selftests/bpf: Use un/load_bpf_testmod functions in tests

Now that we have un/load_bpf_testmod helpers in testing_helpers.h,
we can use it in other tests and save some lines.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-7-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/prog_tests/bpf_mod_race.c

@@ -11,6 +11,7 @@
 #include "ksym_race.skel.h"
 #include "bpf_mod_race.skel.h"
 #include "kfunc_call_race.skel.h"
+#include "testing_helpers.h"
 
 /* This test crafts a race between btf_try_get_module and do_init_module, and
  * checks whether btf_try_get_module handles the invocation for a well-formed
@@ -44,35 +45,10 @@ enum bpf_test_state {
 
 static _Atomic enum bpf_test_state state = _TS_INVALID;
 
-static int sys_finit_module(int fd, const char *param_values, int flags)
-{
-	return syscall(__NR_finit_module, fd, param_values, flags);
-}
-
-static int sys_delete_module(const char *name, unsigned int flags)
-{
-	return syscall(__NR_delete_module, name, flags);
-}
-
-static int load_module(const char *mod)
-{
-	int ret, fd;
-
-	fd = open("bpf_testmod.ko", O_RDONLY);
-	if (fd < 0)
-		return fd;
-
-	ret = sys_finit_module(fd, "", 0);
-	close(fd);
-	if (ret < 0)
-		return ret;
-	return 0;
-}
-
 static void *load_module_thread(void *p)
 {
 
-	if (!ASSERT_NEQ(load_module("bpf_testmod.ko"), 0, "load_module_thread must fail"))
+	if (!ASSERT_NEQ(load_bpf_testmod(false), 0, "load_module_thread must fail"))
 		atomic_store(&state, TS_MODULE_LOAD);
 	else
 		atomic_store(&state, TS_MODULE_LOAD_FAIL);
@@ -124,7 +100,7 @@ static void test_bpf_mod_race_config(const struct test_config *config)
 	if (!ASSERT_NEQ(fault_addr, MAP_FAILED, "mmap for uffd registration"))
 		return;
 
-	if (!ASSERT_OK(sys_delete_module("bpf_testmod", 0), "unload bpf_testmod"))
+	if (!ASSERT_OK(unload_bpf_testmod(false), "unload bpf_testmod"))
 		goto end_mmap;
 
 	skel = bpf_mod_race__open();
@@ -202,8 +178,8 @@ static void test_bpf_mod_race_config(const struct test_config *config)
 	bpf_mod_race__destroy(skel);
 	ASSERT_OK(kern_sync_rcu(), "kern_sync_rcu");
 end_module:
-	sys_delete_module("bpf_testmod", 0);
-	ASSERT_OK(load_module("bpf_testmod.ko"), "restore bpf_testmod");
+	unload_bpf_testmod(false);
+	ASSERT_OK(load_bpf_testmod(false), "restore bpf_testmod");
 end_mmap:
 	munmap(fault_addr, 4096);
 	atomic_store(&state, _TS_INVALID);

tools/testing/selftests/bpf/prog_tests/module_attach.c

@@ -4,6 +4,7 @@
 #include <test_progs.h>
 #include <stdbool.h>
 #include "test_module_attach.skel.h"
+#include "testing_helpers.h"
 
 static int duration;
 
@@ -32,11 +33,6 @@ static int trigger_module_test_writable(int *val)
 	return 0;
 }
 
-static int delete_module(const char *name, int flags)
-{
-	return syscall(__NR_delete_module, name, flags);
-}
-
 void test_module_attach(void)
 {
 	const int READ_SZ = 456;
@@ -93,21 +89,21 @@ void test_module_attach(void)
 	if (!ASSERT_OK_PTR(link, "attach_fentry"))
 		goto cleanup;
 
-	ASSERT_ERR(delete_module("bpf_testmod", 0), "delete_module");
+	ASSERT_ERR(unload_bpf_testmod(false), "unload_bpf_testmod");
 	bpf_link__destroy(link);
 
 	link = bpf_program__attach(skel->progs.handle_fexit);
 	if (!ASSERT_OK_PTR(link, "attach_fexit"))
 		goto cleanup;
 
-	ASSERT_ERR(delete_module("bpf_testmod", 0), "delete_module");
+	ASSERT_ERR(unload_bpf_testmod(false), "unload_bpf_testmod");
 	bpf_link__destroy(link);
 
 	link = bpf_program__attach(skel->progs.kprobe_multi);
 	if (!ASSERT_OK_PTR(link, "attach_kprobe_multi"))
 		goto cleanup;
 
-	ASSERT_ERR(delete_module("bpf_testmod", 0), "delete_module");
+	ASSERT_ERR(unload_bpf_testmod(false), "unload_bpf_testmod");
 	bpf_link__destroy(link);
 
 cleanup:

tools/testing/selftests/bpf/testing_helpers.c

@@ -338,21 +338,22 @@ static int delete_module(const char *name, int flags)
 	return syscall(__NR_delete_module, name, flags);
 }
 
-void unload_bpf_testmod(bool verbose)
+int unload_bpf_testmod(bool verbose)
 {
 	if (kern_sync_rcu())
 		fprintf(stdout, "Failed to trigger kernel-side RCU sync!\n");
 	if (delete_module("bpf_testmod", 0)) {
 		if (errno == ENOENT) {
 			if (verbose)
 				fprintf(stdout, "bpf_testmod.ko is already unloaded.\n");
-			return;
+			return -1;
 		}
 		fprintf(stdout, "Failed to unload bpf_testmod.ko from kernel: %d\n", -errno);
-		return;
+		return -1;
 	}
 	if (verbose)
 		fprintf(stdout, "Successfully unloaded bpf_testmod.ko.\n");
+	return 0;
 }
 
 int load_bpf_testmod(bool verbose)

tools/testing/selftests/bpf/testing_helpers.h

@@ -30,7 +30,7 @@ int parse_test_list_file(const char *path,
 
 __u64 read_perf_max_sample_freq(void);
 int load_bpf_testmod(bool verbose);
-void unload_bpf_testmod(bool verbose);
+int unload_bpf_testmod(bool verbose);
 int kern_sync_rcu(void);
 
 #endif /* __TESTING_HELPERS_H */