From be01fbd943e8755a8c6fa4d7a3897d08120af9fe Mon Sep 17 00:00:00 2001 From: pca006132 Date: Mon, 18 Jan 2021 16:43:49 +0800 Subject: [PATCH] runtime/irq: use assembly for naked IRQ handler and solves the bug introduced due to stack unwinding... --- src/runtime/src/irq.rs | 24 +++++++++++++++++++++++- src/runtime/src/main.rs | 1 + 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/src/runtime/src/irq.rs b/src/runtime/src/irq.rs index 84b6afea..0b9df77b 100644 --- a/src/runtime/src/irq.rs +++ b/src/runtime/src/irq.rs @@ -18,14 +18,36 @@ static CORE1_RESTART: AtomicBool = AtomicBool::new(false); #[no_mangle] #[naked] pub unsafe extern "C" fn IRQ() { + asm!( + // setup SP, depending on CPU 0 or 1 + "mrc p15, #0, r0, c0, c0, #5", + "movw r1, :lower16:__stack0_start", + "movt r1, :upper16:__stack0_start", + "tst r0, #3", + "movwne r1, :lower16:__stack1_start", + "movtne r1, :upper16:__stack1_start", + "mov sp, r1", + "bl __IRQ", + options(noreturn) + ); +} + +#[no_mangle] +pub unsafe extern "C" fn __IRQ() { if MPIDR.read().cpu_id() == 1 { let mpcore = mpcore::RegisterBlock::mpcore(); let mut gic = gic::InterruptController::gic(mpcore); let id = gic.get_interrupt_id(); if id.0 == 0 { gic.end_interrupt(id); + // save the SP and set it back after exiting IRQ + // exception unwinding expect to unwind from this function, as this is not the entrance + // function, maybe to IRQ which cannot further unwind... + // if we set the SP to __stack1_start, interesting exceptions would be triggered when + // we try to unwind the stack... + let v = SP.read(); asm::exit_irq(); - SP.write(&mut __stack1_start as *mut _ as u32); + SP.write(v); asm::enable_irq(); CORE1_RESTART.store(false, Ordering::Relaxed); notify_spin_lock(); diff --git a/src/runtime/src/main.rs b/src/runtime/src/main.rs index f8b7c6a7..5fa0f4af 100644 --- a/src/runtime/src/main.rs +++ b/src/runtime/src/main.rs @@ -7,6 +7,7 @@ #![feature(const_btree_new)] #![feature(const_in_array_repeat_expressions)] #![feature(naked_functions)] +#![feature(asm)] extern crate alloc;