selftests/bpf: Add test to access integer type of variable array

Add prog test for accessing integer type of variable array in tracing
program.
In addition, hook load_balance function to access sd->span[0], only
to confirm whether the load is successful. Because there is no direct
way to trigger load_balance call.

Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
Link: https://lore.kernel.org/r/20230420032735.27760-3-zhoufeng.zf@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index fe847eb..52785ba 100644 (file)
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -28,6 +28,11 @@ struct bpf_testmod_struct_arg_2 {
        long b;
 };
 
+struct bpf_testmod_struct_arg_3 {
+       int a;
+       int b[];
+};
+
 __diag_push();
 __diag_ignore_all("-Wmissing-prototypes",
                  "Global functions as their definitions will be in bpf_testmod.ko BTF");
@@ -63,6 +68,12 @@ bpf_testmod_test_struct_arg_5(void) {
        return bpf_testmod_test_struct_arg_result;
 }
 
+noinline int
+bpf_testmod_test_struct_arg_6(struct bpf_testmod_struct_arg_3 *a) {
+       bpf_testmod_test_struct_arg_result = a->b[0];
+       return bpf_testmod_test_struct_arg_result;
+}
+
 __bpf_kfunc void
 bpf_testmod_test_mod_kfunc(int i)
 {
@@ -195,6 +206,7 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj,
        };
        struct bpf_testmod_struct_arg_1 struct_arg1 = {10};
        struct bpf_testmod_struct_arg_2 struct_arg2 = {2, 3};
+       struct bpf_testmod_struct_arg_3 *struct_arg3;
        int i = 1;
 
        while (bpf_testmod_return_ptr(i))
@@ -206,6 +218,14 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj,
        (void)bpf_testmod_test_struct_arg_4(struct_arg1, 1, 2, 3, struct_arg2);
        (void)bpf_testmod_test_struct_arg_5();
 
+       struct_arg3 = kmalloc((sizeof(struct bpf_testmod_struct_arg_3) +
+                               sizeof(int)), GFP_KERNEL);
+       if (struct_arg3 != NULL) {
+               struct_arg3->b[0] = 1;
+               (void)bpf_testmod_test_struct_arg_6(struct_arg3);
+               kfree(struct_arg3);
+       }
+
        /* This is always true. Use the check to make sure the compiler
         * doesn't remove bpf_testmod_loop_test.
         */

diff --git a/tools/testing/selftests/bpf/prog_tests/access_variable_array.c b/tools/testing/selftests/bpf/prog_tests/access_variable_array.c
new file mode 100644 (file)
index 0000000..0813178
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/access_variable_array.c
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Bytedance */
+
+#include <test_progs.h>
+#include "test_access_variable_array.skel.h"
+
+void test_access_variable_array(void)
+{
+       struct test_access_variable_array *skel;
+
+       skel = test_access_variable_array__open_and_load();
+       if (!ASSERT_OK_PTR(skel, "test_access_variable_array__open_and_load"))
+               return;
+
+       test_access_variable_array__destroy(skel);
+}

diff --git a/tools/testing/selftests/bpf/prog_tests/tracing_struct.c b/tools/testing/selftests/bpf/prog_tests/tracing_struct.c
index 48dc947..1c75a32 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/tracing_struct.c
+++ b/tools/testing/selftests/bpf/prog_tests/tracing_struct.c
@@ -53,6 +53,8 @@ static void test_fentry(void)
 
        ASSERT_EQ(skel->bss->t5_ret, 1, "t5 ret");
 
+       ASSERT_EQ(skel->bss->t6, 1, "t6 ret");
+
        tracing_struct__detach(skel);
 destroy_skel:
        tracing_struct__destroy(skel);

diff --git a/tools/testing/selftests/bpf/progs/test_access_variable_array.c b/tools/testing/selftests/bpf/progs/test_access_variable_array.c
new file mode 100644 (file)
index 0000000..808c49b
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_access_variable_array.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Bytedance */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+unsigned long span = 0;
+
+SEC("fentry/load_balance")
+int BPF_PROG(fentry_fentry, int this_cpu, struct rq *this_rq,
+               struct sched_domain *sd)
+{
+       span = sd->span[0];
+
+       return 0;
+}
+
+char _license[] SEC("license") = "GPL";

diff --git a/tools/testing/selftests/bpf/progs/tracing_struct.c b/tools/testing/selftests/bpf/progs/tracing_struct.c
index e718f0e..c435a3a 100644 (file)
--- a/tools/testing/selftests/bpf/progs/tracing_struct.c
+++ b/tools/testing/selftests/bpf/progs/tracing_struct.c
@@ -13,12 +13,18 @@ struct bpf_testmod_struct_arg_2 {
        long b;
 };
 
+struct bpf_testmod_struct_arg_3 {
+       int a;
+       int b[];
+};
+
 long t1_a_a, t1_a_b, t1_b, t1_c, t1_ret, t1_nregs;
 __u64 t1_reg0, t1_reg1, t1_reg2, t1_reg3;
 long t2_a, t2_b_a, t2_b_b, t2_c, t2_ret;
 long t3_a, t3_b, t3_c_a, t3_c_b, t3_ret;
 long t4_a_a, t4_b, t4_c, t4_d, t4_e_a, t4_e_b, t4_ret;
 long t5_ret;
+int t6;
 
 SEC("fentry/bpf_testmod_test_struct_arg_1")
 int BPF_PROG2(test_struct_arg_1, struct bpf_testmod_struct_arg_2, a, int, b, int, c)
@@ -117,4 +123,11 @@ int BPF_PROG2(test_struct_arg_10, int, ret)
        return 0;
 }
 
+SEC("fentry/bpf_testmod_test_struct_arg_6")
+int BPF_PROG2(test_struct_arg_11, struct bpf_testmod_struct_arg_3 *, a)
+{
+       t6 = a->b[0];
+       return 0;
+}
+
 char _license[] SEC("license") = "GPL";