Re: qemu-hppa-user: crashes immediately in hppa chroot

[Helge Deller]

On 8/29/24 04:38, Richard Henderson wrote:
> On 8/29/24 03:12, Helge Deller wrote:
> > Hi Richard,
> >
> > I tested qemu-user from v9.1-rc4 for hppa and noticed that it crashes
> > immediately when starting a hppa chroot.
> >
> > I was able to bisect the segfault back to
> > commit 081a0ed188d8d9d9038f00337d331d185a7ae331
> > Author: Richard Henderson <richard.henderson@linaro.org>
> > Date:   Wed Mar 27 13:04:00 2024 -1000
> >      target/hppa: Do not mask in copy_iaoq_entry
> >
> > This commit does not apply to git head any longer, but when I instead
> > apply this (modified) patch the segfault vanishes:
> >
> > --- a/target/hppa/translate.c
> > +++ b/target/hppa/translate.c
> > @@ -664,6 +664,11 @@ static void copy_iaoq_entry(DisasContext *ctx, TCGv_i64 
> > dest,
> >                               const DisasIAQE *src)
> >   {
> >       tcg_gen_addi_i64(dest, src->base ? : cpu_iaoq_f, src->disp);
> > +
> > +#if CONFIG_USER_ONLY
> > +    uint64_t mask = gva_offset_mask(ctx->tb_flags);
> > +    tcg_gen_andi_i64(dest, dest, mask);
> > +#endif
> >   }
> > Any idea or suggestion to fix it?
>
> More specifics are required.
>
> root@stoup:/opt/chroot/hppa/sid# ./qemu-hppa -L . ./bin/echo foo
> foo

You need to build a static binary of qemu-hppa and register it with binfmt.

On x86 debian machine I do (as root user):

modprobe binfmt_misc
echo -1 > /proc/sys/fs/binfmt_misc/qemu-hppa  # temporarily unregister hppa 
binfmt
mv -f /usr/bin/qemu-hppa-static /usr/bin/qemu-hppa-static.old # save away old 
to be able to copy new
cp build/qemu-hppa     /usr/bin/qemu-hppa-static  # COPY NEW STATIC BINARY IN 
PLACE (you need to copy yours!)
# register at binfmt:
echo ':qemu-hppa:M::'\
'\x7f\x45\x4c\x46\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x0f:'\
'\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:'\
'/usr/bin/qemu-hppa-static:POCF' > /proc/sys/fs/binfmt_misc/register


Then you should be able to chroot into your sid chroot and you should get a 
shell prompt:
chroot /opt/chroot/hppa/sid

With git head this segfaults for me.

Helge