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Message-ID: <1a5aed22-63ec-4445-b449-39659f414e79@163.com>
Date: Fri, 1 Mar 2024 10:55:12 +0800
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Subject: Re: [PATCH] PM: hibernate: Fix level3 translation fault in
 swsusp_save()
To: Mike Rapoport <rppt@kernel.org>
Cc: David Hildenbrand <david@redhat.com>, rafael@kernel.org, pavel@ucw.cz,
 len.brown@intel.com, keescook@chromium.org, tony.luck@intel.com,
 gpiccoli@igalia.com, akpm@linux-foundation.org, ardb@kernel.org,
 wangkefeng.wang@huawei.com, catalin.marinas@arm.com, will@kernel.org,
 linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-hardening@vger.kernel.org, Yaxiong Tian <tianyaxiong@kylinos.cn>,
 xiongxin <xiongxin@kylinos.cn>
References: <20240226034225.48689-1-13327272236@163.com>
 <8d70939f-ca14-4167-9647-b8f44ddcbb98@redhat.com>
 <ZdxWcG2XCqBum3_R@kernel.org> <3399d2af-3d42-4ac1-9b74-8475bec25f7f@163.com>
 <ZeBRfxQ8WTEVzpfL@kernel.org>
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From: Yaxiong Tian <13327272236@163.com>
In-Reply-To: <ZeBRfxQ8WTEVzpfL@kernel.org>
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在 2024/2/29 17:42, Mike Rapoport 写道:
> On Tue, Feb 27, 2024 at 03:51:25PM +0800, Yaxiong Tian wrote:
>> 在 2024/2/26 17:14, Mike Rapoport 写道:
>>> On Mon, Feb 26, 2024 at 09:37:06AM +0100, David Hildenbrand wrote:
>>>> On 26.02.24 04:42, Yaxiong Tian wrote:
>>>>> From: Yaxiong Tian <tianyaxiong@kylinos.cn>
>>>>>
>>>>> On ARM64 machines using UEFI, if the linear map is not set (can_set_direct_map()
>>>>> return false), swsusp_save() will fail due to can't finding the map table
>>>>> under the nomap memory.such as:
>>> can_set_direct_map() has nothing to do with presence or absence of the
>>> linear map.
>>>
>>> Do you mean that kernel_page_present() presumes that a page is present when
>>> can_set_direct_map() returns false even for NOMAP ranges?
>> Yes， in swsusp_save()->copy_data_pages()->page_is_saveable(),
>> kernel_page_present() presumes that a page is present when
>> can_set_direct_map()
>> returns false even for NOMAP ranges.So NOMAP pages will saved in after,and
>> then
>> cause level3 translation fault in this pages.
> So this should be the description of the problem in the changelog rather
> than saying "if the linear map is not set (can_set_direct_map() return
> false)"
>
>>>>> QEMU ARM64 using UEFI also has the problem by setting can_set_direct_map()
>>>>> return false.
>>> Huh?
>>> Why would you do that?
>>>
>> I discovered this problem when upgrading from 5.4 to 6.6 using the 5.4
>> configuration.
>> So I using latest linux-next code,find the problem still exist.To rule out
>> the effects
>> of a particular machine，I also use qemu to check it.
> I believe this can be reproduced if you boot with rodata=off and then
> a better description would be something like
>
> 	This issue can be reproduced in QEMU when booting with rodata=off

Thanks, I opt commit messages,and move !pfn_is_map_memory() check from 
page_is_saveable()
to arm64::pfn_is_nosave().  The patch v2 is in:

https://lore.kernel.org/all/20240301021924.33210-1-13327272236@163.com/

I heard that if it is a single PATCH it should be placed under the 
original mailing list,
so please ignore the February 27 patch mailing.

>