diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/go/go_test.go | 33 | ||||
| -rw-r--r-- | src/cmd/link/internal/ld/lib.go | 3 | ||||
| -rw-r--r-- | src/runtime/cgo/gcc_windows_386.c | 1 | ||||
| -rw-r--r-- | src/runtime/cgo/gcc_windows_amd64.c | 1 | ||||
| -rw-r--r-- | src/runtime/cgo/libcgo_windows.h | 12 |
5 files changed, 47 insertions, 3 deletions
diff --git a/src/cmd/go/go_test.go b/src/cmd/go/go_test.go index 1fb1325519..7bbadd3974 100644 --- a/src/cmd/go/go_test.go +++ b/src/cmd/go/go_test.go @@ -9,6 +9,7 @@ import ( "debug/elf" "debug/macho" "debug/pe" + "encoding/binary" "flag" "fmt" "go/format" @@ -2129,6 +2130,38 @@ func testBuildmodePIE(t *testing.T, useCgo, setBuildmodeToPIE bool) { if (dc & pe.IMAGE_DLLCHARACTERISTICS_DYNAMIC_BASE) == 0 { t.Error("IMAGE_DLLCHARACTERISTICS_DYNAMIC_BASE flag is not set") } + if useCgo { + // Test that only one symbol is exported (#40795). + // PIE binaries don´t require .edata section but unfortunately + // binutils doesn´t generate a .reloc section unless there is + // at least one symbol exported. + // See https://sourceware.org/bugzilla/show_bug.cgi?id=19011 + section := f.Section(".edata") + if section == nil { + t.Fatalf(".edata section is not present") + } + // TODO: deduplicate this struct from cmd/link/internal/ld/pe.go + type IMAGE_EXPORT_DIRECTORY struct { + _ [2]uint32 + _ [2]uint16 + _ [2]uint32 + NumberOfFunctions uint32 + NumberOfNames uint32 + _ [3]uint32 + } + var e IMAGE_EXPORT_DIRECTORY + if err := binary.Read(section.Open(), binary.LittleEndian, &e); err != nil { + t.Fatalf("binary.Read failed: %v", err) + } + + // Only _cgo_dummy_export should be exported + if e.NumberOfFunctions != 1 { + t.Fatalf("got %d exported functions; want 1", e.NumberOfFunctions) + } + if e.NumberOfNames != 1 { + t.Fatalf("got %d exported names; want 1", e.NumberOfNames) + } + } default: panic("unreachable") } diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go index 73e0b35bc0..735b84d37d 100644 --- a/src/cmd/link/internal/ld/lib.go +++ b/src/cmd/link/internal/ld/lib.go @@ -1320,9 +1320,6 @@ func (ctxt *Link) hostlink() { case objabi.Hdarwin, objabi.Haix: case objabi.Hwindows: argv = addASLRargs(argv) - // Work around binutils limitation that strips relocation table for dynamicbase. - // See https://sourceware.org/bugzilla/show_bug.cgi?id=19011 - argv = append(argv, "-Wl,--export-all-symbols") default: // ELF. if ctxt.UseRelro() { diff --git a/src/runtime/cgo/gcc_windows_386.c b/src/runtime/cgo/gcc_windows_386.c index 9184b91393..60cb011bf2 100644 --- a/src/runtime/cgo/gcc_windows_386.c +++ b/src/runtime/cgo/gcc_windows_386.c @@ -9,6 +9,7 @@ #include <stdio.h> #include <errno.h> #include "libcgo.h" +#include "libcgo_windows.h" static void threadentry(void*); diff --git a/src/runtime/cgo/gcc_windows_amd64.c b/src/runtime/cgo/gcc_windows_amd64.c index 7192a24631..0f8c817f0e 100644 --- a/src/runtime/cgo/gcc_windows_amd64.c +++ b/src/runtime/cgo/gcc_windows_amd64.c @@ -9,6 +9,7 @@ #include <stdio.h> #include <errno.h> #include "libcgo.h" +#include "libcgo_windows.h" static void threadentry(void*); diff --git a/src/runtime/cgo/libcgo_windows.h b/src/runtime/cgo/libcgo_windows.h new file mode 100644 index 0000000000..0013f06bae --- /dev/null +++ b/src/runtime/cgo/libcgo_windows.h @@ -0,0 +1,12 @@ +// Copyright 2020 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Ensure there's one symbol marked __declspec(dllexport). +// If there are no exported symbols, the unfortunate behavior of +// the binutils linker is to also strip the relocations table, +// resulting in non-PIE binary. The other option is the +// --export-all-symbols flag, but we don't need to export all symbols +// and this may overflow the export table (#40795). +// See https://sourceware.org/bugzilla/show_bug.cgi?id=19011 +__declspec(dllexport) int _cgo_dummy_export; |