caio/clang-p2996
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Make core files not crash when you load a core file into LLDB with just "lldb -c core".

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To do this I added a few new ways to determine the OS from PT_NOTE notes in the ELF file:
1 - Look for "LINUX" notes which indicate "linux" should be the OS
2 - Look through the "CORE" notes with NT_FILE as the type and sniff data from the paths listed in this section. On Ubuntu they contain "/lib/x86_64-linux-gnu" which has the triple and allows us to set "linux" as the OS in the architecture returned from ObjectFileELF::GetArchitecture(). 

Setting the OS correctly allows us to get the triple correct so we can extract registers without asserting and killing LLDB.

Also use the data from the NT_FILE to set the main executable if one isn't set in ProcessElfCore::DoLoadCore().
 

llvm-svn: 251537
This commit is contained in:
Greg Clayton
2015-10-28 18:04:38 +00:00
parent 06f4e43d29
commit b704b69e0b
4 changed files with 162 additions and 24 deletions
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122
lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
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@@ -49,6 +49,8 @@ const char *const LLDB_NT_OWNER_GNU = "GNU";
const char *const LLDB_NT_OWNER_NETBSD = "NetBSD";
const char *const LLDB_NT_OWNER_CSR = "csr";
const char *const LLDB_NT_OWNER_ANDROID = "Android";
const char *const LLDB_NT_OWNER_CORE = "CORE";
const char *const LLDB_NT_OWNER_LINUX = "LINUX";
// ELF note type definitions
const elf_word LLDB_NT_FREEBSD_ABI_TAG = 0x01;
@@ -67,6 +69,41 @@ const elf_word LLDB_NT_GNU_ABI_OS_LINUX = 0x00;
const elf_word LLDB_NT_GNU_ABI_OS_HURD = 0x01;
const elf_word LLDB_NT_GNU_ABI_OS_SOLARIS = 0x02;
// LLDB_NT_OWNER_CORE and LLDB_NT_OWNER_LINUX note contants
#define NT_PRSTATUS 1
#define NT_PRFPREG 2
#define NT_PRPSINFO 3
#define NT_TASKSTRUCT 4
#define NT_AUXV 6
#define NT_SIGINFO 0x53494749
#define NT_FILE 0x46494c45
#define NT_PRXFPREG 0x46e62b7f
#define NT_PPC_VMX 0x100
#define NT_PPC_SPE 0x101
#define NT_PPC_VSX 0x102
#define NT_386_TLS 0x200
#define NT_386_IOPERM 0x201
#define NT_X86_XSTATE 0x202
#define NT_S390_HIGH_GPRS 0x300
#define NT_S390_TIMER 0x301
#define NT_S390_TODCMP 0x302
#define NT_S390_TODPREG 0x303
#define NT_S390_CTRS 0x304
#define NT_S390_PREFIX 0x305
#define NT_S390_LAST_BREAK 0x306
#define NT_S390_SYSTEM_CALL 0x307
#define NT_S390_TDB 0x308
#define NT_S390_VXRS_LOW 0x309
#define NT_S390_VXRS_HIGH 0x30a
#define NT_ARM_VFP 0x400
#define NT_ARM_TLS 0x401
#define NT_ARM_HW_BREAK 0x402
#define NT_ARM_HW_WATCH 0x403
#define NT_ARM_SYSTEM_CALL 0x404
#define NT_METAG_CBUF 0x500
#define NT_METAG_RPIPE 0x501
#define NT_METAG_TLS 0x502
//===----------------------------------------------------------------------===//
/// @class ELFRelocation
/// @brief Generic wrapper for ELFRel and ELFRela.
@@ -1273,6 +1310,7 @@ ObjectFileELF::RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, l
while (true)
{
// Parse the note header. If this fails, bail out.
const lldb::offset_t note_offset = offset;
ELFNote note = ELFNote();
if (!note.Parse(data, &offset))
{
@@ -1280,11 +1318,6 @@ ObjectFileELF::RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, l
return error;
}
// If a tag processor handles the tag, it should set processed to true, and
// the loop will assume the tag processing has moved entirely past the note's payload.
// Otherwise, leave it false and the end of the loop will handle the offset properly.
bool processed = false;
if (log)
log->Printf ("ObjectFileELF::%s parsing note name='%s', type=%" PRIu32, __FUNCTION__, note.n_name.c_str (), note.n_type);
@@ -1293,9 +1326,6 @@ ObjectFileELF::RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, l
(note.n_type == LLDB_NT_FREEBSD_ABI_TAG) &&
(note.n_descsz == LLDB_NT_FREEBSD_ABI_SIZE))
{
// We'll consume the payload below.
processed = true;
// Pull out the min version info.
uint32_t version_info;
if (data.GetU32 (&offset, &version_info, 1) == nullptr)
@@ -1326,9 +1356,6 @@ ObjectFileELF::RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, l
case LLDB_NT_GNU_ABI_TAG:
if (note.n_descsz == LLDB_NT_GNU_ABI_SIZE)
{
// We'll consume the payload below.
processed = true;
// Pull out the min OS version supporting the ABI.
uint32_t version_info[4];
if (data.GetU32 (&offset, &version_info[0], note.n_descsz / 4) == nullptr)
@@ -1371,9 +1398,6 @@ ObjectFileELF::RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, l
// Only bother processing this if we don't already have the uuid set.
if (!uuid.IsValid())
{
// We'll consume the payload below.
processed = true;
// 16 bytes is UUID|MD5, 20 bytes is SHA1
if ((note.n_descsz == 16 || note.n_descsz == 20))
{
@@ -1396,10 +1420,6 @@ ObjectFileELF::RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, l
(note.n_type == LLDB_NT_NETBSD_ABI_TAG) &&
(note.n_descsz == LLDB_NT_NETBSD_ABI_SIZE))
{
// We'll consume the payload below.
processed = true;
// Pull out the min version info.
uint32_t version_info;
if (data.GetU32 (&offset, &version_info, 1) == nullptr)
@@ -1419,8 +1439,6 @@ ObjectFileELF::RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, l
else if ((note.n_type == LLDB_NT_GNU_ABI_TAG) &&
(note.n_name == LLDB_NT_OWNER_CSR))
{
// We'll consume the payload below.
processed = true;
arch_spec.GetTriple().setOS(llvm::Triple::OSType::UnknownOS);
arch_spec.GetTriple().setVendor(llvm::Triple::VendorType::CSR);
@@ -1438,9 +1456,48 @@ ObjectFileELF::RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, l
arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
arch_spec.GetTriple().setEnvironment(llvm::Triple::EnvironmentType::Android);
}
else if (note.n_name == LLDB_NT_OWNER_LINUX)
{
// This is sometimes found in core files and usually contains extended register info
arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
}
else if (note.n_name == LLDB_NT_OWNER_CORE)
{
// Parse the NT_FILE to look for stuff in paths to shared libraries
// As the contents look like:
// count = 0x000000000000000a (10)
// page_size = 0x0000000000001000 (4096)
// Index start end file_ofs path
// ===== ------------------ ------------------ ------------------ -------------------------------------
// [ 0] 0x0000000000400000 0x0000000000401000 0x0000000000000000 /tmp/a.out
// [ 1] 0x0000000000600000 0x0000000000601000 0x0000000000000000 /tmp/a.out
// [ 2] 0x0000000000601000 0x0000000000602000 0x0000000000000001 /tmp/a.out
// [ 3] 0x00007fa79c9ed000 0x00007fa79cba8000 0x0000000000000000 /lib/x86_64-linux-gnu/libc-2.19.so
// [ 4] 0x00007fa79cba8000 0x00007fa79cda7000 0x00000000000001bb /lib/x86_64-linux-gnu/libc-2.19.so
// [ 5] 0x00007fa79cda7000 0x00007fa79cdab000 0x00000000000001ba /lib/x86_64-linux-gnu/libc-2.19.so
// [ 6] 0x00007fa79cdab000 0x00007fa79cdad000 0x00000000000001be /lib/x86_64-linux-gnu/libc-2.19.so
// [ 7] 0x00007fa79cdb2000 0x00007fa79cdd5000 0x0000000000000000 /lib/x86_64-linux-gnu/ld-2.19.so
// [ 8] 0x00007fa79cfd4000 0x00007fa79cfd5000 0x0000000000000022 /lib/x86_64-linux-gnu/ld-2.19.so
// [ 9] 0x00007fa79cfd5000 0x00007fa79cfd6000 0x0000000000000023 /lib/x86_64-linux-gnu/ld-2.19.so
if (note.n_type == NT_FILE)
{
uint64_t count = data.GetU64(&offset);
offset += 8 + 3*8*count; // Skip page size and all start/end/file_ofs
for (size_t i=0; i<count; ++i)
{
llvm::StringRef path(data.GetCStr(&offset));
if (path.startswith("/lib/x86_64-linux-gnu"))
{
arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
break;
}
}
}
}
if (!processed)
offset += llvm::RoundUpToAlignment(note.n_descsz, 4);
// Calculate the offset of the next note just in case "offset" has been used
// to poke at the contents of the note data
offset = note_offset + note.GetByteSize();
}
return error;
@@ -3147,6 +3204,27 @@ ObjectFileELF::GetArchitecture (ArchSpec &arch)
ParseSectionHeaders();
}
if (CalculateType() == eTypeCoreFile && m_arch_spec.TripleOSIsUnspecifiedUnknown())
{
// Core files don't have section headers yet they have PT_NOTE program headers
// that might shed more light on the architecture
if (ParseProgramHeaders())
{
for (size_t i = 0, count = GetProgramHeaderCount(); i < count; ++i)
{
const elf::ELFProgramHeader* header = GetProgramHeaderByIndex(i);
if (header && header->p_type == PT_NOTE && header->p_offset != 0 && header->p_filesz > 0)
{
DataExtractor data;
if (data.SetData (m_data, header->p_offset, header->p_filesz) == header->p_filesz)
{
lldb_private::UUID uuid;
RefineModuleDetailsFromNote (data, m_arch_spec, uuid);
}
}
}
}
}
arch = m_arch_spec;
return true;
}