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

From: Greg Kroah-Hartman
Date: Mon May 17 2021 - 10:36:34 EST


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