From b2d259060d121ba22db18797d230a10c6a95ef62 Mon Sep 17 00:00:00 2001 From: Alexey Samsonov Date: Sat, 12 Jul 2014 00:42:52 +0000 Subject: [PATCH] [ASan] Collect unmangled names of global variables in Clang to print them in error reports. Currently ASan instrumentation pass creates a string with global name for each instrumented global (to include global names in the error report). Global name is already mangled at this point, and we may not be able to demangle it at runtime (e.g. there is no __cxa_demangle on Android). Instead, create a string with fully qualified global name in Clang, and pass it to ASan instrumentation pass in llvm.asan.globals metadata. If there is no metadata for some global, ASan will use the original algorithm. This fixes https://code.google.com/p/address-sanitizer/issues/detail?id=264. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212872 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../Instrumentation/AddressSanitizer.cpp | 29 +++++++++++++++------- .../AddressSanitizer/global_metadata.ll | 20 ++++++++++----- .../AddressSanitizer/instrument_global.ll | 2 +- .../instrument_initializer_metadata.ll | 8 +++--- 4 files changed, 39 insertions(+), 20 deletions(-) diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp index 17cfd92ff27..e42839c9c6b 100644 --- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp +++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp @@ -216,8 +216,11 @@ namespace { class GlobalsMetadata { public: struct Entry { - Entry() : SourceLoc(nullptr), IsDynInit(false), IsBlacklisted(false) {} + Entry() + : SourceLoc(nullptr), Name(nullptr), IsDynInit(false), + IsBlacklisted(false) {} GlobalVariable *SourceLoc; + GlobalVariable *Name; bool IsDynInit; bool IsBlacklisted; }; @@ -232,7 +235,7 @@ class GlobalsMetadata { return; for (auto MDN : Globals->operands()) { // Metadata node contains the global and the fields of "Entry". - assert(MDN->getNumOperands() == 4); + assert(MDN->getNumOperands() == 5); Value *V = MDN->getOperand(0); // The optimizer may optimize away a global entirely. if (!V) @@ -246,9 +249,14 @@ class GlobalsMetadata { E.SourceLoc = GVLoc; addSourceLocationGlobal(GVLoc); } - ConstantInt *IsDynInit = cast(MDN->getOperand(2)); + if (Value *Name = MDN->getOperand(2)) { + GlobalVariable *GVName = cast(Name); + E.Name = GVName; + InstrumentationGlobals.insert(GVName); + } + ConstantInt *IsDynInit = cast(MDN->getOperand(3)); E.IsDynInit |= IsDynInit->isOne(); - ConstantInt *IsBlacklisted = cast(MDN->getOperand(3)); + ConstantInt *IsBlacklisted = cast(MDN->getOperand(4)); E.IsBlacklisted |= IsBlacklisted->isOne(); } } @@ -1049,6 +1057,14 @@ bool AddressSanitizerModule::InstrumentGlobals(IRBuilder<> &IRB, Module &M) { for (size_t i = 0; i < n; i++) { static const uint64_t kMaxGlobalRedzone = 1 << 18; GlobalVariable *G = GlobalsToChange[i]; + + auto MD = GlobalsMD.get(G); + // Create string holding the global name unless it was provided by + // the metadata. + GlobalVariable *Name = + MD.Name ? MD.Name : createPrivateGlobalForString(M, G->getName(), + /*AllowMerging*/ true); + PointerType *PtrTy = cast(G->getType()); Type *Ty = PtrTy->getElementType(); uint64_t SizeInBytes = DL->getTypeAllocSize(Ty); @@ -1070,9 +1086,6 @@ bool AddressSanitizerModule::InstrumentGlobals(IRBuilder<> &IRB, Module &M) { NewTy, G->getInitializer(), Constant::getNullValue(RightRedZoneTy), NULL); - GlobalVariable *Name = - createPrivateGlobalForString(M, G->getName(), /*AllowMerging*/true); - // Create a new global variable with enough space for a redzone. GlobalValue::LinkageTypes Linkage = G->getLinkage(); if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage) @@ -1092,8 +1105,6 @@ bool AddressSanitizerModule::InstrumentGlobals(IRBuilder<> &IRB, Module &M) { NewGlobal->takeName(G); G->eraseFromParent(); - auto MD = GlobalsMD.get(G); - Initializers[i] = ConstantStruct::get( GlobalStructTy, ConstantExpr::getPointerCast(NewGlobal, IntptrTy), ConstantInt::get(IntptrTy, SizeInBytes), diff --git a/test/Instrumentation/AddressSanitizer/global_metadata.ll b/test/Instrumentation/AddressSanitizer/global_metadata.ll index 9641c3ed4d7..4dcd53b3ad8 100644 --- a/test/Instrumentation/AddressSanitizer/global_metadata.ll +++ b/test/Instrumentation/AddressSanitizer/global_metadata.ll @@ -18,12 +18,20 @@ target triple = "x86_64-unknown-linux-gnu" @.asan_loc_descr2 = private unnamed_addr constant { [22 x i8]*, i32, i32 } { [22 x i8]* @.str1, i32 12, i32 14 } @.asan_loc_descr4 = private unnamed_addr constant { [22 x i8]*, i32, i32 } { [22 x i8]* @.str1, i32 14, i32 25 } +; Global names: +@.str2 = private unnamed_addr constant [7 x i8] c"global\00", align 1 +@.str3 = private unnamed_addr constant [16 x i8] c"dyn_init_global\00", align 1 +@.str4 = private unnamed_addr constant [11 x i8] c"static_var\00", align 1 +@.str5 = private unnamed_addr constant [17 x i8] c"\00", align 1 + ; Check that globals were instrumented, but sanitizer location descriptors weren't: ; CHECK: @global = global { i32, [60 x i8] } zeroinitializer, align 32 ; CHECK: @.str = internal unnamed_addr constant { [14 x i8], [50 x i8] } { [14 x i8] c"Hello, world!\00", [50 x i8] zeroinitializer }, align 32 ; CHECK: @.asan_loc_descr = private unnamed_addr constant { [22 x i8]*, i32, i32 } { [22 x i8]* @.str1, i32 5, i32 5 } +; CHECK: @.str2 = private unnamed_addr constant [7 x i8] c"global\00", align 1 -; Check that location decriptors were passed into __asan_register_globals: +; Check that location decriptors and global names were passed into __asan_register_globals: +; CHECK: i64 ptrtoint ([7 x i8]* @.str2 to i64) ; CHECK: i64 ptrtoint ({ [22 x i8]*, i32, i32 }* @.asan_loc_descr to i64) ; Function Attrs: nounwind sanitize_address @@ -55,9 +63,9 @@ attributes #1 = { nounwind sanitize_address "less-precise-fpmad"="false" "no-fra !llvm.asan.globals = !{!0, !1, !2, !3, !4} !llvm.ident = !{!5} -!0 = metadata !{i32* @global, { [22 x i8]*, i32, i32 }* @.asan_loc_descr, i1 false, i1 false} -!1 = metadata !{i32* @dyn_init_global, { [22 x i8]*, i32, i32 }* @.asan_loc_descr1, i1 true, i1 false} -!2 = metadata !{i32* @blacklisted_global, null, i1 false, i1 true} -!3 = metadata !{i32* @_ZZ4funcvE10static_var, { [22 x i8]*, i32, i32 }* @.asan_loc_descr2, i1 false, i1 false} -!4 = metadata !{[14 x i8]* @.str, { [22 x i8]*, i32, i32 }* @.asan_loc_descr4, i1 false, i1 false} +!0 = metadata !{i32* @global, { [22 x i8]*, i32, i32 }* @.asan_loc_descr, [7 x i8]* @.str2, i1 false, i1 false} +!1 = metadata !{i32* @dyn_init_global, { [22 x i8]*, i32, i32 }* @.asan_loc_descr1, [16 x i8]* @.str3, i1 true, i1 false} +!2 = metadata !{i32* @blacklisted_global, null, null, i1 false, i1 true} +!3 = metadata !{i32* @_ZZ4funcvE10static_var, { [22 x i8]*, i32, i32 }* @.asan_loc_descr2, [11 x i8]* @.str4, i1 false, i1 false} +!4 = metadata !{[14 x i8]* @.str, { [22 x i8]*, i32, i32 }* @.asan_loc_descr4, [17 x i8]* @.str5, i1 false, i1 false} !5 = metadata !{metadata !"clang version 3.5.0 (211282)"} diff --git a/test/Instrumentation/AddressSanitizer/instrument_global.ll b/test/Instrumentation/AddressSanitizer/instrument_global.ll index 816ab291566..80791d9a905 100644 --- a/test/Instrumentation/AddressSanitizer/instrument_global.ll +++ b/test/Instrumentation/AddressSanitizer/instrument_global.ll @@ -69,7 +69,7 @@ entry: !llvm.asan.globals = !{!0} -!0 = metadata !{[10 x i32]* @GlobDy, null, i1 true, i1 false} +!0 = metadata !{[10 x i32]* @GlobDy, null, null, i1 true, i1 false} ; CHECK-LABEL: define internal void @asan.module_ctor ; CHECK-NOT: ret diff --git a/test/Instrumentation/AddressSanitizer/instrument_initializer_metadata.ll b/test/Instrumentation/AddressSanitizer/instrument_initializer_metadata.ll index 83ff53f6f51..c119879351a 100644 --- a/test/Instrumentation/AddressSanitizer/instrument_initializer_metadata.ll +++ b/test/Instrumentation/AddressSanitizer/instrument_initializer_metadata.ll @@ -7,10 +7,10 @@ target triple = "x86_64-unknown-linux-gnu" @YYY = global i32 0, align 4 ; W/o dynamic initializer. ; Clang will emit the following metadata identifying @xxx as dynamically ; initialized. -!0 = metadata !{i32* @xxx, null, i1 true, i1 false} -!1 = metadata !{i32* @XXX, null, i1 true, i1 false} -!2 = metadata !{i32* @yyy, null, i1 false, i1 false} -!3 = metadata !{i32* @YYY, null, i1 false, i1 false} +!0 = metadata !{i32* @xxx, null, null, i1 true, i1 false} +!1 = metadata !{i32* @XXX, null, null, i1 true, i1 false} +!2 = metadata !{i32* @yyy, null, null, i1 false, i1 false} +!3 = metadata !{i32* @YYY, null, null, i1 false, i1 false} !llvm.asan.globals = !{!0, !1, !2, !3} define i32 @initializer() uwtable { -- 2.11.0