[llvm] de07cde - [AArch64] Emit .cfi_negate_ra_state for PAC-auth instructions.

Daniel Kiss via llvm-commits llvm-commits at lists.llvm.org
Fri Apr 22 04:26:18 PDT 2022


Author: Daniel Kiss
Date: 2022-04-22T13:25:57+02:00
New Revision: de07cde67b5d205d58690be012106022aea6d2b3

URL: https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3
DIFF: https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3.diff

LOG: [AArch64] Emit .cfi_negate_ra_state for PAC-auth instructions.

autiasp, autibsp instructions are the counterpart of paciasp/pacibsp instructions
therefore let's emit .cfi_negate_ra_state for these too.
In case of Armv8.3 instruction set the retaa/retbb will do the return and authentication
in one step here we can't emit the . cfi_negate_ra_state because that would be point after
the ret* instruction.

Reviewed By: nickdesaulniers, MaskRay

Differential Revision: https://reviews.llvm.org/D111780

Added: 
    

Modified: 
    llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
    llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
    llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-cfi.ll
    llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-regsave.mir
    llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-sp-mod.mir
    llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-thunk.ll
    llvm/test/CodeGen/AArch64/sign-return-address.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
index 0a237265a4ed5..b6b9d60754c2c 100644
--- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
@@ -1719,7 +1719,8 @@ static void InsertReturnAddressAuth(MachineFunction &MF,
   // The AUTIASP instruction assembles to a hint instruction before v8.3a so
   // this instruction can safely used for any v8a architecture.
   // From v8.3a onwards there are optimised authenticate LR and return
-  // instructions, namely RETA{A,B}, that can be used instead.
+  // 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) {
     BuildMI(MBB, MBBI, DL,
@@ -1731,6 +1732,12 @@ static void InsertReturnAddressAuth(MachineFunction &MF,
         MBB, MBBI, DL,
         TII->get(MFI.shouldSignWithBKey() ? AArch64::AUTIBSP : AArch64::AUTIASP))
         .setMIFlag(MachineInstr::FrameDestroy);
+
+    unsigned CFIIndex =
+        MF.addFrameInst(MCCFIInstruction::createNegateRAState(nullptr));
+    BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
+        .addCFIIndex(CFIIndex)
+        .setMIFlags(MachineInstr::FrameDestroy);
   }
 }
 

diff  --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
index c913a274337ee..699bfc2d42150 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
@@ -7596,7 +7596,8 @@ static void signOutlinedFunction(MachineFunction &MF, MachineBasicBlock &MBB,
     }
 
     // If v8.3a features are available we can replace a RET instruction by
-    // RETAA or RETAB and omit the AUT instructions
+    // RETAA or RETAB and omit the AUT instructions. In this case the
+    // DW_CFA_AARCH64_negate_ra_state can't be emitted.
     if (Subtarget.hasPAuth() && MBBAUT != MBB.end() &&
         MBBAUT->getOpcode() == AArch64::RET) {
       BuildMI(MBB, MBBAUT, DL,
@@ -7609,6 +7610,11 @@ static void signOutlinedFunction(MachineFunction &MF, MachineBasicBlock &MBB,
               TII->get(ShouldSignReturnAddrWithAKey ? AArch64::AUTIASP
                                                     : AArch64::AUTIBSP))
           .setMIFlag(MachineInstr::FrameDestroy);
+      unsigned CFIIndexAuth =
+          MF.addFrameInst(MCCFIInstruction::createNegateRAState(nullptr));
+      BuildMI(MBB, MBBAUT, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
+          .addCFIIndex(CFIIndexAuth)
+          .setMIFlags(MachineInstr::FrameDestroy);
     }
   }
 }

diff  --git a/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-cfi.ll b/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-cfi.ll
index 3b61588f41ed9..74d2795db14c1 100644
--- a/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-cfi.ll
+++ b/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-cfi.ll
@@ -28,7 +28,8 @@ define void @a() "sign-return-address"="all" "sign-return-address-key"="b_key" {
 ; CHECK-NOT:          bl OUTLINED_FUNCTION_{{[0-9]+}}
 ; V8A:                hint #31
 ; V83A:               autibsp
-; CHECK-NEXT:         ret
+; V8A-NEXT, V83A-NEXT: .cfi_negate_ra_state
+; V8A-NEXT, V83A-NEXT: ret
   ret void
 }
 

diff  --git a/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-regsave.mir b/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-regsave.mir
index 5a99fe72f1082..cab5dd31a1fde 100644
--- a/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-regsave.mir
+++ b/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-regsave.mir
@@ -32,6 +32,7 @@
 # CHECK:            BL @[[OUTLINED_FUNCTION]]
 # CHECK:        bb.5:
 # CHECK:            frame-destroy AUTIBSP
+# CHECK-NEXT:       frame-destroy CFI_INSTRUCTION negate_ra_sign_state
 # CHECK-NEXT:       RET
 name:            foo
 tracksRegLiveness: true

diff  --git a/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-sp-mod.mir b/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-sp-mod.mir
index 43d3a856d6461..0bf0a98cafebc 100644
--- a/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-sp-mod.mir
+++ b/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-sp-mod.mir
@@ -81,6 +81,7 @@ body:             |
     STRXui killed renamable $x9, killed renamable $x8, target-flags(aarch64-pageoff, aarch64-nc) @v :: (volatile store (s64) into @v)
     $sp = frame-destroy ADDXri $sp, 16, 0
     frame-destroy AUTIASP implicit-def $lr, implicit killed $lr, implicit $sp
+    frame-destroy CFI_INSTRUCTION negate_ra_sign_state
     RET undef $lr
 
 # CHECK-LABEL:    name:            legal0
@@ -91,6 +92,7 @@ body:             |
 # CHECK-NEXT:           frame-setup CFI_INSTRUCTION negate_ra_sign_state
 # CHECK:                BL @[[OUTLINED_FUNC:OUTLINED_FUNCTION_[0-9]+]]
 # CHECK:                frame-destroy AUTIASP implicit-def $lr, implicit killed $lr, implicit $sp
+# CHECK-NEXT:           frame-destroy CFI_INSTRUCTION negate_ra_sign_state
 # CHECK-NEXT:           RET undef $lr
 
 ...
@@ -114,6 +116,7 @@ body:             |
     STRXui killed renamable $x9, killed renamable $x8, target-flags(aarch64-pageoff, aarch64-nc) @v :: (volatile store (s64) into @v)
     $sp = frame-destroy ADDXri $sp, 16, 0
     frame-destroy AUTIASP implicit-def $lr, implicit killed $lr, implicit $sp
+    frame-destroy CFI_INSTRUCTION negate_ra_sign_state
     RET undef $lr
 
 # CHECK-LABEL:    name:            legal1
@@ -124,6 +127,7 @@ body:             |
 # CHECK-NEXT:           frame-setup CFI_INSTRUCTION negate_ra_sign_state
 # CHECK:                BL @[[OUTLINED_FUNC]]
 # CHECK:                frame-destroy AUTIASP implicit-def $lr, implicit killed $lr, implicit $sp
+# CHECK-NEXT:           frame-destroy CFI_INSTRUCTION negate_ra_sign_state
 # CHECK-NEXT:           RET undef $lr
 
 ...
@@ -147,6 +151,7 @@ body:             |
     STRXui killed renamable $x9, killed renamable $x8, target-flags(aarch64-pageoff, aarch64-nc) @v :: (volatile store (s64) into @v)
     $sp = frame-destroy ADDXri $sp, 12, 0
     frame-destroy AUTIASP implicit-def $lr, implicit killed $lr, implicit $sp
+    frame-destroy CFI_INSTRUCTION negate_ra_sign_state
     RET undef $lr
 
 ...
@@ -170,6 +175,7 @@ body:             |
     STRXui killed renamable $x9, killed renamable $x8, target-flags(aarch64-pageoff, aarch64-nc) @v :: (volatile store (s64) into @v)
     $sp = frame-destroy ADDXri $sp, 12, 0
     frame-destroy AUTIASP implicit-def $lr, implicit killed $lr, implicit $sp
+    frame-destroy CFI_INSTRUCTION negate_ra_sign_state
     RET undef $lr
 
 # CHECK-LABEL:    name:            illegal0
@@ -180,6 +186,7 @@ body:             |
 # CHECK-NEXT:           frame-setup CFI_INSTRUCTION negate_ra_sign_state
 # CHECK-NOT:            BL @OUTLINED_FUNCTION_{{.*}}
 # CHECK:                frame-destroy AUTIASP implicit-def $lr, implicit killed $lr, implicit $sp
+# CHECK-NEXT:           frame-destroy CFI_INSTRUCTION negate_ra_sign_state
 # CHECK-NEXT:           RET undef $lr
 
 # CHECK-LABEL:    name:            illegal1
@@ -190,6 +197,7 @@ body:             |
 # CHECK-NEXT:           frame-setup CFI_INSTRUCTION negate_ra_sign_state
 # CHECK-NOT:            BL @OUTLINED_FUNCTION_{{.*}}
 # CHECK:                frame-destroy AUTIASP implicit-def $lr, implicit killed $lr, implicit $sp
+# CHECK-NEXT:           frame-destroy CFI_INSTRUCTION negate_ra_sign_state
 # CHECK-NEXT:           RET undef $lr
 
 # Outlined function that contains only legal sp modifications
@@ -203,4 +211,5 @@ body:             |
 # CHECK-NEXT:         $sp = frame-setup SUBXri $sp, 16, 0
 # CHECK:              $sp = frame-destroy ADDXri $sp, 16, 0
 # CHECK-NEXT:         frame-destroy AUTIASP implicit-def $lr, implicit $lr, implicit $sp
+# CHECK-NEXT:         frame-destroy CFI_INSTRUCTION negate_ra_sign_state
 # CHECK-NEXT:         RET $lr

diff  --git a/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-thunk.ll b/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-thunk.ll
index c3b3060308c25..525e1c96538bd 100644
--- a/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-thunk.ll
+++ b/llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-thunk.ll
@@ -11,8 +11,10 @@ define i32 @a() #0 {
 ; CHECK:        // %bb.0:                               // %entry
 ; V8A-NEXT:         hint #25
 ; V83A-NEXT:        paciasp
+; CHECK-NEXT:       .cfi_negate_ra_state
 ; V8A:              hint #29
 ; V83A:             autiasp
+; CHECK-NEXT:       .cfi_negate_ra_state
 ; CHECK-NEXT:       ret
 entry:
   %call = tail call i32 @thunk_called_fn(i32 1, i32 2, i32 3, i32 4)
@@ -28,6 +30,7 @@ define i32 @b() #0 {
 ; CHECK-NEXT:       .cfi_negate_ra_state
 ; V8A:              hint #29
 ; V83A:             autiasp
+; CHECK-NEXT:       .cfi_negate_ra_state
 ; CHECK-NEXT:       ret
 entry:
   %call = tail call i32 @thunk_called_fn(i32 1, i32 2, i32 3, i32 4)
@@ -43,6 +46,7 @@ define hidden i32 @c(i32 (i32, i32, i32, i32)* %fptr) #0 {
 ; CHECK-NEXT:       .cfi_negate_ra_state
 ; V8A:              hint #29
 ; V83A:             autiasp
+; CHECK-NEXT:       .cfi_negate_ra_state
 ; CHECK-NEXT:       ret
 entry:
   %call = tail call i32 %fptr(i32 1, i32 2, i32 3, i32 4)
@@ -58,6 +62,7 @@ define hidden i32 @d(i32 (i32, i32, i32, i32)* %fptr) #0 {
 ; CHECK-NEXT:       .cfi_negate_ra_state
 ; V8A:              hint #29
 ; V83A:             autiasp
+; CHECK-NEXT:       .cfi_negate_ra_state
 ; CHECK-NEXT:       ret
 entry:
   %call = tail call i32 %fptr(i32 1, i32 2, i32 3, i32 4)

diff  --git a/llvm/test/CodeGen/AArch64/sign-return-address.ll b/llvm/test/CodeGen/AArch64/sign-return-address.ll
index 498f82a00e98e..30a2647a0702d 100644
--- a/llvm/test/CodeGen/AArch64/sign-return-address.ll
+++ b/llvm/test/CodeGen/AArch64/sign-return-address.ll
@@ -24,7 +24,9 @@ define i32 @leaf_sign_non_leaf(i32 %x) "sign-return-address"="non-leaf"  {
 
 ; CHECK-LABEL: @leaf_sign_all
 ; CHECK:       hint #25
+; CHECK-NEXT:  .cfi_negate_ra_state
 ; CHECK:       hint #29
+; CHECK-NEXT:  .cfi_negate_ra_state
 ; CHECK:       ret
 ; CHECK-V83A:  pacia x30, sp
 ; CHECK-V83A:  retaa
@@ -34,10 +36,12 @@ define i32 @leaf_sign_all(i32 %x) "sign-return-address"="all" {
 
 ; CHECK:             @leaf_clobbers_lr
 ; CHECK:             hint #25
+; CHECK-NEXT:        .cfi_negate_ra_state
 ; CHECK-V83A:        pacia x30, sp
 ; CHECK, CHECK-V83A: str x30, [sp, #-16]!
 ; CHECK, CHECK-V83A: ldr x30, [sp], #16
 ; CHECK:             hint #29
+; CHECK-NEXT:        .cfi_negate_ra_state
 ; CHECK:             ret
 ; CHECK-V32A-NEXT:   retaa
 define i64 @leaf_clobbers_lr(i64 %x) "sign-return-address"="non-leaf"  {
@@ -49,7 +53,9 @@ declare i32 @foo(i32)
 
 ; CHECK:      @non_leaf_sign_all
 ; CHECK:      hint #25
+; CHECK-NEXT: .cfi_negate_ra_state
 ; CHECK:      hint #29
+; CHECK-NEXT: .cfi_negate_ra_state
 ; CHECK:      ret
 ; CHECK-V83A: pacia x30, sp
 ; CHECK-V83A: retaa
@@ -60,10 +66,12 @@ define i32 @non_leaf_sign_all(i32 %x) "sign-return-address"="all" {
 
 ; CHECK:             @non_leaf_sign_non_leaf
 ; CHECK:             hint #25
+; CHECK-NEXT:        .cfi_negate_ra_state
 ; CHECK-V83A:        pacia x30, sp
 ; CHECK, CHECK-V83A: str x30, [sp, #-16]!
 ; CHECK, CHECK-V83A: ldr x30, [sp], #16
 ; CHECK:             hint #29
+; CHECK-NEXT:        .cfi_negate_ra_state
 ; CHECK:             ret
 ; CHECK-V83A:        retaa
 define i32 @non_leaf_sign_non_leaf(i32 %x) "sign-return-address"="non-leaf"  {
@@ -72,10 +80,11 @@ define i32 @non_leaf_sign_non_leaf(i32 %x) "sign-return-address"="non-leaf"  {
 }
 
 ; CHECK-LABEL: @leaf_sign_all_v83
-; CHECK: pacia x30, sp
-; CHECK-NOT: ret
-; CHECK: retaa
-; CHECK-NOT: ret
+; CHECK:        pacia x30, sp
+; CHECK-NEXT:  .cfi_negate_ra_state
+; CHECK-NOT:   ret
+; CHECK:       retaa
+; CHECK-NOT:   ret
 define i32 @leaf_sign_all_v83(i32 %x) "sign-return-address"="all" "target-features"="+v8.3a" {
   ret i32 %x
 }
@@ -84,11 +93,14 @@ declare fastcc i64 @bar(i64)
 
 ; CHECK-LABEL:       @spill_lr_and_tail_call
 ; CHECK:             hint #25
+; CHECK-NEXT:        .cfi_negate_ra_state
 ; CHECK-V83A:        pacia x30, sp
+; CHECK-V83A-NEXT:  .cfi_negate_ra_state
 ; CHECK, CHECK-V83A: str x30, [sp, #-16]!
 ; CHECK, CHECK-V83A: ldr x30, [sp], #16
 ; CHECK-V83A:        autiasp
 ; CHECK:             hint #29
+; CHECK-NEXT:        .cfi_negate_ra_state
 ; CHECK:             b bar
 define fastcc void @spill_lr_and_tail_call(i64 %x) "sign-return-address"="all" {
   call void asm sideeffect "mov x30, $0", "r,~{lr}"(i64 %x) #1
@@ -97,57 +109,71 @@ define fastcc void @spill_lr_and_tail_call(i64 %x) "sign-return-address"="all" {
 }
 
 ; CHECK-LABEL: @leaf_sign_all_a_key
-; CHECK:       hint #25
-; CHECK:       hint #29
-; CHECK-V83A:  pacia x30, sp
-; CHECK-V83A:  retaa
+; CHECK:            hint #25
+; CHECK-NEXT:       .cfi_negate_ra_state
+; CHECK:            hint #29
+; CHECK-NEXT:       .cfi_negate_ra_state
+; CHECK-V83A:       pacia x30, sp
+; CHECK-V83A-NEXT:  .cfi_negate_ra_state
+; CHECK-V83A:       retaa
 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:       hint #27
-; CHECK:       hint #31
-; CHECK-V83A:  pacib x30, sp
-; CHECK-V83A:  retab
+; CHECK:            hint #27
+; CHECK-NEXT:       .cfi_negate_ra_state
+; CHECK:            hint #31
+; CHECK-NEXT:       .cfi_negate_ra_state
+; CHECK-V83A:       pacib x30, sp
+; CHECK-V83A-NEXT:  .cfi_negate_ra_state
+; CHECK-V83A:       retab
 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: pacib x30, sp
-; CHECK-NOT: ret
-; CHECK: retab
-; CHECK-NOT: ret
+; CHECK:       pacib x30, sp
+; CHECK-NEXT:  .cfi_negate_ra_state
+; 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
 }
 
 ; CHECK-LABEL: @leaf_sign_all_a_key_bti
-; CHECK-NOT:   hint #34
-; CHECK:       hint #25
-; CHECK:       hint #29
-; CHECK-V83A:  pacia x30, sp
-; CHECK-V83A:  retaa
+; CHECK-NOT:        hint #34
+; CHECK:            hint #25
+; CHECK-NEXT:       .cfi_negate_ra_state
+; CHECK:            hint #29
+; CHECK-NEXT:       .cfi_negate_ra_state
+; CHECK-V83A:       pacia x30, sp
+; CHECK-V83A-NEXT:  .cfi_negate_ra_state
+; CHECK-V83A:       retaa
 define i32 @leaf_sign_all_a_key_bti(i32 %x) "sign-return-address"="all" "sign-return-address-key"="a_key" "branch-target-enforcement"="true"{
   ret i32 %x
 }
 
 ; CHECK-LABEL: @leaf_sign_all_b_key_bti
-; CHECK-NOT:   hint #34
-; CHECK:       hint #27
-; CHECK:       hint #31
-; CHECK-V83A:  pacib x30, sp
-; CHECK-V83A:  retab
+; CHECK-NOT:        hint #34
+; CHECK:            hint #27
+; CHECK-NEXT:       .cfi_negate_ra_state
+; CHECK:            hint #31
+; CHECK-NEXT:       .cfi_negate_ra_state
+; CHECK-V83A:       pacib x30, sp
+; CHECK-V83A-NEXT:  .cfi_negate_ra_state
+; CHECK-V83A:       retab
 define i32 @leaf_sign_all_b_key_bti(i32 %x) "sign-return-address"="all" "sign-return-address-key"="b_key" "branch-target-enforcement"="true"{
   ret i32 %x
 }
 
 ; CHECK-LABEL: @leaf_sign_all_v83_b_key_bti
 ; CHECK:       pacib x30, sp
-; CHECK-NOT: ret
-; CHECK: retab
-; CHECK-NOT: ret
+; CHECK-NEXT:  .cfi_negate_ra_state
+; CHECK-NOT:   ret
+; CHECK:       retab
+; CHECK-NOT:   ret
 define i32 @leaf_sign_all_v83_b_key_bti(i32 %x) "sign-return-address"="all" "target-features"="+v8.3a" "sign-return-address-key"="b_key" "branch-target-enforcement"="true" {
   ret i32 %x
 }


        


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