Re: [PATCH] linux-user: manage binfmt-misc preserve-arg[0] flag

[Michael Tokarev <mjt@tls.msk.ru>]

01.03.2021 14:07, John Paul Adrian Glaubitz wrote:
> On 3/1/21 11:40 AM, Michael Tokarev wrote:
>> 01.03.2021 13:35, John Paul Adrian Glaubitz wrote:
>> ..
>>> I have been trying to get qemu-user working with sbuild as it is shipped in Debian
>>> unstable now but I didn't have any success.
>>>
>>> Do you have some instructions somewhere how to get qemu-user working with sbuild?
>>
>> Have you seen #983087 which I fixed yesterday?
> 
> Thanks, but it doesn't help, unfortunately.
> 
> Do I need to use qemu-user-static or qemu-user-binfmt?

Oh. You tried to use qemu-user, not qemu-user-static..
Well.

In order for it to work it should be registered with the
in-kernel binfmt-misc subsystem. qemu-user-static package
does this automatically for you, but qemu-user does not,
for that with qemu-user you'll have to additionally install
qemu-user-binfmt package.

But I guess it wont work with qemu-user even if it is registered
(by means of installing qemu-user-binfmt or manual registration
or whatever), - because regular qemu-user binaries aren't
statically linked and hence require all the shared libraries
within the chroot in order to run.

I never tried to use regular (non-static) qemu-user with
foreign chroot, and I suspect it wont work because of that
very reason, and at least extra setup is needed (like
copying appropriate /lib/ld.so and libc&glib&Co to the
chroot).

This is all about how qemu-user works, be it debian or
any other distribution, - it is basically the same.
I can only guess the wiki page you mentioned is wrong
here.

Thanks,

/mjt