diff options
| -rw-r--r-- | lld/COFF/Writer.cpp | 37 | ||||
| -rw-r--r-- | lld/test/COFF/gfids-export.s | 44 |
2 files changed, 69 insertions, 12 deletions
diff --git a/lld/COFF/Writer.cpp b/lld/COFF/Writer.cpp index deb43768ddc..e5796d9bbd2 100644 --- a/lld/COFF/Writer.cpp +++ b/lld/COFF/Writer.cpp @@ -1304,6 +1304,25 @@ static void addSymbolToRVASet(SymbolRVASet &RVASet, Defined *S) { RVASet.insert({C, Off}); } +// Given a symbol, add it to the GFIDs table if it is a live, defined, function +// symbol in an executable section. +static void maybeAddAddressTakenFunction(SymbolRVASet &AddressTakenSyms, + Symbol *S) { + auto *D = dyn_cast_or_null<DefinedCOFF>(S); + + // Ignore undefined symbols and references to non-functions (e.g. globals and + // labels). + if (!D || + D->getCOFFSymbol().getComplexType() != COFF::IMAGE_SYM_DTYPE_FUNCTION) + return; + + // Mark the symbol as address taken if it's in an executable section. + Chunk *RefChunk = D->getChunk(); + OutputSection *OS = RefChunk ? RefChunk->getOutputSection() : nullptr; + if (OS && OS->Header.Characteristics & IMAGE_SCN_MEM_EXECUTE) + addSymbolToRVASet(AddressTakenSyms, D); +} + // Visit all relocations from all section contributions of this object file and // mark the relocation target as address-taken. static void markSymbolsWithRelocations(ObjFile *File, @@ -1322,17 +1341,7 @@ static void markSymbolsWithRelocations(ObjFile *File, continue; Symbol *Ref = SC->File->getSymbol(Reloc.SymbolTableIndex); - if (auto *D = dyn_cast_or_null<DefinedCOFF>(Ref)) { - if (D->getCOFFSymbol().getComplexType() != COFF::IMAGE_SYM_DTYPE_FUNCTION) - // Ignore relocations against non-functions (e.g. labels). - continue; - - // Mark the symbol if it's in an executable section. - Chunk *RefChunk = D->getChunk(); - OutputSection *OS = RefChunk ? RefChunk->getOutputSection() : nullptr; - if (OS && OS->Header.Characteristics & IMAGE_SCN_MEM_EXECUTE) - addSymbolToRVASet(UsedSymbols, D); - } + maybeAddAddressTakenFunction(UsedSymbols, Ref); } } } @@ -1359,7 +1368,11 @@ void Writer::createGuardCFTables() { // Mark the image entry as address-taken. if (Config->Entry) - addSymbolToRVASet(AddressTakenSyms, cast<Defined>(Config->Entry)); + maybeAddAddressTakenFunction(AddressTakenSyms, Config->Entry); + + // Mark exported symbols in executable sections as address-taken. + for (Export &E : Config->Exports) + maybeAddAddressTakenFunction(AddressTakenSyms, E.Sym); // Ensure sections referenced in the gfid table are 16-byte aligned. for (const ChunkAndOffset &C : AddressTakenSyms) diff --git a/lld/test/COFF/gfids-export.s b/lld/test/COFF/gfids-export.s new file mode 100644 index 00000000000..87a4f4b47fa --- /dev/null +++ b/lld/test/COFF/gfids-export.s @@ -0,0 +1,44 @@ +# REQUIRES: x86 +# RUN: llvm-mc -triple x86_64-pc-win32 %s -filetype=obj -o %t.obj +# RUN: lld-link %t.obj -guard:cf -dll -out:%t.dll -noentry +# RUN: llvm-readobj -coff-load-config %t.dll | FileCheck %s --check-prefix=CHECK + +# There should be a single entry in the table for the exported symbol. +# +# CHECK: GuardFidTable [ +# CHECK-NEXT: 0x180001000 +# CHECK-NEXT: ] + + .def func_export; .scl 2; .type 32; .endef + .globl func_export + .section .text,"xr",one_only,func_export + .p2align 4 +func_export: + movl $1, %eax + .globl label_export +label_export: + movl $2, %eax + ret + + .data + .globl data_export +data_export: + .long 42 + + .section .drectve,"dr" + .ascii " /EXPORT:func_export" + .ascii " /EXPORT:label_export" + .ascii " /EXPORT:data_export" + + +# Load configuration directory entry (winnt.h _IMAGE_LOAD_CONFIG_DIRECTORY64). +# The linker will define the __guard_* symbols. + .section .rdata,"dr" +.globl _load_config_used +_load_config_used: + .long 256 + .fill 124, 1, 0 + .quad __guard_fids_table + .quad __guard_fids_count + .long __guard_flags + .fill 128, 1, 0 |
