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From: Eric Ren <renzhengeek@gmail.com>
To: David Hildenbrand <david@redhat.com>, linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org, vbabka@suse.cz, ziy@nvidia.com
Subject: Re: [PATCH v2] virtio_mem: fix panic on mb_states indexing overflow
Date: Tue, 21 Dec 2021 22:24:44 +0800	[thread overview]
Message-ID: <5adf42d2-649d-adcc-4598-26263ca27a31@gmail.com> (raw)
In-Reply-To: <14ac1cb4-1cf0-03a3-d412-c35fa9eeea59@redhat.com>

Hi David,

在 12/21/21 9:53 PM, David Hildenbrand 写道:
> Hi Eric,
>
>> _vm->sbm.first_mb_id == 0
> ^ that's precisely what I meant.
Ah, finally got it!
>
> How could it *ever* be safe on x86-64 to let a virtio-mem device start
> on physical address 0, eventually overlapping essentially all DMA, the
> BIOS and the PCI hole.
You're right! That clears my doubt why this "issue" can live so long 
there... util I see it.

Yes, my setup is a very hacking enviroment. The device region start addr 
is wrongly
assigned to 0!

So, let's just drop this patch.

Eric
>
> Thus my question: Is this a "fix" for x86-64 or is this a "prepare for"
> for !x86-64 (e.g., arm64).
>
> If it's a fix, we want proper "Fixes:" and "Cc: stable" tags. But I
> assume this is much rather a preparation for another architecture than
> x86-64.
>
> Thanks!
>



      parent reply	other threads:[~2021-12-21 14:24 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-20 13:18 Eric Ren
     [not found] ` <32103255-7eba-08c1-8ab8-0730486332c1@redhat.com>
2021-12-21 12:39   ` Eric Ren
     [not found]     ` <14ac1cb4-1cf0-03a3-d412-c35fa9eeea59@redhat.com>
2021-12-21 14:24       ` Eric Ren [this message]

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