Re: [PATCH] perf s390: Fix TEXTREL in Python extension by compiling as PIC

[Ian Rogers]

On Wed, Jun 10, 2026 at 6:39 AM James Clark <james.clark@xxxxxxxxxx> wrote:
>
>
>
> On 10/06/2026 12:24 pm, Jens Remus wrote:
> > On s390 the Python extension build fails as follows when using a linker
> > that is configured to treat text relocations (TEXTREL) in shared
> > libraries as error by default:
> >
> >    GEN     python/perf.cpython-314-s390x-linux-gnu.so
> > /usr/bin/ld.bfd: error: read-only segment has dynamic relocations
> >
> > This occurrs because util/llvm-c-helpers.o is erroneously built from
> > util/llvm-c-helpers.cpp without compiler option -fPIC but linked into
> > the shared library (via libperf-util.a(perf-util-in.o)).
> >
> > On s390, object files must be compiled as position-indepedent code (PIC)
> > in order to be linked into shared libraries.  Commit a9a3f1d18a6c ("perf
> > s390: Always build with -fPIC") added compiler option -fPIC to CFLAGS
> > for s390, which is used in C compiles.  Add -fPIC to CXXFLAGS for s390
> > as well, so that it is also used in C++ compiles.
> >
> > Reported-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
> > Signed-off-by: Jens Remus <jremus@xxxxxxxxxxxxx>

Great! Perhaps we should add a fixes tag for backports. Perhaps:

Fixes: a9a3f1d18a6c ("perf s390: Always build with -fPIC")

Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks,
Ian

> > ---
> >
> > Notes (jremus):
> >      This patch applies on top of the perf-tools-next tree:
> >
> >        git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git  master
> >
> >      Note that this resolves the issue discussed in thread "[PATCH 1/1] perf
> >      build: Fix Python extension build with GCC 16 hardening":
> >      https://lore.kernel.org/all/ahV2XGx_6h7upuc3@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/T/
> >
> >   tools/perf/Makefile.config | 1 +
> >   1 file changed, 1 insertion(+)
> >
> > diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> > index 333ddd0e4bd8..33f90968c8a9 100644
> > --- a/tools/perf/Makefile.config
> > +++ b/tools/perf/Makefile.config
> > @@ -109,6 +109,7 @@ endif
> >
> >   ifeq ($(ARCH),s390)
> >     CFLAGS += -fPIC
> > +  CXXFLAGS += -fPIC
> >   endif
> >
> >   ifeq ($(ARCH),mips)
>
> Reviewed-by: James Clark <james.clark@xxxxxxxxxx>
>