[llvm] r272911 - [PATCH] Fix RuntimeDyldCOFFI386 to handle relocations with a non-zero addend

[Reid Kleckner via llvm-commits]

Author: rnk
Date: Thu Jun 16 11:21:41 2016
New Revision: 272911

URL: http://llvm.org/viewvc/llvm-project?rev=272911&view=rev
Log:
[PATCH] Fix RuntimeDyldCOFFI386 to handle relocations with a non-zero addend

This fixes IMAGE_REL_I386_DIR32, IMAGE_REL_I386_DIR32NB,
IMAGE_REL_I386_SECREL, and IMAGE_REL_I386_REL32 relocations.

Based on patch by Jon Turney <jon.turney at dronecode.org.uk>

Modified:
    llvm/trunk/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFI386.h
    llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/COFF_i386.s

Modified: llvm/trunk/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFI386.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFI386.h?rev=272911&r1=272910&r2=272911&view=diff
==============================================================================
--- llvm/trunk/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFI386.h (original)
+++ llvm/trunk/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFI386.h Thu Jun 16 11:21:41 2016
@@ -58,13 +58,31 @@ public:
     uint64_t RelType = RelI->getType();
     uint64_t Offset = RelI->getOffset();
 
+    // Determine the Addend used to adjust the relocation value.
+    uint64_t Addend = 0;
+    SectionEntry &AddendSection = Sections[SectionID];
+    uintptr_t ObjTarget = AddendSection.getObjAddress() + Offset;
+    uint8_t *Displacement = (uint8_t *)ObjTarget;
+
+    switch (RelType) {
+    case COFF::IMAGE_REL_I386_DIR32:
+    case COFF::IMAGE_REL_I386_DIR32NB:
+    case COFF::IMAGE_REL_I386_SECREL:
+    case COFF::IMAGE_REL_I386_REL32: {
+      Addend = readBytesUnaligned(Displacement, 4);
+      break;
+    }
+    default:
+      break;
+    }
+
 #if !defined(NDEBUG)
     SmallString<32> RelTypeName;
     RelI->getTypeName(RelTypeName);
 #endif
     DEBUG(dbgs() << "\t\tIn Section " << SectionID << " Offset " << Offset
                  << " RelType: " << RelTypeName << " TargetName: " << TargetName
-                 << "\n");
+                 << " Addend " << Addend << "\n");
 
     unsigned TargetSectionID = -1;
     if (Section == Obj.section_end()) {
@@ -85,7 +103,7 @@ public:
       case COFF::IMAGE_REL_I386_DIR32NB:
       case COFF::IMAGE_REL_I386_REL32: {
         RelocationEntry RE =
-            RelocationEntry(SectionID, Offset, RelType, 0, TargetSectionID,
+            RelocationEntry(SectionID, Offset, RelType, Addend, TargetSectionID,
                             getSymbolOffset(*Symbol), 0, 0, false, 0);
         addRelocationForSection(RE, TargetSectionID);
         break;
@@ -98,7 +116,7 @@ public:
       }
       case COFF::IMAGE_REL_I386_SECREL: {
         RelocationEntry RE = RelocationEntry(SectionID, Offset, RelType,
-                                             getSymbolOffset(*Symbol));
+                                             getSymbolOffset(*Symbol) + Addend);
         addRelocationForSection(RE, TargetSectionID);
         break;
       }

Modified: llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/COFF_i386.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/COFF_i386.s?rev=272911&r1=272910&r2=272911&view=diff
==============================================================================
--- llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/COFF_i386.s (original)
+++ llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/COFF_i386.s Thu Jun 16 11:21:41 2016
@@ -64,3 +64,16 @@ rel7:
 # rtdyld-check: *{4}rel7 = relocations - section_addr(COFF_i386.s.tmp.obj, .data)
 	.secrel32 relocations			// IMAGE_REL_I386_SECREL
 
+# Test that addends work.
+rel8:
+# rtdyld-check: *{4}rel8 = string
+	.long string				// IMAGE_REL_I386_DIR32
+rel9:
+# rtdyld-check: *{4}rel9 = string+1
+	.long string+1				// IMAGE_REL_I386_DIR32
+rel10:
+# rtdyld-check: *{4}rel10 = string - section_addr(COFF_i386.s.tmp.obj, .text) + 1
+	.long string at imgrel+1			// IMAGE_REL_I386_DIR32NB
+rel11:
+# rtdyld-check: *{4}rel11 = string - section_addr(COFF_i386.s.tmp.obj, .data) + 1
+	.long string at SECREL32+1			// IMAGE_REL_I386_SECREL