Don't die after panics

Let's leave the chance to attach a debugger.

Author: sysheap

.cargo/config.toml

@@ -7,6 +7,7 @@ target = "riscv64gc-unknown-none-elf"
 [target.riscv64gc-unknown-none-elf]
 runner = """
 qemu-system-riscv64 \
+    -s \
     -machine virt \
     -cpu rv64 \
     -smp 1 \

justfile

@@ -28,6 +28,9 @@ test:
 miri: build-cargo
     MIRIFLAGS="-Zmiri-permissive-provenance -Zmiri-env-forward=RUST_BACKTRACE" RUST_BACKTRACE=1 cargo miri test --target riscv64gc-unknown-linux-gnu
 
+attach:
+    gdb-multiarch $(pwd)/target/riscv64gc-unknown-none-elf/release/kernel -ex "target remote :1234"
+
 debug: build
     tmux new-session -d '{{debugReleaseCommand}}' \; split-window -v 'gdb-multiarch $(pwd)/target/riscv64gc-unknown-none-elf/release/kernel -ex "target remote :1234"' \; attach
 

kernel/src/cpu.rs

@@ -49,10 +49,11 @@ pub fn memory_fence() {
     }
 }
 
-pub fn disable_gloabl_interrupts() {
+pub unsafe fn disable_global_interrupts() {
     unsafe {
         asm!(
-            "csrc sstatus, {}",
+            "csrc sstatus, {}", // Disable global interrupt flag
+            "csrw sie, x0", // Clear any local enabled interrupts otherwise wfi just goes to the current pending interrupt
         in(reg) 0b10);
     }
 }

kernel/src/panic.rs

@@ -1,15 +1,18 @@
 #![cfg_attr(miri, allow(unused_imports))]
-use crate::{io::uart::QEMU_UART, println, test::qemu_exit};
+use crate::{
+    io::uart::QEMU_UART, memory::page_tables::KERNEL_PAGE_TABLES, println,
+    test::qemu_exit::wait_for_the_end,
+};
 use core::{panic::PanicInfo, sync::atomic::AtomicU8};
 
 static PANIC_COUNTER: AtomicU8 = AtomicU8::new(0);
 
 #[cfg(not(miri))]
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
-    use crate::memory::page_tables::KERNEL_PAGE_TABLES;
-
-    crate::cpu::disable_gloabl_interrupts();
+    unsafe {
+        crate::cpu::disable_global_interrupts();
+    }
 
     // SAFTEY: The worst what happen is scrambled output
     // Disable the stdout mutex in case it was locked before
@@ -30,14 +33,16 @@ fn panic(info: &PanicInfo) -> ! {
     crate::debugging::backtrace::print();
     crate::debugging::dump_current_state();
 
-    qemu_exit::exit_failure(1);
+    println!("Time to attach gdb ;) use 'just attach'");
+    wait_for_the_end();
 }
 
 fn abort_if_double_panic() {
     let current = PANIC_COUNTER.fetch_add(1, core::sync::atomic::Ordering::SeqCst);
 
     if current >= 1 {
         println!("Panic in panic! ABORTING!");
-        qemu_exit::exit_failure(1);
+        println!("Time to attach gdb ;) use 'just attach'");
+        wait_for_the_end();
     }
 }

kernel/src/test/qemu_exit.rs

@@ -27,9 +27,11 @@ pub fn exit_reset() -> ! {
     wait_for_the_end();
 }
 
-fn wait_for_the_end() -> ! {
-    cpu::disable_gloabl_interrupts();
-    cpu::wait_for_interrupt();
-    #[allow(clippy::empty_loop)]
-    loop {}
+pub fn wait_for_the_end() -> ! {
+    unsafe {
+        cpu::disable_global_interrupts();
+    }
+    loop {
+        cpu::wait_for_interrupt();
+    }
 }