[PATCH] D65388: [llvm-readelf/llvm-readobj] - Test the case when e_shstrndx==SHN_XINDEX, but sec[0].sh_link is broken.

[George Rimar via Phabricator via llvm-commits]

grimar created this revision.
grimar added reviewers: jhenderson, MaskRay.
Herald added subscribers: rupprecht, arphaman.

When `e_shstrndx` is equal to `SHN_XINDEX`,
the index of the section string table section should
be taken from zero section `sh_link` field.
If `sh_link` is broken, e.g. contains an index that is
larger than number of sections, then error is reported.

This error message was untested before.


https://reviews.llvm.org/D65388

Files:
  test/tools/llvm-readobj/elf-invalid-sechdr-strtab-index.test
  test/tools/llvm-readobj/elf-invalid-shstrndx.test
  tools/llvm-readobj/ELFDumper.cpp


Index: tools/llvm-readobj/ELFDumper.cpp
===================================================================
--- tools/llvm-readobj/ELFDumper.cpp
+++ tools/llvm-readobj/ELFDumper.cpp
@@ -3015,7 +3015,6 @@
     Index = Sections[0].sh_link;
   if (!Index) // no section string table.
     return "";
-  // TODO: Test a case when the sh_link of the section with index 0 is broken.
   if (Index >= Sections.size())
     reportError(ElfObj.getFileName(),
                 createError("section header string table index " +
Index: test/tools/llvm-readobj/elf-invalid-shstrndx.test
===================================================================
--- test/tools/llvm-readobj/elf-invalid-shstrndx.test
+++ /dev/null
@@ -1,26 +0,0 @@
-# RUN: yaml2obj %s -o %t
-# RUN: not llvm-readelf --headers -S 2>&1 %t | FileCheck %s -DFILE=%t --check-prefix=GNU
-# RUN: not llvm-readobj --headers -S 2>&1 %t | FileCheck %s -DFILE=%t --check-prefix=LLVM
-
-# GNU:      ELF Header:
-# GNU:        Section header string table index: 255
-# GNU-NEXT:   There are 4 section headers, starting at offset 0x40:
-# GNU:      Section Headers:
-# GNU-NEXT:  [Nr] Name
-# GNU-EMPTY:
-# GNU-NEXT:  error: '[[FILE]]': section header string table index 255 does not exist
-
-# LLVM:      ElfHeader {
-# LLVM:        StringTableSectionIndex: 255
-# LLVM-NEXT: }
-# LLVM-NEXT: Sections [
-# LLVM-EMPTY:
-# LLVM-NEXT: error: '[[FILE]]': section header string table index 255 does not exist
-
---- !ELF
-FileHeader:
-  Class:     ELFCLASS64
-  Data:      ELFDATA2LSB
-  Type:      ET_REL
-  Machine:   EM_X86_64
-  SHStrNdx:  0xFF
Index: test/tools/llvm-readobj/elf-invalid-sechdr-strtab-index.test
===================================================================
--- /dev/null
+++ test/tools/llvm-readobj/elf-invalid-sechdr-strtab-index.test
@@ -0,0 +1,46 @@
+## Check the case when e_shstrndx contains an invalid section header table index.
+
+# RUN: yaml2obj --docnum=1 %s -o %t1
+# RUN: not llvm-readelf --headers -S 2>&1 %t1 | FileCheck %s -DFILE=%t1 --check-prefixes=GNU,GNU-SHSTRNDX
+# RUN: not llvm-readobj --headers -S 2>&1 %t1 | FileCheck %s -DFILE=%t1 --check-prefixes=LLVM,LLVM-SHSTRNDX
+
+# GNU:          ELF Header:
+# GNU-SHSTRNDX:  Section header string table index: 255
+# GNU-LINK:      Section header string table index: 65535 (255)
+# GNU-NEXT:      There are 4 section headers, starting at offset 0x40:
+# GNU:          Section Headers:
+# GNU-NEXT:      [Nr] Name
+# GNU-EMPTY:
+# GNU-NEXT:      error: '[[FILE]]': section header string table index 255 does not exist
+
+# LLVM:          ElfHeader {
+# LLVM-SHSTRNDX:  StringTableSectionIndex: 255
+# LLVM-LINK:      StringTableSectionIndex: 65535 (255)
+# LLVM-NEXT:     }
+# LLVM-NEXT:     Sections [
+# LLVM-EMPTY:
+# LLVM-NEXT:     error: '[[FILE]]': section header string table index 255 does not exist
+
+--- !ELF
+FileHeader:
+  Class:     ELFCLASS64
+  Data:      ELFDATA2LSB
+  Type:      ET_REL
+  Machine:   EM_X86_64
+  SHStrNdx:  0xFF
+
+# RUN: yaml2obj --docnum=2 %s -o %t2
+# RUN: not llvm-readelf --headers -S 2>&1 %t2 | FileCheck %s -DFILE=%t2 --check-prefixes=GNU,GNU-LINK
+# RUN: not llvm-readobj --headers -S 2>&1 %t2 | FileCheck %s -DFILE=%t2 --check-prefixes=LLVM,LLVM-LINK
+
+--- !ELF
+FileHeader:
+  Class:    ELFCLASS64
+  Data:     ELFDATA2LSB
+  Type:     ET_REL
+  Machine:  EM_X86_64
+## SHN_XINDEX == 0xffff.
+  SHStrNdx: 0xffff
+Sections:
+  - Type: SHT_NULL
+    Link: 0xff


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