Add syscall mknod

Signed-off-by: Zhenchen Wang <m202372036@hust.edu.cn>

docs/src/kernel/linux-compatibility.md

@@ -153,7 +153,9 @@ provided by Linux on x86-64 architecture.
 | 130     | rt_sigsuspend    | ✅              |
 | 131     | sigaltstack      | ✅              |
 | 132     | utime            | ✅              |
-| 133     | mknod            | ❌              |
+| 133     | mknod            | ✅              |
+| 132     | utime            | ❌              |
+| 133     | mknod            | ✅              |
 | 134     | uselib           | ❌              |
 | 135     | personality      | ❌              |
 | 136     | ustat            | ❌              |
@@ -279,7 +281,7 @@ provided by Linux on x86-64 architecture.
 | 256     | migrate_pages    | ❌              |
 | 257     | openat           | ✅              |
 | 258     | mkdirat          | ✅              |
-| 259     | mknodat          | ❌              |
+| 259     | mknodat          | ✅              |
 | 260     | fchownat         | ✅              |
 | 261     | futimesat        | ✅              |
 | 262     | newfstatat       | ✅              |

kernel/aster-nix/src/device/mod.rs

@@ -47,3 +47,20 @@ pub fn init() -> Result<()> {
     pty::init()?;
     Ok(())
 }
+
+pub fn get_device(dev: usize) -> Result<Arc<dyn Device>> {
+    if dev == 0 {
+        return_errno_with_message!(Errno::EPERM, "whiteout device")
+    }
+    let major = ((dev >> 32) & 0xffff_f000 | (dev >> 8) & 0x0000_0fff) as u32;
+    let minor = ((dev >> 12) & 0xffff_ff00 | dev & 0x0000_00ff) as u32;
+
+    match (major, minor) {
+        (1, 3) => Ok(Arc::new(null::Null)),
+        (1, 5) => Ok(Arc::new(zero::Zero)),
+        (5, 0) => Ok(Arc::new(tty::TtyDevice)),
+        (1, 8) => Ok(Arc::new(random::Random)),
+        (1, 9) => Ok(Arc::new(urandom::Urandom)),
+        _ => return_errno_with_message!(Errno::EINVAL, "unsupported device"),
+    }
+}

kernel/aster-nix/src/syscall/arch/x86.rs

@@ -55,6 +55,7 @@ use crate::syscall::{
     lseek::sys_lseek,
     madvise::sys_madvise,
     mkdir::{sys_mkdir, sys_mkdirat},
+    mknod::{sys_mknod, sys_mknodat},
     mmap::sys_mmap,
     mount::sys_mount,
     mprotect::sys_mprotect,
@@ -236,6 +237,7 @@ impl_syscall_nums_and_dispatch_fn! {
     SYS_RT_SIGSUSPEND = 130    => sys_rt_sigsuspend(args[..2]);
     SYS_SIGALTSTACK = 131      => sys_sigaltstack(args[..2]);
     SYS_UTIME = 132            => sys_utime(args[..2]);
+    SYS_MKNOD = 133            => sys_mknod(args[..3]);
     SYS_STATFS = 137           => sys_statfs(args[..2]);
     SYS_FSTATFS = 138          => sys_fstatfs(args[..2]);
     SYS_GET_PRIORITY = 140     => sys_get_priority(args[..2]);
@@ -267,6 +269,7 @@ impl_syscall_nums_and_dispatch_fn! {
     SYS_WAITID = 247           => sys_waitid(args[..5]);
     SYS_OPENAT = 257           => sys_openat(args[..4]);
     SYS_MKDIRAT = 258          => sys_mkdirat(args[..3]);
+    SYS_MKNODAT = 259          => sys_mknodat(args[..4]);
     SYS_FCHOWNAT = 260         => sys_fchownat(args[..5]);
     SYS_FUTIMESAT = 261        => sys_futimesat(args[..3]);
     SYS_FSTATAT = 262          => sys_fstatat(args[..4]);

kernel/aster-nix/src/syscall/mknod.rs

@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: MPL-2.0
+
+use super::SyscallReturn;
+use crate::{
+    device::get_device,
+    fs::{
+        file_table::FileDesc,
+        fs_resolver::{FsPath, AT_FDCWD},
+        utils::{InodeMode, InodeType},
+    },
+    prelude::*,
+    syscall::{constants::MAX_FILENAME_LEN, stat::FileTypeFlags},
+    util::read_cstring_from_user,
+};
+
+pub fn sys_mknodat(
+    dirfd: FileDesc,
+    path_addr: Vaddr,
+    mode: u16,
+    dev: usize,
+) -> Result<SyscallReturn> {
+    let path = read_cstring_from_user(path_addr, MAX_FILENAME_LEN)?;
+    let current = current!();
+    let inode_mode = {
+        let mask_mode = mode & !current.umask().read().get();
+        InodeMode::from_bits_truncate(mask_mode)
+    };
+    let file_type = FileTypeFlags::from_bits_truncate(mode);
+    debug!(
+        "dirfd = {}, path = {:?}, inode_mode = {:?}, file_type = {:?}, dev = {}",
+        dirfd, path, inode_mode, file_type, dev
+    );
+
+    let (dir_dentry, name) = {
+        let path = path.to_string_lossy();
+        if path.is_empty() {
+            return_errno_with_message!(Errno::ENOENT, "path is empty");
+        }
+        let fs_path = FsPath::new(dirfd, path.as_ref())?;
+        current.fs().read().lookup_dir_and_base_name(&fs_path)?
+    };
+
+    if file_type.contains(FileTypeFlags::S_IFREG) || file_type.is_empty() {
+        let _ = dir_dentry.new_fs_child(name.trim_end_matches('/'), InodeType::File, inode_mode)?;
+    } else if file_type.contains(FileTypeFlags::S_IFCHR)
+        || file_type.contains(FileTypeFlags::S_IFBLK)
+    {
+        let _ = dir_dentry.mknod(name.trim_end_matches('/'), inode_mode, get_device(dev)?)?;
+    } else if file_type.contains(FileTypeFlags::S_IFIFO)
+        || file_type.contains(FileTypeFlags::S_IFSOCK)
+    {
+        return_errno_with_message!(Errno::EINVAL, "unsupported file type flag");
+    } else {
+        return_errno_with_message!(Errno::EPERM, "unimplemented types");
+    }
+
+    Ok(SyscallReturn::Return(0))
+}
+
+pub fn sys_mknod(path_addr: Vaddr, mode: u16, dev: usize) -> Result<SyscallReturn> {
+    self::sys_mknodat(AT_FDCWD, path_addr, mode, dev)
+}

kernel/aster-nix/src/syscall/mod.rs

@@ -62,6 +62,7 @@ mod listen;
 mod lseek;
 mod madvise;
 mod mkdir;
+mod mknod;
 mod mmap;
 mod mount;
 mod mprotect;

kernel/aster-nix/src/syscall/stat.rs

@@ -77,11 +77,19 @@ pub fn sys_fstatat(
     Ok(SyscallReturn::Return(0))
 }
 
-pub const S_IFMT: u32 = 0o170000;
+bitflags! {
-pub const S_IFCHR: u32 = 0o020000;
+    /// File type.
-pub const S_IFDIR: u32 = 0o040000;
+    pub struct FileTypeFlags: u16 {
-pub const S_IFREG: u32 = 0o100000;
+        const S_IFMT   = 0o170000; // File type mask.
-pub const S_IFLNK: u32 = 0o120000;
+        const S_IFSOCK = 0o140000; // Socket.
+        const S_IFCHR  = 0o020000; // Character device.
+        const S_IFBLK  = 0o060000; // Block device.
+        const S_IFDIR  = 0o040000; // Directory.
+        const S_IFIFO  = 0o010000; // FIFO (named pipe).
+        const S_IFREG  = 0o100000; // Regular file.
+        const S_IFLNK  = 0o120000; // Symbolic link.
+    }
+}
 
 /// File Stat
 #[derive(Debug, Clone, Copy, Pod, Default)]

test/syscall_test/Makefile

@@ -20,6 +20,7 @@ TESTS ?= \
 	link_test \
 	lseek_test \
 	mkdir_test \
+	mknod_test \
 	mmap_test \
 	mount_test \
 	open_create_test \

test/syscall_test/blocklists.exfat/mknod_test

@@ -0,0 +1 @@
+MknodTest.RegularFilePermissions

test/syscall_test/blocklists/mknod_test

@@ -0,0 +1,6 @@
+MknodTest.MknodAtFIFO
+MknodTest.MknodOnExistingPathFails
+MknodTest.Socket
+MknodTest.Fifo
+MknodTest.FifoOtrunc
+MknodTest.FifoTruncNoOp