Re: [PATCH bpf] selftests: bpf: check map in map pruning

[Ilya Leoshkevich <iii@linux.ibm.com>]

On Wed, 2021-11-17 at 17:38 -0800, Andrii Nakryiko wrote:
> On Wed, Nov 17, 2021 at 5:29 PM Andrii Nakryiko
> <andrii.nakryiko@gmail.com> wrote:
> > 
> > On Wed, Nov 17, 2021 at 5:01 PM Alexei Starovoitov
> > <alexei.starovoitov@gmail.com> wrote:
> > > 
> > > On Wed, Nov 17, 2021 at 08:47:45AM +0000, Lorenz Bauer wrote:
> > > > On Sat, 13 Nov 2021 at 01:27, Alexei Starovoitov
> > > > <alexei.starovoitov@gmail.com> wrote:
> > > > > 
> > > > > Not sure how you've tested it, but it doesn't work in unpriv:
> > > > > $ test_verifier 789
> > > > > #789/u map in map state pruning FAIL
> > > > > processed 26 insns (limit 1000000) max_states_per_insn 0
> > > > > total_states
> > > > > 2 peak_states 2 mark_read 1
> > > > > #789/p map in map state pruning OK
> > > > 
> > > > Strange, I have a script that I use for bisecting which uses a
> > > > minimal
> > > > .config + virtue to run a vm, plus I was debugging in gdb at the
> > > > same
> > > > time. I might have missed this, apologies.
> > > > 
> > > > I guess vmtest.sh is the canonical way to run tests now?
> > > 
> > > vmtest.sh runs test_progs only. That's the minimum bar that
> > 
> > It runs test_progs by default, unless something else is requested.
> > You
> > can run anything inside it, e.g.:
> > 
> > ./vmtest.sh -- ./test_maps
> > 
> > BTW, we recently moved configs around in libbpf repo on Github, so
> > this script broke. I'm sending a fix in a few minutes, hopefully.
> 
> ... and of course it's not that simple. [0] recently changed how we
> build qemu image and vmtest.sh had some assumptions. Some trivial
> things I fixed, but I'm not too familiar with the init scripts stuff.
> Adding Ilya and KP to hopefully help with this. Ilya, KP, can you
> please help restore vmtest.sh functionality?
> 
> After fixing few paths:
> 
> diff --git a/tools/testing/selftests/bpf/vmtest.sh
> b/tools/testing/selftests/bpf/vmtest.sh
> index 027198768fad..7ea40108b85d 100755
> --- a/tools/testing/selftests/bpf/vmtest.sh
> +++ b/tools/testing/selftests/bpf/vmtest.sh
> @@ -13,8 +13,8 @@ DEFAULT_COMMAND="./test_progs"
>  MOUNT_DIR="mnt"
>  ROOTFS_IMAGE="root.img"
>  OUTPUT_DIR="$HOME/.bpf_selftests"
> -
> KCONFIG_URL="https://raw.githubusercontent.com/libbpf/libbpf/master/travis-ci/vmtest/configs/latest.config
> "
> -
> KCONFIG_API_URL="https://api.github.com/repos/libbpf/libbpf/contents/travis-ci/vmtest/configs/latest.config
> "
> +KCONFIG_URL="https://raw.githubusercontent.com/libbpf/libbpf/master/travis-ci/vmtest/configs/config-latest.x86_64
> "
> +KCONFIG_API_URL="https://api.github.com/repos/libbpf/libbpf/contents/travis-ci/vmtest/configs/config-latest.x86_64
> "
>  INDEX_URL="https://raw.githubusercontent.com/libbpf/libbpf/master/travis-ci/vmtest/configs/INDEX
> "
>  NUM_COMPILE_JOBS="$(nproc)"
>  LOG_FILE_BASE="$(date +"bpf_selftests.%Y-%m-%d_%H-%M-%S")"
> @@ -85,7 +85,7 @@ newest_rootfs_version()
>  {
>         {
>         for file in "${!URLS[@]}"; do
> -               if [[ $file =~ ^libbpf-vmtest-rootfs-(.*)\.tar\.zst$
> ]]; then
> +               if [[ $file =~
> ^x86_64/libbpf-vmtest-rootfs-(.*)\.tar\.zst$ ]]; then
>                         echo "${BASH_REMATCH[1]}"
>                 fi
>         done
> 
> ... the next problem is more severe. Script complains about missing
> /etc/rcS.d, if I just force-created it, when kernel boots we get:
> 
> 
> [    1.050803] ---[ end Kernel panic - not syncing: No working init
> found.  Try passing init= option to kernel. See Linux
> Documentation/admin-guide/init.rst for guidance. ]---
> 
> 
> Please help.
> 
>   [0] https://github.com/libbpf/libbpf/pull/204

I've posted a fix, please give it a try:

https://lore.kernel.org/bpf/20211118115225.1349726-1-iii@linux.ibm.com/

Missing was the ${ARCH} prefix when downloading the image, so it ended
up being empty. Now your ~/.bpf_selftests is poisoned with it, so
you'll need to run vmtest.sh with -i switch once in order to remove the
bad image.

Best regards,
Ilya