selftests/bpf: Move test_progs helpers to testing_helpers object

Moving test_progs helpers to testing_helpers object so they can be
used from test_verifier in following changes.

Also adding missing ifndef header guard to testing_helpers.h header.

Using stderr instead of env.stderr because un/load_bpf_testmod helpers
will be used outside test_progs. Also at the point of calling them
in test_progs the std files are not hijacked yet and stderr is the
same as env.stderr.
Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-4-jolsa@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/test_progs.c

@@ -11,7 +11,6 @@
 #include <signal.h>
 #include <string.h>
 #include <execinfo.h> /* backtrace */
-#include <linux/membarrier.h>
 #include <sys/sysinfo.h> /* get_nprocs */
 #include <netinet/in.h>
 #include <sys/select.h>
@@ -629,68 +628,6 @@ int compare_stack_ips(int smap_fd, int amap_fd, int stack_trace_len)
 	return err;
 }
 
-static int finit_module(int fd, const char *param_values, int flags)
-{
-	return syscall(__NR_finit_module, fd, param_values, flags);
-}
-
-static int delete_module(const char *name, int flags)
-{
-	return syscall(__NR_delete_module, name, flags);
-}
-
-/*
- * Trigger synchronize_rcu() in kernel.
- */
-int kern_sync_rcu(void)
-{
-	return syscall(__NR_membarrier, MEMBARRIER_CMD_SHARED, 0, 0);
-}
-
-static void unload_bpf_testmod(void)
-{
-	if (kern_sync_rcu())
-		fprintf(env.stderr, "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;
-		}
-		fprintf(env.stderr, "Failed to unload bpf_testmod.ko from kernel: %d\n", -errno);
-		return;
-	}
-	if (verbose())
-		fprintf(stdout, "Successfully unloaded bpf_testmod.ko.\n");
-}
-
-static int load_bpf_testmod(void)
-{
-	int fd;
-
-	/* ensure previous instance of the module is unloaded */
-	unload_bpf_testmod();
-
-	if (verbose())
-		fprintf(stdout, "Loading bpf_testmod.ko...\n");
-
-	fd = open("bpf_testmod.ko", O_RDONLY);
-	if (fd < 0) {
-		fprintf(env.stderr, "Can't find bpf_testmod.ko kernel module: %d\n", -errno);
-		return -ENOENT;
-	}
-	if (finit_module(fd, "", 0)) {
-		fprintf(env.stderr, "Failed to load bpf_testmod.ko into the kernel: %d\n", -errno);
-		close(fd);
-		return -EINVAL;
-	}
-	close(fd);
-
-	if (verbose())
-		fprintf(stdout, "Successfully loaded bpf_testmod.ko.\n");
-	return 0;
-}
-
 /* extern declarations for test funcs */
 #define DEFINE_TEST(name)				\
 	extern void test_##name(void) __weak;		\
@@ -1720,7 +1657,7 @@ int main(int argc, char **argv)
 	env.stderr = stderr;
 
 	env.has_testmod = true;
-	if (!env.list_test_names && load_bpf_testmod()) {
+	if (!env.list_test_names && load_bpf_testmod(verbose())) {
 		fprintf(env.stderr, "WARNING! Selftests relying on bpf_testmod.ko will be skipped.\n");
 		env.has_testmod = false;
 	}
@@ -1819,7 +1756,7 @@ int main(int argc, char **argv)
 	close(env.saved_netns_fd);
 out:
 	if (!env.list_test_names && env.has_testmod)
-		unload_bpf_testmod();
+		unload_bpf_testmod(verbose());
 
 	free_test_selector(&env.test_selector);
 	free_test_selector(&env.subtest_selector);

tools/testing/selftests/bpf/test_progs.h

@@ -405,7 +405,6 @@ static inline void *u64_to_ptr(__u64 ptr)
 int bpf_find_map(const char *test, struct bpf_object *obj, const char *name);
 int compare_map_keys(int map1_fd, int map2_fd);
 int compare_stack_ips(int smap_fd, int amap_fd, int stack_trace_len);
-int kern_sync_rcu(void);
 int trigger_module_test_read(int read_sz);
 int trigger_module_test_write(int write_sz);
 int write_sysctl(const char *sysctl, const char *value);

tools/testing/selftests/bpf/testing_helpers.c

@@ -9,6 +9,7 @@
 #include <bpf/libbpf.h>
 #include "test_progs.h"
 #include "testing_helpers.h"
+#include <linux/membarrier.h>
 
 int parse_num_list(const char *s, bool **num_set, int *num_set_len)
 {
@@ -326,3 +327,65 @@ __u64 read_perf_max_sample_freq(void)
 	fclose(f);
 	return sample_freq;
 }
+
+static int finit_module(int fd, const char *param_values, int flags)
+{
+	return syscall(__NR_finit_module, fd, param_values, flags);
+}
+
+static int delete_module(const char *name, int flags)
+{
+	return syscall(__NR_delete_module, name, flags);
+}
+
+void unload_bpf_testmod(bool verbose)
+{
+	if (kern_sync_rcu())
+		fprintf(stderr, "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;
+		}
+		fprintf(stderr, "Failed to unload bpf_testmod.ko from kernel: %d\n", -errno);
+		return;
+	}
+	if (verbose)
+		fprintf(stdout, "Successfully unloaded bpf_testmod.ko.\n");
+}
+
+int load_bpf_testmod(bool verbose)
+{
+	int fd;
+
+	/* ensure previous instance of the module is unloaded */
+	unload_bpf_testmod(verbose);
+
+	if (verbose)
+		fprintf(stdout, "Loading bpf_testmod.ko...\n");
+
+	fd = open("bpf_testmod.ko", O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr, "Can't find bpf_testmod.ko kernel module: %d\n", -errno);
+		return -ENOENT;
+	}
+	if (finit_module(fd, "", 0)) {
+		fprintf(stderr, "Failed to load bpf_testmod.ko into the kernel: %d\n", -errno);
+		close(fd);
+		return -EINVAL;
+	}
+	close(fd);
+
+	if (verbose)
+		fprintf(stdout, "Successfully loaded bpf_testmod.ko.\n");
+	return 0;
+}
+
+/*
+ * Trigger synchronize_rcu() in kernel.
+ */
+int kern_sync_rcu(void)
+{
+	return syscall(__NR_membarrier, MEMBARRIER_CMD_SHARED, 0, 0);
+}

tools/testing/selftests/bpf/testing_helpers.h

 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
 /* Copyright (C) 2020 Facebook, Inc. */
+
+#ifndef __TESTING_HELPERS_H
+#define __TESTING_HELPERS_H
+
 #include <stdbool.h>
 #include <bpf/bpf.h>
 #include <bpf/libbpf.h>
@@ -25,3 +29,8 @@ int parse_test_list_file(const char *path,
 			 bool is_glob_pattern);
 
 __u64 read_perf_max_sample_freq(void);
+int load_bpf_testmod(bool verbose);
+void unload_bpf_testmod(bool verbose);
+int kern_sync_rcu(void);
+
+#endif /* __TESTING_HELPERS_H */