From eac270caf45ce957daf3c01b01a5752a818344bd Mon Sep 17 00:00:00 2001 From: Matt Morehouse Date: Tue, 11 Sep 2018 15:23:14 +0000 Subject: [PATCH] [SanitizerCoverage] Create comdat for global arrays. Summary: Place global arrays in comdat sections with their associated functions. This makes sure they are stripped along with the functions they reference, even on the BFD linker. Reviewers: eugenis Reviewed By: eugenis Subscribers: eraman, hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D51902 llvm-svn: 341951 --- .../Instrumentation/SanitizerCoverage.cpp | 45 +++++++++++++++------- .../SanitizerCoverage/div-tracing.ll | 6 +-- .../SanitizerCoverage/gep-tracing.ll | 2 +- .../SanitizerCoverage/inline-8bit-counters.ll | 2 +- .../Instrumentation/SanitizerCoverage/pc-table.ll | 2 +- .../Instrumentation/SanitizerCoverage/tracing.ll | 2 +- 6 files changed, 38 insertions(+), 21 deletions(-) diff --git a/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp b/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp index 1f97e90..11d08d4 100644 --- a/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp +++ b/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp @@ -219,6 +219,11 @@ private: MDNode::get(*C, None)); } + std::string UniqueSuffix() { + static size_t Count = 0; + return "_sancov" + std::to_string(Count++); + } + std::string getSectionName(const std::string &Section) const; std::string getSectionStart(const std::string &Section) const; std::string getSectionEnd(const std::string &Section) const; @@ -571,11 +576,34 @@ GlobalVariable *SanitizerCoverageModule::CreateFunctionLocalArrayInSection( auto Array = new GlobalVariable( *CurModule, ArrayTy, false, GlobalVariable::PrivateLinkage, Constant::getNullValue(ArrayTy), "__sancov_gen_"); - if (auto Comdat = F.getComdat()) + if (auto Comdat = F.getComdat()) { + Array->setComdat(Comdat); + } else { + // TODO: Refactor into a helper function and use it in ASan. + assert(F.hasName()); + std::string Name = F.getName(); + if (F.hasLocalLinkage()) { + std::string ModuleId = getUniqueModuleId(CurModule); + Name += ModuleId.empty() ? UniqueSuffix() : ModuleId; + } + Comdat = CurModule->getOrInsertComdat(Name); + // Make this IMAGE_COMDAT_SELECT_NODUPLICATES on COFF. Also upgrade private + // linkage to internal linkage so that a symbol table entry is emitted. This + // is necessary in order to create the comdat group. + if (TargetTriple.isOSBinFormatCOFF()) { + Comdat->setSelectionKind(Comdat::NoDuplicates); + if (F.hasPrivateLinkage()) + F.setLinkage(GlobalValue::InternalLinkage); + } + F.setComdat(Comdat); Array->setComdat(Comdat); + } Array->setSection(getSectionName(Section)); Array->setAlignment(Ty->isPointerTy() ? DL->getPointerSize() : Ty->getPrimitiveSizeInBits() / 8); + GlobalsToAppendToCompilerUsed.push_back(Array); + MDNode *MD = MDNode::get(F.getContext(), ValueAsMetadata::get(&F)); + Array->addMetadata(LLVMContext::MD_associated, *MD); return Array; } @@ -613,23 +641,12 @@ void SanitizerCoverageModule::CreateFunctionLocalArrays( FunctionGuardArray = CreateFunctionLocalArrayInSection( AllBlocks.size(), F, Int32Ty, SanCovGuardsSectionName); GlobalsToAppendToUsed.push_back(FunctionGuardArray); - GlobalsToAppendToCompilerUsed.push_back(FunctionGuardArray); - MDNode *MD = MDNode::get(F.getContext(), ValueAsMetadata::get(&F)); - FunctionGuardArray->addMetadata(LLVMContext::MD_associated, *MD); } - if (Options.Inline8bitCounters) { + if (Options.Inline8bitCounters) Function8bitCounterArray = CreateFunctionLocalArrayInSection( AllBlocks.size(), F, Int8Ty, SanCovCountersSectionName); - GlobalsToAppendToCompilerUsed.push_back(Function8bitCounterArray); - MDNode *MD = MDNode::get(F.getContext(), ValueAsMetadata::get(&F)); - Function8bitCounterArray->addMetadata(LLVMContext::MD_associated, *MD); - } - if (Options.PCTable) { + if (Options.PCTable) FunctionPCsArray = CreatePCArray(F, AllBlocks); - GlobalsToAppendToCompilerUsed.push_back(FunctionPCsArray); - MDNode *MD = MDNode::get(F.getContext(), ValueAsMetadata::get(&F)); - FunctionPCsArray->addMetadata(LLVMContext::MD_associated, *MD); - } } bool SanitizerCoverageModule::InjectCoverage(Function &F, diff --git a/llvm/test/Instrumentation/SanitizerCoverage/div-tracing.ll b/llvm/test/Instrumentation/SanitizerCoverage/div-tracing.ll index aee872c..0de2ddf 100644 --- a/llvm/test/Instrumentation/SanitizerCoverage/div-tracing.ll +++ b/llvm/test/Instrumentation/SanitizerCoverage/div-tracing.ll @@ -10,7 +10,7 @@ entry: ret i32 %div } -; CHECK-LABEL: div_a_b +; CHECK-LABEL: @div_a_b ; CHECK: call void @__sanitizer_cov_trace_div4(i32 %b) ; CHECK: ret @@ -21,7 +21,7 @@ entry: ret i32 %div } -; CHECK-LABEL: div_a_10 +; CHECK-LABEL: @div_a_10 ; CHECK-NOT: __sanitizer_cov_trace_div ; CHECK: ret @@ -31,7 +31,7 @@ entry: ret i64 %div } -; CHECK-LABEL: div_a_b +; CHECK-LABEL: @div_a_b_64 ; CHECK: call void @__sanitizer_cov_trace_div8(i64 %b) ; CHECK: ret diff --git a/llvm/test/Instrumentation/SanitizerCoverage/gep-tracing.ll b/llvm/test/Instrumentation/SanitizerCoverage/gep-tracing.ll index f305f49..ac6af4b 100644 --- a/llvm/test/Instrumentation/SanitizerCoverage/gep-tracing.ll +++ b/llvm/test/Instrumentation/SanitizerCoverage/gep-tracing.ll @@ -26,7 +26,7 @@ entry: ret void } -; CHECK-LABEL: define void @gep_2([1000 x i32]* nocapture %a, i32 %i, i32 %j) { +; CHECK-LABEL: define void @gep_2([1000 x i32]* nocapture %a, i32 %i, i32 %j) ; CHECK: call void @__sanitizer_cov_trace_gep(i64 %idxprom1) ; CHECK: call void @__sanitizer_cov_trace_gep(i64 %idxprom) ; CHECK: ret void diff --git a/llvm/test/Instrumentation/SanitizerCoverage/inline-8bit-counters.ll b/llvm/test/Instrumentation/SanitizerCoverage/inline-8bit-counters.ll index 597f77f..8814167 100644 --- a/llvm/test/Instrumentation/SanitizerCoverage/inline-8bit-counters.ll +++ b/llvm/test/Instrumentation/SanitizerCoverage/inline-8bit-counters.ll @@ -5,7 +5,7 @@ target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f3 target triple = "x86_64-unknown-linux-gnu" define void @foo() { entry: -; CHECK: section "__sancov_cntrs", align 1 +; CHECK: section "__sancov_cntrs", comdat($foo), align 1 ; CHECK: %0 = load i8, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @__sancov_gen_, i64 0, i64 0), !nosanitize ; CHECK: %1 = add i8 %0, 1 ; CHECK: store i8 %1, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @__sancov_gen_, i64 0, i64 0), !nosanitize diff --git a/llvm/test/Instrumentation/SanitizerCoverage/pc-table.ll b/llvm/test/Instrumentation/SanitizerCoverage/pc-table.ll index 7b9b2fa..888277a 100644 --- a/llvm/test/Instrumentation/SanitizerCoverage/pc-table.ll +++ b/llvm/test/Instrumentation/SanitizerCoverage/pc-table.ll @@ -17,7 +17,7 @@ entry: ret void } -; CHECK: private constant [6 x i64*] [{{.*}}@foo{{.*}}blockaddress{{.*}}blockaddress{{.*}}], section "__sancov_pcs", align 8 +; CHECK: private constant [6 x i64*] [{{.*}}@foo{{.*}}blockaddress{{.*}}blockaddress{{.*}}], section "__sancov_pcs", comdat($foo), align 8 ; CHECK: define internal void @sancov.module_ctor ; CHECK: call void @__sanitizer_cov ; CHECK: call void @__sanitizer_cov_pcs_init diff --git a/llvm/test/Instrumentation/SanitizerCoverage/tracing.ll b/llvm/test/Instrumentation/SanitizerCoverage/tracing.ll index 860904c..2982f95 100644 --- a/llvm/test/Instrumentation/SanitizerCoverage/tracing.ll +++ b/llvm/test/Instrumentation/SanitizerCoverage/tracing.ll @@ -32,7 +32,7 @@ entry: ; CHECK_PC: ret void ; CHECK_PC-NOT: call void @__sanitizer_cov_module_init -; CHECK_PC_GUARD: section "__sancov_guards", align 4 +; CHECK_PC_GUARD: section "__sancov_guards", comdat($foo), align 4 ; CHECK_PC_GUARD-LABEL: define void @foo ; CHECK_PC_GUARD: call void @__sanitizer_cov_trace_pc_guard ; CHECK_PC_GUARD: call void @__sanitizer_cov_trace_pc_guard -- 2.7.4