AbleOS/holey-bytes
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Moved module

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This commit is contained in:
Erin 2023-11-23 17:35:11 +01:00
parent b161d46a5b
commit 5dd0e22c0d
2 changed files with 71 additions and 52 deletions
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67
hbxrt/src/linux.rs Normal file
View file

@ -0,0 +1,67 @@
use {
nix::sys::mman::{mmap, MapFlags, ProtFlags},
std::{fs::File, num::NonZeroUsize, path::Path, process::exit},
};
/// Allocate stack for program
pub unsafe fn alloc_stack(size: usize) -> nix::Result<*mut u8> {
unsafe {
Ok(mmap::<std::fs::File>(
None,
NonZeroUsize::new(size).expect("Stack size should be > 0"),
ProtFlags::PROT_GROWSDOWN | ProtFlags::PROT_READ | ProtFlags::PROT_WRITE,
MapFlags::MAP_GROWSDOWN
| MapFlags::MAP_STACK
| MapFlags::MAP_ANON
| MapFlags::MAP_PRIVATE,
None,
0,
)?
.cast())
}
}
/// Memory map bytecode
pub unsafe fn mmap_bytecode(path: impl AsRef<Path>) -> Result<*mut u8, Box<dyn std::error::Error>> {
let file = File::open(&path)?;
Ok(unsafe {
mmap(
None,
NonZeroUsize::new(file.metadata()?.len() as usize).ok_or("File is empty")?,
ProtFlags::PROT_READ,
MapFlags::MAP_PRIVATE,
Some(&file),
0,
)?
.cast()
})
}
/// Set handler for page fault
pub unsafe fn hook_pagefault() -> nix::Result<()> {
unsafe {
use nix::sys::signal;
extern "C" fn action(
_: std::ffi::c_int,
info: *mut nix::libc::siginfo_t,
_: *mut std::ffi::c_void,
) {
unsafe {
eprintln!("[E] Memory access fault at {:p}", (*info).si_addr());
exit(2);
}
}
signal::sigaction(
signal::Signal::SIGSEGV,
&nix::sys::signal::SigAction::new(
signal::SigHandler::SigAction(action),
signal::SaFlags::SA_NODEFER,
nix::sys::signalfd::SigSet::empty(),
),
)?;
}
Ok(())
}

56
hbxrt/src/main.rs
View file

@ -2,6 +2,7 @@
#![deny(unsafe_op_in_unsafe_fn)]
mod linux;
mod mem;
use {
@ -20,67 +21,18 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
};
// Allocate stack
const STACK_SIZE: usize = 1024 * 1024 * 2;
let stack_ptr = unsafe {
mmap::<std::fs::File>(
None,
NonZeroUsize::new(STACK_SIZE).expect("Stack size should be > 0"),
ProtFlags::PROT_GROWSDOWN | ProtFlags::PROT_READ | ProtFlags::PROT_WRITE,
MapFlags::MAP_GROWSDOWN
| MapFlags::MAP_STACK
| MapFlags::MAP_ANON
| MapFlags::MAP_PRIVATE,
None,
0,
)
}?;
let stack_ptr = unsafe { linux::alloc_stack(1024 * 1024 * 2) }?;
eprintln!("[I] Stack allocated at {stack_ptr:p}");
// Load program
eprintln!("[I] Loading image from \"{image_path}\"");
let file = File::open(image_path)?;
let ptr = unsafe {
mmap(
None,
NonZeroUsize::new(file.metadata()?.len() as usize).ok_or("File is empty")?,
ProtFlags::PROT_READ,
MapFlags::MAP_PRIVATE,
Some(&file),
0,
)?
};
let ptr = unsafe { linux::mmap_bytecode(image_path) }?;
eprintln!("[I] Image loaded at {ptr:p}");
let mut vm = unsafe { Vm::<_, 0>::new(mem::HostMemory, Address::new(ptr as u64)) };
vm.write_reg(254, stack_ptr as u64);
// Memory access fault handling
unsafe {
use nix::sys::signal;
extern "C" fn action(
_: std::ffi::c_int,
info: *mut nix::libc::siginfo_t,
_: *mut std::ffi::c_void,
) {
unsafe {
eprintln!("[E] Memory access fault at {:p}", (*info).si_addr());
exit(2);
}
}
signal::sigaction(
signal::Signal::SIGSEGV,
&nix::sys::signal::SigAction::new(
signal::SigHandler::SigAction(action),
signal::SaFlags::SA_NODEFER,
nix::sys::signalfd::SigSet::empty(),
),
)?;
}
unsafe { linux::hook_pagefault() }?;
// Execute program
let stat = loop {