Netdev Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Yonghong Song <yhs@fb.com>
To: Jiri Olsa <jolsa@kernel.org>, Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>
Cc: Mark Wielaard <mjw@redhat.com>, Nick Clifton <nickc@redhat.com>,
	Jesper Dangaard Brouer <brouer@redhat.com>,
	<netdev@vger.kernel.org>, <bpf@vger.kernel.org>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Andrii Nakryiko <andriin@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@chromium.org>
Subject: Re: [PATCH bpf-next] tools/resolve_btfids: Fix sections with wrong alignment
Date: Wed, 19 Aug 2020 14:32:19 -0700	[thread overview]
Message-ID: <24314022-71a2-bd9a-17c0-325b20386ff7@fb.com> (raw)
In-Reply-To: <20200819092342.259004-1-jolsa@kernel.org>



On 8/19/20 2:23 AM, Jiri Olsa wrote:
> The data of compressed section should be aligned to 4
> (for 32bit) or 8 (for 64 bit) bytes.
> 
> The binutils ld sets sh_addralign to 1, which makes libelf
> fail with misaligned section error during the update as
> reported by Jesper:
> 
>     FAILED elf_update(WRITE): invalid section alignment
> 
> While waiting for ld fix, we can fix compressed sections
> sh_addralign value manually.
> 
> Adding warning in -vv mode when the fix is triggered:
> 
>    $ ./tools/bpf/resolve_btfids/resolve_btfids -vv vmlinux
>    ...
>    section(36) .comment, size 44, link 0, flags 30, type=1
>    section(37) .debug_aranges, size 45684, link 0, flags 800, type=1
>     - fixing wrong alignment sh_addralign 16, expected 8
>    section(38) .debug_info, size 129104957, link 0, flags 800, type=1
>     - fixing wrong alignment sh_addralign 1, expected 8
>    section(39) .debug_abbrev, size 1152583, link 0, flags 800, type=1
>     - fixing wrong alignment sh_addralign 1, expected 8
>    section(40) .debug_line, size 7374522, link 0, flags 800, type=1
>     - fixing wrong alignment sh_addralign 1, expected 8
>    section(41) .debug_frame, size 702463, link 0, flags 800, type=1
>    section(42) .debug_str, size 1017571, link 0, flags 830, type=1
>     - fixing wrong alignment sh_addralign 1, expected 8
>    section(43) .debug_loc, size 3019453, link 0, flags 800, type=1
>     - fixing wrong alignment sh_addralign 1, expected 8
>    section(44) .debug_ranges, size 1744583, link 0, flags 800, type=1
>     - fixing wrong alignment sh_addralign 16, expected 8
>    section(45) .symtab, size 2955888, link 46, flags 0, type=2
>    section(46) .strtab, size 2613072, link 0, flags 0, type=3
>    ...
>    update ok for vmlinux
> 
> Another workaround is to disable compressed debug info data
> CONFIG_DEBUG_INFO_COMPRESSED kernel option.
> 
> Fixes: fbbb68de80a4 ("bpf: Add resolve_btfids tool to resolve BTF IDs in ELF object")
> Cc: Mark Wielaard <mjw@redhat.com>
> Cc: Nick Clifton <nickc@redhat.com>
> Reported-by: Jesper Dangaard Brouer <brouer@redhat.com>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>

Acked-by: Yonghong Song <yhs@fb.com>

      parent reply	other threads:[~2020-08-19 21:32 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-19  9:23 Jiri Olsa
2020-08-19 15:31 ` Yonghong Song
2020-08-19 17:36   ` Jiri Olsa
2020-08-19 18:16     ` Nick Desaulniers
2020-08-19 21:30       ` Yonghong Song
2020-08-20  2:27         ` Fāng-ruì Sòng
2020-08-20  3:23           ` Yonghong Song
2020-08-20 10:18             ` Jiri Olsa
2020-08-20 10:18             ` Mark Wielaard
2020-08-20 15:51               ` Yonghong Song
2020-08-20 17:36                 ` Mark Wielaard
2020-08-20 17:54                   ` Yonghong Song
2020-08-20 21:24                     ` Alexei Starovoitov
2020-08-19 17:02 ` Jesper Dangaard Brouer
2020-08-19 21:32 ` Yonghong Song [this message]

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=24314022-71a2-bd9a-17c0-325b20386ff7@fb.com \
    --to=yhs@fb.com \
    --cc=andriin@fb.com \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=brouer@redhat.com \
    --cc=daniel@iogearbox.net \
    --cc=john.fastabend@gmail.com \
    --cc=jolsa@kernel.org \
    --cc=kafai@fb.com \
    --cc=kpsingh@chromium.org \
    --cc=mjw@redhat.com \
    --cc=netdev@vger.kernel.org \
    --cc=nickc@redhat.com \
    --cc=songliubraving@fb.com \
    --subject='Re: [PATCH bpf-next] tools/resolve_btfids: Fix sections with wrong alignment' \
    /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

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).