新增系统调用，并对照linux-6.1.9改写sys_wait4 (DragonOS-Community#440)

* 1. 新增以下系统调用
            - SYS_LSTAT
            - SYS_READV
            - SYS_ACCESS
            - SYS_UNLINK
            - SYS_CHMOD
            - SYS_FCHMOD
            - SYS_UMASK
            - SYS_SYSINFO
            - SYS_CLOCK_GETTIME
            - SYS_FCHMODAT
            - SYS_FACCESSAT

2. 修改sys_wait4,使得其部分符合Linux的行为(还是有些地方不符合的,详情请对比linux-6.1.9的sys_wait4接口)

kernel/src/arch/x86_64/ipc/signal.rs

@@ -277,6 +277,42 @@ bitflags! {
     }
 }
 
+/// SIGCHLD si_codes
+#[derive(Debug, Clone, Copy, PartialEq, Eq, ToPrimitive)]
+#[allow(dead_code)]
+pub enum SigChildCode {
+    /// child has exited
+    ///
+    /// CLD_EXITED
+    Exited = 1,
+    /// child was killed
+    ///
+    /// CLD_KILLED
+    Killed = 2,
+    /// child terminated abnormally
+    ///
+    /// CLD_DUMPED
+    Dumped = 3,
+    /// traced child has trapped
+    ///
+    /// CLD_TRAPPED
+    Trapped = 4,
+    /// child has stopped
+    ///
+    /// CLD_STOPPED
+    Stopped = 5,
+    /// stopped child has continued
+    ///
+    /// CLD_CONTINUED
+    Continued = 6,
+}
+
+impl Into<i32> for SigChildCode {
+    fn into(self) -> i32 {
+        self as i32
+    }
+}
+
 #[repr(C, align(16))]
 #[derive(Debug, Clone, Copy)]
 pub struct SigFrame {

kernel/src/arch/x86_64/process/syscall.rs

@@ -22,15 +22,16 @@ impl Syscall {
         envp: Vec<String>,
         regs: &mut TrapFrame,
     ) -> Result<(), SystemError> {
-        // kdebug!(
-        //     "tmp_rs_execve: path: {:?}, argv: {:?}, envp: {:?}\n",
+        // 关中断，防止在设置地址空间的时候，发生中断，然后进调度器，出现错误。
+        let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() };
+        let pcb = ProcessManager::current_pcb();
+        // crate::kdebug!(
+        //     "pid: {:?}  do_execve: path: {:?}, argv: {:?}, envp: {:?}\n",
+        //     pcb.pid(),
         //     path,
         //     argv,
         //     envp
         // );
-        // 关中断，防止在设置地址空间的时候，发生中断，然后进调度器，出现错误。
-        let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() };
-        let pcb = ProcessManager::current_pcb();
 
         let mut basic_info = pcb.basic_mut();
         // 暂存原本的用户地址空间的引用(因为如果在切换页表之前释放了它，可能会造成内存use after free)
@@ -109,7 +110,7 @@ impl Syscall {
 
         // kdebug!("regs: {:?}\n", regs);
 
-        // kdebug!(
+        // crate::kdebug!(
         //     "tmp_rs_execve: done, load_result.entry_point()={:?}",
         //     load_result.entry_point()
         // );

kernel/src/arch/x86_64/syscall.rs

@@ -7,15 +7,25 @@ use crate::{
     ipc::signal_types::SignalArch,
     libs::align::SafeForZero,
     mm::VirtAddr,
+    process::ProcessManager,
     syscall::{Syscall, SystemError, SYS_RT_SIGRETURN},
 };
 use alloc::string::String;
 
 use super::{interrupt::TrapFrame, mm::barrier::mfence};
 
+pub const SYS_LSTAT: usize = 6;
+pub const SYS_READV: usize = 19;
 pub const SYS_ACCESS: usize = 21;
-pub const SYS_PRLIMIT64: usize = 302;
+pub const SYS_UNLINK: usize = 87;
+pub const SYS_CHMOD: usize = 90;
+pub const SYS_FCHMOD: usize = 91;
+pub const SYS_UMASK: usize = 95;
+pub const SYS_SYSINFO: usize = 99;
+pub const SYS_CLOCK_GETTIME: usize = 228;
+pub const SYS_FCHMODAT: usize = 268;
 pub const SYS_FACCESSAT: usize = 269;
+pub const SYS_PRLIMIT64: usize = 302;
 pub const SYS_FACCESSAT2: usize = 439;
 
 /// ### 存储PCB系统调用栈以及在syscall过程中暂存用户态rsp的结构体
@@ -44,9 +54,15 @@ extern "C" {
 }
 
 macro_rules! syscall_return {
-    ($val:expr, $regs:expr) => {{
+    ($val:expr, $regs:expr, $show:expr) => {{
         let ret = $val;
         $regs.rax = ret as u64;
+
+        if $show {
+            let pid = ProcessManager::current_pcb().pid();
+            crate::kdebug!("syscall return:pid={:?},ret= {:?}\n", pid, ret as isize);
+        }
+
         unsafe {
             CurrentIrqArch::interrupt_disable();
         }
@@ -69,18 +85,34 @@ pub extern "sysv64" fn syscall_handler(frame: &mut TrapFrame) -> () {
         frame.r9 as usize,
     ];
     mfence();
+    let pid = ProcessManager::current_pcb().pid();
+    let show = false;
+    // let show = if syscall_num != SYS_SCHED && pid.data() > 3 {
+    //     true
+    // } else {
+    //     false
+    // };
+
+    if show {
+        crate::kdebug!("syscall: pid: {:?}, num={:?}\n", pid, syscall_num);
+    }
 
     // Arch specific syscall
     match syscall_num {
         SYS_RT_SIGRETURN => {
-            syscall_return!(X86_64SignalArch::sys_rt_sigreturn(frame) as usize, frame);
+            syscall_return!(
+                X86_64SignalArch::sys_rt_sigreturn(frame) as usize,
+                frame,
+                show
+            );
         }
         _ => {}
     }
     syscall_return!(
         Syscall::handle(syscall_num, &args, frame).unwrap_or_else(|e| e.to_posix_errno() as usize)
             as u64,
-        frame
+        frame,
+        show
     );
 }
 

kernel/src/filesystem/vfs/core.rs

@@ -16,10 +16,15 @@ use crate::{
         vfs::{mount::MountFS, syscall::ModeType, AtomicInodeId, FileSystem, FileType},
     },
     kdebug, kerror, kinfo,
+    process::ProcessManager,
     syscall::SystemError,
 };
 
-use super::{file::FileMode, utils::rsplit_path, IndexNode, InodeId, MAX_PATHLEN};
+use super::{
+    file::FileMode,
+    utils::{rsplit_path, user_path_at},
+    IndexNode, InodeId, MAX_PATHLEN, VFS_MAX_FOLLOW_SYMLINK_TIMES,
+};
 
 /// @brief 原子地生成新的Inode号。
 /// 请注意，所有的inode号都需要通过该函数来生成.全局的inode号，除了以下两个特殊的以外，都是唯一的
@@ -206,13 +211,17 @@ pub fn do_mkdir(path: &str, _mode: FileMode) -> Result<u64, SystemError> {
 }
 
 /// @brief 删除文件夹
-pub fn do_remove_dir(path: &str) -> Result<u64, SystemError> {
+pub fn do_remove_dir(dirfd: i32, path: &str) -> Result<u64, SystemError> {
     // 文件名过长
     if path.len() > MAX_PATHLEN as usize {
         return Err(SystemError::ENAMETOOLONG);
     }
 
-    let inode: Result<Arc<dyn IndexNode>, SystemError> = ROOT_INODE().lookup(path);
+    let pcb = ProcessManager::current_pcb();
+    let (inode_begin, remain_path) = user_path_at(&pcb, dirfd, path.to_string())?;
+
+    let inode: Result<Arc<dyn IndexNode>, SystemError> =
+        inode_begin.lookup_follow_symlink(remain_path.as_str(), VFS_MAX_FOLLOW_SYMLINK_TIMES);
 
     if inode.is_err() {
         let errno = inode.unwrap_err();
@@ -222,9 +231,10 @@ pub fn do_remove_dir(path: &str) -> Result<u64, SystemError> {
         }
     }
 
-    let (filename, parent_path) = rsplit_path(path);
+    let (filename, parent_path) = rsplit_path(&remain_path);
     // 查找父目录
-    let parent_inode: Arc<dyn IndexNode> = ROOT_INODE().lookup(parent_path.unwrap_or("/"))?;
+    let parent_inode: Arc<dyn IndexNode> = inode_begin
+        .lookup_follow_symlink(parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?;
 
     if parent_inode.metadata()?.file_type != FileType::Dir {
         return Err(SystemError::ENOTDIR);
@@ -242,13 +252,16 @@ pub fn do_remove_dir(path: &str) -> Result<u64, SystemError> {
 }
 
 /// @brief 删除文件
-pub fn do_unlink_at(path: &str, _mode: FileMode) -> Result<u64, SystemError> {
+pub fn do_unlink_at(dirfd: i32, path: &str) -> Result<u64, SystemError> {
     // 文件名过长
     if path.len() > MAX_PATHLEN as usize {
         return Err(SystemError::ENAMETOOLONG);
     }
+    let pcb = ProcessManager::current_pcb();
+    let (inode_begin, remain_path) = user_path_at(&pcb, dirfd, path.to_string())?;
 
-    let inode: Result<Arc<dyn IndexNode>, SystemError> = ROOT_INODE().lookup(path);
+    let inode: Result<Arc<dyn IndexNode>, SystemError> =
+        inode_begin.lookup_follow_symlink(&remain_path, VFS_MAX_FOLLOW_SYMLINK_TIMES);
 
     if inode.is_err() {
         let errno = inode.clone().unwrap_err();
@@ -264,7 +277,8 @@ pub fn do_unlink_at(path: &str, _mode: FileMode) -> Result<u64, SystemError> {
 
     let (filename, parent_path) = rsplit_path(path);
     // 查找父目录
-    let parent_inode: Arc<dyn IndexNode> = ROOT_INODE().lookup(parent_path.unwrap_or("/"))?;
+    let parent_inode: Arc<dyn IndexNode> = inode_begin
+        .lookup_follow_symlink(parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?;
 
     if parent_inode.metadata()?.file_type != FileType::Dir {
         return Err(SystemError::ENOTDIR);

kernel/src/filesystem/vfs/file.rs

@@ -19,6 +19,7 @@ use super::{Dirent, FileType, IndexNode, InodeId, Metadata, SpecialNodeData};
 
 /// 文件私有信息的枚举类型
 #[derive(Debug, Clone)]
+#[allow(dead_code)]
 pub enum FilePrivateData {
     /// 管道文件私有信息
     Pipefs(PipeFsPrivateData),
@@ -198,6 +199,7 @@ impl File {
     }
 
     /// @brief 根据inode号获取子目录项的名字
+    #[allow(dead_code)]
     pub fn get_entry_name(&self, ino: InodeId) -> Result<String, SystemError> {
         return self.inode.get_entry_name(ino);
     }
@@ -535,6 +537,7 @@ impl FileDescriptorVec {
         return Ok(());
     }
 
+    #[allow(dead_code)]
     pub fn iter(&self) -> FileDescriptorIterator {
         return FileDescriptorIterator::new(self);
     }

kernel/src/filesystem/vfs/mod.rs

@@ -1,5 +1,3 @@
-#![allow(dead_code)]
-
 pub mod core;
 pub mod fcntl;
 pub mod file;
@@ -50,6 +48,7 @@ pub enum FileType {
     Socket,
 }
 
+#[allow(dead_code)]
 #[derive(Debug, Clone)]
 pub enum SpecialNodeData {
     /// 管道文件
@@ -62,6 +61,7 @@ pub enum SpecialNodeData {
 
 /* these are defined by POSIX and also present in glibc's dirent.h */
 /// 完整含义请见 http://www.gnu.org/software/libc/manual/html_node/Directory-Entries.html
+#[allow(dead_code)]
 pub const DT_UNKNOWN: u16 = 0;
 /// 命名管道，或者FIFO
 pub const DT_FIFO: u16 = 1;
@@ -78,7 +78,9 @@ pub const DT_LNK: u16 = 10;
 // 是一个socket
 pub const DT_SOCK: u16 = 12;
 // 这个是抄Linux的，还不知道含义
+#[allow(dead_code)]
 pub const DT_WHT: u16 = 14;
+#[allow(dead_code)]
 pub const DT_MAX: u16 = 16;
 
 /// vfs容许的最大的符号链接跳转次数

kernel/src/filesystem/vfs/open.rs

@@ -1,14 +1,20 @@
-use crate::syscall::SystemError;
+use crate::{
+    process::ProcessManager,
+    syscall::{user_access::check_and_clone_cstr, SystemError},
+};
 
-use super::{fcntl::AtFlags, syscall::ModeType};
+use super::{
+    fcntl::AtFlags, syscall::ModeType, utils::user_path_at, MAX_PATHLEN,
+    VFS_MAX_FOLLOW_SYMLINK_TIMES,
+};
 
 pub(super) fn do_faccessat(
-    _dirfd: i32,
-    _pathname: *const u8,
+    dirfd: i32,
+    path: *const u8,
     mode: ModeType,
     flags: u32,
 ) -> Result<usize, SystemError> {
-    if (mode.bits() & (!ModeType::S_IXUGO.bits())) != 0 {
+    if (mode.bits() & (!ModeType::S_IRWXO.bits())) != 0 {
         return Err(SystemError::EINVAL);
     }
 
@@ -22,6 +28,35 @@ pub(super) fn do_faccessat(
 
     // let follow_symlink = flags & AtFlags::AT_SYMLINK_NOFOLLOW.bits() as u32 == 0;
 
+    let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?;
+
+    if path.len() == 0 {
+        return Err(SystemError::EINVAL);
+    }
+
+    let (inode, path) = user_path_at(&ProcessManager::current_pcb(), dirfd, path)?;
+
+    // 如果找不到文件，则返回错误码ENOENT
+    let _inode = inode.lookup_follow_symlink(path.as_str(), VFS_MAX_FOLLOW_SYMLINK_TIMES)?;
+
     // todo: 接着完善（可以借鉴linux 6.1.9的do_faccessat）
     return Ok(0);
 }
+
+pub fn do_fchmodat(dirfd: i32, path: *const u8, _mode: ModeType) -> Result<usize, SystemError> {
+    let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?;
+
+    if path.len() == 0 {
+        return Err(SystemError::EINVAL);
+    }
+
+    let (inode, path) = user_path_at(&ProcessManager::current_pcb(), dirfd, path)?;
+
+    // 如果找不到文件，则返回错误码ENOENT
+    let _inode = inode.lookup_follow_symlink(path.as_str(), VFS_MAX_FOLLOW_SYMLINK_TIMES)?;
+
+    kwarn!("do_fchmodat: not implemented yet\n");
+    // todo: 真正去改变文件的权限
+
+    return Ok(0);
+}