perf jvmti: Fix linker error when libelf config is disabled

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.

Signed-off-by: Sudeep Holla <[email protected]>
Acked-by: David Carrillo-Cisneros <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Elena Reshetova <[email protected]>
Cc: Kees Kook <[email protected]>
Cc: Paul Turner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Sudeep Holla <[email protected]>
Cc: Wang Nan <[email protected]>
Fixes: 209045adc2bb ("perf tools: add JVMTI agent library")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 100a6c1670c846f49bf79aa931b7186cef908d88..d66f90e6be5ce817602fdff7a52e5dffb34c3db0 100644 (file)
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -518,7 +518,7 @@ $(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)