Le 09/07/2019 à 14:16, Peter Maydell a écrit :
> Is the proposed patch backwards compatible (ie "old QEMU binary works
> with newer binfmt-misc registration" and "new QEMU binary works with
> older binfmt-misc registration") ? Because binfmt-misc stuff is whole-
> system but QEMU binaries are per-chroot, this kind of thing is awkward
> to change if we don't have back-compat (and typically the kernel
> semantics for these things often don't allow back-compat or any kind of
> migration-path to the new better setup :-( )
>
If you don't enable the preserve-arg[0] flag, old and new QEMU will
work.
If you enable the flag, only new QEMU with -0/QEMU_ARGV0 will work.
The best solution would be to force preserve-arg[0] with open-binary
flag and rely on AT_FDEXEC to detect the binfmt-misc environment, but
this breaks compatibility with existing environment and old QEMU.
Regarding the "binfmt-misc stuff is whole-system" problem, I've proposed
months ago a kernel based solution [1] to have a configuration per
namespace (chroot), but no one seems really interested (I think
maintainer is afraid by potential security issues).
[1] ns: introduce binfmt_misc namespace
https://patchwork.kernel.org/cover/10634807/
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1835839
Title:
qemu-user: $0 incorrectly always reports absolute path
Status in QEMU:
New
Bug description:
We just ran into an issue with the Perl package on Debian/m68k when
being built with qemu-user [1].
The problem can be boiled down to qemu-user always reporting absolute
paths for the shell variable $0 no matter on how the command was
invoked.
A simple reproducer is this:
On normal system (no emulation):
root@nofan:~> sh -c 'echo $0'
sh
root@nofan:~>
On qemu-user:
(sid-m68k-sbuild)root@nofan:/# sh -c 'echo $0'
/bin/sh
(sid-m68k-sbuild)root@nofan:/#
> [1] https://lists.debian.org/debian-68k/2019/07/msg00007.html
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1835839/+subscriptions
