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-rw-r--r--tools/testing/selftests/cgroup/test_core.c342
1 files changed, 342 insertions, 0 deletions
diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c
index e19ce940cd6a..600123503063 100644
--- a/tools/testing/selftests/cgroup/test_core.c
+++ b/tools/testing/selftests/cgroup/test_core.c
@@ -1,8 +1,14 @@
/* SPDX-License-Identifier: GPL-2.0 */
+#define _GNU_SOURCE
#include <linux/limits.h>
+#include <linux/sched.h>
#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/wait.h>
#include <unistd.h>
+#include <fcntl.h>
+#include <sched.h>
#include <stdio.h>
#include <errno.h>
#include <signal.h>
@@ -12,6 +18,115 @@
#include "../kselftest.h"
#include "cgroup_util.h"
+static int touch_anon(char *buf, size_t size)
+{
+ int fd;
+ char *pos = buf;
+
+ fd = open("/dev/urandom", O_RDONLY);
+ if (fd < 0)
+ return -1;
+
+ while (size > 0) {
+ ssize_t ret = read(fd, pos, size);
+
+ if (ret < 0) {
+ if (errno != EINTR) {
+ close(fd);
+ return -1;
+ }
+ } else {
+ pos += ret;
+ size -= ret;
+ }
+ }
+ close(fd);
+
+ return 0;
+}
+
+static int alloc_and_touch_anon_noexit(const char *cgroup, void *arg)
+{
+ int ppid = getppid();
+ size_t size = (size_t)arg;
+ void *buf;
+
+ buf = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON,
+ 0, 0);
+ if (buf == MAP_FAILED)
+ return -1;
+
+ if (touch_anon((char *)buf, size)) {
+ munmap(buf, size);
+ return -1;
+ }
+
+ while (getppid() == ppid)
+ sleep(1);
+
+ munmap(buf, size);
+ return 0;
+}
+
+/*
+ * Create a child process that allocates and touches 100MB, then waits to be
+ * killed. Wait until the child is attached to the cgroup, kill all processes
+ * in that cgroup and wait until "cgroup.procs" is empty. At this point try to
+ * destroy the empty cgroup. The test helps detect race conditions between
+ * dying processes leaving the cgroup and cgroup destruction path.
+ */
+static int test_cgcore_destroy(const char *root)
+{
+ int ret = KSFT_FAIL;
+ char *cg_test = NULL;
+ int child_pid;
+ char buf[PAGE_SIZE];
+
+ cg_test = cg_name(root, "cg_test");
+
+ if (!cg_test)
+ goto cleanup;
+
+ for (int i = 0; i < 10; i++) {
+ if (cg_create(cg_test))
+ goto cleanup;
+
+ child_pid = cg_run_nowait(cg_test, alloc_and_touch_anon_noexit,
+ (void *) MB(100));
+
+ if (child_pid < 0)
+ goto cleanup;
+
+ /* wait for the child to enter cgroup */
+ if (cg_wait_for_proc_count(cg_test, 1))
+ goto cleanup;
+
+ if (cg_killall(cg_test))
+ goto cleanup;
+
+ /* wait for cgroup to be empty */
+ while (1) {
+ if (cg_read(cg_test, "cgroup.procs", buf, sizeof(buf)))
+ goto cleanup;
+ if (buf[0] == '\0')
+ break;
+ usleep(1000);
+ }
+
+ if (rmdir(cg_test))
+ goto cleanup;
+
+ if (waitpid(child_pid, NULL, 0) < 0)
+ goto cleanup;
+ }
+ ret = KSFT_PASS;
+cleanup:
+ if (cg_test)
+ cg_destroy(cg_test);
+ free(cg_test);
+ return ret;
+}
+
/*
* A(0) - B(0) - C(1)
* \ D(0)
@@ -25,8 +140,11 @@
static int test_cgcore_populated(const char *root)
{
int ret = KSFT_FAIL;
+ int err;
char *cg_test_a = NULL, *cg_test_b = NULL;
char *cg_test_c = NULL, *cg_test_d = NULL;
+ int cgroup_fd = -EBADF;
+ pid_t pid;
cg_test_a = cg_name(root, "cg_test_a");
cg_test_b = cg_name(root, "cg_test_a/cg_test_b");
@@ -78,6 +196,52 @@ static int test_cgcore_populated(const char *root)
if (cg_read_strcmp(cg_test_d, "cgroup.events", "populated 0\n"))
goto cleanup;
+ /* Test that we can directly clone into a new cgroup. */
+ cgroup_fd = dirfd_open_opath(cg_test_d);
+ if (cgroup_fd < 0)
+ goto cleanup;
+
+ pid = clone_into_cgroup(cgroup_fd);
+ if (pid < 0) {
+ if (errno == ENOSYS)
+ goto cleanup_pass;
+ goto cleanup;
+ }
+
+ if (pid == 0) {
+ if (raise(SIGSTOP))
+ exit(EXIT_FAILURE);
+ exit(EXIT_SUCCESS);
+ }
+
+ err = cg_read_strcmp(cg_test_d, "cgroup.events", "populated 1\n");
+
+ (void)clone_reap(pid, WSTOPPED);
+ (void)kill(pid, SIGCONT);
+ (void)clone_reap(pid, WEXITED);
+
+ if (err)
+ goto cleanup;
+
+ if (cg_read_strcmp(cg_test_d, "cgroup.events", "populated 0\n"))
+ goto cleanup;
+
+ /* Remove cgroup. */
+ if (cg_test_d) {
+ cg_destroy(cg_test_d);
+ free(cg_test_d);
+ cg_test_d = NULL;
+ }
+
+ pid = clone_into_cgroup(cgroup_fd);
+ if (pid < 0)
+ goto cleanup_pass;
+ if (pid == 0)
+ exit(EXIT_SUCCESS);
+ (void)clone_reap(pid, WEXITED);
+ goto cleanup;
+
+cleanup_pass:
ret = KSFT_PASS;
cleanup:
@@ -93,6 +257,8 @@ cleanup:
free(cg_test_c);
free(cg_test_b);
free(cg_test_a);
+ if (cgroup_fd >= 0)
+ close(cgroup_fd);
return ret;
}
@@ -136,6 +302,16 @@ static int test_cgcore_invalid_domain(const char *root)
if (errno != EOPNOTSUPP)
goto cleanup;
+ if (!clone_into_cgroup_run_wait(child))
+ goto cleanup;
+
+ if (errno == ENOSYS)
+ goto cleanup_pass;
+
+ if (errno != EOPNOTSUPP)
+ goto cleanup;
+
+cleanup_pass:
ret = KSFT_PASS;
cleanup:
@@ -345,6 +521,9 @@ static int test_cgcore_internal_process_constraint(const char *root)
if (!cg_enter_current(parent))
goto cleanup;
+ if (!clone_into_cgroup_run_wait(parent))
+ goto cleanup;
+
ret = KSFT_PASS;
cleanup:
@@ -498,6 +677,166 @@ cleanup:
return ret;
}
+/*
+ * cgroup migration permission check should be performed based on the
+ * credentials at the time of open instead of write.
+ */
+static int test_cgcore_lesser_euid_open(const char *root)
+{
+ const uid_t test_euid = 65534; /* usually nobody, any !root is fine */
+ int ret = KSFT_FAIL;
+ char *cg_test_a = NULL, *cg_test_b = NULL;
+ char *cg_test_a_procs = NULL, *cg_test_b_procs = NULL;
+ int cg_test_b_procs_fd = -1;
+ uid_t saved_uid;
+
+ cg_test_a = cg_name(root, "cg_test_a");
+ cg_test_b = cg_name(root, "cg_test_b");
+
+ if (!cg_test_a || !cg_test_b)
+ goto cleanup;
+
+ cg_test_a_procs = cg_name(cg_test_a, "cgroup.procs");
+ cg_test_b_procs = cg_name(cg_test_b, "cgroup.procs");
+
+ if (!cg_test_a_procs || !cg_test_b_procs)
+ goto cleanup;
+
+ if (cg_create(cg_test_a) || cg_create(cg_test_b))
+ goto cleanup;
+
+ if (cg_enter_current(cg_test_a))
+ goto cleanup;
+
+ if (chown(cg_test_a_procs, test_euid, -1) ||
+ chown(cg_test_b_procs, test_euid, -1))
+ goto cleanup;
+
+ saved_uid = geteuid();
+ if (seteuid(test_euid))
+ goto cleanup;
+
+ cg_test_b_procs_fd = open(cg_test_b_procs, O_RDWR);
+
+ if (seteuid(saved_uid))
+ goto cleanup;
+
+ if (cg_test_b_procs_fd < 0)
+ goto cleanup;
+
+ if (write(cg_test_b_procs_fd, "0", 1) >= 0 || errno != EACCES)
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ cg_enter_current(root);
+ if (cg_test_b_procs_fd >= 0)
+ close(cg_test_b_procs_fd);
+ if (cg_test_b)
+ cg_destroy(cg_test_b);
+ if (cg_test_a)
+ cg_destroy(cg_test_a);
+ free(cg_test_b_procs);
+ free(cg_test_a_procs);
+ free(cg_test_b);
+ free(cg_test_a);
+ return ret;
+}
+
+struct lesser_ns_open_thread_arg {
+ const char *path;
+ int fd;
+ int err;
+};
+
+static int lesser_ns_open_thread_fn(void *arg)
+{
+ struct lesser_ns_open_thread_arg *targ = arg;
+
+ targ->fd = open(targ->path, O_RDWR);
+ targ->err = errno;
+ return 0;
+}
+
+/*
+ * cgroup migration permission check should be performed based on the cgroup
+ * namespace at the time of open instead of write.
+ */
+static int test_cgcore_lesser_ns_open(const char *root)
+{
+ static char stack[65536];
+ const uid_t test_euid = 65534; /* usually nobody, any !root is fine */
+ int ret = KSFT_FAIL;
+ char *cg_test_a = NULL, *cg_test_b = NULL;
+ char *cg_test_a_procs = NULL, *cg_test_b_procs = NULL;
+ int cg_test_b_procs_fd = -1;
+ struct lesser_ns_open_thread_arg targ = { .fd = -1 };
+ pid_t pid;
+ int status;
+
+ cg_test_a = cg_name(root, "cg_test_a");
+ cg_test_b = cg_name(root, "cg_test_b");
+
+ if (!cg_test_a || !cg_test_b)
+ goto cleanup;
+
+ cg_test_a_procs = cg_name(cg_test_a, "cgroup.procs");
+ cg_test_b_procs = cg_name(cg_test_b, "cgroup.procs");
+
+ if (!cg_test_a_procs || !cg_test_b_procs)
+ goto cleanup;
+
+ if (cg_create(cg_test_a) || cg_create(cg_test_b))
+ goto cleanup;
+
+ if (cg_enter_current(cg_test_b))
+ goto cleanup;
+
+ if (chown(cg_test_a_procs, test_euid, -1) ||
+ chown(cg_test_b_procs, test_euid, -1))
+ goto cleanup;
+
+ targ.path = cg_test_b_procs;
+ pid = clone(lesser_ns_open_thread_fn, stack + sizeof(stack),
+ CLONE_NEWCGROUP | CLONE_FILES | CLONE_VM | SIGCHLD,
+ &targ);
+ if (pid < 0)
+ goto cleanup;
+
+ if (waitpid(pid, &status, 0) < 0)
+ goto cleanup;
+
+ if (!WIFEXITED(status))
+ goto cleanup;
+
+ cg_test_b_procs_fd = targ.fd;
+ if (cg_test_b_procs_fd < 0)
+ goto cleanup;
+
+ if (cg_enter_current(cg_test_a))
+ goto cleanup;
+
+ if ((status = write(cg_test_b_procs_fd, "0", 1)) >= 0 || errno != ENOENT)
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ cg_enter_current(root);
+ if (cg_test_b_procs_fd >= 0)
+ close(cg_test_b_procs_fd);
+ if (cg_test_b)
+ cg_destroy(cg_test_b);
+ if (cg_test_a)
+ cg_destroy(cg_test_a);
+ free(cg_test_b_procs);
+ free(cg_test_a_procs);
+ free(cg_test_b);
+ free(cg_test_a);
+ return ret;
+}
+
#define T(x) { x, #x }
struct corecg_test {
int (*fn)(const char *root);
@@ -512,6 +851,9 @@ struct corecg_test {
T(test_cgcore_populated),
T(test_cgcore_proc_migration),
T(test_cgcore_thread_migration),
+ T(test_cgcore_destroy),
+ T(test_cgcore_lesser_euid_open),
+ T(test_cgcore_lesser_ns_open),
};
#undef T
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.