more things

.cargo/config.toml

@@ -1,2 +0,0 @@
-[target.x86_64-unknown-linux-gnu]
-rustflags = ["-Clink-arg=-nostartfiles", "-Clink-arg=-nostdlib"]

Cargo.lock

@@ -2,6 +2,12 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "autocfg"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -13,6 +19,26 @@ name = "libuwuc"
 version = "0.1.0"
 dependencies = [
  "cfg-if",
+ "linked_list_allocator",
+]
+
+[[package]]
+name = "linked_list_allocator"
+version = "0.10.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9afa463f5405ee81cdb9cc2baf37e08ec7e4c8209442b5d72c04cfb2cd6e6286"
+dependencies = [
+ "spinning_top",
+]
+
+[[package]]
+name = "lock_api"
+version = "0.4.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c1cc9717a20b1bb222f333e6a92fd32f7d8a18ddc5a3191a11af45dcbf4dcd16"
+dependencies = [
+ "autocfg",
+ "scopeguard",
 ]
 
 [[package]]
@@ -21,3 +47,18 @@ version = "0.1.0"
 dependencies = [
  "libuwuc",
 ]
+
+[[package]]
+name = "scopeguard"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
+
+[[package]]
+name = "spinning_top"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b9eb1a2f4c41445a3a0ff9abc5221c5fcd28e1f13cd7c0397706f9ac938ddb0"
+dependencies = [
+ "lock_api",
+]

example-user/Cargo.lock

@@ -2,6 +2,12 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "autocfg"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -21,6 +27,26 @@ name = "libuwuc"
 version = "0.1.0"
 dependencies = [
  "cfg-if",
+ "linked_list_allocator",
+]
+
+[[package]]
+name = "linked_list_allocator"
+version = "0.10.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9afa463f5405ee81cdb9cc2baf37e08ec7e4c8209442b5d72c04cfb2cd6e6286"
+dependencies = [
+ "spinning_top",
+]
+
+[[package]]
+name = "lock_api"
+version = "0.4.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c1cc9717a20b1bb222f333e6a92fd32f7d8a18ddc5a3191a11af45dcbf4dcd16"
+dependencies = [
+ "autocfg",
+ "scopeguard",
 ]
 
 [[package]]
@@ -29,3 +55,18 @@ version = "0.1.0"
 dependencies = [
  "libuwuc",
 ]
+
+[[package]]
+name = "scopeguard"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
+
+[[package]]
+name = "spinning_top"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b9eb1a2f4c41445a3a0ff9abc5221c5fcd28e1f13cd7c0397706f9ac938ddb0"
+dependencies = [
+ "lock_api",
+]

hello.c

@@ -1,5 +1,6 @@
 #include<stdio.h>
-
+#include<sys/mman.h>
 int main(int argc, char *argv[]) {
+    PROT_WRITE;
     puts("Hello, world!");
 }

libuwuc/Cargo.toml

@@ -7,3 +7,4 @@ edition = "2021"
 
 [dependencies]
 cfg-if = "1.0.0"
+linked_list_allocator = "0.10.5"

libuwuc/src/alloc.rs

@@ -0,0 +1,117 @@
+use core::{
+    alloc::{GlobalAlloc, Layout},
+    ffi::c_int,
+    sync::atomic::{AtomicUsize, Ordering},
+};
+
+use linked_list_allocator::LockedHeap;
+
+static ALLOCATOR: LockedHeap = LockedHeap::empty();
+
+const UNINIT: usize = 0;
+const INITIALIZING: usize = 1;
+const INIT: usize = 2;
+
+static INIT_STATE: AtomicUsize = AtomicUsize::new(0);
+
+fn init() {
+    let state =
+        INIT_STATE.compare_exchange(UNINIT, INITIALIZING, Ordering::Relaxed, Ordering::Acquire);
+
+    match state {
+        Ok(_) => unsafe {
+            const HEAP_SIZE: usize = 0x100000;
+            let map_anon = 0x20;
+            let prot_read = 1;
+            let prod_write = 2;
+
+            let start = mmap(
+                core::ptr::null(),
+                HEAP_SIZE,
+                prot_read | prod_write,
+                map_anon,
+                0,
+                0,
+            );
+            ALLOCATOR.lock().init(start, HEAP_SIZE);
+
+            INIT_STATE.store(INIT, Ordering::Release);
+        },
+        Err(INITIALIZING) => {
+            while INIT_STATE.load(Ordering::Acquire) != INIT {
+                core::hint::spin_loop();
+            }
+        }
+        Err(INIT) => {}
+        Err(_) => unreachable!(),
+    }
+}
+
+pub unsafe fn malloc_zeroed(size: usize, align: usize) -> *mut u8 {
+    /*
+    |start  |align  |offset |RETURN VALUE
+    */
+
+    init();
+    let (layout, offset) = Layout::array::<usize>(3)
+        .unwrap_unchecked()
+        .extend(Layout::from_size_align_unchecked(size, align))
+        .unwrap_unchecked();
+
+    let ptr = ALLOCATOR.alloc_zeroed(layout);
+    if ptr.is_null() {
+        return ptr;
+    }
+    ptr.cast::<[usize; 2]>()
+        .write([layout.size(), layout.align()]);
+
+    let ret_ptr = ptr.add(offset);
+    ret_ptr.cast::<usize>().sub(1).write(offset);
+
+    ret_ptr
+}
+
+pub unsafe fn free(ptr: *mut u8) {
+    init();
+    let offset = ptr.cast::<usize>().sub(1).read();
+    let start = ptr.sub(offset);
+    let [size, align] = start.cast::<[usize; 2]>().read();
+    let layout = Layout::from_size_align_unchecked(size, align);
+    ALLOCATOR.dealloc(start, layout);
+}
+
+pub unsafe fn mmap(
+    addr: *const u8,
+    size: usize,
+    prot: c_int,
+    flags: c_int,
+    fd: c_int,
+    offset: u64,
+) -> *mut u8 {
+    #[cfg(miri)]
+    {
+        extern crate std;
+        return std::alloc::System.alloc_zeroed(Layout::from_size_align_unchecked(size, 4096));
+    }
+    crate::sys::syscall::syscall!(
+        crate::sys::syscall::SYS_MMAP,
+        addr,
+        size,
+        prot,
+        flags,
+        fd,
+        offset
+    ) as *mut u8
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn malloc_free() {
+        unsafe {
+            let x = super::malloc_zeroed(10, 8);
+            x.cast::<usize>().write(10);
+            super::free(x);
+        }
+    }
+}

libuwuc/src/env.rs

@@ -47,6 +47,7 @@ impl Iterator for EnvP {
     }
 }
 
+#[allow(unused)]
 pub(crate) fn debug_env() {
     println!("start vars");
     global::get().for_each(|s| {

libuwuc/src/io/mod.rs

@@ -29,7 +29,7 @@ macro_rules! println {
 pub use println;
 
 pub unsafe fn write_all(fd: i32, mut buf: &[u8]) -> Result<(), i64> {
-    while buf.len() > 0 {
+    while !buf.is_empty() {
         let result = syscall::syscall!(syscall::SYS_WRITE, fd, buf.as_ptr(), buf.len()) as i64;
         if result < 0 {
             return Err(result);

libuwuc/src/lib.rs

@@ -1,12 +1,15 @@
 #![no_std]
 #![warn(unreachable_pub)]
 
+#![allow(clippy::missing_safety_doc)]
+
 #[cfg(test)]
 extern crate std;
 
-pub mod mem;
+pub mod alloc;
 pub mod env;
 pub mod io;
+pub mod mem;
 pub mod start;
 mod stubs;
 mod sys;

libuwuc/src/start.rs

@@ -27,3 +27,12 @@ pub fn exit(code: u64) -> ! {
         core::hint::unreachable_unchecked()
     }
 }
+
+pub fn abort() -> ! {
+    // FIXME: we actually need to do signal shenanigans
+    unsafe {
+        crate::sys::syscall::syscall!(crate::sys::syscall::SYS_EXIT, 1);
+        crate::sys::helpers::trap!();
+        core::hint::unreachable_unchecked()
+    }
+}

libuwuc/src/sys/x86_64/syscall/mod.rs

@@ -48,6 +48,48 @@ macro_rules! syscall {
         );
         out
     }};
+    ($number:expr, $arg1:expr, $arg2:expr, $arg3:expr, $arg4:expr) => {{
+        let out: u64;
+        ::core::arch::asm!(
+            "syscall",
+            in("rax") $number,
+            in("rdi") $arg1,
+            in("rsi") $arg2,
+            in("rdx") $arg3,
+            in("r10") $arg4,
+            lateout("rax") out,
+        );
+        out
+    }};
+    ($number:expr, $arg1:expr, $arg2:expr, $arg3:expr, $arg4:expr, $arg5:expr) => {{
+        let out: u64;
+        ::core::arch::asm!(
+            "syscall",
+            in("rax") $number,
+            in("rdi") $arg1,
+            in("rsi") $arg2,
+            in("rdx") $arg3,
+            in("r10") $arg4,
+            in("r8") $arg5,
+            lateout("rax") out,
+        );
+        out
+    }};
+    ($number:expr, $arg1:expr, $arg2:expr, $arg3:expr, $arg4:expr, $arg5:expr, $arg6:expr) => {{
+        let out: u64;
+        ::core::arch::asm!(
+            "syscall",
+            in("rax") $number,
+            in("rdi") $arg1,
+            in("rsi") $arg2,
+            in("rdx") $arg3,
+            in("r10") $arg4,
+            in("r8") $arg5,
+            in("r9") $arg6,
+            lateout("rax") out,
+        );
+        out
+    }};
 }
 
 pub use syscall;

libuwuc/src/utils/mod.rs

@@ -83,7 +83,7 @@ impl From<SharedThinCstr> for &CStr {
 
 impl PartialEq for SharedThinCstr {
     fn eq(&self, other: &Self) -> bool {
-        self.into_iter().eq(other.into_iter())
+        self.into_iter().eq(*other)
     }
 }
 

rawc/build.rs

@@ -0,0 +1,4 @@
+fn main() {
+    println!("cargo:rustc-link-arg=-nostartfiles");
+    println!("cargo:rustc-link-arg=-nostdlib");
+}

rawc/src/lib.rs

@@ -1,11 +1,15 @@
 #![no_std]
 #![feature(panic_info_message)]
+#![deny(clippy::no_mangle_with_rust_abi)]
 
+mod rt;
 mod stdio;
+mod stdlib;
 mod string;
 
 // libcore seems to require this symbol, even though it's unused.
 #[no_mangle]
+#[allow(clippy::no_mangle_with_rust_abi)]
 fn rust_eh_personality() {
     unsafe {
         libuwuc::trap!();

rawc/src/rt.rs

@@ -0,0 +1,7 @@
+#[no_mangle]
+pub extern "C" fn __stack_chk_fail() -> ! {
+    unsafe {
+        let _ = libuwuc::io::write_all(libuwuc::io::STDERR, b"error: stack overflow");
+        libuwuc::start::abort();
+    }
+}

rawc/src/stdlib.rs

@@ -0,0 +1,14 @@
+#[no_mangle]
+pub unsafe extern "C" fn malloc(size: usize) -> *mut u8 {
+    libuwuc::alloc::malloc_zeroed(size, 16)
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn free(ptr: *mut u8) {
+    libuwuc::alloc::free(ptr)
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn exit(code: i32) -> ! {
+    libuwuc::start::exit(code as i64 as _)
+}

rawc/src/string.rs

@@ -9,13 +9,13 @@ pub unsafe extern "C" fn memcpy(dest: *mut u8, src: *const u8, size: usize) -> *
 }
 
 #[no_mangle]
-pub unsafe fn memcmp(s1: *const u8, s2: *const u8, size: usize) -> i32 {
+pub unsafe extern "C" fn memcmp(s1: *const u8, s2: *const u8, size: usize) -> i32 {
     libuwuc::mem::memcmp(s1, s2, size)
 }
 
 
 #[no_mangle]
-pub unsafe fn bcmp(s1: *const u8, s2: *const u8, size: usize) -> i32 {
+pub unsafe extern "C" fn bcmp(s1: *const u8, s2: *const u8, size: usize) -> i32 {
     libuwuc::mem::memcmp(s1, s2, size)
 }
 

test.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-cargo run --manifest-path example-user/Cargo.toml --target x86_64-unknown-linux-gnu
+cargo run --manifest-path example-user/Cargo.toml