When this mode is turned on, "emit_zeroes" and "compact" have no effect, and embedded NUL characters always terminate printing of an array.
Signed-off-by: Blake Jones blakejones@google.com --- .../selftests/bpf/prog_tests/btf_dump.c | 106 ++++++++++++++++++ 1 file changed, 106 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dump.c b/tools/testing/selftests/bpf/prog_tests/btf_dump.c index c0a776feec23..2fde118d04c8 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf_dump.c +++ b/tools/testing/selftests/bpf/prog_tests/btf_dump.c @@ -879,6 +879,110 @@ static void test_btf_dump_var_data(struct btf *btf, struct btf_dump *d, "static int bpf_cgrp_storage_busy = (int)2", 2); }
+struct btf_dump_string_ctx { + struct btf *btf; + struct btf_dump *d; + char *str; + struct btf_dump_type_data_opts *opts; + int array_id; +}; + +static int btf_dump_one_string(struct btf_dump_string_ctx *ctx, + char *ptr, size_t ptr_sz, + const char *expected_val) +{ + size_t type_sz; + int ret; + + ctx->str[0] = '\0'; + type_sz = btf__resolve_size(ctx->btf, ctx->array_id); + ret = btf_dump__dump_type_data(ctx->d, ctx->array_id, ptr, ptr_sz, ctx->opts); + if (type_sz <= ptr_sz) { + if (!ASSERT_EQ(ret, type_sz, "failed/unexpected type_sz")) + return -EINVAL; + } else { + if (!ASSERT_EQ(ret, -E2BIG, "failed to return -E2BIG")) + return -EINVAL; + } + if (!ASSERT_STREQ(ctx->str, expected_val, "ensure expected/actual match")) + return -EFAULT; + return 0; +} + +static void btf_dump_strings(struct btf_dump_string_ctx *ctx) +{ + struct btf_dump_type_data_opts *opts = ctx->opts; + + opts->emit_strings = true; + + opts->compact = true; + opts->emit_zeroes = false; + + opts->skip_names = false; + btf_dump_one_string(ctx, "foo", 4, "(char[4])"foo""); + + opts->skip_names = true; + btf_dump_one_string(ctx, "foo", 4, ""foo""); + + /* This should have no effect. */ + opts->emit_zeroes = false; + btf_dump_one_string(ctx, "foo", 4, ""foo""); + + /* This should have no effect. */ + opts->compact = false; + btf_dump_one_string(ctx, "foo", 4, ""foo""); + + /* Non-printable characters come out as hex. */ + btf_dump_one_string(ctx, "fo\xff", 4, ""fo\xff""); + btf_dump_one_string(ctx, "fo\x7", 4, ""fo\x07""); + + /* Should get printed properly even though there's no NUL. */ + char food[4] = { 'f', 'o', 'o', 'd' }; + + btf_dump_one_string(ctx, food, 4, ""food""); + + /* The embedded NUL should terminate the string. */ + char embed[4] = { 'f', 'o', '\0', 'd' }; + + btf_dump_one_string(ctx, embed, 4, ""fo""); +} + +static void test_btf_dump_string_data(void) +{ + struct test_ctx t = {}; + char str[STRSIZE]; + struct btf_dump *d; + DECLARE_LIBBPF_OPTS(btf_dump_type_data_opts, opts); + struct btf_dump_string_ctx ctx; + int char_id, int_id, array_id; + + if (test_ctx__init(&t)) + return; + + d = btf_dump__new(t.btf, btf_dump_snprintf, str, NULL); + if (!ASSERT_OK_PTR(d, "could not create BTF dump")) + return; + + /* Generate BTF for a four-element char array. */ + char_id = btf__add_int(t.btf, "char", 1, BTF_INT_CHAR); + ASSERT_EQ(char_id, 1, "char_id"); + int_id = btf__add_int(t.btf, "int", 4, BTF_INT_SIGNED); + ASSERT_EQ(int_id, 2, "int_id"); + array_id = btf__add_array(t.btf, int_id, char_id, 4); + ASSERT_EQ(array_id, 3, "array_id"); + + ctx.btf = t.btf; + ctx.d = d; + ctx.str = str; + ctx.opts = &opts; + ctx.array_id = array_id; + + btf_dump_strings(&ctx); + + btf_dump__free(d); + test_ctx__free(&t); +} + static void test_btf_datasec(struct btf *btf, struct btf_dump *d, char *str, const char *name, const char *expected_val, void *data, size_t data_sz) @@ -970,6 +1074,8 @@ void test_btf_dump() { test_btf_dump_struct_data(btf, d, str); if (test__start_subtest("btf_dump: var_data")) test_btf_dump_var_data(btf, d, str); + if (test__start_subtest("btf_dump: string_data")) + test_btf_dump_string_data(); btf_dump__free(d); btf__free(btf);