This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: /usr/bin/m4: internal error detected
- From: John Paul Adrian Glaubitz <glaubitz at physik dot fu-berlin dot de>
- To: Andreas Schwab <schwab at linux-m68k dot org>
- Cc: Daniel Kahn Gillmor <dkg at fifthhorseman dot net>, bug-m4 at gnu dot org, debian-superh at lists dot debian dot org, libc-alpha at sourceware dot org, QEMU Developers <qemu-devel at nongnu dot org>
- Date: Fri, 1 Dec 2017 13:22:20 +0100
- Subject: Re: /usr/bin/m4: internal error detected
- Authentication-results: sourceware.org; auth=none
- References: <87po7zrq65.fsf@fifthhorseman.net> <f5f44f70-d274-e7a6-618e-8906f58a9073@physik.fu-berlin.de> <871ske63pu.fsf@linux-m68k.org>
On 12/01/2017 01:18 PM, Andreas Schwab wrote:
This isn't a bug in m4 or anything architecture-specific, it's a regression
that was introduced by an upstream change in glibc [1] and mainly affects
qemu-user which we are using for m68k and sh4 [2].
It's a bug in qemu-linux-user, which ignores CLONE_VFORK, turning vfork
into fork. This breaks the expected semantics of vfork (VM sharing and
blocking the child until exec).
Yes, I wasn't really arguing that it's a bug in QEMU as Adhemerval had already
explained. The problem was just that apparently resolving the issue in
QEMU isn't trivial as Peter Maydell mentioned in [1].
That's why I was looking for a workaround. However, I have re-tested Florian's
patch and it works for me now, it didn't when I tested it for the first time.
So, we have a workaround for the time being until the bug is resolved in QEMU.
Adrian
[1] https://bugs.launchpad.net/qemu/+bug/1673976
--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer - glaubitz@debian.org
`. `' Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
`- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913