selftests/bpf: Reset process and thread affinity after each test/sub-test

Some tests and sub-tests are setting "custom" thread/process affinity and
don't reset it back. Instead of requiring each test to undo all this, ensure
that thread affinity is restored by test_progs test runner itself.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200314013932.4035712-3-andriin@fb.com

diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index c8cb407..b521e0a 100644 (file)
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -1,12 +1,15 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2017 Facebook
  */
+#define _GNU_SOURCE
 #include "test_progs.h"
 #include "cgroup_helpers.h"
 #include "bpf_rlimit.h"
 #include <argp.h>
-#include <string.h>
+#include <pthread.h>
+#include <sched.h>
 #include <signal.h>
+#include <string.h>
 #include <execinfo.h> /* backtrace */
 
 /* defined in test_progs.h */
@@ -90,6 +93,34 @@ static void skip_account(void)
        }
 }
 
+static void stdio_restore(void);
+
+/* A bunch of tests set custom affinity per-thread and/or per-process. Reset
+ * it after each test/sub-test.
+ */
+static void reset_affinity() {
+
+       cpu_set_t cpuset;
+       int i, err;
+
+       CPU_ZERO(&cpuset);
+       for (i = 0; i < env.nr_cpus; i++)
+               CPU_SET(i, &cpuset);
+
+       err = sched_setaffinity(0, sizeof(cpuset), &cpuset);
+       if (err < 0) {
+               stdio_restore();
+               fprintf(stderr, "Failed to reset process affinity: %d!\n", err);
+               exit(-1);
+       }
+       err = pthread_setaffinity_np(pthread_self(), sizeof(cpuset), &cpuset);
+       if (err < 0) {
+               stdio_restore();
+               fprintf(stderr, "Failed to reset thread affinity: %d!\n", err);
+               exit(-1);
+       }
+}
+
 void test__end_subtest()
 {
        struct prog_test_def *test = env.test;
@@ -107,6 +138,8 @@ void test__end_subtest()
               test->test_num, test->subtest_num,
               test->subtest_name, sub_error_cnt ? "FAIL" : "OK");
 
+       reset_affinity();
+
        free(test->subtest_name);
        test->subtest_name = NULL;
 }
@@ -679,6 +712,12 @@ int main(int argc, char **argv)
        srand(time(NULL));
 
        env.jit_enabled = is_jit_enabled();
+       env.nr_cpus = libbpf_num_possible_cpus();
+       if (env.nr_cpus < 0) {
+               fprintf(stderr, "Failed to get number of CPUs: %d!\n",
+                       env.nr_cpus);
+               return -1;
+       }
 
        stdio_hijack();
        for (i = 0; i < prog_test_cnt; i++) {
@@ -709,6 +748,7 @@ int main(int argc, char **argv)
                        test->test_num, test->test_name,
                        test->error_cnt ? "FAIL" : "OK");
 
+               reset_affinity();
                if (test->need_cgroup_cleanup)
                        cleanup_cgroup_environment();
        }

diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h
index fd85fa6..f4aff6b 100644 (file)
--- a/tools/testing/selftests/bpf/test_progs.h
+++ b/tools/testing/selftests/bpf/test_progs.h
@@ -71,6 +71,7 @@ struct test_env {
        FILE *stderr;
        char *log_buf;
        size_t log_cnt;
+       int nr_cpus;
 
        int succ_cnt; /* successful tests */
        int sub_succ_cnt; /* successful sub-tests */