Merge branch 'bpf-retire-the-unsupported_ops-usage-in-struct_ops'

Martin KaFai Lau says:

====================
bpf: Retire the unsupported_ops usage in struct_ops

From: Martin KaFai Lau <[email protected]>

This series retires the unsupported_ops usage and depends on the
null-ness check on the cfi_stubs instead.

Please see individual patches for details.

v2:
- Fixed a gcc compiler warning on Patch 1.
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>

1 files changed, 14 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index fd28c1157bd3..3687a40b61c6 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -1024,6 +1024,11 @@ static void bpf_testmod_test_2(int a, int b)
 {
 }
 
+static int bpf_testmod_tramp(int value)
+{
+	return 0;
+}
+
 static int bpf_testmod_ops__test_maybe_null(int dummy,
 					    struct task_struct *task__nullable)
 {
@@ -1080,6 +1085,7 @@ static int bpf_testmod_init(void)
 			.kfunc_btf_id	= bpf_testmod_dtor_ids[1]
 		},
 	};
+	void **tramp;
 	int ret;
 
 	ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_UNSPEC, &bpf_testmod_common_kfunc_set);
@@ -1103,6 +1109,14 @@ static int bpf_testmod_init(void)
 	ret = register_bpf_testmod_uprobe();
 	if (ret < 0)
 		return ret;
+
+	/* Ensure nothing is between tramp_1..tramp_40 */
+	BUILD_BUG_ON(offsetof(struct bpf_testmod_ops, tramp_1) + 40 * sizeof(long) !=
+		     offsetofend(struct bpf_testmod_ops, tramp_40));
+	tramp = (void **)&__bpf_testmod_ops.tramp_1;
+	while (tramp <= (void **)&__bpf_testmod_ops.tramp_40)
+		*tramp++ = bpf_testmod_tramp;
+
 	return 0;
 }