When a test process is not able to write to TH_LOG_STREAM, this step mechanism enable to print the assert number which triggered the failure. This can be enabled by setting _metadata->no_print to true at the beginning of the test sequence. Update the seccomp-bpf test to return 0 if a test succeeded. This feature is needed for the Landlock tests. Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Cc: Will Drewry <wad@xxxxxxxxxxxx> Link: https://lkml.kernel.org/r/CAGXu5j+D-FP8Kt9unNOqKrQJP4DYTpmgkJxWykZyrYiVPz3Y3Q@xxxxxxxxxxxxxx --- Changes since the patch from the Landlock series: * add the step counter in assert/expect macros and use _metadata to enable the counter (suggested by Kees Cook) * only count asserts * add documentation --- tools/testing/selftests/kselftest_harness.h | 39 +++++++++++++++++++++++---- tools/testing/selftests/seccomp/seccomp_bpf.c | 2 +- 2 files changed, 35 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h index c56f72e07cd7..e81bd28bdd89 100644 --- a/tools/testing/selftests/kselftest_harness.h +++ b/tools/testing/selftests/kselftest_harness.h @@ -51,6 +51,9 @@ #define __KSELFTEST_HARNESS_H #define _GNU_SOURCE +#include <asm/types.h> +#include <errno.h> +#include <stdbool.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> @@ -84,6 +87,14 @@ * E.g., #define TH_LOG_ENABLED 1 * * If no definition is provided, logging is enabled by default. + * + * If there is no way to print an error message for the process running the + * test (e.g. not allowed to write to stderr), it is still possible to get the + * ASSERT_* number for which the test failed. This behavior can be enabled by + * writing `_metadata->no_print = true;` before the check sequence that is + * unable to print. When an error occur, instead of printing an error message + * and calling `abort(3)`, the test process call `_exit(2)` with the assert + * number as argument, which is then printed by the parent process. */ #define TH_LOG(fmt, ...) do { \ if (TH_LOG_ENABLED) \ @@ -555,12 +566,18 @@ * return while still providing an optional block to the API consumer. */ #define OPTIONAL_HANDLER(_assert) \ - for (; _metadata->trigger; _metadata->trigger = __bail(_assert)) + for (; _metadata->trigger; _metadata->trigger = \ + __bail(_assert, _metadata->no_print, _metadata->step)) + +#define __INC_STEP(_metadata) \ + if (_metadata->passed && _metadata->step < 255) \ + _metadata->step++; #define __EXPECT(_expected, _seen, _t, _assert) do { \ /* Avoid multiple evaluation of the cases */ \ __typeof__(_expected) __exp = (_expected); \ __typeof__(_seen) __seen = (_seen); \ + if (_assert) __INC_STEP(_metadata); \ if (!(__exp _t __seen)) { \ unsigned long long __exp_print = (uintptr_t)__exp; \ unsigned long long __seen_print = (uintptr_t)__seen; \ @@ -576,6 +593,7 @@ #define __EXPECT_STR(_expected, _seen, _t, _assert) do { \ const char *__exp = (_expected); \ const char *__seen = (_seen); \ + if (_assert) __INC_STEP(_metadata); \ if (!(strcmp(__exp, __seen) _t 0)) { \ __TH_LOG("Expected '%s' %s '%s'.", __exp, #_t, __seen); \ _metadata->passed = 0; \ @@ -590,6 +608,8 @@ struct __test_metadata { int termsig; int passed; int trigger; /* extra handler after the evaluation */ + __u8 step; + bool no_print; /* manual trigger when TH_LOG_STREAM is not available */ struct __test_metadata *prev, *next; }; @@ -634,10 +654,13 @@ static inline void __register_test(struct __test_metadata *t) } } -static inline int __bail(int for_realz) +static inline int __bail(int for_realz, bool no_print, __u8 step) { - if (for_realz) + if (for_realz) { + if (no_print) + _exit(step); abort(); + } return 0; } @@ -655,18 +678,24 @@ void __run_test(struct __test_metadata *t) t->passed = 0; } else if (child_pid == 0) { t->fn(t); - _exit(t->passed); + /* return the step that failed or 0 */ + _exit(t->passed ? 0 : t->step); } else { /* TODO(wad) add timeout support. */ waitpid(child_pid, &status, 0); if (WIFEXITED(status)) { - t->passed = t->termsig == -1 ? WEXITSTATUS(status) : 0; + t->passed = t->termsig == -1 ? !WEXITSTATUS(status) : 0; if (t->termsig != -1) { fprintf(TH_LOG_STREAM, "%s: Test exited normally " "instead of by signal (code: %d)\n", t->name, WEXITSTATUS(status)); + } else if (!t->passed) { + fprintf(TH_LOG_STREAM, + "%s: Test failed at step #%d\n", + t->name, + WEXITSTATUS(status)); } } else if (WIFSIGNALED(status)) { t->passed = 0; diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index 73f5ea6778ce..4d6f92a9df6b 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -107,7 +107,7 @@ TEST(mode_strict_support) ASSERT_EQ(0, ret) { TH_LOG("Kernel does not support CONFIG_SECCOMP"); } - syscall(__NR_exit, 1); + syscall(__NR_exit, 0); } TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL) -- 2.13.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
