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[LLD][COFF] Support CF guards on ARM64X #128440

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Merged
merged 1 commit into from
Feb 27, 2025
Merged

[LLD][COFF] Support CF guards on ARM64X #128440

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33 changes: 23 additions & 10 deletions lld/COFF/Writer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1995,10 +1995,17 @@ static void maybeAddAddressTakenFunction(SymbolRVASet &addressTakenSyms,
// Common is always data, so it is ignored.
break;
case Symbol::DefinedAbsoluteKind:
case Symbol::DefinedSyntheticKind:
// Absolute is never code, synthetic generally isn't and usually isn't
// determinable.
break;
case Symbol::DefinedSyntheticKind:
// For EC export thunks, mark both the thunk itself and its target.
if (auto expChunk = dyn_cast_or_null<ECExportThunkChunk>(
cast<Defined>(s)->getChunk())) {
addSymbolToRVASet(addressTakenSyms, cast<Defined>(s));
addSymbolToRVASet(addressTakenSyms, expChunk->target);
}
break;
case Symbol::LazyArchiveKind:
case Symbol::LazyObjectKind:
case Symbol::LazyDLLSymbolKind:
Expand Down Expand Up @@ -2063,9 +2070,11 @@ void Writer::createGuardCFTables() {
// with /guard:cf.
for (ObjFile *file : ctx.objFileInstances) {
if (file->hasGuardCF()) {
Symbol *flagSym = ctx.symtab.findUnderscore("__guard_flags");
cast<DefinedAbsolute>(flagSym)->setVA(
uint32_t(GuardFlags::CF_INSTRUMENTED));
ctx.forEachSymtab([&](SymbolTable &symtab) {
Symbol *flagSym = symtab.findUnderscore("__guard_flags");
cast<DefinedAbsolute>(flagSym)->setVA(
uint32_t(GuardFlags::CF_INSTRUMENTED));
});
break;
}
}
Expand Down Expand Up @@ -2147,8 +2156,10 @@ void Writer::createGuardCFTables() {
guardFlags |= uint32_t(GuardFlags::CF_LONGJUMP_TABLE_PRESENT);
if (config->guardCF & GuardCFLevel::EHCont)
guardFlags |= uint32_t(GuardFlags::EH_CONTINUATION_TABLE_PRESENT);
Symbol *flagSym = ctx.symtab.findUnderscore("__guard_flags");
cast<DefinedAbsolute>(flagSym)->setVA(guardFlags);
ctx.forEachSymtab([guardFlags](SymbolTable &symtab) {
Symbol *flagSym = symtab.findUnderscore("__guard_flags");
cast<DefinedAbsolute>(flagSym)->setVA(guardFlags);
});
}

// Take a list of input sections containing symbol table indices and add those
Expand Down Expand Up @@ -2219,10 +2230,12 @@ void Writer::maybeAddRVATable(SymbolRVASet tableSymbols, StringRef tableSym,
tableChunk = make<RVATableChunk>(std::move(tableSymbols));
rdataSec->addChunk(tableChunk);

Symbol *t = ctx.symtab.findUnderscore(tableSym);
Symbol *c = ctx.symtab.findUnderscore(countSym);
replaceSymbol<DefinedSynthetic>(t, t->getName(), tableChunk);
cast<DefinedAbsolute>(c)->setVA(tableChunk->getSize() / (hasFlag ? 5 : 4));
ctx.forEachSymtab([&](SymbolTable &symtab) {
Symbol *t = symtab.findUnderscore(tableSym);
Symbol *c = symtab.findUnderscore(countSym);
replaceSymbol<DefinedSynthetic>(t, t->getName(), tableChunk);
cast<DefinedAbsolute>(c)->setVA(tableChunk->getSize() / (hasFlag ? 5 : 4));
});
}

// Create CHPE metadata chunks.
Expand Down
122 changes: 122 additions & 0 deletions lld/test/COFF/arm64x-guardcf.s
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Original file line number Diff line number Diff line change
@@ -0,0 +1,122 @@
// REQUIRES: aarch64, x86
// RUN: split-file %s %t.dir && cd %t.dir

// RUN: llvm-mc -filetype=obj -triple=aarch64-windows func-gfids.s -o func-gfids-arm64.obj
// RUN: llvm-mc -filetype=obj -triple=arm64ec-windows func-gfids.s -o func-gfids-arm64ec.obj
// RUN: llvm-mc -filetype=obj -triple=aarch64-windows func-exp.s -o func-exp-arm64.obj
// RUN: llvm-mc -filetype=obj -triple=arm64ec-windows func-exp.s -o func-exp-arm64ec.obj
// RUN: llvm-mc -filetype=obj -triple=aarch64-windows dllmain.s -o dllmain-arm64.obj
// RUN: llvm-mc -filetype=obj -triple=arm64ec-windows dllmain.s -o dllmain-arm64ec.obj
// RUN: llvm-mc -filetype=obj -triple=x86_64-windows func-amd64.s -o func-amd64.obj
// RUN: llvm-mc -filetype=obj -triple=arm64ec-windows %S/Inputs/loadconfig-arm64ec.s -o loadconfig-arm64ec.obj
// RUN: llvm-mc -filetype=obj -triple=aarch64-windows %S/Inputs/loadconfig-arm64.s -o loadconfig-arm64.obj


// Check that CF guard tables contain both native and EC symbols and are referenced from both load configs.

// RUN: lld-link -dll -noentry -machine:arm64x func-gfids-arm64.obj func-gfids-arm64ec.obj func-amd64.obj -guard:cf -out:out.dll \
// RUN: loadconfig-arm64ec.obj loadconfig-arm64.obj
// RUN: llvm-readobj --coff-load-config out.dll | FileCheck --check-prefix=LOADCFG %s

// LOADCFG: LoadConfig [
// LOADCFG: GuardCFFunctionCount: 3
// LOADCFG-NEXT: GuardFlags [ (0x10500)
// LOADCFG-NEXT: CF_FUNCTION_TABLE_PRESENT (0x400)
// LOADCFG-NEXT: CF_INSTRUMENTED (0x100)
// LOADCFG-NEXT: CF_LONGJUMP_TABLE_PRESENT (0x10000)
// LOADCFG-NEXT: ]
// LOADCFG: ]
// LOADCFG: GuardFidTable [
// LOADCFG-NEXT: 0x180001000
// LOADCFG-NEXT: 0x180002000
// LOADCFG-NEXT: 0x180003000
// LOADCFG-NEXT: ]
// LOADCFG: HybridObject {
// LOADCFG: LoadConfig [
// LOADCFG: GuardCFFunctionCount: 3
// LOADCFG-NEXT: GuardFlags [ (0x10500)
// LOADCFG-NEXT: CF_FUNCTION_TABLE_PRESENT (0x400)
// LOADCFG-NEXT: CF_INSTRUMENTED (0x100)
// LOADCFG-NEXT: CF_LONGJUMP_TABLE_PRESENT (0x10000)
// LOADCFG-NEXT: ]
// LOADCFG: ]
// LOADCFG: GuardFidTable [
// LOADCFG-NEXT: 0x180001000
// LOADCFG-NEXT: 0x180002000
// LOADCFG-NEXT: 0x180003000
// LOADCFG-NEXT: ]
// LOADCFG: ]


// Check that exports from both views are present in CF guard tables.

// RUN: lld-link -dll -noentry -machine:arm64x func-exp-arm64.obj func-exp-arm64ec.obj -guard:cf -out:out-exp.dll \
// RUN: loadconfig-arm64ec.obj loadconfig-arm64.obj
// RUN: llvm-readobj --coff-load-config out-exp.dll | FileCheck --check-prefix=LOADCFG %s


// Check that entry points from both views are present in CF guard tables.

// RUN: lld-link -dll -machine:arm64x dllmain-arm64.obj dllmain-arm64ec.obj -guard:cf -out:out-entry.dll \
// RUN: loadconfig-arm64ec.obj loadconfig-arm64.obj
// RUN: llvm-readobj --coff-load-config out-entry.dll | FileCheck --check-prefix=LOADCFG %s


// Check that both load configs are marked as instrumented if any input object was built with /guard:cf.

// RUN: lld-link -dll -noentry -machine:arm64x func-gfids-arm64ec.obj -out:out-nocfg.dll \
// RUN: loadconfig-arm64ec.obj loadconfig-arm64.obj

// RUN: llvm-readobj --coff-load-config out-nocfg.dll | FileCheck --check-prefix=LOADCFG-INST %s

// LOADCFG-INST: LoadConfig [
// LOADCFG-INST: GuardFlags [ (0x100)
// LOADCFG-INST-NEXT: CF_INSTRUMENTED (0x100)
// LOADCFG-INST-NEXT: ]
// LOADCFG-INST: ]
// LOADCFG-INST: HybridObject {
// LOADCFG-INST: LoadConfig [
// LOADCFG-INST: GuardFlags [ (0x100)
// LOADCFG-INST-NEXT: CF_INSTRUMENTED (0x100)
// LOADCFG-INST-NEXT: ]
// LOADCFG-INST: ]
// LOADCFG-INST: ]

#--- func-gfids.s
.def @feat.00; .scl 3; .type 0; .endef
.globl @feat.00
@feat.00 = 0x800

.globl func
func:
ret

.section .gfids$y,"dr"
.symidx func

#--- func-amd64.s
.def @feat.00; .scl 3; .type 0; .endef
.globl @feat.00
@feat.00 = 0x800

.globl func_amd64
func_amd64:
ret

.section .gfids$y,"dr"
.symidx func_amd64

#--- func-exp.s
.def func; .scl 2; .type 32; .endef
.globl func
func:
ret

.section .drectve
.ascii "-export:func"

#--- dllmain.s
.def _DllMainCRTStartup; .scl 2; .type 32; .endef
.globl _DllMainCRTStartup
_DllMainCRTStartup:
ret