[RFC,bpf-next,6/6] selftests/bpf: Add test cases for demonstrating runtime acquire/release reference tracking

Commit Message

Juntong Deng Feb. 14, 2025, 12:26 a.m. UTC

This patch adds test cases for demonstrating runtime acquire/release
reference tracking.

Test cases include simple, branch, and loop.

Simple test case has no branches or loops.

Branch test case contains if statements.

Loop test case contains the bpf_iter_num iterator.

Signed-off-by: Juntong Deng <[e-mail]>
---
 tools/testing/selftests/runtime/Makefile     | 20 ++++++++++
 tools/testing/selftests/runtime/branch.bpf.c | 42 ++++++++++++++++++++
 tools/testing/selftests/runtime/branch.c     | 19 +++++++++
 tools/testing/selftests/runtime/loop.bpf.c   | 37 +++++++++++++++++
 tools/testing/selftests/runtime/loop.c       | 19 +++++++++
 tools/testing/selftests/runtime/simple.bpf.c | 35 ++++++++++++++++
 tools/testing/selftests/runtime/simple.c     | 19 +++++++++
 7 files changed, 191 insertions(+)
 create mode 100644 tools/testing/selftests/runtime/Makefile
 create mode 100644 tools/testing/selftests/runtime/branch.bpf.c
 create mode 100644 tools/testing/selftests/runtime/branch.c
 create mode 100644 tools/testing/selftests/runtime/loop.bpf.c
 create mode 100644 tools/testing/selftests/runtime/loop.c
 create mode 100644 tools/testing/selftests/runtime/simple.bpf.c
 create mode 100644 tools/testing/selftests/runtime/simple.c

Patch

diff --git a/tools/testing/selftests/runtime/Makefile b/tools/testing/selftests/runtime/Makefile
new file mode 100644
index 000000000000..d03133786a26
--- /dev/null
+++ b/tools/testing/selftests/runtime/Makefile
@@ -0,0 +1,20 @@ 
+targets = simple branch loop
+
+all: $(targets)
+
+vmlinux.h:
+	bpftool btf dump file /sys/kernel/btf/vmlinux format c > vmlinux.h
+
+%.bpf.o: %.bpf.c vmlinux.h
+	clang -O2 -g -target bpf -c $*.bpf.c -o $*.bpf.o
+
+%.skel.h: %.bpf.o
+	bpftool gen skeleton $*.bpf.o > $*.skel.h
+
+$(targets): %: %.c %.skel.h
+	clang $< -lelf -lbpf -o $@
+
+clean:
+	rm -f *.o *.skel.h vmlinux.h $(targets)
+
+.SECONDARY:
diff --git a/tools/testing/selftests/runtime/branch.bpf.c b/tools/testing/selftests/runtime/branch.bpf.c
new file mode 100644
index 000000000000..87697151299c
--- /dev/null
+++ b/tools/testing/selftests/runtime/branch.bpf.c
@@ -0,0 +1,42 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+char LICENSE[] SEC("license") = "GPL";
+
+void bpf_task_release(struct task_struct *p) __ksym;
+struct task_struct *bpf_task_from_pid(s32 pid) __ksym;
+
+int test = 5;
+
+SEC("syscall")
+int test_branch(void *arg)
+{
+	struct task_struct *task1;
+
+	task1 = bpf_task_from_pid(1);
+
+	if (test > 2) {
+		struct task_struct *task2;
+
+		task2 = bpf_task_from_pid(2);
+		if (task2)
+			bpf_task_release(task2);
+	}
+
+	if (test < 2) {
+		struct task_struct *task3;
+
+		task3 = bpf_task_from_pid(3);
+		if (task3)
+			bpf_task_release(task3);
+	}
+
+	if (task1)
+		bpf_task_release(task1);
+
+	return 0;
+}
diff --git a/tools/testing/selftests/runtime/branch.c b/tools/testing/selftests/runtime/branch.c
new file mode 100644
index 000000000000..3592e14f1f75
--- /dev/null
+++ b/tools/testing/selftests/runtime/branch.c
@@ -0,0 +1,19 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include "branch.skel.h"
+
+int main(int argc, char **argv)
+{
+	struct branch_bpf *skel;
+	int err, prog_fd;
+
+	skel = branch_bpf__open_and_load();
+	prog_fd = bpf_program__fd(skel->progs.test_branch);
+	err = bpf_prog_test_run_opts(prog_fd, NULL);
+
+	branch_bpf__destroy(skel);
+	return err;
+}
diff --git a/tools/testing/selftests/runtime/loop.bpf.c b/tools/testing/selftests/runtime/loop.bpf.c
new file mode 100644
index 000000000000..2b49ec9e1058
--- /dev/null
+++ b/tools/testing/selftests/runtime/loop.bpf.c
@@ -0,0 +1,37 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+char LICENSE[] SEC("license") = "GPL";
+
+void bpf_task_release(struct task_struct *p) __ksym;
+struct task_struct *bpf_task_from_pid(s32 pid) __ksym;
+
+SEC("syscall")
+int test_loop(void *arg)
+{
+	struct task_struct *task_loop;
+	struct task_struct *task1;
+	int *v;
+
+	task1 = bpf_task_from_pid(1);
+
+	struct bpf_iter_num it;
+
+	bpf_iter_num_new(&it, 1, 3);
+	while ((v = bpf_iter_num_next(&it))) {
+		task_loop = bpf_task_from_pid(*v);
+		if (task_loop)
+			bpf_task_release(task_loop);
+	}
+
+	bpf_iter_num_destroy(&it);
+
+	if (task1)
+		bpf_task_release(task1);
+
+	return 0;
+}
diff --git a/tools/testing/selftests/runtime/loop.c b/tools/testing/selftests/runtime/loop.c
new file mode 100644
index 000000000000..bde83e5595e4
--- /dev/null
+++ b/tools/testing/selftests/runtime/loop.c
@@ -0,0 +1,19 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include "loop.skel.h"
+
+int main(int argc, char **argv)
+{
+	struct loop_bpf *skel;
+	int err, prog_fd;
+
+	skel = loop_bpf__open_and_load();
+	prog_fd = bpf_program__fd(skel->progs.test_loop);
+	err = bpf_prog_test_run_opts(prog_fd, NULL);
+
+	loop_bpf__destroy(skel);
+	return err;
+}
diff --git a/tools/testing/selftests/runtime/simple.bpf.c b/tools/testing/selftests/runtime/simple.bpf.c
new file mode 100644
index 000000000000..ad7989ebb7d4
--- /dev/null
+++ b/tools/testing/selftests/runtime/simple.bpf.c
@@ -0,0 +1,35 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+char LICENSE[] SEC("license") = "GPL";
+
+void bpf_task_release(struct task_struct *p) __ksym;
+struct task_struct *bpf_task_from_pid(s32 pid) __ksym;
+
+struct bpf_cpumask *bpf_cpumask_create(void) __ksym;
+void bpf_cpumask_release(struct bpf_cpumask *cpumask) __ksym;
+
+SEC("syscall")
+int test_simple(void *arg)
+{
+	struct task_struct *task;
+	struct bpf_cpumask *cpumask;
+
+	task = bpf_task_from_pid(1);
+	if (!task)
+		return 0;
+
+	cpumask = bpf_cpumask_create();
+	if (!cpumask)
+		goto error_cpumask;
+
+	bpf_cpumask_release(cpumask);
+error_cpumask:
+	bpf_task_release(task);
+
+	return 0;
+}
diff --git a/tools/testing/selftests/runtime/simple.c b/tools/testing/selftests/runtime/simple.c
new file mode 100644
index 000000000000..e65959aac89b
--- /dev/null
+++ b/tools/testing/selftests/runtime/simple.c
@@ -0,0 +1,19 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include "simple.skel.h"
+
+int main(int argc, char **argv)
+{
+	struct simple_bpf *skel;
+	int err, prog_fd;
+
+	skel = simple_bpf__open_and_load();
+	prog_fd = bpf_program__fd(skel->progs.test_simple);
+	err = bpf_prog_test_run_opts(prog_fd, NULL);
+
+	simple_bpf__destroy(skel);
+	return err;
+}