Patch feat robust futex (#682)

* feat: 实现robust lock机制

* 前面更改vscode,修改回来

* 修改dadk的路径

* 提交.gitnore和.cargo,删除LICENSE,修改README

* 修改一个warn

* 删除.rustc_info.json

* 删除target文件夹

* 恢复DragonOS的LICENSE,删除Cargo.lock

* 将校验用户空间地址的代码写入函数内;将部分match分支用ok_or代替

* 修改wakeup函数获取running queue时unwrap一个None值发生panic

* 测试程序使用syscalls库进行系统调用
This commit is contained in:
hmt 2024-04-06 22:26:34 +08:00 committed by GitHub
parent 23ef2b33d1
commit 06560afa2a
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
11 changed files with 825 additions and 15 deletions

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@ -3,7 +3,12 @@ use alloc::{
sync::{Arc, Weak},
};
use core::hash::{Hash, Hasher};
use core::{intrinsics::likely, sync::atomic::AtomicU64};
use core::{
intrinsics::{likely, unlikely},
mem,
sync::atomic::AtomicU64,
};
use hashbrown::HashMap;
use system_error::SystemError;
@ -12,9 +17,9 @@ use crate::{
exception::InterruptArch,
libs::spinlock::{SpinLock, SpinLockGuard},
mm::{ucontext::AddressSpace, MemoryManagementArch, VirtAddr},
process::{ProcessControlBlock, ProcessManager},
process::{Pid, ProcessControlBlock, ProcessManager},
sched::{schedule, SchedMode},
syscall::user_access::UserBufferReader,
syscall::user_access::{UserBufferReader, UserBufferWriter},
time::{
timer::{next_n_us_timer_jiffies, Timer, WakeUpHelper},
TimeSpec,
@ -635,3 +640,251 @@ impl Futex {
Ok(*oldval)
}
}
//用于指示在处理robust list是最多处理多少个条目
const ROBUST_LIST_LIMIT: isize = 2048;
#[derive(Debug, Copy, Clone)]
pub struct RobustList {
next: VirtAddr,
}
#[derive(Debug, Copy, Clone)]
pub struct RobustListHead {
list: RobustList,
futex_offset: isize,
list_op_pending: VirtAddr,
}
impl RobustListHead {
/// # 获得futex的用户空间地址
pub fn futex_uaddr(&self, entry: VirtAddr) -> VirtAddr {
return VirtAddr::new(entry.data() + self.futex_offset as usize);
}
/// #获得list_op_peding的用户空间地址
pub fn pending_uaddr(&self) -> Option<VirtAddr> {
if self.list_op_pending.is_null() {
return None;
} else {
return Some(self.futex_uaddr(self.list_op_pending));
}
}
/// # 在内核注册robust list
/// ## 参数
/// - head_uaddrrobust list head用户空间地址
/// - lenrobust list head的长度
pub fn set_robust_list(head_uaddr: VirtAddr, len: usize) -> Result<usize, SystemError> {
let robust_list_head_len = mem::size_of::<&RobustListHead>();
if unlikely(len != robust_list_head_len) {
return Err(SystemError::EINVAL);
}
let user_buffer_reader = UserBufferReader::new(
head_uaddr.as_ptr::<RobustListHead>(),
mem::size_of::<RobustListHead>(),
true,
)?;
let robust_list_head = *user_buffer_reader.read_one_from_user::<RobustListHead>(0)?;
// 向内核注册robust list
ProcessManager::current_pcb().set_robust_list(Some(robust_list_head));
return Ok(0);
}
/// # 获取robust list head到用户空间
/// ## 参数
/// - pid当前进程/线程的pid
/// -
pub fn get_robust_list(
pid: usize,
head_uaddr: VirtAddr,
len_ptr_uaddr: VirtAddr,
) -> Result<usize, SystemError> {
// 获取当前进程的process control block
let pcb: Arc<ProcessControlBlock> = if pid == 0 {
ProcessManager::current_pcb()
} else {
ProcessManager::find(Pid::new(pid)).ok_or(SystemError::ESRCH)?
};
// TODO: 检查当前进程是否能ptrace另一个进程
let ptrace = true;
if !ptrace {
return Err(SystemError::EPERM);
}
//获取当前线程的robust list head 和 长度
let robust_list_head = (*pcb.get_robust_list()).ok_or(SystemError::EINVAL)?;
// 将len拷贝到用户空间len_ptr
let mut user_writer = UserBufferWriter::new(
len_ptr_uaddr.as_ptr::<usize>(),
core::mem::size_of::<usize>(),
true,
)?;
user_writer.copy_one_to_user(&mem::size_of::<RobustListHead>(), 0)?;
// 将head拷贝到用户空间head
let mut user_writer = UserBufferWriter::new(
head_uaddr.as_ptr::<RobustListHead>(),
mem::size_of::<RobustListHead>(),
true,
)?;
user_writer.copy_one_to_user(&robust_list_head, 0)?;
return Ok(0);
}
/// # 进程/线程退出时清理工作
/// ## 参数
/// - current当前进程/线程的pcb
/// - pid当前进程/线程的pid
pub fn exit_robust_list(pcb: Arc<ProcessControlBlock>) {
//指向当前进程的robust list头部的指针
let head = match *pcb.get_robust_list() {
Some(rl) => rl,
None => {
return;
}
};
// 遍历当前进程/线程的robust list
for futex_uaddr in head.futexes() {
let ret = Self::handle_futex_death(futex_uaddr, pcb.pid().into() as u32);
if ret.is_err() {
return;
}
}
pcb.set_robust_list(None);
}
/// # 返回robust list的迭代器将robust list list_op_pending 放到最后(如果存在)
fn futexes(&self) -> FutexIterator<'_> {
return FutexIterator::new(self);
}
/// # 处理进程即将死亡时进程已经持有的futex唤醒其他等待该futex的线程
/// ## 参数
/// - futex_uaddrfutex的用户空间地址
/// - pid: 当前进程/线程的pid
fn handle_futex_death(futex_uaddr: VirtAddr, pid: u32) -> Result<usize, SystemError> {
let futex_val = {
if futex_uaddr.is_null() {
return Err(SystemError::EINVAL);
}
let user_buffer_reader = UserBufferReader::new(
futex_uaddr.as_ptr::<u32>(),
core::mem::size_of::<u32>(),
true,
)?;
*user_buffer_reader.read_one_from_user::<u32>(0)?
};
let mut uval = futex_val;
loop {
// 该futex可能被其他进程占有
let owner = uval & FUTEX_TID_MASK;
if owner != pid {
break;
}
// 判断是否有FUTEX_WAITERS和标记FUTEX_OWNER_DIED
let mval = (uval & FUTEX_WAITERS) | FUTEX_OWNER_DIED;
// 读取用户空间目前的futex字段判断在此之前futex是否有被修改
let user_buffer_reader = UserBufferReader::new(
futex_uaddr.as_ptr::<u32>(),
core::mem::size_of::<u32>(),
true,
)?;
let nval = *user_buffer_reader.read_one_from_user::<u32>(0)?;
if nval != mval {
uval = nval;
let mut user_buffer_writer = UserBufferWriter::new(
futex_uaddr.as_ptr::<u32>(),
core::mem::size_of::<u32>(),
true,
)?;
user_buffer_writer.copy_one_to_user(&mval, 0)?;
continue;
}
// 有等待者,进行唤醒操作
if nval & FUTEX_WAITERS != 0 {
let mut flags = FutexFlag::FLAGS_MATCH_NONE;
flags.insert(FutexFlag::FLAGS_SHARED);
Futex::futex_wake(futex_uaddr, flags, 1, FUTEX_BITSET_MATCH_ANY)?;
}
break;
}
return Ok(0);
}
}
pub struct FutexIterator<'a> {
robust_list_head: &'a RobustListHead,
entry: VirtAddr,
count: isize,
}
impl<'a> FutexIterator<'a> {
pub fn new(robust_list_head: &'a RobustListHead) -> Self {
return Self {
robust_list_head,
entry: robust_list_head.list.next,
count: 0,
};
}
fn is_end(&mut self) -> bool {
return self.count < 0;
}
}
impl<'a> Iterator for FutexIterator<'a> {
type Item = VirtAddr;
fn next(&mut self) -> Option<Self::Item> {
if self.is_end() {
return None;
}
while self.entry.data() != &self.robust_list_head.list as *const RobustList as usize {
if self.count == ROBUST_LIST_LIMIT {
break;
}
if self.entry.is_null() {
return None;
}
//获取futex val地址
let futex_uaddr = if self.entry.data() != self.robust_list_head.list_op_pending.data() {
Some(self.robust_list_head.futex_uaddr(self.entry))
} else {
None
};
let user_buffer_reader = UserBufferReader::new(
self.entry.as_ptr::<RobustList>(),
mem::size_of::<RobustList>(),
true,
)
.ok()?;
let next_entry = user_buffer_reader
.read_one_from_user::<RobustList>(0)
.ok()?;
self.entry = next_entry.next;
self.count += 1;
if futex_uaddr.is_some() {
return futex_uaddr;
}
}
self.count -= 1;
self.robust_list_head.pending_uaddr()
}
}

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@ -1,8 +1,15 @@
use system_error::SystemError;
use crate::{mm::VirtAddr, syscall::Syscall, time::TimeSpec};
use crate::{
mm::{verify_area, VirtAddr},
syscall::Syscall,
time::TimeSpec,
};
use super::{constant::*, futex::Futex};
use super::{
constant::*,
futex::{Futex, RobustListHead},
};
impl Syscall {
pub fn do_futex(
@ -14,6 +21,9 @@ impl Syscall {
val2: u32,
val3: u32,
) -> Result<usize, SystemError> {
verify_area(uaddr, core::mem::size_of::<u32>())?;
verify_area(uaddr2, core::mem::size_of::<u32>())?;
let cmd = FutexArg::from_bits(operation.bits() & FutexFlag::FUTEX_CMD_MASK.bits())
.ok_or(SystemError::ENOSYS)?;
@ -101,4 +111,25 @@ impl Syscall {
}
}
}
pub fn set_robust_list(head_uaddr: VirtAddr, len: usize) -> Result<usize, SystemError> {
//判断用户空间地址的合法性
verify_area(head_uaddr, core::mem::size_of::<u32>())?;
let ret = RobustListHead::set_robust_list(head_uaddr, len);
return ret;
}
pub fn get_robust_list(
pid: usize,
head_uaddr: VirtAddr,
len_ptr_uaddr: VirtAddr,
) -> Result<usize, SystemError> {
//判断用户空间地址的合法性
verify_area(head_uaddr, core::mem::size_of::<u32>())?;
verify_area(len_ptr_uaddr, core::mem::size_of::<u32>())?;
let ret = RobustListHead::get_robust_list(pid, head_uaddr, len_ptr_uaddr);
return ret;
}
}

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@ -16,6 +16,7 @@ use system_error::SystemError;
use crate::{
arch::{
cpu::current_cpu_id,
ipc::signal::{AtomicSignal, SigSet, Signal},
process::ArchPCBInfo,
CurrentIrqArch,
@ -33,7 +34,7 @@ use crate::{
casting::DowncastArc,
futex::{
constant::{FutexFlag, FUTEX_BITSET_MATCH_ANY},
futex::Futex,
futex::{Futex, RobustListHead},
},
lock_free_flags::LockFreeFlags,
rwlock::{RwLock, RwLockReadGuard, RwLockWriteGuard},
@ -230,7 +231,8 @@ impl ProcessManager {
// avoid deadlock
drop(writer);
let rq = cpu_rq(pcb.sched_info().on_cpu().unwrap().data() as usize);
let rq =
cpu_rq(pcb.sched_info().on_cpu().unwrap_or(current_cpu_id()).data() as usize);
let (rq, _guard) = rq.self_lock();
rq.update_rq_clock();
@ -405,6 +407,8 @@ impl ProcessManager {
unsafe { clear_user(addr, core::mem::size_of::<i32>()).expect("clear tid failed") };
}
RobustListHead::exit_robust_list(pcb.clone());
// 如果是vfork出来的进程则需要处理completion
if thread.vfork_done.is_some() {
thread.vfork_done.as_ref().unwrap().complete_all();
@ -629,6 +633,9 @@ pub struct ProcessControlBlock {
/// 线程信息
thread: RwLock<ThreadInfo>,
/// 进程的robust lock列表
robust_list: RwLock<Option<RobustListHead>>,
}
impl ProcessControlBlock {
@ -694,6 +701,7 @@ impl ProcessControlBlock {
children: RwLock::new(Vec::new()),
wait_queue: WaitQueue::default(),
thread: RwLock::new(ThreadInfo::new()),
robust_list: RwLock::new(None),
};
// 初始化系统调用栈
@ -940,6 +948,16 @@ impl ProcessControlBlock {
pub fn sig_struct_irqsave(&self) -> SpinLockGuard<SignalStruct> {
self.sig_struct.lock_irqsave()
}
#[inline(always)]
pub fn get_robust_list(&self) -> RwLockReadGuard<Option<RobustListHead>> {
return self.robust_list.read_irqsave();
}
#[inline(always)]
pub fn set_robust_list(&self, new_robust_list: Option<RobustListHead>) {
*self.robust_list.write_irqsave() = new_robust_list;
}
}
impl Drop for ProcessControlBlock {

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@ -690,9 +690,6 @@ impl Syscall {
let uaddr2 = VirtAddr::new(args[4]);
let val3 = args[5] as u32;
verify_area(uaddr, core::mem::size_of::<u32>())?;
verify_area(uaddr2, core::mem::size_of::<u32>())?;
let mut timespec = None;
if utime != 0 && operation.contains(FutexFlag::FLAGS_HAS_TIMEOUT) {
let reader = UserBufferReader::new(
@ -707,6 +704,26 @@ impl Syscall {
Self::do_futex(uaddr, operation, val, timespec, uaddr2, utime as u32, val3)
}
SYS_SET_ROBUST_LIST => {
let head = args[0];
let head_uaddr = VirtAddr::new(head);
let len = args[1];
let ret = Self::set_robust_list(head_uaddr, len);
return ret;
}
SYS_GET_ROBUST_LIST => {
let pid = args[0];
let head = args[1];
let head_uaddr = VirtAddr::new(head);
let len_ptr = args[2];
let len_ptr_uaddr = VirtAddr::new(len_ptr);
let ret = Self::get_robust_list(pid, head_uaddr, len_ptr_uaddr);
return ret;
}
SYS_READV => Self::readv(args[0] as i32, args[1], args[2]),
SYS_WRITEV => Self::writev(args[0] as i32, args[1], args[2]),
@ -952,11 +969,6 @@ impl Syscall {
Ok(0)
}
SYS_SET_ROBUST_LIST => {
kwarn!("SYS_SET_ROBUST_LIST has not yet been implemented");
Ok(0)
}
SYS_RSEQ => {
kwarn!("SYS_RSEQ has not yet been implemented");
Ok(0)

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@ -0,0 +1,2 @@
[build]
target = "x86_64-unknown-linux-musl"

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@ -0,0 +1,3 @@
/target
Cargo.lock
/install/

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@ -0,0 +1,12 @@
[package]
name = "test-for-robustfutex"
version = "0.1.0"
edition = "2021"
description = "some tests for robust futex"
authors = [ "hmt <1037827920@qq.com>" ]
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]
syscalls = '0.6.18'
libc = '0.2.153'

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@ -0,0 +1,56 @@
TOOLCHAIN="+nightly-2023-08-15-x86_64-unknown-linux-gnu"
RUSTFLAGS+=""
ifdef DADK_CURRENT_BUILD_DIR
# 如果是在dadk中编译那么安装到dadk的安装目录中
INSTALL_DIR = $(DADK_CURRENT_BUILD_DIR)
else
# 如果是在本地编译那么安装到当前目录下的install目录中
INSTALL_DIR = ./install
endif
ifeq ($(ARCH), x86_64)
export RUST_TARGET=x86_64-unknown-linux-musl
else ifeq ($(ARCH), riscv64)
export RUST_TARGET=riscv64gc-unknown-linux-gnu
else
# 默认为x86_86用于本地编译
export RUST_TARGET=x86_64-unknown-linux-musl
endif
run:
RUSTFLAGS=$(RUSTFLAGS) cargo $(TOOLCHAIN) run --target $(RUST_TARGET)
build:
RUSTFLAGS=$(RUSTFLAGS) cargo $(TOOLCHAIN) build --target $(RUST_TARGET)
clean:
RUSTFLAGS=$(RUSTFLAGS) cargo $(TOOLCHAIN) clean --target $(RUST_TARGET)
test:
RUSTFLAGS=$(RUSTFLAGS) cargo $(TOOLCHAIN) test --target $(RUST_TARGET)
doc:
RUSTFLAGS=$(RUSTFLAGS) cargo $(TOOLCHAIN) doc --target $(RUST_TARGET)
fmt:
RUSTFLAGS=$(RUSTFLAGS) cargo $(TOOLCHAIN) fmt
fmt-check:
RUSTFLAGS=$(RUSTFLAGS) cargo $(TOOLCHAIN) fmt --check
run-release:
RUSTFLAGS=$(RUSTFLAGS) cargo $(TOOLCHAIN) run --target $(RUST_TARGET) --release
build-release:
RUSTFLAGS=$(RUSTFLAGS) cargo $(TOOLCHAIN) build --target $(RUST_TARGET) --release
clean-release:
RUSTFLAGS=$(RUSTFLAGS) cargo $(TOOLCHAIN) clean --target $(RUST_TARGET) --release
test-release:
RUSTFLAGS=$(RUSTFLAGS) cargo $(TOOLCHAIN) test --target $(RUST_TARGET) --release
.PHONY: install
install:
RUSTFLAGS=$(RUSTFLAGS) cargo $(TOOLCHAIN) install --target $(RUST_TARGET) --path . --no-track --root $(INSTALL_DIR) --force

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@ -0,0 +1,5 @@
# 测试robust lock机制
此代码主要是用于测试:
1、robust lock机制中的两个系统调用是否能正常使用
2、当持有锁的线程异常终止时等待该锁的其他线程能够被通知到以避免死锁或数据不一样

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@ -0,0 +1,394 @@
extern crate libc;
extern crate syscalls;
use std::{
ffi::c_void,
mem::{self, size_of},
process,
ptr::{self, NonNull},
sync::atomic::{AtomicI32, Ordering},
thread,
time::Duration,
};
use syscalls::{
syscall0, syscall2, syscall3, syscall6,
Sysno::{futex, get_robust_list, gettid, set_robust_list},
};
use libc::{
c_int, mmap, perror, EXIT_FAILURE, MAP_ANONYMOUS, MAP_FAILED, MAP_SHARED, PROT_READ, PROT_WRITE,
};
const FUTEX_WAIT: usize = 0;
const FUTEX_WAKE: usize = 1;
// 封装futex
#[derive(Clone, Copy, Debug)]
struct Futex {
addr: *mut u32,
}
impl Futex {
pub fn new(addr: *mut u32) -> Self {
return Futex { addr };
}
pub fn get_addr(&self, offset: isize) -> *mut u32 {
return unsafe { self.addr.offset(offset) };
}
pub fn get_val(&self, offset: isize) -> u32 {
return unsafe { self.addr.offset(offset).read() };
}
pub fn set_val(&self, val: u32, offset: isize) {
unsafe {
self.addr.offset(offset).write(val);
}
}
}
unsafe impl Send for Futex {}
unsafe impl Sync for Futex {}
#[derive(Clone, Copy, Debug)]
struct Lock {
addr: *mut i32,
}
impl Lock {
pub fn new(addr: *mut i32) -> Self {
return Lock { addr };
}
pub fn get_val(&self, offset: isize) -> i32 {
return unsafe { self.addr.offset(offset).read() };
}
pub fn set_val(&self, val: i32, offset: isize) {
unsafe {
self.addr.offset(offset).write(val);
}
}
}
unsafe impl Send for Lock {}
unsafe impl Sync for Lock {}
#[derive(Debug, Clone, Copy)]
struct RobustList {
next: *const RobustList,
}
#[derive(Debug, Clone, Copy)]
struct RobustListHead {
list: RobustList,
/// 向kernel提供了要检查的futex字段的相对位置保持用户空间的灵活性可以自由
/// 地调整其数据结构,而无需向内核硬编码任何特定的偏移量
/// futexes中前面的地址是用来存入robust list中(list.next)后面是存放具体的futex val
/// 这个字段的作用就是从前面的地址偏移到后面的地址中从而获取futex val
#[allow(dead_code)]
futex_offset: isize,
/// 潜在的竞争条件:由于添加和删除列表是在获取锁之后进行的,这給线程留下了一个小窗口,在此期间可能会导致异常退出,
/// 从而使锁被悬挂为了防止这种可能性。用户空间还维护了一个简单的list_op_pending字段允许线程在获取锁后但还未添加到
/// 列表时就异常退出时进行清理。并且在完成列表添加或删除操作后将其清除
/// 这里没有测试这个在内核中实现实际上就是把list_op_pending地址进行一次唤醒如果有等待者
#[allow(dead_code)]
list_op_pending: *const RobustList,
}
fn error_handle(msg: &str) -> ! {
unsafe { perror(msg.as_ptr() as *const i8) };
process::exit(EXIT_FAILURE)
}
fn futex_wait(futexes: Futex, thread: &str, offset_futex: isize, lock: Lock, offset_count: isize) {
loop {
let atomic_count = AtomicI32::new(lock.get_val(offset_count));
if atomic_count
.compare_exchange(1, 0, Ordering::SeqCst, Ordering::SeqCst)
.is_ok()
{
lock.set_val(0, offset_count);
// 设置futex锁当前被哪个线程占用
let tid = unsafe { syscall0(gettid).unwrap() as u32 };
futexes.set_val(futexes.get_val(offset_futex) | tid, offset_futex);
break;
}
println!("{} wating...", thread);
let futex_val = futexes.get_val(offset_futex);
futexes.set_val(futex_val | 0x8000_0000, offset_futex);
let ret = unsafe {
syscall6(
futex,
futexes.get_addr(offset_futex) as usize,
FUTEX_WAIT,
futexes.get_val(offset_futex) as usize,
0,
0,
0,
)
};
if ret.is_err() {
error_handle("futex_wait failed");
}
// 被唤醒后释放锁
let atomic_count = AtomicI32::new(lock.get_val(offset_count));
if atomic_count
.compare_exchange(0, 1, Ordering::SeqCst, Ordering::SeqCst)
.is_ok()
{
lock.set_val(1, offset_count);
// 释放futex锁不被任何线程占用
futexes.set_val(futexes.get_val(offset_futex) & 0xc000_0000, offset_futex);
break;
}
}
}
fn futex_wake(futexes: Futex, thread: &str, offset_futex: isize, lock: Lock, offset_count: isize) {
let atomic_count = AtomicI32::new(lock.get_val(offset_count));
if atomic_count
.compare_exchange(0, 1, Ordering::SeqCst, Ordering::SeqCst)
.is_ok()
{
lock.set_val(1, offset_count);
// 释放futex锁不被任何线程占用
futexes.set_val(futexes.get_val(offset_futex) & 0xc000_0000, offset_futex);
// 如果没有线程/进程在等这个futex则不必唤醒, 释放改锁即可
let futex_val = futexes.get_val(offset_futex);
if futex_val & 0x8000_0000 == 0 {
return;
}
futexes.set_val(futex_val & !(1 << 31), offset_futex);
let ret = unsafe {
syscall6(
futex,
futexes.get_addr(offset_futex) as usize,
FUTEX_WAKE,
1,
0,
0,
0,
)
};
if ret.is_err() {
error_handle("futex wake failed");
}
println!("{} waked", thread);
}
}
fn set_list(futexes: Futex) {
let head = RobustListHead {
list: RobustList { next: ptr::null() },
futex_offset: 44,
list_op_pending: ptr::null(),
};
let head = NonNull::from(&head).as_ptr();
unsafe {
// 加入第一个futex
let head_ref_mut = &mut *head;
head_ref_mut.list.next = futexes.get_addr(0) as *const RobustList;
// 加入第二个futex
let list_2 = NonNull::from(&*head_ref_mut.list.next).as_ptr();
let list_2_ref_mut = &mut *list_2;
list_2_ref_mut.next = futexes.get_addr(1) as *const RobustList;
//println!("robust list next: {:?}", (*head).list.next );
//println!("robust list next next: {:?}", (*(*head).list.next).next );
// 向内核注册robust list
let len = mem::size_of::<*mut RobustListHead>();
let ret = syscall2(set_robust_list, head as usize, len);
if ret.is_err() {
println!("failed to set_robust_list, ret = {:?}", ret);
}
}
}
fn main() {
test01();
println!("-------------");
test02();
println!("-------------");
}
//测试set_robust_list和get_robust_list两个系统调用是否能正常使用
fn test01() {
// 创建robust list 头指针
let head = RobustListHead {
list: RobustList { next: ptr::null() },
futex_offset: 8,
list_op_pending: ptr::null(),
};
let head = NonNull::from(&head).as_ptr();
let futexes = unsafe {
mmap(
ptr::null_mut::<c_void>(),
(size_of::<c_int>() * 2) as libc::size_t,
PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_SHARED,
-1,
0,
) as *mut u32
};
if futexes == MAP_FAILED as *mut u32 {
error_handle("futexes_addr mmap failed");
}
unsafe {
futexes.offset(11).write(0x0000_0000);
futexes.offset(12).write(0x8000_0000);
println!("futex1 next addr: {:?}", futexes.offset(0));
println!("futex2 next addr: {:?}", futexes.offset(1));
println!("futex1 val addr: {:?}", futexes.offset(11));
println!("futex2 val addr: {:?}", futexes.offset(12));
println!("futex1 val: {:#x?}", futexes.offset(11).read());
println!("futex2 val: {:#x?}", futexes.offset(12).read());
}
// 打印注册之前的robust list
println!("robust list next(get behind): {:?}", &unsafe { *head });
unsafe {
let head_ref_mut = &mut *head;
head_ref_mut.list.next = futexes.offset(0) as *const RobustList;
let list_2 = NonNull::from(&*head_ref_mut.list.next).as_ptr();
let list_2_ref_mut = &mut *list_2;
list_2_ref_mut.next = futexes.offset(1) as *const RobustList;
println!("robust list next addr: {:?}", (*head).list.next);
println!(
"robust list next next addr: {:?}",
(*(*head).list.next).next
);
}
unsafe {
let len = mem::size_of::<*mut RobustListHead>();
let ret = syscall2(set_robust_list, head as usize, len);
if ret.is_err() {
println!("failed to set_robust_list, ret = {:?}", ret);
}
}
println!("get before, set after: {:?}", head);
println!("get before, set after: {:?}", &unsafe { *head });
unsafe {
let len: usize = 0;
println!("len = {}", len);
let len_ptr = NonNull::from(&len).as_ptr();
let ret = syscall3(get_robust_list, 0, head as usize, len_ptr as usize);
println!("get len = {}", len);
if ret.is_err() {
println!("failed to get_robust_list, ret = {:?}", ret);
}
println!("futex1 val: {:#x}", futexes.offset(11).read());
println!("futex2 val: {:#x}", futexes.offset(12).read());
println!("robust list next: {:?}", futexes.offset(0));
println!("robust list next next: {:#x?}", futexes.offset(0).read());
}
println!("robust list head(get after): {:?}", head);
println!("robust list next(get after): {:?}", &unsafe { *head });
}
//测试一个线程异常退出时futex的robustness(多线程测试目前futex还不支持多进程)
fn test02() {
let futexes = unsafe {
mmap(
ptr::null_mut::<c_void>(),
(size_of::<c_int>() * 2) as libc::size_t,
PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_SHARED,
-1,
0,
) as *mut u32
};
if futexes == MAP_FAILED as *mut u32 {
error_handle("mmap failed");
}
let count = unsafe {
mmap(
ptr::null_mut::<c_void>(),
(size_of::<c_int>() * 2) as libc::size_t,
PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_SHARED,
-1,
0,
) as *mut i32
};
if count == MAP_FAILED as *mut i32 {
error_handle("mmap failed");
}
unsafe {
// 在这个示例中第一段和第二段地址放入robust list第11段地址和第12段地址存放futex val
futexes.offset(11).write(0x0000_0000);
futexes.offset(12).write(0x0000_0000);
println!("futex1 next addr: {:?}", futexes.offset(0));
println!("futex2 next addr: {:?}", futexes.offset(1));
println!("futex1 val addr: {:?}", futexes.offset(11));
println!("futex2 val addr: {:?}", futexes.offset(12));
println!("futex1 val: {:#x?}", futexes.offset(11).read());
println!("futex2 val: {:#x?}", futexes.offset(12).read());
count.offset(0).write(1);
count.offset(1).write(0);
println!("count1 val: {:?}", count.offset(0).read());
println!("count2 val: {:?}", count.offset(1).read());
}
let futexes = Futex::new(futexes);
let locks = Lock::new(count);
// tid1 = 7
let thread1 = thread::spawn(move || {
set_list(futexes);
thread::sleep(Duration::from_secs(2));
for i in 0..2 {
futex_wait(futexes, "thread1", 11, locks, 0);
println!("thread1 times: {}", i);
thread::sleep(Duration::from_secs(3));
let tid = unsafe { syscall0(gettid).unwrap() as u32 };
futexes.set_val(futexes.get_val(12) | tid, 12);
if i == 1 {
// 让thread1异常退出从而无法唤醒thread2,检测robustness
println!("Thread1 exiting early due to simulated error.");
return;
}
futex_wake(futexes, "thread2", 12, locks, 1);
}
});
// tid2 = 6
set_list(futexes);
for i in 0..2 {
futex_wait(futexes, "thread2", 12, locks, 1);
println!("thread2 times: {}", i);
let tid = unsafe { syscall0(gettid).unwrap() as u32 };
futexes.set_val(futexes.get_val(11) | tid, 11);
futex_wake(futexes, "thread1", 11, locks, 0);
}
thread1.join().unwrap();
}

View File

@ -0,0 +1,24 @@
{
"name": "test-for-robustfutex",
"version": "0.1.0",
"description": "some tests for robust futex",
"rust_target": null,
"task_type": {
"BuildFromSource": {
"Local": {
"path": "apps/test-for-robustfutex"
}
}
},
"depends": [],
"build": {
"build_command": "make install"
},
"install": {
"in_dragonos_path": "/"
},
"clean": {
"clean_command": "make clean"
},
"envs": []
}