linux/tools/testing/selftests/namespaces/stress_test.c

627 lines
14 KiB
C

// 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