From 0ed9f0331704d2ffdd717a8baecfb93305bcf851 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Wed, 24 Aug 2022 12:29:48 -0600
Subject: [PATCH] Use push/pop scratch for aarch64 signal handler
---
src/context/arch/aarch64.rs | 140 +++++++-----------------------------
1 file changed, 26 insertions(+), 114 deletions(-)
diff --git a/src/context/arch/aarch64.rs b/src/context/arch/aarch64.rs
index 6233cfc2..205841ba 100644
--- a/src/context/arch/aarch64.rs
+++ b/src/context/arch/aarch64.rs
@@ -4,6 +4,8 @@ use core::mem;
use core::sync::atomic::{AtomicBool, Ordering};
use spin::Once;
+use crate::{push_scratch, pop_scratch};
+use crate::interrupt::handler::ScratchRegisters;
use crate::device::cpu::registers::{control_regs, tlb};
use crate::paging::{RmmA, RmmArch, TableKind};
use crate::syscall::FloatRegisters;
@@ -118,10 +120,10 @@ impl Context {
}
pub unsafe fn signal_stack(&mut self, handler: extern fn(usize), sig: u8) {
- self.push_stack(sig as usize);
- self.push_stack(handler as usize);
let lr = self.lr.clone();
self.push_stack(lr);
+ self.push_stack(sig as usize);
+ self.push_stack(handler as usize);
self.set_lr(signal_handler_wrapper as usize);
}
@@ -408,127 +410,37 @@ unsafe extern "C" fn switch_to_inner(prev: &mut Context, next: &mut Context) {
#[allow(dead_code)]
#[repr(packed)]
pub struct SignalHandlerStack {
- x28: usize, /* Callee saved Register */
- x27: usize, /* Callee saved Register */
- x26: usize, /* Callee saved Register */
- x25: usize, /* Callee saved Register */
- x24: usize, /* Callee saved Register */
- x23: usize, /* Callee saved Register */
- x22: usize, /* Callee saved Register */
- x21: usize, /* Callee saved Register */
- x20: usize, /* Callee saved Register */
- x19: usize, /* Callee saved Register */
- x18: usize,
- x17: usize,
- x16: usize,
- x15: usize, /* Temporary Register */
- x14: usize, /* Temporary Register */
- x13: usize, /* Temporary Register */
- x12: usize, /* Temporary Register */
- x11: usize, /* Temporary Register */
- x10: usize, /* Temporary Register */
- x9: usize, /* Temporary Register */
- x8: usize, /* Indirect location Register */
- x7: usize,
- x6: usize,
- x5: usize,
- x4: usize,
- x3: usize,
- x2: usize,
- x1: usize,
- x0: usize,
- lr: usize,
+ scratch: ScratchRegisters,
+ padding: usize,
handler: extern fn(usize),
sig: usize,
+ lr: usize,
}
#[naked]
unsafe extern fn signal_handler_wrapper() {
- core::arch::asm!(
- "
- udf #0
- ",
- options(noreturn)
- );
- /*TODO: convert to asm!
#[inline(never)]
- unsafe fn inner(stack: &SignalHandlerStack) {
+ unsafe extern "C" fn inner(stack: &SignalHandlerStack) {
(stack.handler)(stack.sig);
}
// Push scratch registers
- llvm_asm!("str x0, [sp, #-8]!
- str x1, [sp, #-8]!
- str x2, [sp, #-8]!
- str x3, [sp, #-8]!
- str x4, [sp, #-8]!
- str x5, [sp, #-8]!
- str x6, [sp, #-8]!
- str x7, [sp, #-8]!
- str x8, [sp, #-8]!
- str x9, [sp, #-8]!
- str x10, [sp, #-8]!
- str x11, [sp, #-8]!
- str x12, [sp, #-8]!
- str x13, [sp, #-8]!
- str x14, [sp, #-8]!
- str x15, [sp, #-8]!
- str x16, [sp, #-8]!
- str x17, [sp, #-8]!
- str x18, [sp, #-8]!
- str x19, [sp, #-8]!
- str x20, [sp, #-8]!
- str x21, [sp, #-8]!
- str x22, [sp, #-8]!
- str x23, [sp, #-8]!
- str x24, [sp, #-8]!
- str x25, [sp, #-8]!
- str x26, [sp, #-8]!
- str x27, [sp, #-8]!
- str x28, [sp, #-8]!"
- : : : : "volatile");
-
- // Get reference to stack variables
- let sp: usize;
- llvm_asm!("" : "={sp}"(sp) : : : "volatile");
-
- let ptr = sp as *const SignalHandlerStack;
- let final_lr = (*ptr).lr;
-
- // Call inner rust function
- inner(&*(sp as *const SignalHandlerStack));
-
- // Pop scratch registers, error code, and return
- llvm_asm!("ldr x28, [sp], #8
- ldr x27, [sp], #8
- ldr x26, [sp], #8
- ldr x25, [sp], #8
- ldr x24, [sp], #8
- ldr x23, [sp], #8
- ldr x22, [sp], #8
- ldr x21, [sp], #8
- ldr x20, [sp], #8
- ldr x19, [sp], #8
- ldr x18, [sp], #8
- ldr x17, [sp], #8
- ldr x16, [sp], #8
- ldr x15, [sp], #8
- ldr x14, [sp], #8
- ldr x13, [sp], #8
- ldr x12, [sp], #8
- ldr x11, [sp], #8
- ldr x10, [sp], #8
- ldr x9, [sp], #8
- ldr x8, [sp], #8
- ldr x7, [sp], #8
- ldr x6, [sp], #8
- ldr x5, [sp], #8
- ldr x4, [sp], #8
- ldr x3, [sp], #8
- ldr x2, [sp], #8
- ldr x1, [sp], #8"
- : : : : "volatile");
-
- llvm_asm!("mov x30, $0" : : "r"(final_lr) : "memory" : "volatile");
- */
+ core::arch::asm!(
+ concat!(
+ "sub sp, sp, 8",
+ push_scratch!(),
+ "
+ mov x0, sp
+ bl {inner}
+ ",
+ pop_scratch!(),
+ "
+ add sp, sp, 24
+ ldr x30, [sp], #8
+ ret
+ "
+ ),
+ inner = sym inner,
+ options(noreturn),
+ );
}
--
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