Index: clang/docs/ClangCommandLineReference.rst =================================================================== --- clang/docs/ClangCommandLineReference.rst +++ clang/docs/ClangCommandLineReference.rst @@ -3285,6 +3285,10 @@ Use the given reg for addressing the stack-protector guard +.. option:: -mstack-protector-guard-symbol= + +Use the given symbol for addressing the stack-protector guard + .. option:: -mstack-protector-guard= Use the given guard (global, tls) for addressing the stack-protector guard Index: clang/docs/ReleaseNotes.rst =================================================================== --- clang/docs/ReleaseNotes.rst +++ clang/docs/ReleaseNotes.rst @@ -538,6 +538,8 @@ - Added the ``-m[no-]rdpru`` flag to enable/disable the RDPRU instruction provided by AMD Zen2 and later processors. Defined intrinsics for using this instruction (see rdpruintrin.h). +- Support ``-mstack-protector-guard-symbol=[SymbolName]`` to use the given + symbol for addressing the stack protector guard. DWARF Support in Clang ---------------------- Index: clang/include/clang/Basic/CodeGenOptions.h =================================================================== --- clang/include/clang/Basic/CodeGenOptions.h +++ clang/include/clang/Basic/CodeGenOptions.h @@ -389,6 +389,9 @@ /// On AArch64 this can only be "sp_el0". std::string StackProtectorGuardReg; + /// Specify a symbol to be the guard value. + std::string StackProtectorGuardSymbol; + /// Path to ignorelist file specifying which objects /// (files, functions) listed for instrumentation by sanitizer /// coverage pass should actually not be instrumented. Index: clang/include/clang/Driver/Options.td =================================================================== --- clang/include/clang/Driver/Options.td +++ clang/include/clang/Driver/Options.td @@ -3771,6 +3771,9 @@ def mstack_protector_guard_offset_EQ : Joined<["-"], "mstack-protector-guard-offset=">, Group, Flags<[CC1Option]>, HelpText<"Use the given offset for addressing the stack-protector guard">, MarshallingInfoInt, "INT_MAX", "int">; +def mstack_protector_guard_symbol_EQ : Joined<["-"], "mstack-protector-guard-symbol=">, Group, Flags<[CC1Option]>, + HelpText<"Use the given symbol for addressing the stack-protector guard">, + MarshallingInfoString>; def mstack_protector_guard_reg_EQ : Joined<["-"], "mstack-protector-guard-reg=">, Group, Flags<[CC1Option]>, HelpText<"Use the given reg for addressing the stack-protector guard">, MarshallingInfoString>; Index: clang/lib/CodeGen/CodeGenModule.cpp =================================================================== --- clang/lib/CodeGen/CodeGenModule.cpp +++ clang/lib/CodeGen/CodeGenModule.cpp @@ -900,6 +900,9 @@ if (!getCodeGenOpts().StackProtectorGuardReg.empty()) getModule().setStackProtectorGuardReg( getCodeGenOpts().StackProtectorGuardReg); + if (!getCodeGenOpts().StackProtectorGuardSymbol.empty()) + getModule().setStackProtectorGuardSymbol( + getCodeGenOpts().StackProtectorGuardSymbol); if (getCodeGenOpts().StackProtectorGuardOffset != INT_MAX) getModule().setStackProtectorGuardOffset( getCodeGenOpts().StackProtectorGuardOffset); Index: clang/lib/Driver/ToolChains/Clang.cpp =================================================================== --- clang/lib/Driver/ToolChains/Clang.cpp +++ clang/lib/Driver/ToolChains/Clang.cpp @@ -3231,6 +3231,16 @@ Args.AddAllArgValues(CmdArgs, options::OPT_Xanalyzer); } +static bool isValidSymbolName(StringRef S) { + if (S.empty()) + return false; + + if (std::isdigit(S[0])) + return false; + + return llvm::all_of(S, [](char C) { return std::isalnum(C) || C == '_'; }); +} + static void RenderSSPOptions(const Driver &D, const ToolChain &TC, const ArgList &Args, ArgStringList &CmdArgs, bool KernelOrKext) { @@ -3362,6 +3372,16 @@ } A->render(Args, CmdArgs); } + + if (Arg *A = Args.getLastArg(options::OPT_mstack_protector_guard_symbol_EQ)) { + StringRef Value = A->getValue(); + if (!isValidSymbolName(Value)) { + D.Diag(diag::err_drv_argument_only_allowed_with) + << A->getOption().getName() << "legal symbol name"; + return; + } + A->render(Args, CmdArgs); + } } static void RenderSCPOptions(const ToolChain &TC, const ArgList &Args, Index: clang/test/Driver/stack-protector-guard.c =================================================================== --- clang/test/Driver/stack-protector-guard.c +++ clang/test/Driver/stack-protector-guard.c @@ -13,6 +13,8 @@ // RUN: FileCheck -check-prefix=CHECK-FS %s // RUN: %clang -### -target x86_64-unknown-unknown -mstack-protector-guard-reg=gs %s 2>&1 | \ // RUN: FileCheck -check-prefix=CHECK-GS %s +// RUN: %clang -### -target x86_64-unknown-unknown -mstack-protector-guard-symbol=sym %s 2>&1 | \ +// RUN: FileCheck -check-prefix=CHECK-SYM %s // Invalid arch // RUN: not %clang -target powerpc64le-linux-gnu -mstack-protector-guard=tls %s 2>&1 | \ @@ -32,10 +34,16 @@ // RUN: FileCheck -check-prefix=INVALID-REG %s // RUN: not %clang -target x86_64-unknown-unknown -c -mstack-protector-guard-reg=ds %s 2>&1 | \ // RUN: FileCheck -check-prefix=INVALID-REG %s +// RUN: not %clang -target x86_64-unknown-unknown -c -mstack-protector-guard-symbol=2s %s 2>&1 | \ +// RUN: FileCheck -check-prefix=INVALID-SYM %s +// RUN: not %clang -target x86_64-unknown-unknown -c -mstack-protector-guard-symbol= %s 2>&1 | \ +// RUN: FileCheck -check-prefix=INVALID-SYM %s // CHECK-FS: "-cc1" {{.*}}"-mstack-protector-guard-reg=fs" // CHECK-GS: "-cc1" {{.*}}"-mstack-protector-guard-reg=gs" // INVALID-REG: error: invalid value {{.*}} in 'mstack-protector-guard-reg=', expected one of: fs gs +// CHECK-SYM: "-cc1" {{.*}}"-mstack-protector-guard-symbol=sym" +// INVALID-SYM: error: invalid value {{.*}} in 'mstack-protector-guard-symbol=' only allowed with 'legal symbol name' // RUN: not %clang -target arm-eabi-c -mstack-protector-guard=tls %s 2>&1 | \ // RUN: FileCheck -check-prefix=MISSING-OFFSET %s Index: llvm/docs/ReleaseNotes.rst =================================================================== --- llvm/docs/ReleaseNotes.rst +++ llvm/docs/ReleaseNotes.rst @@ -215,6 +215,12 @@ --------------------------------- +Changes to the Metadata Info +--------------------------------- + +* Add Module Flags Metadata ``stack-protector-guard-symbol`` which specify a + symbol for addressing the stack-protector guard. + Changes to the Debug Info --------------------------------- Index: llvm/include/llvm/IR/Module.h =================================================================== --- llvm/include/llvm/IR/Module.h +++ llvm/include/llvm/IR/Module.h @@ -911,6 +911,10 @@ StringRef getStackProtectorGuardReg() const; void setStackProtectorGuardReg(StringRef Reg); + /// Get/set a symbol to use as the stack protector guard. + StringRef getStackProtectorGuardSymbol() const; + void setStackProtectorGuardSymbol(StringRef Symbol); + /// Get/set what offset from the stack protector to use. int getStackProtectorGuardOffset() const; void setStackProtectorGuardOffset(int Offset); Index: llvm/lib/IR/Module.cpp =================================================================== --- llvm/lib/IR/Module.cpp +++ llvm/lib/IR/Module.cpp @@ -714,6 +714,18 @@ addModuleFlag(ModFlagBehavior::Error, "stack-protector-guard-reg", ID); } +StringRef Module::getStackProtectorGuardSymbol() const { + Metadata *MD = getModuleFlag("stack-protector-guard-symbol"); + if (auto *MDS = dyn_cast_or_null(MD)) + return MDS->getString(); + return {}; +} + +void Module::setStackProtectorGuardSymbol(StringRef Symbol) { + MDString *ID = MDString::get(getContext(), Symbol); + addModuleFlag(ModFlagBehavior::Error, "stack-protector-guard-symbol", ID); +} + int Module::getStackProtectorGuardOffset() const { Metadata *MD = getModuleFlag("stack-protector-guard-offset"); if (auto *CI = mdconst::dyn_extract_or_null(MD)) Index: llvm/lib/Target/X86/X86ISelLowering.cpp =================================================================== --- llvm/lib/Target/X86/X86ISelLowering.cpp +++ llvm/lib/Target/X86/X86ISelLowering.cpp @@ -2817,6 +2817,21 @@ AddressSpace = X86AS::FS; else if (GuardReg == "gs") AddressSpace = X86AS::GS; + + // Use symbol guard if user specify. + StringRef GuardSymb = M->getStackProtectorGuardSymbol(); + if (!GuardSymb.empty()) { + GlobalVariable *GV = M->getGlobalVariable(GuardSymb); + if (!GV) { + Type *Ty = Subtarget.is64Bit() ? Type::getInt64Ty(M->getContext()) + : Type::getInt32Ty(M->getContext()); + GV = new GlobalVariable(*M, Ty, false, GlobalValue::ExternalLinkage, + nullptr, GuardSymb, nullptr, + GlobalValue::NotThreadLocal, AddressSpace); + } + return GV; + } + return SegmentOffset(IRB, Offset, AddressSpace); } } Index: llvm/test/CodeGen/X86/stack-protector-3.ll =================================================================== --- llvm/test/CodeGen/X86/stack-protector-3.ll +++ llvm/test/CodeGen/X86/stack-protector-3.ll @@ -6,6 +6,8 @@ ; RUN: cat %t/main.ll %t/e.ll > %t/e2.ll ; RUN: cat %t/main.ll %t/f.ll > %t/f2.ll ; RUN: cat %t/main.ll %t/g.ll > %t/g2.ll +; RUN: cat %t/main.ll %t/h.ll > %t/h2.ll +; RUN: cat %t/existedGV.ll %t/main.ll %t/h.ll > %t/i2.ll ; RUN: llc -mtriple=x86_64-pc-linux-gnu -o - < %t/a2.ll | FileCheck --check-prefix=CHECK-TLS-FS-40 %s ; RUN: llc -mtriple=x86_64-pc-linux-gnu -o - < %t/b2.ll | FileCheck --check-prefix=CHECK-TLS-FS-40 %s ; RUN: llc -mtriple=x86_64-pc-linux-gnu -o - < %t/c2.ll | FileCheck --check-prefix=CHECK-GLOBAL %s @@ -13,8 +15,8 @@ ; RUN: llc -mtriple=x86_64-pc-linux-gnu -o - < %t/e2.ll | FileCheck --check-prefix=CHECK-GS %s ; RUN: llc -mtriple=x86_64-pc-linux-gnu -o - < %t/f2.ll | FileCheck --check-prefix=CHECK-OFFSET %s ; RUN: llc -mtriple=x86_64-pc-linux-gnu -o - < %t/g2.ll | FileCheck --check-prefix=CHECK-NEGATIVE-OFFSET %s - -;--- main.ll +; RUN: llc -mtriple=x86_64-pc-linux-gnu -o - < %t/h2.ll | FileCheck --check-prefix=CHECK-SYM %s +; RUN: llc -mtriple=x86_64-pc-linux-gnu -o - < %t/i2.ll | FileCheck --check-prefix=CHECK-SYMGV %s ; CHECK-TLS-FS-40: movq %fs:40, %rax ; CHECK-TLS-FS-40: movq %fs:40, %rax @@ -57,7 +59,31 @@ ; CHECK-GLOBAL-NEXT: .cfi_def_cfa_offset 32 ; CHECK-GLOBAL-NEXT: callq __stack_chk_fail +; CHECK-SYM: movq __woof@GOTPCREL(%rip), %rax +; CHECK-SYM-NEXT: movq %fs:(%rax), %rcx +; CHECK-SYM-NEXT: movq %rcx, 16(%rsp) +; CHECK-SYM: movq %fs:(%rax), %rax +; CHECK-SYM-NEXT: cmpq 16(%rsp), %rax +; CHECK-SYM-NEXT: jne .LBB0_2 +; CHECK-SYM: .LBB0_2: +; CHECK-SYM-NEXT: .cfi_def_cfa_offset 32 +; CHECK-SYM-NEXT: callq __stack_chk_fai + +; CHECK-SYMGV: movq __woof(%rip), %rax +; CHECK-SYMGV-NEXT: movq %rax, 16(%rsp) +; CHECK-SYMGV: cmpq 16(%rsp), %rax +; CHECK-SYMGV-NEXT: jne .LBB0_2 +; CHECK-SYMGV: .LBB0_2: +; CHECK-SYMGV-NEXT: .cfi_def_cfa_offset 32 +; CHECK-SYMGV-NEXT: callq __stack_chk_fail + ; ModuleID = 't.c' +;--- existedGV.ll + +@__woof = dso_local local_unnamed_addr global ptr null, align 8 + +;--- main.ll + @.str = private unnamed_addr constant [14 x i8] c"stackoverflow\00", align 1 @a = dso_local local_unnamed_addr global ptr null, align 8 @@ -104,3 +130,6 @@ ;--- g.ll !llvm.module.flags = !{!1} !1 = !{i32 2, !"stack-protector-guard-offset", i32 -20} +;--- h.ll +!llvm.module.flags = !{!1} +!1 = !{i32 2, !"stack-protector-guard-symbol", !"__woof"}