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-rw-r--r--tools/testing/selftests/pidfd/.gitignore7
-rw-r--r--tools/testing/selftests/pidfd/Makefile8
-rw-r--r--tools/testing/selftests/pidfd/config1
-rw-r--r--tools/testing/selftests/pidfd/pidfd.h210
-rw-r--r--tools/testing/selftests/pidfd/pidfd_autoreap_test.c900
-rw-r--r--tools/testing/selftests/pidfd/pidfd_bind_mount.c116
-rw-r--r--tools/testing/selftests/pidfd/pidfd_exec_helper.c12
-rw-r--r--tools/testing/selftests/pidfd/pidfd_fdinfo_test.c3
-rw-r--r--tools/testing/selftests/pidfd/pidfd_file_handle_test.c563
-rw-r--r--tools/testing/selftests/pidfd/pidfd_getfd_test.c2
-rw-r--r--tools/testing/selftests/pidfd/pidfd_info_test.c767
-rw-r--r--tools/testing/selftests/pidfd/pidfd_open_test.c32
-rw-r--r--tools/testing/selftests/pidfd/pidfd_poll_test.c2
-rw-r--r--tools/testing/selftests/pidfd/pidfd_setattr_test.c69
-rw-r--r--tools/testing/selftests/pidfd/pidfd_setns_test.c94
-rw-r--r--tools/testing/selftests/pidfd/pidfd_test.c80
-rw-r--r--tools/testing/selftests/pidfd/pidfd_wait.c49
-rw-r--r--tools/testing/selftests/pidfd/pidfd_xattr_test.c132
18 files changed, 2873 insertions, 174 deletions
diff --git a/tools/testing/selftests/pidfd/.gitignore b/tools/testing/selftests/pidfd/.gitignore
index 973198a3ec3d..4cd8ec7fd349 100644
--- a/tools/testing/selftests/pidfd/.gitignore
+++ b/tools/testing/selftests/pidfd/.gitignore
@@ -6,3 +6,10 @@ pidfd_wait
pidfd_fdinfo_test
pidfd_getfd_test
pidfd_setns_test
+pidfd_file_handle_test
+pidfd_bind_mount
+pidfd_info_test
+pidfd_exec_helper
+pidfd_xattr_test
+pidfd_setattr_test
+pidfd_autoreap_test
diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile
index d731e3e76d5b..4211f91e9af8 100644
--- a/tools/testing/selftests/pidfd/Makefile
+++ b/tools/testing/selftests/pidfd/Makefile
@@ -1,8 +1,12 @@
# SPDX-License-Identifier: GPL-2.0-only
-CFLAGS += -g $(KHDR_INCLUDES) -pthread -Wall
+CFLAGS += -g $(KHDR_INCLUDES) $(TOOLS_INCLUDES) -pthread -Wall
TEST_GEN_PROGS := pidfd_test pidfd_fdinfo_test pidfd_open_test \
- pidfd_poll_test pidfd_wait pidfd_getfd_test pidfd_setns_test
+ pidfd_poll_test pidfd_wait pidfd_getfd_test pidfd_setns_test \
+ pidfd_file_handle_test pidfd_bind_mount pidfd_info_test \
+ pidfd_xattr_test pidfd_setattr_test pidfd_autoreap_test
+
+TEST_GEN_PROGS_EXTENDED := pidfd_exec_helper
include ../lib.mk
diff --git a/tools/testing/selftests/pidfd/config b/tools/testing/selftests/pidfd/config
index 6133524710f7..cf7cc0ce0248 100644
--- a/tools/testing/selftests/pidfd/config
+++ b/tools/testing/selftests/pidfd/config
@@ -4,6 +4,5 @@ CONFIG_USER_NS=y
CONFIG_PID_NS=y
CONFIG_NET_NS=y
CONFIG_TIME_NS=y
-CONFIG_GENERIC_VDSO_TIME_NS=y
CONFIG_CGROUPS=y
CONFIG_CHECKPOINT_RESTORE=y
diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h
index 88d6830ee004..5a4e78c10f43 100644
--- a/tools/testing/selftests/pidfd/pidfd.h
+++ b/tools/testing/selftests/pidfd/pidfd.h
@@ -12,11 +12,25 @@
#include <stdlib.h>
#include <string.h>
#include <syscall.h>
-#include <sys/mount.h>
+#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/wait.h>
-#include "../kselftest.h"
+/*
+ * Remove the userspace definitions of the following preprocessor symbols
+ * to avoid duplicate-definition warnings from the subsequent in-kernel
+ * definitions.
+ */
+#undef SCHED_NORMAL
+#undef SCHED_FLAG_KEEP_ALL
+#undef SCHED_FLAG_UTIL_CLAMP
+
+#include "kselftest.h"
+#include "../clone3/clone3_selftests.h"
+
+#ifndef FD_PIDFS_ROOT
+#define FD_PIDFS_ROOT -10002
+#endif
#ifndef P_PIDFD
#define P_PIDFD 3
@@ -31,25 +45,164 @@
#endif
#ifndef __NR_pidfd_open
-#define __NR_pidfd_open -1
+#define __NR_pidfd_open 434
#endif
#ifndef __NR_pidfd_send_signal
-#define __NR_pidfd_send_signal -1
+#define __NR_pidfd_send_signal 424
#endif
#ifndef __NR_clone3
-#define __NR_clone3 -1
+#define __NR_clone3 435
#endif
#ifndef __NR_pidfd_getfd
-#define __NR_pidfd_getfd -1
+#define __NR_pidfd_getfd 438
#endif
#ifndef PIDFD_NONBLOCK
#define PIDFD_NONBLOCK O_NONBLOCK
#endif
+#ifndef PIDFD_SELF_THREAD
+#define PIDFD_SELF_THREAD -10000 /* Current thread. */
+#endif
+
+#ifndef PIDFD_SELF_THREAD_GROUP
+#define PIDFD_SELF_THREAD_GROUP -10001 /* Current thread group leader. */
+#endif
+
+#ifndef PIDFD_SELF
+#define PIDFD_SELF PIDFD_SELF_THREAD
+#endif
+
+#ifndef PIDFD_SELF_PROCESS
+#define PIDFD_SELF_PROCESS PIDFD_SELF_THREAD_GROUP
+#endif
+
+#ifndef PIDFS_IOCTL_MAGIC
+#define PIDFS_IOCTL_MAGIC 0xFF
+#endif
+
+#ifndef PIDFD_GET_CGROUP_NAMESPACE
+#define PIDFD_GET_CGROUP_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 1)
+#endif
+
+#ifndef PIDFD_GET_IPC_NAMESPACE
+#define PIDFD_GET_IPC_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 2)
+#endif
+
+#ifndef PIDFD_GET_MNT_NAMESPACE
+#define PIDFD_GET_MNT_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 3)
+#endif
+
+#ifndef PIDFD_GET_NET_NAMESPACE
+#define PIDFD_GET_NET_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 4)
+#endif
+
+#ifndef PIDFD_GET_PID_NAMESPACE
+#define PIDFD_GET_PID_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 5)
+#endif
+
+#ifndef PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE
+#define PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 6)
+#endif
+
+#ifndef PIDFD_GET_TIME_NAMESPACE
+#define PIDFD_GET_TIME_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 7)
+#endif
+
+#ifndef PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE
+#define PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 8)
+#endif
+
+#ifndef PIDFD_GET_USER_NAMESPACE
+#define PIDFD_GET_USER_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 9)
+#endif
+
+#ifndef PIDFD_GET_UTS_NAMESPACE
+#define PIDFD_GET_UTS_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 10)
+#endif
+
+#ifndef PIDFD_GET_INFO
+#define PIDFD_GET_INFO _IOWR(PIDFS_IOCTL_MAGIC, 11, struct pidfd_info)
+#endif
+
+#ifndef PIDFD_INFO_PID
+#define PIDFD_INFO_PID (1UL << 0) /* Always returned, even if not requested */
+#endif
+
+#ifndef PIDFD_INFO_CREDS
+#define PIDFD_INFO_CREDS (1UL << 1) /* Always returned, even if not requested */
+#endif
+
+#ifndef PIDFD_INFO_CGROUPID
+#define PIDFD_INFO_CGROUPID (1UL << 2) /* Always returned if available, even if not requested */
+#endif
+
+#ifndef PIDFD_INFO_EXIT
+#define PIDFD_INFO_EXIT (1UL << 3) /* Always returned if available, even if not requested */
+#endif
+
+#ifndef PIDFD_INFO_COREDUMP
+#define PIDFD_INFO_COREDUMP (1UL << 4)
+#endif
+
+#ifndef PIDFD_INFO_SUPPORTED_MASK
+#define PIDFD_INFO_SUPPORTED_MASK (1UL << 5)
+#endif
+
+#ifndef PIDFD_INFO_COREDUMP_SIGNAL
+#define PIDFD_INFO_COREDUMP_SIGNAL (1UL << 6)
+#endif
+
+#ifndef PIDFD_INFO_COREDUMP_CODE
+#define PIDFD_INFO_COREDUMP_CODE (1UL << 7)
+#endif
+
+#ifndef PIDFD_COREDUMPED
+#define PIDFD_COREDUMPED (1U << 0) /* Did crash and... */
+#endif
+
+#ifndef PIDFD_COREDUMP_SKIP
+#define PIDFD_COREDUMP_SKIP (1U << 1) /* coredumping generation was skipped. */
+#endif
+
+#ifndef PIDFD_COREDUMP_USER
+#define PIDFD_COREDUMP_USER (1U << 2) /* coredump was done as the user. */
+#endif
+
+#ifndef PIDFD_COREDUMP_ROOT
+#define PIDFD_COREDUMP_ROOT (1U << 3) /* coredump was done as root. */
+#endif
+
+#ifndef PIDFD_THREAD
+#define PIDFD_THREAD O_EXCL
+#endif
+
+struct pidfd_info {
+ __u64 mask;
+ __u64 cgroupid;
+ __u32 pid;
+ __u32 tgid;
+ __u32 ppid;
+ __u32 ruid;
+ __u32 rgid;
+ __u32 euid;
+ __u32 egid;
+ __u32 suid;
+ __u32 sgid;
+ __u32 fsuid;
+ __u32 fsgid;
+ __s32 exit_code;
+ struct {
+ __u32 coredump_mask;
+ __u32 coredump_signal;
+ __u32 coredump_code;
+ };
+ __u64 supported_mask;
+};
+
/*
* The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c
* That means, when it wraps around any pid < 300 will be skipped.
@@ -68,6 +221,11 @@
#define PIDFD_SKIP 3
#define PIDFD_XFAIL 4
+static inline int sys_waitid(int which, pid_t pid, siginfo_t *info, int options)
+{
+ return syscall(__NR_waitid, which, pid, info, options, NULL);
+}
+
static inline int wait_for_pid(pid_t pid)
{
int status, ret;
@@ -114,4 +272,44 @@ static inline int sys_memfd_create(const char *name, unsigned int flags)
return syscall(__NR_memfd_create, name, flags);
}
+static inline pid_t create_child(int *pidfd, unsigned flags)
+{
+ struct __clone_args args = {
+ .flags = CLONE_PIDFD | flags,
+ .exit_signal = SIGCHLD,
+ .pidfd = ptr_to_u64(pidfd),
+ };
+
+ return sys_clone3(&args, sizeof(struct __clone_args));
+}
+
+static inline ssize_t read_nointr(int fd, void *buf, size_t count)
+{
+ ssize_t ret;
+
+ do {
+ ret = read(fd, buf, count);
+ } while (ret < 0 && errno == EINTR);
+
+ return ret;
+}
+
+static inline ssize_t write_nointr(int fd, const void *buf, size_t count)
+{
+ ssize_t ret;
+
+ do {
+ ret = write(fd, buf, count);
+ } while (ret < 0 && errno == EINTR);
+
+ return ret;
+}
+
+static inline int sys_execveat(int dirfd, const char *pathname,
+ char *const argv[], char *const envp[],
+ int flags)
+{
+ return syscall(__NR_execveat, dirfd, pathname, argv, envp, flags);
+}
+
#endif /* __PIDFD_H */
diff --git a/tools/testing/selftests/pidfd/pidfd_autoreap_test.c b/tools/testing/selftests/pidfd/pidfd_autoreap_test.c
new file mode 100644
index 000000000000..1c586482f25b
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd_autoreap_test.c
@@ -0,0 +1,900 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2026 Christian Brauner <brauner@kernel.org>
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <linux/types.h>
+#include <poll.h>
+#include <pthread.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syscall.h>
+#include <sys/ioctl.h>
+#include <sys/prctl.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "pidfd.h"
+#include "kselftest_harness.h"
+
+#ifndef CLONE_AUTOREAP
+#define CLONE_AUTOREAP (1ULL << 34)
+#endif
+
+#ifndef CLONE_NNP
+#define CLONE_NNP (1ULL << 35)
+#endif
+
+#ifndef CLONE_PIDFD_AUTOKILL
+#define CLONE_PIDFD_AUTOKILL (1ULL << 36)
+#endif
+
+#ifndef _LINUX_CAPABILITY_VERSION_3
+#define _LINUX_CAPABILITY_VERSION_3 0x20080522
+#endif
+
+struct cap_header {
+ __u32 version;
+ int pid;
+};
+
+struct cap_data {
+ __u32 effective;
+ __u32 permitted;
+ __u32 inheritable;
+};
+
+static int drop_all_caps(void)
+{
+ struct cap_header hdr = { .version = _LINUX_CAPABILITY_VERSION_3 };
+ struct cap_data data[2] = {};
+
+ return syscall(__NR_capset, &hdr, data);
+}
+
+static pid_t create_autoreap_child(int *pidfd)
+{
+ struct __clone_args args = {
+ .flags = CLONE_PIDFD | CLONE_AUTOREAP,
+ .exit_signal = 0,
+ .pidfd = ptr_to_u64(pidfd),
+ };
+
+ return sys_clone3(&args, sizeof(args));
+}
+
+/*
+ * Test that CLONE_AUTOREAP works without CLONE_PIDFD (fire-and-forget).
+ */
+TEST(autoreap_without_pidfd)
+{
+ struct __clone_args args = {
+ .flags = CLONE_AUTOREAP,
+ .exit_signal = 0,
+ };
+ pid_t pid;
+ int ret;
+
+ pid = sys_clone3(&args, sizeof(args));
+ if (pid < 0 && errno == EINVAL)
+ SKIP(return, "CLONE_AUTOREAP not supported");
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0)
+ _exit(0);
+
+ /*
+ * Give the child a moment to exit and be autoreaped.
+ * Then verify no zombie remains.
+ */
+ usleep(200000);
+ ret = waitpid(pid, NULL, WNOHANG);
+ ASSERT_EQ(ret, -1);
+ ASSERT_EQ(errno, ECHILD);
+}
+
+/*
+ * Test that CLONE_AUTOREAP with a non-zero exit_signal fails.
+ */
+TEST(autoreap_rejects_exit_signal)
+{
+ struct __clone_args args = {
+ .flags = CLONE_AUTOREAP,
+ .exit_signal = SIGCHLD,
+ };
+ pid_t pid;
+
+ pid = sys_clone3(&args, sizeof(args));
+ ASSERT_EQ(pid, -1);
+ ASSERT_EQ(errno, EINVAL);
+}
+
+/*
+ * Test that CLONE_AUTOREAP with CLONE_PARENT fails.
+ */
+TEST(autoreap_rejects_parent)
+{
+ struct __clone_args args = {
+ .flags = CLONE_AUTOREAP | CLONE_PARENT,
+ .exit_signal = 0,
+ };
+ pid_t pid;
+
+ pid = sys_clone3(&args, sizeof(args));
+ ASSERT_EQ(pid, -1);
+ ASSERT_EQ(errno, EINVAL);
+}
+
+/*
+ * Test that CLONE_AUTOREAP with CLONE_THREAD fails.
+ */
+TEST(autoreap_rejects_thread)
+{
+ struct __clone_args args = {
+ .flags = CLONE_AUTOREAP | CLONE_THREAD |
+ CLONE_SIGHAND | CLONE_VM,
+ .exit_signal = 0,
+ };
+ pid_t pid;
+
+ pid = sys_clone3(&args, sizeof(args));
+ ASSERT_EQ(pid, -1);
+ ASSERT_EQ(errno, EINVAL);
+}
+
+/*
+ * Basic test: create an autoreap child, let it exit, verify:
+ * - pidfd becomes readable (poll returns POLLIN)
+ * - PIDFD_GET_INFO returns the correct exit code
+ * - waitpid() returns -1/ECHILD (no zombie)
+ */
+TEST(autoreap_basic)
+{
+ struct pidfd_info info = { .mask = PIDFD_INFO_EXIT };
+ int pidfd = -1, ret;
+ struct pollfd pfd;
+ pid_t pid;
+
+ pid = create_autoreap_child(&pidfd);
+ if (pid < 0 && errno == EINVAL)
+ SKIP(return, "CLONE_AUTOREAP not supported");
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0)
+ _exit(42);
+
+ ASSERT_GE(pidfd, 0);
+
+ /* Wait for the child to exit via pidfd poll. */
+ pfd.fd = pidfd;
+ pfd.events = POLLIN;
+ ret = poll(&pfd, 1, 5000);
+ ASSERT_EQ(ret, 1);
+ ASSERT_TRUE(pfd.revents & POLLIN);
+
+ /* Verify exit info via PIDFD_GET_INFO. */
+ ret = ioctl(pidfd, PIDFD_GET_INFO, &info);
+ ASSERT_EQ(ret, 0);
+ ASSERT_TRUE(info.mask & PIDFD_INFO_EXIT);
+ /*
+ * exit_code is in waitpid format: for _exit(42),
+ * WIFEXITED is true and WEXITSTATUS is 42.
+ */
+ ASSERT_TRUE(WIFEXITED(info.exit_code));
+ ASSERT_EQ(WEXITSTATUS(info.exit_code), 42);
+
+ /* Verify no zombie: waitpid should fail with ECHILD. */
+ ret = waitpid(pid, NULL, WNOHANG);
+ ASSERT_EQ(ret, -1);
+ ASSERT_EQ(errno, ECHILD);
+
+ close(pidfd);
+}
+
+/*
+ * Test that an autoreap child killed by a signal reports
+ * the correct exit info.
+ */
+TEST(autoreap_signaled)
+{
+ struct pidfd_info info = { .mask = PIDFD_INFO_EXIT };
+ int pidfd = -1, ret;
+ struct pollfd pfd;
+ pid_t pid;
+
+ pid = create_autoreap_child(&pidfd);
+ if (pid < 0 && errno == EINVAL)
+ SKIP(return, "CLONE_AUTOREAP not supported");
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ pause();
+ _exit(1);
+ }
+
+ ASSERT_GE(pidfd, 0);
+
+ /* Kill the child. */
+ ret = sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0);
+ ASSERT_EQ(ret, 0);
+
+ /* Wait for exit via pidfd. */
+ pfd.fd = pidfd;
+ pfd.events = POLLIN;
+ ret = poll(&pfd, 1, 5000);
+ ASSERT_EQ(ret, 1);
+ ASSERT_TRUE(pfd.revents & POLLIN);
+
+ /* Verify signal info. */
+ ret = ioctl(pidfd, PIDFD_GET_INFO, &info);
+ ASSERT_EQ(ret, 0);
+ ASSERT_TRUE(info.mask & PIDFD_INFO_EXIT);
+ ASSERT_TRUE(WIFSIGNALED(info.exit_code));
+ ASSERT_EQ(WTERMSIG(info.exit_code), SIGKILL);
+
+ /* No zombie. */
+ ret = waitpid(pid, NULL, WNOHANG);
+ ASSERT_EQ(ret, -1);
+ ASSERT_EQ(errno, ECHILD);
+
+ close(pidfd);
+}
+
+/*
+ * Test autoreap survives reparenting: middle process creates an
+ * autoreap grandchild, then exits. The grandchild gets reparented
+ * to us (the grandparent, which is a subreaper). When the grandchild
+ * exits, it should still be autoreaped - no zombie under us.
+ */
+TEST(autoreap_reparent)
+{
+ int ipc_sockets[2], ret;
+ int pidfd = -1;
+ struct pollfd pfd;
+ pid_t mid_pid, grandchild_pid;
+ char buf[32] = {};
+
+ /* Make ourselves a subreaper so reparented children come to us. */
+ ret = prctl(PR_SET_CHILD_SUBREAPER, 1);
+ ASSERT_EQ(ret, 0);
+
+ ret = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
+ ASSERT_EQ(ret, 0);
+
+ mid_pid = fork();
+ ASSERT_GE(mid_pid, 0);
+
+ if (mid_pid == 0) {
+ /* Middle child: create an autoreap grandchild. */
+ int gc_pidfd = -1;
+
+ close(ipc_sockets[0]);
+
+ grandchild_pid = create_autoreap_child(&gc_pidfd);
+ if (grandchild_pid < 0) {
+ write_nointr(ipc_sockets[1], "E", 1);
+ close(ipc_sockets[1]);
+ _exit(1);
+ }
+
+ if (grandchild_pid == 0) {
+ /* Grandchild: wait for signal to exit. */
+ close(ipc_sockets[1]);
+ if (gc_pidfd >= 0)
+ close(gc_pidfd);
+ pause();
+ _exit(0);
+ }
+
+ /* Send grandchild PID to grandparent. */
+ snprintf(buf, sizeof(buf), "%d", grandchild_pid);
+ write_nointr(ipc_sockets[1], buf, strlen(buf));
+ close(ipc_sockets[1]);
+ if (gc_pidfd >= 0)
+ close(gc_pidfd);
+
+ /* Middle child exits, grandchild gets reparented. */
+ _exit(0);
+ }
+
+ close(ipc_sockets[1]);
+
+ /* Read grandchild's PID. */
+ ret = read_nointr(ipc_sockets[0], buf, sizeof(buf) - 1);
+ close(ipc_sockets[0]);
+ ASSERT_GT(ret, 0);
+
+ if (buf[0] == 'E') {
+ waitpid(mid_pid, NULL, 0);
+ prctl(PR_SET_CHILD_SUBREAPER, 0);
+ SKIP(return, "CLONE_AUTOREAP not supported");
+ }
+
+ grandchild_pid = atoi(buf);
+ ASSERT_GT(grandchild_pid, 0);
+
+ /* Wait for the middle child to exit. */
+ ret = waitpid(mid_pid, NULL, 0);
+ ASSERT_EQ(ret, mid_pid);
+
+ /*
+ * Now the grandchild is reparented to us (subreaper).
+ * Open a pidfd for the grandchild and kill it.
+ */
+ pidfd = sys_pidfd_open(grandchild_pid, 0);
+ ASSERT_GE(pidfd, 0);
+
+ ret = sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0);
+ ASSERT_EQ(ret, 0);
+
+ /* Wait for it to exit via pidfd poll. */
+ pfd.fd = pidfd;
+ pfd.events = POLLIN;
+ ret = poll(&pfd, 1, 5000);
+ ASSERT_EQ(ret, 1);
+ ASSERT_TRUE(pfd.revents & POLLIN);
+
+ /*
+ * The grandchild should have been autoreaped even though
+ * we (the new parent) haven't set SA_NOCLDWAIT.
+ * waitpid should return -1/ECHILD.
+ */
+ ret = waitpid(grandchild_pid, NULL, WNOHANG);
+ EXPECT_EQ(ret, -1);
+ EXPECT_EQ(errno, ECHILD);
+
+ close(pidfd);
+
+ /* Clean up subreaper status. */
+ prctl(PR_SET_CHILD_SUBREAPER, 0);
+}
+
+static int thread_sock_fd;
+
+static void *thread_func(void *arg)
+{
+ /* Signal parent we're running. */
+ write_nointr(thread_sock_fd, "1", 1);
+
+ /* Give main thread time to call _exit() first. */
+ usleep(200000);
+
+ return NULL;
+}
+
+/*
+ * Test that an autoreap child with multiple threads is properly
+ * autoreaped only after all threads have exited.
+ */
+TEST(autoreap_multithreaded)
+{
+ struct pidfd_info info = { .mask = PIDFD_INFO_EXIT };
+ int ipc_sockets[2], ret;
+ int pidfd = -1;
+ struct pollfd pfd;
+ pid_t pid;
+ char c;
+
+ ret = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
+ ASSERT_EQ(ret, 0);
+
+ pid = create_autoreap_child(&pidfd);
+ if (pid < 0 && errno == EINVAL) {
+ close(ipc_sockets[0]);
+ close(ipc_sockets[1]);
+ SKIP(return, "CLONE_AUTOREAP not supported");
+ }
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ pthread_t thread;
+
+ close(ipc_sockets[0]);
+
+ /*
+ * Create a sub-thread that outlives the main thread.
+ * The thread signals readiness, then sleeps.
+ * The main thread waits briefly, then calls _exit().
+ */
+ thread_sock_fd = ipc_sockets[1];
+ pthread_create(&thread, NULL, thread_func, NULL);
+ pthread_detach(thread);
+
+ /* Wait for thread to be running. */
+ usleep(100000);
+
+ /* Main thread exits; sub-thread is still alive. */
+ _exit(99);
+ }
+
+ close(ipc_sockets[1]);
+
+ /* Wait for the sub-thread to signal readiness. */
+ ret = read_nointr(ipc_sockets[0], &c, 1);
+ close(ipc_sockets[0]);
+ ASSERT_EQ(ret, 1);
+
+ /* Wait for the process to fully exit via pidfd poll. */
+ pfd.fd = pidfd;
+ pfd.events = POLLIN;
+ ret = poll(&pfd, 1, 5000);
+ ASSERT_EQ(ret, 1);
+ ASSERT_TRUE(pfd.revents & POLLIN);
+
+ /* Verify exit info. */
+ ret = ioctl(pidfd, PIDFD_GET_INFO, &info);
+ ASSERT_EQ(ret, 0);
+ ASSERT_TRUE(info.mask & PIDFD_INFO_EXIT);
+ ASSERT_TRUE(WIFEXITED(info.exit_code));
+ ASSERT_EQ(WEXITSTATUS(info.exit_code), 99);
+
+ /* No zombie. */
+ ret = waitpid(pid, NULL, WNOHANG);
+ ASSERT_EQ(ret, -1);
+ ASSERT_EQ(errno, ECHILD);
+
+ close(pidfd);
+}
+
+/*
+ * Test that autoreap is NOT inherited by grandchildren.
+ */
+TEST(autoreap_no_inherit)
+{
+ int ipc_sockets[2], ret;
+ int pidfd = -1;
+ pid_t pid;
+ char buf[2] = {};
+ struct pollfd pfd;
+
+ ret = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
+ ASSERT_EQ(ret, 0);
+
+ pid = create_autoreap_child(&pidfd);
+ if (pid < 0 && errno == EINVAL) {
+ close(ipc_sockets[0]);
+ close(ipc_sockets[1]);
+ SKIP(return, "CLONE_AUTOREAP not supported");
+ }
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ pid_t gc;
+ int status;
+
+ close(ipc_sockets[0]);
+
+ /* Autoreap child forks a grandchild (without autoreap). */
+ gc = fork();
+ if (gc < 0) {
+ write_nointr(ipc_sockets[1], "E", 1);
+ _exit(1);
+ }
+ if (gc == 0) {
+ /* Grandchild: exit immediately. */
+ close(ipc_sockets[1]);
+ _exit(77);
+ }
+
+ /*
+ * The grandchild should become a regular zombie
+ * since it was NOT created with CLONE_AUTOREAP.
+ * Wait for it to verify.
+ */
+ ret = waitpid(gc, &status, 0);
+ if (ret == gc && WIFEXITED(status) &&
+ WEXITSTATUS(status) == 77) {
+ write_nointr(ipc_sockets[1], "P", 1);
+ } else {
+ write_nointr(ipc_sockets[1], "F", 1);
+ }
+ close(ipc_sockets[1]);
+ _exit(0);
+ }
+
+ close(ipc_sockets[1]);
+
+ ret = read_nointr(ipc_sockets[0], buf, 1);
+ close(ipc_sockets[0]);
+ ASSERT_EQ(ret, 1);
+
+ /*
+ * 'P' means the autoreap child was able to waitpid() its
+ * grandchild (correct - grandchild should be a normal zombie,
+ * not autoreaped).
+ */
+ ASSERT_EQ(buf[0], 'P');
+
+ /* Wait for the autoreap child to exit. */
+ pfd.fd = pidfd;
+ pfd.events = POLLIN;
+ ret = poll(&pfd, 1, 5000);
+ ASSERT_EQ(ret, 1);
+
+ /* Autoreap child itself should be autoreaped. */
+ ret = waitpid(pid, NULL, WNOHANG);
+ ASSERT_EQ(ret, -1);
+ ASSERT_EQ(errno, ECHILD);
+
+ close(pidfd);
+}
+
+/*
+ * Test that CLONE_NNP sets no_new_privs on the child.
+ * The child checks via prctl(PR_GET_NO_NEW_PRIVS) and reports back.
+ * The parent must NOT have no_new_privs set afterwards.
+ */
+TEST(nnp_sets_no_new_privs)
+{
+ struct __clone_args args = {
+ .flags = CLONE_PIDFD | CLONE_AUTOREAP | CLONE_NNP,
+ .exit_signal = 0,
+ };
+ struct pidfd_info info = { .mask = PIDFD_INFO_EXIT };
+ int pidfd = -1, ret;
+ struct pollfd pfd;
+ pid_t pid;
+
+ /* Ensure parent does not already have no_new_privs. */
+ ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
+ ASSERT_EQ(ret, 0) {
+ TH_LOG("Parent already has no_new_privs set, cannot run test");
+ }
+
+ args.pidfd = ptr_to_u64(&pidfd);
+
+ pid = sys_clone3(&args, sizeof(args));
+ if (pid < 0 && errno == EINVAL)
+ SKIP(return, "CLONE_NNP not supported");
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ /*
+ * Child: check no_new_privs. Exit 0 if set, 1 if not.
+ */
+ ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
+ _exit(ret == 1 ? 0 : 1);
+ }
+
+ ASSERT_GE(pidfd, 0);
+
+ /* Parent must still NOT have no_new_privs. */
+ ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
+ ASSERT_EQ(ret, 0) {
+ TH_LOG("Parent got no_new_privs after creating CLONE_NNP child");
+ }
+
+ /* Wait for child to exit. */
+ pfd.fd = pidfd;
+ pfd.events = POLLIN;
+ ret = poll(&pfd, 1, 5000);
+ ASSERT_EQ(ret, 1);
+
+ /* Verify child exited with 0 (no_new_privs was set). */
+ ret = ioctl(pidfd, PIDFD_GET_INFO, &info);
+ ASSERT_EQ(ret, 0);
+ ASSERT_TRUE(info.mask & PIDFD_INFO_EXIT);
+ ASSERT_TRUE(WIFEXITED(info.exit_code));
+ ASSERT_EQ(WEXITSTATUS(info.exit_code), 0) {
+ TH_LOG("Child did not have no_new_privs set");
+ }
+
+ close(pidfd);
+}
+
+/*
+ * Test that CLONE_NNP with CLONE_THREAD fails with EINVAL.
+ */
+TEST(nnp_rejects_thread)
+{
+ struct __clone_args args = {
+ .flags = CLONE_NNP | CLONE_THREAD |
+ CLONE_SIGHAND | CLONE_VM,
+ .exit_signal = 0,
+ };
+ pid_t pid;
+
+ pid = sys_clone3(&args, sizeof(args));
+ ASSERT_EQ(pid, -1);
+ ASSERT_EQ(errno, EINVAL);
+}
+
+/*
+ * Test that a plain CLONE_AUTOREAP child does NOT get no_new_privs.
+ * Only CLONE_NNP should set it.
+ */
+TEST(autoreap_no_new_privs_unset)
+{
+ struct pidfd_info info = { .mask = PIDFD_INFO_EXIT };
+ int pidfd = -1, ret;
+ struct pollfd pfd;
+ pid_t pid;
+
+ pid = create_autoreap_child(&pidfd);
+ if (pid < 0 && errno == EINVAL)
+ SKIP(return, "CLONE_AUTOREAP not supported");
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ /*
+ * Child: check no_new_privs. Exit 0 if NOT set, 1 if set.
+ */
+ ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
+ _exit(ret == 0 ? 0 : 1);
+ }
+
+ ASSERT_GE(pidfd, 0);
+
+ pfd.fd = pidfd;
+ pfd.events = POLLIN;
+ ret = poll(&pfd, 1, 5000);
+ ASSERT_EQ(ret, 1);
+
+ ret = ioctl(pidfd, PIDFD_GET_INFO, &info);
+ ASSERT_EQ(ret, 0);
+ ASSERT_TRUE(info.mask & PIDFD_INFO_EXIT);
+ ASSERT_TRUE(WIFEXITED(info.exit_code));
+ ASSERT_EQ(WEXITSTATUS(info.exit_code), 0) {
+ TH_LOG("Plain autoreap child unexpectedly has no_new_privs");
+ }
+
+ close(pidfd);
+}
+
+/*
+ * Helper: create a child with CLONE_PIDFD | CLONE_PIDFD_AUTOKILL | CLONE_AUTOREAP | CLONE_NNP.
+ */
+static pid_t create_autokill_child(int *pidfd)
+{
+ struct __clone_args args = {
+ .flags = CLONE_PIDFD | CLONE_PIDFD_AUTOKILL |
+ CLONE_AUTOREAP | CLONE_NNP,
+ .exit_signal = 0,
+ .pidfd = ptr_to_u64(pidfd),
+ };
+
+ return sys_clone3(&args, sizeof(args));
+}
+
+/*
+ * Basic autokill test: child blocks in pause(), parent closes the
+ * clone3 pidfd, child should be killed and autoreaped.
+ */
+TEST(autokill_basic)
+{
+ int pidfd = -1, pollfd_fd = -1, ret;
+ struct pollfd pfd;
+ pid_t pid;
+
+ pid = create_autokill_child(&pidfd);
+ if (pid < 0 && errno == EINVAL)
+ SKIP(return, "CLONE_PIDFD_AUTOKILL not supported");
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ pause();
+ _exit(1);
+ }
+
+ ASSERT_GE(pidfd, 0);
+
+ /*
+ * Open a second pidfd via pidfd_open() so we can observe the
+ * child's death after closing the clone3 pidfd.
+ */
+ pollfd_fd = sys_pidfd_open(pid, 0);
+ ASSERT_GE(pollfd_fd, 0);
+
+ /* Close the clone3 pidfd — this should trigger autokill. */
+ close(pidfd);
+
+ /* Wait for the child to die via the pidfd_open'd fd. */
+ pfd.fd = pollfd_fd;
+ pfd.events = POLLIN;
+ ret = poll(&pfd, 1, 5000);
+ ASSERT_EQ(ret, 1);
+ ASSERT_TRUE(pfd.revents & POLLIN);
+
+ /* Child should be autoreaped — no zombie. */
+ usleep(100000);
+ ret = waitpid(pid, NULL, WNOHANG);
+ ASSERT_EQ(ret, -1);
+ ASSERT_EQ(errno, ECHILD);
+
+ close(pollfd_fd);
+}
+
+/*
+ * CLONE_PIDFD_AUTOKILL without CLONE_PIDFD must fail with EINVAL.
+ */
+TEST(autokill_requires_pidfd)
+{
+ struct __clone_args args = {
+ .flags = CLONE_PIDFD_AUTOKILL | CLONE_AUTOREAP,
+ .exit_signal = 0,
+ };
+ pid_t pid;
+
+ pid = sys_clone3(&args, sizeof(args));
+ ASSERT_EQ(pid, -1);
+ ASSERT_EQ(errno, EINVAL);
+}
+
+/*
+ * CLONE_PIDFD_AUTOKILL without CLONE_AUTOREAP must fail with EINVAL.
+ */
+TEST(autokill_requires_autoreap)
+{
+ int pidfd = -1;
+ struct __clone_args args = {
+ .flags = CLONE_PIDFD | CLONE_PIDFD_AUTOKILL,
+ .exit_signal = 0,
+ .pidfd = ptr_to_u64(&pidfd),
+ };
+ pid_t pid;
+
+ pid = sys_clone3(&args, sizeof(args));
+ ASSERT_EQ(pid, -1);
+ ASSERT_EQ(errno, EINVAL);
+}
+
+/*
+ * CLONE_PIDFD_AUTOKILL with CLONE_THREAD must fail with EINVAL.
+ */
+TEST(autokill_rejects_thread)
+{
+ int pidfd = -1;
+ struct __clone_args args = {
+ .flags = CLONE_PIDFD | CLONE_PIDFD_AUTOKILL |
+ CLONE_AUTOREAP | CLONE_THREAD |
+ CLONE_SIGHAND | CLONE_VM,
+ .exit_signal = 0,
+ .pidfd = ptr_to_u64(&pidfd),
+ };
+ pid_t pid;
+
+ pid = sys_clone3(&args, sizeof(args));
+ ASSERT_EQ(pid, -1);
+ ASSERT_EQ(errno, EINVAL);
+}
+
+/*
+ * Test that only the clone3 pidfd triggers autokill, not pidfd_open().
+ * Close the pidfd_open'd fd first — child should survive.
+ * Then close the clone3 pidfd — child should be killed and autoreaped.
+ */
+TEST(autokill_pidfd_open_no_effect)
+{
+ int pidfd = -1, open_fd = -1, ret;
+ struct pollfd pfd;
+ pid_t pid;
+
+ pid = create_autokill_child(&pidfd);
+ if (pid < 0 && errno == EINVAL)
+ SKIP(return, "CLONE_PIDFD_AUTOKILL not supported");
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ pause();
+ _exit(1);
+ }
+
+ ASSERT_GE(pidfd, 0);
+
+ /* Open a second pidfd via pidfd_open(). */
+ open_fd = sys_pidfd_open(pid, 0);
+ ASSERT_GE(open_fd, 0);
+
+ /*
+ * Close the pidfd_open'd fd — child should survive because
+ * only the clone3 pidfd has autokill.
+ */
+ close(open_fd);
+ usleep(200000);
+
+ /* Verify child is still alive by polling the clone3 pidfd. */
+ pfd.fd = pidfd;
+ pfd.events = POLLIN;
+ ret = poll(&pfd, 1, 0);
+ ASSERT_EQ(ret, 0) {
+ TH_LOG("Child died after closing pidfd_open fd — should still be alive");
+ }
+
+ /* Open another observation fd before triggering autokill. */
+ open_fd = sys_pidfd_open(pid, 0);
+ ASSERT_GE(open_fd, 0);
+
+ /* Now close the clone3 pidfd — this triggers autokill. */
+ close(pidfd);
+
+ pfd.fd = open_fd;
+ pfd.events = POLLIN;
+ ret = poll(&pfd, 1, 5000);
+ ASSERT_EQ(ret, 1);
+ ASSERT_TRUE(pfd.revents & POLLIN);
+
+ /* Child should be autoreaped — no zombie. */
+ usleep(100000);
+ ret = waitpid(pid, NULL, WNOHANG);
+ ASSERT_EQ(ret, -1);
+ ASSERT_EQ(errno, ECHILD);
+
+ close(open_fd);
+}
+
+/*
+ * Test that CLONE_PIDFD_AUTOKILL without CLONE_NNP fails with EPERM
+ * for an unprivileged caller.
+ */
+TEST(autokill_requires_cap_sys_admin)
+{
+ int pidfd = -1, ret;
+ struct __clone_args args = {
+ .flags = CLONE_PIDFD | CLONE_PIDFD_AUTOKILL |
+ CLONE_AUTOREAP,
+ .exit_signal = 0,
+ .pidfd = ptr_to_u64(&pidfd),
+ };
+ pid_t pid;
+
+ /* Drop all capabilities so we lack CAP_SYS_ADMIN. */
+ ret = drop_all_caps();
+ ASSERT_EQ(ret, 0);
+
+ pid = sys_clone3(&args, sizeof(args));
+ ASSERT_EQ(pid, -1);
+ ASSERT_EQ(errno, EPERM);
+}
+
+/*
+ * Test that CLONE_PIDFD_AUTOKILL without CLONE_NNP succeeds with
+ * CAP_SYS_ADMIN.
+ */
+TEST(autokill_without_nnp_with_cap)
+{
+ struct __clone_args args = {
+ .flags = CLONE_PIDFD | CLONE_PIDFD_AUTOKILL |
+ CLONE_AUTOREAP,
+ .exit_signal = 0,
+ };
+ struct pidfd_info info = { .mask = PIDFD_INFO_EXIT };
+ int pidfd = -1, ret;
+ struct pollfd pfd;
+ pid_t pid;
+
+ if (geteuid() != 0)
+ SKIP(return, "Need root/CAP_SYS_ADMIN");
+
+ args.pidfd = ptr_to_u64(&pidfd);
+
+ pid = sys_clone3(&args, sizeof(args));
+ if (pid < 0 && errno == EINVAL)
+ SKIP(return, "CLONE_PIDFD_AUTOKILL not supported");
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0)
+ _exit(0);
+
+ ASSERT_GE(pidfd, 0);
+
+ /* Wait for child to exit. */
+ pfd.fd = pidfd;
+ pfd.events = POLLIN;
+ ret = poll(&pfd, 1, 5000);
+ ASSERT_EQ(ret, 1);
+
+ ret = ioctl(pidfd, PIDFD_GET_INFO, &info);
+ ASSERT_EQ(ret, 0);
+ ASSERT_TRUE(info.mask & PIDFD_INFO_EXIT);
+ ASSERT_TRUE(WIFEXITED(info.exit_code));
+ ASSERT_EQ(WEXITSTATUS(info.exit_code), 0);
+
+ close(pidfd);
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/pidfd/pidfd_bind_mount.c b/tools/testing/selftests/pidfd/pidfd_bind_mount.c
new file mode 100644
index 000000000000..1fdf49939524
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd_bind_mount.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (c) 2024 Christian Brauner <brauner@kernel.org>
+
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <limits.h>
+#include <sched.h>
+#include <stdio.h>
+#include <string.h>
+#include <linux/fs.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/mount.h>
+#include <unistd.h>
+
+#include "pidfd.h"
+#include "kselftest_harness.h"
+#include "../filesystems/wrappers.h"
+
+FIXTURE(pidfd_bind_mount) {
+ char template[PATH_MAX];
+ int fd_tmp;
+ int pidfd;
+ struct stat st1;
+ struct stat st2;
+ __u32 gen1;
+ __u32 gen2;
+ bool must_unmount;
+};
+
+FIXTURE_SETUP(pidfd_bind_mount)
+{
+ self->fd_tmp = -EBADF;
+ self->must_unmount = false;
+ ASSERT_EQ(unshare(CLONE_NEWNS), 0);
+ ASSERT_LE(snprintf(self->template, PATH_MAX, "%s", P_tmpdir "/pidfd_bind_mount_XXXXXX"), PATH_MAX);
+ self->fd_tmp = mkstemp(self->template);
+ ASSERT_GE(self->fd_tmp, 0);
+ self->pidfd = sys_pidfd_open(getpid(), 0);
+ ASSERT_GE(self->pidfd, 0);
+ ASSERT_GE(fstat(self->pidfd, &self->st1), 0);
+ ASSERT_EQ(ioctl(self->pidfd, FS_IOC_GETVERSION, &self->gen1), 0);
+}
+
+FIXTURE_TEARDOWN(pidfd_bind_mount)
+{
+ ASSERT_EQ(close(self->fd_tmp), 0);
+ if (self->must_unmount)
+ ASSERT_EQ(umount2(self->template, 0), 0);
+ ASSERT_EQ(unlink(self->template), 0);
+}
+
+/*
+ * Test that a detached mount can be created for a pidfd and then
+ * attached to the filesystem hierarchy.
+ */
+TEST_F(pidfd_bind_mount, bind_mount)
+{
+ int fd_tree;
+
+ fd_tree = sys_open_tree(self->pidfd, "", OPEN_TREE_CLONE | OPEN_TREE_CLOEXEC | AT_EMPTY_PATH);
+ ASSERT_GE(fd_tree, 0);
+
+ ASSERT_EQ(move_mount(fd_tree, "", self->fd_tmp, "", MOVE_MOUNT_F_EMPTY_PATH | MOVE_MOUNT_T_EMPTY_PATH), 0);
+ self->must_unmount = true;
+
+ ASSERT_EQ(close(fd_tree), 0);
+}
+
+/* Test that a pidfd can be reopened through procfs. */
+TEST_F(pidfd_bind_mount, reopen)
+{
+ int pidfd;
+ char proc_path[PATH_MAX];
+
+ sprintf(proc_path, "/proc/self/fd/%d", self->pidfd);
+ pidfd = open(proc_path, O_RDONLY | O_NOCTTY | O_CLOEXEC);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_GE(fstat(self->pidfd, &self->st2), 0);
+ ASSERT_EQ(ioctl(self->pidfd, FS_IOC_GETVERSION, &self->gen2), 0);
+
+ ASSERT_TRUE(self->st1.st_dev == self->st2.st_dev && self->st1.st_ino == self->st2.st_ino);
+ ASSERT_TRUE(self->gen1 == self->gen2);
+
+ ASSERT_EQ(close(pidfd), 0);
+}
+
+/*
+ * Test that a detached mount can be created for a pidfd and then
+ * attached to the filesystem hierarchy and reopened.
+ */
+TEST_F(pidfd_bind_mount, bind_mount_reopen)
+{
+ int fd_tree, fd_pidfd_mnt;
+
+ fd_tree = sys_open_tree(self->pidfd, "", OPEN_TREE_CLONE | OPEN_TREE_CLOEXEC | AT_EMPTY_PATH);
+ ASSERT_GE(fd_tree, 0);
+
+ ASSERT_EQ(move_mount(fd_tree, "", self->fd_tmp, "", MOVE_MOUNT_F_EMPTY_PATH | MOVE_MOUNT_T_EMPTY_PATH), 0);
+ self->must_unmount = true;
+
+ fd_pidfd_mnt = openat(-EBADF, self->template, O_RDONLY | O_NOCTTY | O_CLOEXEC);
+ ASSERT_GE(fd_pidfd_mnt, 0);
+
+ ASSERT_GE(fstat(fd_tree, &self->st2), 0);
+ ASSERT_EQ(ioctl(fd_pidfd_mnt, FS_IOC_GETVERSION, &self->gen2), 0);
+
+ ASSERT_TRUE(self->st1.st_dev == self->st2.st_dev && self->st1.st_ino == self->st2.st_ino);
+ ASSERT_TRUE(self->gen1 == self->gen2);
+
+ ASSERT_EQ(close(fd_tree), 0);
+ ASSERT_EQ(close(fd_pidfd_mnt), 0);
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/pidfd/pidfd_exec_helper.c b/tools/testing/selftests/pidfd/pidfd_exec_helper.c
new file mode 100644
index 000000000000..5516808c95f2
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd_exec_helper.c
@@ -0,0 +1,12 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[])
+{
+ if (pause())
+ _exit(EXIT_FAILURE);
+
+ _exit(EXIT_SUCCESS);
+}
diff --git a/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c
index f062a986e382..9935e9471c77 100644
--- a/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c
@@ -13,9 +13,10 @@
#include <syscall.h>
#include <sys/wait.h>
#include <sys/mman.h>
+#include <sys/mount.h>
#include "pidfd.h"
-#include "../kselftest.h"
+#include "kselftest.h"
struct error {
int code;
diff --git a/tools/testing/selftests/pidfd/pidfd_file_handle_test.c b/tools/testing/selftests/pidfd/pidfd_file_handle_test.c
new file mode 100644
index 000000000000..68918734dcf3
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd_file_handle_test.c
@@ -0,0 +1,563 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <linux/types.h>
+#include <poll.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syscall.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <linux/kcmp.h>
+#include <sys/stat.h>
+
+#include "pidfd.h"
+#include "kselftest_harness.h"
+
+FIXTURE(file_handle)
+{
+ pid_t pid;
+ int pidfd;
+
+ pid_t child_pid1;
+ int child_pidfd1;
+
+ pid_t child_pid2;
+ int child_pidfd2;
+
+ pid_t child_pid3;
+ int child_pidfd3;
+};
+
+FIXTURE_SETUP(file_handle)
+{
+ int ret;
+ int ipc_sockets[2];
+ char c;
+
+ self->pid = getpid();
+ self->pidfd = sys_pidfd_open(self->pid, 0);
+ ASSERT_GE(self->pidfd, 0);
+
+ ret = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
+ EXPECT_EQ(ret, 0);
+
+ self->child_pid1 = create_child(&self->child_pidfd1, CLONE_NEWUSER);
+ EXPECT_GE(self->child_pid1, 0);
+
+ if (self->child_pid1 == 0) {
+ close(ipc_sockets[0]);
+
+ if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+ _exit(EXIT_FAILURE);
+
+ close(ipc_sockets[1]);
+
+ pause();
+ _exit(EXIT_SUCCESS);
+ }
+
+ close(ipc_sockets[1]);
+ ASSERT_EQ(read_nointr(ipc_sockets[0], &c, 1), 1);
+ close(ipc_sockets[0]);
+
+ ret = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
+ EXPECT_EQ(ret, 0);
+
+ self->child_pid2 = create_child(&self->child_pidfd2, CLONE_NEWUSER | CLONE_NEWPID);
+ EXPECT_GE(self->child_pid2, 0);
+
+ if (self->child_pid2 == 0) {
+ close(ipc_sockets[0]);
+
+ if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+ _exit(EXIT_FAILURE);
+
+ close(ipc_sockets[1]);
+
+ pause();
+ _exit(EXIT_SUCCESS);
+ }
+
+ close(ipc_sockets[1]);
+ ASSERT_EQ(read_nointr(ipc_sockets[0], &c, 1), 1);
+ close(ipc_sockets[0]);
+
+ ret = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
+ EXPECT_EQ(ret, 0);
+
+ self->child_pid3 = create_child(&self->child_pidfd3, CLONE_NEWUSER | CLONE_NEWPID);
+ EXPECT_GE(self->child_pid3, 0);
+
+ if (self->child_pid3 == 0) {
+ close(ipc_sockets[0]);
+
+ if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+ _exit(EXIT_FAILURE);
+
+ close(ipc_sockets[1]);
+
+ pause();
+ _exit(EXIT_SUCCESS);
+ }
+
+ close(ipc_sockets[1]);
+ ASSERT_EQ(read_nointr(ipc_sockets[0], &c, 1), 1);
+ close(ipc_sockets[0]);
+}
+
+FIXTURE_TEARDOWN(file_handle)
+{
+ EXPECT_EQ(close(self->pidfd), 0);
+
+ EXPECT_EQ(sys_pidfd_send_signal(self->child_pidfd1, SIGKILL, NULL, 0), 0);
+ if (self->child_pidfd1 >= 0)
+ EXPECT_EQ(0, close(self->child_pidfd1));
+
+ EXPECT_EQ(sys_waitid(P_PID, self->child_pid1, NULL, WEXITED), 0);
+
+ EXPECT_EQ(sys_pidfd_send_signal(self->child_pidfd2, SIGKILL, NULL, 0), 0);
+ if (self->child_pidfd2 >= 0)
+ EXPECT_EQ(0, close(self->child_pidfd2));
+
+ EXPECT_EQ(sys_waitid(P_PID, self->child_pid2, NULL, WEXITED), 0);
+
+ if (self->child_pidfd3 >= 0) {
+ EXPECT_EQ(sys_pidfd_send_signal(self->child_pidfd3, SIGKILL, NULL, 0), 0);
+ EXPECT_EQ(0, close(self->child_pidfd3));
+ EXPECT_EQ(sys_waitid(P_PID, self->child_pid3, NULL, WEXITED), 0);
+ }
+}
+
+/*
+ * Test that we can decode a pidfs file handle in the same pid
+ * namespace.
+ */
+TEST_F(file_handle, file_handle_same_pidns)
+{
+ int mnt_id;
+ struct file_handle *fh;
+ int pidfd = -EBADF;
+ struct stat st1, st2;
+
+ fh = malloc(sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ ASSERT_NE(fh, NULL);
+ memset(fh, 0, sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ fh->handle_bytes = MAX_HANDLE_SZ;
+
+ ASSERT_EQ(name_to_handle_at(self->child_pidfd1, "", fh, &mnt_id, AT_EMPTY_PATH), 0);
+
+ ASSERT_EQ(fstat(self->child_pidfd1, &st1), 0);
+
+ pidfd = open_by_handle_at(self->pidfd, fh, 0);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+
+ pidfd = open_by_handle_at(self->pidfd, fh, O_CLOEXEC);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+
+ pidfd = open_by_handle_at(self->pidfd, fh, O_NONBLOCK);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+
+ free(fh);
+}
+
+/*
+ * Test that we can decode a pidfs file handle from a child pid
+ * namespace.
+ */
+TEST_F(file_handle, file_handle_child_pidns)
+{
+ int mnt_id;
+ struct file_handle *fh;
+ int pidfd = -EBADF;
+ struct stat st1, st2;
+
+ fh = malloc(sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ ASSERT_NE(fh, NULL);
+ memset(fh, 0, sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ fh->handle_bytes = MAX_HANDLE_SZ;
+
+ ASSERT_EQ(name_to_handle_at(self->child_pidfd2, "", fh, &mnt_id, AT_EMPTY_PATH), 0);
+
+ ASSERT_EQ(fstat(self->child_pidfd2, &st1), 0);
+
+ pidfd = open_by_handle_at(self->pidfd, fh, 0);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+
+ pidfd = open_by_handle_at(self->pidfd, fh, O_CLOEXEC);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+
+ pidfd = open_by_handle_at(self->pidfd, fh, O_NONBLOCK);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+
+ free(fh);
+}
+
+/*
+ * Test that we fail to decode a pidfs file handle from an ancestor
+ * child pid namespace.
+ */
+TEST_F(file_handle, file_handle_foreign_pidns)
+{
+ int mnt_id;
+ struct file_handle *fh;
+ pid_t pid;
+
+ fh = malloc(sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ ASSERT_NE(fh, NULL);
+ memset(fh, 0, sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ fh->handle_bytes = MAX_HANDLE_SZ;
+
+ ASSERT_EQ(name_to_handle_at(self->pidfd, "", fh, &mnt_id, AT_EMPTY_PATH), 0);
+
+ ASSERT_EQ(setns(self->child_pidfd2, CLONE_NEWUSER | CLONE_NEWPID), 0);
+
+ pid = fork();
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ int pidfd = open_by_handle_at(self->pidfd, fh, 0);
+ if (pidfd >= 0) {
+ TH_LOG("Managed to open pidfd outside of the caller's pid namespace hierarchy");
+ _exit(1);
+ }
+ _exit(0);
+ }
+
+ ASSERT_EQ(wait_for_pid(pid), 0);
+
+ free(fh);
+}
+
+/*
+ * Test that we can decode a pidfs file handle of a process that has
+ * exited but not been reaped.
+ */
+TEST_F(file_handle, pid_has_exited)
+{
+ int mnt_id, pidfd, child_pidfd3;
+ struct file_handle *fh;
+ struct stat st1, st2;
+
+ fh = malloc(sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ ASSERT_NE(fh, NULL);
+ memset(fh, 0, sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ fh->handle_bytes = MAX_HANDLE_SZ;
+
+ ASSERT_EQ(name_to_handle_at(self->child_pidfd3, "", fh, &mnt_id, AT_EMPTY_PATH), 0);
+
+ ASSERT_EQ(fstat(self->child_pidfd3, &st1), 0);
+
+ pidfd = open_by_handle_at(self->pidfd, fh, 0);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+
+ child_pidfd3 = self->child_pidfd3;
+ self->child_pidfd3 = -EBADF;
+ EXPECT_EQ(sys_pidfd_send_signal(child_pidfd3, SIGKILL, NULL, 0), 0);
+ EXPECT_EQ(close(child_pidfd3), 0);
+ EXPECT_EQ(sys_waitid(P_PID, self->child_pid3, NULL, WEXITED | WNOWAIT), 0);
+
+ pidfd = open_by_handle_at(self->pidfd, fh, 0);
+ ASSERT_GE(pidfd, 0);
+
+ EXPECT_EQ(sys_waitid(P_PID, self->child_pid3, NULL, WEXITED), 0);
+}
+
+/*
+ * Test that we fail to decode a pidfs file handle of a process that has
+ * already been reaped.
+ */
+TEST_F(file_handle, pid_has_been_reaped)
+{
+ int mnt_id, pidfd, child_pidfd3;
+ struct file_handle *fh;
+ struct stat st1, st2;
+
+ fh = malloc(sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ ASSERT_NE(fh, NULL);
+ memset(fh, 0, sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ fh->handle_bytes = MAX_HANDLE_SZ;
+
+ ASSERT_EQ(name_to_handle_at(self->child_pidfd3, "", fh, &mnt_id, AT_EMPTY_PATH), 0);
+
+ ASSERT_EQ(fstat(self->child_pidfd3, &st1), 0);
+
+ pidfd = open_by_handle_at(self->pidfd, fh, 0);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+
+ child_pidfd3 = self->child_pidfd3;
+ self->child_pidfd3 = -EBADF;
+ EXPECT_EQ(sys_pidfd_send_signal(child_pidfd3, SIGKILL, NULL, 0), 0);
+ EXPECT_EQ(close(child_pidfd3), 0);
+ EXPECT_EQ(sys_waitid(P_PID, self->child_pid3, NULL, WEXITED), 0);
+
+ pidfd = open_by_handle_at(self->pidfd, fh, 0);
+ ASSERT_LT(pidfd, 0);
+}
+
+/*
+ * Test valid flags to open a pidfd file handle. Note, that
+ * PIDFD_NONBLOCK is defined as O_NONBLOCK and O_NONBLOCK is an alias to
+ * O_NDELAY. Also note that PIDFD_THREAD is an alias for O_EXCL.
+ */
+TEST_F(file_handle, open_by_handle_at_valid_flags)
+{
+ int mnt_id;
+ struct file_handle *fh;
+ int pidfd = -EBADF;
+ struct stat st1, st2;
+
+ fh = malloc(sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ ASSERT_NE(fh, NULL);
+ memset(fh, 0, sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ fh->handle_bytes = MAX_HANDLE_SZ;
+
+ ASSERT_EQ(name_to_handle_at(self->child_pidfd2, "", fh, &mnt_id, AT_EMPTY_PATH), 0);
+
+ ASSERT_EQ(fstat(self->child_pidfd2, &st1), 0);
+
+ pidfd = open_by_handle_at(self->pidfd, fh,
+ O_RDONLY |
+ O_WRONLY |
+ O_RDWR |
+ O_NONBLOCK |
+ O_NDELAY |
+ O_CLOEXEC |
+ O_EXCL);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+}
+
+/*
+ * Test that invalid flags passed to open a pidfd file handle are
+ * rejected.
+ */
+TEST_F(file_handle, open_by_handle_at_invalid_flags)
+{
+ int mnt_id;
+ struct file_handle *fh;
+ int pidfd = -EBADF;
+ static const struct invalid_pidfs_file_handle_flags {
+ int oflag;
+ const char *oflag_name;
+ } invalid_pidfs_file_handle_flags[] = {
+ { FASYNC, "FASYNC" },
+ { O_CREAT, "O_CREAT" },
+ { O_NOCTTY, "O_NOCTTY" },
+ { O_CREAT, "O_CREAT" },
+ { O_TRUNC, "O_TRUNC" },
+ { O_APPEND, "O_APPEND" },
+ { O_SYNC, "O_SYNC" },
+ { O_DSYNC, "O_DSYNC" },
+ { O_DIRECT, "O_DIRECT" },
+ { O_DIRECTORY, "O_DIRECTORY" },
+ { O_NOFOLLOW, "O_NOFOLLOW" },
+ { O_NOATIME, "O_NOATIME" },
+ { O_PATH, "O_PATH" },
+ { O_TMPFILE, "O_TMPFILE" },
+ /*
+ * O_LARGEFILE is added implicitly by
+ * open_by_handle_at() so pidfs simply masks it off.
+ */
+ };
+
+ fh = malloc(sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ ASSERT_NE(fh, NULL);
+ memset(fh, 0, sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ fh->handle_bytes = MAX_HANDLE_SZ;
+
+ ASSERT_EQ(name_to_handle_at(self->child_pidfd2, "", fh, &mnt_id, AT_EMPTY_PATH), 0);
+
+ for (int i = 0; i < ARRAY_SIZE(invalid_pidfs_file_handle_flags); i++) {
+ pidfd = open_by_handle_at(self->pidfd, fh, invalid_pidfs_file_handle_flags[i].oflag);
+ ASSERT_LT(pidfd, 0) {
+ TH_LOG("open_by_handle_at() succeeded with invalid flags: %s", invalid_pidfs_file_handle_flags[i].oflag_name);
+ }
+ }
+}
+
+/* Test that lookup fails. */
+TEST_F(file_handle, lookup_must_fail)
+{
+ int mnt_id;
+ struct file_handle *fh;
+
+ fh = malloc(sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ ASSERT_NE(fh, NULL);
+ memset(fh, 0, sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ fh->handle_bytes = MAX_HANDLE_SZ;
+
+ ASSERT_NE(name_to_handle_at(self->child_pidfd2, "lookup-is-not-possible-with-pidfs", fh, &mnt_id, AT_EMPTY_PATH), 0);
+ ASSERT_EQ(errno, ENOTDIR);
+ ASSERT_NE(name_to_handle_at(self->child_pidfd2, "lookup-is-not-possible-with-pidfs", fh, &mnt_id, 0), 0);
+ ASSERT_EQ(errno, ENOTDIR);
+}
+
+#ifndef AT_HANDLE_CONNECTABLE
+#define AT_HANDLE_CONNECTABLE 0x002
+#endif
+
+/*
+ * Test that AT_HANDLE_CONNECTABLE is rejected. Connectable file handles
+ * don't make sense for pidfs. Note that currently AT_HANDLE_CONNECTABLE
+ * is rejected because it is incompatible with AT_EMPTY_PATH which is
+ * required with pidfds as we don't support lookup.
+ */
+TEST_F(file_handle, invalid_name_to_handle_at_flags)
+{
+ int mnt_id;
+ struct file_handle *fh;
+
+ fh = malloc(sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ ASSERT_NE(fh, NULL);
+ memset(fh, 0, sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ fh->handle_bytes = MAX_HANDLE_SZ;
+
+ ASSERT_NE(name_to_handle_at(self->child_pidfd2, "", fh, &mnt_id, AT_EMPTY_PATH | AT_HANDLE_CONNECTABLE), 0);
+}
+
+#ifndef AT_HANDLE_FID
+#define AT_HANDLE_FID 0x200
+#endif
+
+/*
+ * Test that a request with AT_HANDLE_FID always leads to decodable file
+ * handle as pidfs always provides export operations.
+ */
+TEST_F(file_handle, valid_name_to_handle_at_flags)
+{
+ int mnt_id, pidfd;
+ struct file_handle *fh;
+ struct stat st1, st2;
+
+ fh = malloc(sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ ASSERT_NE(fh, NULL);
+ memset(fh, 0, sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ fh->handle_bytes = MAX_HANDLE_SZ;
+
+ ASSERT_EQ(name_to_handle_at(self->child_pidfd2, "", fh, &mnt_id, AT_EMPTY_PATH | AT_HANDLE_FID), 0);
+
+ ASSERT_EQ(fstat(self->child_pidfd2, &st1), 0);
+
+ pidfd = open_by_handle_at(self->pidfd, fh, 0);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+}
+
+/*
+ * That we decode a file handle without having to pass a pidfd.
+ */
+TEST_F(file_handle, decode_purely_based_on_file_handle)
+{
+ int mnt_id;
+ struct file_handle *fh;
+ int pidfd = -EBADF;
+ struct stat st1, st2;
+
+ fh = malloc(sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ ASSERT_NE(fh, NULL);
+ memset(fh, 0, sizeof(struct file_handle) + MAX_HANDLE_SZ);
+ fh->handle_bytes = MAX_HANDLE_SZ;
+
+ ASSERT_EQ(name_to_handle_at(self->child_pidfd1, "", fh, &mnt_id, AT_EMPTY_PATH), 0);
+
+ ASSERT_EQ(fstat(self->child_pidfd1, &st1), 0);
+
+ pidfd = open_by_handle_at(FD_PIDFS_ROOT, fh, 0);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+
+ pidfd = open_by_handle_at(FD_PIDFS_ROOT, fh, O_CLOEXEC);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+
+ pidfd = open_by_handle_at(FD_PIDFS_ROOT, fh, O_NONBLOCK);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+
+ pidfd = open_by_handle_at(self->pidfd, fh, 0);
+ ASSERT_GE(pidfd, 0);
+
+ ASSERT_EQ(fstat(pidfd, &st2), 0);
+ ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+
+ ASSERT_EQ(close(pidfd), 0);
+
+ pidfd = open_by_handle_at(-EBADF, fh, 0);
+ ASSERT_LT(pidfd, 0);
+
+ pidfd = open_by_handle_at(AT_FDCWD, fh, 0);
+ ASSERT_LT(pidfd, 0);
+
+ free(fh);
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/pidfd/pidfd_getfd_test.c b/tools/testing/selftests/pidfd/pidfd_getfd_test.c
index cd51d547b751..ea45b37001b0 100644
--- a/tools/testing/selftests/pidfd/pidfd_getfd_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_getfd_test.c
@@ -19,7 +19,7 @@
#include <linux/kcmp.h>
#include "pidfd.h"
-#include "../kselftest_harness.h"
+#include "kselftest_harness.h"
/*
* UNKNOWN_FD is an fd number that should never exist in the child, as it is
diff --git a/tools/testing/selftests/pidfd/pidfd_info_test.c b/tools/testing/selftests/pidfd/pidfd_info_test.c
new file mode 100644
index 000000000000..597012ed195f
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd_info_test.c
@@ -0,0 +1,767 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <linux/types.h>
+#include <poll.h>
+#include <pthread.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syscall.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <linux/kcmp.h>
+#include <sys/stat.h>
+
+#include "pidfd.h"
+#include "kselftest_harness.h"
+
+FIXTURE(pidfd_info)
+{
+ pid_t child_pid1;
+ int child_pidfd1;
+
+ pid_t child_pid2;
+ int child_pidfd2;
+
+ pid_t child_pid3;
+ int child_pidfd3;
+
+ pid_t child_pid4;
+ int child_pidfd4;
+};
+
+FIXTURE_SETUP(pidfd_info)
+{
+ int ret;
+ int ipc_sockets[2];
+ char c;
+
+ ret = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
+ EXPECT_EQ(ret, 0);
+
+ self->child_pid1 = create_child(&self->child_pidfd1, 0);
+ EXPECT_GE(self->child_pid1, 0);
+
+ if (self->child_pid1 == 0) {
+ close(ipc_sockets[0]);
+
+ if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+ _exit(EXIT_FAILURE);
+
+ close(ipc_sockets[1]);
+
+ pause();
+ _exit(EXIT_SUCCESS);
+ }
+
+ EXPECT_EQ(close(ipc_sockets[1]), 0);
+ ASSERT_EQ(read_nointr(ipc_sockets[0], &c, 1), 1);
+ EXPECT_EQ(close(ipc_sockets[0]), 0);
+
+ /* SIGKILL but don't reap. */
+ EXPECT_EQ(sys_pidfd_send_signal(self->child_pidfd1, SIGKILL, NULL, 0), 0);
+
+ ret = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
+ EXPECT_EQ(ret, 0);
+
+ self->child_pid2 = create_child(&self->child_pidfd2, 0);
+ EXPECT_GE(self->child_pid2, 0);
+
+ if (self->child_pid2 == 0) {
+ close(ipc_sockets[0]);
+
+ if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+ _exit(EXIT_FAILURE);
+
+ close(ipc_sockets[1]);
+
+ pause();
+ _exit(EXIT_SUCCESS);
+ }
+
+ EXPECT_EQ(close(ipc_sockets[1]), 0);
+ ASSERT_EQ(read_nointr(ipc_sockets[0], &c, 1), 1);
+ EXPECT_EQ(close(ipc_sockets[0]), 0);
+
+ /* SIGKILL and reap. */
+ EXPECT_EQ(sys_pidfd_send_signal(self->child_pidfd2, SIGKILL, NULL, 0), 0);
+ EXPECT_EQ(sys_waitid(P_PID, self->child_pid2, NULL, WEXITED), 0);
+
+ self->child_pid3 = create_child(&self->child_pidfd3, CLONE_NEWUSER | CLONE_NEWPID);
+ EXPECT_GE(self->child_pid3, 0);
+
+ if (self->child_pid3 == 0)
+ _exit(EXIT_SUCCESS);
+
+ self->child_pid4 = create_child(&self->child_pidfd4, CLONE_NEWUSER | CLONE_NEWPID);
+ EXPECT_GE(self->child_pid4, 0);
+
+ if (self->child_pid4 == 0)
+ _exit(EXIT_SUCCESS);
+
+ EXPECT_EQ(sys_waitid(P_PID, self->child_pid4, NULL, WEXITED), 0);
+}
+
+FIXTURE_TEARDOWN(pidfd_info)
+{
+ sys_pidfd_send_signal(self->child_pidfd1, SIGKILL, NULL, 0);
+ if (self->child_pidfd1 >= 0)
+ EXPECT_EQ(0, close(self->child_pidfd1));
+
+ sys_waitid(P_PID, self->child_pid1, NULL, WEXITED);
+
+ sys_pidfd_send_signal(self->child_pidfd2, SIGKILL, NULL, 0);
+ if (self->child_pidfd2 >= 0)
+ EXPECT_EQ(0, close(self->child_pidfd2));
+
+ sys_waitid(P_PID, self->child_pid2, NULL, WEXITED);
+ sys_waitid(P_PID, self->child_pid3, NULL, WEXITED);
+ sys_waitid(P_PID, self->child_pid4, NULL, WEXITED);
+}
+
+TEST_F(pidfd_info, sigkill_exit)
+{
+ struct pidfd_info info = {
+ .mask = PIDFD_INFO_CGROUPID,
+ };
+
+ /* Process has exited but not been reaped so this must work. */
+ ASSERT_EQ(ioctl(self->child_pidfd1, PIDFD_GET_INFO, &info), 0);
+
+ info.mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT;
+ ASSERT_EQ(ioctl(self->child_pidfd1, PIDFD_GET_INFO, &info), 0);
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_CREDS));
+ /* Process has exited but not been reaped, so no PIDFD_INFO_EXIT information yet. */
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_EXIT));
+}
+
+TEST_F(pidfd_info, sigkill_reaped)
+{
+ struct pidfd_info info = {
+ .mask = PIDFD_INFO_CGROUPID,
+ };
+
+ /* Process has already been reaped and PIDFD_INFO_EXIT hasn't been set. */
+ ASSERT_NE(ioctl(self->child_pidfd2, PIDFD_GET_INFO, &info), 0);
+ ASSERT_EQ(errno, ESRCH);
+
+ info.mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT;
+ ASSERT_EQ(ioctl(self->child_pidfd2, PIDFD_GET_INFO, &info), 0);
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_CREDS));
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_EXIT));
+ ASSERT_TRUE(WIFSIGNALED(info.exit_code));
+ ASSERT_EQ(WTERMSIG(info.exit_code), SIGKILL);
+}
+
+TEST_F(pidfd_info, success_exit)
+{
+ struct pidfd_info info = {
+ .mask = PIDFD_INFO_CGROUPID,
+ };
+
+ /* Process has exited but not been reaped so this must work. */
+ ASSERT_EQ(ioctl(self->child_pidfd3, PIDFD_GET_INFO, &info), 0);
+
+ info.mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT;
+ ASSERT_EQ(ioctl(self->child_pidfd3, PIDFD_GET_INFO, &info), 0);
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_CREDS));
+ /* Process has exited but not been reaped, so no PIDFD_INFO_EXIT information yet. */
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_EXIT));
+}
+
+TEST_F(pidfd_info, success_reaped)
+{
+ struct pidfd_info info = {
+ .mask = PIDFD_INFO_CGROUPID,
+ };
+
+ /* Process has already been reaped and PIDFD_INFO_EXIT hasn't been set. */
+ ASSERT_NE(ioctl(self->child_pidfd4, PIDFD_GET_INFO, &info), 0);
+ ASSERT_EQ(errno, ESRCH);
+
+ info.mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT;
+ ASSERT_EQ(ioctl(self->child_pidfd4, PIDFD_GET_INFO, &info), 0);
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_CREDS));
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_EXIT));
+ ASSERT_TRUE(WIFEXITED(info.exit_code));
+ ASSERT_EQ(WEXITSTATUS(info.exit_code), 0);
+}
+
+TEST_F(pidfd_info, success_reaped_poll)
+{
+ struct pidfd_info info = {
+ .mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT,
+ };
+ struct pollfd fds = {};
+ int nevents;
+
+ fds.events = POLLIN;
+ fds.fd = self->child_pidfd2;
+
+ nevents = poll(&fds, 1, -1);
+ ASSERT_EQ(nevents, 1);
+ ASSERT_TRUE(!!(fds.revents & POLLIN));
+ ASSERT_TRUE(!!(fds.revents & POLLHUP));
+
+ ASSERT_EQ(ioctl(self->child_pidfd2, PIDFD_GET_INFO, &info), 0);
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_CREDS));
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_EXIT));
+ ASSERT_TRUE(WIFSIGNALED(info.exit_code));
+ ASSERT_EQ(WTERMSIG(info.exit_code), SIGKILL);
+}
+
+static void *pidfd_info_pause_thread(void *arg)
+{
+ pid_t pid_thread = gettid();
+ int ipc_socket = *(int *)arg;
+
+ /* Inform the grand-parent what the tid of this thread is. */
+ if (write_nointr(ipc_socket, &pid_thread, sizeof(pid_thread)) != sizeof(pid_thread))
+ return NULL;
+
+ close(ipc_socket);
+
+ /* Sleep until we're killed. */
+ pause();
+ return NULL;
+}
+
+TEST_F(pidfd_info, thread_group)
+{
+ pid_t pid_leader, pid_poller, pid_thread;
+ pthread_t thread;
+ int nevents, pidfd_leader, pidfd_thread, pidfd_leader_thread, ret;
+ int ipc_sockets[2];
+ struct pollfd fds = {};
+ struct pidfd_info info = {
+ .mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT,
+ }, info2;
+
+ ret = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
+ EXPECT_EQ(ret, 0);
+
+ pid_leader = create_child(&pidfd_leader, 0);
+ EXPECT_GE(pid_leader, 0);
+
+ if (pid_leader == 0) {
+ close(ipc_sockets[0]);
+
+ /* The thread will outlive the thread-group leader. */
+ if (pthread_create(&thread, NULL, pidfd_info_pause_thread, &ipc_sockets[1]))
+ syscall(__NR_exit, EXIT_FAILURE);
+
+ /* Make the thread-group leader exit prematurely. */
+ syscall(__NR_exit, EXIT_SUCCESS);
+ }
+
+ /*
+ * Opening a PIDFD_THREAD aka thread-specific pidfd based on a
+ * thread-group leader must succeed.
+ */
+ pidfd_leader_thread = sys_pidfd_open(pid_leader, PIDFD_THREAD);
+ ASSERT_GE(pidfd_leader_thread, 0);
+
+ pid_poller = fork();
+ ASSERT_GE(pid_poller, 0);
+ if (pid_poller == 0) {
+ /*
+ * We can't poll and wait for the old thread-group
+ * leader to exit using a thread-specific pidfd. The
+ * thread-group leader exited prematurely and
+ * notification is delayed until all subthreads have
+ * exited.
+ */
+ fds.events = POLLIN;
+ fds.fd = pidfd_leader_thread;
+ nevents = poll(&fds, 1, 10000 /* wait 5 seconds */);
+ if (nevents != 0)
+ _exit(EXIT_FAILURE);
+ if (fds.revents & POLLIN)
+ _exit(EXIT_FAILURE);
+ if (fds.revents & POLLHUP)
+ _exit(EXIT_FAILURE);
+ _exit(EXIT_SUCCESS);
+ }
+
+ /* Retrieve the tid of the thread. */
+ EXPECT_EQ(close(ipc_sockets[1]), 0);
+ ASSERT_EQ(read_nointr(ipc_sockets[0], &pid_thread, sizeof(pid_thread)), sizeof(pid_thread));
+ EXPECT_EQ(close(ipc_sockets[0]), 0);
+
+ /* Opening a thread as a thread-group leader must fail. */
+ pidfd_thread = sys_pidfd_open(pid_thread, 0);
+ ASSERT_LT(pidfd_thread, 0);
+ ASSERT_EQ(errno, ENOENT);
+
+ /* Opening a thread as a PIDFD_THREAD must succeed. */
+ pidfd_thread = sys_pidfd_open(pid_thread, PIDFD_THREAD);
+ ASSERT_GE(pidfd_thread, 0);
+
+ ASSERT_EQ(wait_for_pid(pid_poller), 0);
+
+ /*
+ * Note that pidfd_leader is a thread-group pidfd, so polling on it
+ * would only notify us once all thread in the thread-group have
+ * exited. So we can't poll before we have taken down the whole
+ * thread-group.
+ */
+
+ /* Get PIDFD_GET_INFO using the thread-group leader pidfd. */
+ ASSERT_EQ(ioctl(pidfd_leader, PIDFD_GET_INFO, &info), 0);
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_CREDS));
+ /* Process has exited but not been reaped, so no PIDFD_INFO_EXIT information yet. */
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_EXIT));
+ ASSERT_EQ(info.pid, pid_leader);
+
+ /*
+ * Now retrieve the same info using the thread specific pidfd
+ * for the thread-group leader.
+ */
+ info2.mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT;
+ ASSERT_EQ(ioctl(pidfd_leader_thread, PIDFD_GET_INFO, &info2), 0);
+ ASSERT_TRUE(!!(info2.mask & PIDFD_INFO_CREDS));
+ /* Process has exited but not been reaped, so no PIDFD_INFO_EXIT information yet. */
+ ASSERT_FALSE(!!(info2.mask & PIDFD_INFO_EXIT));
+ ASSERT_EQ(info2.pid, pid_leader);
+
+ /* Now try the thread-specific pidfd. */
+ ASSERT_EQ(ioctl(pidfd_thread, PIDFD_GET_INFO, &info), 0);
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_CREDS));
+ /* The thread hasn't exited, so no PIDFD_INFO_EXIT information yet. */
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_EXIT));
+ ASSERT_EQ(info.pid, pid_thread);
+
+ /*
+ * Take down the whole thread-group. The thread-group leader
+ * exited successfully but the thread will now be SIGKILLed.
+ * This must be reflected in the recorded exit information.
+ */
+ EXPECT_EQ(sys_pidfd_send_signal(pidfd_leader, SIGKILL, NULL, 0), 0);
+ EXPECT_EQ(sys_waitid(P_PIDFD, pidfd_leader, NULL, WEXITED), 0);
+
+ fds.events = POLLIN;
+ fds.fd = pidfd_leader;
+ nevents = poll(&fds, 1, -1);
+ ASSERT_EQ(nevents, 1);
+ ASSERT_TRUE(!!(fds.revents & POLLIN));
+ /* The thread-group leader has been reaped. */
+ ASSERT_TRUE(!!(fds.revents & POLLHUP));
+
+ /*
+ * Retrieve exit information for the thread-group leader via the
+ * thread-group leader pidfd.
+ */
+ info.mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT;
+ ASSERT_EQ(ioctl(pidfd_leader, PIDFD_GET_INFO, &info), 0);
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_CREDS));
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_EXIT));
+ /* Even though the thread-group exited successfully it will still report the group exit code. */
+ ASSERT_TRUE(WIFSIGNALED(info.exit_code));
+ ASSERT_EQ(WTERMSIG(info.exit_code), SIGKILL);
+
+ /*
+ * Retrieve exit information for the thread-group leader via the
+ * thread-specific pidfd.
+ */
+ info2.mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT;
+ ASSERT_EQ(ioctl(pidfd_leader_thread, PIDFD_GET_INFO, &info2), 0);
+ ASSERT_FALSE(!!(info2.mask & PIDFD_INFO_CREDS));
+ ASSERT_TRUE(!!(info2.mask & PIDFD_INFO_EXIT));
+
+ /* Even though the thread-group exited successfully it will still report the group exit code. */
+ ASSERT_TRUE(WIFSIGNALED(info2.exit_code));
+ ASSERT_EQ(WTERMSIG(info2.exit_code), SIGKILL);
+
+ /* Retrieve exit information for the thread. */
+ info.mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT;
+ ASSERT_EQ(ioctl(pidfd_thread, PIDFD_GET_INFO, &info), 0);
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_CREDS));
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_EXIT));
+
+ /* The thread got SIGKILLed. */
+ ASSERT_TRUE(WIFSIGNALED(info.exit_code));
+ ASSERT_EQ(WTERMSIG(info.exit_code), SIGKILL);
+
+ EXPECT_EQ(close(pidfd_leader), 0);
+ EXPECT_EQ(close(pidfd_thread), 0);
+}
+
+static void *pidfd_info_thread_exec(void *arg)
+{
+ pid_t pid_thread = gettid();
+ int ipc_socket = *(int *)arg;
+
+ /* Inform the grand-parent what the tid of this thread is. */
+ if (write_nointr(ipc_socket, &pid_thread, sizeof(pid_thread)) != sizeof(pid_thread))
+ return NULL;
+
+ if (read_nointr(ipc_socket, &pid_thread, sizeof(pid_thread)) != sizeof(pid_thread))
+ return NULL;
+
+ close(ipc_socket);
+
+ sys_execveat(AT_FDCWD, "pidfd_exec_helper", NULL, NULL, 0);
+ return NULL;
+}
+
+TEST_F(pidfd_info, thread_group_exec)
+{
+ pid_t pid_leader, pid_poller, pid_thread;
+ pthread_t thread;
+ int nevents, pidfd_leader, pidfd_leader_thread, pidfd_thread, ret;
+ int ipc_sockets[2];
+ struct pollfd fds = {};
+ struct pidfd_info info = {
+ .mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT,
+ };
+
+ ret = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
+ EXPECT_EQ(ret, 0);
+
+ pid_leader = create_child(&pidfd_leader, 0);
+ EXPECT_GE(pid_leader, 0);
+
+ if (pid_leader == 0) {
+ close(ipc_sockets[0]);
+
+ /* The thread will outlive the thread-group leader. */
+ if (pthread_create(&thread, NULL, pidfd_info_thread_exec, &ipc_sockets[1]))
+ syscall(__NR_exit, EXIT_FAILURE);
+
+ /* Make the thread-group leader exit prematurely. */
+ syscall(__NR_exit, EXIT_SUCCESS);
+ }
+
+ /* Open a thread-specific pidfd for the thread-group leader. */
+ pidfd_leader_thread = sys_pidfd_open(pid_leader, PIDFD_THREAD);
+ ASSERT_GE(pidfd_leader_thread, 0);
+
+ pid_poller = fork();
+ ASSERT_GE(pid_poller, 0);
+ if (pid_poller == 0) {
+ /*
+ * We can't poll and wait for the old thread-group
+ * leader to exit using a thread-specific pidfd. The
+ * thread-group leader exited prematurely and
+ * notification is delayed until all subthreads have
+ * exited.
+ *
+ * When the thread has execed it will taken over the old
+ * thread-group leaders struct pid. Calling poll after
+ * the thread execed will thus block again because a new
+ * thread-group has started.
+ */
+ fds.events = POLLIN;
+ fds.fd = pidfd_leader_thread;
+ nevents = poll(&fds, 1, 10000 /* wait 5 seconds */);
+ if (nevents != 0)
+ _exit(EXIT_FAILURE);
+ if (fds.revents & POLLIN)
+ _exit(EXIT_FAILURE);
+ if (fds.revents & POLLHUP)
+ _exit(EXIT_FAILURE);
+ _exit(EXIT_SUCCESS);
+ }
+
+ /* Retrieve the tid of the thread. */
+ EXPECT_EQ(close(ipc_sockets[1]), 0);
+ ASSERT_EQ(read_nointr(ipc_sockets[0], &pid_thread, sizeof(pid_thread)), sizeof(pid_thread));
+
+ /* Opening a thread as a PIDFD_THREAD must succeed. */
+ pidfd_thread = sys_pidfd_open(pid_thread, PIDFD_THREAD);
+ ASSERT_GE(pidfd_thread, 0);
+
+ /* Now that we've opened a thread-specific pidfd the thread can exec. */
+ ASSERT_EQ(write_nointr(ipc_sockets[0], &pid_thread, sizeof(pid_thread)), sizeof(pid_thread));
+ EXPECT_EQ(close(ipc_sockets[0]), 0);
+
+ ASSERT_EQ(wait_for_pid(pid_poller), 0);
+
+ /* Wait until the kernel has SIGKILLed the thread. */
+ fds.events = POLLHUP;
+ fds.fd = pidfd_thread;
+ nevents = poll(&fds, 1, -1);
+ ASSERT_EQ(nevents, 1);
+ /* The thread has been reaped. */
+ ASSERT_TRUE(!!(fds.revents & POLLHUP));
+
+ /* Retrieve thread-specific exit info from pidfd. */
+ ASSERT_EQ(ioctl(pidfd_thread, PIDFD_GET_INFO, &info), 0);
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_CREDS));
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_EXIT));
+ /*
+ * While the kernel will have SIGKILLed the whole thread-group
+ * during exec it will cause the individual threads to exit
+ * cleanly.
+ */
+ ASSERT_TRUE(WIFEXITED(info.exit_code));
+ ASSERT_EQ(WEXITSTATUS(info.exit_code), 0);
+
+ /*
+ * The thread-group leader is still alive, the thread has taken
+ * over its struct pid and thus its pid number.
+ */
+ info.mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT;
+ ASSERT_EQ(ioctl(pidfd_leader, PIDFD_GET_INFO, &info), 0);
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_CREDS));
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_EXIT));
+ ASSERT_EQ(info.pid, pid_leader);
+
+ /* Take down the thread-group leader. */
+ EXPECT_EQ(sys_pidfd_send_signal(pidfd_leader, SIGKILL, NULL, 0), 0);
+
+ /*
+ * Afte the exec we're dealing with an empty thread-group so now
+ * we must see an exit notification on the thread-specific pidfd
+ * for the thread-group leader as there's no subthread that can
+ * revive the struct pid.
+ */
+ fds.events = POLLIN;
+ fds.fd = pidfd_leader_thread;
+ nevents = poll(&fds, 1, -1);
+ ASSERT_EQ(nevents, 1);
+ ASSERT_TRUE(!!(fds.revents & POLLIN));
+ ASSERT_FALSE(!!(fds.revents & POLLHUP));
+
+ EXPECT_EQ(sys_waitid(P_PIDFD, pidfd_leader, NULL, WEXITED), 0);
+
+ /* Retrieve exit information for the thread-group leader. */
+ info.mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT;
+ ASSERT_EQ(ioctl(pidfd_leader, PIDFD_GET_INFO, &info), 0);
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_CREDS));
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_EXIT));
+
+ EXPECT_EQ(close(pidfd_leader), 0);
+ EXPECT_EQ(close(pidfd_thread), 0);
+}
+
+static void *pidfd_info_thread_exec_sane(void *arg)
+{
+ pid_t pid_thread = gettid();
+ int ipc_socket = *(int *)arg;
+
+ /* Inform the grand-parent what the tid of this thread is. */
+ if (write_nointr(ipc_socket, &pid_thread, sizeof(pid_thread)) != sizeof(pid_thread))
+ return NULL;
+
+ if (read_nointr(ipc_socket, &pid_thread, sizeof(pid_thread)) != sizeof(pid_thread))
+ return NULL;
+
+ close(ipc_socket);
+
+ sys_execveat(AT_FDCWD, "pidfd_exec_helper", NULL, NULL, 0);
+ return NULL;
+}
+
+TEST_F(pidfd_info, thread_group_exec_thread)
+{
+ pid_t pid_leader, pid_poller, pid_thread;
+ pthread_t thread;
+ int nevents, pidfd_leader, pidfd_leader_thread, pidfd_thread, ret;
+ int ipc_sockets[2];
+ struct pollfd fds = {};
+ struct pidfd_info info = {
+ .mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT,
+ };
+
+ ret = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
+ EXPECT_EQ(ret, 0);
+
+ pid_leader = create_child(&pidfd_leader, 0);
+ EXPECT_GE(pid_leader, 0);
+
+ if (pid_leader == 0) {
+ close(ipc_sockets[0]);
+
+ /* The thread will outlive the thread-group leader. */
+ if (pthread_create(&thread, NULL, pidfd_info_thread_exec_sane, &ipc_sockets[1]))
+ syscall(__NR_exit, EXIT_FAILURE);
+
+ /*
+ * Pause the thread-group leader. It will be killed once
+ * the subthread execs.
+ */
+ pause();
+ syscall(__NR_exit, EXIT_SUCCESS);
+ }
+
+ /* Retrieve the tid of the thread. */
+ EXPECT_EQ(close(ipc_sockets[1]), 0);
+ ASSERT_EQ(read_nointr(ipc_sockets[0], &pid_thread, sizeof(pid_thread)), sizeof(pid_thread));
+
+ /* Opening a thread as a PIDFD_THREAD must succeed. */
+ pidfd_thread = sys_pidfd_open(pid_thread, PIDFD_THREAD);
+ ASSERT_GE(pidfd_thread, 0);
+
+ /* Open a thread-specific pidfd for the thread-group leader. */
+ pidfd_leader_thread = sys_pidfd_open(pid_leader, PIDFD_THREAD);
+ ASSERT_GE(pidfd_leader_thread, 0);
+
+ pid_poller = fork();
+ ASSERT_GE(pid_poller, 0);
+ if (pid_poller == 0) {
+ /*
+ * The subthread will now exec. The struct pid of the old
+ * thread-group leader will be assumed by the subthread which
+ * becomes the new thread-group leader. So no exit notification
+ * must be generated. Wait for 5 seconds and call it a success
+ * if no notification has been received.
+ */
+ fds.events = POLLIN;
+ fds.fd = pidfd_leader_thread;
+ nevents = poll(&fds, 1, 10000 /* wait 5 seconds */);
+ if (nevents != 0)
+ _exit(EXIT_FAILURE);
+ if (fds.revents & POLLIN)
+ _exit(EXIT_FAILURE);
+ if (fds.revents & POLLHUP)
+ _exit(EXIT_FAILURE);
+ _exit(EXIT_SUCCESS);
+ }
+
+ /* Now that we've opened a thread-specific pidfd the thread can exec. */
+ ASSERT_EQ(write_nointr(ipc_sockets[0], &pid_thread, sizeof(pid_thread)), sizeof(pid_thread));
+ EXPECT_EQ(close(ipc_sockets[0]), 0);
+ ASSERT_EQ(wait_for_pid(pid_poller), 0);
+
+ /* Wait until the kernel has SIGKILLed the thread. */
+ fds.events = POLLHUP;
+ fds.fd = pidfd_thread;
+ nevents = poll(&fds, 1, -1);
+ ASSERT_EQ(nevents, 1);
+ /* The thread has been reaped. */
+ ASSERT_TRUE(!!(fds.revents & POLLHUP));
+
+ /* Retrieve thread-specific exit info from pidfd. */
+ ASSERT_EQ(ioctl(pidfd_thread, PIDFD_GET_INFO, &info), 0);
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_CREDS));
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_EXIT));
+ /*
+ * While the kernel will have SIGKILLed the whole thread-group
+ * during exec it will cause the individual threads to exit
+ * cleanly.
+ */
+ ASSERT_TRUE(WIFEXITED(info.exit_code));
+ ASSERT_EQ(WEXITSTATUS(info.exit_code), 0);
+
+ /*
+ * The thread-group leader is still alive, the thread has taken
+ * over its struct pid and thus its pid number.
+ */
+ info.mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT;
+ ASSERT_EQ(ioctl(pidfd_leader, PIDFD_GET_INFO, &info), 0);
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_CREDS));
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_EXIT));
+ ASSERT_EQ(info.pid, pid_leader);
+
+ /* Take down the thread-group leader. */
+ EXPECT_EQ(sys_pidfd_send_signal(pidfd_leader, SIGKILL, NULL, 0), 0);
+
+ /*
+ * Afte the exec we're dealing with an empty thread-group so now
+ * we must see an exit notification on the thread-specific pidfd
+ * for the thread-group leader as there's no subthread that can
+ * revive the struct pid.
+ */
+ fds.events = POLLIN;
+ fds.fd = pidfd_leader_thread;
+ nevents = poll(&fds, 1, -1);
+ ASSERT_EQ(nevents, 1);
+ ASSERT_TRUE(!!(fds.revents & POLLIN));
+ ASSERT_FALSE(!!(fds.revents & POLLHUP));
+
+ EXPECT_EQ(sys_waitid(P_PIDFD, pidfd_leader, NULL, WEXITED), 0);
+
+ /* Retrieve exit information for the thread-group leader. */
+ info.mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT;
+ ASSERT_EQ(ioctl(pidfd_leader, PIDFD_GET_INFO, &info), 0);
+ ASSERT_FALSE(!!(info.mask & PIDFD_INFO_CREDS));
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_EXIT));
+
+ EXPECT_EQ(close(pidfd_leader), 0);
+ EXPECT_EQ(close(pidfd_thread), 0);
+}
+
+/*
+ * Test: PIDFD_INFO_SUPPORTED_MASK field
+ *
+ * Verify that when PIDFD_INFO_SUPPORTED_MASK is requested, the kernel
+ * returns the supported_mask field indicating which flags the kernel supports.
+ */
+TEST(supported_mask_field)
+{
+ struct pidfd_info info = {
+ .mask = PIDFD_INFO_SUPPORTED_MASK,
+ };
+ int pidfd;
+ pid_t pid;
+
+ pid = create_child(&pidfd, 0);
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0)
+ pause();
+
+ /* Request supported_mask field */
+ ASSERT_EQ(ioctl(pidfd, PIDFD_GET_INFO, &info), 0);
+
+ /* Verify PIDFD_INFO_SUPPORTED_MASK is set in the reply */
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_SUPPORTED_MASK));
+
+ /* Verify supported_mask contains expected flags */
+ ASSERT_TRUE(!!(info.supported_mask & PIDFD_INFO_PID));
+ ASSERT_TRUE(!!(info.supported_mask & PIDFD_INFO_CREDS));
+ ASSERT_TRUE(!!(info.supported_mask & PIDFD_INFO_CGROUPID));
+ ASSERT_TRUE(!!(info.supported_mask & PIDFD_INFO_EXIT));
+ ASSERT_TRUE(!!(info.supported_mask & PIDFD_INFO_COREDUMP));
+ ASSERT_TRUE(!!(info.supported_mask & PIDFD_INFO_SUPPORTED_MASK));
+ ASSERT_TRUE(!!(info.supported_mask & PIDFD_INFO_COREDUMP_SIGNAL));
+ ASSERT_TRUE(!!(info.supported_mask & PIDFD_INFO_COREDUMP_CODE));
+
+ /* Clean up */
+ sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0);
+ sys_waitid(P_PIDFD, pidfd, NULL, WEXITED);
+ close(pidfd);
+}
+
+/*
+ * Test: PIDFD_INFO_SUPPORTED_MASK always available
+ *
+ * Verify that supported_mask is returned even when other fields are requested.
+ */
+TEST(supported_mask_with_other_fields)
+{
+ struct pidfd_info info = {
+ .mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_SUPPORTED_MASK,
+ };
+ int pidfd;
+ pid_t pid;
+
+ pid = create_child(&pidfd, 0);
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0)
+ pause();
+
+ ASSERT_EQ(ioctl(pidfd, PIDFD_GET_INFO, &info), 0);
+
+ /* Both fields should be present */
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_CGROUPID));
+ ASSERT_TRUE(!!(info.mask & PIDFD_INFO_SUPPORTED_MASK));
+ ASSERT_NE(info.supported_mask, 0);
+
+ /* Clean up */
+ sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0);
+ sys_waitid(P_PIDFD, pidfd, NULL, WEXITED);
+ close(pidfd);
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/pidfd/pidfd_open_test.c b/tools/testing/selftests/pidfd/pidfd_open_test.c
index ce413a221bac..318e6f09c8e0 100644
--- a/tools/testing/selftests/pidfd/pidfd_open_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_open_test.c
@@ -20,33 +20,7 @@
#include <unistd.h>
#include "pidfd.h"
-#include "../kselftest.h"
-
-#ifndef PIDFS_IOCTL_MAGIC
-#define PIDFS_IOCTL_MAGIC 0xFF
-#endif
-
-#ifndef PIDFD_GET_INFO
-#define PIDFD_GET_INFO _IOWR(PIDFS_IOCTL_MAGIC, 11, struct pidfd_info)
-#define PIDFD_INFO_CGROUPID (1UL << 0)
-
-struct pidfd_info {
- __u64 request_mask;
- __u64 cgroupid;
- __u32 pid;
- __u32 tgid;
- __u32 ppid;
- __u32 ruid;
- __u32 rgid;
- __u32 euid;
- __u32 egid;
- __u32 suid;
- __u32 sgid;
- __u32 fsuid;
- __u32 fsgid;
- __u32 spare0[1];
-};
-#endif
+#include "kselftest.h"
static int safe_int(const char *numstr, int *converted)
{
@@ -148,7 +122,7 @@ out:
int main(int argc, char **argv)
{
struct pidfd_info info = {
- .request_mask = PIDFD_INFO_CGROUPID,
+ .mask = PIDFD_INFO_CGROUPID,
};
int pidfd = -1, ret = 1;
pid_t pid;
@@ -227,7 +201,7 @@ int main(int argc, char **argv)
getegid(), info.sgid);
goto on_error;
}
- if ((info.request_mask & PIDFD_INFO_CGROUPID) && info.cgroupid == 0) {
+ if ((info.mask & PIDFD_INFO_CGROUPID) && info.cgroupid == 0) {
ksft_print_msg("cgroupid should not be 0 when PIDFD_INFO_CGROUPID is set\n");
goto on_error;
}
diff --git a/tools/testing/selftests/pidfd/pidfd_poll_test.c b/tools/testing/selftests/pidfd/pidfd_poll_test.c
index 55d74a50358f..232304f818c7 100644
--- a/tools/testing/selftests/pidfd/pidfd_poll_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_poll_test.c
@@ -14,7 +14,7 @@
#include <unistd.h>
#include "pidfd.h"
-#include "../kselftest.h"
+#include "kselftest.h"
static bool timeout;
diff --git a/tools/testing/selftests/pidfd/pidfd_setattr_test.c b/tools/testing/selftests/pidfd/pidfd_setattr_test.c
new file mode 100644
index 000000000000..e8562a2992f3
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd_setattr_test.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <linux/types.h>
+#include <poll.h>
+#include <pthread.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syscall.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <linux/kcmp.h>
+#include <sys/stat.h>
+#include <sys/xattr.h>
+
+#include "pidfd.h"
+#include "kselftest_harness.h"
+
+FIXTURE(pidfs_setattr)
+{
+ pid_t child_pid;
+ int child_pidfd;
+};
+
+FIXTURE_SETUP(pidfs_setattr)
+{
+ self->child_pid = create_child(&self->child_pidfd, CLONE_NEWUSER | CLONE_NEWPID);
+ EXPECT_GE(self->child_pid, 0);
+
+ if (self->child_pid == 0)
+ _exit(EXIT_SUCCESS);
+}
+
+FIXTURE_TEARDOWN(pidfs_setattr)
+{
+ sys_waitid(P_PID, self->child_pid, NULL, WEXITED);
+ EXPECT_EQ(close(self->child_pidfd), 0);
+}
+
+TEST_F(pidfs_setattr, no_chown)
+{
+ ASSERT_LT(fchown(self->child_pidfd, 1234, 5678), 0);
+ ASSERT_EQ(errno, EOPNOTSUPP);
+}
+
+TEST_F(pidfs_setattr, no_chmod)
+{
+ ASSERT_LT(fchmod(self->child_pidfd, 0777), 0);
+ ASSERT_EQ(errno, EOPNOTSUPP);
+}
+
+TEST_F(pidfs_setattr, no_exec)
+{
+ char *const argv[] = { NULL };
+ char *const envp[] = { NULL };
+
+ ASSERT_LT(execveat(self->child_pidfd, "", argv, envp, AT_EMPTY_PATH), 0);
+ ASSERT_EQ(errno, EACCES);
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/pidfd/pidfd_setns_test.c b/tools/testing/selftests/pidfd/pidfd_setns_test.c
index 7c2a4349170a..107edecff224 100644
--- a/tools/testing/selftests/pidfd/pidfd_setns_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_setns_test.c
@@ -16,55 +16,9 @@
#include <unistd.h>
#include <sys/socket.h>
#include <sys/stat.h>
-#include <linux/ioctl.h>
#include "pidfd.h"
-#include "../clone3/clone3_selftests.h"
-#include "../kselftest_harness.h"
-
-#ifndef PIDFS_IOCTL_MAGIC
-#define PIDFS_IOCTL_MAGIC 0xFF
-#endif
-
-#ifndef PIDFD_GET_CGROUP_NAMESPACE
-#define PIDFD_GET_CGROUP_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 1)
-#endif
-
-#ifndef PIDFD_GET_IPC_NAMESPACE
-#define PIDFD_GET_IPC_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 2)
-#endif
-
-#ifndef PIDFD_GET_MNT_NAMESPACE
-#define PIDFD_GET_MNT_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 3)
-#endif
-
-#ifndef PIDFD_GET_NET_NAMESPACE
-#define PIDFD_GET_NET_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 4)
-#endif
-
-#ifndef PIDFD_GET_PID_NAMESPACE
-#define PIDFD_GET_PID_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 5)
-#endif
-
-#ifndef PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE
-#define PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 6)
-#endif
-
-#ifndef PIDFD_GET_TIME_NAMESPACE
-#define PIDFD_GET_TIME_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 7)
-#endif
-
-#ifndef PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE
-#define PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 8)
-#endif
-
-#ifndef PIDFD_GET_USER_NAMESPACE
-#define PIDFD_GET_USER_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 9)
-#endif
-
-#ifndef PIDFD_GET_UTS_NAMESPACE
-#define PIDFD_GET_UTS_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 10)
-#endif
+#include "kselftest_harness.h"
enum {
PIDFD_NS_USER,
@@ -118,22 +72,6 @@ FIXTURE(current_nsset)
int child_pidfd_derived_nsfds2[PIDFD_NS_MAX];
};
-static int sys_waitid(int which, pid_t pid, int options)
-{
- return syscall(__NR_waitid, which, pid, NULL, options, NULL);
-}
-
-pid_t create_child(int *pidfd, unsigned flags)
-{
- struct __clone_args args = {
- .flags = CLONE_PIDFD | flags,
- .exit_signal = SIGCHLD,
- .pidfd = ptr_to_u64(pidfd),
- };
-
- return sys_clone3(&args, sizeof(struct clone_args));
-}
-
static bool switch_timens(void)
{
int fd, ret;
@@ -150,28 +88,6 @@ static bool switch_timens(void)
return ret == 0;
}
-static ssize_t read_nointr(int fd, void *buf, size_t count)
-{
- ssize_t ret;
-
- do {
- ret = read(fd, buf, count);
- } while (ret < 0 && errno == EINTR);
-
- return ret;
-}
-
-static ssize_t write_nointr(int fd, const void *buf, size_t count)
-{
- ssize_t ret;
-
- do {
- ret = write(fd, buf, count);
- } while (ret < 0 && errno == EINTR);
-
- return ret;
-}
-
FIXTURE_SETUP(current_nsset)
{
int i, proc_fd, ret;
@@ -229,7 +145,7 @@ FIXTURE_SETUP(current_nsset)
_exit(EXIT_SUCCESS);
}
- ASSERT_EQ(sys_waitid(P_PID, self->child_pid_exited, WEXITED | WNOWAIT), 0);
+ ASSERT_EQ(sys_waitid(P_PID, self->child_pid_exited, NULL, WEXITED | WNOWAIT), 0);
self->pidfd = sys_pidfd_open(self->pid, 0);
EXPECT_GE(self->pidfd, 0) {
@@ -432,9 +348,9 @@ FIXTURE_TEARDOWN(current_nsset)
EXPECT_EQ(0, close(self->child_pidfd1));
if (self->child_pidfd2 >= 0)
EXPECT_EQ(0, close(self->child_pidfd2));
- ASSERT_EQ(sys_waitid(P_PID, self->child_pid_exited, WEXITED), 0);
- ASSERT_EQ(sys_waitid(P_PID, self->child_pid1, WEXITED), 0);
- ASSERT_EQ(sys_waitid(P_PID, self->child_pid2, WEXITED), 0);
+ ASSERT_EQ(sys_waitid(P_PID, self->child_pid_exited, NULL, WEXITED), 0);
+ ASSERT_EQ(sys_waitid(P_PID, self->child_pid1, NULL, WEXITED), 0);
+ ASSERT_EQ(sys_waitid(P_PID, self->child_pid2, NULL, WEXITED), 0);
}
static int preserve_ns(const int pid, const char *ns)
diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c
index 9faa686f90e4..932cbd8caa77 100644
--- a/tools/testing/selftests/pidfd/pidfd_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_test.c
@@ -20,7 +20,7 @@
#include <unistd.h>
#include "pidfd.h"
-#include "../kselftest.h"
+#include "kselftest.h"
#define str(s) _str(s)
#define _str(s) #s
@@ -42,12 +42,41 @@ static pid_t pidfd_clone(int flags, int *pidfd, int (*fn)(void *))
#endif
}
-static int signal_received;
+static pthread_t signal_received;
static void set_signal_received_on_sigusr1(int sig)
{
if (sig == SIGUSR1)
- signal_received = 1;
+ signal_received = pthread_self();
+}
+
+static int send_signal(int pidfd)
+{
+ int ret = 0;
+
+ if (sys_pidfd_send_signal(pidfd, SIGUSR1, NULL, 0) < 0) {
+ ret = -EINVAL;
+ goto exit;
+ }
+
+ if (signal_received != pthread_self()) {
+ ret = -EINVAL;
+ goto exit;
+ }
+
+exit:
+ signal_received = 0;
+ return ret;
+}
+
+static void *send_signal_worker(void *arg)
+{
+ int pidfd = (int)(intptr_t)arg;
+ int ret;
+
+ /* We forward any errors for the caller to handle. */
+ ret = send_signal(pidfd);
+ return (void *)(intptr_t)ret;
}
/*
@@ -56,8 +85,11 @@ static void set_signal_received_on_sigusr1(int sig)
*/
static int test_pidfd_send_signal_simple_success(void)
{
- int pidfd, ret;
+ int pidfd;
const char *test_name = "pidfd_send_signal send SIGUSR1";
+ pthread_t thread;
+ void *thread_res;
+ int err;
if (!have_pidfd_send_signal) {
ksft_test_result_skip(
@@ -66,25 +98,45 @@ static int test_pidfd_send_signal_simple_success(void)
return 0;
}
+ signal(SIGUSR1, set_signal_received_on_sigusr1);
+
+ /* Try sending a signal to ourselves via /proc/self. */
pidfd = open("/proc/self", O_DIRECTORY | O_CLOEXEC);
if (pidfd < 0)
ksft_exit_fail_msg(
"%s test: Failed to open process file descriptor\n",
test_name);
+ err = send_signal(pidfd);
+ if (err)
+ ksft_exit_fail_msg(
+ "%s test: Error %d on sending pidfd signal\n",
+ test_name, err);
+ close(pidfd);
- signal(SIGUSR1, set_signal_received_on_sigusr1);
+ /* Now try the same thing only using PIDFD_SELF_THREAD_GROUP. */
+ err = send_signal(PIDFD_SELF_THREAD_GROUP);
+ if (err)
+ ksft_exit_fail_msg(
+ "%s test: Error %d on PIDFD_SELF_THREAD_GROUP signal\n",
+ test_name, err);
- ret = sys_pidfd_send_signal(pidfd, SIGUSR1, NULL, 0);
- close(pidfd);
- if (ret < 0)
- ksft_exit_fail_msg("%s test: Failed to send signal\n",
+ /*
+ * Now try the same thing in a thread and assert thread ID is equal to
+ * worker thread ID.
+ */
+ if (pthread_create(&thread, NULL, send_signal_worker,
+ (void *)(intptr_t)PIDFD_SELF_THREAD))
+ ksft_exit_fail_msg("%s test: Failed to create thread\n",
test_name);
-
- if (signal_received != 1)
- ksft_exit_fail_msg("%s test: Failed to receive signal\n",
+ if (pthread_join(thread, &thread_res))
+ ksft_exit_fail_msg("%s test: Failed to join thread\n",
test_name);
+ err = (int)(intptr_t)thread_res;
+ if (err)
+ ksft_exit_fail_msg(
+ "%s test: Error %d on PIDFD_SELF_THREAD signal\n",
+ test_name, err);
- signal_received = 0;
ksft_test_result_pass("%s test: Sent signal\n", test_name);
return 0;
}
@@ -497,7 +549,7 @@ static int child_poll_leader_exit_test(void *args)
pthread_create(&t2, NULL, test_pidfd_poll_leader_exit_thread, NULL);
/*
- * glibc exit calls exit_group syscall, so explicity call exit only
+ * glibc exit calls exit_group syscall, so explicitly call exit only
* so that only the group leader exits, leaving the threads alone.
*/
*child_exit_secs = time(NULL);
diff --git a/tools/testing/selftests/pidfd/pidfd_wait.c b/tools/testing/selftests/pidfd/pidfd_wait.c
index 0dcb8365ddc3..4bf702d62c1c 100644
--- a/tools/testing/selftests/pidfd/pidfd_wait.c
+++ b/tools/testing/selftests/pidfd/pidfd_wait.c
@@ -17,7 +17,7 @@
#include <unistd.h>
#include "pidfd.h"
-#include "../kselftest_harness.h"
+#include "kselftest_harness.h"
#define ptr_to_u64(ptr) ((__u64)((uintptr_t)(ptr)))
@@ -26,22 +26,11 @@
#define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__)
#endif
-static pid_t sys_clone3(struct clone_args *args)
-{
- return syscall(__NR_clone3, args, sizeof(struct clone_args));
-}
-
-static int sys_waitid(int which, pid_t pid, siginfo_t *info, int options,
- struct rusage *ru)
-{
- return syscall(__NR_waitid, which, pid, info, options, ru);
-}
-
TEST(wait_simple)
{
int pidfd = -1;
pid_t parent_tid = -1;
- struct clone_args args = {
+ struct __clone_args args = {
.parent_tid = ptr_to_u64(&parent_tid),
.pidfd = ptr_to_u64(&pidfd),
.flags = CLONE_PIDFD | CLONE_PARENT_SETTID,
@@ -55,7 +44,7 @@ TEST(wait_simple)
pidfd = open("/proc/self", O_DIRECTORY | O_RDONLY | O_CLOEXEC);
ASSERT_GE(pidfd, 0);
- pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL);
+ pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED);
ASSERT_NE(pid, 0);
EXPECT_EQ(close(pidfd), 0);
pidfd = -1;
@@ -63,18 +52,18 @@ TEST(wait_simple)
pidfd = open("/dev/null", O_RDONLY | O_CLOEXEC);
ASSERT_GE(pidfd, 0);
- pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL);
+ pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED);
ASSERT_NE(pid, 0);
EXPECT_EQ(close(pidfd), 0);
pidfd = -1;
- pid = sys_clone3(&args);
+ pid = sys_clone3(&args, sizeof(args));
ASSERT_GE(pid, 0);
if (pid == 0)
exit(EXIT_SUCCESS);
- pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL);
+ pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED);
ASSERT_GE(pid, 0);
ASSERT_EQ(WIFEXITED(info.si_status), true);
ASSERT_EQ(WEXITSTATUS(info.si_status), 0);
@@ -89,7 +78,7 @@ TEST(wait_states)
{
int pidfd = -1;
pid_t parent_tid = -1;
- struct clone_args args = {
+ struct __clone_args args = {
.parent_tid = ptr_to_u64(&parent_tid),
.pidfd = ptr_to_u64(&pidfd),
.flags = CLONE_PIDFD | CLONE_PARENT_SETTID,
@@ -102,7 +91,7 @@ TEST(wait_states)
};
ASSERT_EQ(pipe(pfd), 0);
- pid = sys_clone3(&args);
+ pid = sys_clone3(&args, sizeof(args));
ASSERT_GE(pid, 0);
if (pid == 0) {
@@ -117,28 +106,28 @@ TEST(wait_states)
}
close(pfd[0]);
- ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED, NULL), 0);
+ ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED), 0);
ASSERT_EQ(info.si_signo, SIGCHLD);
ASSERT_EQ(info.si_code, CLD_STOPPED);
ASSERT_EQ(info.si_pid, parent_tid);
ASSERT_EQ(sys_pidfd_send_signal(pidfd, SIGCONT, NULL, 0), 0);
- ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL), 0);
+ ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED), 0);
ASSERT_EQ(write(pfd[1], "C", 1), 1);
close(pfd[1]);
ASSERT_EQ(info.si_signo, SIGCHLD);
ASSERT_EQ(info.si_code, CLD_CONTINUED);
ASSERT_EQ(info.si_pid, parent_tid);
- ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WUNTRACED, NULL), 0);
+ ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WUNTRACED), 0);
ASSERT_EQ(info.si_signo, SIGCHLD);
ASSERT_EQ(info.si_code, CLD_STOPPED);
ASSERT_EQ(info.si_pid, parent_tid);
ASSERT_EQ(sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0), 0);
- ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL), 0);
+ ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WEXITED), 0);
ASSERT_EQ(info.si_signo, SIGCHLD);
ASSERT_EQ(info.si_code, CLD_KILLED);
ASSERT_EQ(info.si_pid, parent_tid);
@@ -151,7 +140,7 @@ TEST(wait_nonblock)
int pidfd;
unsigned int flags = 0;
pid_t parent_tid = -1;
- struct clone_args args = {
+ struct __clone_args args = {
.parent_tid = ptr_to_u64(&parent_tid),
.flags = CLONE_PARENT_SETTID,
.exit_signal = SIGCHLD,
@@ -173,12 +162,12 @@ TEST(wait_nonblock)
SKIP(return, "Skipping PIDFD_NONBLOCK test");
}
- ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL);
+ ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED);
ASSERT_LT(ret, 0);
ASSERT_EQ(errno, ECHILD);
EXPECT_EQ(close(pidfd), 0);
- pid = sys_clone3(&args);
+ pid = sys_clone3(&args, sizeof(args));
ASSERT_GE(pid, 0);
if (pid == 0) {
@@ -201,7 +190,7 @@ TEST(wait_nonblock)
* Callers need to see EAGAIN/EWOULDBLOCK with non-blocking pidfd when
* child processes exist but none have exited.
*/
- ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL);
+ ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED);
ASSERT_LT(ret, 0);
ASSERT_EQ(errno, EAGAIN);
@@ -210,19 +199,19 @@ TEST(wait_nonblock)
* WNOHANG raised explicitly when child processes exist but none have
* exited.
*/
- ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED | WNOHANG, NULL);
+ ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED | WNOHANG);
ASSERT_EQ(ret, 0);
ASSERT_EQ(fcntl(pidfd, F_SETFL, (flags & ~O_NONBLOCK)), 0);
- ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED, NULL), 0);
+ ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED), 0);
ASSERT_EQ(info.si_signo, SIGCHLD);
ASSERT_EQ(info.si_code, CLD_STOPPED);
ASSERT_EQ(info.si_pid, parent_tid);
ASSERT_EQ(sys_pidfd_send_signal(pidfd, SIGCONT, NULL, 0), 0);
- ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL), 0);
+ ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WEXITED), 0);
ASSERT_EQ(info.si_signo, SIGCHLD);
ASSERT_EQ(info.si_code, CLD_EXITED);
ASSERT_EQ(info.si_pid, parent_tid);
diff --git a/tools/testing/selftests/pidfd/pidfd_xattr_test.c b/tools/testing/selftests/pidfd/pidfd_xattr_test.c
new file mode 100644
index 000000000000..fd57511af7e4
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd_xattr_test.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <linux/types.h>
+#include <poll.h>
+#include <pthread.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syscall.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <linux/kcmp.h>
+#include <sys/stat.h>
+#include <sys/xattr.h>
+
+#include "pidfd.h"
+#include "kselftest_harness.h"
+
+FIXTURE(pidfs_xattr)
+{
+ pid_t child_pid;
+ int child_pidfd;
+};
+
+FIXTURE_SETUP(pidfs_xattr)
+{
+ self->child_pid = create_child(&self->child_pidfd, CLONE_NEWUSER | CLONE_NEWPID);
+ EXPECT_GE(self->child_pid, 0);
+
+ if (self->child_pid == 0)
+ _exit(EXIT_SUCCESS);
+}
+
+FIXTURE_TEARDOWN(pidfs_xattr)
+{
+ sys_waitid(P_PID, self->child_pid, NULL, WEXITED);
+}
+
+TEST_F(pidfs_xattr, set_get_list_xattr_multiple)
+{
+ int ret, i;
+ char xattr_name[32];
+ char xattr_value[32];
+ char buf[32];
+ const int num_xattrs = 10;
+ char list[PATH_MAX] = {};
+
+ for (i = 0; i < num_xattrs; i++) {
+ snprintf(xattr_name, sizeof(xattr_name), "trusted.testattr%d", i);
+ snprintf(xattr_value, sizeof(xattr_value), "testvalue%d", i);
+ ret = fsetxattr(self->child_pidfd, xattr_name, xattr_value, strlen(xattr_value), 0);
+ ASSERT_EQ(ret, 0);
+ }
+
+ for (i = 0; i < num_xattrs; i++) {
+ snprintf(xattr_name, sizeof(xattr_name), "trusted.testattr%d", i);
+ snprintf(xattr_value, sizeof(xattr_value), "testvalue%d", i);
+ memset(buf, 0, sizeof(buf));
+ ret = fgetxattr(self->child_pidfd, xattr_name, buf, sizeof(buf));
+ ASSERT_EQ(ret, strlen(xattr_value));
+ ASSERT_EQ(strcmp(buf, xattr_value), 0);
+ }
+
+ ret = flistxattr(self->child_pidfd, list, sizeof(list));
+ ASSERT_GT(ret, 0);
+ for (i = 0; i < num_xattrs; i++) {
+ snprintf(xattr_name, sizeof(xattr_name), "trusted.testattr%d", i);
+ bool found = false;
+ for (char *it = list; it < list + ret; it += strlen(it) + 1) {
+ if (strcmp(it, xattr_name))
+ continue;
+ found = true;
+ break;
+ }
+ ASSERT_TRUE(found);
+ }
+
+ for (i = 0; i < num_xattrs; i++) {
+ snprintf(xattr_name, sizeof(xattr_name), "trusted.testattr%d", i);
+ ret = fremovexattr(self->child_pidfd, xattr_name);
+ ASSERT_EQ(ret, 0);
+
+ ret = fgetxattr(self->child_pidfd, xattr_name, buf, sizeof(buf));
+ ASSERT_EQ(ret, -1);
+ ASSERT_EQ(errno, ENODATA);
+ }
+}
+
+TEST_F(pidfs_xattr, set_get_list_xattr_persistent)
+{
+ int ret;
+ char buf[32];
+ char list[PATH_MAX] = {};
+
+ ret = fsetxattr(self->child_pidfd, "trusted.persistent", "persistent value", strlen("persistent value"), 0);
+ ASSERT_EQ(ret, 0);
+
+ memset(buf, 0, sizeof(buf));
+ ret = fgetxattr(self->child_pidfd, "trusted.persistent", buf, sizeof(buf));
+ ASSERT_EQ(ret, strlen("persistent value"));
+ ASSERT_EQ(strcmp(buf, "persistent value"), 0);
+
+ ret = flistxattr(self->child_pidfd, list, sizeof(list));
+ ASSERT_GT(ret, 0);
+ ASSERT_EQ(strcmp(list, "trusted.persistent"), 0)
+
+ ASSERT_EQ(close(self->child_pidfd), 0);
+ self->child_pidfd = -EBADF;
+ sleep(2);
+
+ self->child_pidfd = sys_pidfd_open(self->child_pid, 0);
+ ASSERT_GE(self->child_pidfd, 0);
+
+ memset(buf, 0, sizeof(buf));
+ ret = fgetxattr(self->child_pidfd, "trusted.persistent", buf, sizeof(buf));
+ ASSERT_EQ(ret, strlen("persistent value"));
+ ASSERT_EQ(strcmp(buf, "persistent value"), 0);
+
+ ret = flistxattr(self->child_pidfd, list, sizeof(list));
+ ASSERT_GT(ret, 0);
+ ASSERT_EQ(strcmp(list, "trusted.persistent"), 0);
+}
+
+TEST_HARNESS_MAIN