Add signal facilities

src/process.rs

@@ -1,6 +1,3 @@
 //! Process management data types
 
-pub use abi::process::{SpawnOption, SpawnOptions};
-
-/// Status code returned when a process terminates
-pub type ExitStatus = i32;
+pub use abi::process::{ExitCode, Signal, SignalEntryData, SpawnOption, SpawnOptions};

src/sys.rs

@@ -7,14 +7,14 @@ use abi::{
         DirectoryEntry, FileAttr, FileMode, MountOptions, OpenOptions, RawFd, SeekFrom,
         UnmountOptions,
     },
-    process::SpawnOptions,
+    process::{ExitCode, Signal, SpawnOptions},
     syscall::SyscallFunction,
 };
 
 macro_rules! syscall {
     ($num:expr) => {{
         let mut res: usize;
-        core::arch::asm!("svc #0", lateout("x0") res, in("x8") $num.repr());
+        core::arch::asm!("svc #0", lateout("x0") res, in("x8") usize::from($num));
         res
     }};
     ($num:expr, $a0:expr) => {{
@@ -123,7 +123,8 @@ pub unsafe fn nanosleep(duration: Duration) {
 /// # Safety
 ///
 /// Unsafe: direct system call.
-pub unsafe fn exit(code: i32) -> ! {
+pub unsafe fn exit(code: ExitCode) -> ! {
+    let code = i32::from(code);
     syscall!(SyscallFunction::Exit, argn!(code));
     panic!();
 }
@@ -318,16 +319,62 @@ pub unsafe fn seek(fd: RawFd, pos: SeekFrom) -> Result<u64, Error> {
     u64::from_syscall_result(syscall!(SyscallFunction::Seek, argn!(fd.0), argn!(u64::from(pos))))
 }
 
+/// System call: create a new process.
 ///
+/// # Safety
+///
+/// Unsafe: direct system call.
 pub unsafe fn spawn(options: &SpawnOptions<'_>) -> Result<u32, Error> {
     u32::from_syscall_result(syscall!(SyscallFunction::Spawn, argp!(options as *const _)))
 }
 
+/// System call: wait for a process to finish
 ///
-pub unsafe fn wait_process(pid: u32, status: &mut i32) -> Result<(), Error> {
+/// # Safety
+///
+/// Unsafe: direct system call.
+pub unsafe fn wait_process(pid: u32, status: &mut ExitCode) -> Result<(), Error> {
     <()>::from_syscall_result(syscall!(
         SyscallFunction::WaitProcess,
         argn!(pid),
         argp!(status as *mut _)
     ))
 }
+
+/// System call: send a signal to the target process.
+///
+/// # Safety
+///
+/// Unsafe: direct system call.
+pub unsafe fn send_signal(pid: u32, signal: Signal) -> Result<(), Error> {
+    let signal = u32::from(signal);
+    <()>::from_syscall_result(syscall!(SyscallFunction::SendSignal, argn!(pid), argn!(signal)))
+}
+
+/// System call: set the process signal handler information.
+///
+/// # Safety
+///
+/// Unsafe: direct system call.
+pub unsafe fn set_signal_entry(entry: usize, sp: usize) {
+    syscall!(SyscallFunction::SetSignalEntry, argn!(entry), argn!(sp));
+}
+
+/// System call: return from a signal handler.
+///
+/// # Safety
+///
+/// Unsafe: direct system call.
+pub unsafe fn exit_signal() -> ! {
+    syscall!(SyscallFunction::ExitSignal);
+    panic!("Cannot return here");
+}
+
+/// System call: get the caller process ID.
+///
+/// # Safety
+///
+/// Unsafe: direct system call.
+pub unsafe fn get_pid() -> u32 {
+    syscall!(SyscallFunction::GetPid) as _
+}