When returning from a function with both SCS and PAC-RET enabled, we need to
authenticate the return address from the stack and then load from the SCS,
but this was happening in the reverse order when RETA[AB] were being used.
Fix it by disabling the use of RETA[AB] when SCS is enabled.
Fixes pr58072.
Differential Revision: https://reviews.llvm.org/D134931
// From v8.3a onwards there are optimised authenticate LR and return
// instructions, namely RETA{A,B}, that can be used instead. In this case the
// DW_CFA_AARCH64_negate_ra_state can't be emitted.
- if (Subtarget.hasPAuth() && MBBI != MBB.end() &&
- MBBI->getOpcode() == AArch64::RET_ReallyLR) {
+ if (Subtarget.hasPAuth() &&
+ !MF.getFunction().hasFnAttribute(Attribute::ShadowCallStack) &&
+ MBBI != MBB.end() && MBBI->getOpcode() == AArch64::RET_ReallyLR) {
BuildMI(MBB, MBBI, DL,
TII->get(MFI.shouldSignWithBKey() ? AArch64::RETAB : AArch64::RETAA))
.copyImplicitOps(*MBBI);
ret i32 %call
}
+; CHECK-LABEL: @non_leaf_scs
+; CHECK-NOT: retaa
+define i32 @non_leaf_scs(i32 %x) "sign-return-address"="non-leaf" shadowcallstack "target-features"="+v8.3a,+reserve-x18" {
+ %call = call i32 @foo(i32 %x)
+ ret i32 %call
+}
+
; CHECK-LABEL: @leaf_sign_all_v83
; CHECK: pacia x30, sp
; CHECK-NEXT: .cfi_negate_ra_state