[llvm] r363169 - StackProtector: Use PointerMayBeCaptured
Matt Arsenault via llvm-commits
llvm-commits at lists.llvm.org
Wed Jun 12 07:23:34 PDT 2019
Author: arsenm
Date: Wed Jun 12 07:23:33 2019
New Revision: 363169
URL: http://llvm.org/viewvc/llvm-project?rev=363169&view=rev
Log:
StackProtector: Use PointerMayBeCaptured
This was using its own, outdated list of possible captures. This was
at minimum not catching cmpxchg and addrspacecast captures.
One change is now any volatile access is treated as capturing. The
test coverage for this pass is quite inadequate, but this required
removing volatile in the lifetime capture test.
Also fixes some infrastructure issues to allow running just the IR
pass.
Fixes bug 42238.
Added:
llvm/trunk/test/Transforms/StackProtector/
llvm/trunk/test/Transforms/StackProtector/X86/
llvm/trunk/test/Transforms/StackProtector/X86/captures.ll
llvm/trunk/test/Transforms/StackProtector/X86/lit.local.cfg
Modified:
llvm/trunk/include/llvm/CodeGen/StackProtector.h
llvm/trunk/lib/CodeGen/StackProtector.cpp
llvm/trunk/test/CodeGen/X86/stack-protector.ll
llvm/trunk/tools/opt/opt.cpp
Modified: llvm/trunk/include/llvm/CodeGen/StackProtector.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/StackProtector.h?rev=363169&r1=363168&r2=363169&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/StackProtector.h (original)
+++ llvm/trunk/include/llvm/CodeGen/StackProtector.h Wed Jun 12 07:23:33 2019
@@ -61,12 +61,6 @@ private:
/// protection when -fstack-protection is used.
unsigned SSPBufferSize = 0;
- /// VisitedPHIs - The set of PHI nodes visited when determining
- /// if a variable's reference has been taken. This set
- /// is maintained to ensure we don't visit the same PHI node multiple
- /// times.
- SmallPtrSet<const PHINode *, 16> VisitedPHIs;
-
// A prologue is generated.
bool HasPrologue = false;
Modified: llvm/trunk/lib/CodeGen/StackProtector.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/StackProtector.cpp?rev=363169&r1=363168&r2=363169&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/StackProtector.cpp (original)
+++ llvm/trunk/lib/CodeGen/StackProtector.cpp Wed Jun 12 07:23:33 2019
@@ -17,6 +17,7 @@
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
+#include "llvm/Analysis/CaptureTracking.h"
#include "llvm/Analysis/EHPersonalities.h"
#include "llvm/Analysis/OptimizationRemarkEmitter.h"
#include "llvm/CodeGen/Passes.h"
@@ -156,40 +157,6 @@ bool StackProtector::ContainsProtectable
return NeedsProtector;
}
-bool StackProtector::HasAddressTaken(const Instruction *AI) {
- for (const User *U : AI->users()) {
- if (const StoreInst *SI = dyn_cast<StoreInst>(U)) {
- if (AI == SI->getValueOperand())
- return true;
- } else if (const PtrToIntInst *SI = dyn_cast<PtrToIntInst>(U)) {
- if (AI == SI->getOperand(0))
- return true;
- } else if (const CallInst *CI = dyn_cast<CallInst>(U)) {
- // Ignore intrinsics that are not calls. TODO: Use isLoweredToCall().
- if (!isa<DbgInfoIntrinsic>(CI) && !CI->isLifetimeStartOrEnd())
- return true;
- } else if (isa<InvokeInst>(U)) {
- return true;
- } else if (const SelectInst *SI = dyn_cast<SelectInst>(U)) {
- if (HasAddressTaken(SI))
- return true;
- } else if (const PHINode *PN = dyn_cast<PHINode>(U)) {
- // Keep track of what PHI nodes we have already visited to ensure
- // they are only visited once.
- if (VisitedPHIs.insert(PN).second)
- if (HasAddressTaken(PN))
- return true;
- } else if (const GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(U)) {
- if (HasAddressTaken(GEP))
- return true;
- } else if (const BitCastInst *BI = dyn_cast<BitCastInst>(U)) {
- if (HasAddressTaken(BI))
- return true;
- }
- }
- return false;
-}
-
/// Search for the first call to the llvm.stackprotector intrinsic and return it
/// if present.
static const CallInst *findStackProtectorIntrinsic(Function &F) {
@@ -297,7 +264,9 @@ bool StackProtector::RequiresStackProtec
continue;
}
- if (Strong && HasAddressTaken(AI)) {
+ if (Strong && PointerMayBeCaptured(AI,
+ /* ReturnCaptures */ false,
+ /* StoreCaptures */ true)) {
++NumAddrTaken;
Layout.insert(std::make_pair(AI, MachineFrameInfo::SSPLK_AddrOf));
ORE.emit([&]() {
Modified: llvm/trunk/test/CodeGen/X86/stack-protector.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/stack-protector.ll?rev=363169&r1=363168&r2=363169&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/stack-protector.ll (original)
+++ llvm/trunk/test/CodeGen/X86/stack-protector.ll Wed Jun 12 07:23:33 2019
@@ -4087,8 +4087,8 @@ define i32 @IgnoreIntrinsicTest() #1 {
%1 = alloca i32, align 4
%2 = bitcast i32* %1 to i8*
call void @llvm.lifetime.start.p0i8(i64 4, i8* nonnull %2)
- store volatile i32 1, i32* %1, align 4
- %3 = load volatile i32, i32* %1, align 4
+ store i32 1, i32* %1, align 4
+ %3 = load i32, i32* %1, align 4
%4 = mul nsw i32 %3, 42
call void @llvm.lifetime.end.p0i8(i64 4, i8* nonnull %2)
ret i32 %4
Added: llvm/trunk/test/Transforms/StackProtector/X86/captures.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/StackProtector/X86/captures.ll?rev=363169&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/StackProtector/X86/captures.ll (added)
+++ llvm/trunk/test/Transforms/StackProtector/X86/captures.ll Wed Jun 12 07:23:33 2019
@@ -0,0 +1,139 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -mtriple=x86_64-pc-linux-gnu -stack-protector < %s | FileCheck %s
+; Bug 42238: Test some situations missed by old, custom capture tracking.
+
+define void @store_captures() #0 {
+; CHECK-LABEL: @store_captures(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[STACKGUARDSLOT:%.*]] = alloca i8*
+; CHECK-NEXT: [[STACKGUARD:%.*]] = load volatile i8*, i8* addrspace(257)* inttoptr (i32 40 to i8* addrspace(257)*)
+; CHECK-NEXT: call void @llvm.stackprotector(i8* [[STACKGUARD]], i8** [[STACKGUARDSLOT]])
+; CHECK-NEXT: [[RETVAL:%.*]] = alloca i32, align 4
+; CHECK-NEXT: [[A:%.*]] = alloca i32, align 4
+; CHECK-NEXT: [[J:%.*]] = alloca i32*, align 8
+; CHECK-NEXT: store i32 0, i32* [[RETVAL]]
+; CHECK-NEXT: [[LOAD:%.*]] = load i32, i32* [[A]], align 4
+; CHECK-NEXT: [[ADD:%.*]] = add nsw i32 [[LOAD]], 1
+; CHECK-NEXT: store i32 [[ADD]], i32* [[A]], align 4
+; CHECK-NEXT: store i32* [[A]], i32** [[J]], align 8
+; CHECK-NEXT: [[STACKGUARD1:%.*]] = load volatile i8*, i8* addrspace(257)* inttoptr (i32 40 to i8* addrspace(257)*)
+; CHECK-NEXT: [[TMP0:%.*]] = load volatile i8*, i8** [[STACKGUARDSLOT]]
+; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i8* [[STACKGUARD1]], [[TMP0]]
+; CHECK-NEXT: br i1 [[TMP1]], label [[SP_RETURN:%.*]], label [[CALLSTACKCHECKFAILBLK:%.*]], !prof !0
+; CHECK: SP_return:
+; CHECK-NEXT: ret void
+; CHECK: CallStackCheckFailBlk:
+; CHECK-NEXT: call void @__stack_chk_fail()
+; CHECK-NEXT: unreachable
+;
+entry:
+ %retval = alloca i32, align 4
+ %a = alloca i32, align 4
+ %j = alloca i32*, align 8
+ store i32 0, i32* %retval
+ %load = load i32, i32* %a, align 4
+ %add = add nsw i32 %load, 1
+ store i32 %add, i32* %a, align 4
+ store i32* %a, i32** %j, align 8
+ ret void
+}
+
+define i32* @return_captures() #0 {
+; CHECK-LABEL: @return_captures(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[RETVAL:%.*]] = alloca i32, align 4
+; CHECK-NEXT: [[A:%.*]] = alloca i32, align 4
+; CHECK-NEXT: [[J:%.*]] = alloca i32*, align 8
+; CHECK-NEXT: store i32 0, i32* [[RETVAL]]
+; CHECK-NEXT: [[LOAD:%.*]] = load i32, i32* [[A]], align 4
+; CHECK-NEXT: [[ADD:%.*]] = add nsw i32 [[LOAD]], 1
+; CHECK-NEXT: store i32 [[ADD]], i32* [[A]], align 4
+; CHECK-NEXT: ret i32* [[A]]
+;
+entry:
+ %retval = alloca i32, align 4
+ %a = alloca i32, align 4
+ %j = alloca i32*, align 8
+ store i32 0, i32* %retval
+ %load = load i32, i32* %a, align 4
+ %add = add nsw i32 %load, 1
+ store i32 %add, i32* %a, align 4
+ ret i32* %a
+}
+
+define void @store_addrspacecast_captures() #0 {
+; CHECK-LABEL: @store_addrspacecast_captures(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[STACKGUARDSLOT:%.*]] = alloca i8*
+; CHECK-NEXT: [[STACKGUARD:%.*]] = load volatile i8*, i8* addrspace(257)* inttoptr (i32 40 to i8* addrspace(257)*)
+; CHECK-NEXT: call void @llvm.stackprotector(i8* [[STACKGUARD]], i8** [[STACKGUARDSLOT]])
+; CHECK-NEXT: [[RETVAL:%.*]] = alloca i32, align 4
+; CHECK-NEXT: [[A:%.*]] = alloca i32, align 4
+; CHECK-NEXT: [[J:%.*]] = alloca i32 addrspace(1)*, align 8
+; CHECK-NEXT: store i32 0, i32* [[RETVAL]]
+; CHECK-NEXT: [[LOAD:%.*]] = load i32, i32* [[A]], align 4
+; CHECK-NEXT: [[ADD:%.*]] = add nsw i32 [[LOAD]], 1
+; CHECK-NEXT: store i32 [[ADD]], i32* [[A]], align 4
+; CHECK-NEXT: [[A_ADDRSPACECAST:%.*]] = addrspacecast i32* [[A]] to i32 addrspace(1)*
+; CHECK-NEXT: store i32 addrspace(1)* [[A_ADDRSPACECAST]], i32 addrspace(1)** [[J]], align 8
+; CHECK-NEXT: [[STACKGUARD1:%.*]] = load volatile i8*, i8* addrspace(257)* inttoptr (i32 40 to i8* addrspace(257)*)
+; CHECK-NEXT: [[TMP0:%.*]] = load volatile i8*, i8** [[STACKGUARDSLOT]]
+; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i8* [[STACKGUARD1]], [[TMP0]]
+; CHECK-NEXT: br i1 [[TMP1]], label [[SP_RETURN:%.*]], label [[CALLSTACKCHECKFAILBLK:%.*]], !prof !0
+; CHECK: SP_return:
+; CHECK-NEXT: ret void
+; CHECK: CallStackCheckFailBlk:
+; CHECK-NEXT: call void @__stack_chk_fail()
+; CHECK-NEXT: unreachable
+;
+entry:
+ %retval = alloca i32, align 4
+ %a = alloca i32, align 4
+ %j = alloca i32 addrspace(1)*, align 8
+ store i32 0, i32* %retval
+ %load = load i32, i32* %a, align 4
+ %add = add nsw i32 %load, 1
+ store i32 %add, i32* %a, align 4
+ %a.addrspacecast = addrspacecast i32* %a to i32 addrspace(1)*
+ store i32 addrspace(1)* %a.addrspacecast, i32 addrspace(1)** %j, align 8
+ ret void
+}
+
+define void @cmpxchg_captures() #0 {
+; CHECK-LABEL: @cmpxchg_captures(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[STACKGUARDSLOT:%.*]] = alloca i8*
+; CHECK-NEXT: [[STACKGUARD:%.*]] = load volatile i8*, i8* addrspace(257)* inttoptr (i32 40 to i8* addrspace(257)*)
+; CHECK-NEXT: call void @llvm.stackprotector(i8* [[STACKGUARD]], i8** [[STACKGUARDSLOT]])
+; CHECK-NEXT: [[RETVAL:%.*]] = alloca i32, align 4
+; CHECK-NEXT: [[A:%.*]] = alloca i32, align 4
+; CHECK-NEXT: [[J:%.*]] = alloca i32*, align 8
+; CHECK-NEXT: store i32 0, i32* [[RETVAL]]
+; CHECK-NEXT: [[LOAD:%.*]] = load i32, i32* [[A]], align 4
+; CHECK-NEXT: [[ADD:%.*]] = add nsw i32 [[LOAD]], 1
+; CHECK-NEXT: store i32 [[ADD]], i32* [[A]], align 4
+; CHECK-NEXT: [[TMP0:%.*]] = cmpxchg i32** [[J]], i32* [[A]], i32* null seq_cst monotonic
+; CHECK-NEXT: [[STACKGUARD1:%.*]] = load volatile i8*, i8* addrspace(257)* inttoptr (i32 40 to i8* addrspace(257)*)
+; CHECK-NEXT: [[TMP1:%.*]] = load volatile i8*, i8** [[STACKGUARDSLOT]]
+; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i8* [[STACKGUARD1]], [[TMP1]]
+; CHECK-NEXT: br i1 [[TMP2]], label [[SP_RETURN:%.*]], label [[CALLSTACKCHECKFAILBLK:%.*]], !prof !0
+; CHECK: SP_return:
+; CHECK-NEXT: ret void
+; CHECK: CallStackCheckFailBlk:
+; CHECK-NEXT: call void @__stack_chk_fail()
+; CHECK-NEXT: unreachable
+;
+entry:
+ %retval = alloca i32, align 4
+ %a = alloca i32, align 4
+ %j = alloca i32*, align 8
+ store i32 0, i32* %retval
+ %load = load i32, i32* %a, align 4
+ %add = add nsw i32 %load, 1
+ store i32 %add, i32* %a, align 4
+
+ cmpxchg i32** %j, i32* %a, i32* null seq_cst monotonic
+ ret void
+}
+
+attributes #0 = { sspstrong }
Added: llvm/trunk/test/Transforms/StackProtector/X86/lit.local.cfg
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/StackProtector/X86/lit.local.cfg?rev=363169&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/StackProtector/X86/lit.local.cfg (added)
+++ llvm/trunk/test/Transforms/StackProtector/X86/lit.local.cfg Wed Jun 12 07:23:33 2019
@@ -0,0 +1,3 @@
+if not 'X86' in config.root.targets:
+ config.unsupported = True
+
Modified: llvm/trunk/tools/opt/opt.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/opt/opt.cpp?rev=363169&r1=363168&r2=363169&view=diff
==============================================================================
--- llvm/trunk/tools/opt/opt.cpp (original)
+++ llvm/trunk/tools/opt/opt.cpp Wed Jun 12 07:23:33 2019
@@ -517,6 +517,7 @@ int main(int argc, char **argv) {
initializeDwarfEHPreparePass(Registry);
initializeSafeStackLegacyPassPass(Registry);
initializeSjLjEHPreparePass(Registry);
+ initializeStackProtectorPass(Registry);
initializePreISelIntrinsicLoweringLegacyPassPass(Registry);
initializeGlobalMergePass(Registry);
initializeIndirectBrExpandPassPass(Registry);
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