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=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 57D08C3F2D1 for ; Wed, 4 Mar 2020 04:38:58 +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 D089C20842 for ; Wed, 4 Mar 2020 04:38:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=fossix-org.20150623.gappssmtp.com header.i=@fossix-org.20150623.gappssmtp.com header.b="CTy1/m9r" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D089C20842 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=fossix.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48XLk74jMhzDqcY for ; Wed, 4 Mar 2020 15:38:55 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=fossix.org (client-ip=2607:f8b0:4864:20::1043; helo=mail-pj1-x1043.google.com; envelope-from=santosh@fossix.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=fossix.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=fossix-org.20150623.gappssmtp.com header.i=@fossix-org.20150623.gappssmtp.com header.a=rsa-sha256 header.s=20150623 header.b=CTy1/m9r; dkim-atps=neutral Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 48XLY05hQqzDqTp for ; Wed, 4 Mar 2020 15:31:00 +1100 (AEDT) Received: by mail-pj1-x1043.google.com with SMTP id d8so333857pje.4 for ; Tue, 03 Mar 2020 20:31:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fossix-org.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=tkgbxGTiv6piVRKbNX9ksR7st+vRYwUGKl28isP4EyE=; b=CTy1/m9rPRtu5aqcm/g32C39uVkhnCm1CDK1E3MoKc72DOf/N1EKMJIr3pw/5uxWiW aQFZ7PPtcecTMpCikzs89Vk6Cd7zwKeEp2DpEyqvuO1y3m5wQAko5SuBSHZ6oMK7+tcn 7a26kNEeAhSpGcezR6hg1kdf7py+ldhA+suXv45gWVb0/eyHk/EY5R9hwk19TtNozwsE GJTBwKQ/qGSe8dmtUqsZ67daT1R0Zr+wHM041ryjmGcfLt9pUrkl19nF6KQe8NkZOPNT lgtmG8kJFJ5Bb6ZxYNoXUddLIOl7aFVtPx8cQB7Atml4+G/gpweGhOsKVZdU9RXZtdFT wp0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=tkgbxGTiv6piVRKbNX9ksR7st+vRYwUGKl28isP4EyE=; b=Ro4ARtj/XXXkF2owcX8zVzL5XWJmUQsOxJrOyW4OwJi+BS7tfxDVZutK6qRrYYQEPS 4S9qjLJo1pcnRIn4nzYp9UphNrZCKifPNYWyKu66tH3hf9E0vIZhZUG8C0TstKT5R304 QxPsexZwx5nfEatPuqAqrMZmpOXK9VSa7drQxQ9Lpc7dm89sMe/lOvrM6LHFP9cbRQte XjUrymubRa/MZm7BshxWovtikiOVB5Midz8GdhKX9FVTJ6UTtGsFkIobwTWbe5nX6avE RZ9r0P2Im452EaO1j4wO/IkE8BsRbKkgOh0Oq+DkvBRPxdAHBp75wu8ESE6x3+ISVCsG LvyQ== X-Gm-Message-State: ANhLgQ1XMQRiv58v/gCe74gAUnPPZ8P9zcXPIIqylUnUX2OPSSwQr8WH 8EUcmIeKqT+xvTO+7iH9MyEGsg== X-Google-Smtp-Source: ADFU+vs42YnfFoDBWropckxwcqamVQFJr8JXz3WKntS902p8kIlNkYJMI4GVpocQ6GUGg2mBvy2tIA== X-Received: by 2002:a17:90a:eb18:: with SMTP id j24mr1052188pjz.85.1583296257790; Tue, 03 Mar 2020 20:30:57 -0800 (PST) Received: from santosiv.in.ibm.com ([2401:4900:16ee:7b5f:eac:4364:ff14:3aaa]) by smtp.gmail.com with ESMTPSA id y193sm10775723pfg.162.2020.03.03.20.30.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Mar 2020 20:30:57 -0800 (PST) From: Santosh Sivaraj To: , linuxppc-dev Subject: [PATCH v2 4/6] powerpc/mmu_gather: enable RCU_TABLE_FREE even for !SMP case Date: Wed, 4 Mar 2020 10:00:26 +0530 Message-Id: <20200304043028.280136-5-santosh@fossix.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200304043028.280136-1-santosh@fossix.org> References: <20200304043028.280136-1-santosh@fossix.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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: Sasha Levin , "Aneesh Kumar K.V" , Greg KH Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: "Aneesh Kumar K.V" commit 12e4d53f3f04e81f9e83d6fc10edc7314ab9f6b9 upstream. Patch series "Fixup page directory freeing", v4. This is a repost of patch series from Peter with the arch specific changes except ppc64 dropped. ppc64 changes are added here because we are redoing the patch series on top of ppc64 changes. This makes it easy to backport these changes. Only the first 2 patches need to be backported to stable. The thing is, on anything SMP, freeing page directories should observe the exact same order as normal page freeing: 1) unhook page/directory 2) TLB invalidate 3) free page/directory Without this, any concurrent page-table walk could end up with a Use-after-Free. This is esp. trivial for anything that has software page-table walkers (HAVE_FAST_GUP / software TLB fill) or the hardware caches partial page-walks (ie. caches page directories). Even on UP this might give issues since mmu_gather is preemptible these days. An interrupt or preempted task accessing user pages might stumble into the free page if the hardware caches page directories. This patch series fixes ppc64 and add generic MMU_GATHER changes to support the conversion of other architectures. I haven't added patches w.r.t other architecture because they are yet to be acked. This patch (of 9): A followup patch is going to make sure we correctly invalidate page walk cache before we free page table pages. In order to keep things simple enable RCU_TABLE_FREE even for !SMP so that we don't have to fixup the !SMP case differently in the followup patch !SMP case is right now broken for radix translation w.r.t page walk cache flush. We can get interrupted in between page table free and that would imply we have page walk cache entries pointing to tables which got freed already. Michael said "both our platforms that run on Power9 force SMP on in Kconfig, so the !SMP case is unlikely to be a problem for anyone in practice, unless they've hacked their kernel to build it !SMP." Link: http://lkml.kernel.org/r/20200116064531.483522-2-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V Cc: # 4.19 Signed-off-by: Santosh Sivaraj [santosh: backported for 4.19 stable] --- arch/powerpc/Kconfig | 2 +- arch/powerpc/include/asm/book3s/32/pgalloc.h | 8 -------- arch/powerpc/include/asm/book3s/64/pgalloc.h | 2 -- arch/powerpc/mm/pgtable-book3s64.c | 7 ------- 4 files changed, 1 insertion(+), 18 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index e09cfb109b8c..1a00ce4b0040 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -215,7 +215,7 @@ config PPC select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI && !HAVE_HARDLOCKUP_DETECTOR_ARCH select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP - select HAVE_RCU_TABLE_FREE if SMP + select HAVE_RCU_TABLE_FREE select HAVE_RCU_TABLE_NO_INVALIDATE if HAVE_RCU_TABLE_FREE select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RELIABLE_STACKTRACE if PPC64 && CPU_LITTLE_ENDIAN diff --git a/arch/powerpc/include/asm/book3s/32/pgalloc.h b/arch/powerpc/include/asm/book3s/32/pgalloc.h index 82e44b1a00ae..79ba3fbb512e 100644 --- a/arch/powerpc/include/asm/book3s/32/pgalloc.h +++ b/arch/powerpc/include/asm/book3s/32/pgalloc.h @@ -110,7 +110,6 @@ static inline void pgtable_free(void *table, unsigned index_size) #define check_pgt_cache() do { } while (0) #define get_hugepd_cache_index(x) (x) -#ifdef CONFIG_SMP static inline void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift) { @@ -127,13 +126,6 @@ static inline void __tlb_remove_table(void *_table) pgtable_free(table, shift); } -#else -static inline void pgtable_free_tlb(struct mmu_gather *tlb, - void *table, int shift) -{ - pgtable_free(table, shift); -} -#endif static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table, unsigned long address) diff --git a/arch/powerpc/include/asm/book3s/64/pgalloc.h b/arch/powerpc/include/asm/book3s/64/pgalloc.h index f9019b579903..1013c0214213 100644 --- a/arch/powerpc/include/asm/book3s/64/pgalloc.h +++ b/arch/powerpc/include/asm/book3s/64/pgalloc.h @@ -47,9 +47,7 @@ extern pmd_t *pmd_fragment_alloc(struct mm_struct *, unsigned long); extern void pte_fragment_free(unsigned long *, int); extern void pmd_fragment_free(unsigned long *); extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift); -#ifdef CONFIG_SMP extern void __tlb_remove_table(void *_table); -#endif static inline pgd_t *radix__pgd_alloc(struct mm_struct *mm) { diff --git a/arch/powerpc/mm/pgtable-book3s64.c b/arch/powerpc/mm/pgtable-book3s64.c index 297db665d953..5b4e9fd8990c 100644 --- a/arch/powerpc/mm/pgtable-book3s64.c +++ b/arch/powerpc/mm/pgtable-book3s64.c @@ -432,7 +432,6 @@ static inline void pgtable_free(void *table, int index) } } -#ifdef CONFIG_SMP void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int index) { unsigned long pgf = (unsigned long)table; @@ -449,12 +448,6 @@ void __tlb_remove_table(void *_table) return pgtable_free(table, index); } -#else -void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int index) -{ - return pgtable_free(table, index); -} -#endif #ifdef CONFIG_PROC_FS atomic_long_t direct_pages_count[MMU_PAGE_COUNT]; -- 2.24.1