tools/bpf: enhance test_btf file testing to test func info

Change the bpf programs test_btf_haskv.c and test_btf_nokv.c to
have two sections, and enhance test_btf.c test_file feature
to test btf func_info returned by the kernel.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c
index 8fd3a16fea4d80c7e42e5a0f1305c5e652f6efd1..7b1b160d6e67b5b891c32d97c8f7c9b79a28d8ec 100644 (file)
--- a/tools/testing/selftests/bpf/test_btf.c
+++ b/tools/testing/selftests/bpf/test_btf.c
@@ -2434,13 +2434,13 @@ static struct btf_file_test file_tests[] = {
 },
 };
 
-static int file_has_btf_elf(const char *fn)
+static int file_has_btf_elf(const char *fn, bool *has_btf_ext)
 {
        Elf_Scn *scn = NULL;
        GElf_Ehdr ehdr;
+       int ret = 0;
        int elf_fd;
        Elf *elf;
-       int ret;
 
        if (CHECK(elf_version(EV_CURRENT) == EV_NONE,
                  "elf_version(EV_CURRENT) == EV_NONE"))
@@ -2472,14 +2472,12 @@ static int file_has_btf_elf(const char *fn)
                }
 
                sh_name = elf_strptr(elf, ehdr.e_shstrndx, sh.sh_name);
-               if (!strcmp(sh_name, BTF_ELF_SEC)) {
+               if (!strcmp(sh_name, BTF_ELF_SEC))
                        ret = 1;
-                       goto done;
-               }
+               if (!strcmp(sh_name, BTF_EXT_ELF_SEC))
+                       *has_btf_ext = true;
        }
 
-       ret = 0;
-
 done:
        close(elf_fd);
        elf_end(elf);
@@ -2489,15 +2487,24 @@ done:
 static int do_test_file(unsigned int test_num)
 {
        const struct btf_file_test *test = &file_tests[test_num - 1];
+       const char *expected_fnames[] = {"_dummy_tracepoint",
+                                        "test_long_fname_1",
+                                        "test_long_fname_2"};
+       struct bpf_prog_info info = {};
        struct bpf_object *obj = NULL;
+       struct bpf_func_info *finfo;
        struct bpf_program *prog;
+       __u32 info_len, rec_size;
+       bool has_btf_ext = false;
+       struct btf *btf = NULL;
+       void *func_info = NULL;
        struct bpf_map *map;
-       int err;
+       int i, err, prog_fd;
 
        fprintf(stderr, "BTF libbpf test[%u] (%s): ", test_num,
                test->file);
 
-       err = file_has_btf_elf(test->file);
+       err = file_has_btf_elf(test->file, &has_btf_ext);
        if (err == -1)
                return err;
 
@@ -2525,6 +2532,7 @@ static int do_test_file(unsigned int test_num)
        err = bpf_object__load(obj);
        if (CHECK(err < 0, "bpf_object__load: %d", err))
                goto done;
+       prog_fd = bpf_program__fd(prog);
 
        map = bpf_object__find_map_by_name(obj, "btf_map");
        if (CHECK(!map, "btf_map not found")) {
@@ -2539,9 +2547,100 @@ static int do_test_file(unsigned int test_num)
                  test->btf_kv_notfound))
                goto done;
 
+       if (!jit_enabled || !has_btf_ext)
+               goto skip_jit;
+
+       /* get necessary program info */
+       info_len = sizeof(struct bpf_prog_info);
+       err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
+
+       if (CHECK(err == -1, "invalid get info (1st) errno:%d", errno)) {
+               fprintf(stderr, "%s\n", btf_log_buf);
+               err = -1;
+               goto done;
+       }
+       if (CHECK(info.func_info_cnt != 3,
+                 "incorrect info.func_info_cnt (1st) %d",
+                 info.func_info_cnt)) {
+               err = -1;
+               goto done;
+       }
+       rec_size = info.func_info_rec_size;
+       if (CHECK(rec_size < 4,
+                 "incorrect info.func_info_rec_size (1st) %d\n", rec_size)) {
+               err = -1;
+               goto done;
+       }
+
+       func_info = malloc(info.func_info_cnt * rec_size);
+       if (CHECK(!func_info, "out of memeory")) {
+               err = -1;
+               goto done;
+       }
+
+       /* reset info to only retrieve func_info related data */
+       memset(&info, 0, sizeof(info));
+       info.func_info_cnt = 3;
+       info.func_info_rec_size = rec_size;
+       info.func_info = ptr_to_u64(func_info);
+
+       err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
+
+       if (CHECK(err == -1, "invalid get info (2nd) errno:%d", errno)) {
+               fprintf(stderr, "%s\n", btf_log_buf);
+               err = -1;
+               goto done;
+       }
+       if (CHECK(info.func_info_cnt != 3,
+                 "incorrect info.func_info_cnt (2nd) %d",
+                 info.func_info_cnt)) {
+               err = -1;
+               goto done;
+       }
+       if (CHECK(info.func_info_rec_size != rec_size,
+                 "incorrect info.func_info_rec_size (2nd) %d",
+                 info.func_info_rec_size)) {
+               err = -1;
+               goto done;
+       }
+
+       err = btf_get_from_id(info.btf_id, &btf);
+       if (CHECK(err, "cannot get btf from kernel, err: %d", err))
+               goto done;
+
+       /* check three functions */
+       finfo = func_info;
+       for (i = 0; i < 3; i++) {
+               const struct btf_type *t;
+               const char *fname;
+
+               t = btf__type_by_id(btf, finfo->type_id);
+               if (CHECK(!t, "btf__type_by_id failure: id %u",
+                         finfo->type_id)) {
+                       err = -1;
+                       goto done;
+               }
+
+               fname = btf__name_by_offset(btf, t->name_off);
+               err = strcmp(fname, expected_fnames[i]);
+               /* for the second and third functions in .text section,
+                * the compiler may order them either way.
+                */
+               if (i && err)
+                       err = strcmp(fname, expected_fnames[3 - i]);
+               if (CHECK(err, "incorrect fname %s", fname ? : "")) {
+                       err = -1;
+                       goto done;
+               }
+
+               finfo = (void *)finfo + rec_size;
+       }
+
+skip_jit:
        fprintf(stderr, "OK");
 
 done:
+       free(func_info);
        bpf_object__close(obj);
        return err;
 }

diff --git a/tools/testing/selftests/bpf/test_btf_haskv.c b/tools/testing/selftests/bpf/test_btf_haskv.c
index b21b876f475d8a972586b6181ef1328fc2bfd13a..e5c79fe0ffdb22f5ee797c3f1d512452613587f4 100644 (file)
--- a/tools/testing/selftests/bpf/test_btf_haskv.c
+++ b/tools/testing/selftests/bpf/test_btf_haskv.c
@@ -24,8 +24,8 @@ struct dummy_tracepoint_args {
        struct sock *sock;
 };
 
-SEC("dummy_tracepoint")
-int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
+__attribute__((noinline))
+static int test_long_fname_2(struct dummy_tracepoint_args *arg)
 {
        struct ipv_counts *counts;
        int key = 0;
@@ -42,4 +42,16 @@ int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
        return 0;
 }
 
+__attribute__((noinline))
+static int test_long_fname_1(struct dummy_tracepoint_args *arg)
+{
+       return test_long_fname_2(arg);
+}
+
+SEC("dummy_tracepoint")
+int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
+{
+       return test_long_fname_1(arg);
+}
+
 char _license[] SEC("license") = "GPL";

diff --git a/tools/testing/selftests/bpf/test_btf_nokv.c b/tools/testing/selftests/bpf/test_btf_nokv.c
index 0ed8e088eebf9ed58a8f87c9c02ce0b70f360497..434188c37774311ee84dacdeebec717e7336c467 100644 (file)
--- a/tools/testing/selftests/bpf/test_btf_nokv.c
+++ b/tools/testing/selftests/bpf/test_btf_nokv.c
@@ -22,8 +22,8 @@ struct dummy_tracepoint_args {
        struct sock *sock;
 };
 
-SEC("dummy_tracepoint")
-int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
+__attribute__((noinline))
+static int test_long_fname_2(struct dummy_tracepoint_args *arg)
 {
        struct ipv_counts *counts;
        int key = 0;
@@ -40,4 +40,16 @@ int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
        return 0;
 }
 
+__attribute__((noinline))
+static int test_long_fname_1(struct dummy_tracepoint_args *arg)
+{
+       return test_long_fname_2(arg);
+}
+
+SEC("dummy_tracepoint")
+int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
+{
+       return test_long_fname_1(arg);
+}
+
 char _license[] SEC("license") = "GPL";