Merge pull request #2095 from hermit-os/fn-as-usize

fix: avoid casting functions to usize if possible

Author: mkroening

src/arch/aarch64/kernel/mod.rs

@@ -137,7 +137,7 @@ pub fn boot_next_processor() {
 		if cpu_online == 0 {
 			use aarch64_cpu::registers::{Readable, TTBR0_EL1};
 
-			let virt_start = VirtAddr::from(smp_start as *const () as usize);
+			let virt_start = VirtAddr::from_ptr(smp_start as *const ());
 			let phys_start = virtual_to_physical(virt_start).unwrap();
 			assert!(virt_start.as_u64() == phys_start.as_u64());
 

src/arch/x86_64/kernel/apic.rs

@@ -750,6 +750,7 @@ pub fn init_next_processor_variables() {
 pub fn boot_application_processors() {
 	use core::hint;
 
+	use hermit_entry::boot_info::RawBootInfo;
 	use x86_64::structures::paging::Translate;
 
 	use super::start;
@@ -800,10 +801,9 @@ pub fn boot_application_processors() {
 			"Set entry point for application processor to {:p}",
 			start::_start as *const ()
 		);
-		ptr::write_unaligned(
-			(SMP_BOOT_CODE_ADDRESS + SMP_BOOT_CODE_OFFSET_ENTRY).as_mut_ptr(),
-			start::_start as *const () as usize,
-		);
+		(SMP_BOOT_CODE_ADDRESS + SMP_BOOT_CODE_OFFSET_ENTRY)
+			.as_mut_ptr::<unsafe extern "C" fn(Option<&'static RawBootInfo>, cpu_id: u32) -> !>()
+			.write_unaligned(start::_start);
 	}
 
 	// Now wake up each application processor.

src/arch/x86_64/kernel/processor.rs

@@ -917,8 +917,8 @@ pub fn configure() {
 		let cs_syscall = SegmentSelector::new(1, PrivilegeLevel::Ring0);
 		let ss_syscall = SegmentSelector::new(2, PrivilegeLevel::Ring0);
 		Star::write(cs_sysret, ss_sysret, cs_syscall, ss_syscall).unwrap();
-		let syscall_handler_addr = syscall::syscall_handler as *const () as usize;
-		let syscall_handler_addr = VirtAddr::new(syscall_handler_addr.try_into().unwrap());
+		let syscall_handler_addr = syscall::syscall_handler as *const ();
+		let syscall_handler_addr = VirtAddr::from_ptr(syscall_handler_addr);
 		LStar::write(syscall_handler_addr);
 		SFMask::write(RFlags::INTERRUPT_FLAG); // clear IF flag during system call
 	}