feature: shell exec

Makefile

@@ -95,6 +95,7 @@ initrd:
 	mkdir -p $(O)/rootfs/bin
 	cp target/$(ARCH)-osdev5/$(PROFILE)/init $(O)/rootfs/init
 	cp target/$(ARCH)-osdev5/$(PROFILE)/shell $(O)/rootfs/bin
+	cp target/$(ARCH)-osdev5/$(PROFILE)/fuzzy $(O)/rootfs/bin
 	cd $(O)/rootfs && tar cf ../initrd.img `find -type f -printf "%P\n"`
 ifeq ($(MACH),orangepi3)
 	$(MKIMAGE) \

fs/memfs/src/lib.rs

@@ -29,7 +29,7 @@ pub use block::{BlockAllocator, BlockRef};
 mod bvec;
 use bvec::Bvec;
 mod tar;
-use tar::TarIterator;
+use tar::{TarIterator, Tar};
 mod file;
 use file::FileInode;
 mod dir;
@@ -67,8 +67,10 @@ impl<A: BlockAllocator + Copy + 'static> Ramfs<A> {
         Ok(res)
     }
 
-    fn create_node_initial(self: Rc<Self>, name: &str, kind: VnodeKind) -> VnodeRef {
+    fn create_node_initial(self: Rc<Self>, name: &str, tar: &Tar) -> VnodeRef {
+        let kind = tar.node_kind();
         let node = Vnode::new(name, kind, Vnode::SEEKABLE);
+        node.props_mut().mode = tar.mode();
         node.set_fs(self.clone());
         match kind {
             VnodeKind::Directory => node.set_data(Box::new(DirInode::new(self.alloc))),
@@ -111,7 +113,10 @@ impl<A: BlockAllocator + Copy + 'static> Ramfs<A> {
     }
 
     unsafe fn load_tar(self: Rc<Self>, base: *const u8, size: usize) -> Result<VnodeRef, Errno> {
-        let root = self.clone().create_node_initial("", VnodeKind::Directory);
+        let root = Vnode::new("", VnodeKind::Directory, Vnode::SEEKABLE);
+        root.set_fs(self.clone());
+        root.set_data(Box::new(DirInode::new(self.alloc)));
+        root.props_mut().mode = FileMode::default_dir();
 
         // 1. Create all the paths in TAR
         for block in TarIterator::new(base, base.add(size)) {
@@ -120,7 +125,7 @@ impl<A: BlockAllocator + Copy + 'static> Ramfs<A> {
             let parent = self.clone().make_path(root.clone(), dirname, true)?;
             let node = self
                 .clone()
-                .create_node_initial(basename, block.node_kind());
+                .create_node_initial(basename, block);
             assert_eq!(node.kind(), block.node_kind());
             parent.attach(node);
         }

fs/memfs/src/tar.rs

@@ -1,4 +1,4 @@
-use libsys::error::Errno;
+use libsys::{error::Errno, stat::FileMode};
 use vfs::VnodeKind;
 
 #[repr(packed)]
@@ -81,6 +81,10 @@ impl Tar {
         }
     }
 
+    pub fn mode(&self) -> FileMode {
+        FileMode::from_bits(from_octal(&self.mode) as u32).unwrap()
+    }
+
     pub fn data(&self) -> &[u8] {
         unsafe {
             core::slice::from_raw_parts(

fs/vfs/src/node.rs

@@ -1,11 +1,11 @@
-use crate::{File, FileRef, Filesystem};
+use crate::{Ioctx, File, FileRef, Filesystem};
 use alloc::{borrow::ToOwned, boxed::Box, rc::Rc, string::String, vec::Vec};
 use core::cell::{RefCell, RefMut};
 use core::fmt;
 use libsys::{
     error::Errno,
     ioctl::IoctlCmd,
-    stat::{FileMode, OpenFlags, Stat},
+    stat::{AccessMode, FileMode, OpenFlags, Stat},
 };
 
 /// Convenience type alias for [Rc<Vnode>]
@@ -31,7 +31,7 @@ pub(crate) struct TreeNode {
 
 /// File property cache struct
 pub struct VnodeProps {
-    mode: FileMode,
+    pub mode: FileMode,
 }
 
 /// Virtual filesystem node struct, generalizes access to
@@ -122,6 +122,11 @@ impl Vnode {
         &self.name
     }
 
+    /// Returns a borrowed reference to cached file properties
+    pub fn props_mut(&self) -> RefMut<VnodeProps> {
+        self.props.borrow_mut()
+    }
+
     /// Sets an associated [VnodeImpl] for the [Vnode]
     pub fn set_data(&self, data: Box<dyn VnodeImpl>) {
         *self.data.borrow_mut() = Some(data);
@@ -408,6 +413,38 @@ impl Vnode {
             Err(Errno::NotImplemented)
         }
     }
+
+    pub fn check_access(&self, ioctx: &Ioctx, access: AccessMode) -> Result<(), Errno> {
+        let props = self.props.borrow();
+        let mode = props.mode;
+
+        if access.contains(AccessMode::F_OK) {
+            if access.intersects(AccessMode::R_OK | AccessMode::W_OK | AccessMode::X_OK) {
+                return Err(Errno::InvalidArgument);
+            }
+            return Ok(());
+        } else {
+            if access.contains(AccessMode::F_OK) {
+                return Err(Errno::InvalidArgument);
+            }
+
+            // Check user
+            if access.contains(AccessMode::R_OK) && !mode.contains(FileMode::USER_READ) {
+                return Err(Errno::PermissionDenied);
+            }
+            if access.contains(AccessMode::W_OK) && !mode.contains(FileMode::USER_WRITE) {
+                return Err(Errno::PermissionDenied);
+            }
+            if access.contains(AccessMode::X_OK) && !mode.contains(FileMode::USER_EXEC) {
+                return Err(Errno::PermissionDenied);
+            }
+
+            // TODO check group
+            // TODO check other
+
+            return Ok(());
+        }
+    }
 }
 
 impl fmt::Debug for Vnode {

kernel/src/proc/process.rs

@@ -243,7 +243,9 @@ impl Process {
 
             if lock.threads.len() == 1 {
                 // TODO call Process::exit instead?
-                todo!();
+                drop(lock);
+                Process::exit(ExitCode::from(0));
+                panic!();
             }
 
             lock.threads.retain(|&e| e != tid);

kernel/src/proc/thread.rs

@@ -283,7 +283,7 @@ impl Thread {
     }
 
     /// Switches process main thread to a signal handler
-    pub fn enter_signal(&self, signal: Signal, ttbr0: usize) {
+    pub fn enter_signal(self: ThreadRef, signal: Signal, ttbr0: usize) {
         if self
             .signal_pending
             .compare_exchange_weak(0, signal as u32, Ordering::SeqCst, Ordering::Relaxed)
@@ -294,7 +294,9 @@ impl Thread {
 
         let mut lock = self.inner.lock();
         if lock.signal_entry == 0 || lock.signal_stack == 0 {
-            todo!();
+            drop(lock);
+            Process::exit_thread(self);
+            panic!();
         }
 
         let signal_ctx = unsafe { &mut *self.signal_ctx.get() };

kernel/src/syscall/mod.rs

@@ -12,7 +12,7 @@ use libsys::{
     ioctl::IoctlCmd,
     proc::Pid,
     signal::{Signal, SignalDestination},
-    stat::{FdSet, FileDescriptor, FileMode, OpenFlags, Stat, AT_EMPTY_PATH},
+    stat::{FdSet, AccessMode, FileDescriptor, FileMode, OpenFlags, Stat, AT_EMPTY_PATH},
     traits::{Read, Write},
 };
 use vfs::VnodeRef;
@@ -233,6 +233,18 @@ pub fn syscall(num: usize, args: &[usize]) -> Result<usize, Errno> {
 
             wait::select(Thread::current(), rfds, wfds, timeout)
         }
+        abi::SYS_FACCESSAT => {
+            let at_fd = FileDescriptor::from_i32(args[0] as i32)?;
+            let path = validate_user_str(args[1], args[2])?;
+            let mode = AccessMode::from_bits(args[3] as u32).ok_or(Errno::InvalidArgument)?;
+            let flags = args[4] as u32;
+
+            let proc = Process::current();
+            let mut io = proc.io.lock();
+
+            find_at_node(&mut io, at_fd, path, flags & AT_EMPTY_PATH != 0)?.check_access(io.ioctx(), mode)?;
+            Ok(0)
+        },
 
         _ => {
             let thread = Thread::current();

libsys/src/abi.rs

@@ -20,3 +20,4 @@ pub const SYS_EXECVE: usize = 8;
 pub const SYS_WAITPID: usize = 9;
 pub const SYS_IOCTL: usize = 10;
 pub const SYS_SELECT: usize = 11;
+pub const SYS_FACCESSAT: usize = 12;

libsys/src/calls.rs

@@ -4,7 +4,7 @@ use crate::{
     ioctl::IoctlCmd,
     proc::{ExitCode, Pid},
     signal::{Signal, SignalDestination},
-    stat::{FdSet, FileDescriptor, FileMode, OpenFlags, Stat},
+    stat::{AccessMode, FdSet, FileDescriptor, FileMode, OpenFlags, Stat},
 };
 
 // TODO document the syscall ABI
@@ -325,3 +325,22 @@ pub fn sys_select(
         )
     })
 }
+
+#[inline(always)]
+pub fn sys_faccessat(
+    fd: Option<FileDescriptor>,
+    name: &str,
+    mode: AccessMode,
+    flags: u32,
+) -> Result<(), Errno> {
+    Errno::from_syscall_unit(unsafe {
+        syscall!(
+            abi::SYS_FACCESSAT,
+            argn!(FileDescriptor::into_i32(fd)),
+            argp!(name.as_ptr()),
+            argn!(name.len()),
+            argn!(mode.bits()),
+            argn!(flags)
+        )
+    })
+}

libsys/src/error.rs

@@ -15,6 +15,7 @@ pub enum Errno {
     NotADirectory,
     NotImplemented,
     OutOfMemory,
+    PermissionDenied,
     ReadOnly,
     TimedOut,
     TooManyDescriptors,

libsys/src/stat.rs

@@ -31,6 +31,15 @@ bitflags! {
     }
 }
 
+bitflags! {
+    pub struct AccessMode: u32 {
+        const R_OK = 1 << 0;
+        const W_OK = 1 << 1;
+        const X_OK = 1 << 2;
+        const F_OK = 1 << 3;
+    }
+}
+
 #[derive(Clone, Default)]
 pub struct FdSet {
     bits: [u64; 2]

libusr/src/sys/mod.rs

@@ -2,7 +2,8 @@ pub use libsys::signal::{Signal, SignalDestination};
 pub use libsys::proc::ExitCode;
 pub use libsys::termios;
 pub use libsys::calls::*;
-pub use libsys::stat::{self, FileDescriptor};
+pub use libsys::stat::{self, AccessMode, FileDescriptor};
+pub use libsys::error::Errno;
 
 use core::sync::atomic::{Ordering, AtomicBool};
 

user/Cargo.toml

@@ -13,6 +13,10 @@ path = "src/init/main.rs"
 name = "shell"
 path = "src/shell/main.rs"
 
+[[bin]]
+name = "fuzzy"
+path = "src/fuzzy/main.rs"
+
 [dependencies]
 libusr = { path = "../libusr" }
 lazy_static = { version = "*", features = ["spin_no_std"] }

user/src/fuzzy/main.rs

@@ -0,0 +1,10 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate libusr;
+
+#[no_mangle]
+fn main() -> i32 {
+    0
+}

user/src/shell/main.rs

@@ -3,34 +3,56 @@
 
 #[macro_use]
 extern crate libusr;
-#[macro_use]
-extern crate lazy_static;
+extern crate alloc;
 
-use libusr::thread;
+use alloc::borrow::ToOwned;
+use libusr::sys::{sys_faccessat, sys_exit, sys_execve, sys_waitpid, sys_fork, ExitCode, Errno, AccessMode};
 use libusr::io::{self, Read};
-use libusr::sys::{Signal, SignalDestination};
-use libusr::sync::Mutex;
 
-fn sleep(ns: u64) {
-    let mut rem = [0; 2];
-    libusr::sys::sys_ex_nanosleep(ns, &mut rem).unwrap();
+fn readline<'a, F: Read>(f: &mut F, bytes: &'a mut [u8]) -> Result<Option<&'a str>, io::Error> {
+    let size = f.read(bytes)?;
+    Ok(if size == 0 {
+        None
+    } else {
+        Some(core::str::from_utf8(&bytes[..size]).unwrap().trim_end_matches('\n'))
+    })
+}
+
+fn execvp(cmd: &str) -> ! {
+    sys_execve(&("/bin/".to_owned() + cmd));
+    sys_exit(ExitCode::from(-1));
+}
+
+fn execute(line: &str) -> Result<ExitCode, Errno> {
+    let mut words = line.split(' ');
+    let cmd = words.next().unwrap();
+
+    if let Some(pid) = sys_fork()? {
+        let mut status = 0;
+        sys_waitpid(pid, &mut status)?;
+        Ok(ExitCode::from(status))
+    } else {
+        execvp(cmd);
+    }
 }
 
 #[no_mangle]
 fn main() -> i32 {
-    let value = 1234;
-    let thread = thread::spawn(move || {
-        trace!("Closure is alive: {}", value);
-        sleep(2_000_000_000);
-        trace!("Closure will now exit");
+    let mut buf = [0; 256];
+    let mut stdin = io::stdin();
 
-        value - 100
-    });
-    sleep(1_000_000_000);
-
-    trace!("???");
-
-    trace!("Thread joined: {:?}", thread.join());
+    loop {
+        print!("> ");
+        let line = readline(&mut stdin, &mut buf).unwrap();
+        if line.is_none() {
+            break;
+        }
+        let line = line.unwrap().trim_start_matches(' ');
+        if line.is_empty() {
+            continue;
+        }
 
+        execute(line);
+    }
     0
 }