Re: branch-relative-long fails on s390x host (was: [PATCH] tests/tcg/s390x: Use a different PCRel32 notation in branch-relative-long.c)

[Thomas Huth]

On 04/05/2022 11.37, Ilya Leoshkevich wrote:
> On Wed, 2022-05-04 at 11:14 +0200, Thomas Huth wrote:
> > On 04/05/2022 11.07, Ilya Leoshkevich wrote:
> > > On Wed, 2022-05-04 at 09:01 +0200, Thomas Huth wrote:
> > > > On 04/05/2022 00.46, Ilya Leoshkevich wrote:
> > > > > On Tue, 2022-05-03 at 21:26 +0200, Thomas Huth wrote:
> > > > > > On 03/05/2022 11.02, Thomas Huth wrote:
> > > > > > > On 02/05/2022 18.48, Ilya Leoshkevich wrote:
> > > > > > > > Binutils >=2.37 and Clang do not accept (. - 0x100000000)
> > > > > > > > PCRel32
> > > > > > > > constants. While this looks like a bug that needs fixing,
> > > > > > > > use
> > > > > > > > a
> > > > > > > > different notation (-0x100000000) as a workaround.
> > > > > > > >
> > > > > > > > Reported-by: Thomas Huth <thuth@redhat.com>
> > > > > > > > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> > > > > > > > ---
> > > > > > > >      tests/tcg/s390x/branch-relative-long.c | 4 ++--
> > > > > > > >      1 file changed, 2 insertions(+), 2 deletions(-)
> > > > > > > >
> > > > > > > > diff --git a/tests/tcg/s390x/branch-relative-long.c
> > > > > > > > b/tests/tcg/s390x/branch-relative-long.c
> > > > > > > > index 94219afcad..8ce9f1c2e5 100644
> > > > > > > > --- a/tests/tcg/s390x/branch-relative-long.c
> > > > > > > > +++ b/tests/tcg/s390x/branch-relative-long.c
> > > > > > > > @@ -13,8 +13,8 @@
> > > > > > > >              #_name "_end:\n");
> > > > > > > >      DEFINE_ASM(br_r14, "br %r14");
> > > > > > > > -DEFINE_ASM(brasl_r0, "brasl %r0,.-0x100000000");
> > > > > > > > -DEFINE_ASM(brcl_0xf, "brcl 0xf,.-0x100000000");
> > > > > > > > +DEFINE_ASM(brasl_r0, "brasl %r0,-0x100000000");
> > > > > > > > +DEFINE_ASM(brcl_0xf, "brcl 0xf,-0x100000000");
> > > > > > >
> > > > > > > Works for me, thanks!
> > > > > >
> > > > > > Sorry, I spoke too soon - it compiles fine, and also runs
> > > > > > fine
> > > > > > when I
> > > > > > run it
> > > > > > natively, but when I run it through "qemu-s390x", it
> > > > > > crashes...
> > > > > > does
> > > > > > that
> > > > > > work for you?
> > > > >
> > > > > Hi, yes, I just double-checked - it works fine for me.
> > > > > Could you please share the resulting test binary?
> > > >
> > > >
> > > > Sure, here it is:
> > > >
> > > > https://people.redhat.com/~thuth/data/branch-relative-long
> > > >
> > > >     Thomas
> > >
> > > Your binary worked fine for me.
> > >
> > > QEMU commit 2e3408b3cc7de4e87a9adafc8c19bfce3abec947,
> > > x86_64 host,
> >
> > Oh, well, now that you've mentioned it: I was running "make check-
> > tcg" on a
> > s390x host. It works fine on a x86, indeed. So the new problem is
> > likely in
> > the s390x TCG host backend... Richard, could you maybe have a look?
> >
> >    Thomas
>
> It worked fine on a s390x host for me as well.

Weird ... Did you compile qemu-s390x itself with Clang or with GCC? I just 
discovered that the crash also only happens if I compile qemu-s390x with 
Clang - there is no crash when I compile it with GCC.

> Can this be related to the large mmap() that the test performs?

It works when I compile the test with GCC instead of Clang - so I assume 
that the problem is somewhere else...

 Thomas