41aaa90c67
Abort when foreign exceptions are caught by catch_unwind Prior to this PR, foreign exceptions were not caught by catch_unwind, and instead passed through invisibly. This represented a painful soundness hole in some libraries ([take_mut](https://github.com/Sgeo/take_mut/blob/master/src/lib.rs#L37)), which relied on `catch_unwind` to handle all possible exit paths from a closure. With this PR, foreign exceptions are now caught by `catch_unwind` and will trigger an abort since catching foreign exceptions is currently UB according to the latest proposals by the FFI unwind project group. cc @rust-lang/wg-ffi-unwind
113 lines
3.4 KiB
Rust
113 lines
3.4 KiB
Rust
//! Implementation of panics via stack unwinding
|
|
//!
|
|
//! This crate is an implementation of panics in Rust using "most native" stack
|
|
//! unwinding mechanism of the platform this is being compiled for. This
|
|
//! essentially gets categorized into three buckets currently:
|
|
//!
|
|
//! 1. MSVC targets use SEH in the `seh.rs` file.
|
|
//! 2. Emscripten uses C++ exceptions in the `emcc.rs` file.
|
|
//! 3. All other targets use libunwind/libgcc in the `gcc.rs` file.
|
|
//!
|
|
//! More documentation about each implementation can be found in the respective
|
|
//! module.
|
|
|
|
#![no_std]
|
|
#![unstable(feature = "panic_unwind", issue = "32837")]
|
|
#![doc(
|
|
html_root_url = "https://doc.rust-lang.org/nightly/",
|
|
issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/"
|
|
)]
|
|
#![feature(core_intrinsics)]
|
|
#![feature(lang_items)]
|
|
#![feature(libc)]
|
|
#![feature(nll)]
|
|
#![feature(panic_unwind)]
|
|
#![feature(staged_api)]
|
|
#![feature(std_internals)]
|
|
#![feature(unwind_attributes)]
|
|
#![feature(abi_thiscall)]
|
|
#![feature(rustc_attrs)]
|
|
#![feature(raw)]
|
|
#![panic_runtime]
|
|
#![feature(panic_runtime)]
|
|
// `real_imp` is unused with Miri, so silence warnings.
|
|
#![cfg_attr(miri, allow(dead_code))]
|
|
|
|
use alloc::boxed::Box;
|
|
use core::any::Any;
|
|
use core::panic::BoxMeUp;
|
|
|
|
cfg_if::cfg_if! {
|
|
if #[cfg(target_os = "emscripten")] {
|
|
#[path = "emcc.rs"]
|
|
mod real_imp;
|
|
} else if #[cfg(target_os = "hermit")] {
|
|
#[path = "hermit.rs"]
|
|
mod real_imp;
|
|
} else if #[cfg(target_env = "msvc")] {
|
|
#[path = "seh.rs"]
|
|
mod real_imp;
|
|
} else if #[cfg(any(
|
|
all(target_family = "windows", target_env = "gnu"),
|
|
target_os = "cloudabi",
|
|
target_os = "psp",
|
|
target_family = "unix",
|
|
all(target_vendor = "fortanix", target_env = "sgx"),
|
|
))] {
|
|
// Rust runtime's startup objects depend on these symbols, so make them public.
|
|
#[cfg(all(target_os="windows", target_arch = "x86", target_env="gnu"))]
|
|
pub use real_imp::eh_frame_registry::*;
|
|
#[path = "gcc.rs"]
|
|
mod real_imp;
|
|
} else {
|
|
// Targets that don't support unwinding.
|
|
// - arch=wasm32
|
|
// - os=none ("bare metal" targets)
|
|
// - os=uefi
|
|
// - nvptx64-nvidia-cuda
|
|
// - arch=avr
|
|
#[path = "dummy.rs"]
|
|
mod real_imp;
|
|
}
|
|
}
|
|
|
|
cfg_if::cfg_if! {
|
|
if #[cfg(miri)] {
|
|
// Use the Miri runtime.
|
|
// We still need to also load the normal runtime above, as rustc expects certain lang
|
|
// items from there to be defined.
|
|
#[path = "miri.rs"]
|
|
mod imp;
|
|
} else {
|
|
// Use the real runtime.
|
|
use real_imp as imp;
|
|
}
|
|
}
|
|
|
|
extern "C" {
|
|
/// Handler in libstd called when a panic object is dropped outside of
|
|
/// `catch_unwind`.
|
|
fn __rust_drop_panic() -> !;
|
|
|
|
/// Handler in libstd called when a foreign exception is caught.
|
|
fn __rust_foreign_exception() -> !;
|
|
}
|
|
|
|
mod dwarf;
|
|
|
|
#[rustc_std_internal_symbol]
|
|
#[allow(improper_ctypes_definitions)]
|
|
pub unsafe extern "C" fn __rust_panic_cleanup(payload: *mut u8) -> *mut (dyn Any + Send + 'static) {
|
|
Box::into_raw(imp::cleanup(payload))
|
|
}
|
|
|
|
// Entry point for raising an exception, just delegates to the platform-specific
|
|
// implementation.
|
|
#[rustc_std_internal_symbol]
|
|
#[unwind(allowed)]
|
|
pub unsafe extern "C" fn __rust_start_panic(payload: usize) -> u32 {
|
|
let payload = payload as *mut &mut dyn BoxMeUp;
|
|
let payload = (*payload).take_box();
|
|
|
|
imp::panic(Box::from_raw(payload))
|
|
}
|