linux-kernel - Re: [PATCH 2/5] x86/microcode: Simplify init path even more

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Y1KFCwuf4LrSIBFY@a4bf019067fa.jf.intel.com>
Date:   Fri, 21 Oct 2022 04:39:55 -0700
From:   Ashok Raj <ashok.raj@...el.com>
To:     Borislav Petkov <bp@...en8.de>
CC:     Tony Luck <tony.luck@...el.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Arjan van de Ven <arjan.van.de.ven@...el.com>,
        Jacob Jun Pan <jacob.jun.pan@...el.com>,
        X86 ML <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>,
        Ashok Raj <ashok.raj@...el.com>
Subject: Re: [PATCH 2/5] x86/microcode: Simplify init path even more

Hi Boris

On Fri, Oct 21, 2022 at 12:57:32PM +0200, Borislav Petkov wrote:
> On Fri, Oct 21, 2022 at 03:21:03AM -0700, Ashok Raj wrote:
> > After boot expect to see 0x81 as the revision. But its left with what
> > was loaded at initrd image.
> 
> Are you testing with all patches, including yours or just the 5 I sent
> you?

I tested just with only your patches

I use Ubuntu

Did a unmkinitrd and verified that 0x70 is in it. After extract.

araj@...j-ucode:/tmp/temp/early2/kernel/x86/microcode$ od -x GenuineIntel.bin | grep "0070 2b00"
12102000 0001 0000 0070 2b00 2022 0822 06f8 0008
-------------------^^^^ ^^^^

12102060 0000 0000 00e0 0000 0001 0003 0070 2b00

Patches in my work tree.. I use stgit mostly
araj@...j-ucode:~/work/linux.git.trees$ qyet
     1	+ v2-bp1
     2	+ bp2
     3	+ bp3
     4	+ bp4
     5	+ bp5

Now just copy the 0x81 ucode in /lib/firmware/intel-ucode/
araj@...j-ucode:~/work/ucode$ od -x /lib/firmware/intel-ucode/06-8f-05 | head
0000000 0001 0000 0081 2b00 2022 0906 06f8 0008
------------------^^^^ ^^^^

After reboot that file is unchanged.

dmesg shows:
[    0.000000] microcode: early update: 0x2b000041 -> 0x2b000070, date = 2022-08
-22

araj@...j-ucode:~$ cat /proc/cpuinfo | grep microcode | sort -u
microcode	: 0x2b000070

root@...j-ucode:/home/araj# echo 1 > /sys/devices/system/cpu/microcode/reload 
root@...j-ucode:/home/araj# cat /proc/cpuinfo | grep microcode | sort -u
microcode	: 0x2b000081

dmesg:
[  654.103784] microcode: Attempting late microcode loading - it is dangerous and taints the kernel.
[  654.113807] microcode: You should switch to early loading, if possible.
[  654.613154] microcode: update 0x2b000070 -> 0x2b000081, date = 2022-09-06


> 
> > The filesystem still had 0x81, and can successfuly load after boot is
> > completed.
> 
> By doing late load through sysfs or what does "can successfuly load"
> mean exactly?

I meant by echo 1 > reload

Cheers,
Ashok