redox-rt/src/sync.rs

+// TODO: Share code for simple futex-based mutex between relibc's Mutex<()> and this.
+
+use core::{
+    cell::UnsafeCell,
+    ops::{Deref, DerefMut},
+    sync::atomic::{AtomicU32, Ordering},
+};
+
+pub struct Mutex<T> {
+    pub lockword: AtomicU32,
+    pub inner: UnsafeCell<T>,
+}
+
+const UNLOCKED: u32 = 0;
+const LOCKED: u32 = 1;
+const WAITING: u32 = 2;
+
+unsafe impl<T: Send> Send for Mutex<T> {}
+unsafe impl<T: Send> Sync for Mutex<T> {}
+
+impl<T> Mutex<T> {
+    pub const fn new(t: T) -> Self {
+        Self {
+            lockword: AtomicU32::new(0),
+            inner: UnsafeCell::new(t),
+        }
+    }
+    pub fn lock(&self) -> MutexGuard<'_, T> {
+        while self
+            .lockword
+            .compare_exchange(UNLOCKED, LOCKED, Ordering::Acquire, Ordering::Relaxed)
+            .is_err()
+        {
+            core::hint::spin_loop();
+        }
+        MutexGuard { lock: self }
+    }
+}
+pub struct MutexGuard<'l, T> {
+    lock: &'l Mutex<T>,
+}
+impl<T> Deref for MutexGuard<'_, T> {
+    type Target = T;
+
+    fn deref(&self) -> &T {
+        unsafe { &*self.lock.inner.get() }
+    }
+}
+impl<T> DerefMut for MutexGuard<'_, T> {
+    fn deref_mut(&mut self) -> &mut T {
+        unsafe { &mut *self.lock.inner.get() }
+    }
+}
+impl<T> Drop for MutexGuard<'_, T> {
+    fn drop(&mut self) {
+        self.lock.lockword.store(UNLOCKED, Ordering::Release);
+    }
+}

redoxer.sh

@@ -12,6 +12,7 @@ then
     redoxer toolchain
 fi
 
+export CARGOFLAGS=""
 export CARGO_TEST="redoxer"
-export TEST_RUNNER="redoxer exec --folder . -- sh --"
+export TEST_RUNNER="redoxer exec --folder . --"
 redoxer env make "$@"

rust-toolchain

-nightly-2020-07-27

rust-toolchain.toml

+[toolchain]
+channel = "nightly-2025-01-12"
+components = ["rust-src"]

src/c/fcntl.c

-#include <stdarg.h>
-#include <sys/types_internal.h>
-
-// TODO: Can be implemented in rust when cbindgen supports "..." syntax
-
-int sys_open(const char* filename, int flags, mode_t mode);
-
-int open(const char* filename, int flags, ...) {
-    mode_t mode = 0;
-    va_list ap;
-    va_start(ap, flags);
-    mode = va_arg(ap, mode_t);
-    va_end(ap);
-    return sys_open(filename, flags, mode);
-}
-
-int sys_fcntl(int fildes, int cmd, int args);
-
-int fcntl(int fildes, int cmd, ...) {
-    int args = 0;
-    va_list ap;
-    va_start(ap, cmd);
-    args = va_arg(ap, int);
-    va_end(ap);
-    return sys_fcntl(fildes, cmd, args);
-}

src/c/stack_chk.c

-#include <stdint.h>
-
-void abort();
-
-uintptr_t __stack_chk_guard = 0xd048c37519fcadfe;
-
-__attribute__((noreturn))
-void __stack_chk_fail(void) {
-	abort();
-}