Re: [PATCH dwarves v2] dwarf_loader: Fix skipped encoding of function BTF on 32-bit systems

["Alexis Lothoré" <alexis.lothore@bootlin.com>]

On Fri May 9, 2025 at 7:21 AM CEST, Tony Ambardar wrote:
> Hi Alexis,
>
> On Thu, May 08, 2025 at 11:38:06AM +0200, Alexis Lothoré wrote:
>> Hello,

[...]

> Nice! I notice bootlin has worked on several BPF testing contributions,
> and was wondering if your build is some new standard buildroot/yocto
> config tailored for BPF testing, and what archs it might support? Reason
> for asking is I have a large stack of WIP patches for enabling use of
> test_progs across 64/32-bit archs and cross-compilation, and I'm keen to
> see other examples of configs, root images, etc. (especially for 32-bit)
> At the moment I'm targeting 32-bit armhf support to make progress..

No,  that's really a custom, minimal setup that I am using, based on
buildroot. My workflow is roughly the following:
- use buildroot to download an arm64 toolchain and build a minimal rootfs.
  No specific defconfig used, it is a configuration from scratch, with
  additional tools for development and debugging
- configure a kernel for arm64 testing:
$ cat tools/testing/selftest/bpf/{config,config.vm,config.aarch64} >
.config
- use the toolchain downloaded by buildroot to build the kernel
- build the selftests with the same toolchain (so I am cross-building those
  directly from my host, I am not really using vmtest)
- run all of those in qemu, and run the selftests directly with test_progs
  in there

Alexis

-- 
Alexis Lothoré, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com