Linux sysfs's spectre_v2 output is different in two orin ，Why？ and What consequences will it bring？

Autonomous Machines Jetson & Embedded Systems Jetson AGX Orin
1

In our Jetson orin Evaluation board, the “/sys/devices/system/cpu/vulnerabilities/spectre_v2” output is “Not Affected”。
But，in our Road testing vehicle (domain controller use orin), the “/sys/devices/system/cpu/vulnerabilities/spectre_v2” output is “Mitigation; CSV2, BHB”。
We have reviewed the linux kernel source code，From the source code，the spectre_v2’ s output is based on the cpu and firmware.
Therefore, the spectre_v2’ s different output mean different CPU or firmware.
So, why is there such a difference? What consequences will this change bring?

2

What are those Orin modules? Any P/N?
Are they on the same JetPack SW version? The latest release is Jetpack 5.1.2. If you use previous version, please upgrade and check again.

4

I can remote lo

I can remotely log in Orin Evaluation board by ssh， But i don’t know the Orin modules, P/N, and JetPack SW version. What commands are available to obtain this information？

5

Hi,
Please run the command in Jetson AGX Orin FAQ

Q: How do I know which Jetson Linux release I am using?
Q: How to know if I use Orin developer kit or Orin 32GB module?

6

Hi , The Jetson Orin Evaluation board’ s output:

  1. cat /sys/firmware/devicetree/base/model
    NVIDIA Orin Jetson-Small Developer Kit
  2. cat /etc/nv_tegra_release

R34 (release), REVISION: 1.1, GCID: 30414990, BOARD: t186ref, EABI: aarch64, DATE: Tue May 17 04:20:55 UTC 2022

  1. cat /etc/nv_boot_control.conf
    TNSPEC 3701-500-0000-H.0-1-1-jetson-agx-orin-devkit-mmcblk0p1
    COMPATIBLE_SPEC 3701----1–jetson-agx-orin-devkit-
    TEGRA_CHIPID 0x23
    TEGRA_OTA_BOOT_DEVICE /dev/mtdblock0
    TEGRA_OTA_GPT_DEVICE /dev/mtdblock0

In Road testing vehicle, the output is :

  1. cat /sys/firmware/devicetree/base/model
    3663-0001
  2. cat /etc/nv_tegra_release
    No such file or directory
  3. cat /etc/nv_boot_control.conf
    No such file or directory

From the the road test vehicle‘s output, it can be seen that should have modified rootfs, and the nv_* file under the /etc/ folder is no longer present.

So, Is there any other way to obtain the necessary information?

7

Hi,
r34.1.1(Jetpack 5.0.1) is not a production release. Please re-flash to Jetpack 5.1.2(r35.4.1) through SDKManager and try again.

8

Hi,
For Road testing vehicle, Is there any other way to obtain the Jetpack release?

9

Hi, in our other Orin evaluation board， the /etc/nv_tegra_release 's output is:
# R35 (release), REVISION: 3.1, GCID: 32827747, BOARD: t186ref, EABI: aarch64, DATE: Sun Mar 19 15:19:21 UTC 2023

And , in this board, the “/sys/devices/system/cpu/vulnerabilities/spectre_v2” output is also “Not Affected”。

10

Hi,
It looks like the vehicle does not use L4T but driver os:
https://developer.nvidia.com/drive/driveos

Please help confirm this. And do you see any issue in the different setup? The two releases are for different use-cases so certain setups can be different. If you see any issues from it, please let us know.

11

yes, the vehicle is based on Driver OS。

12

In the vehicle，Under the Linux RT kernel, read_ Lock/write_ Lock is may be more easily affected by out-of-order pipeline。

13

Hi,
Do you mean this is an issue on Driver OS? Please share detail of the issue you are facing so that we can check with our teams.

14

The issue is that the read/write lock modification in Linux’s RT patch did not take into account pipeline out-of-order.
We fixed it based on this patch from the RT community。
https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/commit/kernel/locking/rwbase_rt.c?h=linux-6.3.y-rt&id=81121524f1c798c9481bd7900450b72ee7ac2eef
In this patch, there is a detailed description of the issue.

Please check with your team whether this difference(spectre_v2) in the Driver OS will make this issue more likely to occur.

15

Are you using Drive Orin platform?
For Drive OS product, we will need you to use your account with corporate or university email address.
And open topic at Latest DRIVE AGX Orin/DRIVE AGX Orin General topics - NVIDIA Developer Forums to fet visibility and support.
Sorry for any inconvenience.
Thanks

16

No, I’m not using Drive Orin platform.
Our customer is using it.

17

Please have your issue posted at DRIVE Orin forum to get the support. Thanks