All of lore.kernel.org
 help / color / mirror / Atom feed
From: Usama Arif <usamaarif642@gmail.com>
To: Dave Young <dyoung@redhat.com>
Cc: linux-efi@vger.kernel.org, devel@edk2.groups.io,
	kexec@lists.infradead.org, ardb@kernel.org, hannes@cmpxchg.org,
	x86@kernel.org, linux-kernel@vger.kernel.org, leitao@debian.org,
	gourry@gourry.net, kernel-team@meta.com
Subject: Re: [RFC 2/2] efi/memattr: add efi_mem_attr_table as a reserved region in 820_table_firmware
Date: Fri, 10 Jan 2025 11:12:41 +0000	[thread overview]
Message-ID: <4ed67e5b-c2ea-4dc3-b4c5-f8f112b0cd40@gmail.com> (raw)
In-Reply-To: <CALu+AoTgjdq+kUbv-5CGQr=UTLd2+zDLbHt=kXaoMYYptBYnAA@mail.gmail.com>



On 10/01/2025 02:50, Dave Young wrote:
> Hi Usama,
> 
> On Thu, 9 Jan 2025 at 06:00, Usama Arif <usamaarif642@gmail.com> wrote:
>>
>> When this area is not reserved, it comes up as usable in
>> /sys/firmware/memmap. This means that kexec, which uses that memmap
>> to find usable memory regions, can select the region where
>> efi_mem_attr_table is and overwrite it and relocate_kernel.
> 
> Is the attr table BOOT SERVICE DATA?  If so, does efi_mem_reserve()
> work for you?
> Just refer to esrt.c.
> 

Hi Dave,

Its a bit difficult to reproduce the problem and therefore test the fix, but
we are seeing it a lot in production. Ard proposed the same thing in 
https://lore.kernel.org/all/6b4780a5-ada0-405e-9f0a-4d2186177f29@gmail.com/
but as I mentioned there, I dont think that efi_mem_reserve would help,
as efi_mem_reserve changes e820_table, while kexec looks at
/sys/firmware/memmap which uses e820_table_firmware.

Thanks,
Usama

> Thanks
> Dave
> 



  reply	other threads:[~2025-01-10 11:12 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-01-08 21:53 [RFC 0/2] efi/memattr: Fix memory corruption and warning issues Usama Arif
2025-01-08 21:53 ` [RFC 1/2] efi/memattr: Use desc_size instead of total size to check for corruption Usama Arif
2025-01-09 15:45   ` Ard Biesheuvel
2025-01-09 16:36     ` Usama Arif
2025-01-10  7:21       ` Ard Biesheuvel
2025-01-10 10:53         ` Usama Arif
2025-01-10 17:25           ` Ard Biesheuvel
2025-01-13  2:33           ` Dave Young
2025-01-13 11:27             ` Usama Arif
2025-01-13 12:00               ` Usama Arif
2025-01-20 10:27                 ` Usama Arif
2025-01-20 10:32                   ` Ard Biesheuvel
2025-01-20 10:50                     ` Usama Arif
2025-01-20 11:29                       ` Ard Biesheuvel
2025-01-20 11:48                         ` Usama Arif
2025-01-22  5:36                           ` Dave Young
2025-01-22 11:50                             ` Usama Arif
2025-01-08 21:53 ` [RFC 2/2] efi/memattr: add efi_mem_attr_table as a reserved region in 820_table_firmware Usama Arif
2025-01-09 16:15   ` Ard Biesheuvel
2025-01-09 16:32     ` Usama Arif
2025-01-09 16:47       ` Gregory Price
2025-01-10  7:32       ` Ard Biesheuvel
2025-01-10 11:36         ` Breno Leitao
2025-01-10 17:33           ` Ard Biesheuvel
2025-01-10 14:31         ` Usama Arif
2025-01-10 15:50           ` Usama Arif
2025-01-10  2:50   ` Dave Young
2025-01-10 11:12     ` Usama Arif [this message]
2025-01-10 11:18       ` Dave Young
2025-01-10 11:20         ` Dave Young
2025-01-10 11:42           ` Usama Arif
2025-01-10  6:56   ` kernel test robot

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4ed67e5b-c2ea-4dc3-b4c5-f8f112b0cd40@gmail.com \
    --to=usamaarif642@gmail.com \
    --cc=ardb@kernel.org \
    --cc=devel@edk2.groups.io \
    --cc=dyoung@redhat.com \
    --cc=gourry@gourry.net \
    --cc=hannes@cmpxchg.org \
    --cc=kernel-team@meta.com \
    --cc=kexec@lists.infradead.org \
    --cc=leitao@debian.org \
    --cc=linux-efi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.