On Tue, Feb 15, 2022 at 2:59 PM Mauricio Vásquez <mauricio@xxxxxxxxxx> wrote:
>
> This commit reuses the core_reloc test to check if the BTF files
> generated with "bpftool gen min_core_btf" are correct. This introduces
> test_core_btfgen() that runs all the core_reloc tests, but this time
> the source BTF files are generated by using "bpftool gen min_core_btf".
>
> The goal of this test is to check that the generated files are usable,
> and not to check if the algorithm is creating an optimized BTF file.
>
> Signed-off-by: Mauricio Vásquez <mauricio@xxxxxxxxxx>
> Signed-off-by: Rafael David Tinoco <rafael.tinoco@xxxxxxxxxxx>
> Signed-off-by: Lorenzo Fontana <lorenzo.fontana@xxxxxxxxxx>
> Signed-off-by: Leonardo Di Donato <leonardo.didonato@xxxxxxxxxx>
> ---
> .../selftests/bpf/prog_tests/core_reloc.c | 50 ++++++++++++++++++-
> 1 file changed, 48 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
> index 68e4c8dafa00..fa2908879c77 100644
> --- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
> +++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
> @@ -2,6 +2,7 @@
> #include <test_progs.h>
> #include "progs/core_reloc_types.h"
> #include "bpf_testmod/bpf_testmod.h"
> +#include <linux/limits.h>
> #include <sys/mman.h>
> #include <sys/syscall.h>
> #include <bpf/btf.h>
> @@ -836,13 +837,27 @@ static size_t roundup_page(size_t sz)
> return (sz + page_size - 1) / page_size * page_size;
> }
>
> -void test_core_reloc(void)
> +static int run_btfgen(const char *src_btf, const char *dst_btf, const char *objpath)
> +{
> + char command[4096];
> + int n;
> +
> + n = snprintf(command, sizeof(command),
> + "./tools/build/bpftool/bpftool gen min_core_btf %s %s %s",
> + src_btf, dst_btf, objpath);
> + if (n < 0 || n >= sizeof(command))
> + return -1;
> +
> + return system(command);
> +}
> +
> +static void run_core_reloc_tests(bool use_btfgen)
> {
> const size_t mmap_sz = roundup_page(sizeof(struct data));
> DECLARE_LIBBPF_OPTS(bpf_object_open_opts, open_opts);
> struct core_reloc_test_case *test_case;
> const char *tp_name, *probe_name;
> - int err, i, equal;
> + int err, i, equal, fd;
> struct bpf_link *link = NULL;
> struct bpf_map *data_map;
> struct bpf_program *prog;
> @@ -854,6 +869,7 @@ void test_core_reloc(void)
> my_pid_tgid = getpid() | ((uint64_t)syscall(SYS_gettid) << 32);
>
> for (i = 0; i < ARRAY_SIZE(test_cases); i++) {
> + char btf_file[] = "/tmp/core_reloc.btf.XXXXXX";
> test_case = &test_cases[i];
> if (!test__start_subtest(test_case->case_name))
> continue;
> @@ -863,6 +879,25 @@ void test_core_reloc(void)
> continue;
> }
>
> + /* generate a "minimal" BTF file and use it as source */
> + if (use_btfgen) {
> + if (!test_case->btf_src_file || test_case->fails) {
> + test__skip();
> + continue;
> + }
> +
> + fd = mkstemp(btf_file);
> + if (CHECK(fd < 0, "btf_tmp", "failed to create file: %d\n", fd))
> + goto cleanup;
no new CHECK()s, please
> + close(fd); /* we only need the path */
> + err = run_btfgen(test_case->btf_src_file, btf_file,
> + test_case->bpf_obj_file);
> + if (!ASSERT_OK(err, "run_btfgen"))
> + goto cleanup;
> +
> + test_case->btf_src_file = btf_file;
> + }
> +
> if (test_case->setup) {
> err = test_case->setup(test_case);
> if (CHECK(err, "test_setup", "test #%d setup failed: %d\n", i, err))
> @@ -954,8 +989,19 @@ void test_core_reloc(void)
> CHECK_FAIL(munmap(mmap_data, mmap_sz));
> mmap_data = NULL;
> }
> + remove(btf_file);
would be a bit safer to do unlink() here instead of remove, but it's
probably fine as is (I didn't touch this part)
> bpf_link__destroy(link);
> link = NULL;
> bpf_object__close(obj);
> }
> }
> +
> +void test_core_reloc(void)
> +{
> + run_core_reloc_tests(false);
> +}
> +
> +void test_core_btfgen(void)
> +{
> + run_core_reloc_tests(true);
> +}
> --
> 2.25.1
>
