Fix for Bug 25338

Summary:
The issue arises because LLDB is not
able to read the vdso library correctly.
The fix adds memory allocation callbacks
to allocate sufficient memory in case the
requested offsets don't fit in the memory
buffer allocated for the ELF.

Reviewers: lldb-commits, clayborg, deepak2427, ovyalov, labath, tberghammer

Differential Revision: http://reviews.llvm.org/D16107

llvm-svn: 258122

1 files changed, 52 insertions, 12 deletions

diff --git a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
index 9f2cd4f3fd1..67be1461d4d 100644
--- a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
+++ b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
@@ -729,7 +729,10 @@ ObjectFileELF::GetModuleSpecifications (const lldb_private::FileSpec& file,
                     SectionHeaderColl section_headers;
                     lldb_private::UUID &uuid = spec.GetUUID();
 
-                    GetSectionHeaderInfo(section_headers, data, header, uuid, gnu_debuglink_file, gnu_debuglink_crc, spec.GetArchitecture ());
+                    using namespace std::placeholders;
+                    const SetDataFunction set_data = std::bind(&ObjectFileELF::SetData, std::cref(data), _1, _2, _3);
+                    GetSectionHeaderInfo(section_headers, set_data, header, uuid, gnu_debuglink_file, gnu_debuglink_crc, spec.GetArchitecture ());
+
 
                     llvm::Triple &spec_triple = spec.GetArchitecture ().GetTriple ();
 
@@ -759,7 +762,7 @@ ObjectFileELF::GetModuleSpecifications (const lldb_private::FileSpec& file,
                                     data.SetData(data_sp);
                                 }
                                 ProgramHeaderColl program_headers;
-                                GetProgramHeaderInfo(program_headers, data, header);
+                                GetProgramHeaderInfo(program_headers, set_data, header);
 
                                 size_t segment_data_end = 0;
                                 for (ProgramHeaderCollConstIter I = program_headers.begin();
@@ -1256,7 +1259,7 @@ ObjectFileELF::ParseDependentModules()
 //----------------------------------------------------------------------
 size_t
 ObjectFileELF::GetProgramHeaderInfo(ProgramHeaderColl &program_headers,
-                                    DataExtractor &object_data,
+                                    const SetDataFunction &set_data,
                                     const ELFHeader &header)
 {
     // We have already parsed the program headers
@@ -1274,7 +1277,7 @@ ObjectFileELF::GetProgramHeaderInfo(ProgramHeaderColl &program_headers,
     const size_t ph_size = header.e_phnum * header.e_phentsize;
     const elf_off ph_offset = header.e_phoff;
     DataExtractor data;
-    if (data.SetData(object_data, ph_offset, ph_size) != ph_size)
+    if (set_data(data, ph_offset, ph_size) != ph_size)
         return 0;
 
     uint32_t idx;
@@ -1298,7 +1301,10 @@ ObjectFileELF::GetProgramHeaderInfo(ProgramHeaderColl &program_headers,
 size_t
 ObjectFileELF::ParseProgramHeaders()
 {
-    return GetProgramHeaderInfo(m_program_headers, m_data, m_header);
+    using namespace std::placeholders;
+    return GetProgramHeaderInfo(m_program_headers,
+                                std::bind(&ObjectFileELF::SetDataWithReadMemoryFallback, this, _1, _2, _3),
+                                m_header);
 }
 
 lldb_private::Error
@@ -1511,7 +1517,7 @@ ObjectFileELF::RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, l
 //----------------------------------------------------------------------
 size_t
 ObjectFileELF::GetSectionHeaderInfo(SectionHeaderColl &section_headers,
-                                    lldb_private::DataExtractor &object_data,
+                                    const SetDataFunction &set_data,
                                     const elf::ELFHeader &header,
                                     lldb_private::UUID &uuid,
                                     std::string &gnu_debuglink_file,
@@ -1569,7 +1575,7 @@ ObjectFileELF::GetSectionHeaderInfo(SectionHeaderColl &section_headers,
     const size_t sh_size = header.e_shnum * header.e_shentsize;
     const elf_off sh_offset = header.e_shoff;
     DataExtractor sh_data;
-    if (sh_data.SetData (object_data, sh_offset, sh_size) != sh_size)
+    if (set_data (sh_data, sh_offset, sh_size) != sh_size)
         return 0;
 
     uint32_t idx;
@@ -1590,7 +1596,7 @@ ObjectFileELF::GetSectionHeaderInfo(SectionHeaderColl &section_headers,
         const Elf64_Off offset = sheader.sh_offset;
         lldb_private::DataExtractor shstr_data;
 
-        if (shstr_data.SetData (object_data, offset, byte_size) == byte_size)
+        if (set_data (shstr_data, offset, byte_size) == byte_size)
         {
             for (SectionHeaderCollIter I = section_headers.begin();
                  I != section_headers.end(); ++I)
@@ -1610,7 +1616,7 @@ ObjectFileELF::GetSectionHeaderInfo(SectionHeaderColl &section_headers,
                     if (sheader.sh_type == SHT_MIPS_ABIFLAGS)
                     {
 
-                        if (section_size && (data.SetData (object_data, sheader.sh_offset, section_size) == section_size))
+                        if (section_size && (set_data (data, sheader.sh_offset, section_size) == section_size))
                         {
                             lldb::offset_t ase_offset = 12; // MIPS ABI Flags Version: 0
                             arch_flags |= data.GetU32 (&ase_offset);
@@ -1631,7 +1637,7 @@ ObjectFileELF::GetSectionHeaderInfo(SectionHeaderColl &section_headers,
                 if (name == g_sect_name_gnu_debuglink)
                 {
                     DataExtractor data;
-                    if (section_size && (data.SetData (object_data, sheader.sh_offset, section_size) == section_size))
+                    if (section_size && (set_data (data, sheader.sh_offset, section_size) == section_size))
                     {
                         lldb::offset_t gnu_debuglink_offset = 0;
                         gnu_debuglink_file = data.GetCStr (&gnu_debuglink_offset);
@@ -1653,7 +1659,7 @@ ObjectFileELF::GetSectionHeaderInfo(SectionHeaderColl &section_headers,
                 {
                     // Allow notes to refine module info.
                     DataExtractor data;
-                    if (section_size && (data.SetData (object_data, sheader.sh_offset, section_size) == section_size))
+                    if (section_size && (set_data (data, sheader.sh_offset, section_size) == section_size))
                     {
                         Error error = RefineModuleDetailsFromNote (data, arch_spec, uuid);
                         if (error.Fail ())
@@ -1719,7 +1725,41 @@ ObjectFileELF::StripLinkerSymbolAnnotations(llvm::StringRef symbol_name) const
 size_t
 ObjectFileELF::ParseSectionHeaders()
 {
-    return GetSectionHeaderInfo(m_section_headers, m_data, m_header, m_uuid, m_gnu_debuglink_file, m_gnu_debuglink_crc, m_arch_spec);
+    using namespace std::placeholders;
+
+    return GetSectionHeaderInfo(m_section_headers,
+                                std::bind(&ObjectFileELF::SetDataWithReadMemoryFallback, this, _1, _2, _3),
+                                m_header,
+                                m_uuid,
+                                m_gnu_debuglink_file,
+                                m_gnu_debuglink_crc,
+                                m_arch_spec);
+}
+
+lldb::offset_t
+ObjectFileELF::SetData(const lldb_private::DataExtractor &src, lldb_private::DataExtractor &dst, lldb::offset_t offset, lldb::offset_t length)
+{
+    return dst.SetData(src, offset, length);
+}
+
+lldb::offset_t
+ObjectFileELF::SetDataWithReadMemoryFallback(lldb_private::DataExtractor &dst, lldb::offset_t offset, lldb::offset_t length)
+{
+    if (offset + length <= m_data.GetByteSize())
+        return dst.SetData(m_data, offset, length);
+
+    const auto process_sp = m_process_wp.lock();
+    if (process_sp != nullptr)
+    {
+        addr_t file_size = offset + length;
+
+        DataBufferSP data_sp = ReadMemory(process_sp, m_memory_addr, file_size);
+        if (!data_sp)
+            return false;
+        m_data.SetData(data_sp, 0, file_size);
+    }
+
+    return dst.SetData(m_data, offset, length);
 }
 
 const ObjectFileELF::ELFSectionHeaderInfo *