https://github.com/thurstond created https://github.com/llvm/llvm-project/pull/120464
…d-handlers) '-mllvm -ubsan-unique-traps' (https://github.com/llvm/llvm-project/pull/65972) applies to all UBSan checks. This patch introduces -fsanitize-nonmerged-handlers and -fno-sanitize-nonmerged-handlers, which allows selectively applying non-merged handlers to a subset of UBSan checks. N.B. we use "non-merged handlers" instead of "unique traps", since https://github.com/llvm/llvm-project/pull/119302 has generalized it to work for non-trap mode as well (min-rt and regular rt). This patch does not remove the -ubsan-unique-traps flag; that will override -f(no-)sanitize-non-merged-handlers. >From 2c0da9aa6f58900387fa91cdc6bcb41e0235d94c Mon Sep 17 00:00:00 2001 From: Thurston Dang <thurs...@google.com> Date: Wed, 18 Dec 2024 18:37:11 +0000 Subject: [PATCH] [ubsan] Add -fsanitize-nonmerged-handlers (and -fno-sanitize-nonmerged-handlers) '-mllvm -ubsan-unique-traps' (https://github.com/llvm/llvm-project/pull/65972) applies to all UBSan checks. This patch introduces -fsanitize-nonmerged-handlers and -fno-sanitize-nonmerged-handlers, which allows selectively applying non-merged handlers to a subset of UBSan checks. N.B. we use "non-merged handlers" instead of "unique traps", since https://github.com/llvm/llvm-project/pull/119302 has generalized it to work for non-trap mode as well (min-rt and regular rt). This patch does not remove the -ubsan-unique-traps flag; that will override -f(no-)sanitize-non-merged-handlers. --- clang/include/clang/Basic/CodeGenOptions.h | 4 ++++ clang/include/clang/Driver/Options.td | 4 ++++ clang/include/clang/Driver/SanitizerArgs.h | 1 + clang/lib/CodeGen/CGExpr.cpp | 26 +++++++++++++--------- clang/lib/CodeGen/CodeGenFunction.h | 2 +- clang/lib/Driver/SanitizerArgs.cpp | 24 +++++++++++++++++++- clang/lib/Frontend/CompilerInvocation.cpp | 6 +++++ 7 files changed, 55 insertions(+), 12 deletions(-) diff --git a/clang/include/clang/Basic/CodeGenOptions.h b/clang/include/clang/Basic/CodeGenOptions.h index 2dcf98b465661e..9b97adce42cc2a 100644 --- a/clang/include/clang/Basic/CodeGenOptions.h +++ b/clang/include/clang/Basic/CodeGenOptions.h @@ -380,6 +380,10 @@ class CodeGenOptions : public CodeGenOptionsBase { /// Set of sanitizer checks that trap rather than diagnose. SanitizerSet SanitizeTrap; + /// Set of sanitizer checks that have non-merged handlers (better + /// debuggability at the expense of code size). + SanitizerSet SanitizeNonMergedHandlers; + /// List of backend command-line options for -fembed-bitcode. std::vector<uint8_t> CmdArgs; diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index 7b544d2534d469..1a09f08890edad 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -2548,6 +2548,10 @@ def fsanitize_trap_EQ : CommaJoined<["-"], "fsanitize-trap=">, Group<f_clang_Gro def fno_sanitize_trap_EQ : CommaJoined<["-"], "fno-sanitize-trap=">, Group<f_clang_Group>, Visibility<[ClangOption, CLOption]>, HelpText<"Disable trapping for specified sanitizers">; +def fsanitize_nonmerged_handlers_EQ : CommaJoined<["-"], "fsanitize-nonmerged-handlers=">, Group<f_clang_Group>, + HelpText<"Enable non-merged handlers for specified sanitizers">; +def fno_sanitize_nonmerged_handlers_EQ : CommaJoined<["-"], "fno-sanitize-nonmerged-handlers=">, Group<f_clang_Group>, + HelpText<"Disable non-merged handlers for specified sanitizers">; def fsanitize_trap : Flag<["-"], "fsanitize-trap">, Group<f_clang_Group>, Alias<fsanitize_trap_EQ>, AliasArgs<["all"]>, HelpText<"Enable trapping for all sanitizers">; diff --git a/clang/include/clang/Driver/SanitizerArgs.h b/clang/include/clang/Driver/SanitizerArgs.h index 4f08ea2b260179..28cfe72d6a34bd 100644 --- a/clang/include/clang/Driver/SanitizerArgs.h +++ b/clang/include/clang/Driver/SanitizerArgs.h @@ -25,6 +25,7 @@ class SanitizerArgs { SanitizerSet Sanitizers; SanitizerSet RecoverableSanitizers; SanitizerSet TrapSanitizers; + SanitizerSet NonMergedHandlers; std::vector<std::string> UserIgnorelistFiles; std::vector<std::string> SystemIgnorelistFiles; diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp index 79955f55714164..9c4dfaa393966b 100644 --- a/clang/lib/CodeGen/CGExpr.cpp +++ b/clang/lib/CodeGen/CGExpr.cpp @@ -3546,7 +3546,7 @@ static void emitCheckHandlerCall(CodeGenFunction &CGF, ArrayRef<llvm::Value *> FnArgs, SanitizerHandler CheckHandler, CheckRecoverableKind RecoverKind, bool IsFatal, - llvm::BasicBlock *ContBB) { + llvm::BasicBlock *ContBB, bool NoMerge) { assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable); std::optional<ApplyDebugLocation> DL; if (!CGF.Builder.getCurrentDebugLocation()) { @@ -3581,7 +3581,7 @@ static void emitCheckHandlerCall(CodeGenFunction &CGF, llvm::AttributeList::FunctionIndex, B), /*Local=*/true); llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs); - bool NoMerge = + NoMerge = NoMerge || ClSanitizeDebugDeoptimization || !CGF.CGM.getCodeGenOpts().OptimizationLevel || (CGF.CurCodeDecl && CGF.CurCodeDecl->hasAttr<OptimizeNoneAttr>()); @@ -3608,6 +3608,7 @@ void CodeGenFunction::EmitCheck( llvm::Value *FatalCond = nullptr; llvm::Value *RecoverableCond = nullptr; llvm::Value *TrapCond = nullptr; + bool NoMerge = false; for (int i = 0, n = Checked.size(); i < n; ++i) { llvm::Value *Check = Checked[i].first; // -fsanitize-trap= overrides -fsanitize-recover=. @@ -3618,6 +3619,9 @@ void CodeGenFunction::EmitCheck( ? RecoverableCond : FatalCond; Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check; + + if (CGM.getCodeGenOpts().SanitizeNonMergedHandlers.has(Checked[i].second)) + NoMerge = true; } if (ClSanitizeGuardChecks) { @@ -3632,7 +3636,7 @@ void CodeGenFunction::EmitCheck( } if (TrapCond) - EmitTrapCheck(TrapCond, CheckHandler); + EmitTrapCheck(TrapCond, CheckHandler, NoMerge); if (!FatalCond && !RecoverableCond) return; @@ -3698,7 +3702,7 @@ void CodeGenFunction::EmitCheck( // Simple case: we need to generate a single handler call, either // fatal, or non-fatal. emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, - (FatalCond != nullptr), Cont); + (FatalCond != nullptr), Cont, NoMerge); } else { // Emit two handler calls: first one for set of unrecoverable checks, // another one for recoverable. @@ -3708,10 +3712,10 @@ void CodeGenFunction::EmitCheck( Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB); EmitBlock(FatalHandlerBB); emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true, - NonFatalHandlerBB); + NonFatalHandlerBB, NoMerge); EmitBlock(NonFatalHandlerBB); emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false, - Cont); + Cont, NoMerge); } EmitBlock(Cont); @@ -3901,7 +3905,8 @@ void CodeGenFunction::EmitUnreachable(SourceLocation Loc) { } void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked, - SanitizerHandler CheckHandlerID) { + SanitizerHandler CheckHandlerID, + bool NoMerge) { llvm::BasicBlock *Cont = createBasicBlock("cont"); // If we're optimizing, collapse all calls to trap down to just one per @@ -3911,9 +3916,10 @@ void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked, llvm::BasicBlock *&TrapBB = TrapBBs[CheckHandlerID]; - bool NoMerge = ClSanitizeDebugDeoptimization || - !CGM.getCodeGenOpts().OptimizationLevel || - (CurCodeDecl && CurCodeDecl->hasAttr<OptimizeNoneAttr>()); + NoMerge = NoMerge || + ClSanitizeDebugDeoptimization || + !CGM.getCodeGenOpts().OptimizationLevel || + (CurCodeDecl && CurCodeDecl->hasAttr<OptimizeNoneAttr>()); if (TrapBB && !NoMerge) { auto Call = TrapBB->begin(); diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h index 092d55355a0a17..c8e17b943c35f0 100644 --- a/clang/lib/CodeGen/CodeGenFunction.h +++ b/clang/lib/CodeGen/CodeGenFunction.h @@ -5166,7 +5166,7 @@ class CodeGenFunction : public CodeGenTypeCache { /// Create a basic block that will call the trap intrinsic, and emit a /// conditional branch to it, for the -ftrapv checks. - void EmitTrapCheck(llvm::Value *Checked, SanitizerHandler CheckHandlerID); + void EmitTrapCheck(llvm::Value *Checked, SanitizerHandler CheckHandlerID, bool NoMerge = false); /// Emit a call to trap or debugtrap and attach function attribute /// "trap-func-name" if specified. diff --git a/clang/lib/Driver/SanitizerArgs.cpp b/clang/lib/Driver/SanitizerArgs.cpp index 81f94f23873661..6cd8267aaef1f5 100644 --- a/clang/lib/Driver/SanitizerArgs.cpp +++ b/clang/lib/Driver/SanitizerArgs.cpp @@ -68,6 +68,9 @@ static const SanitizerMask TrappingSupported = SanitizerKind::ImplicitConversion | SanitizerKind::Nullability | SanitizerKind::LocalBounds | SanitizerKind::CFI | SanitizerKind::FloatDivideByZero | SanitizerKind::ObjCCast; +static const SanitizerMask NonMergedDefault; +static const SanitizerMask NonMergedSupported = + (SanitizerKind::Undefined & ~SanitizerKind::Vptr); static const SanitizerMask TrappingDefault = SanitizerKind::CFI; static const SanitizerMask CFIClasses = SanitizerKind::CFIVCall | SanitizerKind::CFINVCall | @@ -696,6 +699,17 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC, TrappingKinds &= Kinds; RecoverableKinds &= ~TrappingKinds; + // Parse -f(no-)?sanitize-nonmerged-handlers flags + SanitizerMask AlwaysNonMerged; // Empty + SanitizerMask NeverNonMerged = ~(setGroupBits(NonMergedSupported)); + SanitizerMask NonMergedKinds = parseSanitizeArgs( + D, Args, DiagnoseErrors, NonMergedDefault, AlwaysNonMerged, + NeverNonMerged, options::OPT_fsanitize_nonmerged_handlers_EQ, + options::OPT_fno_sanitize_nonmerged_handlers_EQ); + RecoverableKinds |= AlwaysNonMerged; + RecoverableKinds &= ~NeverNonMerged; + RecoverableKinds &= Kinds; + // Setup ignorelist files. // Add default ignorelist from resource directory for activated sanitizers, // and validate special case lists format. @@ -1113,6 +1127,8 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC, TrapSanitizers.Mask |= TrappingKinds; assert(!(RecoverableKinds & TrappingKinds) && "Overlap between recoverable and trapping sanitizers"); + + NonMergedHandlers.Mask |= NonMergedKinds; } static std::string toString(const clang::SanitizerSet &Sanitizers) { @@ -1274,6 +1290,10 @@ void SanitizerArgs::addArgs(const ToolChain &TC, const llvm::opt::ArgList &Args, CmdArgs.push_back( Args.MakeArgString("-fsanitize-trap=" + toString(TrapSanitizers))); + if (!NonMergedHandlers.empty()) + CmdArgs.push_back(Args.MakeArgString("-fsanitize-nonmerged-handlers=" + + toString(NonMergedHandlers))); + addSpecialCaseListOpt(Args, CmdArgs, "-fsanitize-ignorelist=", UserIgnorelistFiles); addSpecialCaseListOpt(Args, CmdArgs, @@ -1446,7 +1466,9 @@ SanitizerMask parseArgValues(const Driver &D, const llvm::opt::Arg *A, A->getOption().matches(options::OPT_fsanitize_recover_EQ) || A->getOption().matches(options::OPT_fno_sanitize_recover_EQ) || A->getOption().matches(options::OPT_fsanitize_trap_EQ) || - A->getOption().matches(options::OPT_fno_sanitize_trap_EQ)) && + A->getOption().matches(options::OPT_fno_sanitize_trap_EQ) || + A->getOption().matches(options::OPT_fsanitize_nonmerged_handlers_EQ) || + A->getOption().matches(options::OPT_fno_sanitize_nonmerged_handlers_EQ)) && "Invalid argument in parseArgValues!"); SanitizerMask Kinds; for (int i = 0, n = A->getNumValues(); i != n; ++i) { diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp index 298fafc21588a1..fbd736822ca085 100644 --- a/clang/lib/Frontend/CompilerInvocation.cpp +++ b/clang/lib/Frontend/CompilerInvocation.cpp @@ -1792,6 +1792,9 @@ void CompilerInvocationBase::GenerateCodeGenArgs(const CodeGenOptions &Opts, for (StringRef Sanitizer : serializeSanitizerKinds(Opts.SanitizeTrap)) GenerateArg(Consumer, OPT_fsanitize_trap_EQ, Sanitizer); + for (StringRef Sanitizer : serializeSanitizerKinds(Opts.SanitizeNonMergedHandlers)) + GenerateArg(Consumer, OPT_fsanitize_nonmerged_handlers_EQ, Sanitizer); + if (!Opts.EmitVersionIdentMetadata) GenerateArg(Consumer, OPT_Qn); @@ -2269,6 +2272,9 @@ bool CompilerInvocation::ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, parseSanitizerKinds("-fsanitize-trap=", Args.getAllArgValues(OPT_fsanitize_trap_EQ), Diags, Opts.SanitizeTrap); + parseSanitizerKinds("-fsanitize-nonmerged-handlers=", + Args.getAllArgValues(OPT_fsanitize_nonmerged_handlers_EQ), Diags, + Opts.SanitizeNonMergedHandlers); Opts.EmitVersionIdentMetadata = Args.hasFlag(OPT_Qy, OPT_Qn, true); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
