From: Paul Robinson <paul.robinson@sony.com>
Date: Wed, 6 Mar 2019 19:57:43 +0000 (+0000)
Subject: [PS4] Emit a trap after a stack-protector fail call.
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=05efe0fdc472e1f57e36b7f42476946c59c7128b;p=platform%2Fupstream%2Fllvm.git

[PS4] Emit a trap after a stack-protector fail call.

llvm-svn: 355542
---

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 33921a2..31768b2 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -2537,6 +2537,12 @@ SelectionDAGBuilder::visitSPDescriptorFailure(StackProtectorDescriptor &SPD) {
   SDValue Chain =
       TLI.makeLibCall(DAG, RTLIB::STACKPROTECTOR_CHECK_FAIL, MVT::isVoid,
                       None, false, getCurSDLoc(), false, false).second;
+  // On PS4, the "return address" must still be within the calling function,
+  // even if it's at the very end, so emit an explicit TRAP here.
+  // Passing 'true' for doesNotReturn above won't generate the trap for us.
+  if (TM.getTargetTriple().isPS4CPU())
+    Chain = DAG.getNode(ISD::TRAP, getCurSDLoc(), MVT::Other, Chain);
+
   DAG.setRoot(Chain);
 }
 
diff --git a/llvm/test/CodeGen/X86/ps4-ssp-nop.ll b/llvm/test/CodeGen/X86/ps4-ssp-nop.ll
new file mode 100644
index 0000000..9fefeca
--- /dev/null
+++ b/llvm/test/CodeGen/X86/ps4-ssp-nop.ll
@@ -0,0 +1,39 @@
+; Verify that a ud2 is generated after the call to __stack_chk_fail.
+
+; RUN: llc < %s -mtriple=x86_64-scei-ps4 -enable-selectiondag-sp=false -O0 -o - | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-scei-ps4 -enable-selectiondag-sp=false -O2 -o - | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-scei-ps4 -enable-selectiondag-sp=true  -O0 -o - | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-scei-ps4 -enable-selectiondag-sp=true  -O2 -o - | FileCheck %s
+
+
+; CHECK: check_input:
+; CHECK: callq __stack_chk_fail
+; CHECK-NEXT: ud2
+; CHECK: .size	check_input
+; CHECK-NEXT: .cfi_endproc
+
+@.str = private unnamed_addr constant [37 x i8] c"????????????????????????????????????\00", align 1
+
+define signext i8 @check_input(i8* %input) nounwind uwtable ssp {
+entry:
+  %input.addr = alloca i8*, align 8
+  %buf = alloca [16 x i8], align 16
+  store i8* %input, i8** %input.addr, align 8
+  %arraydecay = getelementptr inbounds [16 x i8], [16 x i8]* %buf, i32 0, i32 0
+  %0 = load i8*, i8** %input.addr, align 8
+  %call = call i8* @strcpy(i8* %arraydecay, i8* %0) nounwind
+  %arrayidx = getelementptr inbounds [16 x i8], [16 x i8]* %buf, i32 0, i64 0
+  %1 = load i8, i8* %arrayidx, align 1
+  ret i8 %1
+}
+
+declare i8* @strcpy(i8*, i8*) nounwind
+
+define i32 @main() nounwind uwtable ssp {
+entry:
+  %retval = alloca i32, align 4
+  store i32 0, i32* %retval
+  %call = call signext i8 @check_input(i8* getelementptr inbounds ([37 x i8], [37 x i8]* @.str, i32 0, i32 0))
+  %conv = sext i8 %call to i32
+  ret i32 %conv
+}