[PATCH 1/1] perf build: Fix Python extension build with GCC 16 hardening

[PATCH 1/1] perf build: Fix Python extension build with GCC 16 hardening

[Jan Polensky]

The Python extension build fails with modern GCC versions (16+) due to
the new hardening feature that prevents dynamic relocations in read-only
segments:

  /usr/bin/ld.bfd: error: read-only segment has dynamic relocations
  collect2: error: ld returned 1 exit status

This occurs when building the perf Python bindings because the linker
enforces stricter security policies by default.

Add -Wl,-z,notext to LDSHARED to explicitly allow text relocations in
the Python extension shared object. This is necessary for the Python
C extension to link successfully while maintaining compatibility with
the Python build system.

The flag only affects the Python extension build and does not impact
the security of the main perf binary or other components.

Tested on Fedora 44 with GCC 16.1.1 20260501 (Red Hat 16.1.1-1) and
Python 3.14.4 on s390x architecture.

Reported-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Jan Polensky <japo@linux.ibm.com>
---
 tools/perf/Makefile.perf | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index bfb37f527241..12af424dd5c1 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -749,7 +749,7 @@ all: shell_compatibility_test $(ALL_PROGRAMS) $(LANG_BINDINGS) $(OTHER_PROGRAMS)
 $(shell [ -d '$(OUTPUT)python' ] || mkdir -p '$(OUTPUT)python')
 
 $(OUTPUT)python/perf$(PYTHON_EXTENSION_SUFFIX): util/python.c util/setup.py $(PERFLIBS_PY)
-	$(QUIET_GEN)LDSHARED="$(CC) -pthread -shared" \
+	$(QUIET_GEN)LDSHARED="$(CC) -pthread -shared -Wl,-z,notext" \
         CFLAGS='$(CFLAGS)' LDFLAGS='$(LDFLAGS) $(LIBS_PY)' \
 	  $(PYTHON_WORD) util/setup.py \
 	  --quiet build_ext; \
-- 
2.51.0

Re: [PATCH 1/1] perf build: Fix Python extension build with GCC 16 hardening

[Thomas Richter]

On 5/20/26 14:56, Jan Polensky wrote:
> The Python extension build fails with modern GCC versions (16+) due to
> the new hardening feature that prevents dynamic relocations in read-only
> segments:
> 
>   /usr/bin/ld.bfd: error: read-only segment has dynamic relocations
>   collect2: error: ld returned 1 exit status
> 
> This occurs when building the perf Python bindings because the linker
> enforces stricter security policies by default.
> 
> Add -Wl,-z,notext to LDSHARED to explicitly allow text relocations in
> the Python extension shared object. This is necessary for the Python
> C extension to link successfully while maintaining compatibility with
> the Python build system.
> 
> The flag only affects the Python extension build and does not impact
> the security of the main perf binary or other components.
> 
> Tested on Fedora 44 with GCC 16.1.1 20260501 (Red Hat 16.1.1-1) and
> Python 3.14.4 on s390x architecture.
> 
> Reported-by: Thomas Richter <tmricht@linux.ibm.com>
> Signed-off-by: Jan Polensky <japo@linux.ibm.com>
> ---
>  tools/perf/Makefile.perf | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
> index bfb37f527241..12af424dd5c1 100644
> --- a/tools/perf/Makefile.perf
> +++ b/tools/perf/Makefile.perf
> @@ -749,7 +749,7 @@ all: shell_compatibility_test $(ALL_PROGRAMS) $(LANG_BINDINGS) $(OTHER_PROGRAMS)
>  $(shell [ -d '$(OUTPUT)python' ] || mkdir -p '$(OUTPUT)python')
>  
>  $(OUTPUT)python/perf$(PYTHON_EXTENSION_SUFFIX): util/python.c util/setup.py $(PERFLIBS_PY)
> -	$(QUIET_GEN)LDSHARED="$(CC) -pthread -shared" \
> +	$(QUIET_GEN)LDSHARED="$(CC) -pthread -shared -Wl,-z,notext" \
>          CFLAGS='$(CFLAGS)' LDFLAGS='$(LDFLAGS) $(LIBS_PY)' \
>  	  $(PYTHON_WORD) util/setup.py \
>  	  --quiet build_ext; \

Thanks for fixing this.

Reviewed-by: Thomas Richter <tmricht@linux.ibm.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>

-- 
Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
--
IBM Deutschland Research & Development GmbH

Vorsitzender des Aufsichtsrats: Wolfgang Wendt

Geschäftsführung: David Faller

Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294