[PATCH v5 bpf-next 13/14] selftests/bpf: add tp_btf CO-RE reloc test for modules

[Andrii Nakryiko]

Add another CO-RE relocation test for kernel module relocations. This time for
tp_btf with direct memory reads.

Signed-off-by: Andrii Nakryiko <and...@kernel.org>
---
 .../selftests/bpf/prog_tests/core_reloc.c     |  3 +-
 .../bpf/progs/test_core_reloc_module.c        | 32 ++++++++++++++++++-
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c 
b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
index bb980848cd77..06eb956ff7bb 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
@@ -514,7 +514,8 @@ static struct core_reloc_test_case test_cases[] = {
        },
 
        /* validate we can find kernel module BTF types for relocs/attach */
-       MODULES_CASE("module", "raw_tp/bpf_testmod_test_read", 
"bpf_testmod_test_read"),
+       MODULES_CASE("module_probed", "raw_tp/bpf_testmod_test_read", 
"bpf_testmod_test_read"),
+       MODULES_CASE("module_direct", "tp_btf/bpf_testmod_test_read", NULL),
 
        /* validate BPF program can use multiple flavors to match against
         * single target BTF type
diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_module.c 
b/tools/testing/selftests/bpf/progs/test_core_reloc_module.c
index d1840c1a9d36..56363959f7b0 100644
--- a/tools/testing/selftests/bpf/progs/test_core_reloc_module.c
+++ b/tools/testing/selftests/bpf/progs/test_core_reloc_module.c
@@ -36,7 +36,7 @@ struct core_reloc_module_output {
 };
 
 SEC("raw_tp/bpf_testmod_test_read")
-int BPF_PROG(test_core_module,
+int BPF_PROG(test_core_module_probed,
             struct task_struct *task,
             struct bpf_testmod_test_read_ctx *read_ctx)
 {
@@ -64,3 +64,33 @@ int BPF_PROG(test_core_module,
 
        return 0;
 }
+
+SEC("tp_btf/bpf_testmod_test_read")
+int BPF_PROG(test_core_module_direct,
+            struct task_struct *task,
+            struct bpf_testmod_test_read_ctx *read_ctx)
+{
+       struct core_reloc_module_output *out = (void *)&data.out;
+       __u64 pid_tgid = bpf_get_current_pid_tgid();
+       __u32 real_tgid = (__u32)(pid_tgid >> 32);
+       __u32 real_pid = (__u32)pid_tgid;
+
+       if (data.my_pid_tgid != pid_tgid)
+               return 0;
+
+       if (task->pid != real_pid || task->tgid != real_tgid)
+               return 0;
+
+       out->len = read_ctx->len;
+       out->off = read_ctx->off;
+
+       out->read_ctx_sz = bpf_core_type_size(struct bpf_testmod_test_read_ctx);
+       out->read_ctx_exists = bpf_core_type_exists(struct 
bpf_testmod_test_read_ctx);
+       out->buf_exists = bpf_core_field_exists(read_ctx->buf);
+       out->off_exists = bpf_core_field_exists(read_ctx->off);
+       out->len_exists = bpf_core_field_exists(read_ctx->len);
+
+       out->comm_len = BPF_CORE_READ_STR_INTO(&out->comm, task, comm);
+
+       return 0;
+}
-- 
2.24.1