[PATCH] BaseTools/GenFw: Disable support for R_X86_64_32S

[Zenith432 <zenith432@users.sourceforge.net>]

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=999

Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Zenith432 <zenith432@users.sourceforge.net>
---
 BaseTools/Source/C/GenFw/Elf64Convert.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/BaseTools/Source/C/GenFw/Elf64Convert.c b/BaseTools/Source/C/GenFw/Elf64Convert.c
index 4636cfee..a4feaf7c 100644
--- a/BaseTools/Source/C/GenFw/Elf64Convert.c
+++ b/BaseTools/Source/C/GenFw/Elf64Convert.c
@@ -993,7 +993,30 @@ WriteRelocations64 (
                 + (Rel->r_offset - SecShdr->sh_addr)),
                 EFI_IMAGE_REL_BASED_DIR64);
               break;
+#if 0
+            //
+            // R_X86_64_32 and R_X86_64_32S are ELF64 relocations emitted when using
+            //   the SYSV X64 ABI small non-position-independent code model.
+            //   R_X86_64_32 is used for unsigned 32-bit immediates with a 32-bit operand
+            //   size.  The value is either not extended, or zero-extended to 64 bits.
+            //   R_X86_64_32S is used for either signed 32-bit non-rip-relative displacements
+            //   or signed 32-bit immediates with a 64-bit operand size.  The value is
+            //   sign-extended to 64 bits.
+            //   EFI_IMAGE_REL_BASED_HIGHLOW is a PE relocation that uses 32-bit arithmetic
+            //   for rebasing an image.
+            //   EFI PE binaries declare themselves EFI_IMAGE_FILE_LARGE_ADDRESS_AWARE and
+            //   may load above 2GB.  If an EFI PE binary with a converted R_X86_64_32S
+            //   relocation is loaded above 2GB, the value will get sign-extended to the
+            //   negative part of the 64-bit address space.  The negative part of the 64-bit
+            //   address space is unmapped, so accessing such an address page-faults.
+            //   In order to support R_X86_64_32S, it is necessary to unset
+            //   EFI_IMAGE_FILE_LARGE_ADDRESS_AWARE, and the EFI PE loader must implement
+            //   this flag and abstain from loading such a PE binary above 2GB.
+            //   Since this feature is not supported, support for R_X86_64_32S (and hence
+            //   the small non-position-independent code model) is disabled.
+            //
             case R_X86_64_32S:
+#endif
             case R_X86_64_32:
               VerboseMsg ("EFI_IMAGE_REL_BASED_HIGHLOW Offset: 0x%08X",
                 mCoffSectionsOffset[RelShdr->sh_info] + (Rel->r_offset - SecShdr->sh_addr));
-- 
2.17.1