REF:https://bugzilla.tianocore.org/show_bug.cgi?id=999
Cc: Liming Gao <[email protected]> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Zenith432 <[email protected]> --- BaseTools/Source/C/GenFw/Elf64Convert.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/BaseTools/Source/C/GenFw/Elf64Convert.c b/BaseTools/Source/C/GenFw/Elf64Convert.c index 4636cfee..e42cc3f7 100644 --- a/BaseTools/Source/C/GenFw/Elf64Convert.c +++ b/BaseTools/Source/C/GenFw/Elf64Convert.c @@ -993,7 +993,28 @@ WriteRelocations64 ( + (Rel->r_offset - SecShdr->sh_addr)), EFI_IMAGE_REL_BASED_DIR64); break; - case R_X86_64_32S: + // + // 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: 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 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
