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>

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 98143b86a9ddf1fe3699c2e15073fd9c9a8fe05d..2321bd2f9964f3c233380ae4829a00dfdf1a43bc 100644 (file)
--- 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,

diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index 52785ba671e6c3b4511ae2b24a9d6f6a631f829f..cf216041876ca553741e3c2948bd2f283d6dcc48 100644 (file)
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -9,6 +9,7 @@
 #include <linux/sysfs.h>
 #include <linux/tracepoint.h>
 #include "bpf_testmod.h"
+#include "bpf_testmod_kfunc.h"
 
 #define CREATE_TRACE_POINTS
 #include "bpf_testmod-events.h"
@@ -289,8 +290,171 @@ static const struct btf_kfunc_id_set bpf_testmod_common_kfunc_set = {
        .set   = &bpf_testmod_common_kfunc_ids,
 };
 
+__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;
+}
+
+__bpf_kfunc 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;
+}
+
+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_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)
+{
+}
+
+__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;
+}
+
 BTF_SET8_START(bpf_testmod_check_kfunc_ids)
 BTF_ID_FLAGS(func, bpf_testmod_test_mod_kfunc)
+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_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_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_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_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(bpf_testmod_check_kfunc_ids)
 
 static const struct btf_kfunc_id_set bpf_testmod_kfunc_set = {
@@ -312,6 +476,8 @@ static int bpf_testmod_init(void)
 
        ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_UNSPEC, &bpf_testmod_common_kfunc_set);
        ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_testmod_kfunc_set);
+       ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &bpf_testmod_kfunc_set);
+       ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &bpf_testmod_kfunc_set);
        if (ret < 0)
                return ret;
        if (bpf_fentry_test1(0) < 0)

diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h
index 57f6166911f848fb411ba8bfb3d608391c3ead47..9693c626646b9a13ea715fa6022e1229c56ee8ff 100644 (file)
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h
@@ -8,8 +8,62 @@
 #include <bpf/bpf_helpers.h>
 #else
 #define __ksym
+struct prog_test_member1 {
+       int a;
+};
+
+struct prog_test_member {
+       struct prog_test_member1 m;
+       int c;
+};
+
+struct prog_test_ref_kfunc {
+       int a;
+       int b;
+       struct prog_test_member memb;
+       struct prog_test_ref_kfunc *next;
+       refcount_t cnt;
+};
 #endif
 
+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[];
+};
+
 struct prog_test_ref_kfunc *
 bpf_kfunc_call_test_acquire(unsigned long *scalar_ptr) __ksym;
 void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) __ksym;
@@ -20,7 +74,13 @@ int *bpf_kfunc_call_test_get_rdwr_mem(struct prog_test_ref_kfunc *p, const int r
 int *bpf_kfunc_call_test_get_rdonly_mem(struct prog_test_ref_kfunc *p, const int rdonly_buf_size) __ksym;
 int *bpf_kfunc_call_test_acq_rdonly_mem(struct prog_test_ref_kfunc *p, const int rdonly_buf_size) __ksym;
 void bpf_kfunc_call_int_mem_release(int *p) __ksym;
+
+/* The bpf_kfunc_call_test_static_unused_arg is defined as static,
+ * but bpf program compilation needs to see it as global symbol.
+ */
+#ifndef __KERNEL__
 u32 bpf_kfunc_call_test_static_unused_arg(u32 arg, u32 unused) __ksym;
+#endif
 
 void bpf_testmod_test_mod_kfunc(int i) __ksym;