Author: jfb Date: Tue Jan 13 19:07:51 2015 New Revision: 225910 URL: http://llvm.org/viewvc/llvm-project?rev=225910&view=rev Log: Insert random noops to increase security against ROP attacks (clang)
A pass that adds random noops to X86 binaries to introduce diversity with the goal of increasing security against most return-oriented programming attacks. Command line options: -noop-insertion // Enable noop insertion. -noop-insertion-percentage=X // X% of assembly instructions will have a noop prepended (default: 50%, requires -noop-insertion) -max-noops-per-instruction=X // Randomly generate X noops per instruction. ie. roll the dice X times with probability set above (default: 1). This doesn't guarantee X noop instructions. In addition, the following 'quick switch' in clang enables basic diversity using default settings (currently: noop insertion and schedule randomization; it is intended to be extended in the future). -fdiversify This is the clang part of the patch. llvm part: D3392 http://reviews.llvm.org/D3393 Patch by Stephen Crane (@rinon) Modified: cfe/trunk/include/clang/Driver/CC1Options.td cfe/trunk/include/clang/Driver/Options.td cfe/trunk/include/clang/Frontend/CodeGenOptions.def cfe/trunk/lib/CodeGen/BackendUtil.cpp cfe/trunk/lib/Driver/Tools.cpp cfe/trunk/lib/Frontend/CompilerInvocation.cpp Modified: cfe/trunk/include/clang/Driver/CC1Options.td URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/CC1Options.td?rev=225910&r1=225909&r2=225910&view=diff ============================================================================== --- cfe/trunk/include/clang/Driver/CC1Options.td (original) +++ cfe/trunk/include/clang/Driver/CC1Options.td Tue Jan 13 19:07:51 2015 @@ -194,6 +194,8 @@ def relaxed_aliasing : Flag<["-"], "rela HelpText<"Turn off Type Based Alias Analysis">; def no_struct_path_tbaa : Flag<["-"], "no-struct-path-tbaa">, HelpText<"Turn off struct-path aware Type Based Alias Analysis">; +def noop_insertion : Flag<["-"], "noop-insertion">, + HelpText<"Randomly insert NOOPs">; def masm_verbose : Flag<["-"], "masm-verbose">, HelpText<"Generate verbose assembly output">; def mcode_model : Separate<["-"], "mcode-model">, Modified: cfe/trunk/include/clang/Driver/Options.td URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/Options.td?rev=225910&r1=225909&r2=225910&view=diff ============================================================================== --- cfe/trunk/include/clang/Driver/Options.td (original) +++ cfe/trunk/include/clang/Driver/Options.td Tue Jan 13 19:07:51 2015 @@ -469,6 +469,7 @@ def fdiagnostics_show_category_EQ : Join def fdiagnostics_show_template_tree : Flag<["-"], "fdiagnostics-show-template-tree">, Group<f_Group>, Flags<[CC1Option]>, HelpText<"Print a template comparison tree for differing templates">; +def fdiversify : Flag<["-"], "fdiversify">, Group<f_clang_Group>; def fdollars_in_identifiers : Flag<["-"], "fdollars-in-identifiers">, Group<f_Group>, HelpText<"Allow '$' in identifiers">, Flags<[CC1Option]>; def fdwarf2_cfi_asm : Flag<["-"], "fdwarf2-cfi-asm">, Group<clang_ignored_f_Group>; @@ -857,7 +858,7 @@ def fprofile_arcs : Flag<["-"], "fprofil def fno_profile_arcs : Flag<["-"], "fno-profile-arcs">, Group<f_Group>; def fprofile_generate : Flag<["-"], "fprofile-generate">, Group<f_Group>; def framework : Separate<["-"], "framework">, Flags<[LinkerInput]>; -def frandom_seed_EQ : Joined<["-"], "frandom-seed=">, Group<clang_ignored_f_Group>; +def frandom_seed_EQ : Joined<["-"], "frandom-seed=">, Group<f_Group>, Flags<[CC1Option]>; def freg_struct_return : Flag<["-"], "freg-struct-return">, Group<f_Group>, Flags<[CC1Option]>, HelpText<"Override the default ABI to return small structs in registers">; def frtti : Flag<["-"], "frtti">, Group<f_Group>; Modified: cfe/trunk/include/clang/Frontend/CodeGenOptions.def URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Frontend/CodeGenOptions.def?rev=225910&r1=225909&r2=225910&view=diff ============================================================================== --- cfe/trunk/include/clang/Frontend/CodeGenOptions.def (original) +++ cfe/trunk/include/clang/Frontend/CodeGenOptions.def Tue Jan 13 19:07:51 2015 @@ -160,6 +160,8 @@ ENUM_CODEGENOPT(Inlining, InliningMethod /// The default TLS model to use. ENUM_CODEGENOPT(DefaultTLSModel, TLSModel, 2, GeneralDynamicTLSModel) +CODEGENOPT(NoopInsertion, 1, 0) ///< Randomly add NOPs + #undef CODEGENOPT #undef ENUM_CODEGENOPT #undef VALUE_CODEGENOPT Modified: cfe/trunk/lib/CodeGen/BackendUtil.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/BackendUtil.cpp?rev=225910&r1=225909&r2=225910&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/BackendUtil.cpp (original) +++ cfe/trunk/lib/CodeGen/BackendUtil.cpp Tue Jan 13 19:07:51 2015 @@ -519,6 +519,7 @@ TargetMachine *EmitAssemblyHelper::Creat Options.PositionIndependentExecutable = LangOpts.PIELevel != 0; Options.FunctionSections = CodeGenOpts.FunctionSections; Options.DataSections = CodeGenOpts.DataSections; + Options.NoopInsertion = CodeGenOpts.NoopInsertion; Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll; Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels; Modified: cfe/trunk/lib/Driver/Tools.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=225910&r1=225909&r2=225910&view=diff ============================================================================== --- cfe/trunk/lib/Driver/Tools.cpp (original) +++ cfe/trunk/lib/Driver/Tools.cpp Tue Jan 13 19:07:51 2015 @@ -3737,6 +3737,17 @@ void Clang::ConstructJob(Compilation &C, getToolChain().getTriple().getArch() == llvm::Triple::aarch64_be) CmdArgs.push_back("-fallow-half-arguments-and-returns"); + // Translate -frandom-seed to seed the LLVM RNG + if (Args.hasArg(options::OPT_frandom_seed_EQ)) { + StringRef seed = Args.getLastArgValue(options::OPT_frandom_seed_EQ); + CmdArgs.push_back("-backend-option"); + CmdArgs.push_back(Args.MakeArgString("-rng-seed=" + seed)); + } + + if (Args.hasArg(options::OPT_fdiversify)) { + CmdArgs.push_back("-noop-insertion"); + } + if (Arg *A = Args.getLastArg(options::OPT_mrestrict_it, options::OPT_mno_restrict_it)) { if (A->getOption().matches(options::OPT_mrestrict_it)) { Modified: cfe/trunk/lib/Frontend/CompilerInvocation.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/CompilerInvocation.cpp?rev=225910&r1=225909&r2=225910&view=diff ============================================================================== --- cfe/trunk/lib/Frontend/CompilerInvocation.cpp (original) +++ cfe/trunk/lib/Frontend/CompilerInvocation.cpp Tue Jan 13 19:07:51 2015 @@ -516,6 +516,7 @@ static bool ParseCodeGenArgs(CodeGenOpti Opts.SSPBufferSize = getLastArgIntValue(Args, OPT_stack_protector_buffer_size, 8, Diags); Opts.StackRealignment = Args.hasArg(OPT_mstackrealign); + Opts.NoopInsertion = Args.hasArg(OPT_noop_insertion); if (Arg *A = Args.getLastArg(OPT_mstack_alignment)) { StringRef Val = A->getValue(); unsigned StackAlignment = Opts.StackAlignment; _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
