[PATCH] perf build: Specify libtraceevent dir to rpath for asan/msan build

[Yang Jihong]

perf built by asan/msan will not search for shared libraries in the
-L directory. For cross-compilation, we assume that sanitizers is
generally not enabled and add libtraceevent dir to rpath in a simple way.

1. msan build

Before:
  $ make -C tools/perf O=/tmp/perf DEBUG=1 EXTRA_CFLAGS="-O0 -g -fno-omit-frame-pointer -fsanitize=memory -fsanitize-memory-track-origins" CC=clang CXX=clang++ HOSTCC=clang NO_LIBELF=1 BUILD_BPF_SKEL=0 NO_LIBPFM=1 LIBTRACEEVENT_DIR=/opt/libtraceevent
  ...
  $ /tmp/perf/perf
  /tmp/perf/perf: error while loading shared libraries: libtraceevent.so.1: cannot open shared object file: No such file or directory

After:
  $ make -C tools/perf O=/tmp/perf DEBUG=1 EXTRA_CFLAGS="-O0 -g -fno-omit-frame-pointer -fsanitize=memory -fsanitize-memory-track-origins" CC=clang CXX=clang++ HOSTCC=clang NO_LIBELF=1 BUILD_BPF_SKEL=0 NO_LIBPFM=1 LIBTRACEEVENT_DIR=/opt/libtraceevent
  ...
  $ /tmp/perf/perf --build-options
  perf version 6.9.0-rc5
  <SNIP>
           libtraceevent: [ on  ]  # HAVE_LIBTRACEEVENT
  <SNIP>

 2. asan build

Before:
  $ make DEBUG=1 EXTRA_CFLAGS='-fno-omit-frame-pointer -fsanitize=address' LIBTRACEEVENT_DIR=/opt/libtraceevent
  ...
  $ ./perf
  ./perf: error while loading shared libraries: libtraceevent.so.1: cannot open shared object file: No such file or directory

After:
   $ make DEBUG=1 EXTRA_CFLAGS='-fno-omit-frame-pointer -fsanitize=address' LIBTRACEEVENT_DIR=/opt/libtraceevent
   ...
   $ ./perf --build-options
   perf version 6.9.0-rc5
   <SNIP>
            libtraceevent: [ on  ]  # HAVE_LIBTRACEEVENT
   <SNIP>

Signed-off-by: Yang Jihong <yangjihong@xxxxxxxxxxxxx>
---
 tools/perf/Makefile.config | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 7f1e016a9253..a9a923358604 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -188,6 +188,10 @@ TRACEEVENTLIBS := -ltraceevent
 ifdef LIBTRACEEVENT_DIR
   LIBTRACEEVENT_CFLAGS  := -I$(LIBTRACEEVENT_DIR)/include
   LIBTRACEEVENT_LDFLAGS := -L$(LIBTRACEEVENT_DIR)/lib
+  # Specify rpath for asan/msan build. Generally, cross-compilation will not enable sanitizers.
+  ifeq ($(findstring -fsanitize=,${EXTRA_CFLAGS}),-fsanitize=)
+    LIBTRACEEVENT_LDFLAGS += -Wl,-rpath,$(LIBTRACEEVENT_DIR)/lib
+  endif
 endif
 FEATURE_CHECK_CFLAGS-libtraceevent := $(LIBTRACEEVENT_CFLAGS)
 FEATURE_CHECK_LDFLAGS-libtraceevent := $(LIBTRACEEVENT_LDFLAGS) $(TRACEEVENTLIBS)
-- 
2.25.1