24 lines
752 B
Rust
24 lines
752 B
Rust
//@ compile-flags: -C no-prepopulate-passes -Zcf-protection=full
|
|
//@ assembly-output: emit-asm
|
|
//@ needs-asm-support
|
|
//@ only-x86_64
|
|
|
|
#![crate_type = "lib"]
|
|
|
|
use std::arch::naked_asm;
|
|
|
|
// The problem at hand: Rust has adopted a fairly strict meaning for "naked functions",
|
|
// meaning "no prologue whatsoever, no, really, not one instruction."
|
|
// Unfortunately, x86's control-flow enforcement, specifically indirect branch protection,
|
|
// works by using an instruction for each possible landing site,
|
|
// and LLVM implements this via making sure of that.
|
|
#[no_mangle]
|
|
#[unsafe(naked)]
|
|
pub extern "sysv64" fn will_halt() -> ! {
|
|
// CHECK-NOT: endbr{{32|64}}
|
|
// CHECK: hlt
|
|
naked_asm!("hlt")
|
|
}
|
|
|
|
// what about aarch64?
|
|
// "branch-protection"=false
|