesh Kumar K.V" , Michael Ellerman , Alexandre Ghiti , Palmer Dabbelt , Heiko Carstens , Christian Borntraeger , Claudio Imbrenda , Alexander Gordeev , John Paul Adrian Glaubitz , "David S. Miller" , Chris Zankel , Max Filippov , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v2 12/23] powerpc: allow pte_offset_map[_lock]() to fail In-Reply-To: Message-ID: <54c8b578-ca9-a0f-bfd2-d72976f8d73a@google.com> References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org In rare transient cases, not yet made possible, pte_offset_map() and pte_offset_map_lock() may not find a page table: handle appropriately. Balance successful pte_offset_map() with pte_unmap() where omitted. Signed-off-by: Hugh Dickins --- arch/powerpc/mm/book3s64/hash_tlb.c | 4 ++++ arch/powerpc/mm/book3s64/subpage_prot.c | 2 ++ arch/powerpc/xmon/xmon.c | 5 ++++- 3 files changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/mm/book3s64/hash_tlb.c b/arch/powerpc/mm/book3s64/hash_tlb.c index a64ea0a7ef96..21fcad97ae80 100644 --- a/arch/powerpc/mm/book3s64/hash_tlb.c +++ b/arch/powerpc/mm/book3s64/hash_tlb.c @@ -239,12 +239,16 @@ void flush_hash_table_pmd_range(struct mm_struct *mm, pmd_t *pmd, unsigned long local_irq_save(flags); arch_enter_lazy_mmu_mode(); start_pte = pte_offset_map(pmd, addr); + if (!start_pte) + goto out; for (pte = start_pte; pte < start_pte + PTRS_PER_PTE; pte++) { unsigned long pteval = pte_val(*pte); if (pteval & H_PAGE_HASHPTE) hpte_need_flush(mm, addr, pte, pteval, 0); addr += PAGE_SIZE; } + pte_unmap(start_pte); +out: arch_leave_lazy_mmu_mode(); local_irq_restore(flags); } diff --git a/arch/powerpc/mm/book3s64/subpage_prot.c b/arch/powerpc/mm/book3s64/subpage_prot.c index b75a9fb99599..0dc85556dec5 100644 --- a/arch/powerpc/mm/book3s64/subpage_prot.c +++ b/arch/powerpc/mm/book3s64/subpage_prot.c @@ -71,6 +71,8 @@ static void hpte_flush_range(struct mm_struct *mm, unsigned long addr, if (pmd_none(*pmd)) return; pte = pte_offset_map_lock(mm, pmd, addr, &ptl); + if (!pte) + return; arch_enter_lazy_mmu_mode(); for (; npages > 0; --npages) { pte_update(mm, addr, pte, 0, 0, 0); diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 70c4c59a1a8f..fae747cc57d2 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -3376,12 +3376,15 @@ static void show_pte(unsigned long addr) printf("pmdp @ 0x%px = 0x%016lx\n", pmdp, pmd_val(*pmdp)); ptep = pte_offset_map(pmdp, addr); - if (pte_none(*ptep)) { + if (!ptep || pte_none(*ptep)) { + if (ptep) + pte_unmap(ptep); printf("no valid PTE\n"); return; } format_pte(ptep, pte_val(*ptep)); + pte_unmap(ptep); sync(); __delay(200);