From 1c154b4c15cfc63e06ad1c48a801064677e874e2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fabiano=20Fid=C3=AAncio?= Date: Fri, 16 Jan 2026 12:03:34 +0100 Subject: [PATCH] kernel: Add DAX fix for arm64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch has been provided upstream by Seunguk Shin and is already approved. We'll drop it once it becomes available in the LTS tree. Reference: https://lore.kernel.org/all/18af3213-6c46-4611-ba75-da5be5a1c9b0@arm.coum Signed-off-by: Fabiano Fidêncio --- tools/packaging/kernel/kata_config_version | 2 +- ...empty-entry-before-converting-xarray.patch | 170 ++++++++++++++++++ .../kernel/patches/6.18.x/no_patches.txt | 0 3 files changed, 171 insertions(+), 1 deletion(-) create mode 100644 tools/packaging/kernel/patches/6.18.x/0001-fs-dax-check-zero-or-empty-entry-before-converting-xarray.patch delete mode 100644 tools/packaging/kernel/patches/6.18.x/no_patches.txt diff --git a/tools/packaging/kernel/kata_config_version b/tools/packaging/kernel/kata_config_version index f07e2860a4..1057e9a273 100644 --- a/tools/packaging/kernel/kata_config_version +++ b/tools/packaging/kernel/kata_config_version @@ -1 +1 @@ -175 +176 diff --git a/tools/packaging/kernel/patches/6.18.x/0001-fs-dax-check-zero-or-empty-entry-before-converting-xarray.patch b/tools/packaging/kernel/patches/6.18.x/0001-fs-dax-check-zero-or-empty-entry-before-converting-xarray.patch new file mode 100644 index 0000000000..c61319d6a8 --- /dev/null +++ b/tools/packaging/kernel/patches/6.18.x/0001-fs-dax-check-zero-or-empty-entry-before-converting-xarray.patch @@ -0,0 +1,170 @@ +From mboxrd@z Thu Jan 1 00:00:00 1970 +Received: from foss.arm.com (foss.arm.com [217.140.110.172]) + by smtp.subspace.kernel.org (Postfix) with ESMTP id BCE6D2FFDD5 + for ; Wed, 14 Jan 2026 17:49:59 +0000 (UTC) +Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 +ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; + t=1768413001; cv=none; b=mYidLRrJZn5ooS7h+lyKLsbA8/GKL/ZqDOCHo66hKab86eV5cgpwbWPeudpYGPiMp/QhczPxwDzq1J9qP57FU8xy5AmIFwF6cAn6FPN0BzBWxBQUeT/pxDwfOkvh33RigAd/HACiTa+9waLWNn94H1tPpUOn1SUKYcC2anb/EMA= +ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; + s=arc-20240116; t=1768413001; c=relaxed/simple; + bh=/AHMpb4+3MfzIhYBPESp8KGt8HTeUy14LUGKGDaY7Jc=; + h=Message-ID:Date:MIME-Version:To:Cc:From:Subject:Content-Type; b=nYCvtwNmfNPRI2kMt6FzMOpG8Xv2GrytpiVJh3K4jRBpJFo3NO0icdYoGz0yjvq1G4vQvh/VrhrLhOVAEHdNkuGQz1yL6qHm/9KniwafY98ihbvaadCAZtdiNtjhZ646/irNi48nnwxquGqUkiPk2n9PqYSVLR9VYf60nr/nAOA= +ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 +Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com +Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com +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 4F3F21515; + Wed, 14 Jan 2026 09:49:52 -0800 (PST) +Received: from [10.1.37.132] (unknown [10.1.37.132]) + by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0CA253F59E; + Wed, 14 Jan 2026 09:49:57 -0800 (PST) +Message-ID: <18af3213-6c46-4611-ba75-da5be5a1c9b0@arm.com> +Date: Wed, 14 Jan 2026 17:49:30 +0000 +Precedence: bulk +X-Mailing-List: nvdimm@lists.linux.dev +List-Id: +List-Subscribe: +List-Unsubscribe: +MIME-Version: 1.0 +User-Agent: Mozilla Thunderbird +Content-Language: en-US +To: linux-kernel@vger.kernel.org +Cc: linux-fsdevel@vger.kernel.org, nvdimm@lists.linux.dev, + dan.j.williams@intel.com, willy@infradead.org, jack@suse.cz, + Nick.Connolly@arm.com, ffidencio@nvidia.com +From: Seunguk Shin +Subject: [PATCH] fs/dax: check zero or empty entry before converting xarray +Content-Type: text/plain; charset=UTF-8; format=flowed +Content-Transfer-Encoding: 8bit + +Trying to convert zero or empty xarray entry causes kernel panic. + +[ 0.737679] EXT4-fs (pmem0p1): mounted filesystem +79676804-7c8b-491a-b2a6-9bae3c72af70 ro with ordered data mode. Quota +mode: disabled. +[ 0.737891] VFS: Mounted root (ext4 filesystem) readonly on device 259:1. +[ 0.739119] devtmpfs: mounted +[ 0.739476] Freeing unused kernel memory: 1920K +[ 0.740156] Run /sbin/init as init process +[ 0.740229] with arguments: +[ 0.740286] /sbin/init +[ 0.740321] with environment: +[ 0.740369] HOME=/ +[ 0.740400] TERM=linux +[ 0.743162] Unable to handle kernel paging request at virtual address +fffffdffbf000008 +[ 0.743285] Mem abort info: +[ 0.743316] ESR = 0x0000000096000006 +[ 0.743371] EC = 0x25: DABT (current EL), IL = 32 bits +[ 0.743444] SET = 0, FnV = 0 +[ 0.743489] EA = 0, S1PTW = 0 +[ 0.743545] FSC = 0x06: level 2 translation fault +[ 0.743610] Data abort info: +[ 0.743656] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 +[ 0.743720] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 +[ 0.743785] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 +[ 0.743848] swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000b9d17000 +[ 0.743931] [fffffdffbf000008] pgd=10000000bfa3d403, +p4d=10000000bfa3d403, pud=1000000040bfe403, pmd=0000000000000000 +[ 0.744070] Internal error: Oops: 0000000096000006 [#1] SMP +[ 0.748888] CPU: 0 UID: 0 PID: 1 Comm: init Not tainted 6.18.4 #1 NONE +[ 0.749421] pstate: 004000c5 (nzcv daIF +PAN -UAO -TCO -DIT -SSBS +BTYPE=--) +[ 0.749969] pc : dax_disassociate_entry.constprop.0+0x20/0x50 +[ 0.750444] lr : dax_insert_entry+0xcc/0x408 +[ 0.750802] sp : ffff80008000b9e0 +[ 0.751083] x29: ffff80008000b9e0 x28: 0000000000000000 x27: +0000000000000000 +[ 0.751682] x26: 0000000001963d01 x25: ffff0000004f7d90 x24: +0000000000000000 +[ 0.752264] x23: 0000000000000000 x22: ffff80008000bcc8 x21: +0000000000000011 +[ 0.752836] x20: ffff80008000ba90 x19: 0000000001963d01 x18: +0000000000000000 +[ 0.753407] x17: 0000000000000000 x16: 0000000000000000 x15: +0000000000000000 +[ 0.753970] x14: ffffbf3154b9ae70 x13: 0000000000000000 x12: +ffffbf3154b9ae70 +[ 0.754548] x11: ffffffffffffffff x10: 0000000000000000 x9 : +0000000000000000 +[ 0.755122] x8 : 000000000000000d x7 : 000000000000001f x6 : +0000000000000000 +[ 0.755707] x5 : 0000000000000000 x4 : 0000000000000000 x3 : +fffffdffc0000000 +[ 0.756287] x2 : 0000000000000008 x1 : 0000000040000000 x0 : +fffffdffbf000000 +[ 0.756871] Call trace: +[ 0.757107] dax_disassociate_entry.constprop.0+0x20/0x50 (P) +[ 0.757592] dax_iomap_pte_fault+0x4fc/0x808 +[ 0.757951] dax_iomap_fault+0x28/0x30 +[ 0.758258] ext4_dax_huge_fault+0x80/0x2dc +[ 0.758594] ext4_dax_fault+0x10/0x3c +[ 0.758892] __do_fault+0x38/0x12c +[ 0.759175] __handle_mm_fault+0x530/0xcf0 +[ 0.759518] handle_mm_fault+0xe4/0x230 +[ 0.759833] do_page_fault+0x17c/0x4dc +[ 0.760144] do_translation_fault+0x30/0x38 +[ 0.760483] do_mem_abort+0x40/0x8c +[ 0.760771] el0_ia+0x4c/0x170 +[ 0.761032] el0t_64_sync_handler+0xd8/0xdc +[ 0.761371] el0t_64_sync+0x168/0x16c +[ 0.761677] Code: f9453021 f2dfbfe3 cb813080 8b001860 (f9400401) +[ 0.762168] ---[ end trace 0000000000000000 ]--- +[ 0.762550] note: init[1] exited with irqs disabled +[ 0.762631] Kernel panic - not syncing: Attempted to kill init! +exitcode=0x0000000b + +This patch just reorders checking and converting. + +Signed-off-by: Seunguk Shin +--- + fs/dax.c | 9 ++++++--- + 1 file changed, 6 insertions(+), 3 deletions(-) + +diff --git a/fs/dax.c b/fs/dax.c +index 516f995a9..69ac2562c 100644 +--- a/fs/dax.c ++++ b/fs/dax.c +@@ -443,11 +443,12 @@ static void dax_associate_entry(void *entry, struct address_space *mapping, + unsigned long address, bool shared) + { + unsigned long size = dax_entry_size(entry), index; +- struct folio *folio = dax_to_folio(entry); ++ struct folio *folio; + + if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) + return; + ++ folio = dax_to_folio(entry); + index = linear_page_index(vma, address & ~(size - 1)); + if (shared && (folio->mapping || dax_folio_is_shared(folio))) { + if (folio->mapping) +@@ -468,21 +469,23 @@ static void dax_associate_entry(void *entry, struct address_space *mapping, + static void dax_disassociate_entry(void *entry, struct address_space *mapping, + bool trunc) + { +- struct folio *folio = dax_to_folio(entry); ++ struct folio *folio; + + if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) + return; + ++ folio = dax_to_folio(entry); + dax_folio_put(folio); + } + + static struct page *dax_busy_page(void *entry) + { +- struct folio *folio = dax_to_folio(entry); ++ struct folio *folio; + + if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) + return NULL; + ++ folio = dax_to_folio(entry); + if (folio_ref_count(folio) - folio_mapcount(folio)) + return &folio->page; + else +-- +2.43.0 + diff --git a/tools/packaging/kernel/patches/6.18.x/no_patches.txt b/tools/packaging/kernel/patches/6.18.x/no_patches.txt deleted file mode 100644 index e69de29bb2..0000000000