From 95226f5a36695fd5740e130016d9ed697cfb2bad Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Wed, 3 Jan 2024 17:38:47 -0800 Subject: selftests/bpf: add __arg_ctx BTF rewrite test Add a test validating that libbpf uploads BTF and func_info with rewritten type information for arguments of global subprogs that are marked with __arg_ctx tag. Suggested-by: Eduard Zingerman Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20240104013847.3875810-10-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- .../selftests/bpf/prog_tests/test_global_funcs.c | 106 +++++++++++++++++++++ 1 file changed, 106 insertions(+) (limited to 'tools/testing/selftests/bpf/prog_tests/test_global_funcs.c') diff --git a/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c b/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c index e0879df38639..67d4ef9e62b3 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c +++ b/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c @@ -20,6 +20,109 @@ #include "test_global_func17.skel.h" #include "test_global_func_ctx_args.skel.h" +#include "bpf/libbpf_internal.h" +#include "btf_helpers.h" + +static void check_ctx_arg_type(const struct btf *btf, const struct btf_param *p) +{ + const struct btf_type *t; + const char *s; + + t = btf__type_by_id(btf, p->type); + if (!ASSERT_EQ(btf_kind(t), BTF_KIND_PTR, "ptr_t")) + return; + + s = btf_type_raw_dump(btf, t->type); + if (!ASSERT_HAS_SUBSTR(s, "STRUCT 'bpf_perf_event_data' size=0 vlen=0", + "ctx_struct_t")) + return; +} + +static void subtest_ctx_arg_rewrite(void) +{ + struct test_global_func_ctx_args *skel = NULL; + struct bpf_prog_info info; + char func_info_buf[1024] __attribute__((aligned(8))); + struct bpf_func_info_min *rec; + struct btf *btf = NULL; + __u32 info_len = sizeof(info); + int err, fd, i; + + skel = test_global_func_ctx_args__open(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + bpf_program__set_autoload(skel->progs.arg_tag_ctx_perf, true); + + err = test_global_func_ctx_args__load(skel); + if (!ASSERT_OK(err, "skel_load")) + goto out; + + memset(&info, 0, sizeof(info)); + info.func_info = ptr_to_u64(&func_info_buf); + info.nr_func_info = 3; + info.func_info_rec_size = sizeof(struct bpf_func_info_min); + + fd = bpf_program__fd(skel->progs.arg_tag_ctx_perf); + err = bpf_prog_get_info_by_fd(fd, &info, &info_len); + if (!ASSERT_OK(err, "prog_info")) + goto out; + + if (!ASSERT_EQ(info.nr_func_info, 3, "nr_func_info")) + goto out; + + btf = btf__load_from_kernel_by_id(info.btf_id); + if (!ASSERT_OK_PTR(btf, "obj_kern_btf")) + goto out; + + rec = (struct bpf_func_info_min *)func_info_buf; + for (i = 0; i < info.nr_func_info; i++, rec = (void *)rec + info.func_info_rec_size) { + const struct btf_type *fn_t, *proto_t; + const char *name; + + if (rec->insn_off == 0) + continue; /* main prog, skip */ + + fn_t = btf__type_by_id(btf, rec->type_id); + if (!ASSERT_OK_PTR(fn_t, "fn_type")) + goto out; + if (!ASSERT_EQ(btf_kind(fn_t), BTF_KIND_FUNC, "fn_type_kind")) + goto out; + proto_t = btf__type_by_id(btf, fn_t->type); + if (!ASSERT_OK_PTR(proto_t, "proto_type")) + goto out; + + name = btf__name_by_offset(btf, fn_t->name_off); + if (strcmp(name, "subprog_ctx_tag") == 0) { + /* int subprog_ctx_tag(void *ctx __arg_ctx) */ + if (!ASSERT_EQ(btf_vlen(proto_t), 1, "arg_cnt")) + goto out; + + /* arg 0 is PTR -> STRUCT bpf_perf_event_data */ + check_ctx_arg_type(btf, &btf_params(proto_t)[0]); + } else if (strcmp(name, "subprog_multi_ctx_tags") == 0) { + /* int subprog_multi_ctx_tags(void *ctx1 __arg_ctx, + * struct my_struct *mem, + * void *ctx2 __arg_ctx) + */ + if (!ASSERT_EQ(btf_vlen(proto_t), 3, "arg_cnt")) + goto out; + + /* arg 0 is PTR -> STRUCT bpf_perf_event_data */ + check_ctx_arg_type(btf, &btf_params(proto_t)[0]); + /* arg 2 is PTR -> STRUCT bpf_perf_event_data */ + check_ctx_arg_type(btf, &btf_params(proto_t)[2]); + } else { + ASSERT_FAIL("unexpected subprog %s", name); + goto out; + } + } + +out: + btf__free(btf); + test_global_func_ctx_args__destroy(skel); +} + void test_test_global_funcs(void) { RUN_TESTS(test_global_func1); @@ -40,4 +143,7 @@ void test_test_global_funcs(void) RUN_TESTS(test_global_func16); RUN_TESTS(test_global_func17); RUN_TESTS(test_global_func_ctx_args); + + if (test__start_subtest("ctx_arg_rewrite")) + subtest_ctx_arg_rewrite(); } -- cgit v1.2.3