92 lines
2.7 KiB
Rust
92 lines
2.7 KiB
Rust
//! Module for Windows x64 ABI unwind registry.
|
|
|
|
use anyhow::{bail, Result};
|
|
use cranelift_codegen::isa::{unwind::UnwindInfo, TargetIsa};
|
|
use winapi::um::winnt;
|
|
|
|
/// Represents a registry of function unwind information for Windows x64 ABI.
|
|
pub struct UnwindRegistry {
|
|
base_address: usize,
|
|
functions: Vec<winnt::RUNTIME_FUNCTION>,
|
|
published: bool,
|
|
}
|
|
|
|
impl UnwindRegistry {
|
|
/// Creates a new unwind registry with the given base address.
|
|
pub fn new(base_address: usize) -> Self {
|
|
Self {
|
|
base_address,
|
|
functions: Vec::new(),
|
|
published: false,
|
|
}
|
|
}
|
|
|
|
/// Registers a function given the start offset, length, and unwind information.
|
|
pub fn register(&mut self, func_start: u32, func_len: u32, info: &UnwindInfo) -> Result<()> {
|
|
if self.published {
|
|
bail!("unwind registry has already been published");
|
|
}
|
|
|
|
match info {
|
|
UnwindInfo::WindowsX64(_) => {
|
|
let mut entry = winnt::RUNTIME_FUNCTION::default();
|
|
|
|
entry.BeginAddress = func_start;
|
|
entry.EndAddress = func_start + func_len;
|
|
|
|
// The unwind information should be immediately following the function
|
|
// with padding for 4 byte alignment
|
|
unsafe {
|
|
*entry.u.UnwindInfoAddress_mut() = (entry.EndAddress + 3) & !3;
|
|
}
|
|
|
|
self.functions.push(entry);
|
|
|
|
Ok(())
|
|
}
|
|
_ => bail!("unsupported unwind information"),
|
|
}
|
|
}
|
|
|
|
/// Publishes all registered functions.
|
|
pub fn publish(&mut self, _isa: &dyn TargetIsa) -> Result<()> {
|
|
if self.published {
|
|
bail!("unwind registry has already been published");
|
|
}
|
|
|
|
self.published = true;
|
|
|
|
if !self.functions.is_empty() {
|
|
// Windows heap allocations are 32-bit aligned, but assert just in case
|
|
assert_eq!(
|
|
(self.functions.as_mut_ptr() as u64) % 4,
|
|
0,
|
|
"function table allocation was not aligned"
|
|
);
|
|
|
|
unsafe {
|
|
if winnt::RtlAddFunctionTable(
|
|
self.functions.as_mut_ptr(),
|
|
self.functions.len() as u32,
|
|
self.base_address as u64,
|
|
) == 0
|
|
{
|
|
bail!("failed to register function table");
|
|
}
|
|
}
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
impl Drop for UnwindRegistry {
|
|
fn drop(&mut self) {
|
|
if self.published {
|
|
unsafe {
|
|
winnt::RtlDeleteFunctionTable(self.functions.as_mut_ptr());
|
|
}
|
|
}
|
|
}
|
|
}
|