LXR linux/tools/testing/selftests/bpf/prog_tests/btf

   1// SPDX-License-Identifier: GPL-2.0
   2#include <test_progs.h>
   3#include <bpf/btf.h>
   4
   5static int duration = 0;
   6
   7void btf_dump_printf(void *ctx, const char *fmt, va_list args)
   8{
   9        vfprintf(ctx, fmt, args);
  10}
  11
  12static struct btf_dump_test_case {
  13        const char *name;
  14        const char *file;
  15        bool known_ptr_sz;
  16        struct btf_dump_opts opts;
  17} btf_dump_test_cases[] = {
  18        {"btf_dump: syntax", "btf_dump_test_case_syntax", true, {}},
  19        {"btf_dump: ordering", "btf_dump_test_case_ordering", false, {}},
  20        {"btf_dump: padding", "btf_dump_test_case_padding", true, {}},
  21        {"btf_dump: packing", "btf_dump_test_case_packing", true, {}},
  22        {"btf_dump: bitfields", "btf_dump_test_case_bitfields", true, {}},
  23        {"btf_dump: multidim", "btf_dump_test_case_multidim", false, {}},
  24        {"btf_dump: namespacing", "btf_dump_test_case_namespacing", false, {}},
  25};
  26
  27static int btf_dump_all_types(const struct btf *btf,
  28                              const struct btf_dump_opts *opts)
  29{
  30        size_t type_cnt = btf__get_nr_types(btf);
  31        struct btf_dump *d;
  32        int err = 0, id;
  33
  34        d = btf_dump__new(btf, NULL, opts, btf_dump_printf);
  35        if (IS_ERR(d))
  36                return PTR_ERR(d);
  37
  38        for (id = 1; id <= type_cnt; id++) {
  39                err = btf_dump__dump_type(d, id);
  40                if (err)
  41                        goto done;
  42        }
  43
  44done:
  45        btf_dump__free(d);
  46        return err;
  47}
  48
  49static int test_btf_dump_case(int n, struct btf_dump_test_case *t)
  50{
  51        char test_file[256], out_file[256], diff_cmd[1024];
  52        struct btf *btf = NULL;
  53        int err = 0, fd = -1;
  54        FILE *f = NULL;
  55
  56        snprintf(test_file, sizeof(test_file), "%s.o", t->file);
  57
  58        btf = btf__parse_elf(test_file, NULL);
  59        if (CHECK(IS_ERR(btf), "btf_parse_elf",
  60            "failed to load test BTF: %ld\n", PTR_ERR(btf))) {
  61                err = -PTR_ERR(btf);
  62                btf = NULL;
  63                goto done;
  64        }
  65
  66        /* tests with t->known_ptr_sz have no "long" or "unsigned long" type,
  67         * so it's impossible to determine correct pointer size; but if they
  68         * do, it should be 8 regardless of host architecture, becaues BPF
  69         * target is always 64-bit
  70         */
  71        if (!t->known_ptr_sz) {
  72                btf__set_pointer_size(btf, 8);
  73        } else {
  74                CHECK(btf__pointer_size(btf) != 8, "ptr_sz", "exp %d, got %zu\n",
  75                      8, btf__pointer_size(btf));
  76        }
  77
  78        snprintf(out_file, sizeof(out_file), "/tmp/%s.output.XXXXXX", t->file);
  79        fd = mkstemp(out_file);
  80        if (CHECK(fd < 0, "create_tmp", "failed to create file: %d\n", fd)) {
  81                err = fd;
  82                goto done;
  83        }
  84        f = fdopen(fd, "w");
  85        if (CHECK(f == NULL, "open_tmp",  "failed to open file: %s(%d)\n",
  86                  strerror(errno), errno)) {
  87                close(fd);
  88                goto done;
  89        }
  90
  91        t->opts.ctx = f;
  92        err = btf_dump_all_types(btf, &t->opts);
  93        fclose(f);
  94        close(fd);
  95        if (CHECK(err, "btf_dump", "failure during C dumping: %d\n", err)) {
  96                goto done;
  97        }
  98
  99        snprintf(test_file, sizeof(test_file), "progs/%s.c", t->file);
 100        if (access(test_file, R_OK) == -1)
 101                /*
 102                 * When the test is run with O=, kselftest copies TEST_FILES
 103                 * without preserving the directory structure.
 104                 */
 105                snprintf(test_file, sizeof(test_file), "%s.c", t->file);
 106        /*
 107         * Diff test output and expected test output, contained between
 108         * START-EXPECTED-OUTPUT and END-EXPECTED-OUTPUT lines in test case.
 109         * For expected output lines, everything before '*' is stripped out.
 110         * Also lines containing comment start and comment end markers are
 111         * ignored. 
 112         */
 113        snprintf(diff_cmd, sizeof(diff_cmd),
 114                 "awk '/START-EXPECTED-OUTPUT/{out=1;next} "
 115                 "/END-EXPECTED-OUTPUT/{out=0} "
 116                 "/\\/\\*|\\*\\//{next} " /* ignore comment start/end lines */
 117                 "out {sub(/^[ \\t]*\\*/, \"\"); print}' '%s' | diff -u - '%s'",
 118                 test_file, out_file);
 119        err = system(diff_cmd);
 120        if (CHECK(err, "diff",
 121                  "differing test output, output=%s, err=%d, diff cmd:\n%s\n",
 122                  out_file, err, diff_cmd))
 123                goto done;
 124
 125        remove(out_file);
 126
 127done:
 128        btf__free(btf);
 129        return err;
 130}
 131
 132void test_btf_dump() {
 133        int i;
 134
 135        for (i = 0; i < ARRAY_SIZE(btf_dump_test_cases); i++) {
 136                struct btf_dump_test_case *t = &btf_dump_test_cases[i];
 137
 138                if (!test__start_subtest(t->name))
 139                        continue;
 140
 141                test_btf_dump_case(i, &btf_dump_test_cases[i]);
 142        }
 143}
 144