forked from AbleOS/holey-bytes
Implemented traps
This commit is contained in:
parent
87ec6ded54
commit
a7cf5e4847
35
Cargo.lock
generated
35
Cargo.lock
generated
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@ -25,6 +25,12 @@ version = "1.0.0"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
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[[package]]
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name = "convert_case"
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version = "0.4.0"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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checksum = "6245d59a3e82a7fc217c5828a6692dbc6dfb63a0c8c90495621f7b9d79704a0e"
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[[package]]
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name = "delegate"
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version = "0.9.0"
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@ -36,6 +42,19 @@ dependencies = [
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"syn 1.0.109",
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]
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[[package]]
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name = "derive_more"
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version = "0.99.17"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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checksum = "4fb810d30a7c1953f91334de7244731fc3f3c10d7fe163338a35b9f640960321"
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dependencies = [
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"convert_case",
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"proc-macro2",
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"quote",
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"rustc_version",
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"syn 1.0.109",
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]
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[[package]]
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name = "fnv"
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version = "1.0.7"
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@ -70,6 +89,7 @@ name = "hbvm"
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version = "0.1.0"
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dependencies = [
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"delegate",
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"derive_more",
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"hashbrown",
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"hbbytecode",
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"log",
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@ -163,6 +183,21 @@ version = "0.6.29"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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checksum = "f162c6dd7b008981e4d40210aca20b4bd0f9b60ca9271061b07f78537722f2e1"
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[[package]]
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name = "rustc_version"
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version = "0.4.0"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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checksum = "bfa0f585226d2e68097d4f95d113b15b83a82e819ab25717ec0590d9584ef366"
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dependencies = [
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"semver",
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]
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[[package]]
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name = "semver"
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version = "1.0.17"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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checksum = "bebd363326d05ec3e2f532ab7660680f3b02130d780c299bca73469d521bc0ed"
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[[package]]
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name = "static_assertions"
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version = "1.1.0"
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@ -8,6 +8,7 @@ lto = true
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[dependencies]
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delegate = "0.9"
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derive_more = "0.99"
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hashbrown = "0.13"
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hbbytecode.path = "../hbbytecode"
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log = "0.4"
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@ -3,20 +3,3 @@ extern crate alloc;
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pub mod validate;
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pub mod vm;
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#[derive(Debug, PartialEq)]
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pub enum RuntimeErrors {
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InvalidOpcodePair(u8, u8),
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RegisterTooSmall,
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HostError(u64),
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PageNotMapped(u64),
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InvalidJumpAddress(u64),
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InvalidSystemCall(u8),
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}
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// If you solve the halting problem feel free to remove this
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#[derive(PartialEq, Debug)]
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pub enum HaltStatus {
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Halted,
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Running,
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}
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@ -1,3 +1,9 @@
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use hbvm::vm::{
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mem::{Memory, MemoryAccessReason, PageSize},
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trap::HandleTrap,
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value::Value,
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};
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use {
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hbvm::{validate::validate, vm::Vm},
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std::io::{stdin, Read},
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@ -6,13 +12,13 @@ use {
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fn main() -> Result<(), Box<dyn std::error::Error>> {
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let mut prog = vec![];
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stdin().read_to_end(&mut prog)?;
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if let Err(e) = validate(&prog) {
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eprintln!("Program validation error: {e:?}");
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return Ok(());
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} else {
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unsafe {
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let mut vm = Vm::new_unchecked(&prog);
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let mut vm = Vm::new_unchecked(&prog, TestTrapHandler);
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vm.memory.insert_test_page();
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println!("Program interrupt: {:?}", vm.run());
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println!("{:?}", vm.registers);
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@ -24,3 +30,30 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
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pub fn time() -> u32 {
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9
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}
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struct TestTrapHandler;
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impl HandleTrap for TestTrapHandler {
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fn page_fault(
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&mut self,
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_: MemoryAccessReason,
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_: &mut Memory,
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_: u64,
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_: PageSize,
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_: *mut u8,
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) -> bool {
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false
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}
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fn invalid_op(&mut self, _: &mut [Value; 256], _: &mut usize, _: &mut Memory, _: u8) -> bool
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where
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Self: Sized,
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{
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false
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}
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fn ecall(&mut self, _: &mut [Value; 256], _: &mut usize, _: &mut Memory)
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where
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Self: Sized,
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{
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}
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}
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@ -1,21 +1,31 @@
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/// Program validation error kind
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#[derive(Clone, Copy, Debug, PartialEq, Eq)]
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pub enum ErrorKind {
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/// Unknown opcode
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InvalidInstruction,
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/// VM doesn't implement this valid opcode
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Unimplemented,
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/// Attempted to copy over register boundary
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RegisterArrayOverflow,
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}
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/// Error
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#[derive(Clone, Copy, Debug, PartialEq, Eq)]
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pub struct Error {
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/// Kind
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pub kind: ErrorKind,
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/// Location in bytecode
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pub index: usize,
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}
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/// Perform bytecode validation. If it passes, the program should be
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/// sound to execute.
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pub fn validate(mut program: &[u8]) -> Result<(), Error> {
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use hbbytecode::opcode::*;
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let start = program;
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loop {
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// Match on instruction types and perform necessary checks
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program = match program {
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[] => return Ok(()),
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[LD..=ST, reg, _, _, _, _, _, _, _, _, _, count, ..]
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@ -1,10 +1,16 @@
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mod paging;
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use self::paging::{PageTable, Permission, PtEntry};
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use alloc::boxed::Box;
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use core::mem::MaybeUninit;
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use self::paging::{PageTable, Permission, PtEntry};
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use super::{trap::HandleTrap, VmRunError};
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use alloc::boxed::Box;
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use derive_more::Display;
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/// HoleyBytes virtual memory
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#[derive(Clone, Debug)]
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pub struct Memory {
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/// Root page table
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root_pt: *mut PageTable,
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}
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@ -47,13 +53,23 @@ impl Memory {
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entry = PtEntry::new(Box::into_raw(pt) as _, Permission::Node);
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}
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self.root_pt_mut()[0] = entry;
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(*self.root_pt)[0] = entry;
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}
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}
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/// Load value from an address
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pub unsafe fn load(&self, addr: u64, target: *mut u8, count: usize) -> Result<(), ()> {
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///
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/// # Safety
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/// Applies same conditions as for [`core::ptr::copy_nonoverlapping`]
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pub unsafe fn load(
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&mut self,
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addr: u64,
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target: *mut u8,
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count: usize,
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traph: &mut impl HandleTrap,
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) -> Result<(), LoadError> {
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self.memory_access(
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MemoryAccessReason::Load,
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addr,
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target,
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count,
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@ -64,96 +80,193 @@ impl Memory {
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)
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},
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|src, dst, count| core::ptr::copy_nonoverlapping(src, dst, count),
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traph,
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)
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.map_err(|_| LoadError)
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}
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/// Store value to an address
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pub unsafe fn store(&mut self, addr: u64, source: *const u8, count: usize) -> Result<(), ()> {
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///
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/// # Safety
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/// Applies same conditions as for [`core::ptr::copy_nonoverlapping`]
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pub unsafe fn store(
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&mut self,
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addr: u64,
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source: *const u8,
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count: usize,
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traph: &mut impl HandleTrap,
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) -> Result<(), StoreError> {
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self.memory_access(
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MemoryAccessReason::Store,
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addr,
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source.cast_mut(),
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count,
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|perm| perm == Permission::Write,
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|dst, src, count| core::ptr::copy_nonoverlapping(src, dst, count),
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traph,
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)
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.map_err(|_| StoreError)
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}
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/// Copy a block of memory
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pub unsafe fn block_copy(&mut self, src: u64, dst: u64, count: u64) -> Result<(), ()> {
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let count = usize::try_from(count).expect("?conradluget a better CPU");
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///
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/// # Safety
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/// - Same as for [`Self::load`] and [`Self::store`]
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/// - Your faith in the gods of UB
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/// - Addr-san claims it's fine but who knows is she isn't lying :ferrisSus:
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pub unsafe fn block_copy(
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&mut self,
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src: u64,
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dst: u64,
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count: usize,
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traph: &mut impl HandleTrap,
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) -> Result<(), MemoryAccessReason> {
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// Yea, i know it is possible to do this more efficiently, but I am too lazy.
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let mut srcs = PageSplitter::new(src, count, self.root_pt);
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let mut dsts = PageSplitter::new(dst, count, self.root_pt);
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let mut c_src = srcs.next().ok_or(())?;
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let mut c_dst = dsts.next().ok_or(())?;
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const STACK_BUFFER_SIZE: usize = 512;
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loop {
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let min_size = c_src.size.min(c_dst.size);
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// Decide if to use stack-allocated buffer or to heap allocate
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// Deallocation is again decided on size at the end of the function
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let mut buf = MaybeUninit::<[u8; STACK_BUFFER_SIZE]>::uninit();
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let buf = if count <= STACK_BUFFER_SIZE {
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buf.as_mut_ptr().cast()
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} else {
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unsafe {
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core::ptr::copy(c_src.ptr, c_dst.ptr, min_size);
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}
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let layout = core::alloc::Layout::from_size_align_unchecked(count, 1);
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let ptr = alloc::alloc::alloc(layout);
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if ptr.is_null() {
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alloc::alloc::handle_alloc_error(layout);
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}
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match (
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match c_src.size.saturating_sub(min_size) {
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0 => srcs.next(),
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size => Some(PageSplitResult { size, ..c_src }),
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},
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match c_dst.size.saturating_sub(min_size) {
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0 => dsts.next(),
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size => Some(PageSplitResult { size, ..c_dst }),
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},
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) {
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(None, None) => return Ok(()),
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(Some(src), Some(dst)) => (c_src, c_dst) = (src, dst),
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_ => return Err(()),
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ptr
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}
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};
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// Perform memory block transfer
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let status = (|| {
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// Load to buffer
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self.memory_access(
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MemoryAccessReason::Load,
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src,
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buf,
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count,
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|perm| {
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matches!(
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perm,
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Permission::Readonly | Permission::Write | Permission::Exec
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)
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},
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|src, dst, count| core::ptr::copy(src, dst, count),
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traph,
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)
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.map_err(|_| MemoryAccessReason::Load)?;
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// Store from buffer
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self.memory_access(
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MemoryAccessReason::Store,
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dst,
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buf,
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count,
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|perm| perm == Permission::Write,
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|dst, src, count| core::ptr::copy(src, dst, count),
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traph,
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)
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.map_err(|_| MemoryAccessReason::Store)?;
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Ok::<_, MemoryAccessReason>(())
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})();
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// Deallocate if used heap-allocated array
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if count > STACK_BUFFER_SIZE {
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alloc::alloc::dealloc(
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buf,
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core::alloc::Layout::from_size_align_unchecked(count, 1),
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);
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}
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status
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}
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#[inline]
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pub fn root_pt(&self) -> &PageTable {
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unsafe { &*self.root_pt }
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}
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#[inline]
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pub fn root_pt_mut(&mut self) -> &mut PageTable {
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unsafe { &mut *self.root_pt }
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}
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/// Split address to pages, check their permissions and feed pointers with offset
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/// to a specified function.
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///
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/// If page is not found, execute page fault trap handler.
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#[allow(clippy::too_many_arguments)] // Silence peasant
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fn memory_access(
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&self,
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&mut self,
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reason: MemoryAccessReason,
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src: u64,
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mut dst: *mut u8,
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len: usize,
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permission_check: impl Fn(Permission) -> bool,
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action: impl Fn(*mut u8, *mut u8, usize),
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permission_check: fn(Permission) -> bool,
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action: fn(*mut u8, *mut u8, usize),
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traph: &mut impl HandleTrap,
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) -> Result<(), ()> {
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for PageSplitResult { ptr, size, perm } in PageSplitter::new(src, len, self.root_pt) {
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if !permission_check(perm) {
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return Err(());
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let mut pspl = AddrSplitter::new(src, len, self.root_pt);
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loop {
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match pspl.next() {
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// Page found
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Some(Ok(AddrSplitOk { ptr, size, perm })) => {
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if !permission_check(perm) {
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return Err(());
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}
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// Perform memory action and bump dst pointer
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action(ptr, dst, size);
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dst = unsafe { dst.add(size) };
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}
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Some(Err(AddrSplitError { addr, size })) => {
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// Execute page fault handler
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if traph.page_fault(reason, self, addr, size, dst) {
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// Shift the splitter address
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pspl.bump(size);
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// Bump dst pointer
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dst = unsafe { dst.add(size as _) };
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} else {
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return Err(()); // Unhandleable
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}
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}
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None => return Ok(()),
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}
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action(ptr, dst, size);
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dst = unsafe { dst.add(size) };
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}
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Ok(())
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}
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}
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struct PageSplitResult {
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/// Result from address split
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struct AddrSplitOk {
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/// Pointer to the start for perform operation
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ptr: *mut u8,
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/// Size to the end of page / end of desired size
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size: usize,
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/// Page permission
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perm: Permission,
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}
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struct PageSplitter {
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struct AddrSplitError {
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/// Address of failure
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addr: u64,
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|
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/// Requested page size
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size: PageSize,
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}
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/// Address splitter into pages
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struct AddrSplitter {
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/// Current address
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addr: u64,
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/// Size left
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size: usize,
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/// Page table
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pagetable: *const PageTable,
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}
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impl PageSplitter {
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impl AddrSplitter {
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/// Create a new page splitter
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pub const fn new(addr: u64, size: usize, pagetable: *const PageTable) -> Self {
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Self {
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addr,
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|
@ -161,19 +274,29 @@ impl PageSplitter {
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pagetable,
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}
|
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}
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/// Bump address by size X
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fn bump(&mut self, page_size: PageSize) {
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self.addr += page_size as u64;
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self.size = self.size.saturating_sub(page_size as _);
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}
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}
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impl Iterator for PageSplitter {
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type Item = PageSplitResult;
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impl Iterator for AddrSplitter {
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type Item = Result<AddrSplitOk, AddrSplitError>;
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|
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fn next(&mut self) -> Option<Self::Item> {
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// The end, everything is fine
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if self.size == 0 {
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return None;
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}
|
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|
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let (base, perm, size, offset) = 'a: {
|
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let mut current_pt = self.pagetable;
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|
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// Walk the page table
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for lvl in (0..5).rev() {
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// Get an entry
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unsafe {
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let entry = (*current_pt).get_unchecked(
|
||||
usize::try_from((self.addr >> (lvl * 9 + 12)) & ((1 << 9) - 1))
|
||||
|
@ -182,34 +305,102 @@ impl Iterator for PageSplitter {
|
|||
|
||||
let ptr = entry.ptr();
|
||||
match entry.permission() {
|
||||
Permission::Empty => return None,
|
||||
// No page → page fault
|
||||
Permission::Empty => {
|
||||
return Some(Err(AddrSplitError {
|
||||
addr: self.addr,
|
||||
size: PageSize::from_lvl(lvl)?,
|
||||
}))
|
||||
}
|
||||
|
||||
// Node → proceed waking
|
||||
Permission::Node => current_pt = ptr as _,
|
||||
|
||||
// Leaft → return relevant data
|
||||
perm => {
|
||||
break 'a (
|
||||
// Pointer in host memory
|
||||
ptr as *mut u8,
|
||||
perm,
|
||||
match lvl {
|
||||
0 => 4096,
|
||||
1 => 1024_usize.pow(2) * 2,
|
||||
2 => 1024_usize.pow(3),
|
||||
_ => return None,
|
||||
},
|
||||
PageSize::from_lvl(lvl)?,
|
||||
// In-page offset
|
||||
self.addr as usize & ((1 << (lvl * 9 + 12)) - 1),
|
||||
)
|
||||
);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
return None;
|
||||
return None; // Reached the end (should not happen)
|
||||
};
|
||||
|
||||
let avail = (size - offset).clamp(0, self.size);
|
||||
self.addr += size as u64;
|
||||
self.size = self.size.saturating_sub(size);
|
||||
Some(PageSplitResult {
|
||||
ptr: unsafe { base.add(offset) },
|
||||
// Get available byte count in the selected page with offset
|
||||
let avail = (size as usize - offset).clamp(0, self.size);
|
||||
self.bump(size);
|
||||
|
||||
Some(Ok(AddrSplitOk {
|
||||
ptr: unsafe { base.add(offset) }, // Return pointer to the start of region
|
||||
size: avail,
|
||||
perm,
|
||||
})
|
||||
}))
|
||||
}
|
||||
}
|
||||
|
||||
/// Page size
|
||||
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
|
||||
pub enum PageSize {
|
||||
/// 4 KiB page (on level 0)
|
||||
Size4K = 4096,
|
||||
|
||||
/// 2 MiB page (on level 1)
|
||||
Size2M = 1024 * 1024 * 2,
|
||||
|
||||
/// 1 GiB page (on level 2)
|
||||
Size1G = 1024 * 1024 * 1024,
|
||||
}
|
||||
|
||||
impl PageSize {
|
||||
/// Convert page table level to size of page
|
||||
fn from_lvl(lvl: u8) -> Option<Self> {
|
||||
match lvl {
|
||||
0 => Some(PageSize::Size4K),
|
||||
1 => Some(PageSize::Size2M),
|
||||
2 => Some(PageSize::Size1G),
|
||||
_ => None,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// Unhandled load access trap
|
||||
#[derive(Clone, Copy, Display, Debug, PartialEq, Eq)]
|
||||
pub struct LoadError;
|
||||
|
||||
/// Unhandled store access trap
|
||||
#[derive(Clone, Copy, Display, Debug, PartialEq, Eq)]
|
||||
pub struct StoreError;
|
||||
|
||||
#[derive(Clone, Copy, Display, Debug, PartialEq, Eq)]
|
||||
pub enum MemoryAccessReason {
|
||||
Load,
|
||||
Store,
|
||||
}
|
||||
|
||||
impl From<MemoryAccessReason> for VmRunError {
|
||||
fn from(value: MemoryAccessReason) -> Self {
|
||||
match value {
|
||||
MemoryAccessReason::Load => Self::LoadAccessEx,
|
||||
MemoryAccessReason::Store => Self::StoreAccessEx,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl From<LoadError> for VmRunError {
|
||||
fn from(_: LoadError) -> Self {
|
||||
Self::LoadAccessEx
|
||||
}
|
||||
}
|
||||
|
||||
impl From<StoreError> for VmRunError {
|
||||
fn from(_: StoreError) -> Self {
|
||||
Self::StoreAccessEx
|
||||
}
|
||||
}
|
||||
|
|
|
@ -6,30 +6,40 @@ use core::{
|
|||
};
|
||||
use delegate::delegate;
|
||||
|
||||
/// Page entry permission
|
||||
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
|
||||
#[repr(u8)]
|
||||
pub enum Permission {
|
||||
/// No page present
|
||||
#[default]
|
||||
Empty,
|
||||
/// Points to another pagetable
|
||||
Node,
|
||||
/// Page is read only
|
||||
Readonly,
|
||||
/// Page is readable and writable
|
||||
Write,
|
||||
/// Page is readable and executable
|
||||
Exec,
|
||||
}
|
||||
|
||||
/// Page table entry
|
||||
#[derive(Clone, Copy, Default, PartialEq, Eq)]
|
||||
pub struct PtEntry(u64);
|
||||
impl PtEntry {
|
||||
/// Create new
|
||||
#[inline]
|
||||
pub unsafe fn new(ptr: *mut PtPointedData, permission: Permission) -> Self {
|
||||
Self(ptr as u64 | permission as u64)
|
||||
}
|
||||
|
||||
/// Get permission
|
||||
#[inline]
|
||||
pub fn permission(&self) -> Permission {
|
||||
unsafe { core::mem::transmute(self.0 as u8 & 0b111) }
|
||||
}
|
||||
|
||||
/// Get pointer to the data (leaf) or next page table (node)
|
||||
#[inline]
|
||||
pub fn ptr(&self) -> *mut PtPointedData {
|
||||
(self.0 & !((1 << 12) - 1)) as _
|
||||
|
@ -45,6 +55,8 @@ impl Debug for PtEntry {
|
|||
}
|
||||
}
|
||||
|
||||
|
||||
/// Page table
|
||||
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
|
||||
#[repr(align(4096))]
|
||||
pub struct PageTable([PtEntry; 512]);
|
||||
|
@ -89,13 +101,17 @@ where
|
|||
|
||||
impl Default for PageTable {
|
||||
fn default() -> Self {
|
||||
// SAFETY: It's fine, zeroed page table entry is valid (= empty)
|
||||
Self(unsafe { MaybeUninit::zeroed().assume_init() })
|
||||
}
|
||||
}
|
||||
|
||||
/// Data page table entry can possibly point to
|
||||
#[derive(Clone, Copy)]
|
||||
#[repr(C, align(4096))]
|
||||
pub union PtPointedData {
|
||||
/// Node - next page table
|
||||
pub pt: PageTable,
|
||||
/// Leaf
|
||||
pub page: u8,
|
||||
}
|
||||
|
|
|
@ -11,8 +11,11 @@
|
|||
// program size. If you are (rightfully) worried about the UB, for now just
|
||||
// append your program with 11 zeroes.
|
||||
|
||||
mod mem;
|
||||
mod value;
|
||||
use self::trap::HandleTrap;
|
||||
|
||||
pub mod mem;
|
||||
pub mod trap;
|
||||
pub mod value;
|
||||
|
||||
use {
|
||||
crate::validate,
|
||||
|
@ -23,6 +26,7 @@ use {
|
|||
value::Value,
|
||||
};
|
||||
|
||||
/// Extract a parameter from program
|
||||
macro_rules! param {
|
||||
($self:expr, $ty:ty) => {{
|
||||
assert_impl_one!($ty: OpParam);
|
||||
|
@ -37,6 +41,7 @@ macro_rules! param {
|
|||
}};
|
||||
}
|
||||
|
||||
/// Perform binary operation `#0 ← #1 OP #2`
|
||||
macro_rules! binary_op {
|
||||
($self:expr, $ty:ident, $handler:expr) => {{
|
||||
let ParamBBB(tg, a0, a1) = param!($self, ParamBBB);
|
||||
|
@ -51,6 +56,7 @@ macro_rules! binary_op {
|
|||
}};
|
||||
}
|
||||
|
||||
/// Perform binary operation with immediate `#0 ← #1 OP imm #2`
|
||||
macro_rules! binary_op_imm {
|
||||
($self:expr, $ty:ident, $handler:expr) => {{
|
||||
let ParamBBD(tg, a0, imm) = param!($self, ParamBBD);
|
||||
|
@ -61,6 +67,7 @@ macro_rules! binary_op_imm {
|
|||
}};
|
||||
}
|
||||
|
||||
/// Jump at `#3` if ordering on `#0 <=> #1` is equal to expected
|
||||
macro_rules! cond_jump {
|
||||
($self:expr, $ty:ident, $expected:ident) => {{
|
||||
let ParamBBD(a0, a1, jt) = param!($self, ParamBBD);
|
||||
|
@ -72,36 +79,59 @@ macro_rules! cond_jump {
|
|||
}};
|
||||
}
|
||||
|
||||
pub struct Vm<'a> {
|
||||
/// HoleyBytes Virtual Machine
|
||||
pub struct Vm<'a, T> {
|
||||
/// Holds 256 registers
|
||||
///
|
||||
/// Writing to register 0 is considered undefined behaviour
|
||||
/// in terms of HoleyBytes program execution
|
||||
pub registers: [Value; 256],
|
||||
|
||||
/// Memory implementation
|
||||
pub memory: Memory,
|
||||
|
||||
/// Trap handler
|
||||
pub traph: T,
|
||||
|
||||
// Program counter
|
||||
pc: usize,
|
||||
|
||||
/// Program
|
||||
program: &'a [u8],
|
||||
}
|
||||
|
||||
impl<'a> Vm<'a> {
|
||||
impl<'a, T: HandleTrap> Vm<'a, T> {
|
||||
/// Create a new VM with program and trap handler
|
||||
///
|
||||
/// # Safety
|
||||
/// Program code has to be validated
|
||||
pub unsafe fn new_unchecked(program: &'a [u8]) -> Self {
|
||||
pub unsafe fn new_unchecked(program: &'a [u8], traph: T) -> Self {
|
||||
Self {
|
||||
registers: [Value::from(0_u64); 256],
|
||||
memory: Default::default(),
|
||||
traph,
|
||||
pc: 0,
|
||||
program,
|
||||
}
|
||||
}
|
||||
|
||||
pub fn new_validated(program: &'a [u8]) -> Result<Self, validate::Error> {
|
||||
/// Create a new VM with program and trap handler only if it passes validation
|
||||
pub fn new_validated(program: &'a [u8], traph: T) -> Result<Self, validate::Error> {
|
||||
validate::validate(program)?;
|
||||
Ok(unsafe { Self::new_unchecked(program) })
|
||||
Ok(unsafe { Self::new_unchecked(program, traph) })
|
||||
}
|
||||
|
||||
pub fn run(&mut self) -> HaltReason {
|
||||
/// Execute program
|
||||
///
|
||||
/// Program can return [`VmRunError`] if a trap handling failed
|
||||
pub fn run(&mut self) -> Result<(), VmRunError> {
|
||||
use hbbytecode::opcode::*;
|
||||
loop {
|
||||
// Fetch instruction
|
||||
let Some(&opcode) = self.program.get(self.pc)
|
||||
else { return HaltReason::ProgramEnd };
|
||||
else { return Ok(()) };
|
||||
|
||||
// Big match
|
||||
unsafe {
|
||||
match opcode {
|
||||
NOP => param!(self, ()),
|
||||
|
@ -196,45 +226,30 @@ impl<'a> Vm<'a> {
|
|||
_ => 0,
|
||||
};
|
||||
|
||||
if self
|
||||
.memory
|
||||
.load(
|
||||
self.read_reg(base).as_u64() + off + n as u64,
|
||||
self.registers.as_mut_ptr().add(usize::from(dst) + n).cast(),
|
||||
usize::from(count).saturating_sub(n),
|
||||
)
|
||||
.is_err()
|
||||
{
|
||||
return HaltReason::LoadAccessEx;
|
||||
}
|
||||
self.memory.load(
|
||||
self.read_reg(base).as_u64() + off + n as u64,
|
||||
self.registers.as_mut_ptr().add(usize::from(dst) + n).cast(),
|
||||
usize::from(count).saturating_sub(n),
|
||||
&mut self.traph,
|
||||
)?;
|
||||
}
|
||||
ST => {
|
||||
let ParamBBDH(dst, base, off, count) = param!(self, ParamBBDH);
|
||||
if self
|
||||
.memory
|
||||
.store(
|
||||
self.read_reg(base).as_u64() + off,
|
||||
self.registers.as_ptr().add(usize::from(dst)).cast(),
|
||||
count.into(),
|
||||
)
|
||||
.is_err()
|
||||
{
|
||||
return HaltReason::LoadAccessEx;
|
||||
}
|
||||
self.memory.store(
|
||||
self.read_reg(base).as_u64() + off,
|
||||
self.registers.as_ptr().add(usize::from(dst)).cast(),
|
||||
count.into(),
|
||||
&mut self.traph,
|
||||
)?;
|
||||
}
|
||||
BMC => {
|
||||
let ParamBBD(src, dst, count) = param!(self, ParamBBD);
|
||||
if self
|
||||
.memory
|
||||
.block_copy(
|
||||
self.read_reg(src).as_u64(),
|
||||
self.read_reg(dst).as_u64(),
|
||||
count,
|
||||
)
|
||||
.is_err()
|
||||
{
|
||||
return HaltReason::LoadAccessEx;
|
||||
}
|
||||
self.memory.block_copy(
|
||||
self.read_reg(src).as_u64(),
|
||||
self.read_reg(dst).as_u64(),
|
||||
count as _,
|
||||
&mut self.traph,
|
||||
)?;
|
||||
}
|
||||
BRC => {
|
||||
let ParamBBB(src, dst, count) = param!(self, ParamBBB);
|
||||
|
@ -261,7 +276,8 @@ impl<'a> Vm<'a> {
|
|||
JGTU => cond_jump!(self, sint, Greater),
|
||||
ECALL => {
|
||||
param!(self, ());
|
||||
return HaltReason::Ecall;
|
||||
self.traph
|
||||
.ecall(&mut self.registers, &mut self.pc, &mut self.memory);
|
||||
}
|
||||
ADDF => binary_op!(self, as_f64, ops::Add::add),
|
||||
MULF => binary_op!(self, as_f64, ops::Mul::mul),
|
||||
|
@ -274,21 +290,29 @@ impl<'a> Vm<'a> {
|
|||
}
|
||||
ADDFI => binary_op_imm!(self, as_f64, ops::Add::add),
|
||||
MULFI => binary_op_imm!(self, as_f64, ops::Mul::mul),
|
||||
_ => return HaltReason::InvalidOpcode,
|
||||
op => {
|
||||
if !self.traph.invalid_op(
|
||||
&mut self.registers,
|
||||
&mut self.pc,
|
||||
&mut self.memory,
|
||||
op,
|
||||
) {
|
||||
return Err(VmRunError::InvalidOpcodeEx);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// Read register
|
||||
#[inline]
|
||||
unsafe fn read_reg(&self, n: u8) -> Value {
|
||||
if n == 0 {
|
||||
0_u64.into()
|
||||
} else {
|
||||
*self.registers.get_unchecked(n as usize)
|
||||
}
|
||||
*self.registers.get_unchecked(n as usize)
|
||||
}
|
||||
|
||||
/// Write a register.
|
||||
/// Writing to register 0 is no-op.
|
||||
#[inline]
|
||||
unsafe fn write_reg(&mut self, n: u8, value: Value) {
|
||||
if n != 0 {
|
||||
|
@ -297,12 +321,16 @@ impl<'a> Vm<'a> {
|
|||
}
|
||||
}
|
||||
|
||||
/// Virtual machine halt error
|
||||
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
|
||||
#[repr(u8)]
|
||||
pub enum HaltReason {
|
||||
ProgramEnd,
|
||||
Ecall,
|
||||
InvalidOpcode,
|
||||
pub enum VmRunError {
|
||||
/// Unhandled invalid opcode exceptions
|
||||
InvalidOpcodeEx,
|
||||
|
||||
/// Unhandled load access exception
|
||||
LoadAccessEx,
|
||||
|
||||
/// Unhandled store access exception
|
||||
StoreAccessEx,
|
||||
}
|
||||
|
|
33
hbvm/src/vm/trap.rs
Normal file
33
hbvm/src/vm/trap.rs
Normal file
|
@ -0,0 +1,33 @@
|
|||
use super::{
|
||||
mem::{Memory, MemoryAccessReason, PageSize},
|
||||
value::Value,
|
||||
};
|
||||
|
||||
/// Handle VM traps
|
||||
pub trait HandleTrap {
|
||||
/// Handle page fault
|
||||
fn page_fault(
|
||||
&mut self,
|
||||
reason: MemoryAccessReason,
|
||||
memory: &mut Memory,
|
||||
vaddr: u64,
|
||||
size: PageSize,
|
||||
dataptr: *mut u8,
|
||||
) -> bool;
|
||||
|
||||
/// Handle invalid opcode exception
|
||||
fn invalid_op(
|
||||
&mut self,
|
||||
regs: &mut [Value; 256],
|
||||
pc: &mut usize,
|
||||
memory: &mut Memory,
|
||||
op: u8,
|
||||
) -> bool
|
||||
where
|
||||
Self: Sized;
|
||||
|
||||
/// Handle environment calls
|
||||
fn ecall(&mut self, regs: &mut [Value; 256], pc: &mut usize, memory: &mut Memory)
|
||||
where
|
||||
Self: Sized;
|
||||
}
|
|
@ -1,7 +1,13 @@
|
|||
use core::fmt::Debug;
|
||||
|
||||
/// Define [`Value`] union
|
||||
///
|
||||
/// # Safety
|
||||
/// Union variants have to be sound to byte-reinterpretate
|
||||
/// between each other. Otherwise the behaviour is undefined.
|
||||
macro_rules! value_def {
|
||||
($($ty:ident),* $(,)?) => {
|
||||
/// HBVM register value
|
||||
#[derive(Copy, Clone)]
|
||||
#[repr(packed)]
|
||||
pub union Value {
|
||||
|
@ -10,6 +16,7 @@ macro_rules! value_def {
|
|||
|
||||
paste::paste! {
|
||||
impl Value {$(
|
||||
#[doc = "Byte-reinterpret [`Value`] as [`" $ty "`]"]
|
||||
#[inline]
|
||||
pub fn [<as_ $ty>](&self) -> $ty {
|
||||
unsafe { self.$ty }
|
||||
|
@ -29,9 +36,11 @@ macro_rules! value_def {
|
|||
}
|
||||
|
||||
value_def!(u64, i64, f64);
|
||||
static_assertions::const_assert_eq!(core::mem::size_of::<Value>(), 8);
|
||||
|
||||
impl Debug for Value {
|
||||
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
|
||||
self.as_u64().fmt(f)
|
||||
// Print formatted as hexadecimal, unsigned integer
|
||||
write!(f, "{:x}", self.as_u64())
|
||||
}
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue