[PATCH] D89373: Fixed dangling reference in RuntimeDyldELF

[Moritz Sichert via Phabricator via llvm-commits]

MoritzS created this revision.
Herald added subscribers: llvm-commits, hiraditya.
Herald added a project: LLVM.
MoritzS requested review of this revision.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D89373

Files:
  llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp


Index: llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
===================================================================
--- llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
+++ llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
@@ -1676,30 +1676,33 @@
       if (Value.SymbolName) {
         // This is a call to an external function.
         // Look for an existing stub.
-        SectionEntry &Section = Sections[SectionID];
+        SectionEntry *Section = &Sections[SectionID];
         StubMap::const_iterator i = Stubs.find(Value);
         uintptr_t StubAddress;
         if (i != Stubs.end()) {
-          StubAddress = uintptr_t(Section.getAddress()) + i->second;
+          StubAddress = uintptr_t(Section->getAddress()) + i->second;
           LLVM_DEBUG(dbgs() << " Stub function found\n");
         } else {
           // Create a new stub function (equivalent to a PLT entry).
           LLVM_DEBUG(dbgs() << " Create a new stub function\n");
 
-          uintptr_t BaseAddress = uintptr_t(Section.getAddress());
+          uintptr_t BaseAddress = uintptr_t(Section->getAddress());
           uintptr_t StubAlignment = getStubAlignment();
           StubAddress =
-              (BaseAddress + Section.getStubOffset() + StubAlignment - 1) &
+              (BaseAddress + Section->getStubOffset() + StubAlignment - 1) &
               -StubAlignment;
           unsigned StubOffset = StubAddress - BaseAddress;
           Stubs[Value] = StubOffset;
           createStubFunction((uint8_t *)StubAddress);
 
           // Bump our stub offset counter
-          Section.advanceStubOffset(getMaxStubSize());
+          Section->advanceStubOffset(getMaxStubSize());
 
           // Allocate a GOT Entry
           uint64_t GOTOffset = allocateGOTEntries(1);
+          // This potentially creates a new Section which potentially
+          // invalidates the Section pointer, so reload it.
+          Section = &Sections[SectionID];
 
           // The load of the GOT address has an addend of -4
           resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4,
@@ -1712,8 +1715,8 @@
         }
 
         // Make the target call a call into the stub table.
-        resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
-                          Addend);
+        resolveRelocation(*Section, Offset, StubAddress, Flags,
+                          ELF::R_X86_64_PC32, Addend);
       } else {
         RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
                   Value.Offset);


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