1 files changed, 134 insertions, 26 deletions

diff --git a/net/bpf/bpf_dummy_struct_ops.c b/net/bpf/bpf_dummy_struct_ops.c
index 1ac4467928a9..812457819b5a 100644
--- a/net/bpf/bpf_dummy_struct_ops.c
+++ b/net/bpf/bpf_dummy_struct_ops.c
@@ -7,16 +7,23 @@
 #include <linux/bpf.h>
 #include <linux/btf.h>
 
-extern struct bpf_struct_ops bpf_bpf_dummy_ops;
+static struct bpf_struct_ops bpf_bpf_dummy_ops;
 
 /* A common type for test_N with return value in bpf_dummy_ops */
 typedef int (*dummy_ops_test_ret_fn)(struct bpf_dummy_ops_state *state, ...);
 
+static int dummy_ops_test_ret_function(struct bpf_dummy_ops_state *state, ...)
+{
+	return 0;
+}
+
 struct bpf_dummy_ops_test_args {
 	u64 args[MAX_BPF_FUNC_ARGS];
 	struct bpf_dummy_ops_state state;
 };
 
+static struct btf *bpf_dummy_ops_btf;
+
 static struct bpf_dummy_ops_test_args *
 dummy_ops_init_args(const union bpf_attr *kattr, unsigned int nr)
 {
@@ -62,7 +69,7 @@ static int dummy_ops_copy_args(struct bpf_dummy_ops_test_args *args)
 
 static int dummy_ops_call_op(void *image, struct bpf_dummy_ops_test_args *args)
 {
-	dummy_ops_test_ret_fn test = (void *)image;
+	dummy_ops_test_ret_fn test = (void *)image + cfi_get_offset();
 	struct bpf_dummy_ops_state *state = NULL;
 
 	/* state needs to be NULL if args[0] is 0 */
@@ -72,6 +79,51 @@ static int dummy_ops_call_op(void *image, struct bpf_dummy_ops_test_args *args)
 		    args->args[3], args->args[4]);
 }
 
+static const struct bpf_ctx_arg_aux *find_ctx_arg_info(struct bpf_prog_aux *aux, int offset)
+{
+	int i;
+
+	for (i = 0; i < aux->ctx_arg_info_size; i++)
+		if (aux->ctx_arg_info[i].offset == offset)
+			return &aux->ctx_arg_info[i];
+
+	return NULL;
+}
+
+/* There is only one check at the moment:
+ * - zero should not be passed for pointer parameters not marked as nullable.
+ */
+static int check_test_run_args(struct bpf_prog *prog, struct bpf_dummy_ops_test_args *args)
+{
+	const struct btf_type *func_proto = prog->aux->attach_func_proto;
+
+	for (u32 arg_no = 0; arg_no < btf_type_vlen(func_proto) ; ++arg_no) {
+		const struct btf_param *param = &btf_params(func_proto)[arg_no];
+		const struct bpf_ctx_arg_aux *info;
+		const struct btf_type *t;
+		int offset;
+
+		if (args->args[arg_no] != 0)
+			continue;
+
+		/* Program is validated already, so there is no need
+		 * to check if t is NULL.
+		 */
+		t = btf_type_skip_modifiers(bpf_dummy_ops_btf, param->type, NULL);
+		if (!btf_type_is_ptr(t))
+			continue;
+
+		offset = btf_ctx_arg_offset(bpf_dummy_ops_btf, func_proto, arg_no);
+		info = find_ctx_arg_info(prog->aux, offset);
+		if (info && type_may_be_null(info->reg_type))
+			continue;
+
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 extern const struct bpf_link_ops bpf_struct_ops_link_lops;
 
 int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr,
@@ -80,14 +132,21 @@ int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr,
 	const struct bpf_struct_ops *st_ops = &bpf_bpf_dummy_ops;
 	const struct btf_type *func_proto;
 	struct bpf_dummy_ops_test_args *args;
-	struct bpf_tramp_links *tlinks;
+	struct bpf_tramp_links *tlinks = NULL;
 	struct bpf_tramp_link *link = NULL;
 	void *image = NULL;
 	unsigned int op_idx;
+	u32 image_off = 0;
 	int prog_ret;
+	s32 type_id;
 	int err;
 
-	if (prog->aux->attach_btf_id != st_ops->type_id)
+	type_id = btf_find_by_name_kind(bpf_dummy_ops_btf,
+					bpf_bpf_dummy_ops.name,
+					BTF_KIND_STRUCT);
+	if (type_id < 0)
+		return -EINVAL;
+	if (prog->aux->attach_btf_id != type_id)
 		return -EOPNOTSUPP;
 
 	func_proto = prog->aux->attach_func_proto;
@@ -95,18 +154,15 @@ int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr,
 	if (IS_ERR(args))
 		return PTR_ERR(args);
 
-	tlinks = kcalloc(BPF_TRAMP_MAX, sizeof(*tlinks), GFP_KERNEL);
-	if (!tlinks) {
-		err = -ENOMEM;
+	err = check_test_run_args(prog, args);
+	if (err)
 		goto out;
-	}
 
-	image = bpf_jit_alloc_exec(PAGE_SIZE);
-	if (!image) {
+	tlinks = kcalloc(BPF_TRAMP_MAX, sizeof(*tlinks), GFP_KERNEL);
+	if (!tlinks) {
 		err = -ENOMEM;
 		goto out;
 	}
-	set_vm_flush_reset_perms(image);
 
 	link = kzalloc(sizeof(*link), GFP_USER);
 	if (!link) {
@@ -115,16 +171,21 @@ int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr,
 	}
 	/* prog doesn't take the ownership of the reference from caller */
 	bpf_prog_inc(prog);
-	bpf_link_init(&link->link, BPF_LINK_TYPE_STRUCT_OPS, &bpf_struct_ops_link_lops, prog);
+	bpf_link_init(&link->link, BPF_LINK_TYPE_STRUCT_OPS, &bpf_struct_ops_link_lops, prog,
+		      prog->expected_attach_type);
 
 	op_idx = prog->expected_attach_type;
 	err = bpf_struct_ops_prepare_trampoline(tlinks, link,
 						&st_ops->func_models[op_idx],
-						image, image + PAGE_SIZE);
+						&dummy_ops_test_ret_function,
+						&image, &image_off,
+						true);
 	if (err < 0)
 		goto out;
 
-	set_memory_rox((long)image, 1);
+	err = arch_protect_bpf_trampoline(image, PAGE_SIZE);
+	if (err)
+		goto out;
 	prog_ret = dummy_ops_call_op(image, args);
 
 	err = dummy_ops_copy_args(args);
@@ -134,7 +195,7 @@ int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr,
 		err = -EFAULT;
 out:
 	kfree(args);
-	bpf_jit_free_exec(image);
+	bpf_struct_ops_image_free(image);
 	if (link)
 		bpf_link_put(&link->link);
 	kfree(tlinks);
@@ -143,6 +204,7 @@ out:
 
 static int bpf_dummy_init(struct btf *btf)
 {
+	bpf_dummy_ops_btf = btf;
 	return 0;
 }
 
@@ -154,16 +216,30 @@ static bool bpf_dummy_ops_is_valid_access(int off, int size,
 	return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
 }
 
+static int bpf_dummy_ops_check_member(const struct btf_type *t,
+				      const struct btf_member *member,
+				      const struct bpf_prog *prog)
+{
+	u32 moff = __btf_member_bit_offset(t, member) / 8;
+
+	switch (moff) {
+	case offsetof(struct bpf_dummy_ops, test_sleepable):
+		break;
+	default:
+		if (prog->sleepable)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int bpf_dummy_ops_btf_struct_access(struct bpf_verifier_log *log,
 					   const struct bpf_reg_state *reg,
-					   int off, int size, enum bpf_access_type atype,
-					   u32 *next_btf_id,
-					   enum bpf_type_flag *flag)
+					   int off, int size)
 {
 	const struct btf_type *state;
 	const struct btf_type *t;
 	s32 type_id;
-	int err;
 
 	type_id = btf_find_by_name_kind(reg->btf, "bpf_dummy_ops_state",
 					BTF_KIND_STRUCT);
@@ -177,11 +253,12 @@ static int bpf_dummy_ops_btf_struct_access(struct bpf_verifier_log *log,
 		return -EACCES;
 	}
 
-	err = btf_struct_access(log, reg, off, size, atype, next_btf_id, flag);
-	if (err < 0)
-		return err;
+	if (off + size > sizeof(struct bpf_dummy_ops_state)) {
+		bpf_log(log, "write access at off %d with size %d\n", off, size);
+		return -EACCES;
+	}
 
-	return atype == BPF_READ ? err : NOT_INIT;
+	return NOT_INIT;
 }
 
 static const struct bpf_verifier_ops bpf_dummy_verifier_ops = {
@@ -196,20 +273,51 @@ static int bpf_dummy_init_member(const struct btf_type *t,
 	return -EOPNOTSUPP;
 }
 
-static int bpf_dummy_reg(void *kdata)
+static int bpf_dummy_reg(void *kdata, struct bpf_link *link)
 {
 	return -EOPNOTSUPP;
 }
 
-static void bpf_dummy_unreg(void *kdata)
+static void bpf_dummy_unreg(void *kdata, struct bpf_link *link)
 {
 }
 
-struct bpf_struct_ops bpf_bpf_dummy_ops = {
+static int bpf_dummy_ops__test_1(struct bpf_dummy_ops_state *cb__nullable)
+{
+	return 0;
+}
+
+static int bpf_dummy_test_2(struct bpf_dummy_ops_state *cb, int a1, unsigned short a2,
+			    char a3, unsigned long a4)
+{
+	return 0;
+}
+
+static int bpf_dummy_test_sleepable(struct bpf_dummy_ops_state *cb)
+{
+	return 0;
+}
+
+static struct bpf_dummy_ops __bpf_bpf_dummy_ops = {
+	.test_1 = bpf_dummy_ops__test_1,
+	.test_2 = bpf_dummy_test_2,
+	.test_sleepable = bpf_dummy_test_sleepable,
+};
+
+static struct bpf_struct_ops bpf_bpf_dummy_ops = {
 	.verifier_ops = &bpf_dummy_verifier_ops,
 	.init = bpf_dummy_init,
+	.check_member = bpf_dummy_ops_check_member,
 	.init_member = bpf_dummy_init_member,
 	.reg = bpf_dummy_reg,
 	.unreg = bpf_dummy_unreg,
 	.name = "bpf_dummy_ops",
+	.cfi_stubs = &__bpf_bpf_dummy_ops,
+	.owner = THIS_MODULE,
 };
+
+static int __init bpf_dummy_struct_ops_init(void)
+{
+	return register_bpf_struct_ops(&bpf_bpf_dummy_ops, bpf_dummy_ops);
+}
+late_initcall(bpf_dummy_struct_ops_init);