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=-5.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 03123C04A6B for ; Mon, 6 May 2019 14:53:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C79052054F for ; Mon, 6 May 2019 14:53:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557154411; bh=AlTtKsKgZWXRO+VchEO+ZdakVY1Z7mSRhb03uM8VTsM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rlqf6byCWVZ3JgSsPWzf3KQlY8UAo9K9B0ldEr8XUoR8knt8rNa4XPss7CYlsf0gb ofOljHbmaj7INKOksgmWx/kyST7Th0gtPcdGnCg6uucyp1e+g9JixKNdYYBYHkhA3b ZKVRPp9+3cjtvH+TBm+MdkEoluWRk4orvr6K+FFM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728812AbfEFOre (ORCPT ); Mon, 6 May 2019 10:47:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:46500 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728798AbfEFOrY (ORCPT ); Mon, 6 May 2019 10:47:24 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DA158214AE; Mon, 6 May 2019 14:47:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557154043; bh=AlTtKsKgZWXRO+VchEO+ZdakVY1Z7mSRhb03uM8VTsM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A/F/BCj1dIW3N47tAP1U7ftupgzJqcweIS5+suq/UxWLcqqWkH/+SsZThzRc/ZsWN scYgC98OQ4B5qm91Hk2I45VtiZ0VTOMIZS2fx2g5svYfiAx826jVd6BU6dDN+jUCOB QMzjCJIklP2kWcWrO1avlL4pp8+zKH1oBJ0PCJSk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Rutland , Will Deacon , Catalin Marinas , Andrey Konovalov Subject: [PATCH 4.9 17/62] arm64: proc: Set PTE_NG for table entries to avoid traversing them twice Date: Mon, 6 May 2019 16:32:48 +0200 Message-Id: <20190506143052.549892170@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190506143051.102535767@linuxfoundation.org> References: <20190506143051.102535767@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Will Deacon commit 2ce77f6d8a9ae9ce6d80397d88bdceb84a2004cd upstream. When KASAN is enabled, the swapper page table contains many identical mappings of the zero page, which can lead to a stall during boot whilst the G -> nG code continually walks the same page table entries looking for global mappings. This patch sets the nG bit (bit 11, which is IGNORED) in table entries after processing the subtree so we can easily skip them if we see them a second time. Tested-by: Mark Rutland Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Andrey Konovalov Signed-off-by: Greg Kroah-Hartman --- arch/arm64/mm/proc.S | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -181,7 +181,8 @@ ENDPROC(idmap_cpu_replace_ttbr1) dc cvac, cur_\()\type\()p // Ensure any existing dirty dmb sy // lines are written back before ldr \type, [cur_\()\type\()p] // loading the entry - tbz \type, #0, next_\()\type // Skip invalid entries + tbz \type, #0, skip_\()\type // Skip invalid and + tbnz \type, #11, skip_\()\type // non-global entries .endm .macro __idmap_kpti_put_pgtable_ent_ng, type @@ -241,8 +242,9 @@ ENTRY(idmap_kpti_install_ng_mappings) add end_pgdp, cur_pgdp, #(PTRS_PER_PGD * 8) do_pgd: __idmap_kpti_get_pgtable_ent pgd tbnz pgd, #1, walk_puds - __idmap_kpti_put_pgtable_ent_ng pgd next_pgd: + __idmap_kpti_put_pgtable_ent_ng pgd +skip_pgd: add cur_pgdp, cur_pgdp, #8 cmp cur_pgdp, end_pgdp b.ne do_pgd @@ -270,8 +272,9 @@ walk_puds: add end_pudp, cur_pudp, #(PTRS_PER_PUD * 8) do_pud: __idmap_kpti_get_pgtable_ent pud tbnz pud, #1, walk_pmds - __idmap_kpti_put_pgtable_ent_ng pud next_pud: + __idmap_kpti_put_pgtable_ent_ng pud +skip_pud: add cur_pudp, cur_pudp, 8 cmp cur_pudp, end_pudp b.ne do_pud @@ -290,8 +293,9 @@ walk_pmds: add end_pmdp, cur_pmdp, #(PTRS_PER_PMD * 8) do_pmd: __idmap_kpti_get_pgtable_ent pmd tbnz pmd, #1, walk_ptes - __idmap_kpti_put_pgtable_ent_ng pmd next_pmd: + __idmap_kpti_put_pgtable_ent_ng pmd +skip_pmd: add cur_pmdp, cur_pmdp, #8 cmp cur_pmdp, end_pmdp b.ne do_pmd @@ -309,7 +313,7 @@ walk_ptes: add end_ptep, cur_ptep, #(PTRS_PER_PTE * 8) do_pte: __idmap_kpti_get_pgtable_ent pte __idmap_kpti_put_pgtable_ent_ng pte -next_pte: +skip_pte: add cur_ptep, cur_ptep, #8 cmp cur_ptep, end_ptep b.ne do_pte