[llvm-readelf] - Allow dumping of the .dynamic section even if there is no PT_DYNAMIC header.

It is now possible after D61937 was landed and was discussed
in it's review comments. It is not consistent with GNU, which
does not output .dynamic section content in this case for
no visible reason.

Differential revision: https://reviews.llvm.org/D62179

llvm-svn: 361943

6 files changed, 112 insertions, 94 deletions

diff --git a/llvm/test/Object/corrupt.test b/llvm/test/Object/corrupt.test
index c98757885aa..49f973d43b1 100644
--- a/llvm/test/Object/corrupt.test
+++ b/llvm/test/Object/corrupt.test
@@ -38,11 +38,11 @@ RUN:   FileCheck --check-prefix=PHENTSIZE %s
 
 PHENTSIZE: invalid e_phentsize
 
-RUN: not llvm-readobj --dynamic-table \
+RUN: llvm-readobj --dynamic-table \
 RUN:   %p/Inputs/corrupt-invalid-virtual-addr.elf.x86-64 2>&1 | \
 RUN:   FileCheck --check-prefix=VIRTADDR %s
 
-VIRTADDR: Virtual address is not in any segment
+VIRTADDR: warning: Unable to parse DT_STRTAB: Virtual address is not in any segment
 
 
 RUN: not llvm-readobj --dyn-relocations \
diff --git a/llvm/test/Object/invalid.test b/llvm/test/Object/invalid.test
index 6f94f9d218d..921a5d6a7bc 100644
--- a/llvm/test/Object/invalid.test
+++ b/llvm/test/Object/invalid.test
@@ -40,9 +40,6 @@ SECTION-NEXT:    EntrySize: 32
 RUN: not llvm-readobj --symbols %p/Inputs/invalid-sh_entsize.elf 2>&1 | FileCheck --check-prefix=INVALID-SYM-SIZE %s
 INVALID-SYM-SIZE: invalid sh_entsize
 
-RUN: not llvm-readobj --dyn-symbols %p/Inputs/invalid-sh_entsize.elf 2>&1 | FileCheck --check-prefix=INVALID-DYNSYM-SIZE %s
-INVALID-DYNSYM-SIZE: Invalid entity size
-
 RUN: not llvm-readobj --symbols %p/Inputs/invalid-section-index.elf 2>&1 | FileCheck --check-prefix=INVALID-SECTION-INDEX %s
 INVALID-SECTION-INDEX: invalid section index
 
diff --git a/llvm/test/tools/llvm-readobj/elf-dynamic-malformed.test b/llvm/test/tools/llvm-readobj/elf-dynamic-malformed.test
index aaee340e1cc..abc0f89310c 100644
--- a/llvm/test/tools/llvm-readobj/elf-dynamic-malformed.test
+++ b/llvm/test/tools/llvm-readobj/elf-dynamic-malformed.test
@@ -114,7 +114,8 @@ ProgramHeaders:
 # RUN: not llvm-readobj --dynamic-table %t.bad-strtab 2>&1 | FileCheck %s --check-prefix BAD-STRTAB
 # RUN: not llvm-readelf --dynamic-table %t.bad-strtab 2>&1 | FileCheck %s --check-prefix BAD-STRTAB
 
-# BAD-STRTAB: LLVM ERROR: Virtual address is not in any segment
+# BAD-STRTAB: warning: Unable to parse DT_STRTAB: Virtual address is not in any segment
+# BAD-STRTAB: error: Invalid dynamic string table reference
 
 --- !ELF
 FileHeader:
@@ -147,10 +148,19 @@ ProgramHeaders:
 
 # Test handling of other d_ptr tags pointing outside the file's address space.
 # RUN: yaml2obj %s --docnum=5 -o %t.bad-rela
-# RUN: not llvm-readobj --dynamic-table %t.bad-rela 2>&1 | FileCheck %s --check-prefix BAD-RELA
-# RUN: not llvm-readelf --dynamic-table %t.bad-rela 2>&1 | FileCheck %s --check-prefix BAD-RELA
+# RUN: llvm-readobj --dynamic-table %t.bad-rela 2>&1 | FileCheck %s --check-prefixes=CHECK,BAD-RELA
+# RUN: llvm-readelf --dynamic-table %t.bad-rela 2>&1 | FileCheck %s --check-prefixes=CHECK,BAD-RELA-GNU
 
-# BAD-RELA: LLVM ERROR: Virtual address is not in any segment
+# CHECK: warning: Unable to parse DT_RELA: Virtual address is not in any segment
+# BAD-RELA:      DynamicSection [ (2 entries)
+# BAD-RELA-NEXT:   Tag                Type Name/Value
+# BAD-RELA-NEXT:   0x0000000000000007 RELA 0x1000000
+# BAD-RELA-NEXT:   0x0000000000000000 NULL 0x0
+# BAD-RELA-NEXT: ]
+# BAD-RELA-GNU:      Dynamic section at offset 0x1f0 contains 2 entries:
+# BAD-RELA-GNU-NEXT: Tag                Type   Name/Value
+# BAD-RELA-GNU-NEXT: 0x0000000000000007 (RELA) 0x1000000
+# BAD-RELA-GNU-NEXT: 0x0000000000000000 (NULL) 0x0
 
 --- !ELF
 FileHeader:
diff --git a/llvm/test/tools/llvm-readobj/elf-dynamic-no-pt-dynamic.test b/llvm/test/tools/llvm-readobj/elf-dynamic-no-pt-dynamic.test
index 3ef293714a8..89e660337b5 100644
--- a/llvm/test/tools/llvm-readobj/elf-dynamic-no-pt-dynamic.test
+++ b/llvm/test/tools/llvm-readobj/elf-dynamic-no-pt-dynamic.test
@@ -1,16 +1,22 @@
-# Show that no dumping occurs if there is no PT_DYNAMIC header.
+## Show that dumping occurs even if there is no PT_DYNAMIC header.
+## This is inconsistent with the GNU behavior, but seems to be more reasonable.
 # RUN: yaml2obj %s -o %t.no-phdr
 # RUN: llvm-readobj --dynamic-table %t.no-phdr | FileCheck %s --check-prefix=LLVM
-# RUN: llvm-readelf --dynamic-table %t.no-phdr | FileCheck %s --check-prefix=GNU --allow-empty
+# RUN: llvm-readelf --dynamic-table %t.no-phdr | FileCheck %s --check-prefix=GNU
 
 # LLVM:      File: {{.*}}.no-phdr
 # LLVM-NEXT: Format: ELF64-x86-64
 # LLVM-NEXT: Arch: x86_64
 # LLVM-NEXT: AddressSize: 64bit
 # LLVM-NEXT: LoadName:{{ *}}
-# LLVM-NOT:  {{.}}
+# LLVM-NEXT: DynamicSection [ (1 entries)
+# LLVM-NEXT:   Tag                Type Name/Value
+# LLVM-NEXT:   0x0000000000000000 NULL 0x0
+# LLVM-NEXT: ]
 
-# GNU-NOT: {{.}}
+# GNU:      Dynamic section at offset 0x1b8 contains 1 entries:
+# GNU-NEXT: Tag                Type   Name/Value
+# GNU-NEXT: 0x0000000000000000 (NULL) 0x0
 
 --- !ELF
 FileHeader:
diff --git a/llvm/test/tools/yaml2obj/dynamic-section-raw-content.yaml b/llvm/test/tools/yaml2obj/dynamic-section-raw-content.yaml
index 37af06755a9..81008bcd852 100644
--- a/llvm/test/tools/yaml2obj/dynamic-section-raw-content.yaml
+++ b/llvm/test/tools/yaml2obj/dynamic-section-raw-content.yaml
@@ -10,10 +10,10 @@
 # RAW-NEXT: ]
 # RAW-NEXT: Address:
 # RAW-NEXT: Offset:
-# RAW-NEXT: Size: 5
+# RAW-NEXT: Size: 16
 
 # RAW:      Hex dump of section '.dynamic':
-# RAW-NEXT: 0x00000000 01234567 89 {{.*}}
+# RAW-NEXT: 0x00000000 01234567 89012345 67890000 00000000 {{.*}}
 
 # RUN: not yaml2obj --docnum=2 %s -o %t2 2>&1 | FileCheck %s --check-prefix=ERR
 # ERR: Cannot specify both raw content and explicit entries for dynamic section '.dynamic'.
@@ -27,7 +27,7 @@ FileHeader:
 Sections:
   - Name: .dynamic
     Type: SHT_DYNAMIC
-    Content: "0123456789"
+    Content: "01234567890123456789000000000000"
 
 --- !ELF
 FileHeader:
diff --git a/llvm/tools/llvm-readobj/ELFDumper.cpp b/llvm/tools/llvm-readobj/ELFDumper.cpp
index fcadf73110e..047b463582c 100644
--- a/llvm/tools/llvm-readobj/ELFDumper.cpp
+++ b/llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -1346,6 +1346,7 @@ static const char *getElfMipsOptionsOdkType(unsigned Odk) {
 
 template <typename ELFT>
 void ELFDumper<ELFT>::loadDynamicTable(const ELFFile<ELFT> *Obj) {
+  // Try to locate the PT_DYNAMIC header.
   const Elf_Phdr *DynamicPhdr = nullptr;
   for (const Elf_Phdr &Phdr : unwrapOrError(Obj->program_headers())) {
     if (Phdr.p_type != ELF::PT_DYNAMIC)
@@ -1354,11 +1355,6 @@ void ELFDumper<ELFT>::loadDynamicTable(const ELFFile<ELFT> *Obj) {
     break;
   }
 
-  // We do not want to dump dynamic section if we have no PT_DYNAMIC header.
-  // This matches GNU's behavior.
-  if (!DynamicPhdr)
-    return;
-
   // Try to locate the .dynamic section in the sections header table.
   const Elf_Shdr *DynamicSec = nullptr;
   for (const Elf_Shdr &Sec : unwrapOrError(Obj->sections())) {
@@ -1373,9 +1369,16 @@ void ELFDumper<ELFT>::loadDynamicTable(const ELFFile<ELFT> *Obj) {
   // Ignore sh_entsize and use the expected value for entry size explicitly.
   // This allows us to dump the dynamic sections with a broken sh_entsize
   // field.
-  if (DynamicSec)
+  if (DynamicSec) {
     DynamicTable = checkDRI({ObjF->getELFFile()->base() + DynamicSec->sh_offset,
                              DynamicSec->sh_size, sizeof(Elf_Dyn)});
+    parseDynamicTable();
+  }
+
+  // If we have a PT_DYNAMIC header, we will either check the found dynamic
+  // section or take the dynamic table data directly from the header.
+  if (!DynamicPhdr)
+    return;
 
   if (DynamicPhdr->p_offset + DynamicPhdr->p_filesz >
       ObjF->getMemoryBufferRef().getBufferSize())
@@ -1389,7 +1392,6 @@ void ELFDumper<ELFT>::loadDynamicTable(const ELFFile<ELFT> *Obj) {
   }
 
   StringRef Name = unwrapOrError(Obj->getSectionName(DynamicSec));
-
   if (DynamicSec->sh_addr + DynamicSec->sh_size >
           DynamicPhdr->p_vaddr + DynamicPhdr->p_memsz ||
       DynamicSec->sh_addr < DynamicPhdr->p_vaddr)
@@ -1401,8 +1403,6 @@ void ELFDumper<ELFT>::loadDynamicTable(const ELFFile<ELFT> *Obj) {
     reportWarning("The SHT_DYNAMIC section '" + Name +
                   "' is not at the start of "
                   "PT_DYNAMIC segment");
-
-  parseDynamicTable();
 }
 
 template <typename ELFT>
@@ -1460,11 +1460,71 @@ ELFDumper<ELFT>::ELFDumper(const object::ELFObjectFile<ELFT> *ObjF,
     ELFDumperStyle.reset(new LLVMStyle<ELFT>(Writer, this));
 }
 
+static const char *getTypeString(unsigned Arch, uint64_t Type) {
+#define DYNAMIC_TAG(n, v)
+  switch (Arch) {
+  case EM_HEXAGON:
+    switch (Type) {
+#define HEXAGON_DYNAMIC_TAG(name, value)                                       \
+  case DT_##name:                                                              \
+    return #name;
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef HEXAGON_DYNAMIC_TAG
+    }
+    break;
+
+  case EM_MIPS:
+    switch (Type) {
+#define MIPS_DYNAMIC_TAG(name, value)                                          \
+  case DT_##name:                                                              \
+    return #name;
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef MIPS_DYNAMIC_TAG
+    }
+    break;
+
+  case EM_PPC64:
+    switch (Type) {
+#define PPC64_DYNAMIC_TAG(name, value)                                         \
+  case DT_##name:                                                              \
+    return #name;
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef PPC64_DYNAMIC_TAG
+    }
+    break;
+  }
+#undef DYNAMIC_TAG
+  switch (Type) {
+// Now handle all dynamic tags except the architecture specific ones
+#define MIPS_DYNAMIC_TAG(name, value)
+#define HEXAGON_DYNAMIC_TAG(name, value)
+#define PPC64_DYNAMIC_TAG(name, value)
+// Also ignore marker tags such as DT_HIOS (maps to DT_VERNEEDNUM), etc.
+#define DYNAMIC_TAG_MARKER(name, value)
+#define DYNAMIC_TAG(name, value)                                               \
+  case DT_##name:                                                              \
+    return #name;
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef DYNAMIC_TAG
+#undef MIPS_DYNAMIC_TAG
+#undef HEXAGON_DYNAMIC_TAG
+#undef PPC64_DYNAMIC_TAG
+#undef DYNAMIC_TAG_MARKER
+  default:
+    return "unknown";
+  }
+}
+
 template <typename ELFT> void ELFDumper<ELFT>::parseDynamicTable() {
-  auto toMappedAddr = [&](uint64_t VAddr) -> const uint8_t * {
+  auto toMappedAddr = [&](uint64_t Tag, uint64_t VAddr) -> const uint8_t * {
     auto MappedAddrOrError = ObjF->getELFFile()->toMappedAddr(VAddr);
-    if (!MappedAddrOrError)
-      report_fatal_error(MappedAddrOrError.takeError());
+    if (!MappedAddrOrError) {
+      reportWarning("Unable to parse DT_" +
+                    Twine(getTypeString(
+                        ObjF->getELFFile()->getHeader()->e_machine, Tag)) +
+                    ": " + llvm::toString(MappedAddrOrError.takeError()));
+      return nullptr;
+    }
     return MappedAddrOrError.get();
   };
 
@@ -1474,26 +1534,26 @@ template <typename ELFT> void ELFDumper<ELFT>::parseDynamicTable() {
   for (const Elf_Dyn &Dyn : dynamic_table()) {
     switch (Dyn.d_tag) {
     case ELF::DT_HASH:
-      HashTable =
-          reinterpret_cast<const Elf_Hash *>(toMappedAddr(Dyn.getPtr()));
+      HashTable = reinterpret_cast<const Elf_Hash *>(
+          toMappedAddr(Dyn.getTag(), Dyn.getPtr()));
       break;
     case ELF::DT_GNU_HASH:
-      GnuHashTable =
-          reinterpret_cast<const Elf_GnuHash *>(toMappedAddr(Dyn.getPtr()));
+      GnuHashTable = reinterpret_cast<const Elf_GnuHash *>(
+          toMappedAddr(Dyn.getTag(), Dyn.getPtr()));
       break;
     case ELF::DT_STRTAB:
-      StringTableBegin =
-          reinterpret_cast<const char *>(toMappedAddr(Dyn.getPtr()));
+      StringTableBegin = reinterpret_cast<const char *>(
+          toMappedAddr(Dyn.getTag(), Dyn.getPtr()));
       break;
     case ELF::DT_STRSZ:
       StringTableSize = Dyn.getVal();
       break;
     case ELF::DT_SYMTAB:
-      DynSymRegion.Addr = toMappedAddr(Dyn.getPtr());
+      DynSymRegion.Addr = toMappedAddr(Dyn.getTag(), Dyn.getPtr());
       DynSymRegion.EntSize = sizeof(Elf_Sym);
       break;
     case ELF::DT_RELA:
-      DynRelaRegion.Addr = toMappedAddr(Dyn.getPtr());
+      DynRelaRegion.Addr = toMappedAddr(Dyn.getTag(), Dyn.getPtr());
       break;
     case ELF::DT_RELASZ:
       DynRelaRegion.Size = Dyn.getVal();
@@ -1505,7 +1565,7 @@ template <typename ELFT> void ELFDumper<ELFT>::parseDynamicTable() {
       SONameOffset = Dyn.getVal();
       break;
     case ELF::DT_REL:
-      DynRelRegion.Addr = toMappedAddr(Dyn.getPtr());
+      DynRelRegion.Addr = toMappedAddr(Dyn.getTag(), Dyn.getPtr());
       break;
     case ELF::DT_RELSZ:
       DynRelRegion.Size = Dyn.getVal();
@@ -1515,7 +1575,7 @@ template <typename ELFT> void ELFDumper<ELFT>::parseDynamicTable() {
       break;
     case ELF::DT_RELR:
     case ELF::DT_ANDROID_RELR:
-      DynRelrRegion.Addr = toMappedAddr(Dyn.getPtr());
+      DynRelrRegion.Addr = toMappedAddr(Dyn.getTag(), Dyn.getPtr());
       break;
     case ELF::DT_RELRSZ:
     case ELF::DT_ANDROID_RELRSZ:
@@ -1535,7 +1595,7 @@ template <typename ELFT> void ELFDumper<ELFT>::parseDynamicTable() {
                     Twine((uint64_t)Dyn.getVal()));
       break;
     case ELF::DT_JMPREL:
-      DynPLTRelRegion.Addr = toMappedAddr(Dyn.getPtr());
+      DynPLTRelRegion.Addr = toMappedAddr(Dyn.getTag(), Dyn.getPtr());
       break;
     case ELF::DT_PLTRELSZ:
       DynPLTRelRegion.Size = Dyn.getVal();
@@ -1627,61 +1687,6 @@ template <class ELFT> void ELFDumper<ELFT>::printELFLinkerOptions() {
   ELFDumperStyle->printELFLinkerOptions(ObjF->getELFFile());
 }
 
-static const char *getTypeString(unsigned Arch, uint64_t Type) {
-#define DYNAMIC_TAG(n, v)
-  switch (Arch) {
-  case EM_HEXAGON:
-    switch (Type) {
-#define HEXAGON_DYNAMIC_TAG(name, value)                                       \
-    case DT_##name:                                                            \
-      return #name;
-#include "llvm/BinaryFormat/DynamicTags.def"
-#undef HEXAGON_DYNAMIC_TAG
-    }
-    break;
-
-  case EM_MIPS:
-    switch (Type) {
-#define MIPS_DYNAMIC_TAG(name, value)                                          \
-    case DT_##name:                                                            \
-      return #name;
-#include "llvm/BinaryFormat/DynamicTags.def"
-#undef MIPS_DYNAMIC_TAG
-    }
-    break;
-
-  case EM_PPC64:
-    switch(Type) {
-#define PPC64_DYNAMIC_TAG(name, value)                                         \
-    case DT_##name:                                                            \
-      return #name;
-#include "llvm/BinaryFormat/DynamicTags.def"
-#undef PPC64_DYNAMIC_TAG
-    }
-    break;
-  }
-#undef DYNAMIC_TAG
-  switch (Type) {
-// Now handle all dynamic tags except the architecture specific ones
-#define MIPS_DYNAMIC_TAG(name, value)
-#define HEXAGON_DYNAMIC_TAG(name, value)
-#define PPC64_DYNAMIC_TAG(name, value)
-// Also ignore marker tags such as DT_HIOS (maps to DT_VERNEEDNUM), etc.
-#define DYNAMIC_TAG_MARKER(name, value)
-#define DYNAMIC_TAG(name, value)                                               \
-  case DT_##name:                                                              \
-    return #name;
-#include "llvm/BinaryFormat/DynamicTags.def"
-#undef DYNAMIC_TAG
-#undef MIPS_DYNAMIC_TAG
-#undef HEXAGON_DYNAMIC_TAG
-#undef PPC64_DYNAMIC_TAG
-#undef DYNAMIC_TAG_MARKER
-  default:
-    return "unknown";
-  }
-}
-
 #define LLVM_READOBJ_DT_FLAG_ENT(prefix, enum)                                 \
   { #enum, prefix##_##enum }