From patchwork Mon Jul 22 15:42:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Price X-Patchwork-Id: 11052857 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2FE2913AC for ; Mon, 22 Jul 2019 15:48:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1C95328414 for ; Mon, 22 Jul 2019 15:48:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1023B28438; Mon, 22 Jul 2019 15:48:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id B49AD28433 for ; Mon, 22 Jul 2019 15:48:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=3dhep0PYQwQ8Cm4dvDqvS3J4gXolUttRNkJ6LZYeims=; b=th89YFNLGfMa3p JHthDSVrjLezK7BA0sWQJGSmwzSyyqavFfePNpk3LBTvB5It7qUYn1TN3fWS7aiCpXLEMG8Et1pPD FWeNBzAWQv6TWseswC92auvx87V6jp0WBQ5H9LmxsBoEtd2Aeij0+LMXRVg8ujsZDgcHZRdCnRH8c eZCPGHBUbPvCq741FfIRxdukLZDK5CgMkBMV7hFM1Eg366huc+4rbOfTaA2LzJkHbdC9rUQaiqj0A KwaCgAVWWOQIltHE/e31Dl7JuaWVYKA1CDJUCT754IihdUszU5fJjGLArHmOrXgW/f03g3lHxVNnD PmJxA5UjIlKszMexNL5w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hpaY7-0006pS-HI; Mon, 22 Jul 2019 15:48:27 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hpaSp-000239-Qi for linux-arm-kernel@lists.infradead.org; Mon, 22 Jul 2019 15:43:01 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 30DF515A2; Mon, 22 Jul 2019 08:42:59 -0700 (PDT) Received: from e112269-lin.arm.com (e112269-lin.cambridge.arm.com [10.1.196.133]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9B72F3F694; Mon, 22 Jul 2019 08:42:56 -0700 (PDT) From: Steven Price To: linux-mm@kvack.org Subject: [PATCH v9 12/21] mm: pagewalk: Allow walking without vma Date: Mon, 22 Jul 2019 16:42:01 +0100 Message-Id: <20190722154210.42799-13-steven.price@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190722154210.42799-1-steven.price@arm.com> References: <20190722154210.42799-1-steven.price@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190722_084300_234096_0457F3BD X-CRM114-Status: GOOD ( 13.68 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , x86@kernel.org, Arnd Bergmann , Ard Biesheuvel , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-kernel@vger.kernel.org, Steven Price , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Ingo Molnar , Borislav Petkov , Andy Lutomirski , "H. Peter Anvin" , James Morse , Thomas Gleixner , Will Deacon , Andrew Morton , linux-arm-kernel@lists.infradead.org, "Liang, Kan" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Since 48684a65b4e3: "mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)", page_table_walk() will report any kernel area as a hole, because it lacks a vma. This means each arch has re-implemented page table walking when needed, for example in the per-arch ptdump walker. Remove the requirement to have a vma except when trying to split huge pages. Signed-off-by: Steven Price --- mm/pagewalk.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 98373a9f88b8..1cbef99e9258 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -36,7 +36,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, do { again: next = pmd_addr_end(addr, end); - if (pmd_none(*pmd) || !walk->vma) { + if (pmd_none(*pmd)) { if (walk->pte_hole) err = walk->pte_hole(addr, next, walk); if (err) @@ -59,9 +59,14 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, if (!walk->pte_entry) continue; - split_huge_pmd(walk->vma, pmd, addr); - if (pmd_trans_unstable(pmd)) - goto again; + if (walk->vma) { + split_huge_pmd(walk->vma, pmd, addr); + if (pmd_trans_unstable(pmd)) + goto again; + } else if (pmd_leaf(*pmd)) { + continue; + } + err = walk_pte_range(pmd, addr, next, walk); if (err) break; @@ -81,7 +86,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, do { again: next = pud_addr_end(addr, end); - if (pud_none(*pud) || !walk->vma) { + if (pud_none(*pud)) { if (walk->pte_hole) err = walk->pte_hole(addr, next, walk); if (err) @@ -95,9 +100,13 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, break; } - split_huge_pud(walk->vma, pud, addr); - if (pud_none(*pud)) - goto again; + if (walk->vma) { + split_huge_pud(walk->vma, pud, addr); + if (pud_none(*pud)) + goto again; + } else if (pud_leaf(*pud)) { + continue; + } if (walk->pmd_entry || walk->pte_entry) err = walk_pmd_range(pud, addr, next, walk);