GNU Binutils produce a PE debug directory with one
EFI_IMAGE_DEBUG_DIRECTORY_ENTRY:
- the Type field of the entry is EFI_IMAGE_DEBUG_TYPE_CODEVIEW,
- the FileOffset field of the entry points right past the entry itself,
- the data structure placed at FileOffset is a CV_INFO_PDB20 structure,
with an "NB10" signature.
This is all correct, except GNU Binutils include the pointed-to
CV_INFO_PDB20 structure in the size of the debug directory (that is,
Optional64Hdr->DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_DEBUG].Size).
That's a bug.
The malformed debug directory size causes the loop in GenFw's
ZeroDebugData() function to process the CV_INFO_PDB20 structure as a set
of EFI_IMAGE_DEBUG_DIRECTORY_ENTRY elements, which crashes GenFw.
This problem was exposed by commit e4129b0e5897 ("BaseTools: Update GenFw
to clear unused debug entry generated by VS tool chain", 2017-06-19).
Work around the Binutils issue by noticing when an
EFI_IMAGE_DEBUG_DIRECTORY_ENTRY.FileOffset points back into the debug
directory. (This can never happen with a well-formed PE file.) In this
case, truncate DebugDirectoryEntrySize such that the debug directory will
end right before the debug structure pointed-to by
EFI_IMAGE_DEBUG_DIRECTORY_ENTRY.FileOffset.
Tested with OVMF:
- gcc-4.8.5-14.el7.x86_64
- binutils-2.25.1-27.base.el7.x86_64
and with ArmVirtPkg:
- gcc-aarch64-linux-gnu-6.1.1-2.el7.x86_64
- binutils-aarch64-linux-gnu-2.27-3.el7.x86_64
Cc: Ard Biesheuvel <ard.biesheu...@linaro.org>
Cc: Gerd Hoffmann <kra...@redhat.com>
Cc: Leif Lindholm <leif.lindh...@linaro.org>
Cc: Liming Gao <liming....@intel.com>
Cc: Yonghong Zhu <yonghong....@intel.com>
Reported-by: Gerd Hoffmann <kra...@redhat.com>
Reported-by: Leif Lindholm <leif.lindh...@linaro.org>
Ref: a1de67a8-57c2-908e-dd4d-9726d60fb388@redhat.com">http://mid.mail-archive.com/a1de67a8-57c2-908e-dd4d-9726d60fb388@redhat.com
Ref: 20170705134136.GB26676@bivouac.eciton.net">http://mid.mail-archive.com/20170705134136.GB26676@bivouac.eciton.net
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <ler...@redhat.com>
---
Notes:
Repo: https://github.com/lersek/edk2.git
Branch: binutils_debugdirsize_workaround
BaseTools/Source/C/GenFw/GenFw.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/BaseTools/Source/C/GenFw/GenFw.c b/BaseTools/Source/C/GenFw/GenFw.c
index 6569460f34f7..a79f485ee681 100644
--- a/BaseTools/Source/C/GenFw/GenFw.c
+++ b/BaseTools/Source/C/GenFw/GenFw.c
@@ -2771,6 +2771,7 @@ Returns:
UINT32 Index;
UINT32 DebugDirectoryEntryRva;
UINT32 DebugDirectoryEntrySize;
+ UINT32 TruncatedDebugDirectorySize;
UINT32 DebugDirectoryEntryFileOffset;
UINT32 ExportDirectoryEntryRva;
UINT32 ExportDirectoryEntryFileOffset;
@@ -2893,6 +2894,25 @@ Returns:
DebugEntry = (EFI_IMAGE_DEBUG_DIRECTORY_ENTRY *) (FileBuffer +
DebugDirectoryEntryFileOffset);
Index = 0;
for (Index=0; Index < DebugDirectoryEntrySize / sizeof
(EFI_IMAGE_DEBUG_DIRECTORY_ENTRY); Index ++, DebugEntry ++) {
+ //
+ // Work around GNU Binutils bug: if the debug information pointed-to by
+ // DebugEntry was incorrectly included in DebugDirectoryEntrySize, then
+ // the debug directory doesn't actually extend past the pointed-to debug
+ // information. Truncate DebugDirectoryEntrySize accordingly.
+ //
+ if (DebugEntry->FileOffset >= DebugDirectoryEntryFileOffset &&
+ DebugEntry->FileOffset < (DebugDirectoryEntryFileOffset +
+ DebugDirectoryEntrySize)) {
+ TruncatedDebugDirectorySize = (DebugEntry->FileOffset -
+ DebugDirectoryEntryFileOffset);
+ VerboseMsg (
+ "truncating debug directory size from %u to %u",
+ DebugDirectoryEntrySize,
+ TruncatedDebugDirectorySize
+ );
+ DebugDirectoryEntrySize = TruncatedDebugDirectorySize;
+ }
+
DebugEntry->TimeDateStamp = 0;
if (ZeroDebugFlag || DebugEntry->Type != EFI_IMAGE_DEBUG_TYPE_CODEVIEW) {
memset (FileBuffer + DebugEntry->FileOffset, 0,
DebugEntry->SizeOfData);
--
2.13.1.3.g8be5a757fa67
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