From cb9fb9c0eab98d653ed03d37eaa75b9a22cab355 Mon Sep 17 00:00:00 2001 From: Sean Silva Date: Tue, 14 Jun 2016 02:45:01 +0000 Subject: [PATCH] Fix for (benign) uninitialized read caught by UBSan bot. What happened here is that in the new PM there is a bunch of new copying (actually, moving) and so this reads the HasProfileData member in situations where it used to not be read. It used to only be read strictly in the "runOnFunction" method and its callees, where is *is* initialized (even after my patch). So this ends up being benign as far as functional behavior of the compiler (since we set HasProfileData in the "runImpl" method before we ever make decisions based on it). It's awesome that UBSan caught this. It highlights one more thing to watch out for when porting passes. Sanitizer bot log was: -- Testing: 17049 tests, 32 threads -- Testing: 0 .. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. FAIL: LLVM :: Transforms/JumpThreading/thread-loads.ll (15184 of 17049) ******************** TEST 'LLVM :: Transforms/JumpThreading/thread-loads.ll' FAILED ******************** Script: -- /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm_build_ubsan/./bin/opt < /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/test/Transforms/JumpThreading/thread-loads.ll -jump-threading -S | /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm_build_ubsan/./bin/FileCheck /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/test/Transforms/JumpThreading/thread-loads.ll /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm_build_ubsan/./bin/opt < /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/test/Transforms/JumpThreading/thread-loads.ll -passes=jump-threading -S | /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm_build_ubsan/./bin/FileCheck /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/test/Transforms/JumpThreading/thread-loads.ll -- Exit Code: 2 Command Output (stderr): -- /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/Transforms/Scalar/JumpThreading.h:90:57: runtime error: load of value 136, which is not a valid value for type 'bool' #0 0x2c33ba1 in llvm::JumpThreadingPass::JumpThreadingPass(llvm::JumpThreadingPass&&) /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/Transforms/Scalar/JumpThreading.h:90:57 #1 0x2bc88e4 in void llvm::PassManager::addPass(llvm::JumpThreadingPass) /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/PassManager.h:282:40 #2 0x2bb2682 in llvm::PassBuilder::parseFunctionPassName(llvm::PassManager&, llvm::StringRef) /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/Passes/PassRegistry.def:133:1 #3 0x2bb4914 in llvm::PassBuilder::parseFunctionPassPipeline(llvm::PassManager&, llvm::StringRef&, bool, bool) /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/Passes/PassBuilder.cpp:489:12 #4 0x2bb6f81 in llvm::PassBuilder::parsePassPipeline(llvm::PassManager&, llvm::StringRef, bool, bool) /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/Passes/PassBuilder.cpp:674:10 #5 0x986690 in llvm::runPassPipeline(llvm::StringRef, llvm::LLVMContext&, llvm::Module&, llvm::TargetMachine*, llvm::tool_output_file*, llvm::StringRef, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool) /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/tools/opt/NewPMDriver.cpp:85:8 #6 0x9af25e in main /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/tools/opt/opt.cpp:468:12 #7 0x7fd7e27dbf44 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21f44) #8 0x960157 in _start (/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm_build_ubsan/bin/opt+0x960157) FileCheck error: '-' is empty. FileCheck command line: /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm_build_ubsan/./bin/FileCheck /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/test/Transforms/JumpThreading/thread-loads.ll -- ******************** Testing: 0 .. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90.. Testing Time: 128.90s ******************** Failing Tests (1): LLVM :: Transforms/JumpThreading/thread-loads.ll Expected Passes : 16725 Expected Failures : 129 Unsupported Tests : 194 Unexpected Failures: 1 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272616 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Transforms/Scalar/JumpThreading.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/llvm/Transforms/Scalar/JumpThreading.h b/include/llvm/Transforms/Scalar/JumpThreading.h index a67508a2f11..e38bdd03ac0 100644 --- a/include/llvm/Transforms/Scalar/JumpThreading.h +++ b/include/llvm/Transforms/Scalar/JumpThreading.h @@ -61,7 +61,7 @@ class JumpThreadingPass : public PassInfoMixin { LazyValueInfo *LVI; std::unique_ptr BFI; std::unique_ptr BPI; - bool HasProfileData; + bool HasProfileData = false; #ifdef NDEBUG SmallPtrSet LoopHeaders; #else -- 2.50.1