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Use push/pop scratch for aarch64 signal handler

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This commit is contained in:
Jeremy Soller
2022-08-24 12:29:48 -06:00
parent 613968dc30
commit 0ed9f03317
1 changed files with 26 additions and 114 deletions
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140
src/context/arch/aarch64.rs
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@@ -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),
);
}