mailing list of musl libc
 help / color / mirror / code / Atom feed
From: Ariadne Conill <ariadne@dereferenced.org>
To: musl@lists.openwall.com
Subject: Re: [musl] friendly errors for ABI mismatch
Date: Mon, 27 Jul 2020 14:57:10 -0600	[thread overview]
Message-ID: <2983406.IqFZyr3sfq@localhost> (raw)
In-Reply-To: <20200727160326.GN6949@brightrain.aerifal.cx>

Hello,

On Monday, July 27, 2020 10:03:30 AM MDT Rich Felker wrote:
> On Mon, Jul 27, 2020 at 09:27:28AM -0600, Ariadne Conill wrote:
> > Hello,
> > 
> > On 32-bit systems, musl 1.2 has a new ABI (due to time64).  This results
> > in
> > programs built against musl 1.2 failing to run against musl 1.1.  That
> > part is fine, but you get an error message about being unable to relocate
> > symbols, which is not really insightful if you don't know about the ABI
> > break.
> > 
> > glibc, on the other hand, has a minimum version specified in every binary,
> > and prints an error message saying the glibc is too old if this situation
> > is encountered.
> > 
> > I think we should add this feature to musl, so that in the future if we
> > have another ABI break, users will be given useful advice about how to
> > fix it.  Due to the relocation error message, a few Alpine contributors
> > have been tripped up while trying to debug their work...
> 
> What you're seeing here is just a special case of the general property
> that, if you've linked to a version of libc (or any library) that has
> a new symbol and attempt to run with an older version, you'll get a
> missing symbol error. It's very intentional (see libc comparison and
> "forward compatibility") that we don't encode "minimum version number"
> required anywhere. If you attempt to run with a library that has all
> the symbols, it will run, subject to any bugs in the library version
> you have and any functionality that returns with failure because it's
> not supported in the version you have, etc.
> 
> There is no way to give a more high-level reason for the runtime link
> failure like "your program needs time64 and you're running with an old
> musl" because the code reporting the error *is the old musl* that's
> not aware of whatever it is that the new binary is missing. Maybe you
> have something else in mind that I don't fully understand, but
> whatever it is it would only address future missing symbol errors, not
> the ones you're seeing right now.

Simply what I have in mind is having friendly errors in the future, obviously 
we cannot do it with time64.

Ariadne



  parent reply	other threads:[~2020-07-27 20:57 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-27 15:27 Ariadne Conill
2020-07-27 16:03 ` Rich Felker
2020-07-27 20:54   ` A. Wilcox
2020-07-27 20:57   ` Ariadne Conill [this message]
2020-07-27 21:50     ` Rich Felker
2020-07-28  8:40       ` Florian Weimer
2020-07-29  1:16         ` Rich Felker
2020-07-27 21:16 ` Florian Weimer

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=2983406.IqFZyr3sfq@localhost \
    --to=ariadne@dereferenced.org \
    --cc=musl@lists.openwall.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.
Code repositories for project(s) associated with this public inbox

	https://git.vuxu.org/mirror/musl/

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).