clang: Fix llvm-objdump crash on aarch64/musl

Signed-off-by: Khem Raj <raj.khem@gmail.com>

2 files changed, 158 insertions, 0 deletions

diff --git a/recipes-devtools/clang/clang/0001-llvm-objdump-Change-printSymbolVersionDependency-to-.patch b/recipes-devtools/clang/clang/0001-llvm-objdump-Change-printSymbolVersionDependency-to-.patch
new file mode 100644
index 0000000..6bcc951
--- /dev/null
+++ b/recipes-devtools/clang/clang/0001-llvm-objdump-Change-printSymbolVersionDependency-to-.patch
@@ -0,0 +1,157 @@
+From 1a4646b30f627ef92c1de6cd65f6d0cc87b0ef11 Mon Sep 17 00:00:00 2001
+From: Khem Raj <raj.khem@gmail.com>
+Date: Tue, 13 Sep 2022 00:24:10 -0700
+Subject: [PATCH] [llvm-objdump] Change printSymbolVersionDependency to use
+ ELFFile API
+
+When .gnu.version_r is empty (allowed by readelf but warned by objdump),
+llvm-objdump -p may decode the next section as .gnu.version_r and may crash due
+to out-of-bounds C string reference. ELFFile<ELFT>::getVersionDependencies
+handles 0-entry .gnu.version_r gracefully. Just use it.
+
+Fix https://github.com/llvm/llvm-project/issues/57707
+
+Upstream-Status: Submitted [https://reviews.llvm.org/D133751]
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+ llvm/include/llvm/Object/ELF.h                |  2 +-
+ .../llvm-objdump/ELF/verneed-invalid.test     | 24 ++++++++++++
+ llvm/test/tools/llvm-objdump/ELF/verneed.test | 20 ++++++++++
+ llvm/tools/llvm-objdump/ELFDump.cpp           | 39 ++++++++++---------
+ 4 files changed, 65 insertions(+), 20 deletions(-)
+ create mode 100644 llvm/test/tools/llvm-objdump/ELF/verneed-invalid.test
+
+diff --git a/llvm/include/llvm/Object/ELF.h b/llvm/include/llvm/Object/ELF.h
+index 16c9a1461f8d..8b8a574be090 100644
+--- a/llvm/include/llvm/Object/ELF.h
++++ b/llvm/include/llvm/Object/ELF.h
+@@ -1038,7 +1038,7 @@ ELFFile<ELFT>::getVersionDependencies(const Elf_Shdr &Sec,
+     VN.Offset = VerneedBuf - Start;
+ 
+     if (Verneed->vn_file < StrTab.size())
+-      VN.File = std::string(StrTab.drop_front(Verneed->vn_file));
++      VN.File = std::string(StrTab.data() + Verneed->vn_file);
+     else
+       VN.File = ("<corrupt vn_file: " + Twine(Verneed->vn_file) + ">").str();
+ 
+diff --git a/llvm/test/tools/llvm-objdump/ELF/verneed-invalid.test b/llvm/test/tools/llvm-objdump/ELF/verneed-invalid.test
+new file mode 100644
+index 000000000000..4756a59ed107
+--- /dev/null
++++ b/llvm/test/tools/llvm-objdump/ELF/verneed-invalid.test
+@@ -0,0 +1,24 @@
++# RUN: yaml2obj %s -o %t
++# RUN: llvm-objdump -p %t 2>&1 | FileCheck %s --check-prefix=BROKEN-AUX -DFILE=%t
++
++# BROKEN-AUX:      Version References:
++# BROKEN-AUX-NEXT: warning: '[[FILE]]': invalid SHT_GNU_verneed section with index 2: found a misaligned auxiliary entry at offset 0x11
++
++--- !ELF
++FileHeader:
++  Class: ELFCLASS64
++  Data:  ELFDATA2LSB
++  Type:  ET_EXEC
++Sections:
++  - Name:    .gnu.version
++    Type:    SHT_GNU_versym
++    Flags:   [ SHF_ALLOC ]
++    Entries: [ 2 ]
++  - Name:         .gnu.version_r
++    Type:         SHT_GNU_verneed
++    Flags:        [ SHF_ALLOC ]
++    Info:         1
++    AddressAlign: 4
++## The byte offset to the auxiliary entry is 0x11, i.e. it is not correctly aligned in memory.
++    Content: "0100010001000000110000000000000000000000"
++DynamicSymbols: []
+diff --git a/llvm/test/tools/llvm-objdump/ELF/verneed.test b/llvm/test/tools/llvm-objdump/ELF/verneed.test
+index 57e856e542ad..7b38ef95fd41 100644
+--- a/llvm/test/tools/llvm-objdump/ELF/verneed.test
++++ b/llvm/test/tools/llvm-objdump/ELF/verneed.test
+@@ -46,3 +46,23 @@ Sections:
+ DynamicSymbols:
+   - Name:    f1
+     Binding: STB_GLOBAL
++
++# RUN: yaml2obj --docnum=2 %s -o %t.empty
++# RUN: llvm-objdump -p %t.empty 2>&1 | FileCheck %s --check-prefix=EMPTY --implicit-check-not=warning:
++
++# EMPTY:     Version References:
++# EMPTY-NOT: {{.}}
++
++--- !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 ]
++DynamicSymbols:
++  - Name:    f1
++    Binding: STB_GLOBAL
+diff --git a/llvm/tools/llvm-objdump/ELFDump.cpp b/llvm/tools/llvm-objdump/ELFDump.cpp
+index ca73dafe2b8e..61676b4323d2 100644
+--- a/llvm/tools/llvm-objdump/ELFDump.cpp
++++ b/llvm/tools/llvm-objdump/ELFDump.cpp
+@@ -282,27 +282,28 @@ static void printProgramHeaders(const ELFFile<ELFT> &Obj, StringRef FileName) {
+ }
+ 
+ template <class ELFT>
+-static void printSymbolVersionDependency(ArrayRef<uint8_t> Contents,
+-                                         StringRef StrTab) {
++static void printSymbolVersionDependency(StringRef FileName,
++                                         const ELFFile<ELFT> &Obj,
++                                         const typename ELFT::Shdr &Sec) {
+   outs() << "\nVersion References:\n";
+ 
+-  const uint8_t *Buf = Contents.data();
+-  while (Buf) {
+-    auto *Verneed = reinterpret_cast<const typename ELFT::Verneed *>(Buf);
+-    outs() << "  required from "
+-           << StringRef(StrTab.drop_front(Verneed->vn_file).data()) << ":\n";
++  auto WarningHandler = [&](const Twine &Msg) {
++    reportWarning(Msg, FileName);
++    return Error::success();
++  };
++  Expected<std::vector<VerNeed>> V =
++      Obj.getVersionDependencies(Sec, WarningHandler);
++  if (!V) {
++    reportWarning(toString(V.takeError()), FileName);
++    return;
++  }
+ 
+-    const uint8_t *BufAux = Buf + Verneed->vn_aux;
+-    while (BufAux) {
+-      auto *Vernaux = reinterpret_cast<const typename ELFT::Vernaux *>(BufAux);
+-      outs() << "    "
+-             << format("0x%08" PRIx32 " ", (uint32_t)Vernaux->vna_hash)
+-             << format("0x%02" PRIx16 " ", (uint16_t)Vernaux->vna_flags)
+-             << format("%02" PRIu16 " ", (uint16_t)Vernaux->vna_other)
+-             << StringRef(StrTab.drop_front(Vernaux->vna_name).data()) << '\n';
+-      BufAux = Vernaux->vna_next ? BufAux + Vernaux->vna_next : nullptr;
+-    }
+-    Buf = Verneed->vn_next ? Buf + Verneed->vn_next : nullptr;
++  raw_fd_ostream &OS = outs();
++  for (const VerNeed &VN : *V) {
++    OS << "  required from " << VN.File << ":\n";
++    for (const VernAux &Aux : VN.AuxV)
++      OS << format("    0x%08x 0x%02x %02u %s\n", Aux.Hash, Aux.Flags,
++                   Aux.Other, Aux.Name.c_str());
+   }
+ }
+ 
+@@ -355,7 +356,7 @@ static void printSymbolVersionInfo(const ELFFile<ELFT> &Elf,
+     StringRef StrTab = unwrapOrError(Elf.getStringTable(*StrTabSec), FileName);
+ 
+     if (Shdr.sh_type == ELF::SHT_GNU_verneed)
+-      printSymbolVersionDependency<ELFT>(Contents, StrTab);
++      printSymbolVersionDependency<ELFT>(FileName, Elf, Shdr);
+     else
+       printSymbolVersionDefinition<ELFT>(Shdr, Contents, StrTab);
+   }
+-- 
+2.37.3
+
diff --git a/recipes-devtools/clang/common.inc b/recipes-devtools/clang/common.inc
index 3a4d504..7e6b1ef 100644
--- a/recipes-devtools/clang/common.inc
+++ b/recipes-devtools/clang/common.inc
@@ -45,6 +45,7 @@ SRC_URI = "\
     file://0033-compiler-rt-Enable-__int128-for-ppc32.patch \
     file://0034-llvm-Do-not-use-cmake-infra-to-detect-libzstd.patch \
     file://0035-Revert-MIPS-compiler-rt-Fix-stat-struct-s-size-for-O.patch \
+    file://0001-llvm-objdump-Change-printSymbolVersionDependency-to-.patch \
     "
 # Fallback to no-PIE if not set
 GCCPIE ??= ""