[llvm] 63150f4 - Revert "Enhance stack protector for calling no return function"

Florian Hahn via llvm-commits llvm-commits at lists.llvm.org
Fri Dec 2 04:58:57 PST 2022


Author: Florian Hahn
Date: 2022-12-02T12:58:46Z
New Revision: 63150f463934bcf3a6d2945efea478d2e3250db1

URL: https://github.com/llvm/llvm-project/commit/63150f463934bcf3a6d2945efea478d2e3250db1
DIFF: https://github.com/llvm/llvm-project/commit/63150f463934bcf3a6d2945efea478d2e3250db1.diff

LOG: Revert "Enhance stack protector for calling no return function"

This reverts commit 416e8c6ad529c57f21f46c6f52ded96d3ed239fb.

This commit causes a test failure with expensive checks due to a DT
verification failure. Revert to bring bot back to green:

https://green.lab.llvm.org/green/job/clang-stage1-cmake-RA-expensive/24249/testReport/junit/LLVM/CodeGen_X86/stack_protector_no_return_ll/

+ /Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-expensive/clang-build/bin/llc /Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-expensive/llvm-project/llvm/test/CodeGen/X86/stack-protector-no-return.ll -mtriple=x86_64-unknown-linux-gnu -o -
+ /Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-expensive/clang-build/bin/FileCheck /Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-expensive/llvm-project/llvm/test/CodeGen/X86/stack-protector-no-return.ll
DominatorTree is different than a freshly computed one!
	Current:
=============================--------------------------------
Inorder Dominator Tree: DFSNumbers invalid: 0 slow queries.
  [1] %entry {4294967295,4294967295} [0]
    [2] %unreachable {4294967295,4294967295} [1]
    [2] %lpad {4294967295,4294967295} [1]
      [3] %invoke.cont {4294967295,4294967295} [2]
        [4] %invoke.cont2 {4294967295,4294967295} [3]
        [4] %SP_return3 {4294967295,4294967295} [3]
        [4] %CallStackCheckFailBlk2 {4294967295,4294967295} [3]
      [3] %lpad1 {4294967295,4294967295} [2]
        [4] %eh.resume {4294967295,4294967295} [3]
          [5] %SP_return6 {4294967295,4294967295} [4]
          [5] %CallStackCheckFailBlk5 {4294967295,4294967295} [4]
        [4] %terminate.lpad {4294967295,4294967295} [3]
          [5] %SP_return9 {4294967295,4294967295} [4]
          [5] %CallStackCheckFailBlk8 {4294967295,4294967295} [4]
    [2] %SP_return {4294967295,4294967295} [1]
    [2] %CallStackCheckFailBlk {4294967295,4294967295} [1]
Roots: %entry

Added: 
    

Modified: 
    llvm/lib/CodeGen/StackProtector.cpp
    llvm/test/CodeGen/X86/stack-protector-2.ll
    llvm/test/CodeGen/X86/stack-protector-no-return.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/StackProtector.cpp b/llvm/lib/CodeGen/StackProtector.cpp
index 2f0056f125ca6..f974bb67e440a 100644
--- a/llvm/lib/CodeGen/StackProtector.cpp
+++ b/llvm/lib/CodeGen/StackProtector.cpp
@@ -415,11 +415,11 @@ static Value *getStackGuard(const TargetLoweringBase *TLI, Module *M,
 ///
 /// Returns true if the platform/triple supports the stackprotectorcreate pseudo
 /// node.
-static bool CreatePrologue(Function *F, Module *M, Instruction *CheckLoc,
+static bool CreatePrologue(Function *F, Module *M, ReturnInst *RI,
                            const TargetLoweringBase *TLI, AllocaInst *&AI) {
   bool SupportsSelectionDAGSP = false;
   IRBuilder<> B(&F->getEntryBlock().front());
-  PointerType *PtrTy = Type::getInt8PtrTy(CheckLoc->getContext());
+  PointerType *PtrTy = Type::getInt8PtrTy(RI->getContext());
   AI = B.CreateAlloca(PtrTy, nullptr, "StackGuardSlot");
 
   Value *GuardSlot = getStackGuard(TLI, M, B, &SupportsSelectionDAGSP);
@@ -444,27 +444,14 @@ bool StackProtector::InsertStackProtectors() {
   AllocaInst *AI = nullptr; // Place on stack that stores the stack guard.
 
   for (BasicBlock &BB : llvm::make_early_inc_range(*F)) {
-    Instruction *CheckLoc = dyn_cast<ReturnInst>(BB.getTerminator());
-    if (!CheckLoc) {
-      for (auto &Inst : BB) {
-        auto *CB = dyn_cast<CallBase>(&Inst);
-        if (!CB)
-          continue;
-        if (!CB->doesNotReturn())
-          continue;
-        // Do stack check before non-return calls (e.g: __cxa_throw)
-        CheckLoc = CB;
-        break;
-      }
-    }
-
-    if (!CheckLoc)
+    ReturnInst *RI = dyn_cast<ReturnInst>(BB.getTerminator());
+    if (!RI)
       continue;
 
     // Generate prologue instrumentation if not already generated.
     if (!HasPrologue) {
       HasPrologue = true;
-      SupportsSelectionDAGSP &= CreatePrologue(F, M, CheckLoc, TLI, AI);
+      SupportsSelectionDAGSP &= CreatePrologue(F, M, RI, TLI, AI);
     }
 
     // SelectionDAG based code generation. Nothing else needs to be done here.
@@ -490,7 +477,8 @@ bool StackProtector::InsertStackProtectors() {
     // verifier guarantees that a tail call is either directly before the
     // return or with a single correct bitcast of the return value in between so
     // we don't need to worry about many situations here.
-    Instruction *Prev = CheckLoc->getPrevNonDebugInstruction();
+    Instruction *CheckLoc = RI;
+    Instruction *Prev = RI->getPrevNonDebugInstruction();
     if (Prev && isa<CallInst>(Prev) && cast<CallInst>(Prev)->isTailCall())
       CheckLoc = Prev;
     else if (Prev) {

diff  --git a/llvm/test/CodeGen/X86/stack-protector-2.ll b/llvm/test/CodeGen/X86/stack-protector-2.ll
index f2fc64ab0c866..c6971a59f813f 100644
--- a/llvm/test/CodeGen/X86/stack-protector-2.ll
+++ b/llvm/test/CodeGen/X86/stack-protector-2.ll
@@ -192,34 +192,4 @@ define dso_local void @bar_nossp(i64 %0) {
   ret void
 }
 
-; Check stack protect for noreturn call
-define dso_local i32 @foo_no_return(i32 %0) #1 {
-; CHECK-LABEL: @foo_no_return
-entry:
-  %cmp = icmp sgt i32 %0, 4
-  br i1 %cmp, label %if.then, label %if.end
-
-; CHECK:      if.then:                                          ; preds = %entry
-; CHECK-NEXT:   %StackGuard1 = load volatile i8*, i8* addrspace(257)* inttoptr (i32 40 to i8* addrspace(257)*), align 8
-; CHECK-NEXT:   %1 = load volatile i8*, i8** %StackGuardSlot, align 8
-; CHECK-NEXT:   %2 = icmp eq i8* %StackGuard1, %1
-; CHECK-NEXT:   br i1 %2, label %SP_return, label %CallStackCheckFailBlk
-; CHECK:      SP_return:                                        ; preds = %if.then
-; CHECK-NEXT:   %call = call i32 @foo_no_return(i32 1)
-; CHECK-NEXT:   br label %return
-; CHECK:      if.end:                                           ; preds = %entry
-; CHECK-NEXT:   br label %return
-
-if.then:                                          ; preds = %entry
-  %call = call i32 @foo_no_return(i32 1)
-  br label %return
-
-if.end:                                           ; preds = %entry
-  br label %return
-
-return:                                           ; preds = %if.end, %if.then
-  ret i32 0
-}
-
 attributes #0 = { sspstrong }
-attributes #1 = { noreturn sspreq}

diff  --git a/llvm/test/CodeGen/X86/stack-protector-no-return.ll b/llvm/test/CodeGen/X86/stack-protector-no-return.ll
index ce78b2b7fe759..b8ea5bd07ee5e 100644
--- a/llvm/test/CodeGen/X86/stack-protector-no-return.ll
+++ b/llvm/test/CodeGen/X86/stack-protector-no-return.ll
@@ -1,4 +1,5 @@
-; RUN: llc %s -mtriple=x86_64-unknown-linux-gnu -o - | FileCheck %s
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc %s -mtriple=x86_64-unknown-linux-gnu -o - -verify-dom-info | FileCheck %s
 
 $__clang_call_terminate = comdat any
 
@@ -7,10 +8,6 @@ $__clang_call_terminate = comdat any
 
 ; Function Attrs: mustprogress noreturn sspreq uwtable
 define dso_local void @_Z7catchesv() local_unnamed_addr #0 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
-; CHECK-LABEL: _Z7catchesv:
-; CHECK:       # %bb.0: # %entry
-; CHECK:         movq    %fs:40, %rax
-; CHECK-NEXT:    movq    %rax, 8(%rsp)
 entry:
   %exception = tail call i8* @__cxa_allocate_exception(i64 4) #8
   %0 = bitcast i8* %exception to i32*
@@ -18,17 +15,6 @@ entry:
   invoke void @__cxa_throw(i8* nonnull %exception, i8* bitcast (i8** @_ZTIi to i8*), i8* null) #9
           to label %unreachable unwind label %lpad
 
-; CHECK:         callq   __cxa_allocate_exception
-; CHECK-NEXT:    movl    $1, (%rax)
-; CHECK-NEXT:    movq    %fs:40, %rcx
-; CHECK-NEXT:    cmpq    8(%rsp), %rcx
-; CHECK-NEXT:    jne     .LBB0_12
-; CHECK-NEXT:  # %bb.1:                                # %SP_return
-; CHECK-NEXT:  .Ltmp0:
-; CHECK-NEXT:    movl    $_ZTIi, %esi
-; CHECK-NEXT:    movq    %rax, %rdi
-; CHECK-NEXT:    xorl    %edx, %edx
-; CHECK-NEXT:    callq   __cxa_throw
 
 lpad:                                             ; preds = %entry
   %1 = landingpad { i8*, i32 }
@@ -37,25 +23,11 @@ lpad:                                             ; preds = %entry
   %3 = tail call i8* @__cxa_begin_catch(i8* %2) #8
   %call = invoke i64 @write(i32 noundef 1, i8* noundef getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i64 noundef 4)
           to label %invoke.cont unwind label %lpad1
-; CHECK:         callq   __cxa_begin_catch
-; CHECK-NEXT: .Ltmp3:
-; CHECK-NEXT:    movl    $.L.str, %esi
-; CHECK-NEXT:    movl    $4, %edx
-; CHECK-NEXT:    movl    $1, %edi
-; CHECK-NEXT:    callq   write
 
 
 invoke.cont:                                      ; preds = %lpad
   invoke void @_exit(i32 noundef 1) #9
           to label %invoke.cont2 unwind label %lpad1
-; CHECK:       # %bb.3:                                # %invoke.cont
-; CHECK-NEXT:    movq    %fs:40, %rax
-; CHECK-NEXT:    cmpq    8(%rsp), %rax
-; CHECK-NEXT:    jne     .LBB0_12
-; CHECK-NEXT:  # %bb.4:                                # %SP_return3
-; CHECK-NEXT:  .Ltmp5:
-; CHECK-NEXT:    movl    $1, %edi
-; CHECK-NEXT:    callq   _exit
 
 invoke.cont2:                                     ; preds = %invoke.cont
   unreachable
@@ -65,21 +37,9 @@ lpad1:                                            ; preds = %invoke.cont, %lpad
           cleanup
   invoke void @__cxa_end_catch()
           to label %eh.resume unwind label %terminate.lpad
-; CHECK: .LBB0_6:                                # %lpad1
-; CHECK-NEXT: .Ltmp7:
-; CHECK-NEXT:   movq    %rax, %rbx
-; CHECK-NEXT: .Ltmp8:
-; CHECK-NEXT:   callq   __cxa_end_catch
 
 eh.resume:                                        ; preds = %lpad1
   resume { i8*, i32 } %4
-; CHECK:      # %bb.7:                                # %eh.resume
-; CHECK-NEXT:   movq    %fs:40, %rax
-; CHECK-NEXT:   cmpq    8(%rsp), %rax
-; CHECK-NEXT:   jne     .LBB0_12
-; CHECK-NEXT: # %bb.8:                                # %SP_return6
-; CHECK-NEXT:   movq    %rbx, %rdi
-; CHECK-NEXT:   callq   _Unwind_Resume at PLT
 
 terminate.lpad:                                   ; preds = %lpad1
   %5 = landingpad { i8*, i32 }
@@ -88,16 +48,7 @@ terminate.lpad:                                   ; preds = %lpad1
   tail call void @__clang_call_terminate(i8* %6) #10
   unreachable
 
-; CHECK: .LBB0_9:                                # %terminate.lpad
-; CHECK:        movq    %fs:40, %rcx
-; CHECK-NEXT:   cmpq    8(%rsp), %rcx
-; CHECK-NEXT:   jne     .LBB0_12
-; CHECK-NEXT: # %bb.10:                               # %SP_return9
-; CHECK-NEXT:   movq    %rax, %rdi
-; CHECK-NEXT:   callq   __clang_call_terminate
 
-; CHECK:  .LBB0_12:                               # %CallStackCheckFailBlk
-; CHECK-NEXT:   callq   __stack_chk_fail at PLT
 
 unreachable:                                      ; preds = %entry
   unreachable
@@ -125,6 +76,11 @@ declare dso_local void @__cxa_end_catch() local_unnamed_addr #1
 
 ; Function Attrs: noinline noreturn nounwind
 define linkonce_odr hidden void @__clang_call_terminate(i8* %0) local_unnamed_addr #5 comdat {
+; CHECK-LABEL: __clang_call_terminate:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq __cxa_begin_catch
+; CHECK-NEXT:    callq _ZSt9terminatev
   %2 = tail call i8* @__cxa_begin_catch(i8* %0) #8
   tail call void @_ZSt9terminatev() #10
   unreachable
@@ -142,29 +98,25 @@ define dso_local void @_Z4vulni(i32 noundef %op) local_unnamed_addr #7 {
 ; CHECK-NEXT:    movq %fs:40, %rax
 ; CHECK-NEXT:    movq %rax, (%rsp)
 ; CHECK-NEXT:    cmpl $1, %edi
-; CHECK-NEXT:    je .LBB2_1
-; CHECK-NEXT:  # %bb.3: # %if.end
+; CHECK-NEXT:    je .LBB2_3
+; CHECK-NEXT:  # %bb.1: # %if.end
 ; CHECK-NEXT:    movq %fs:40, %rax
 ; CHECK-NEXT:    cmpq (%rsp), %rax
-; CHECK-NEXT:    jne .LBB2_5
-; CHECK-NEXT:  # %bb.4: # %SP_return3
+; CHECK-NEXT:    jne .LBB2_2
+; CHECK-NEXT:  # %bb.4: # %SP_return
 ; CHECK-NEXT:    popq %rax
 ; CHECK-NEXT:    .cfi_def_cfa_offset 8
 ; CHECK-NEXT:    retq
-; CHECK-NEXT:  .LBB2_1: # %if.then
+; CHECK-NEXT:  .LBB2_3: # %if.then
 ; CHECK-NEXT:    .cfi_def_cfa_offset 16
 ; CHECK-NEXT:    movl $4, %edi
 ; CHECK-NEXT:    callq __cxa_allocate_exception
 ; CHECK-NEXT:    movl $1, (%rax)
-; CHECK-NEXT:    movq %fs:40, %rcx
-; CHECK-NEXT:    cmpq (%rsp), %rcx
-; CHECK-NEXT:    jne .LBB2_5
-; CHECK-NEXT:  # %bb.2: # %SP_return
 ; CHECK-NEXT:    movl $_ZTIi, %esi
 ; CHECK-NEXT:    movq %rax, %rdi
 ; CHECK-NEXT:    xorl %edx, %edx
 ; CHECK-NEXT:    callq __cxa_throw
-; CHECK-NEXT:  .LBB2_5: # %CallStackCheckFailBlk2
+; CHECK-NEXT:  .LBB2_2: # %CallStackCheckFailBlk
 ; CHECK-NEXT:    callq __stack_chk_fail at PLT
 entry:
   %cmp = icmp eq i32 %op, 1


        


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