bpf: Move kernel test kfuncs to bpf_testmod

Moving kernel test kfuncs into bpf_testmod kernel module, and adding
necessary init calls and BTF IDs records.

We need to keep following structs in kernel:
  struct prog_test_ref_kfunc
  struct prog_test_member (embedded in prog_test_ref_kfunc)

The reason is because they need to be marked as rcu safe (check test
prog mark_ref_as_untrusted_or_null) and such objects are being required
to be defined only in kernel at the moment (see rcu_safe_kptr check
in kernel).

We need to keep also dtor functions for both objects in kernel:
  bpf_kfunc_call_test_release
  bpf_kfunc_call_memb_release

We also keep the copy of these struct in bpf_testmod_kfunc.h, because
other test functions use them. This is unfortunate, but this is just
temporary solution until we are able to these structs them to bpf_testmod
completely.

As suggested by David adding bpf_testmod.ko make dependency for
bpf programs, so they are rebuilt if we change the bpf_testmod.ko
module.

Also adding missing __bpf_kfunc to bpf_kfunc_call_test4 functions.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230515133756.1658301-11-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 0 insertions, 201 deletions

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 98143b86a9dd..2321bd2f9964 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -561,29 +561,6 @@ __bpf_kfunc int bpf_modify_return_test(int a, int *b)
 	return a + *b;
 }
 
-__bpf_kfunc u64 bpf_kfunc_call_test1(struct sock *sk, u32 a, u64 b, u32 c, u64 d)
-{
-	return a + b + c + d;
-}
-
-__bpf_kfunc int bpf_kfunc_call_test2(struct sock *sk, u32 a, u32 b)
-{
-	return a + b;
-}
-
-__bpf_kfunc struct sock *bpf_kfunc_call_test3(struct sock *sk)
-{
-	return sk;
-}
-
-long noinline bpf_kfunc_call_test4(signed char a, short b, int c, long d)
-{
-	/* Provoke the compiler to assume that the caller has sign-extended a,
-	 * b and c on platforms where this is required (e.g. s390x).
-	 */
-	return (long)a + (long)b + (long)c + d;
-}
-
 int noinline bpf_fentry_shadow_test(int a)
 {
 	return a + 1;
@@ -606,32 +583,6 @@ struct prog_test_ref_kfunc {
 	refcount_t cnt;
 };
 
-static struct prog_test_ref_kfunc prog_test_struct = {
-	.a = 42,
-	.b = 108,
-	.next = &prog_test_struct,
-	.cnt = REFCOUNT_INIT(1),
-};
-
-__bpf_kfunc struct prog_test_ref_kfunc *
-bpf_kfunc_call_test_acquire(unsigned long *scalar_ptr)
-{
-	refcount_inc(&prog_test_struct.cnt);
-	return &prog_test_struct;
-}
-
-__bpf_kfunc void bpf_kfunc_call_test_offset(struct prog_test_ref_kfunc *p)
-{
-	WARN_ON_ONCE(1);
-}
-
-__bpf_kfunc struct prog_test_member *
-bpf_kfunc_call_memb_acquire(void)
-{
-	WARN_ON_ONCE(1);
-	return NULL;
-}
-
 __bpf_kfunc void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p)
 {
 	refcount_dec(&p->cnt);
@@ -641,134 +592,6 @@ __bpf_kfunc void bpf_kfunc_call_memb_release(struct prog_test_member *p)
 {
 }
 
-__bpf_kfunc void bpf_kfunc_call_memb1_release(struct prog_test_member1 *p)
-{
-	WARN_ON_ONCE(1);
-}
-
-static int *__bpf_kfunc_call_test_get_mem(struct prog_test_ref_kfunc *p, const int size)
-{
-	if (size > 2 * sizeof(int))
-		return NULL;
-
-	return (int *)p;
-}
-
-__bpf_kfunc int *bpf_kfunc_call_test_get_rdwr_mem(struct prog_test_ref_kfunc *p,
-						  const int rdwr_buf_size)
-{
-	return __bpf_kfunc_call_test_get_mem(p, rdwr_buf_size);
-}
-
-__bpf_kfunc int *bpf_kfunc_call_test_get_rdonly_mem(struct prog_test_ref_kfunc *p,
-						    const int rdonly_buf_size)
-{
-	return __bpf_kfunc_call_test_get_mem(p, rdonly_buf_size);
-}
-
-/* the next 2 ones can't be really used for testing expect to ensure
- * that the verifier rejects the call.
- * Acquire functions must return struct pointers, so these ones are
- * failing.
- */
-__bpf_kfunc int *bpf_kfunc_call_test_acq_rdonly_mem(struct prog_test_ref_kfunc *p,
-						    const int rdonly_buf_size)
-{
-	return __bpf_kfunc_call_test_get_mem(p, rdonly_buf_size);
-}
-
-__bpf_kfunc void bpf_kfunc_call_int_mem_release(int *p)
-{
-}
-
-struct prog_test_pass1 {
-	int x0;
-	struct {
-		int x1;
-		struct {
-			int x2;
-			struct {
-				int x3;
-			};
-		};
-	};
-};
-
-struct prog_test_pass2 {
-	int len;
-	short arr1[4];
-	struct {
-		char arr2[4];
-		unsigned long arr3[8];
-	} x;
-};
-
-struct prog_test_fail1 {
-	void *p;
-	int x;
-};
-
-struct prog_test_fail2 {
-	int x8;
-	struct prog_test_pass1 x;
-};
-
-struct prog_test_fail3 {
-	int len;
-	char arr1[2];
-	char arr2[];
-};
-
-__bpf_kfunc void bpf_kfunc_call_test_pass_ctx(struct __sk_buff *skb)
-{
-}
-
-__bpf_kfunc void bpf_kfunc_call_test_pass1(struct prog_test_pass1 *p)
-{
-}
-
-__bpf_kfunc void bpf_kfunc_call_test_pass2(struct prog_test_pass2 *p)
-{
-}
-
-__bpf_kfunc void bpf_kfunc_call_test_fail1(struct prog_test_fail1 *p)
-{
-}
-
-__bpf_kfunc void bpf_kfunc_call_test_fail2(struct prog_test_fail2 *p)
-{
-}
-
-__bpf_kfunc void bpf_kfunc_call_test_fail3(struct prog_test_fail3 *p)
-{
-}
-
-__bpf_kfunc void bpf_kfunc_call_test_mem_len_pass1(void *mem, int mem__sz)
-{
-}
-
-__bpf_kfunc void bpf_kfunc_call_test_mem_len_fail1(void *mem, int len)
-{
-}
-
-__bpf_kfunc void bpf_kfunc_call_test_mem_len_fail2(u64 *mem, int len)
-{
-}
-
-__bpf_kfunc void bpf_kfunc_call_test_ref(struct prog_test_ref_kfunc *p)
-{
-	/* p != NULL, but p->cnt could be 0 */
-}
-
-__bpf_kfunc void bpf_kfunc_call_test_destructive(void)
-{
-}
-
-__bpf_kfunc static u32 bpf_kfunc_call_test_static_unused_arg(u32 arg, u32 unused)
-{
-	return arg;
-}
-
 __diag_pop();
 
 BTF_SET8_START(bpf_test_modify_return_ids)
@@ -782,32 +605,8 @@ static const struct btf_kfunc_id_set bpf_test_modify_return_set = {
 };
 
 BTF_SET8_START(test_sk_check_kfunc_ids)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test1)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test2)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test3)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test4)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_acquire, KF_ACQUIRE | KF_RET_NULL)
-BTF_ID_FLAGS(func, bpf_kfunc_call_memb_acquire, KF_ACQUIRE | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_kfunc_call_test_release, KF_RELEASE)
 BTF_ID_FLAGS(func, bpf_kfunc_call_memb_release, KF_RELEASE)
-BTF_ID_FLAGS(func, bpf_kfunc_call_memb1_release, KF_RELEASE)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_get_rdwr_mem, KF_RET_NULL)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_get_rdonly_mem, KF_RET_NULL)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_acq_rdonly_mem, KF_ACQUIRE | KF_RET_NULL)
-BTF_ID_FLAGS(func, bpf_kfunc_call_int_mem_release, KF_RELEASE)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_pass_ctx)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_pass1)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_pass2)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_fail1)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_fail2)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_fail3)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_pass1)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail1)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail2)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_ref, KF_TRUSTED_ARGS | KF_RCU)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_destructive, KF_DESTRUCTIVE)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_static_unused_arg)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_offset)
 BTF_SET8_END(test_sk_check_kfunc_ids)
 
 static void *bpf_test_init(const union bpf_attr *kattr, u32 user_size,