From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 339636A33A for ; Mon, 15 Jul 2024 19:21:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721071311; cv=none; b=fXT4jCTBf4PYtbcPstxHOl0jD7JbROxvwH0d15qMAehU4RaBsPkKr9tpNoJ3jvgHN4dhIo6I3DVg+EVHXi9yzaerru4j27qOrpMwUjIy3tp0+CfnqjkkVK6zC3GPOwZiRWNSuXJNsZ/VjzIq4Xd5qnUR+cXMUdCXNrYZaM1Ig8k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721071311; c=relaxed/simple; bh=7htQciZZmrc97uiuvXFe4uJx+yU6LglrVPysXAXnVI0=; h=From:To:Cc:Subject:Date:Message-ID:Content-Type:MIME-Version; b=cMqM+ky9mjt4AgFl19l9heO3tagRRLZ816yGJM/r766A2PneFSSuW60EZfdEyEIRtHQrbhmAaqBYTOLYO9SYvYxYl3NSFJif4CUtZYWgR3QNoh40qqLcd/UkdxZ0D+YFvfDIYiZA+SaY1UyMY3PokFPEvLnJQD7LAajAZB0QJn0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=YPKNGBK/; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YPKNGBK/" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1721071309; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=fcwbFvUlydJ89LCIJbZYnbeNwq+Aa7yYvNbAx9RPsSI=; b=YPKNGBK/r2lUQD2Dm4bYOahcgNehBdbNr8G/IyWi9FEWdJhRrE4PoKawXKWDYiy2LK080Z My808CXEfhGrqrodB1SlOvRFIhm7U92fOcaWb4HdLrFXuqDJQkEjIDU+2Xp1wGUOJA5beh JQ0ftWTLxEcfzoNm98tpO0z1eESExp8= Received: from mail-qv1-f71.google.com (mail-qv1-f71.google.com [209.85.219.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-88-6LTaJjkXPFqw-TwG5cyrPA-1; Mon, 15 Jul 2024 15:21:48 -0400 X-MC-Unique: 6LTaJjkXPFqw-TwG5cyrPA-1 Received: by mail-qv1-f71.google.com with SMTP id 6a1803df08f44-6b7740643fbso2326556d6.1 for ; Mon, 15 Jul 2024 12:21:46 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721071306; x=1721676106; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=fcwbFvUlydJ89LCIJbZYnbeNwq+Aa7yYvNbAx9RPsSI=; b=harWYBNYuvx85ISPLOUmiX9EZeC21aOiDURnOxR0EqbSwfwekwA3NmnMYnLJZOXgfS RuZB5U6pEn1qkt1gyhN2js9ELEM2RaJXICCpez50fsHIZg6GZB3Vgk9Y9LUF8LSmwQcc h4bYA10DFynSDk0Mif5Rg2sc7LdDupaggCJZXorgBPbYrDUKkY20niEb1RgpZu0V/tPi SJTIdfEYC42DHJkJL6+rkYdr6zAFR80Pnrxfzfhm8AfzEJ6vI/liEGys0DwTG0kZNIk2 zwF96fGaVnrZgnEdILmISVzxx710aQCZy2YjhIfPgZP5n1KczYjAToBe6ZlqhQVMHLyh 5rAw== X-Forwarded-Encrypted: i=1; AJvYcCVQZUWVmZA3pEFzrzwCu8aKy4+XQGrekqgy0LeTH1WoLHkNPXHp+lVzhXMo/D53m3bXQhp3U2Y7HCRFZoc=@vger.kernel.org X-Gm-Message-State: AOJu0YxEKtbfGN6LE4cDULxjeFWauoGLtYaGF6p94K+if+UP3/c412Ap SIrfj6H4iQfPVchD2PJxf6fNyn2e2kgH8e0pChrtU0J6DNKku8+qYLorD3/UQx2Wn0ANW8VrOqz XewS75n/iHHnaw2X8Ye+nTPTNSkhgYu/ymzo+O8gnWe8tZOWjR4jFE8fQP53W/w== X-Received: by 2002:a05:6214:3d87:b0:6b2:b5b5:124e with SMTP id 6a1803df08f44-6b77dd634e7mr5106726d6.0.1721071306259; Mon, 15 Jul 2024 12:21:46 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFu7hXxUrNpLJfANABTNicknn5i9R99x8eQnIUTwDJYLFg/NIIa0kT9/i+hFib8ttrRFUJmhA== X-Received: by 2002:a05:6214:3d87:b0:6b2:b5b5:124e with SMTP id 6a1803df08f44-6b77dd634e7mr5106546d6.0.1721071305812; Mon, 15 Jul 2024 12:21:45 -0700 (PDT) Received: from x1n.redhat.com (pool-99-254-121-117.cpe.net.cable.rogers.com. [99.254.121.117]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6b761978d30sm24039356d6.31.2024.07.15.12.21.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Jul 2024 12:21:45 -0700 (PDT) From: Peter Xu To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Dave Jiang , Rik van Riel , Dave Hansen , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, Matthew Wilcox , Rick P Edgecombe , peterx@redhat.com, Oscar Salvador , Mel Gorman , Andrew Morton , Borislav Petkov , Christophe Leroy , Huang Ying , "Kirill A . Shutemov" , "Aneesh Kumar K . V" , Dan Williams , Thomas Gleixner , Hugh Dickins , x86@kernel.org, Nicholas Piggin , Vlastimil Babka , Ingo Molnar Subject: [PATCH v3 0/8] mm/mprotect: Fix dax puds Date: Mon, 15 Jul 2024 15:21:34 -0400 Message-ID: <20240715192142.3241557-1-peterx@redhat.com> X-Mailer: git-send-email 2.45.0 Content-Type: text/plain; charset="utf-8" Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit [Based on mm-unstable, commit 31334cf98dbd, July 2nd] v3: - Fix a build issue on i386 PAE config - Moved one line from patch 8 to patch 3 v1: https://lore.kernel.org/r/20240621142504.1940209-1-peterx@redhat.com v2: https://lore.kernel.org/r/20240703212918.2417843-1-peterx@redhat.com Dax supports pud pages for a while, but mprotect on puds was missing since the start. This series tries to fix that by providing pud handling in mprotect(). The goal is to add more types of pud mappings like hugetlb or pfnmaps. This series paves way for it by fixing known pud entries. Considering nobody reported this until when I looked at those other types of pud mappings, I am thinking maybe it doesn't need to be a fix for stable and this may not need to be backported. I would guess whoever cares about mprotect() won't care 1G dax puds yet, vice versa. I hope fixing that in new kernels would be fine, but I'm open to suggestions. There're a few small things changed to teach mprotect work on PUDs. E.g. it will need to start with dropping NUMA_HUGE_PTE_UPDATES which may stop making sense when there can be more than one type of huge pte. OTOH, we'll also need to push the mmu notifiers from pmd to pud layers, which might need some attention but so far I think it's safe. For such details, please refer to each patch's commit message. The mprotect() pud process should be straightforward, as I kept it as simple as possible. There's no NUMA handled as dax simply doesn't support that. There's also no userfault involvements as file memory (even if work with userfault-wp async mode) will need to split a pud, so pud entry doesn't need to yet know userfault's existance (but hugetlb entries will; that's also for later). Tests ===== What I did test: - cross-build tests that I normally cover [1] - smoke tested on x86_64 the simplest program [2] on dev_dax 1G PUD mprotect() using QEMU's nvdimm emulations [3] and ndctl to create namespaces with proper alignments, which used to throw "bad pud" but now it'll run through all fine. I checked sigbus happens if with illegal access on protected puds. - vmtests. What I didn't test: - fsdax: I wanted to also give it a shot, but only until then I noticed it doesn't seem to be supported (according to dax_iomap_fault(), which will always fallback on PUD_ORDER). I did remember it was supported before, I could miss something important there.. please shoot if so. - userfault wp-async: I also wanted to test userfault-wp async be able to split huge puds (here it's simply a clear_pud.. though), but it won't work for devdax anyway due to not allowed to do smaller than 1G faults in this case. So skip too. - Power, as no hardware on hand. Thanks, [1] https://gitlab.com/peterx/lkb-harness/-/blob/main/config.json [2] https://github.com/xzpeter/clibs/blob/master/misc/dax.c [3] https://github.com/qemu/qemu/blob/master/docs/nvdimm.txt Peter Xu (8): mm/dax: Dump start address in fault handler mm/mprotect: Remove NUMA_HUGE_PTE_UPDATES mm/mprotect: Push mmu notifier to PUDs mm/powerpc: Add missing pud helpers mm/x86: Make pud_leaf() only cares about PSE bit mm/x86: arch_check_zapped_pud() mm/x86: Add missing pud helpers mm/mprotect: fix dax pud handlings arch/powerpc/include/asm/book3s/64/pgtable.h | 3 + arch/powerpc/mm/book3s64/pgtable.c | 20 ++++++ arch/x86/include/asm/pgtable.h | 68 +++++++++++++++--- arch/x86/mm/pgtable.c | 19 +++++ drivers/dax/device.c | 6 +- include/linux/huge_mm.h | 24 +++++++ include/linux/pgtable.h | 7 ++ include/linux/vm_event_item.h | 1 - mm/huge_memory.c | 56 ++++++++++++++- mm/mprotect.c | 74 ++++++++++++-------- mm/vmstat.c | 1 - 11 files changed, 234 insertions(+), 45 deletions(-) -- 2.45.0