FS#79573 - [linux-lts] Can not disable BPF jit because it is always on
Attached to Project:
Arch Linux
Opened by - (booo) - Tuesday, 05 September 2023, 13:21 GMT
Last edited by Jelle van der Waa (jelly) - Thursday, 14 September 2023, 17:56 GMT
Opened by - (booo) - Tuesday, 05 September 2023, 13:21 GMT
Last edited by Jelle van der Waa (jelly) - Thursday, 14 September 2023, 17:56 GMT
|
Details
Description:
With commit bfa997bf05079b3870b44ed86bd1b59346f0594a we introduce kernel configuration for the BPF subsystem. We add the BPF system to the kernel and enable it by default. Unfortunately we added the always on option as well (CONFIG_BPF_JIT_ALWAYS_ON=y). It seems to me that it is impossible to disable the BPF JIT given this configration: [root@x220 booo]# echo 0 > /proc/sys/net/core/bpf_jit_enable bash: echo: write error: Invalid argument My current kernel configuration is: ➜ ~ zcat /proc/config.gz | grep BPF_JIT CONFIG_HAVE_EBPF_JIT=y CONFIG_ARCH_WANT_DEFAULT_BPF_JIT=y CONFIG_BPF_JIT=y CONFIG_BPF_JIT_ALWAYS_ON=y CONFIG_BPF_JIT_DEFAULT_ON=y I suggest that we disable the CONFIG_BPF_JIT_ALWAYS_ON option and give the user the freedom to disable the BPF JIT. It is important to be able to disable the JIT because it is broken for e.g. some tcpdump filter rules. Example from the OpenWRT project: https://github.com/openwrt/openwrt/issues/7044 |
This task depends upon
Closed by Jelle van der Waa (jelly)
Thursday, 14 September 2023, 17:56 GMT
Reason for closing: Deferred
Additional comments about closing: Old kernel, please retry with the latest
Thursday, 14 September 2023, 17:56 GMT
Reason for closing: Deferred
Additional comments about closing: Old kernel, please retry with the latest
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=290af86629b25ffd1ed6232c4e9107da031705cb
[1] https://src.fedoraproject.org/rpms/kernel/blob/f38/f/kernel-x86_64-fedora.config#_647
[2[ https://salsa.debian.org/kernel-team/linux/-/blob/bookworm/debian/config/config#L6487