From: Masahiro Yamada <masahiroy@kernel.org>
To: Jessica Yu <jeyu@kernel.org>
Cc: Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] kbuild: fix CONFIG_TRIM_UNUSED_KSYMS build for ppc64
Date: Fri, 12 Feb 2021 03:05:31 +0900 [thread overview]
Message-ID: <CAK7LNARa11O-N_q=m57He7G6-2tmemmhtkwN5UQu6cnf7MtZog@mail.gmail.com> (raw)
In-Reply-To: <YCUKVyMcVoNDAYJv@gunter>
On Thu, Feb 11, 2021 at 7:43 PM Jessica Yu <jeyu@kernel.org> wrote:
>
> +++ Masahiro Yamada [11/02/21 15:14 +0900]:
> >Stephen Rothwell reported a build error on ppc64 when
> >CONFIG_TRIM_UNUSED_KSYMS is enabled.
> >
> >Jessica Yu pointed out the cause of the error with the reference to the
> >ppc64 elf ABI:
> > "Symbol names with a dot (.) prefix are reserved for holding entry
> > point addresses. The value of a symbol named ".FN", if it exists,
> > is the entry point of the function "FN".
> >
> >As it turned out, CONFIG_TRIM_UNUSED_KSYMS has never worked for ppc64,
> >which has been unnoticed until recently because this option depends on
> >!UNUSED_SYMBOLS hence is disabled by all{mod,yes}config. (Then, it was
> >uncovered by another patch removing UNUSED_SYMBOLS.)
> >
> >Removing the dot prefix in scripts/gen_autoksyms.sh fixes the issue.
> >Please note it must be done before 'sort -u', because modules have
> >both ._mcount and _mcount undefined when CONFIG_FUNCTION_TRACER=y.
> >
> >Link: https://lore.kernel.org/lkml/20210209210843.3af66662@canb.auug.org.au/
> >Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
> >Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
>
> Thanks a lot for the quick fix. This fixes the ppc64 build issue on my end:
>
> Tested-by: Jessica Yu <jeyu@kernel.org>
>
> Do you plan to take this through the kbuild tree? If so, please let me
> know when you've applied it, then I can undo the temporary workaround
> I currently have in modules-next.
>
> Thank you!
>
> Jessica
Applied to linux-kbuild/fixes.
--
Best Regards
Masahiro Yamada
prev parent reply other threads:[~2021-02-11 18:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-11 6:14 [PATCH] kbuild: fix CONFIG_TRIM_UNUSED_KSYMS build for ppc64 Masahiro Yamada
2021-02-11 10:43 ` Jessica Yu
2021-02-11 18:05 ` Masahiro Yamada [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='CAK7LNARa11O-N_q=m57He7G6-2tmemmhtkwN5UQu6cnf7MtZog@mail.gmail.com' \
--to=masahiroy@kernel.org \
--cc=jeyu@kernel.org \
--cc=linux-kbuild@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=sfr@canb.auug.org.au \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.