[PATCH] D70842: [llvm-readelf/llvm-readobj] - Check the version of SHT_GNU_verneed section entries.

[George Rimar via Phabricator via llvm-commits]

grimar created this revision.
grimar added reviewers: jhenderson, MaskRay.
Herald added subscribers: seiya, dmgreen, rupprecht.
Herald added a project: LLVM.

It is a follow-up for D70826 <https://reviews.llvm.org/D70826> and it is similar to D70810 <https://reviews.llvm.org/D70810>.

SHT_GNU_verneed contains the following fields:
`vn_version`: Version of structure. This value is currently set to 1, and will be reset
if the versioning implementation is incompatibly altered.
(https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/symversion.html)

We should check it for correctness.


https://reviews.llvm.org/D70842

Files:
  llvm/test/tools/llvm-readobj/elf-verneed-invalid.test
  llvm/tools/llvm-readobj/ELFDumper.cpp


Index: llvm/tools/llvm-readobj/ELFDumper.cpp
===================================================================
--- llvm/tools/llvm-readobj/ELFDumper.cpp
+++ llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -505,6 +505,12 @@
           ": found a misaligned version dependency entry at offset 0x" +
           Twine::utohexstr(VerneedBuf - Start));
 
+    unsigned Version = *reinterpret_cast<const Elf_Half *>(VerneedBuf);
+    if (Version != 1)
+      return createError("unable to dump SHT_GNU_verneed section with index " +
+                         Twine(SecNdx) + ": version " + Twine(Version) +
+                         " is not yet supported");
+
     const Elf_Verneed *Verneed =
         reinterpret_cast<const Elf_Verneed *>(VerneedBuf);
 
Index: llvm/test/tools/llvm-readobj/elf-verneed-invalid.test
===================================================================
--- llvm/test/tools/llvm-readobj/elf-verneed-invalid.test
+++ llvm/test/tools/llvm-readobj/elf-verneed-invalid.test
@@ -503,3 +503,34 @@
     Content: "0100010001000000110000000000000000000000"
 DynamicSymbols:
   - Name: foo
+
+## Check how we handle the case when a dependency definition entry has an unsupported version.
+
+# RUN: yaml2obj %s --docnum=12 -o %t12
+# RUN: llvm-readobj -V %t12 2>&1 | FileCheck %s --check-prefix=UNSUPPORTED-VERSION -DFILE=%t12
+# RUN: llvm-readelf -V %t12 2>&1 | FileCheck %s --check-prefix=UNSUPPORTED-VERSION -DFILE=%t12
+
+# UNSUPPORTED-VERSION: warning: '[[FILE]]': unable to dump SHT_GNU_verneed section with index 1: version 65278 is not yet supported
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name:  .gnu.version_r
+    Type:  SHT_GNU_verneed
+    Flags: [ SHF_ALLOC ]
+    Info:  1
+    Link:  .dynstr
+    Dependencies:
+      - Version: 0xfefe
+        File:    foo
+        Entries:
+          - Name:  'foo'
+            Hash:  0
+            Flags: 0
+            Other: 0
+DynamicSymbols:
+  - Name: foo


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