[bpf-next,v5,9/9] selftests/bpf: Add struct_ops prog private stack tests

Commit Message

Yonghong Song Oct. 17, 2024, 10:32 p.m. UTC

Add two tests for struct_ops using private stack. One is with nested
two different callback functions and the other is the same callback
function recursing itself. For the second case, at run time, the
jit trampoline recursion check kicks in to prevent the recursion.

Signed-off-by: Yonghong Song <[e-mail]>
---
 .../selftests/bpf/bpf_testmod/bpf_testmod.c   | 83 +++++++++++++++++++
 .../selftests/bpf/bpf_testmod/bpf_testmod.h   |  6 ++
 .../bpf/prog_tests/struct_ops_private_stack.c | 80 ++++++++++++++++++
 .../bpf/progs/struct_ops_private_stack.c      | 62 ++++++++++++++
 .../progs/struct_ops_private_stack_recur.c    | 50 +++++++++++
 5 files changed, 281 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/struct_ops_private_stack.c
 create mode 100644 tools/testing/selftests/bpf/progs/struct_ops_private_stack.c
 create mode 100644 tools/testing/selftests/bpf/progs/struct_ops_private_stack_recur.c

Patch

diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index 8835761d9a12..aa61aaa847a2 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -245,6 +245,39 @@  __bpf_kfunc void bpf_testmod_ctx_release(struct bpf_testmod_ctx *ctx)
 		call_rcu(&ctx->rcu, testmod_free_cb);
 }
 
+static struct bpf_testmod_ops3 *st_ops3;
+
+static int bpf_testmod_test_3(void)
+{
+	return 0;
+}
+
+static int bpf_testmod_test_4(void)
+{
+	return 0;
+}
+
+static struct bpf_testmod_ops3 __bpf_testmod_ops3 = {
+	.test_1 = bpf_testmod_test_3,
+	.test_2 = bpf_testmod_test_4,
+};
+
+static void bpf_testmod_test_struct_ops3(void)
+{
+	if (st_ops3)
+		st_ops3->test_1();
+}
+
+__bpf_kfunc void bpf_testmod_ops3_call_test_1(void)
+{
+	st_ops3->test_1();
+}
+
+__bpf_kfunc void bpf_testmod_ops3_call_test_2(void)
+{
+	st_ops3->test_2();
+}
+
 struct bpf_testmod_btf_type_tag_1 {
 	int a;
 };
@@ -380,6 +413,8 @@  bpf_testmod_test_read(struct file *file, struct kobject *kobj,
 
 	(void)bpf_testmod_test_arg_ptr_to_struct(&struct_arg1_2);
 
+	bpf_testmod_test_struct_ops3();
+
 	struct_arg3 = kmalloc((sizeof(struct bpf_testmod_struct_arg_3) +
 				sizeof(int)), GFP_KERNEL);
 	if (struct_arg3 != NULL) {
@@ -584,6 +619,8 @@  BTF_ID_FLAGS(func, bpf_kfunc_trusted_num_test, KF_TRUSTED_ARGS)
 BTF_ID_FLAGS(func, bpf_kfunc_rcu_task_test, KF_RCU)
 BTF_ID_FLAGS(func, bpf_testmod_ctx_create, KF_ACQUIRE | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_testmod_ctx_release, KF_RELEASE)
+BTF_ID_FLAGS(func, bpf_testmod_ops3_call_test_1)
+BTF_ID_FLAGS(func, bpf_testmod_ops3_call_test_2)
 BTF_KFUNCS_END(bpf_testmod_common_kfunc_ids)
 
 BTF_ID_LIST(bpf_testmod_dtor_ids)
@@ -1094,6 +1131,16 @@  static const struct bpf_verifier_ops bpf_testmod_verifier_ops = {
 	.is_valid_access = bpf_testmod_ops_is_valid_access,
 };
 
+static bool bpf_testmod_ops3_priv_stack_allowed(void)
+{
+	return true;
+}
+
+static const struct bpf_verifier_ops bpf_testmod_verifier_ops3 = {
+	.is_valid_access = bpf_testmod_ops_is_valid_access,
+	.priv_stack_allowed = bpf_testmod_ops3_priv_stack_allowed,
+};
+
 static int bpf_dummy_reg(void *kdata, struct bpf_link *link)
 {
 	struct bpf_testmod_ops *ops = kdata;
@@ -1173,6 +1220,41 @@  struct bpf_struct_ops bpf_testmod_ops2 = {
 	.owner = THIS_MODULE,
 };
 
+static int st_ops3_reg(void *kdata, struct bpf_link *link)
+{
+	int err = 0;
+
+	mutex_lock(&st_ops_mutex);
+	if (st_ops3) {
+		pr_err("st_ops has already been registered\n");
+		err = -EEXIST;
+		goto unlock;
+	}
+	st_ops3 = kdata;
+
+unlock:
+	mutex_unlock(&st_ops_mutex);
+	return err;
+}
+
+static void st_ops3_unreg(void *kdata, struct bpf_link *link)
+{
+	mutex_lock(&st_ops_mutex);
+	st_ops3 = NULL;
+	mutex_unlock(&st_ops_mutex);
+}
+
+struct bpf_struct_ops bpf_testmod_ops3 = {
+	.verifier_ops = &bpf_testmod_verifier_ops3,
+	.init = bpf_testmod_ops_init,
+	.init_member = bpf_testmod_ops_init_member,
+	.reg = st_ops3_reg,
+	.unreg = st_ops3_unreg,
+	.cfi_stubs = &__bpf_testmod_ops3,
+	.name = "bpf_testmod_ops3",
+	.owner = THIS_MODULE,
+};
+
 static int bpf_test_mod_st_ops__test_prologue(struct st_ops_args *args)
 {
 	return 0;
@@ -1331,6 +1413,7 @@  static int bpf_testmod_init(void)
 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &bpf_testmod_kfunc_set);
 	ret = ret ?: register_bpf_struct_ops(&bpf_bpf_testmod_ops, bpf_testmod_ops);
 	ret = ret ?: register_bpf_struct_ops(&bpf_testmod_ops2, bpf_testmod_ops2);
+	ret = ret ?: register_bpf_struct_ops(&bpf_testmod_ops3, bpf_testmod_ops3);
 	ret = ret ?: register_bpf_struct_ops(&testmod_st_ops, bpf_testmod_st_ops);
 	ret = ret ?: register_btf_id_dtor_kfuncs(bpf_testmod_dtors,
 						 ARRAY_SIZE(bpf_testmod_dtors),
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
index fb7dff47597a..59c600074eea 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
@@ -92,6 +92,12 @@  struct bpf_testmod_ops {
 
 struct bpf_testmod_ops2 {
 	int (*test_1)(void);
+	int (*test_2)(void);
+};
+
+struct bpf_testmod_ops3 {
+	int (*test_1)(void);
+	int (*test_2)(void);
 };
 
 struct st_ops_args {
diff --git a/tools/testing/selftests/bpf/prog_tests/struct_ops_private_stack.c b/tools/testing/selftests/bpf/prog_tests/struct_ops_private_stack.c
new file mode 100644
index 000000000000..16ea92eea2cf
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/struct_ops_private_stack.c
@@ -0,0 +1,80 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include <test_progs.h>
+#include "struct_ops_private_stack.skel.h"
+#include "struct_ops_private_stack_recur.skel.h"
+
+static void test_private_stack(void)
+{
+	struct struct_ops_private_stack *skel;
+	struct bpf_link *link;
+	int err;
+
+	skel = struct_ops_private_stack__open();
+	if (!ASSERT_OK_PTR(skel, "struct_ops_private_stack__open"))
+		return;
+
+	if (skel->data->skip) {
+		test__skip();
+		goto cleanup;
+	}
+
+	err = struct_ops_private_stack__load(skel);
+	if (!ASSERT_OK(err, "struct_ops_private_stack__load"))
+		goto cleanup;
+
+	link = bpf_map__attach_struct_ops(skel->maps.testmod_1);
+	if (!ASSERT_OK_PTR(link, "attach_struct_ops"))
+		goto cleanup;
+
+	ASSERT_OK(trigger_module_test_read(256), "trigger_read");
+
+	ASSERT_EQ(skel->bss->val_i, 3, "val_i");
+	ASSERT_EQ(skel->bss->val_j, 8, "val_j");
+
+	bpf_link__destroy(link);
+
+cleanup:
+	struct_ops_private_stack__destroy(skel);
+}
+
+static void test_private_stack_recur(void)
+{
+	struct struct_ops_private_stack_recur *skel;
+	struct bpf_link *link;
+	int err;
+
+	skel = struct_ops_private_stack_recur__open();
+	if (!ASSERT_OK_PTR(skel, "struct_ops_private_stack_recur__open"))
+		return;
+
+	if (skel->data->skip) {
+		test__skip();
+		goto cleanup;
+	}
+
+	err = struct_ops_private_stack_recur__load(skel);
+	if (!ASSERT_OK(err, "struct_ops_private_stack_recur__load"))
+		goto cleanup;
+
+	link = bpf_map__attach_struct_ops(skel->maps.testmod_1);
+	if (!ASSERT_OK_PTR(link, "attach_struct_ops"))
+		goto cleanup;
+
+	ASSERT_OK(trigger_module_test_read(256), "trigger_read");
+
+	ASSERT_EQ(skel->bss->val_j, 3, "val_j");
+
+	bpf_link__destroy(link);
+
+cleanup:
+	struct_ops_private_stack_recur__destroy(skel);
+}
+
+void test_struct_ops_private_stack(void)
+{
+	if (test__start_subtest("private_stack"))
+		test_private_stack();
+	if (test__start_subtest("private_stack_recur"))
+		test_private_stack_recur();
+}
diff --git a/tools/testing/selftests/bpf/progs/struct_ops_private_stack.c b/tools/testing/selftests/bpf/progs/struct_ops_private_stack.c
new file mode 100644
index 000000000000..921974263587
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/struct_ops_private_stack.c
@@ -0,0 +1,62 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include <vmlinux.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include "../bpf_testmod/bpf_testmod.h"
+
+char _license[] SEC("license") = "GPL";
+
+#if defined(__TARGET_ARCH_x86)
+bool skip __attribute((__section__(".data"))) = false;
+#else
+bool skip = true;
+#endif
+
+void bpf_testmod_ops3_call_test_2(void) __ksym;
+
+int val_i, val_j;
+
+__noinline static int subprog2(int *a, int *b)
+{
+	return val_i + a[10] + b[20];
+}
+
+__noinline static int subprog1(int *a)
+{
+	/* stack size 400 bytes */
+	volatile int b[100] = {};
+
+	b[20] = 2;
+	return subprog2(a, (int *)b);
+}
+
+
+SEC("struct_ops")
+int BPF_PROG(test_1)
+{
+	/* stack size 400 bytes */
+	volatile int a[100] = {};
+
+	a[10] = 1;
+	val_i = subprog1((int *)a);
+	bpf_testmod_ops3_call_test_2();
+	return 0;
+}
+
+SEC("struct_ops")
+int BPF_PROG(test_2)
+{
+	/* stack size 400 bytes */
+	volatile int a[100] = {};
+
+	a[10] = 3;
+	val_j = subprog1((int *)a);
+	return 0;
+}
+
+SEC(".struct_ops")
+struct bpf_testmod_ops3 testmod_1 = {
+	.test_1 = (void *)test_1,
+	.test_2 = (void *)test_2,
+};
diff --git a/tools/testing/selftests/bpf/progs/struct_ops_private_stack_recur.c b/tools/testing/selftests/bpf/progs/struct_ops_private_stack_recur.c
new file mode 100644
index 000000000000..c593059cea3c
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/struct_ops_private_stack_recur.c
@@ -0,0 +1,50 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include <vmlinux.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include "../bpf_testmod/bpf_testmod.h"
+
+char _license[] SEC("license") = "GPL";
+
+#if defined(__TARGET_ARCH_x86)
+bool skip __attribute((__section__(".data"))) = false;
+#else
+bool skip = true;
+#endif
+
+void bpf_testmod_ops3_call_test_1(void) __ksym;
+
+int val_i, val_j;
+
+__noinline static int subprog2(int *a, int *b)
+{
+	return val_i + a[10] + b[20];
+}
+
+__noinline static int subprog1(int *a)
+{
+	/* stack size 400 bytes */
+	volatile int b[100] = {};
+
+	b[20] = 2;
+	return subprog2(a, (int *)b);
+}
+
+
+SEC("struct_ops")
+int BPF_PROG(test_1)
+{
+	/* stack size 400 bytes */
+	volatile int a[100] = {};
+
+	a[10] = 1;
+	val_j += subprog1((int *)a);
+	bpf_testmod_ops3_call_test_1();
+	return 0;
+}
+
+SEC(".struct_ops")
+struct bpf_testmod_ops3 testmod_1 = {
+	.test_1 = (void *)test_1,
+};