[PATCH] D35767: [COFF] Correctly set the thumb bit in DLL export addresses

Martin Storsjö via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Mon Jul 24 13:19:50 PDT 2017


mstorsjo updated this revision to Diff 107952.
mstorsjo added a comment.

Merged the test input data into the test itself, as suggested by Rui.


https://reviews.llvm.org/D35767

Files:
  COFF/DLL.cpp
  test/COFF/export-armnt.yaml


Index: test/COFF/export-armnt.yaml
===================================================================
--- /dev/null
+++ test/COFF/export-armnt.yaml
@@ -0,0 +1,72 @@
+# REQUIRES: arm
+
+# RUN: yaml2obj < %s > %t.obj
+#
+# RUN: lld-link /out:%t.dll /dll %t.obj /export:exportfn1 /export:exportfn2
+# RUN: llvm-objdump -p %t.dll | FileCheck %s
+
+# CHECK:      Export Table:
+# CHECK:      DLL name: export-armnt.yaml.tmp.dll
+# CHECK:      Ordinal      RVA  Name
+# CHECK-NEXT:       0        0
+# CHECK-NEXT:       1   0x1005  exportfn1
+# CHECK-NEXT:       2   0x1009  exportfn2
+# CHECK-NEXT:       3   0x1009  exportfn3
+
+--- !COFF
+header:
+  Machine:         IMAGE_FILE_MACHINE_ARMNT
+  Characteristics: []
+sections:
+  - Name:            .text
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    Alignment:       4
+    SectionData:     704700bf704700bf704700bf
+  - Name:            .drectve
+    Characteristics: [ IMAGE_SCN_LNK_INFO, IMAGE_SCN_LNK_REMOVE ]
+    Alignment:       1
+    SectionData:     2f6578706f72743a6578706f7274666e3300  # /export:exportfn3
+symbols:
+  - Name:            .text
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          12
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          0
+  - Name:            _DllMainCRTStartup
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            exportfn1
+    Value:           4
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            exportfn2
+    Value:           8
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            exportfn3
+    Value:           8
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            '?mangled@@YAHXZ'
+    Value:           8
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+...
Index: COFF/DLL.cpp
===================================================================
--- COFF/DLL.cpp
+++ COFF/DLL.cpp
@@ -319,12 +319,16 @@
   size_t getSize() const override { return Size * 4; }
 
   void writeTo(uint8_t *Buf) const override {
+    uint32_t Bit = 0;
+    // Pointer to thumb code must have the LSB set, so adjust it.
+    if (Config->Machine == ARMNT)
+      Bit = 1;
     for (Export &E : Config->Exports) {
       uint8_t *P = Buf + OutputSectionOff + E.Ordinal * 4;
       if (E.ForwardChunk) {
-        write32le(P, E.ForwardChunk->getRVA());
+        write32le(P, E.ForwardChunk->getRVA() | Bit);
       } else {
-        write32le(P, cast<Defined>(E.Sym)->getRVA());
+        write32le(P, cast<Defined>(E.Sym)->getRVA() | Bit);
       }
     }
   }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D35767.107952.patch
Type: text/x-patch
Size: 3351 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20170724/9d487458/attachment.bin>


More information about the llvm-commits mailing list