replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Revert "Write a hash of the executable into the PE timestamp fields." 

This is breaking a couple of tests, so I'm reverting temporarily
until I can get everything resolved properly.

llvm-svn: 326943
This commit is contained in:
Zachary Turner 2018-03-07 21:22:10 +00:00
parent 0a6a701f36
commit 0b4af0434b
1 changed files with 15 additions and 51 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

66
lld/COFF/Writer.cpp
View File

@ -28,7 +28,6 @@
#include "llvm/Support/Parallel.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/RandomNumberGenerator.h"
#include "llvm/Support/xxhash.h"
#include <algorithm>
#include <cstdio>
#include <map>
@ -72,18 +71,11 @@ public:
uint64_t Offs = OS->getFileOff() + (Record->getRVA() - OS->getRVA());
D->PointerToRawData = Offs;
TimeDateStamps.push_back(&D->TimeDateStamp);
++D;
}
}
void setTimeDateStamp(uint32_t TimeDateStamp) {
for (support::ulittle32_t *TDS : TimeDateStamps)
*TDS = TimeDateStamp;
}
private:
mutable std::vector<support::ulittle32_t *> TimeDateStamps;
const std::vector<Chunk *> &Records;
};
@ -165,7 +157,7 @@ private:
RVATableChunk *GuardFidsTable = nullptr;
RVATableChunk *SEHTable = nullptr;
DebugDirectoryChunk *DebugDirectory = nullptr;
Chunk *DebugDirectory = nullptr;
std::vector<Chunk *> DebugRecords;
CVDebugRecordChunk *BuildId = nullptr;
Optional<codeview::DebugInfo> PreviousBuildId;
@ -1034,50 +1026,22 @@ void Writer::writeSections() {
}
void Writer::writeBuildId() {
// There are two important parts to the build ID.
// 1) If building with debug info, the COFF debug directory contains a
// timestamp as well as a Guid and Age of the PDB.
// 2) In all cases, the PE COFF file header also contains a timestamp.
// For reproducibility, instead of a timestamp we want to use a hash of the
// binary, however when building with debug info the hash needs to take into
// account the debug info, since it's possible to add blank lines to a file
// which causes the debug info to change but not the generated code.
//
// To handle this, we first set the Guid and Age in the debug directory (but
// only if we're doing a debug build). Then, we hash the binary (thus causing
// the hash to change if only the debug info changes, since the Age will be
// different). Finally, we write that hash into the debug directory (if
// present) as well as the COFF file header (always).
if (Config->Debug) {
assert(BuildId && "BuildId is not set!");
if (PreviousBuildId.hasValue()) {
*BuildId->BuildId = *PreviousBuildId;
BuildId->BuildId->PDB70.Age = BuildId->BuildId->PDB70.Age + 1;
} else {
BuildId->BuildId->Signature.CVSignature = OMF::Signature::PDB70;
BuildId->BuildId->PDB70.Age = 1;
llvm::getRandomBytes(BuildId->BuildId->PDB70.Signature, 16);
}
// If we're not writing a build id (e.g. because /debug is not specified),
// then just return;
if (!Config->Debug)
return;
assert(BuildId && "BuildId is not set!");
if (PreviousBuildId.hasValue()) {
*BuildId->BuildId = *PreviousBuildId;
BuildId->BuildId->PDB70.Age = BuildId->BuildId->PDB70.Age + 1;
return;
}
// At this point the only fields in the COFF file which remain unset are the
// "timestamp" in the COFF file header, and the ones in the coff debug
// directory. Now we can hash the file and write that hash to the various
// timestamp fields in the file.
StringRef OutputFileData(
reinterpret_cast<const char *>(Buffer->getBufferStart()),
Buffer->getBufferSize());
uint32_t Hash = static_cast<uint32_t>(xxHash64(OutputFileData));
if (DebugDirectory)
DebugDirectory->setTimeDateStamp(Hash);
uint8_t *Buf = Buffer->getBufferStart();
Buf += DOSStubSize + sizeof(PEMagic);
object::coff_file_header *CoffHeader =
reinterpret_cast<coff_file_header *>(Buf);
CoffHeader->TimeDateStamp = Hash;
BuildId->BuildId->Signature.CVSignature = OMF::Signature::PDB70;
BuildId->BuildId->PDB70.Age = 1;
llvm::getRandomBytes(BuildId->BuildId->PDB70.Signature, 16);
}
// Sort .pdata section contents according to PE/COFF spec 5.5.