From 5279f96577af1457a973c071ec5ee3554c9f6cbe Mon Sep 17 00:00:00 2001
From: Igor Kudrin <ikudrin@accesssoftek.com>
Date: Mon, 16 Dec 2019 21:16:14 +0700
Subject: [PATCH] [MachO] Fix detecting malformed DWARF.

This fixes an invalid constant used to detect the reserved range when
reading the compilation unit header. See also: D64622 and D65039.

Differential Revision: https://reviews.llvm.org/D71546
---
 lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
index 0163c90189fd..6f294b1ecd0f 100644
--- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
+++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
@@ -879,11 +879,11 @@ readCompUnit(const NormalizedFile &normalizedFile,
   llvm::dwarf::DwarfFormat Format = llvm::dwarf::DwarfFormat::DWARF32;
   auto infoData = dataExtractorFromSection(normalizedFile, info);
   uint32_t length = infoData.getU32(&offset);
-  if (length == 0xffffffff) {
+  if (length == llvm::dwarf::DW_LENGTH_DWARF64) {
     Format = llvm::dwarf::DwarfFormat::DWARF64;
     infoData.getU64(&offset);
   }
-  else if (length > 0xffffff00)
+  else if (length >= llvm::dwarf::DW_LENGTH_lo_reserved)
     return llvm::make_error<GenericError>("Malformed DWARF in " + path);
 
   uint16_t version = infoData.getU16(&offset);