Add vfork support

src/libos/src/process/do_exec.rs

@@ -3,14 +3,16 @@ use std::path::Path;
 
 use super::do_exit::exit_old_process_for_execve;
 use super::do_spawn::new_process_for_exec;
+use super::do_vfork::{check_vfork_for_exec, vfork_return_to_parent};
 use super::process::ProcessFilter;
 use super::term_status::TermStatus;
 use super::wait::Waiter;
 use super::{do_exit, do_exit_group};
 use super::{table, ProcessRef, ProcessStatus};
-use super::{task, ThreadRef};
+use super::{task, ThreadId, ThreadRef};
 use crate::interrupt::broadcast_interrupts;
 use crate::prelude::*;
+use crate::syscall::CpuContext;
 
 // FIXME: `occlum exec` command will return early if the application calls execve successfully.
 // Because the "execved"-ed application will run on a new thread and the current thread will exit.
@@ -21,30 +23,61 @@ pub fn do_exec(
     argv: &[CString],
     envp: &[CString],
     current_ref: &ThreadRef,
+    context: *mut CpuContext,
 ) -> Result<isize> {
     trace!(
         "exec current process pid = {:?}",
         current_ref.process().pid()
     );
 
-    // Construct new process structure but with same parent, pid, tid
+    let (is_vforked, tid, parent_process) =
-    let current = current!();
+        if let Some((tid, parent_process)) = check_vfork_for_exec(current_ref) {
-    let new_process_ref = super::do_spawn::new_process_for_exec(path, argv, envp, current_ref);
+            (true, tid, parent_process)
+        } else {
+            // Without vfork, current process directly calls execve.
+            // Construct new process structure but with same parent, pid, tid
+            (
+                false,
+                // Reuse self tid
+                ThreadId {
+                    tid: current_ref.process().pid() as u32,
+                },
+                // Reuse parent process as parent
+                Some(current_ref.process().parent().clone()),
+            )
+        };
+
+    let new_process_ref = super::do_spawn::new_process_for_exec(
+        path,
+        argv,
+        envp,
+        current_ref,
+        Some(tid),
+        parent_process,
+    );
 
     if let Ok(new_process_ref) = new_process_ref {
         let new_main_thread = new_process_ref
             .main_thread()
             .expect("the main thread is just created; it must exist");
 
+        if is_vforked {
+            // Don't exit current process if this is a vforked child process.
+            table::add_thread(new_process_ref.main_thread().unwrap());
+            table::add_process(new_process_ref);
+            task::enqueue_and_exec(new_main_thread);
+            return vfork_return_to_parent(context, current_ref);
+        }
+
         // Force exit all child threads of current process
         let term_status = TermStatus::Exited(0 as u8);
-        current.process().force_exit(term_status);
+        current_ref.process().force_exit(term_status);
 
         // Don't hesitate. Interrupt all threads right now (except the calling thread).
         broadcast_interrupts();
 
         // Wait for all threads (except calling thread) to exit
-        wait_for_other_threads_to_exit(current);
+        wait_for_other_threads_to_exit(current_ref);
 
         // Exit current thread and let new process to adopt current's child process
         exit_old_process_for_execve(term_status, new_process_ref.clone());
@@ -67,7 +100,7 @@ pub fn do_exec(
 }
 
 // Blocking wait until there is only one thread in the calling process
-fn wait_for_other_threads_to_exit(current_ref: ThreadRef) {
+fn wait_for_other_threads_to_exit(current_ref: &ThreadRef) {
     use super::do_futex::{self, FutexTimeout};
     use crate::time::{timespec_t, ClockID};
     use core::time::Duration;
@@ -78,7 +111,7 @@ fn wait_for_other_threads_to_exit(current_ref: ThreadRef) {
         timespec_t::from(Duration::from_millis(50)),
     );
     // Use calling process's pointer as futex value
-    let futex_val = Arc::as_ptr(&current_ref.process()) as *const i32;
+    let futex_val = Arc::as_ptr(current_ref.process()) as *const i32;
     loop {
         let thread_num = current_ref.process().threads().len();
         if thread_num == 1 {
@@ -87,7 +120,7 @@ fn wait_for_other_threads_to_exit(current_ref: ThreadRef) {
         // Blocking wait here. When a thread exit, it will notify us.
         unsafe {
             do_futex::futex_wait(
-                Arc::as_ptr(&current_ref.process()) as *const i32,
+                Arc::as_ptr(current_ref.process()) as *const i32,
                 *futex_val,
                 &Some(timeout),
             )

src/libos/src/process/do_exit.rs

@@ -2,16 +2,24 @@ use crate::signal::constants::*;
 use std::intrinsics::atomic_store;
 
 use super::do_futex::futex_wake;
+use super::do_vfork::{is_vforked_child_process, vfork_return_to_parent};
 use super::pgrp::clean_pgrp_when_exit;
 use super::process::{Process, ProcessFilter};
 use super::{table, ProcessRef, TermStatus, ThreadRef, ThreadStatus};
 use crate::prelude::*;
 use crate::signal::{KernelSignal, SigNum};
+use crate::syscall::CpuContext;
 
-pub fn do_exit_group(status: i32) {
+pub fn do_exit_group(status: i32, curr_user_ctxt: &mut CpuContext) -> Result<isize> {
-    let term_status = TermStatus::Exited(status as u8);
+    if is_vforked_child_process() {
-    current!().process().force_exit(term_status);
+        let current = current!();
-    exit_thread(term_status);
+        return vfork_return_to_parent(curr_user_ctxt as *mut _, &current);
+    } else {
+        let term_status = TermStatus::Exited(status as u8);
+        current!().process().force_exit(term_status);
+        exit_thread(term_status);
+        Ok(0)
+    }
 }
 
 pub fn do_exit(status: i32) {

src/libos/src/process/do_spawn/mod.rs

@@ -118,6 +118,7 @@ fn new_process(
         host_stdio_fds,
         current_ref,
         None,
+        None,
     )?;
     table::add_process(new_process_ref.clone());
     table::add_thread(new_process_ref.main_thread().unwrap());
@@ -131,6 +132,8 @@ pub fn new_process_for_exec(
     argv: &[CString],
     envp: &[CString],
     current_ref: &ThreadRef,
+    reuse_tid: Option<ThreadId>,
+    parent_process: Option<ProcessRef>,
 ) -> Result<ProcessRef> {
     let tid = ThreadId {
         tid: current_ref.process().pid() as u32,
@@ -143,7 +146,8 @@ pub fn new_process_for_exec(
         None,
         None,
         current_ref,
-        Some(tid),
+        reuse_tid,
+        parent_process,
     )?;
 
     Ok(new_process_ref)
@@ -158,6 +162,7 @@ fn new_process_common(
     host_stdio_fds: Option<&HostStdioFds>,
     current_ref: &ThreadRef,
     reuse_tid: Option<ThreadId>,
+    parent_process: Option<ProcessRef>,
 ) -> Result<ProcessRef> {
     let mut argv = argv.clone().to_vec();
     let (is_script, elf_inode, mut elf_buf, elf_header) =
@@ -279,15 +284,20 @@ fn new_process_common(
         let elf_name = elf_path.rsplit('/').collect::<Vec<&str>>()[0];
         let thread_name = ThreadName::new(elf_name);
 
-        let mut parent;
         let mut process_builder = ProcessBuilder::new();
-        if reuse_tid.is_some() {
+
-            process_builder = process_builder.tid(reuse_tid.unwrap());
+        // Use specified tid if any
-            parent = current!().process().parent();
+        if let Some(reuse_tid) = reuse_tid {
-        } else {
+            process_builder = process_builder.tid(reuse_tid);
-            parent = process_ref;
         }
 
+        // Use specified parent process if any
+        let parent = if let Some(parent) = parent_process {
+            parent
+        } else {
+            process_ref
+        };
+
         let new_process = process_builder
             .vm(vm_ref)
             .exec_path(&elf_path)

src/libos/src/process/do_vfork.rs

@@ -0,0 +1,133 @@
+use super::{ProcessRef, ThreadId, ThreadRef};
+use crate::fs::FileTable;
+use crate::prelude::*;
+use crate::syscall::CpuContext;
+use std::collections::HashMap;
+use std::mem;
+
+// From Man page: The calling thread is suspended until the child terminates (either normally, by calling
+// _exit(2), or abnormally, after delivery of a fatal signal), or it makes a call to execve(2).
+// Until that point, the child shares all memory with its parent, including the stack.
+//
+// Thus in this implementation, the main idea is to let child use parent's task until exit or execve.
+//
+// Limitation:
+// The child process will not have a complete process structure before execve. Thus during the time from vfork
+// to new child process execve or exit, the child process just reuse the parent process's everything, including
+// task, pid and etc. And also the log of child process will not start from the point that vfork returns but the
+// point that execve returns.
+
+lazy_static! {
+    // Store all the parents's file tables who call vfork. It will be recovered when the child exits or has its own task.
+    // K: parent pid, V: parent file table
+    static ref VFORK_PARENT_FILE_TABLES: SgxMutex<HashMap<pid_t, FileTable>> = SgxMutex::new(HashMap::new());
+}
+
+thread_local! {
+    // Store the current process' vforked child and current thread's cpu context. A parent only has one vforked child at a time.
+    static VFORK_CONTEXT: RefCell<Option<(pid_t, CpuContext)>> = Default::default();
+}
+
+pub fn do_vfork(mut context: *mut CpuContext) -> Result<isize> {
+    let current = current!();
+    trace!("vfork parent process pid = {:?}", current.process().pid());
+
+    // Generate a new pid for child process
+    let child_pid = {
+        let new_tid = ThreadId::new();
+        new_tid.as_u32() as pid_t
+    };
+
+    // Save parent's context in TLS
+    VFORK_CONTEXT.with(|cell| {
+        let mut ctx = cell.borrow_mut();
+        let new_context = (child_pid, unsafe { (*context).clone() });
+        *ctx = Some(new_context);
+    });
+
+    // Save parent's file table
+    let parent_pid = current.process().pid();
+    let mut vfork_file_tables = VFORK_PARENT_FILE_TABLES.lock().unwrap();
+    let parent_file_table = {
+        let mut current_file_table = current.files().lock().unwrap();
+        let new_file_table = current_file_table.clone();
+        // FileTable contains non-cloned struct, so here we do a memory replacement to use new
+        // file table in child and store the original file table in TLS.
+        mem::replace(&mut *current_file_table, new_file_table)
+    };
+    if let Some(_) = vfork_file_tables.insert(parent_pid, parent_file_table) {
+        return_errno!(EINVAL, "current process's vfork has not returned yet");
+    }
+
+    // This is the first time return and will return as child.
+    // The second time return will return as parent in vfork_return_to_parent.
+    info!("vfork child pid = {:?}", child_pid);
+    return Ok(0 as isize);
+}
+
+// Check if the calling process is a vforked child process that reuse parent's task and pid.
+pub fn is_vforked_child_process() -> bool {
+    VFORK_CONTEXT.with(|cell| {
+        let ctx = cell.borrow();
+        return ctx.is_some();
+    })
+}
+
+// Return to parent process to continue executing
+pub fn vfork_return_to_parent(
+    mut context: *mut CpuContext,
+    current_ref: &ThreadRef,
+) -> Result<isize> {
+    return restore_parent_process(context, current_ref);
+}
+
+fn restore_parent_process(mut context: *mut CpuContext, current_ref: &ThreadRef) -> Result<isize> {
+    let current_thread = current!();
+    let current_pid = current_ref.process().pid();
+
+    // Restore parent file table
+    let parent_file_table = {
+        let mut parent_file_tables = VFORK_PARENT_FILE_TABLES.lock().unwrap();
+        if let Some(table) = parent_file_tables.remove(&current_pid) {
+            table
+        } else {
+            return_errno!(EFAULT, "couldn't restore parent file table");
+        }
+    };
+    let mut current_file_table = current_ref.files().lock().unwrap();
+    *current_file_table = parent_file_table;
+
+    // Get child pid and restore CpuContext
+    let mut child_pid = 0;
+    VFORK_CONTEXT.with(|cell| {
+        let mut ctx = cell.borrow_mut();
+        child_pid = ctx.unwrap().0;
+        unsafe { *context = ctx.unwrap().1 };
+        *ctx = None;
+    });
+
+    // Set return value to child_pid
+    // This will be the second time return
+    Ok(child_pid as isize)
+}
+
+pub fn check_vfork_for_exec(current_ref: &ThreadRef) -> Option<(ThreadId, Option<ProcessRef>)> {
+    let current_pid = current_ref.process().pid();
+    if is_vforked_child_process() {
+        let mut child_pid = 0;
+        VFORK_CONTEXT.with(|cell| {
+            let ctx = cell.borrow().unwrap();
+            child_pid = ctx.0;
+        });
+        return Some((
+            // Reuse tid which was generated when do_vfork
+            ThreadId {
+                tid: child_pid as u32,
+            },
+            // By default, use current process as parent
+            None,
+        ));
+    } else {
+        None
+    }
+}

src/libos/src/process/mod.rs

@@ -25,6 +25,7 @@ pub use self::do_exit::handle_force_exit;
 pub use self::do_futex::{futex_wait, futex_wake};
 pub use self::do_robust_list::RobustListHead;
 pub use self::do_spawn::do_spawn_without_exec;
+pub use self::do_vfork::do_vfork;
 pub use self::do_wait4::idle_reap_zombie_children;
 pub use self::process::{Process, ProcessFilter, ProcessStatus, IDLE};
 pub use self::spawn_attribute::posix_spawnattr_t;
@@ -43,6 +44,7 @@ mod do_getpid;
 mod do_robust_list;
 mod do_set_tid_address;
 mod do_spawn;
+mod do_vfork;
 mod do_wait4;
 mod pgrp;
 mod prctl;

src/libos/src/process/syscalls.rs

@@ -10,6 +10,7 @@ use super::prctl::PrctlCmd;
 use super::process::ProcessFilter;
 use super::spawn_attribute::{clone_spawn_atrributes_safely, posix_spawnattr_t, SpawnAttr};
 use crate::prelude::*;
+use crate::syscall::CpuContext;
 use crate::time::{timespec_t, ClockID};
 use crate::util::mem_util::from_user::*;
 use std::ptr::NonNull;
@@ -341,10 +342,10 @@ pub fn do_exit(status: i32) -> Result<isize> {
     Ok(0)
 }
 
-pub fn do_exit_group(status: i32) -> Result<isize> {
+pub fn do_exit_group(status: i32, user_context: *mut CpuContext) -> Result<isize> {
     debug!("exit_group: {}", status);
-    super::do_exit::do_exit_group(status);
+    let user_context = unsafe { &mut *user_context };
-    Ok(0)
+    return super::do_exit::do_exit_group(status, user_context);
 }
 
 pub fn do_wait4(pid: i32, exit_status_ptr: *mut i32, options: u32) -> Result<isize> {
@@ -469,7 +470,12 @@ pub fn do_getgroups(size: isize, buf_ptr: *mut u32) -> Result<isize> {
     }
 }
 
-pub fn do_execve(path: *const i8, argv: *const *const i8, envp: *const *const i8) -> Result<isize> {
+pub fn do_execve(
+    path: *const i8,
+    argv: *const *const i8,
+    envp: *const *const i8,
+    context: *mut CpuContext,
+) -> Result<isize> {
     let path = clone_cstring_safely(path)?.to_string_lossy().into_owned();
     let argv = clone_cstrings_safely(argv)?;
     let envp = clone_cstrings_safely(envp)?;
@@ -479,7 +485,7 @@ pub fn do_execve(path: *const i8, argv: *const *const i8, envp: *const *const i8
         path, argv, envp
     );
 
-    do_exec(&path, &argv, &envp, &current)
+    do_exec(&path, &argv, &envp, &current, context)
 }
 
 pub fn do_set_robust_list(list_head_ptr: *mut RobustListHead, len: usize) -> Result<isize> {

src/libos/src/syscall/mod.rs

@@ -45,7 +45,7 @@ use crate::process::{
     do_arch_prctl, do_clone, do_execve, do_exit, do_exit_group, do_futex, do_get_robust_list,
     do_getegid, do_geteuid, do_getgid, do_getgroups, do_getpgid, do_getpgrp, do_getpid, do_getppid,
     do_gettid, do_getuid, do_prctl, do_set_robust_list, do_set_tid_address, do_setpgid,
-    do_spawn_for_glibc, do_spawn_for_musl, do_wait4, pid_t, posix_spawnattr_t, FdOp,
+    do_spawn_for_glibc, do_spawn_for_musl, do_vfork, do_wait4, pid_t, posix_spawnattr_t, FdOp,
     RobustListHead, SpawnFileActions, ThreadStatus,
 };
 use crate::sched::{do_getcpu, do_sched_getaffinity, do_sched_setaffinity, do_sched_yield};
@@ -146,8 +146,8 @@ macro_rules! process_syscall_table_with_callback {
             (Getsockopt = 55) => do_getsockopt(fd: c_int, level: c_int, optname: c_int, optval: *mut c_void, optlen: *mut libc::socklen_t),
             (Clone = 56) => do_clone(flags: u32, stack_addr: usize, ptid: *mut pid_t, ctid: *mut pid_t, new_tls: usize),
             (Fork = 57) => handle_unsupported(),
-            (Vfork = 58) => handle_unsupported(),
+            (Vfork = 58) => do_vfork(context: *mut CpuContext),
-            (Execve = 59) => do_execve(path: *const i8, argv: *const *const i8, envp: *const *const i8),
+            (Execve = 59) => do_execve(path: *const i8, argv: *const *const i8, envp: *const *const i8, context: *mut CpuContext),
             (Exit = 60) => do_exit(exit_status: i32),
             (Wait4 = 61) => do_wait4(pid: i32, _exit_status: *mut i32, options: u32),
             (Kill = 62) => do_kill(pid: i32, sig: c_int),
@@ -319,7 +319,7 @@ macro_rules! process_syscall_table_with_callback {
             (ClockGettime = 228) => do_clock_gettime(clockid: clockid_t, ts_u: *mut timespec_t),
             (ClockGetres = 229) => do_clock_getres(clockid: clockid_t, res_u: *mut timespec_t),
             (ClockNanosleep = 230) => handle_unsupported(),
-            (ExitGroup = 231) => do_exit_group(exit_status: i32),
+            (ExitGroup = 231) => do_exit_group(exit_status: i32, user_context: *mut CpuContext),
             (EpollWait = 232) => do_epoll_wait(epfd: c_int, events: *mut libc::epoll_event, maxevents: c_int, timeout: c_int),
             (EpollCtl = 233) => do_epoll_ctl(epfd: c_int, op: c_int, fd: c_int, event: *const libc::epoll_event),
             (Tgkill = 234) => do_tgkill(pid: i32, tid: pid_t, sig: c_int),
@@ -631,6 +631,16 @@ fn do_syscall(user_context: &mut CpuContext) {
         // need to modify it
         if syscall_num == SyscallNum::RtSigreturn {
             syscall.args[0] = user_context as *mut _ as isize;
+        } else if syscall_num == SyscallNum::Vfork {
+            syscall.args[0] = user_context as *mut _ as isize;
+        } else if syscall_num == SyscallNum::Execve {
+            // syscall.args[0] == path
+            // syscall.args[1] == argv
+            // syscall.args[2] == envp
+            syscall.args[3] = user_context as *mut _ as isize;
+        } else if syscall_num == SyscallNum::ExitGroup {
+            // syscall.args[0] == status
+            syscall.args[1] = user_context as *mut _ as isize;
         } else if syscall_num == SyscallNum::HandleException {
             // syscall.args[0] == info
             // syscall.args[1] == fpregs

test/Makefile

@@ -19,7 +19,7 @@ TESTS ?= env empty hello_world malloc mmap file fs_perms getpid spawn sched pipe
 	truncate readdir mkdir open stat link symlink chmod chown tls pthread system_info resolv_conf rlimit \
 	server server_epoll unix_socket cout hostfs cpuid rdtsc device sleep exit_group \
 	ioctl fcntl eventfd emulate_syscall access signal sysinfo prctl rename procfs wait \
-	spawn_attribute exec statfs umask pgrp
+	spawn_attribute exec statfs umask pgrp vfork
 # Benchmarks: need to be compiled and run by bench-% target
 BENCHES := spawn_and_exit_latency pipe_throughput unix_socket_throughput
 

test/naughty_child/main.c

@@ -190,6 +190,39 @@ int test_execve_child_thread() {
     return -1;
 }
 
+// /bin/naughty_child -t vfork reader_fd writer_fd
+// pipe_reader should remain open becuase it is inherited.
+// pipe_writer should be closed already before execve naughty_child.
+int test_vfork_child() {
+    int pipe_reader_fd = atoi(g_argv[3]);
+    int pipe_writer_fd = atoi(g_argv[4]);
+    char buf[30] = {0};
+    struct stat stat_buf;
+
+    int ret = read(pipe_reader_fd, buf, sizeof(buf));
+    if (ret < 0) {
+        THROW_ERROR("[child] read from pipe error");
+    }
+
+    // Check pipe reader
+    if (fstat(pipe_reader_fd, &stat_buf) < 0 ) {
+        THROW_ERROR("[child] fstat pipe files error");
+    }
+
+    if (!S_ISFIFO(stat_buf.st_mode)) {
+        THROW_ERROR("failed to check the pipe reader st_mode");
+    }
+
+    // Check pipe writer which should be closed already
+    ret = fstat(pipe_writer_fd, &stat_buf);
+    if (ret >= 0 || errno != EBADF) {
+        THROW_ERROR("failed to check the pipe writer which should be closed");
+    }
+
+    printf("[child] received mesg: %s", buf);
+    return 0;
+}
+
 // ============================================================================
 // Test suite
 // ============================================================================
@@ -205,6 +238,8 @@ int start_test(const char *test_name) {
         return test_ioctl_fioclex();
     } else if (strcmp(test_name, "execve_thread") == 0) {
         return test_execve_child_thread();
+    } else if (strcmp(test_name, "vfork") == 0) {
+        return test_vfork_child();
     } else {
         fprintf(stderr, "[child] test case not found\n");
         return -1;
@@ -213,7 +248,8 @@ int start_test(const char *test_name) {
 
 void print_usage() {
     fprintf(stderr, "Usage:\n naughty_child [-t testcase1] [-t testcase2] ...\n\n");
-    fprintf(stderr, " Now support testcase: <sigmask, sigdef, fioclex, execve_thread>\n");
+    fprintf(stderr,
+            " Now support testcase: <sigmask, sigdef, fioclex, execve_thread, vfork>\n");
 }
 
 int main(int argc, char *argv[]) {

test/spawn/Makefile

@@ -1,5 +1,5 @@
 include ../test_common.mk
 
-EXTRA_C_FLAGS :=
+EXTRA_C_FLAGS := -g
 EXTRA_LINK_FLAGS :=
 BIN_ARGS :=

test/vfork/Makefile

@@ -0,0 +1,5 @@
+include ../test_common.mk
+
+EXTRA_C_FLAGS := -g
+EXTRA_LINK_FLAGS :=
+BIN_ARGS :=

test/vfork/main.c

@@ -0,0 +1,100 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include "test.h"
+
+// Note: This test intends to test the case that child process directly calls _exit()
+// after vfork. "exit", "_exit" and returning from main function are different.
+// And here the exit function must be "_exit" to prevent undefined bevaviour.
+int test_vfork_exit() {
+    pid_t child_pid = vfork();
+    if (child_pid == 0) {
+        _exit(0);
+    } else {
+        printf ("Comming back to parent process from child with pid = %d\n", child_pid);
+    }
+    return 0;
+}
+
+int test_multiple_vfork_execve() {
+    char **child_argv = calloc(1, sizeof(char *) * 2); // "hello_world", NULL
+    child_argv[0] = strdup("naughty_child");
+    for (int i = 0; i < 3; i++ ) {
+        pid_t child_pid = vfork();
+        if (child_pid == 0) {
+            int ret = execve("/bin/naughty_child", child_argv, NULL);
+            if (ret != 0) {
+                printf("child process execve error");
+            }
+            _exit(1);
+        } else {
+            printf ("Comming back to parent process from child with pid = %d\n", child_pid);
+            int ret = waitpid(child_pid, 0, 0);
+            if (ret != child_pid) {
+                THROW_ERROR("wait child error, child pid = %d\n", child_pid);
+            }
+        }
+    }
+    return 0;
+}
+
+// Create a pipe between parent and child and check file status.
+int test_vfork_isolate_file_table() {
+    int pipe_fds[2];
+    if (pipe(pipe_fds) < 0) {
+        THROW_ERROR("failed to create a pipe");
+    }
+
+    pid_t child_pid = vfork();
+    if (child_pid == 0) {
+        close(pipe_fds[1]); // close write end
+        char **child_argv = calloc(1,
+                                   sizeof(char *) * (5 + 1)); // naughty_child -t vfork reader_fd writer_fd
+        child_argv[0] = "naughty_child";
+        child_argv[1] = "-t";
+        child_argv[2] = "vfork";
+        if (asprintf(&child_argv[3], "%d", pipe_fds[0]) < 0 ||
+                asprintf(&child_argv[4], "%d", pipe_fds[1]) < 0) {
+            THROW_ERROR("failed to asprintf");
+        }
+
+        int ret = execve("/bin/naughty_child", child_argv, NULL);
+        if (ret != 0) {
+            printf("child process execve error\n");
+        }
+        _exit(1);
+    } else {
+        printf ("Comming back to parent process from child with pid = %d\n", child_pid);
+        if (close(pipe_fds[0]) < 0) { // close read end
+            printf("close pipe reader error\n");
+            goto parent_exit;
+        }
+        char *greetings = "Hello from parent\n";
+        if (write(pipe_fds[1], greetings, strlen(greetings) + 1) < 0) {
+            printf("parent write pipe error\n");
+            goto parent_exit;
+        }
+        int ret = waitpid(child_pid, 0, 0);
+        if (ret != child_pid) {
+            THROW_ERROR("wait child error, child pid = %d\n", child_pid);
+        }
+    }
+
+    return 0;
+
+parent_exit:
+    kill(child_pid, SIGKILL);
+    exit(1);
+}
+
+static test_case_t test_cases[] = {
+    TEST_CASE(test_vfork_exit),
+    TEST_CASE(test_multiple_vfork_execve),
+    TEST_CASE(test_vfork_isolate_file_table),
+};
+
+int main() {
+    return test_suite_run(test_cases, ARRAY_SIZE(test_cases));
+}