[PATCH 1/2] tools: perf: fix linker error when libelf config is disabled

[Sudeep Holla]

When libelf is disabled in the configuration, we get the following
linker error:
  LINK     libperf-jvmti.so
  ld: cannot find -lelf
  Makefile.perf:515: recipe for target 'libperf-jvmti.so' failed

Jiri pointed out that both librt and libelf are not really required. So
this patch fixes the linker error by getting rid of unwanted libraries
in the linker stage.

Fixes: 209045adc2bb ("perf tools: add JVMTI agent library")
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
---
 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 8fc24824705e..9e4a7ea84637 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -512,7 +512,7 @@ $(LIBJVMTI_IN): FORCE
 	$(Q)$(MAKE) -f $(srctree)/tools/build/Makefile.build dir=jvmti obj=jvmti
 
 $(OUTPUT)$(LIBJVMTI): $(LIBJVMTI_IN)
-	$(QUIET_LINK)$(CC) -shared -Wl,-soname -Wl,$(LIBJVMTI) -o $@ $< -lelf -lrt
+	$(QUIET_LINK)$(CC) -shared -Wl,-soname -Wl,$(LIBJVMTI) -o $@ $<
 endif
 
 $(patsubst perf-%,%.o,$(PROGRAMS)): $(wildcard */*.h)
-- 
2.7.4