Reviewed-by: Liming Gao <[email protected]> >-----Original Message----- >From: Zenith432 [mailto:[email protected]] >Sent: Tuesday, July 10, 2018 4:51 PM >To: [email protected] >Cc: Gao, Liming <[email protected]> >Subject: [PATCH v2] BaseTools/GenFw: Disable support for R_X86_64_32S > > >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
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