[RuntimeDyld][MachO] Fix handling of empty eh-frame sections.

This patch switches from an unguarded to a guarded loop for eh-frame record fixups. In the unguarded version we would always make at least one call to processFDE, which would then crash trying to fix up a frame that didn't exist. Fixes <rdar://problem/24301582> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259103 91177308-0d34-0410-b5e6-96231b3b80d8
zoren · Jan 28, 2016 · 88ffce3 · 88ffce3
1 parent 681c4b8
commit 88ffce3
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
@@ -302,9 +302,9 @@ void RuntimeDyldMachOCRTPBase<Impl>::registerEHFrames() {
 
     uint8_t *P = EHFrame->getAddress();
     uint8_t *End = P + EHFrame->getSize();
-    do {
+    while (P != End) {
       P = processFDE(P, DeltaForText, DeltaForEH);
-    } while (P != End);
+    }
 
     MemMgr.registerEHFrames(EHFrame->getAddress(), EHFrame->getLoadAddress(),
                             EHFrame->getSize());

diff --git a/test/ExecutionEngine/RuntimeDyld/X86/MachO_empty_ehframe.s b/test/ExecutionEngine/RuntimeDyld/X86/MachO_empty_ehframe.s
@@ -0,0 +1,7 @@
+# RUN: llvm-mc -triple=x86_64-apple-macosx10.9 -filetype=obj -o %T/empty_eh_frame.o %s
+# RUN: llvm-rtdyld -verify -triple=x86_64-apple-macosx10.9 %T/empty_eh_frame.o
+
+        .section        __TEXT,__eh_frame
+	.macosx_version_min 10, 10
+
+.subsections_via_symbols