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Do not request sanitizers for naked functions
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Naked functions can only contain inline asm, so any instrumentation
inserted by sanitizers is illegal. Don't request it.

Fixes #129224.
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nikic committed Sep 4, 2024
1 parent 9b82580 commit 1c8f5db
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Showing 2 changed files with 47 additions and 21 deletions.
46 changes: 25 additions & 21 deletions compiler/rustc_codegen_llvm/src/attributes.rs
Original file line number Diff line number Diff line change
Expand Up @@ -411,26 +411,31 @@ pub(crate) fn llfn_attrs_from_instance<'ll, 'tcx>(
// the string "false". Now it is disabled by absence of the attribute.
to_add.push(llvm::CreateAttrStringValue(cx.llcx, "branch-target-enforcement", "false"));
}
} else if llvm_util::get_version() >= (19, 0, 0) {
// For non-naked functions, set branch protection attributes on aarch64.
if let Some(BranchProtection { bti, pac_ret }) =
cx.sess().opts.unstable_opts.branch_protection
{
assert!(cx.sess().target.arch == "aarch64");
if bti {
to_add.push(llvm::CreateAttrString(cx.llcx, "branch-target-enforcement"));
}
if let Some(PacRet { leaf, key }) = pac_ret {
to_add.push(llvm::CreateAttrStringValue(
cx.llcx,
"sign-return-address",
if leaf { "all" } else { "non-leaf" },
));
to_add.push(llvm::CreateAttrStringValue(
cx.llcx,
"sign-return-address-key",
if key == PAuthKey::A { "a_key" } else { "b_key" },
));
} else {
// Do not set sanitizer attributes for naked functions.
to_add.extend(sanitize_attrs(cx, codegen_fn_attrs.no_sanitize));

if llvm_util::get_version() >= (19, 0, 0) {
// For non-naked functions, set branch protection attributes on aarch64.
if let Some(BranchProtection { bti, pac_ret }) =
cx.sess().opts.unstable_opts.branch_protection
{
assert!(cx.sess().target.arch == "aarch64");
if bti {
to_add.push(llvm::CreateAttrString(cx.llcx, "branch-target-enforcement"));
}
if let Some(PacRet { leaf, key }) = pac_ret {
to_add.push(llvm::CreateAttrStringValue(
cx.llcx,
"sign-return-address",
if leaf { "all" } else { "non-leaf" },
));
to_add.push(llvm::CreateAttrStringValue(
cx.llcx,
"sign-return-address-key",
if key == PAuthKey::A { "a_key" } else { "b_key" },
));
}
}
}
}
Expand Down Expand Up @@ -485,7 +490,6 @@ pub(crate) fn llfn_attrs_from_instance<'ll, 'tcx>(
if let Some(backchain) = backchain_attr(cx) {
to_add.push(backchain);
}
to_add.extend(sanitize_attrs(cx, codegen_fn_attrs.no_sanitize));
to_add.extend(patchable_function_entry_attrs(cx, codegen_fn_attrs.patchable_function_entry));

// Always annotate functions with the target-cpu they are compiled for.
Expand Down
22 changes: 22 additions & 0 deletions tests/codegen/naked-asan.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,22 @@
// Make sure we do not request sanitizers for naked functions.

//@ only-x86_64
//@ needs-sanitizer-address
//@ compile-flags: -Zsanitizer=address

#![crate_type = "lib"]
#![no_std]
#![feature(abi_x86_interrupt, naked_functions)]

// CHECK: define x86_intrcc void @page_fault_handler(ptr {{.*}}%0, i64 {{.*}}%1){{.*}}#[[ATTRS:[0-9]+]] {
// CHECK-NOT: memcpy
#[naked]
#[no_mangle]
pub extern "x86-interrupt" fn page_fault_handler(_: u64, _: u64) {
unsafe {
core::arch::asm!("ud2", options(noreturn));
}
}

// CHECK: #[[ATTRS]] =
// CHECK-NOT: sanitize_address

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