Commit bc9ed69c authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add tp_btf CO-RE reloc test for modules 



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

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-14-andrii@kernel.org
parent 91abb4a6

tools/testing/selftests/bpf/prog_tests/core_reloc.c

+2 −1
Original line number Diff line number Diff line
@@ -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

tools/testing/selftests/bpf/progs/test_core_reloc_module.c

+31 −1
Original line number Diff line number Diff line
@@ -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;

}