From: Nick Desaulniers <ndesaulniers@google.com>
To: Sedat Dilek <sedat.dilek@gmail.com>,
Masahiro Yamada <masahiroy@kernel.org>,
Jiri Olsa <jolsa@kernel.org>, Andrii Nakryiko <andrii@kernel.org>,
Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Caroline Tice <cmtice@google.com>,
Arvind Sankar <nivedita@alum.mit.edu>,
Jakub Jelinek <jakub@redhat.com>,
Fangrui Song <maskray@google.com>,
Clang-Built-Linux ML <clang-built-linux@googlegroups.com>,
Nick Clifton <nickc@redhat.com>, bpf <bpf@vger.kernel.org>
Subject: Re: [PATCH v3 0/2] Kbuild: DWARF v5 support
Date: Thu, 14 Jan 2021 10:53:06 -0800 [thread overview]
Message-ID: <CAKwvOd=+g88AEDO9JRrV-gwggsqx5p-Ckiqon3=XLcx8L-XaKg@mail.gmail.com> (raw)
In-Reply-To: <CA+icZUUtAVBvpU8M0PONnNSiOATgeL9Ym24nYUcRPoWhsQj8Ug@mail.gmail.com>
On Wed, Jan 13, 2021 at 10:18 PM Sedat Dilek <sedat.dilek@gmail.com> wrote:
>
> On Wed, Jan 13, 2021 at 11:25 PM Caroline Tice <cmtice@google.com> wrote:
> >
> > On Tue, Jan 12, 2021 at 3:17 PM Sedat Dilek <sedat.dilek@gmail.com> wrote:
> >>
> >> Unfortunately, I see with CONFIG_DEBUG_INFO_DWARF5=y and
> >> CONFIG_DEBUG_INFO_BTF=y:
> >>
> >> die__process_inline_expansion: DW_TAG_INVALID (0x48) @ <0x3f0dd5a> not handled!
> >> die__process_function: DW_TAG_INVALID (0x48) @ <0x3f0dd69> not handled!
I can confirm that I see a stream of these warnings when building with
this patch series applied, and those two configs enabled.
rebuilding with `make ... V=1`, it looks like the call to:
+ pahole -J .tmp_vmlinux.btf
is triggering these.
Shall I send a v4 that adds a Kconfig dependency on !DEBUG_INFO_BTF?
Does pahole have a bug tracker?
> >>
> >> In /usr/include/dwarf.h I found:
> >>
> >> 498: DW_OP_lit24 = 0x48, /* Literal 24. *
> >
> >
> > There are multiple dwarf objects with the value 0x48, depending on which section of the dwarf.h file you search:
> >
> > DW_TAG_call_site = 0x48
> > DW_AT_static_link = 0x48
> > DW_OP_lit24 = 0x48.
> >
> > In this case, since the error message was about a DW_TAG, it would be complaining about DW_TAG_call_site, which is new to DWARF v5.
> >
> Example for "DW_TAG_INVALID (0x48)" from my build-log:
>
> die__process_inline_expansion: DW_TAG_INVALID (0x48) @ <0x1f671e7> not handled!
>
> $ llvm-dwarfdump-11 --debug-info=0x1f671e7 vmlinux
> vmlinux: file format elf64-x86-64
>
> .debug_info contents:
>
> 0x01f671e7: DW_TAG_call_site
> DW_AT_call_return_pc (0xffffffff811b16f2)
> DW_AT_call_origin (0x01f67f1d)
>
> Looking for "DW_AT_call_origin (0x01f67f1d)":
>
> $ llvm-dwarfdump-11 --debug-info=0x01f67f1d vmlinux
> vmlinux: file format elf64-x86-64
>
> .debug_info contents:
>
> 0x01f67f1d: DW_TAG_subprogram
> DW_AT_external (true)
> DW_AT_declaration (true)
> DW_AT_linkage_name ("fput")
> DW_AT_name ("fput")
> DW_AT_decl_file
> ("/home/dileks/src/linux-kernel/git/./include/linux/file.h")
> DW_AT_decl_line (16)
> DW_AT_decl_column (0x0d)
That's a neat trick (using --debug-info=offset to print one element
from the stream).
--
Thanks,
~Nick Desaulniers
next prev parent reply other threads:[~2021-01-14 18:53 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20201204011129.2493105-1-ndesaulniers@google.com>
[not found] ` <20201204011129.2493105-3-ndesaulniers@google.com>
[not found] ` <CA+icZUVa5rNpXxS7pRsmj-Ys4YpwCxiPKfjc0Cqtg=1GDYR8-w@mail.gmail.com>
[not found] ` <CA+icZUW6h4EkOYtEtYy=kUGnyA4RxKKMuX-20p96r9RsFV4LdQ@mail.gmail.com>
[not found] ` <CABtf2+RdH0dh3NyARWSOzig8euHK33h+0jL1zsey9V1HjjzB9w@mail.gmail.com>
2021-01-14 6:18 ` [PATCH v3 0/2] Kbuild: DWARF v5 support Sedat Dilek
2021-01-14 7:09 ` Sedat Dilek
2021-01-14 9:36 ` Sedat Dilek
2021-01-14 18:53 ` Nick Desaulniers [this message]
2021-01-14 19:01 ` Nick Desaulniers
2021-01-14 19:13 ` Yonghong Song
2021-01-14 19:20 ` Nick Desaulniers
2021-01-14 20:12 ` Sedat Dilek
2021-01-14 20:11 ` Sedat Dilek
2021-01-14 21:52 ` Sedat Dilek
2021-01-14 22:05 ` Nick Desaulniers
2021-01-14 22:21 ` Sedat Dilek
2021-01-14 23:45 ` Yonghong Song
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAKwvOd=+g88AEDO9JRrV-gwggsqx5p-Ckiqon3=XLcx8L-XaKg@mail.gmail.com' \
--to=ndesaulniers@google.com \
--cc=acme@kernel.org \
--cc=andrii@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=clang-built-linux@googlegroups.com \
--cc=cmtice@google.com \
--cc=jakub@redhat.com \
--cc=jolsa@kernel.org \
--cc=masahiroy@kernel.org \
--cc=maskray@google.com \
--cc=nickc@redhat.com \
--cc=nivedita@alum.mit.edu \
--cc=sedat.dilek@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).