Merge pull request #2094 from hermit-os/arch-scheduler-fn-ptr

fix(arch/scheduler): don't cast task_start to pointer

Author: mkroening

src/arch/aarch64/kernel/scheduler.rs

@@ -25,7 +25,7 @@ pub(crate) struct State {
 	/// stack selector
 	pub spsel: u64,
 	/// Exception Link Register
-	pub elr_el1: u64,
+	pub elr_el1: extern "C" fn(extern "C" fn(usize), usize) -> !,
 	/// Program Status Register
 	pub spsr_el1: u64,
 	/// User-level stack
@@ -317,7 +317,7 @@ impl TaskFrame for Task {
 			 * The elr_el1 needs to hold the address of the
 			 * first function to be called when returning from exception handler.
 			 */
-			(*state).elr_el1 = task_start as *const () as usize as u64;
+			(*state).elr_el1 = task_start;
 			(*state).x0 = func as usize as u64; // use second argument to transfer the entry point
 			(*state).x1 = arg as u64;
 			(*state).spsel = 1;

src/arch/riscv64/kernel/scheduler.rs

@@ -15,7 +15,7 @@ use crate::{DEFAULT_STACK_SIZE, KERNEL_STACK_SIZE};
 #[derive(Clone, Copy, Debug)]
 pub struct State {
 	/// return address register
-	ra: usize,
+	ra: unsafe extern "C" fn(extern "C" fn(usize), usize, u64),
 	/// stack pointer register
 	sp: usize,
 	/// global pointer register
@@ -331,7 +331,7 @@ impl TaskFrame for Task {
 			if let Some(tls) = &self.tls {
 				(*state).tp = tls.thread_ptr() as usize;
 			}
-			(*state).ra = task_start as *const () as usize;
+			(*state).ra = task_start;
 			(*state).a0 = func as usize;
 			(*state).a1 = arg;
 

src/arch/x86_64/kernel/scheduler.rs

@@ -59,7 +59,7 @@ struct State {
 	/// status flags
 	rflags: u64,
 	/// instruction pointer
-	rip: u64,
+	rip: extern "C" fn(extern "C" fn(usize), usize, u64) -> !,
 }
 
 pub struct BootStack {
@@ -303,7 +303,7 @@ impl TaskFrame for Task {
 			if let Some(tls) = &self.tls {
 				(*state).fs = tls.thread_ptr().addr() as u64;
 			}
-			(*state).rip = task_start as *const () as usize as u64;
+			(*state).rip = task_start;
 			(*state).rdi = func as usize as u64;
 			(*state).rsi = arg as u64;