Subject: Re: linux-next: build failure after merge of the perf tree

From: Stephen Rothwell <[email-masked]>
Date: Wed, 29 Mar 2023 10:06:12 +1100

Hi Arnaldo,

On Tue, 28 Mar 2023 16:47:23 -0300 Arnaldo Carvalho de Melo <[email-masked]> wrote:
> 
> The config files you used don't match the running kernels

This is just the way Debian names its kernel packages.

> > $ uname -a
> > Linux zz1 6.0.0-5-powerpc64le #1 SMP Debian 6.0.10-2 (2022-12-01) ppc64le GNU/Linux
              ^^^^^^^^^^^^^^^^^^^
> > $ ls -l /sys/kernel/bpf/
> > ls: cannot access '/sys/kernel/bpf/': No such file or directory
> > $ grep CONFIG_DEBUG_INFO_BTF /boot/config-6.0.0-5-powerpc64le
                                              ^^^^^^^^^^^^^^^^^^^

And so on.  It just happens that this kernel is based on v6.0.10.

$ uname -r
6.0.0-5-powerpc64le

So they are the correct config files.

Also, the mail I replied to talked about checking /sys/kernel/bpf/ (not
btf) :-(

still on my build machine (of course):

$ ls -l /sys/kernel/btf/
ls: cannot access '/sys/kernel/btf/': No such file or directory

So it seems that Debian do not build their powerpcle kernels with
CONFIG_DEBUG_INFO_BTF. I don't know why not since all the dependencies
seem to be OK.

[On my arm64 machine:

$ ls -l /sys/kernel/btf/vmlinux
-r--r--r-- 1 root root 5209570 Mar 29 09:52 /sys/kernel/btf/vmlinux

and on my amd64 machine:

$ ls -l /sys/kernel/btf/vmlinux
-r--r--r-- 1 root root 8536946 Mar 29 10:04 /sys/kernel/btf/vmlinux
]
-- 
Cheers,
Stephen Rothwell