On Dec 3, 2025, at 11:43 AM, Arnaldo Carvalho de Melo acme@kernel.org wrote:
On Tue, Dec 02, 2025 at 08:55:26PM -0700, Jon Kohler wrote:
Fix Makefile.perf to ensure that bpf skeletons are built with fPIC.
When building with BUILD_BPF_SKEL=1, bpf_skel's was not getting built with fPIC, seeing compilation failures like:
/usr/bin/ld: /builddir/.../tools/perf/util/bpf_skel/.tmp/bootstrap/main.o: relocation R_X86_64_32 against `.rodata.str1.8' can not be used when making a PIE object; recompile with -fPIE
Bisected down to 6.18 commit a39516805992 ("tools build: Don't assume libtracefs-devel is always available").
Fixes: a39516805992 ("tools build: Don't assume libtracefs-devel is always available")
How come, this patch is just:
It doesn’t make sense to me, but I checked the results of the bisection by hand and, hand-to-god, reverting commit a39516805992 unbreaks our build every single time. Putting a39516805992 back breaks our build 100% of the time.
diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature index 9c1a69d26f5121fd..531f8fc4f7df9943 100644 --- a/tools/build/Makefile.feature +++ b/tools/build/Makefile.feature @@ -83,7 +83,6 @@ FEATURE_TESTS_BASIC := \ libpython \ libslang \ libtraceevent \
libtracefs \ libcpupower \ pthread-attr-setaffinity-np \ pthread-barrier \diff --git a/tools/build/feature/test-all.c b/tools/build/feature/test-all.c index e1847db6f8e63750..2df593593b6ec15e 100644 --- a/tools/build/feature/test-all.c +++ b/tools/build/feature/test-all.c @@ -150,10 +150,6 @@ # include "test-libtraceevent.c" #undef main
-#define main main_test_libtracefs -# include "test-libtracefs.c" -#undef main
int main(int argc, char *argv[]) { main_test_libpython(); @@ -187,7 +183,6 @@ int main(int argc, char *argv[]) main_test_reallocarray(); main_test_libzstd(); main_test_libtraceevent();
main_test_libtracefs(); return 0;}
And your patch is touching building bpftool? Seems very unrelated :-\
- Arnaldo
Cc: stable@vger.kernel.org Signed-off-by: Jon Kohler jon@nutanix.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 02f87c49801f..4557c2e89e88 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -1211,7 +1211,7 @@ endif
$(BPFTOOL): | $(SKEL_TMP_OUT) $(Q)CFLAGS= $(MAKE) -C ../bpf/bpftool \
- OUTPUT=$(SKEL_TMP_OUT)/ bootstrap
- EXTRA_CFLAGS="-fPIC" OUTPUT=$(SKEL_TMP_OUT)/ bootstrap
# Paths to search for a kernel to generate vmlinux.h from. VMLINUX_BTF_ELF_PATHS ?= $(if $(O),$(O)/vmlinux) \ -- 2.43.0