whoops i ran out of stack space

src/interrupts.rs

@@ -125,7 +125,7 @@ unsafe extern "x86-interrupt" fn timer_naked() {
     }
 }
 
-const FREQUENCY_DIVIDER: u8 = 15;
+const FREQUENCY_DIVIDER: u8 = 5;
 
 static mut TIMER_COUNT: u8 = 0;
 

src/main.rs

@@ -5,9 +5,9 @@
 extern crate alloc;
 
 use bootloader::{entry_point, BootInfo};
-use core::{panic::PanicInfo, arch::asm, hint::black_box};
+use core::{panic::PanicInfo, hint::black_box};
 use os::{println, proc::{PROCESSES, ProcessControlBlock, Registers}};
-use x86_64::{instructions::{hlt, interrupts::{without_interrupts, self}}, structures::idt::InterruptStackFrameValue, registers::{segmentation::{CS, Segment, SS}, self}, VirtAddr};
+use x86_64::{instructions::{hlt, interrupts::{without_interrupts}}, structures::idt::InterruptStackFrameValue, registers::{segmentation::{CS, Segment, SS}, self}, VirtAddr};
 
 entry_point!(main);
 fn main(bootinfo: &'static BootInfo) -> ! {
@@ -22,7 +22,7 @@ fn main(bootinfo: &'static BootInfo) -> ! {
     without_interrupts(|| {
         let mut procs = PROCESSES.lock();
 
-        static mut PROC_1_STACK: [u8; 1024] = [0; 1024];
+        static mut PROC_1_STACK: [u8; 4096] = [0; 4096];
 
         let stack_frame = InterruptStackFrameValue {
             instruction_pointer: VirtAddr::new(proc1 as u64),
@@ -36,7 +36,7 @@ fn main(bootinfo: &'static BootInfo) -> ! {
 
         procs[1].write(ProcessControlBlock { stack_frame, registers });
 
-        static mut PROC_2_STACK: [u8; 1024] = [0; 1024];
+        static mut PROC_2_STACK: [u8; 4096] = [0; 4096];
 
         let stack_frame = InterruptStackFrameValue {
             instruction_pointer: VirtAddr::new(proc2 as u64),
@@ -54,15 +54,15 @@ fn main(bootinfo: &'static BootInfo) -> ! {
         procs[0].prev = 2;
 
         procs[1].next = 2;
-        procs[1].prev = 2;
+        procs[1].prev = 0;
 
-        procs[2].next = 1;
+        procs[2].next = 0;
         procs[2].prev = 1;
     });
 
     loop {
         println!("Hi from main proc!");
-        for i in 0..500000 { black_box(i); }
+        for i in 0..200000 { black_box(i); }
     }
 
     loop {
@@ -74,14 +74,14 @@ fn main(bootinfo: &'static BootInfo) -> ! {
 extern "C" fn proc1() -> ! {
     loop {
         println!("Hi from proc 1!");
-        for i in 0..500000 { black_box(i); }
+        for i in 0..200000 { black_box(i); }
     }
 }
 
 extern "C" fn proc2() -> ! {
     loop {
         println!("Hi from proc 2, foo bar baz!");
-        for i in 0..500000 { black_box(i); }
+        for i in 0..200000 { black_box(i); }
     }
 }
 

src/proc.rs

@@ -1,10 +1,10 @@
-use core::{fmt::Debug, mem, hint::black_box};
+use core::{fmt::Debug, mem};
 
 use alloc::boxed::Box;
 use spin::Mutex;
 use x86_64::{VirtAddr, structures::{paging::{Page, PageTableFlags}, idt::InterruptStackFrameValue}};
 
-use crate::{sync::SyncLazy, mem::map_next, lazy_static, assert_canonical, println};
+use crate::{sync::SyncLazy, mem::map_next, lazy_static, assert_canonical};
 
 #[derive(Clone, Copy, Debug)]
 pub struct ProcessControlBlock {
@@ -66,19 +66,13 @@ pub struct ProcListElement {
 
 impl ProcListElement {
     pub fn write(&mut self, pcb: ProcessControlBlock) {
-        println!("write");
         match self.pcb.as_deref_mut() {
             None => {
                 let addr = Box::leak(Box::new(pcb));
-                // with this println, it tries to execute 0x0. without it, it (sometimes) tries to execute PROCESS_LIST_ADDR.
-                // whatever the case, it happens after 1 println in `fn timer`, before this code is even hit.
-                // if the line up above ^^^ is inlined, it faults after 2 printlns instead. what in the actual fuck
-                // println!("addr: {:x}", addr as *mut _ as usize);
                 self.pcb.replace(addr);
             }
             Some(v) => { *v = pcb; }
         }
-        // println!("end write");
     }
 }
 
@@ -96,37 +90,23 @@ static CURRENT_PROCESS: Mutex<u64> = Mutex::new(0);
 
 // here i make the assumption that the privilege level is *somewhere* in `InterruptStackFrame`
 pub fn timer(stack_frame: &mut InterruptStackFrameValue, registers: &mut Registers) {
-    println!("Hello there from timer interrupt");
-
     let mut curr_pid = CURRENT_PROCESS.lock();
     let mut procs = PROCESSES.lock();
 
-    println!("Hello there from timer interrupt 2");
-
     // first, save the stack and registers values in the pcb for this pid
     procs[*curr_pid as usize].write(ProcessControlBlock {
         stack_frame: *stack_frame,
         registers: *registers,
     });
 
-    println!("Hello there from timer interrupt 3");
-
     // then, choose the next pid
     let next_pid = procs[*curr_pid as usize].next as u64;
     *curr_pid = next_pid;
     let next = procs[next_pid as usize].pcb.as_deref().unwrap();
 
-    println!("Hello there from timer interrupt 4");
-
     // last, load the stack and registers values from the new pid
     *stack_frame = next.stack_frame;
     *registers = next.registers;
-
-    // println!("Next pid: {}", *curr_pid);
-    // println!("Next stack_frame: {:?}", stack_frame);
-    // println!("Next registers: {:?}", registers);
-
-    for i in 0..5000000 { black_box(i); }
 }
 
 pub fn init() {