[PATCH 5.12 284/363] perf tools: Fix dynamic libbpf link

[Greg Kroah-Hartman]

From: Jiri Olsa <jolsa@xxxxxxxxxx>

[ Upstream commit ad1237c30d975535a669746496cbed136aa5a045 ]

Justin reported broken build with LIBBPF_DYNAMIC=1.

When linking libbpf dynamically we need to use perf's
hashmap object, because it's not exported in libbpf.so
(only in libbpf.a).

Following build is now passing:

  $ make LIBBPF_DYNAMIC=1
    BUILD:   Doing 'make -j8' parallel build
    ...
  $ ldd perf | grep libbpf
        libbpf.so.0 => /lib64/libbpf.so.0 (0x00007fa7630db000)

Fixes: eee19501926d ("perf tools: Grab a copy of libbpf's hashmap")
Reported-by: Justin M. Forbes <jforbes@xxxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Michael Petlan <mpetlan@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lore.kernel.org/lkml/20210508205020.617984-1-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 tools/perf/Makefile.config | 1 +
 tools/perf/util/Build      | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index d8e59d31399a..c955cd683e22 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -530,6 +530,7 @@ ifndef NO_LIBELF
       ifdef LIBBPF_DYNAMIC
         ifeq ($(feature-libbpf), 1)
           EXTLIBS += -lbpf
+          $(call detected,CONFIG_LIBBPF_DYNAMIC)
         else
           dummy := $(error Error: No libbpf devel library found, please install libbpf-devel);
         endif
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index e3e12f9d4733..5a296ac69415 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -141,7 +141,14 @@ perf-$(CONFIG_LIBELF) += symbol-elf.o
 perf-$(CONFIG_LIBELF) += probe-file.o
 perf-$(CONFIG_LIBELF) += probe-event.o
 
+ifdef CONFIG_LIBBPF_DYNAMIC
+  hashmap := 1
+endif
 ifndef CONFIG_LIBBPF
+  hashmap := 1
+endif
+
+ifdef hashmap
 perf-y += hashmap.o
 endif
 
-- 
2.30.2