--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <linux/nsfs.h>
+#include "../kselftest_harness.h"
+#include "../filesystems/utils.h"
+#include "wrappers.h"
+
+/*
+ * Stress tests for namespace active reference counting.
+ *
+ * These tests validate that the active reference counting system can handle
+ * high load scenarios including rapid namespace creation/destruction, large
+ * numbers of concurrent namespaces, and various edge cases under stress.
+ */
+
+/*
+ * Test rapid creation and destruction of user namespaces.
+ * Create and destroy namespaces in quick succession to stress the
+ * active reference tracking and ensure no leaks occur.
+ */
+TEST(rapid_namespace_creation_destruction)
+{
+ struct ns_id_req req = {
+ .size = sizeof(req),
+ .spare = 0,
+ .ns_id = 0,
+ .ns_type = CLONE_NEWUSER,
+ .spare2 = 0,
+ .user_ns_id = 0,
+ };
+ __u64 ns_ids_before[256], ns_ids_after[256];
+ ssize_t ret_before, ret_after;
+ int i;
+
+ /* Get baseline count of active user namespaces */
+ ret_before = sys_listns(&req, ns_ids_before, ARRAY_SIZE(ns_ids_before), 0);
+ if (ret_before < 0) {
+ if (errno == ENOSYS)
+ SKIP(return, "listns() not supported");
+ ASSERT_GE(ret_before, 0);
+ }
+
+ TH_LOG("Baseline: %zd active user namespaces", ret_before);
+
+ /* Rapidly create and destroy 100 user namespaces */
+ for (i = 0; i < 100; i++) {
+ pid_t pid = fork();
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ /* Child: create user namespace and immediately exit */
+ if (setup_userns() < 0)
+ exit(1);
+ exit(0);
+ }
+
+ /* Parent: wait for child */
+ int status;
+ waitpid(pid, &status, 0);
+ ASSERT_TRUE(WIFEXITED(status));
+ ASSERT_EQ(WEXITSTATUS(status), 0);
+ }
+
+ /* Verify we're back to baseline (no leaked namespaces) */
+ ret_after = sys_listns(&req, ns_ids_after, ARRAY_SIZE(ns_ids_after), 0);
+ ASSERT_GE(ret_after, 0);
+
+ TH_LOG("After 100 rapid create/destroy cycles: %zd active user namespaces", ret_after);
+ ASSERT_EQ(ret_before, ret_after);
+}
+
+/*
+ * Test creating many concurrent namespaces.
+ * Verify that listns() correctly tracks all of them and that they all
+ * become inactive after processes exit.
+ */
+TEST(many_concurrent_namespaces)
+{
+ struct ns_id_req req = {
+ .size = sizeof(req),
+ .spare = 0,
+ .ns_id = 0,
+ .ns_type = CLONE_NEWUSER,
+ .spare2 = 0,
+ .user_ns_id = 0,
+ };
+ __u64 ns_ids_before[512], ns_ids_during[512], ns_ids_after[512];
+ ssize_t ret_before, ret_during, ret_after;
+ pid_t pids[50];
+ int num_children = 50;
+ int i;
+ int sv[2];
+
+ /* Get baseline */
+ ret_before = sys_listns(&req, ns_ids_before, ARRAY_SIZE(ns_ids_before), 0);
+ if (ret_before < 0) {
+ if (errno == ENOSYS)
+ SKIP(return, "listns() not supported");
+ ASSERT_GE(ret_before, 0);
+ }
+
+ TH_LOG("Baseline: %zd active user namespaces", ret_before);
+
+ ASSERT_EQ(socketpair(AF_UNIX, SOCK_STREAM, 0, sv), 0);
+
+ /* Create many children, each with their own user namespace */
+ for (i = 0; i < num_children; i++) {
+ pids[i] = fork();
+ ASSERT_GE(pids[i], 0);
+
+ if (pids[i] == 0) {
+ /* Child: create user namespace and wait for parent signal */
+ char c;
+
+ close(sv[0]);
+
+ if (setup_userns() < 0) {
+ close(sv[1]);
+ exit(1);
+ }
+
+ /* Signal parent we're ready */
+ if (write(sv[1], &c, 1) != 1) {
+ close(sv[1]);
+ exit(1);
+ }
+
+ /* Wait for parent signal to exit */
+ if (read(sv[1], &c, 1) != 1) {
+ close(sv[1]);
+ exit(1);
+ }
+
+ close(sv[1]);
+ exit(0);
+ }
+ }
+
+ close(sv[1]);
+
+ /* Wait for all children to signal ready */
+ for (i = 0; i < num_children; i++) {
+ char c;
+ if (read(sv[0], &c, 1) != 1) {
+ /* If we fail to read, kill all children and exit */
+ close(sv[0]);
+ for (int j = 0; j < num_children; j++)
+ kill(pids[j], SIGKILL);
+ for (int j = 0; j < num_children; j++)
+ waitpid(pids[j], NULL, 0);
+ ASSERT_TRUE(false);
+ }
+ }
+
+ /* List namespaces while all children are running */
+ ret_during = sys_listns(&req, ns_ids_during, ARRAY_SIZE(ns_ids_during), 0);
+ ASSERT_GE(ret_during, 0);
+
+ TH_LOG("With %d children running: %zd active user namespaces", num_children, ret_during);
+
+ /* Should have at least num_children more namespaces than baseline */
+ ASSERT_GE(ret_during, ret_before + num_children);
+
+ /* Signal all children to exit */
+ for (i = 0; i < num_children; i++) {
+ char c = 'X';
+ if (write(sv[0], &c, 1) != 1) {
+ /* If we fail to write, kill remaining children */
+ close(sv[0]);
+ for (int j = i; j < num_children; j++)
+ kill(pids[j], SIGKILL);
+ for (int j = 0; j < num_children; j++)
+ waitpid(pids[j], NULL, 0);
+ ASSERT_TRUE(false);
+ }
+ }
+
+ close(sv[0]);
+
+ /* Wait for all children */
+ for (i = 0; i < num_children; i++) {
+ int status;
+ waitpid(pids[i], &status, 0);
+ ASSERT_TRUE(WIFEXITED(status));
+ }
+
+ /* Verify we're back to baseline */
+ ret_after = sys_listns(&req, ns_ids_after, ARRAY_SIZE(ns_ids_after), 0);
+ ASSERT_GE(ret_after, 0);
+
+ TH_LOG("After all children exit: %zd active user namespaces", ret_after);
+ ASSERT_EQ(ret_before, ret_after);
+}
+
+/*
+ * Test rapid namespace creation with different namespace types.
+ * Create multiple types of namespaces rapidly to stress the tracking system.
+ */
+TEST(rapid_mixed_namespace_creation)
+{
+ struct ns_id_req req = {
+ .size = sizeof(req),
+ .spare = 0,
+ .ns_id = 0,
+ .ns_type = 0, /* All types */
+ .spare2 = 0,
+ .user_ns_id = 0,
+ };
+ __u64 ns_ids_before[512], ns_ids_after[512];
+ ssize_t ret_before, ret_after;
+ int i;
+
+ /* Get baseline count */
+ ret_before = sys_listns(&req, ns_ids_before, ARRAY_SIZE(ns_ids_before), 0);
+ if (ret_before < 0) {
+ if (errno == ENOSYS)
+ SKIP(return, "listns() not supported");
+ ASSERT_GE(ret_before, 0);
+ }
+
+ TH_LOG("Baseline: %zd active namespaces (all types)", ret_before);
+
+ /* Rapidly create and destroy namespaces with multiple types */
+ for (i = 0; i < 50; i++) {
+ pid_t pid = fork();
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ /* Child: create multiple namespace types */
+ if (setup_userns() < 0)
+ exit(1);
+
+ /* Create additional namespace types */
+ if (unshare(CLONE_NEWNET) < 0)
+ exit(1);
+ if (unshare(CLONE_NEWUTS) < 0)
+ exit(1);
+ if (unshare(CLONE_NEWIPC) < 0)
+ exit(1);
+
+ exit(0);
+ }
+
+ /* Parent: wait for child */
+ int status;
+ waitpid(pid, &status, 0);
+ ASSERT_TRUE(WIFEXITED(status));
+ }
+
+ /* Verify we're back to baseline */
+ ret_after = sys_listns(&req, ns_ids_after, ARRAY_SIZE(ns_ids_after), 0);
+ ASSERT_GE(ret_after, 0);
+
+ TH_LOG("After 50 rapid mixed namespace cycles: %zd active namespaces", ret_after);
+ ASSERT_EQ(ret_before, ret_after);
+}
+
+/*
+ * Test nested namespace creation under stress.
+ * Create deeply nested namespace hierarchies and verify proper cleanup.
+ */
+TEST(nested_namespace_stress)
+{
+ struct ns_id_req req = {
+ .size = sizeof(req),
+ .spare = 0,
+ .ns_id = 0,
+ .ns_type = CLONE_NEWUSER,
+ .spare2 = 0,
+ .user_ns_id = 0,
+ };
+ __u64 ns_ids_before[512], ns_ids_after[512];
+ ssize_t ret_before, ret_after;
+ int i;
+
+ /* Get baseline */
+ ret_before = sys_listns(&req, ns_ids_before, ARRAY_SIZE(ns_ids_before), 0);
+ if (ret_before < 0) {
+ if (errno == ENOSYS)
+ SKIP(return, "listns() not supported");
+ ASSERT_GE(ret_before, 0);
+ }
+
+ TH_LOG("Baseline: %zd active user namespaces", ret_before);
+
+ /* Create 20 processes, each with nested user namespaces */
+ for (i = 0; i < 20; i++) {
+ pid_t pid = fork();
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ int userns_fd;
+ uid_t orig_uid = getuid();
+ int depth;
+
+ /* Create nested user namespaces (up to 5 levels) */
+ for (depth = 0; depth < 5; depth++) {
+ userns_fd = get_userns_fd(0, (depth == 0) ? orig_uid : 0, 1);
+ if (userns_fd < 0)
+ exit(1);
+
+ if (setns(userns_fd, CLONE_NEWUSER) < 0) {
+ close(userns_fd);
+ exit(1);
+ }
+ close(userns_fd);
+ }
+
+ exit(0);
+ }
+
+ /* Parent: wait for child */
+ int status;
+ waitpid(pid, &status, 0);
+ ASSERT_TRUE(WIFEXITED(status));
+ }
+
+ /* Verify we're back to baseline */
+ ret_after = sys_listns(&req, ns_ids_after, ARRAY_SIZE(ns_ids_after), 0);
+ ASSERT_GE(ret_after, 0);
+
+ TH_LOG("After 20 nested namespace hierarchies: %zd active user namespaces", ret_after);
+ ASSERT_EQ(ret_before, ret_after);
+}
+
+/*
+ * Test listns() pagination under stress.
+ * Create many namespaces and verify pagination works correctly.
+ */
+TEST(listns_pagination_stress)
+{
+ struct ns_id_req req = {
+ .size = sizeof(req),
+ .spare = 0,
+ .ns_id = 0,
+ .ns_type = CLONE_NEWUSER,
+ .spare2 = 0,
+ .user_ns_id = 0,
+ };
+ pid_t pids[30];
+ int num_children = 30;
+ int i;
+ int sv[2];
+ __u64 all_ns_ids[512];
+ int total_found = 0;
+
+ ASSERT_EQ(socketpair(AF_UNIX, SOCK_STREAM, 0, sv), 0);
+
+ /* Create many children with user namespaces */
+ for (i = 0; i < num_children; i++) {
+ pids[i] = fork();
+ ASSERT_GE(pids[i], 0);
+
+ if (pids[i] == 0) {
+ char c;
+ close(sv[0]);
+
+ if (setup_userns() < 0) {
+ close(sv[1]);
+ exit(1);
+ }
+
+ /* Signal parent we're ready */
+ if (write(sv[1], &c, 1) != 1) {
+ close(sv[1]);
+ exit(1);
+ }
+
+ /* Wait for parent signal to exit */
+ if (read(sv[1], &c, 1) != 1) {
+ close(sv[1]);
+ exit(1);
+ }
+
+ close(sv[1]);
+ exit(0);
+ }
+ }
+
+ close(sv[1]);
+
+ /* Wait for all children to signal ready */
+ for (i = 0; i < num_children; i++) {
+ char c;
+ if (read(sv[0], &c, 1) != 1) {
+ /* If we fail to read, kill all children and exit */
+ close(sv[0]);
+ for (int j = 0; j < num_children; j++)
+ kill(pids[j], SIGKILL);
+ for (int j = 0; j < num_children; j++)
+ waitpid(pids[j], NULL, 0);
+ ASSERT_TRUE(false);
+ }
+ }
+
+ /* Paginate through all namespaces using small batch sizes */
+ req.ns_id = 0;
+ while (1) {
+ __u64 batch[5]; /* Small batch size to force pagination */
+ ssize_t ret;
+
+ ret = sys_listns(&req, batch, ARRAY_SIZE(batch), 0);
+ if (ret < 0) {
+ if (errno == ENOSYS) {
+ close(sv[0]);
+ for (i = 0; i < num_children; i++)
+ kill(pids[i], SIGKILL);
+ for (i = 0; i < num_children; i++)
+ waitpid(pids[i], NULL, 0);
+ SKIP(return, "listns() not supported");
+ }
+ ASSERT_GE(ret, 0);
+ }
+
+ if (ret == 0)
+ break;
+
+ /* Store results */
+ for (i = 0; i < ret && total_found < 512; i++) {
+ all_ns_ids[total_found++] = batch[i];
+ }
+
+ /* Update cursor for next batch */
+ if (ret == ARRAY_SIZE(batch))
+ req.ns_id = batch[ret - 1];
+ else
+ break;
+ }
+
+ TH_LOG("Paginated through %d user namespaces", total_found);
+
+ /* Verify no duplicates in pagination */
+ for (i = 0; i < total_found; i++) {
+ for (int j = i + 1; j < total_found; j++) {
+ if (all_ns_ids[i] == all_ns_ids[j]) {
+ TH_LOG("Found duplicate ns_id: %llu at positions %d and %d",
+ (unsigned long long)all_ns_ids[i], i, j);
+ ASSERT_TRUE(false);
+ }
+ }
+ }
+
+ /* Signal all children to exit */
+ for (i = 0; i < num_children; i++) {
+ char c = 'X';
+ if (write(sv[0], &c, 1) != 1) {
+ close(sv[0]);
+ for (int j = i; j < num_children; j++)
+ kill(pids[j], SIGKILL);
+ for (int j = 0; j < num_children; j++)
+ waitpid(pids[j], NULL, 0);
+ ASSERT_TRUE(false);
+ }
+ }
+
+ close(sv[0]);
+
+ /* Wait for all children */
+ for (i = 0; i < num_children; i++) {
+ int status;
+ waitpid(pids[i], &status, 0);
+ }
+}
+
+/*
+ * Test concurrent namespace operations.
+ * Multiple processes creating, querying, and destroying namespaces concurrently.
+ */
+TEST(concurrent_namespace_operations)
+{
+ struct ns_id_req req = {
+ .size = sizeof(req),
+ .spare = 0,
+ .ns_id = 0,
+ .ns_type = 0,
+ .spare2 = 0,
+ .user_ns_id = 0,
+ };
+ __u64 ns_ids_before[512], ns_ids_after[512];
+ ssize_t ret_before, ret_after;
+ pid_t pids[20];
+ int num_workers = 20;
+ int i;
+
+ /* Get baseline */
+ ret_before = sys_listns(&req, ns_ids_before, ARRAY_SIZE(ns_ids_before), 0);
+ if (ret_before < 0) {
+ if (errno == ENOSYS)
+ SKIP(return, "listns() not supported");
+ ASSERT_GE(ret_before, 0);
+ }
+
+ TH_LOG("Baseline: %zd active namespaces", ret_before);
+
+ /* Create worker processes that do concurrent operations */
+ for (i = 0; i < num_workers; i++) {
+ pids[i] = fork();
+ ASSERT_GE(pids[i], 0);
+
+ if (pids[i] == 0) {
+ /* Each worker: create namespaces, list them, repeat */
+ int iterations;
+
+ for (iterations = 0; iterations < 10; iterations++) {
+ int userns_fd;
+ __u64 temp_ns_ids[100];
+ ssize_t ret;
+
+ /* Create a user namespace */
+ userns_fd = get_userns_fd(0, getuid(), 1);
+ if (userns_fd < 0)
+ continue;
+
+ /* List namespaces */
+ ret = sys_listns(&req, temp_ns_ids, ARRAY_SIZE(temp_ns_ids), 0);
+ (void)ret;
+
+ close(userns_fd);
+
+ /* Small delay */
+ usleep(1000);
+ }
+
+ exit(0);
+ }
+ }
+
+ /* Wait for all workers */
+ for (i = 0; i < num_workers; i++) {
+ int status;
+ waitpid(pids[i], &status, 0);
+ ASSERT_TRUE(WIFEXITED(status));
+ ASSERT_EQ(WEXITSTATUS(status), 0);
+ }
+
+ /* Verify we're back to baseline */
+ ret_after = sys_listns(&req, ns_ids_after, ARRAY_SIZE(ns_ids_after), 0);
+ ASSERT_GE(ret_after, 0);
+
+ TH_LOG("After concurrent operations: %zd active namespaces", ret_after);
+ ASSERT_EQ(ret_before, ret_after);
+}
+
+/*
+ * Test namespace churn - continuous creation and destruction.
+ * Simulates high-churn scenarios like container orchestration.
+ */
+TEST(namespace_churn)
+{
+ struct ns_id_req req = {
+ .size = sizeof(req),
+ .spare = 0,
+ .ns_id = 0,
+ .ns_type = CLONE_NEWUSER | CLONE_NEWNET | CLONE_NEWUTS,
+ .spare2 = 0,
+ .user_ns_id = 0,
+ };
+ __u64 ns_ids_before[512], ns_ids_after[512];
+ ssize_t ret_before, ret_after;
+ int cycle;
+
+ /* Get baseline */
+ ret_before = sys_listns(&req, ns_ids_before, ARRAY_SIZE(ns_ids_before), 0);
+ if (ret_before < 0) {
+ if (errno == ENOSYS)
+ SKIP(return, "listns() not supported");
+ ASSERT_GE(ret_before, 0);
+ }
+
+ TH_LOG("Baseline: %zd active namespaces", ret_before);
+
+ /* Simulate churn: batches of namespaces created and destroyed */
+ for (cycle = 0; cycle < 10; cycle++) {
+ pid_t batch_pids[10];
+ int i;
+
+ /* Create batch */
+ for (i = 0; i < 10; i++) {
+ batch_pids[i] = fork();
+ ASSERT_GE(batch_pids[i], 0);
+
+ if (batch_pids[i] == 0) {
+ /* Create multiple namespace types */
+ if (setup_userns() < 0)
+ exit(1);
+ if (unshare(CLONE_NEWNET) < 0)
+ exit(1);
+ if (unshare(CLONE_NEWUTS) < 0)
+ exit(1);
+
+ /* Keep namespaces alive briefly */
+ usleep(10000);
+ exit(0);
+ }
+ }
+
+ /* Wait for batch to complete */
+ for (i = 0; i < 10; i++) {
+ int status;
+ waitpid(batch_pids[i], &status, 0);
+ }
+ }
+
+ /* Verify we're back to baseline */
+ ret_after = sys_listns(&req, ns_ids_after, ARRAY_SIZE(ns_ids_after), 0);
+ ASSERT_GE(ret_after, 0);
+
+ TH_LOG("After 10 churn cycles (100 namespace sets): %zd active namespaces", ret_after);
+ ASSERT_EQ(ret_before, ret_after);
+}
+
+TEST_HARNESS_MAIN
projects / thirdparty / linux.git / commitdiff
