1 files changed, 126 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/htab_update.c b/tools/testing/selftests/bpf/prog_tests/htab_update.c
new file mode 100644
index 000000000000..2bc85f4814f4
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/htab_update.c
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2022. Huawei Technologies Co., Ltd */
+#define _GNU_SOURCE
+#include <sched.h>
+#include <stdbool.h>
+#include <test_progs.h>
+#include "htab_update.skel.h"
+
+struct htab_update_ctx {
+	int fd;
+	int loop;
+	bool stop;
+};
+
+static void test_reenter_update(void)
+{
+	struct htab_update *skel;
+	unsigned int key, value;
+	int err;
+
+	skel = htab_update__open();
+	if (!ASSERT_OK_PTR(skel, "htab_update__open"))
+		return;
+
+	/* lookup_elem_raw() may be inlined and find_kernel_btf_id() will return -ESRCH */
+	bpf_program__set_autoload(skel->progs.lookup_elem_raw, true);
+	err = htab_update__load(skel);
+	if (!ASSERT_TRUE(!err || err == -ESRCH, "htab_update__load") || err)
+		goto out;
+
+	skel->bss->pid = getpid();
+	err = htab_update__attach(skel);
+	if (!ASSERT_OK(err, "htab_update__attach"))
+		goto out;
+
+	/* Will trigger the reentrancy of bpf_map_update_elem() */
+	key = 0;
+	value = 0;
+	err = bpf_map_update_elem(bpf_map__fd(skel->maps.htab), &key, &value, 0);
+	if (!ASSERT_OK(err, "add element"))
+		goto out;
+
+	ASSERT_EQ(skel->bss->update_err, -EBUSY, "no reentrancy");
+out:
+	htab_update__destroy(skel);
+}
+
+static void *htab_update_thread(void *arg)
+{
+	struct htab_update_ctx *ctx = arg;
+	cpu_set_t cpus;
+	int i;
+
+	/* Pinned on CPU 0 */
+	CPU_ZERO(&cpus);
+	CPU_SET(0, &cpus);
+	pthread_setaffinity_np(pthread_self(), sizeof(cpus), &cpus);
+
+	i = 0;
+	while (i++ < ctx->loop && !ctx->stop) {
+		unsigned int key = 0, value = 0;
+		int err;
+
+		err = bpf_map_update_elem(ctx->fd, &key, &value, 0);
+		if (err) {
+			ctx->stop = true;
+			return (void *)(long)err;
+		}
+	}
+
+	return NULL;
+}
+
+static void test_concurrent_update(void)
+{
+	struct htab_update_ctx ctx;
+	struct htab_update *skel;
+	unsigned int i, nr;
+	pthread_t *tids;
+	int err;
+
+	skel = htab_update__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "htab_update__open_and_load"))
+		return;
+
+	ctx.fd = bpf_map__fd(skel->maps.htab);
+	ctx.loop = 1000;
+	ctx.stop = false;
+
+	nr = 4;
+	tids = calloc(nr, sizeof(*tids));
+	if (!ASSERT_NEQ(tids, NULL, "no mem"))
+		goto out;
+
+	for (i = 0; i < nr; i++) {
+		err = pthread_create(&tids[i], NULL, htab_update_thread, &ctx);
+		if (!ASSERT_OK(err, "pthread_create")) {
+			unsigned int j;
+
+			ctx.stop = true;
+			for (j = 0; j < i; j++)
+				pthread_join(tids[j], NULL);
+			goto out;
+		}
+	}
+
+	for (i = 0; i < nr; i++) {
+		void *thread_err = NULL;
+
+		pthread_join(tids[i], &thread_err);
+		ASSERT_EQ(thread_err, NULL, "update error");
+	}
+
+out:
+	if (tids)
+		free(tids);
+	htab_update__destroy(skel);
+}
+
+void test_htab_update(void)
+{
+	if (test__start_subtest("reenter_update"))
+		test_reenter_update();
+	if (test__start_subtest("concurrent_update"))
+		test_concurrent_update();
+}