[llvm] c5d8bd5 - [llvm-objcopy] Fix section group flag read/write when operating on a cross-endian object file

[Fangrui Song via llvm-commits]

Author: Fangrui Song
Date: 2021-07-26T15:09:15-07:00
New Revision: c5d8bd5a35cbd325c6ccd42afa91bad06d261f07

URL: https://github.com/llvm/llvm-project/commit/c5d8bd5a35cbd325c6ccd42afa91bad06d261f07
DIFF: https://github.com/llvm/llvm-project/commit/c5d8bd5a35cbd325c6ccd42afa91bad06d261f07.diff

LOG: [llvm-objcopy] Fix section group flag read/write when operating on a cross-endian object file

Added: 
    

Modified: 
    llvm/tools/llvm-objcopy/ELF/Object.cpp

Removed: 
    


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diff  --git a/llvm/tools/llvm-objcopy/ELF/Object.cpp b/llvm/tools/llvm-objcopy/ELF/Object.cpp
index 91a73f2111ae..ba91d08e5540 100644
--- a/llvm/tools/llvm-objcopy/ELF/Object.cpp
+++ b/llvm/tools/llvm-objcopy/ELF/Object.cpp
@@ -1187,7 +1187,7 @@ template <class ELFT>
 Error ELFSectionWriter<ELFT>::visit(const GroupSection &Sec) {
   ELF::Elf32_Word *Buf =
       reinterpret_cast<ELF::Elf32_Word *>(Out.getBufferStart() + Sec.Offset);
-  *Buf++ = Sec.FlagWord;
+  support::endian::write32<ELFT::TargetEndianness>(Buf++, Sec.FlagWord);
   for (SectionBase *S : Sec.GroupMembers)
     support::endian::write32<ELFT::TargetEndianness>(Buf++, S->Index);
   return Error::success();
@@ -1517,7 +1517,8 @@ Error ELFBuilder<ELFT>::initGroupSection(GroupSection *GroupSec) {
       reinterpret_cast<const ELF::Elf32_Word *>(GroupSec->Contents.data());
   const ELF::Elf32_Word *End =
       Word + GroupSec->Contents.size() / sizeof(ELF::Elf32_Word);
-  GroupSec->setFlagWord(*Word++);
+  GroupSec->setFlagWord(
+      support::endian::read32<ELFT::TargetEndianness>(Word++));
   for (; Word != End; ++Word) {
     uint32_t Index = support::endian::read32<ELFT::TargetEndianness>(Word);
     Expected<SectionBase *> Sec = SecTable.getSection(