From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] ftrace: Do not reference symbols in sections without size
Date: Tue, 16 Feb 2021 09:45:39 -0600 [thread overview]
Message-ID: <20210216154539.qac763oef4czrtss@treble> (raw)
In-Reply-To: <20210216095121.4fe321dc@gandalf.local.home>
On Tue, Feb 16, 2021 at 09:51:21AM -0500, Steven Rostedt wrote:
> On Tue, 16 Feb 2021 12:04:06 +0100
> Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:
>
> > Thanks for this.
> >
> > Should I also queue these up for 4.9 and 4.14 which do not have these
> > commits in them either (but somehow do not show the problem, yet)?
>
> This bothers me. I want to know exactly why this is a problem.
I actually see the same problem with 4.9 and 4.14, using the same
config.
It's very config-specific. Something has to convince the toolchain to
not reference those two weak functions by section.
> That said, it is fine to backport those patches, and I would include 4.9
> and 4.14, as I would think you have a similar requirement that we have in
> the stable-rt trees. That is you shouldn't experience a regression going
> from an older kernel to a newer one because the older one had a fix
> backported to it that a newer one did not. Basically the same rationale that
> all fixes go into Linus's tree before backporting. We do the same on the
> stable-rt, where all fixes go in all maintained stable trees that are newer
> than the one you are backporting to.
>
> Although, it does allow more to be traced than what recordmcount enables.
> But hopefully it doesn't cause any issues. Maybe I should do some ftrace
> testing before you go and release any of those stables with those patches.
>
> I'm looking to see if this new "feature" of binutils isn't causing trouble
> elsewhere. I'm thinking that ftrace is just the canary here.
It already caused quite a bit of trouble with objtool (as did a previous
similar change by the Clang assembler).
--
Josh
next prev parent reply other threads:[~2021-02-16 15:47 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-15 21:44 Steven Rostedt
2021-02-16 0:05 ` Josh Poimboeuf
2021-02-16 1:06 ` Steven Rostedt
2021-02-16 2:00 ` Steven Rostedt
2021-02-16 11:04 ` Greg Kroah-Hartman
2021-02-16 14:51 ` Steven Rostedt
2021-02-16 15:45 ` Josh Poimboeuf [this message]
2021-02-16 15:54 ` Greg Kroah-Hartman
2021-02-16 17:53 ` Steven Rostedt
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=20210216154539.qac763oef4czrtss@treble \
--to=jpoimboe@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=rostedt@goodmis.org \
/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
all inboxes | Powered by JetHome®