[RFC PATCH 13/13] perf tests: Add UBPF test case

[Wang Nan <wangnan0@huawei.com>]

Introduce a BPF script use UBPF, test compiling, helper and hook.
Validate passing information through helper and hooks.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
---
 tools/perf/tests/Build                  |  8 ++++
 tools/perf/tests/bpf-script-test-ubpf.c | 68 +++++++++++++++++++++++++++++
 tools/perf/tests/bpf.c                  | 77 ++++++++++++++++++++++++++++++++-
 tools/perf/tests/llvm.c                 |  4 ++
 tools/perf/tests/llvm.h                 |  2 +
 5 files changed, 157 insertions(+), 2 deletions(-)
 create mode 100644 tools/perf/tests/bpf-script-test-ubpf.c

diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build
index 449fe97..0050ff8 100644
--- a/tools/perf/tests/Build
+++ b/tools/perf/tests/Build
@@ -32,6 +32,7 @@ perf-y += parse-no-sample-id-all.o
 perf-y += kmod-path.o
 perf-y += thread-map.o
 perf-y += llvm.o llvm-src-base.o llvm-src-kbuild.o llvm-src-prologue.o llvm-src-relocation.o
+perf-y += llvm-src-ubpf.o
 perf-y += bpf.o
 perf-y += topology.o
 perf-y += cpumap.o
@@ -67,6 +68,13 @@ $(OUTPUT)tests/llvm-src-relocation.c: tests/bpf-script-test-relocation.c tests/B
 	$(Q)sed -e 's/"/\\"/g' -e 's/\(.*\)/"\1\\n"/g' $< >> $@
 	$(Q)echo ';' >> $@
 
+$(OUTPUT)tests/llvm-src-ubpf.c: tests/bpf-script-test-ubpf.c tests/Build
+	$(call rule_mkdir)
+	$(Q)echo '#include <tests/llvm.h>' > $@
+	$(Q)echo 'const char test_llvm__bpf_test_ubpf[] =' >> $@
+	$(Q)sed -e 's/"/\\"/g' -e 's/\(.*\)/"\1\\n"/g' $< >> $@
+	$(Q)echo ';' >> $@
+
 ifeq ($(ARCH),$(filter $(ARCH),x86 arm arm64))
 perf-$(CONFIG_DWARF_UNWIND) += dwarf-unwind.o
 endif
diff --git a/tools/perf/tests/bpf-script-test-ubpf.c b/tools/perf/tests/bpf-script-test-ubpf.c
new file mode 100644
index 0000000..67000d5
--- /dev/null
+++ b/tools/perf/tests/bpf-script-test-ubpf.c
@@ -0,0 +1,68 @@
+/*
+ * bpf-script-test-ubpf.c
+ * Test user space BPF
+ */
+
+#ifndef LINUX_VERSION_CODE
+# error Need LINUX_VERSION_CODE
+# error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig'
+#endif
+#define BPF_ANY 0
+#define BPF_MAP_TYPE_ARRAY 2
+#define BPF_FUNC_map_lookup_elem 1
+#define BPF_FUNC_map_update_elem 2
+
+static void *(*bpf_map_lookup_elem)(void *map, void *key) =
+	(void *) BPF_FUNC_map_lookup_elem;
+static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) =
+	(void *) BPF_FUNC_map_update_elem;
+
+struct bpf_map_def {
+	unsigned int type;
+	unsigned int key_size;
+	unsigned int value_size;
+	unsigned int max_entries;
+};
+
+#define SEC(NAME) __attribute__((section(NAME), used))
+struct bpf_map_def SEC("maps") counter = {
+	.type = BPF_MAP_TYPE_ARRAY,
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.max_entries = 1,
+};
+
+SEC("func=sys_epoll_pwait")
+int bpf_func__sys_epoll_pwait(void *ctx)
+{
+	int ind = 0;
+	int *flag = bpf_map_lookup_elem(&counter, &ind);
+	if (!flag)
+		return 0;
+	__sync_fetch_and_add(flag, 1);
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
+int _version SEC("version") = LINUX_VERSION_CODE;
+
+static void (*ubpf_map_lookup_elem)(struct bpf_map_def *, void *, void *) = (void *)2;
+static void (*ubpf_map_update_elem)(struct bpf_map_def *, void *, void *) = (void *)3;
+static void (*ubpf_test_report)(int) = (void *)63;
+SEC("UBPF;perf_record_start")
+int perf_record_start(void)
+{
+	int idx = 0, val = 1000;
+
+	ubpf_map_update_elem(&counter, &idx, &val);
+	return 0;
+}
+
+SEC("UBPF;perf_record_end")
+int perf_record_end(int *x)
+{
+	int idx = 0, val;
+
+	ubpf_map_lookup_elem(&counter, &idx, &val);
+	ubpf_test_report(val + *x);
+	return 0;
+}
diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c
index f31eed3..2841718 100644
--- a/tools/perf/tests/bpf.c
+++ b/tools/perf/tests/bpf.c
@@ -5,10 +5,13 @@
 #include <util/evlist.h>
 #include <linux/bpf.h>
 #include <linux/filter.h>
+#include <bpf/libbpf.h>
 #include <bpf/bpf.h>
 #include "tests.h"
 #include "llvm.h"
 #include "debug.h"
+#include "ubpf-helpers.h"
+#include "ubpf-hooks.h"
 #define NR_ITERS       111
 
 #ifdef HAVE_LIBBPF_SUPPORT
@@ -46,6 +49,34 @@ static int llseek_loop(void)
 
 #endif
 
+union testcase_context {
+	void *ptr;
+	unsigned long num;
+};
+
+#ifdef HAVE_UBPF_SUPPORT
+static int __ubpf_report_val;
+
+static void test_report(int val)
+{
+	__ubpf_report_val = val;
+}
+
+static int ubpf_prepare(union testcase_context *ctx __maybe_unused)
+{
+	ubpf_hook_perf_record_start(0);
+	return 0;
+}
+
+static int ubpf_verify(union testcase_context *ctx __maybe_unused)
+{
+	ubpf_hook_perf_record_end(0, 1234);
+	if (__ubpf_report_val != 2345)
+		return TEST_FAIL;
+	return TEST_OK;
+}
+#endif
+
 static struct {
 	enum test_llvm__testcase prog_id;
 	const char *desc;
@@ -54,6 +85,10 @@ static struct {
 	const char *msg_load_fail;
 	int (*target_func)(void);
 	int expect_result;
+
+	union testcase_context context;
+	int (*prepare)(union testcase_context *);
+	int (*verify)(union testcase_context *);
 } bpf_testcase_table[] = {
 	{
 		LLVM_TESTCASE_BASE,
@@ -63,6 +98,7 @@ static struct {
 		"load bpf object failed",
 		&epoll_pwait_loop,
 		(NR_ITERS + 1) / 2,
+		{0}, NULL, NULL
 	},
 #ifdef HAVE_BPF_PROLOGUE
 	{
@@ -73,6 +109,7 @@ static struct {
 		"check your vmlinux setting?",
 		&llseek_loop,
 		(NR_ITERS + 1) / 4,
+		{0}, NULL, NULL
 	},
 #endif
 	{
@@ -83,11 +120,27 @@ static struct {
 		"libbpf error when dealing with relocation",
 		NULL,
 		0,
+		{0}, NULL, NULL
 	},
+#ifdef HAVE_UBPF_SUPPORT
+	{
+		LLVM_TESTCASE_BPF_UBPF,
+		"Test UBPF support",
+		"[bpf_ubpf_test]",
+		"fix 'perf test LLVM' first",
+		"failed to load UBPF",
+		&epoll_pwait_loop,
+		0,
+		{0}, ubpf_prepare, ubpf_verify,
+	}
+#endif
 };
 
 static int do_test(struct bpf_object *obj, int (*func)(void),
-		   int expect)
+		   int expect,
+		   int (*prepare)(union testcase_context *),
+		   int (*verify)(union testcase_context *),
+		   union testcase_context *ctx)
 {
 	struct record_opts opts = {
 		.target = {
@@ -154,6 +207,14 @@ static int do_test(struct bpf_object *obj, int (*func)(void),
 		goto out_delete_evlist;
 	}
 
+	if (prepare) {
+		err = prepare(ctx);
+		if (err < 0) {
+			pr_debug("prepare fail\n");
+			goto out_delete_evlist;
+		}
+	}
+
 	perf_evlist__enable(evlist);
 	(*func)();
 	perf_evlist__disable(evlist);
@@ -176,6 +237,8 @@ static int do_test(struct bpf_object *obj, int (*func)(void),
 
 	ret = TEST_OK;
 
+	if (verify)
+		ret = verify(ctx);
 out_delete_evlist:
 	perf_evlist__delete(evlist);
 	return ret;
@@ -201,6 +264,13 @@ static int __test__bpf(int idx)
 	size_t obj_buf_sz;
 	struct bpf_object *obj;
 
+#ifdef HAVE_UBPF_SUPPORT
+	ret = libbpf_register_ubpf_func(63, "test_report", test_report);
+	if (ret) {
+		pr_debug("Unable to register UBPF helper\n");
+		return TEST_FAIL;
+	}
+#endif
 	ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz,
 				       bpf_testcase_table[idx].prog_id,
 				       true, NULL);
@@ -229,7 +299,10 @@ static int __test__bpf(int idx)
 	if (obj)
 		ret = do_test(obj,
 			      bpf_testcase_table[idx].target_func,
-			      bpf_testcase_table[idx].expect_result);
+			      bpf_testcase_table[idx].expect_result,
+			      bpf_testcase_table[idx].prepare,
+			      bpf_testcase_table[idx].verify,
+			      &bpf_testcase_table[idx].context);
 out:
 	bpf__clear();
 	return ret;
diff --git a/tools/perf/tests/llvm.c b/tools/perf/tests/llvm.c
index cff564f..92b0a42 100644
--- a/tools/perf/tests/llvm.c
+++ b/tools/perf/tests/llvm.c
@@ -48,6 +48,10 @@ static struct {
 		.desc = "Compile source for BPF relocation test",
 		.should_load_fail = true,
 	},
+	[LLVM_TESTCASE_BPF_UBPF] = {
+		.source = test_llvm__bpf_test_ubpf,
+		.desc = "Compile source for UBPF test",
+	},
 };
 
 int
diff --git a/tools/perf/tests/llvm.h b/tools/perf/tests/llvm.h
index 0eaa604..8ae4aae 100644
--- a/tools/perf/tests/llvm.h
+++ b/tools/perf/tests/llvm.h
@@ -8,12 +8,14 @@ extern const char test_llvm__bpf_base_prog[];
 extern const char test_llvm__bpf_test_kbuild_prog[];
 extern const char test_llvm__bpf_test_prologue_prog[];
 extern const char test_llvm__bpf_test_relocation[];
+extern const char test_llvm__bpf_test_ubpf[];
 
 enum test_llvm__testcase {
 	LLVM_TESTCASE_BASE,
 	LLVM_TESTCASE_KBUILD,
 	LLVM_TESTCASE_BPF_PROLOGUE,
 	LLVM_TESTCASE_BPF_RELOCATION,
+	LLVM_TESTCASE_BPF_UBPF,
 	__LLVM_TESTCASE_MAX,
 };
 
-- 
1.8.3.4