selftests/bpf: add selftest that use test_libbpf_open

This script test_libbpf.sh will be part of the 'make run_tests'
invocation, but can also be invoked manually in this directory,
and a verbose mode can be enabled via setting the environment
variable $VERBOSE like:

 $ VERBOSE=yes ./test_libbpf.sh

The script contains some tests that are commented out, as they
currently fail.  They are reminders about what we need to improve
for the libbpf loader library.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

2 files changed, 61 insertions, 2 deletions

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 3f48da0866ba..5c43c187f27c 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -13,6 +13,7 @@ endif
 CFLAGS += -Wall -O2 -I$(APIDIR) -I$(LIBDIR) -I$(GENDIR) $(GENFLAGS) -I../../../include
 LDLIBS += -lcap -lelf -lrt -lpthread
 
+# Order correspond to 'make run_tests' order
 TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \
         test_align test_verifier_log test_dev_cgroup test_tcpbpf_user
 
@@ -20,17 +21,26 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test
         test_pkt_md_access.o test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o     \
         sockmap_verdict_prog.o dev_cgroup.o sample_ret0.o test_tracepoint.o \
         test_l4lb_noinline.o test_xdp_noinline.o test_stacktrace_map.o \
-        sample_map_ret0.o test_tcpbpf_kern.o test_libbpf_open
+        sample_map_ret0.o test_tcpbpf_kern.o
 
-TEST_PROGS := test_kmod.sh test_xdp_redirect.sh test_xdp_meta.sh \
+# Order correspond to 'make run_tests' order
+TEST_PROGS := test_kmod.sh \
+        test_libbpf.sh \
+        test_xdp_redirect.sh \
+        test_xdp_meta.sh \
         test_offload.py
 
+# Compile but not part of 'make run_tests'
+TEST_GEN_PROGS_EXTENDED = test_libbpf_open
+
 include ../lib.mk
 
 BPFOBJ := $(OUTPUT)/libbpf.a cgroup_helpers.c
 
 $(TEST_GEN_PROGS): $(BPFOBJ)
 
+$(TEST_GEN_PROGS_EXTENDED): $(OUTPUT)/libbpf.a
+
 .PHONY: force
 
 # force a rebuild of BPFOBJ when its dependencies are updated
diff --git a/tools/testing/selftests/bpf/test_libbpf.sh b/tools/testing/selftests/bpf/test_libbpf.sh
new file mode 100755
index 000000000000..d97dc914cd49
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_libbpf.sh
@@ -0,0 +1,49 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+export TESTNAME=test_libbpf
+
+# Determine selftest success via shell exit code
+exit_handler()
+{
+        if (( $? == 0 )); then
+                echo "selftests: $TESTNAME [PASS]";
+        else
+                echo "$TESTNAME: failed at file $LAST_LOADED" 1>&2
+                echo "selftests: $TESTNAME [FAILED]";
+        fi
+}
+
+libbpf_open_file()
+{
+        LAST_LOADED=$1
+        if [ -n "$VERBOSE" ]; then
+            ./test_libbpf_open $1
+        else
+            ./test_libbpf_open --quiet $1
+        fi
+}
+
+# Exit script immediately (well catched by trap handler) if any
+# program/thing exits with a non-zero status.
+set -e
+
+# (Use 'trap -l' to list meaning of numbers)
+trap exit_handler 0 2 3 6 9
+
+libbpf_open_file test_l4lb.o
+
+# TODO: fix libbpf to load noinline functions
+# [warning] libbpf: incorrect bpf_call opcode
+#libbpf_open_file test_l4lb_noinline.o
+
+# TODO: fix test_xdp_meta.c to load with libbpf
+# [warning] libbpf: test_xdp_meta.o doesn't provide kernel version
+#libbpf_open_file test_xdp_meta.o
+
+# TODO: fix libbpf to handle .eh_frame
+# [warning] libbpf: relocation failed: no section(10)
+#libbpf_open_file ../../../../samples/bpf/tracex3_kern.o
+
+# Success
+exit 0