[PATCH bpf-next v2 1/6] selftests/bpf: test_progs: add test__join_cgroup helper

[Stanislav Fomichev]

test__join_cgroup() combines the following operations that usually
go hand in hand and returns cgroup fd:

  * setup cgroup environment (make sure cgroupfs is mounted)
  * mkdir cgroup
  * join cgroup

It also marks a test as a "cgroup cleanup needed" and removes cgroup
state after the test is done.

Signed-off-by: Stanislav Fomichev <s...@google.com>
---
 tools/testing/selftests/bpf/Makefile     |  4 +--
 tools/testing/selftests/bpf/test_progs.c | 38 ++++++++++++++++++++++++
 tools/testing/selftests/bpf/test_progs.h |  1 +
 3 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/Makefile 
b/tools/testing/selftests/bpf/Makefile
index c7595b4ed55d..e145954d3765 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -102,7 +102,7 @@ $(OUTPUT)/test_socket_cookie: cgroup_helpers.c
 $(OUTPUT)/test_sockmap: cgroup_helpers.c
 $(OUTPUT)/test_tcpbpf_user: cgroup_helpers.c
 $(OUTPUT)/test_tcpnotify_user: cgroup_helpers.c trace_helpers.c
-$(OUTPUT)/test_progs: trace_helpers.c
+$(OUTPUT)/test_progs: cgroup_helpers.c trace_helpers.c
 $(OUTPUT)/get_cgroup_id_user: cgroup_helpers.c
 $(OUTPUT)/test_cgroup_storage: cgroup_helpers.c
 $(OUTPUT)/test_netcnt: cgroup_helpers.c
@@ -196,7 +196,7 @@ $(ALU32_BUILD_DIR)/test_progs_32: test_progs.c 
$(OUTPUT)/libbpf.a\
                                                | $(ALU32_BUILD_DIR)
        $(CC) $(TEST_PROGS_CFLAGS) $(CFLAGS) \
                -o $(ALU32_BUILD_DIR)/test_progs_32 \
-               test_progs.c test_stub.c trace_helpers.c prog_tests/*.c \
+               test_progs.c test_stub.c cgroup_helpers.c trace_helpers.c 
prog_tests/*.c \
                $(OUTPUT)/libbpf.a $(LDLIBS)
 
 $(ALU32_BUILD_DIR)/test_progs_32: $(PROG_TESTS_H)
diff --git a/tools/testing/selftests/bpf/test_progs.c 
b/tools/testing/selftests/bpf/test_progs.c
index e8616e778cb5..af75a1c7a458 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -2,6 +2,7 @@
 /* Copyright (c) 2017 Facebook
  */
 #include "test_progs.h"
+#include "cgroup_helpers.h"
 #include "bpf_rlimit.h"
 #include <argp.h>
 #include <string.h>
@@ -17,6 +18,7 @@ struct prog_test_def {
        int error_cnt;
        int skip_cnt;
        bool tested;
+       bool need_cgroup_cleanup;
 
        const char *subtest_name;
        int subtest_num;
@@ -122,6 +124,39 @@ void test__fail(void)
        env.test->error_cnt++;
 }
 
+int test__join_cgroup(const char *path)
+{
+       int fd;
+
+       if (!env.test->need_cgroup_cleanup) {
+               if (setup_cgroup_environment()) {
+                       fprintf(stderr,
+                               "#%d %s: Failed to setup cgroup environment\n",
+                               env.test->test_num, env.test->test_name);
+                       return -1;
+               }
+
+               env.test->need_cgroup_cleanup = true;
+       }
+
+       fd = create_and_get_cgroup(path);
+       if (fd < 0) {
+               fprintf(stderr,
+                       "#%d %s: Failed to create cgroup '%s' (errno=%d)\n",
+                       env.test->test_num, env.test->test_name, path, errno);
+               return fd;
+       }
+
+       if (join_cgroup(path)) {
+               fprintf(stderr,
+                       "#%d %s: Failed to join cgroup '%s' (errno=%d)\n",
+                       env.test->test_num, env.test->test_name, path, errno);
+               return -1;
+       }
+
+       return fd;
+}
+
 struct ipv4_packet pkt_v4 = {
        .eth.h_proto = __bpf_constant_htons(ETH_P_IP),
        .iph.ihl = 5,
@@ -530,6 +565,9 @@ int main(int argc, char **argv)
                fprintf(env.stdout, "#%d %s:%s\n",
                        test->test_num, test->test_name,
                        test->error_cnt ? "FAIL" : "OK");
+
+               if (test->need_cgroup_cleanup)
+                       cleanup_cgroup_environment();
        }
        stdio_restore();
        printf("Summary: %d/%d PASSED, %d SKIPPED, %d FAILED\n",
diff --git a/tools/testing/selftests/bpf/test_progs.h 
b/tools/testing/selftests/bpf/test_progs.h
index c8edb9464ba6..e518bd5da3e2 100644
--- a/tools/testing/selftests/bpf/test_progs.h
+++ b/tools/testing/selftests/bpf/test_progs.h
@@ -71,6 +71,7 @@ extern void test__force_log();
 extern bool test__start_subtest(const char *name);
 extern void test__skip(void);
 extern void test__fail(void);
+extern int test__join_cgroup(const char *path);
 
 #define MAGIC_BYTES 123
 
-- 
2.23.0.187.g17f5b7556c-goog