[PATCH] D51427: [AArch64] Return address signing B key support

[Luke Cheeseman via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL345511: [AArch64] Return address signing B key support (authored by LukeCheeseman, committed by ).

Changed prior to commit:
  https://reviews.llvm.org/D51427?vs=171520&id=171523#toc

Repository:
  rL LLVM

https://reviews.llvm.org/D51427

Files:
  llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp
  llvm/trunk/test/CodeGen/AArch64/sign-return-address.ll


Index: llvm/trunk/test/CodeGen/AArch64/sign-return-address.ll
===================================================================
--- llvm/trunk/test/CodeGen/AArch64/sign-return-address.ll
+++ llvm/trunk/test/CodeGen/AArch64/sign-return-address.ll
@@ -84,3 +84,26 @@
   tail call fastcc i64 @bar(i64 %x)
   ret void
 }
+
+; CHECK-LABEL: @leaf_sign_all_a_key
+; CHECK: paciasp
+; CHECK: autiasp
+define i32 @leaf_sign_all_a_key(i32 %x) "sign-return-address"="all" "sign-return-address-key"="a_key" {
+  ret i32 %x
+}
+
+; CHECK-LABEL: @leaf_sign_all_b_key
+; CHECK: pacibsp
+; CHECK: autibsp
+define i32 @leaf_sign_all_b_key(i32 %x) "sign-return-address"="all" "sign-return-address-key"="b_key" {
+  ret i32 %x
+}
+
+; CHECK-LABEL: @leaf_sign_all_v83_b_key
+; CHECK: pacibsp
+; CHECK-NOT: ret
+; CHECK: retab
+; CHECK-NOT: ret
+define i32 @leaf_sign_all_v83_b_key(i32 %x) "sign-return-address"="all" "target-features"="+v8.3a" "sign-return-address-key"="b_key" {
+  ret i32 %x
+}
Index: llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp
===================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp
+++ llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp
@@ -597,6 +597,17 @@
   //
 }
 
+static bool ShouldSignWithAKey(MachineFunction &MF) {
+  const Function &F = MF.getFunction();
+  if (!F.hasFnAttribute("sign-return-address-key"))
+    return true;
+
+  const StringRef Key =
+      F.getFnAttribute("sign-return-address-key").getValueAsString();
+  assert(Key.equals_lower("a_key") || Key.equals_lower("b_key"));
+  return Key.equals_lower("a_key");
+}
+
 void AArch64FrameLowering::emitPrologue(MachineFunction &MF,
                                         MachineBasicBlock &MBB) const {
   MachineBasicBlock::iterator MBBI = MBB.begin();
@@ -620,7 +631,9 @@
   DebugLoc DL;
 
   if (ShouldSignReturnAddress(MF)) {
-    BuildMI(MBB, MBBI, DL, TII->get(AArch64::PACIASP))
+    BuildMI(
+        MBB, MBBI, DL,
+        TII->get(ShouldSignWithAKey(MF) ? AArch64::PACIASP : AArch64::PACIBSP))
         .setMIFlag(MachineInstr::FrameSetup);
   }
 
@@ -907,10 +920,14 @@
   // instructions, namely RETA{A,B}, that can be used instead.
   if (Subtarget.hasV8_3aOps() && MBBI != MBB.end() &&
       MBBI->getOpcode() == AArch64::RET_ReallyLR) {
-    BuildMI(MBB, MBBI, DL, TII->get(AArch64::RETAA)).copyImplicitOps(*MBBI);
+    BuildMI(MBB, MBBI, DL,
+            TII->get(ShouldSignWithAKey(MF) ? AArch64::RETAA : AArch64::RETAB))
+        .copyImplicitOps(*MBBI);
     MBB.erase(MBBI);
   } else {
-    BuildMI(MBB, MBBI, DL, TII->get(AArch64::AUTIASP))
+    BuildMI(
+        MBB, MBBI, DL,
+        TII->get(ShouldSignWithAKey(MF) ? AArch64::AUTIASP : AArch64::AUTIBSP))
         .setMIFlag(MachineInstr::FrameDestroy);
   }
 }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D51427.171523.patch
Type: text/x-patch
Size: 2805 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20181029/120fd270/attachment.bin>