Re: [PATCH dwarves] dwarf_loader: handle DWARF5 DW_OP_addrx properly

[Sedat Dilek <sedat.dilek@gmail.com>]

On Mon, Apr 5, 2021 at 8:17 AM Sedat Dilek <sedat.dilek@gmail.com> wrote:
>
> On Mon, Apr 5, 2021 at 4:31 AM Yonghong Song <yhs@fb.com> wrote:
> >
> >
> >
> > On 4/4/21 5:20 PM, Sedat Dilek wrote:
> > > On Sun, Apr 4, 2021 at 7:25 PM Sedat Dilek <sedat.dilek@gmail.com> wrote:
> > > [ ... ]
> > >>>> Yonghong Song as you described your build-environment and checking
> > >>>> requirements for clang-13 in bpf-next (see [1]), I am unsure if I want
> > >>>> to upgrade LLVM toolchain to v13-git and use bpf-next as the new
> > >>>> kernel base.
> > >>>> Lemme see if I get LLVM/Clang v13-git from Debian/experimental and/or
> > >>>> <apt.llvm.org>.
> > >>>
> > >>> If you want to run bpf-next, clang v13 definitely recommended.
> > >>> But I think if you use clang v13 to run linus linux, you may
> > >>> hit DWARF5 DW_OP_addrx as well. But unfortunately you will
> > >>> may hit a few selftest issues (e.g., BPF_TCP_CLOSE issue).
> > >>>
> > >>
> > >> OK, I started a fresh build with LLVM/Clang v13-git from <apt.llvm.org>...
> > >>
> > >> $ /usr/lib/llvm-13/bin/clang --version
> > >> Debian clang version
> > >> 13.0.0-++20210404092853+c4c511337247-1~exp1~20210404073605.3891
> > >> Target: x86_64-pc-linux-gnu
> > >> Thread model: posix
> > >> InstalledDir: /usr/lib/llvm-13/bin
> > >>
> > >> ...with latest bpf-next as new base.
> > >>
> > >> I applied your/this pahole patch "[PATCH dwarves] dwarf_loader: handle
> > >> DWARF5 DW_OP_addrx properly".
> > >>
> > >> Will report later...
> > >>
> > >
> > > Yupp, works.
> > >
> > > $ cat /proc/version
> > > Linux version 5.12.0-rc5-13-amd64-clang13-lto
> > > (sedat.dilek@gmail.com@iniza) (Debian clang version
> > > 13.0.0-++20210404092853+c4c511337247-1~exp1~20210404073605.3891, LLD
> > > 13.0.0) #13~bullseye+dileks1 SMP 2021-04-04
> > >
> > > MAKE="make V=1"
> > > MAKE_OPTS="LLVM=1 LLVM_IAS=1"
> > > MAKE_OPTS="$MAKE_OPTS PAHOLE=/opt/pahole/bin/pahole"
> > >
> > > $ LC_ALL=C $MAKE $MAKE_OPTS -C tools/testing/selftests/bpf/ 2>&1 | tee
> > > ../make-log_tools-testing-selftests-bpf_llvm-1-llvm_ias-1.txt
> > >
> > > dileks@iniza:~/src/linux-kernel/git/tools/testing/selftests/bpf$ sudo
> > > ./test_progs -n 55/2
> > > #55/2 subprog:OK
> > > #55 kfunc_call:OK
> > > Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED
> > >
> > > My linux-config and
> > > make-log_tools-testing-selftests-bpf_llvm-1_llvm_ias-1.txt.gz files
> > > are attached.
> > >
> > > Feel free to add my:
> > >
> > > Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v13-git (x86-64)
> >
> > Great! Thanks for the help to test the pahole/kernel patches.
> >
>
> Thank you Yonghong!
>
> I was able to do so with Linux v5.12-rc6 and some custom patches using
> LLVM/clang v12.0.0-rc4.
>
> Please see attachments.
>
> I applied this commit from bpf-next:
>
> commit 97a19caf1b1f6a9d4f620a9d51405a1973bd4641
> "bpf: net: Emit anonymous enum with BPF_TCP_CLOSE value explicitly"
>
> Link: https://git.kernel.org/bpf/bpf-next/c/97a19caf1b1f6a9d4f620a9d51405a1973bd4641
>
> Checking vmlinux.h:
>
> $ grep 'BPF_TCP_CLOSE ' tools/testing/selftests/bpf/tools/include/vmlinux.h
> 91929:  BPF_TCP_CLOSE = 7,
>
> Checking with test_progs:
>
> dileks@iniza:~/src/linux-kernel/git/tools/testing/selftests/bpf$ sudo
> ./test_progs -n 55/2
> #55/2 null_check:OK
> #55 ksyms_btf:OK
> Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED
>
> Can we have this patch from bpf-next for Linus Git?
>

I am awfully sorry to have sent the make-log file uncompressed
(~1.1MiB) to the list.
Mea culpa.

- Sedat -