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llvm-project/lldb/source/Symbol/CompactUnwindInfo.cpp

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//===-- CompactUnwindInfo.cpp -----------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// C Includes
// C++ Includes
#include <algorithm>
#include "lldb/Core/ArchSpec.h"
#include "lldb/Core/DataBufferHeap.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/Section.h"
#include "lldb/Core/Section.h"
#include "lldb/Core/StreamString.h"
#include "lldb/Symbol/CompactUnwindInfo.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Symbol/UnwindPlan.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/Target.h"
#include "llvm/Support/MathExtras.h"
using namespace lldb;
using namespace lldb_private;
namespace lldb_private {
// Constants from <mach-o/compact_unwind_encoding.h>
FLAGS_ANONYMOUS_ENUM()
{
UNWIND_IS_NOT_FUNCTION_START = 0x80000000,
UNWIND_HAS_LSDA = 0x40000000,
UNWIND_PERSONALITY_MASK = 0x30000000,
};
FLAGS_ANONYMOUS_ENUM()
{
UNWIND_X86_MODE_MASK = 0x0F000000,
UNWIND_X86_MODE_EBP_FRAME = 0x01000000,
UNWIND_X86_MODE_STACK_IMMD = 0x02000000,
UNWIND_X86_MODE_STACK_IND = 0x03000000,
UNWIND_X86_MODE_DWARF = 0x04000000,
UNWIND_X86_EBP_FRAME_REGISTERS = 0x00007FFF,
UNWIND_X86_EBP_FRAME_OFFSET = 0x00FF0000,
UNWIND_X86_FRAMELESS_STACK_SIZE = 0x00FF0000,
UNWIND_X86_FRAMELESS_STACK_ADJUST = 0x0000E000,
UNWIND_X86_FRAMELESS_STACK_REG_COUNT = 0x00001C00,
UNWIND_X86_FRAMELESS_STACK_REG_PERMUTATION = 0x000003FF,
UNWIND_X86_DWARF_SECTION_OFFSET = 0x00FFFFFF,
};
enum
{
UNWIND_X86_REG_NONE = 0,
UNWIND_X86_REG_EBX = 1,
UNWIND_X86_REG_ECX = 2,
UNWIND_X86_REG_EDX = 3,
UNWIND_X86_REG_EDI = 4,
UNWIND_X86_REG_ESI = 5,
UNWIND_X86_REG_EBP = 6,
};
FLAGS_ANONYMOUS_ENUM()
{
UNWIND_X86_64_MODE_MASK = 0x0F000000,
UNWIND_X86_64_MODE_RBP_FRAME = 0x01000000,
UNWIND_X86_64_MODE_STACK_IMMD = 0x02000000,
UNWIND_X86_64_MODE_STACK_IND = 0x03000000,
UNWIND_X86_64_MODE_DWARF = 0x04000000,
UNWIND_X86_64_RBP_FRAME_REGISTERS = 0x00007FFF,
UNWIND_X86_64_RBP_FRAME_OFFSET = 0x00FF0000,
UNWIND_X86_64_FRAMELESS_STACK_SIZE = 0x00FF0000,
UNWIND_X86_64_FRAMELESS_STACK_ADJUST = 0x0000E000,
UNWIND_X86_64_FRAMELESS_STACK_REG_COUNT = 0x00001C00,
UNWIND_X86_64_FRAMELESS_STACK_REG_PERMUTATION = 0x000003FF,
UNWIND_X86_64_DWARF_SECTION_OFFSET = 0x00FFFFFF,
};
enum
{
UNWIND_X86_64_REG_NONE = 0,
UNWIND_X86_64_REG_RBX = 1,
UNWIND_X86_64_REG_R12 = 2,
UNWIND_X86_64_REG_R13 = 3,
UNWIND_X86_64_REG_R14 = 4,
UNWIND_X86_64_REG_R15 = 5,
UNWIND_X86_64_REG_RBP = 6,
};
}
#ifndef UNWIND_SECOND_LEVEL_REGULAR
#define UNWIND_SECOND_LEVEL_REGULAR 2
#endif
#ifndef UNWIND_SECOND_LEVEL_COMPRESSED
#define UNWIND_SECOND_LEVEL_COMPRESSED 3
#endif
#ifndef UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET
#define UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET(entry) (entry & 0x00FFFFFF)
#endif
#ifndef UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX
#define UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX(entry) ((entry >> 24) & 0xFF)
#endif
#define EXTRACT_BITS(value, mask) \
( (value >> llvm::countTrailingZeros(static_cast<uint32_t>(mask), llvm::ZB_Width)) & \
(((1 << llvm::countPopulation(static_cast<uint32_t>(mask))))-1) )
//----------------------
// constructor
//----------------------
CompactUnwindInfo::CompactUnwindInfo(ObjectFile& objfile, SectionSP& section_sp) :
m_objfile (objfile),
m_section_sp (section_sp),
m_section_contents_if_encrypted (),
m_mutex (),
m_indexes (),
m_indexes_computed (eLazyBoolCalculate),
m_unwindinfo_data (),
m_unwindinfo_data_computed (false),
m_unwind_header ()
{
}
//----------------------
// destructor
//----------------------
CompactUnwindInfo::~CompactUnwindInfo()
{
}
bool
CompactUnwindInfo::GetUnwindPlan (Target &target, Address addr, UnwindPlan& unwind_plan)
{
if (!IsValid (target.GetProcessSP()))
{
return false;
}
FunctionInfo function_info;
if (GetCompactUnwindInfoForFunction (target, addr, function_info))
{
// shortcut return for functions that have no compact unwind
if (function_info.encoding == 0)
return false;
ArchSpec arch;
if (m_objfile.GetArchitecture (arch))
{
Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
if (log && log->GetVerbose())
{
StreamString strm;
addr.Dump (&strm, NULL, Address::DumpStyle::DumpStyleResolvedDescriptionNoFunctionArguments, Address::DumpStyle::DumpStyleFileAddress, arch.GetAddressByteSize());
log->Printf ("Got compact unwind encoding 0x%x for function %s", function_info.encoding, strm.GetData());
}
if (function_info.valid_range_offset_start != 0 && function_info.valid_range_offset_end != 0)
{
SectionList *sl = m_objfile.GetSectionList ();
if (sl)
{
addr_t func_range_start_file_addr =
function_info.valid_range_offset_start + m_objfile.GetHeaderAddress().GetFileAddress();
AddressRange func_range (func_range_start_file_addr,
function_info.valid_range_offset_end - function_info.valid_range_offset_start,
sl);
unwind_plan.SetPlanValidAddressRange (func_range);
}
}
if (arch.GetTriple().getArch() == llvm::Triple::x86_64)
{
return CreateUnwindPlan_x86_64 (target, function_info, unwind_plan, addr);
}
if (arch.GetTriple().getArch() == llvm::Triple::x86)
{
return CreateUnwindPlan_i386 (target, function_info, unwind_plan, addr);
}
}
}
return false;
}
bool
CompactUnwindInfo::IsValid (const ProcessSP &process_sp)
{
if (m_section_sp.get() == nullptr)
return false;
if (m_indexes_computed == eLazyBoolYes && m_unwindinfo_data_computed)
return true;
ScanIndex (process_sp);
return m_indexes_computed == eLazyBoolYes && m_unwindinfo_data_computed;
}
void
CompactUnwindInfo::ScanIndex (const ProcessSP &process_sp)
{
Mutex::Locker locker(m_mutex);
if (m_indexes_computed == eLazyBoolYes && m_unwindinfo_data_computed)
return;
// We can't read the index for some reason.
if (m_indexes_computed == eLazyBoolNo)
{
return;
}
Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
if (log)
m_objfile.GetModule()->LogMessage(log, "Reading compact unwind first-level indexes");
if (m_unwindinfo_data_computed == false)
{
if (m_section_sp->IsEncrypted())
{
// Can't get section contents of a protected/encrypted section until we have a live
// process and can read them out of memory.
if (process_sp.get() == nullptr)
return;
m_section_contents_if_encrypted.reset (new DataBufferHeap (m_section_sp->GetByteSize(), 0));
Error error;
if (process_sp->ReadMemory (
m_section_sp->GetLoadBaseAddress (&process_sp->GetTarget()),
m_section_contents_if_encrypted->GetBytes(),
m_section_sp->GetByteSize(), error) == m_section_sp->GetByteSize() && error.Success())
{
m_unwindinfo_data.SetAddressByteSize (process_sp->GetTarget().GetArchitecture().GetAddressByteSize());
m_unwindinfo_data.SetByteOrder (process_sp->GetTarget().GetArchitecture().GetByteOrder());
m_unwindinfo_data.SetData (m_section_contents_if_encrypted, 0);
}
}
else
{
m_objfile.ReadSectionData (m_section_sp.get(), m_unwindinfo_data);
}
if (m_unwindinfo_data.GetByteSize() != m_section_sp->GetByteSize())
return;
m_unwindinfo_data_computed = true;
}
if (m_unwindinfo_data.GetByteSize() > 0)
{
offset_t offset = 0;
// struct unwind_info_section_header
// {
// uint32_t version; // UNWIND_SECTION_VERSION
// uint32_t commonEncodingsArraySectionOffset;
// uint32_t commonEncodingsArrayCount;
// uint32_t personalityArraySectionOffset;
// uint32_t personalityArrayCount;
// uint32_t indexSectionOffset;
// uint32_t indexCount;
m_unwind_header.version = m_unwindinfo_data.GetU32(&offset);
m_unwind_header.common_encodings_array_offset = m_unwindinfo_data.GetU32(&offset);
m_unwind_header.common_encodings_array_count = m_unwindinfo_data.GetU32(&offset);
m_unwind_header.personality_array_offset = m_unwindinfo_data.GetU32(&offset);
m_unwind_header.personality_array_count = m_unwindinfo_data.GetU32(&offset);
uint32_t indexSectionOffset = m_unwindinfo_data.GetU32(&offset);
uint32_t indexCount = m_unwindinfo_data.GetU32(&offset);
if (m_unwind_header.common_encodings_array_offset > m_unwindinfo_data.GetByteSize()
|| m_unwind_header.personality_array_offset > m_unwindinfo_data.GetByteSize()
|| indexSectionOffset > m_unwindinfo_data.GetByteSize()
|| offset > m_unwindinfo_data.GetByteSize())
{
Host::SystemLog (Host::eSystemLogError,
"error: Invalid offset encountered in compact unwind info, skipping\n");
// don't trust anything from this compact_unwind section if it looks
// blatantly invalid data in the header.
m_indexes_computed = eLazyBoolNo;
return;
}
// Parse the basic information from the indexes
// We wait to scan the second level page info until it's needed
// struct unwind_info_section_header_index_entry
// {
// uint32_t functionOffset;
// uint32_t secondLevelPagesSectionOffset;
// uint32_t lsdaIndexArraySectionOffset;
// };
offset = indexSectionOffset;
for (uint32_t idx = 0; idx < indexCount; idx++)
{
uint32_t function_offset = m_unwindinfo_data.GetU32(&offset); // functionOffset
uint32_t second_level_offset = m_unwindinfo_data.GetU32(&offset); // secondLevelPagesSectionOffset
uint32_t lsda_offset = m_unwindinfo_data.GetU32(&offset); // lsdaIndexArraySectionOffset
if (second_level_offset > m_section_sp->GetByteSize() || lsda_offset > m_section_sp->GetByteSize())
{
m_indexes_computed = eLazyBoolNo;
}
UnwindIndex this_index;
this_index.function_offset = function_offset; //
this_index.second_level = second_level_offset;
this_index.lsda_array_start = lsda_offset;
if (m_indexes.size() > 0)
{
m_indexes[m_indexes.size() - 1].lsda_array_end = lsda_offset;
}
if (second_level_offset == 0)
{
this_index.sentinal_entry = true;
}
m_indexes.push_back (this_index);
}
m_indexes_computed = eLazyBoolYes;
}
else
{
m_indexes_computed = eLazyBoolNo;
}
}
uint32_t
CompactUnwindInfo::GetLSDAForFunctionOffset (uint32_t lsda_offset, uint32_t lsda_count, uint32_t function_offset)
{
// struct unwind_info_section_header_lsda_index_entry
// {
// uint32_t functionOffset;
// uint32_t lsdaOffset;
// };
offset_t first_entry = lsda_offset;
uint32_t low = 0;
uint32_t high = lsda_count;
while (low < high)
{
uint32_t mid = (low + high) / 2;
offset_t offset = first_entry + (mid * 8);
uint32_t mid_func_offset = m_unwindinfo_data.GetU32(&offset); // functionOffset
uint32_t mid_lsda_offset = m_unwindinfo_data.GetU32(&offset); // lsdaOffset
if (mid_func_offset == function_offset)
{
return mid_lsda_offset;
}
if (mid_func_offset < function_offset)
{
low = mid + 1;
}
else
{
high = mid;
}
}
return 0;
}
lldb::offset_t
CompactUnwindInfo::BinarySearchRegularSecondPage (uint32_t entry_page_offset, uint32_t entry_count, uint32_t function_offset, uint32_t *entry_func_start_offset, uint32_t *entry_func_end_offset)
{
// typedef uint32_t compact_unwind_encoding_t;
// struct unwind_info_regular_second_level_entry
// {
// uint32_t functionOffset;
// compact_unwind_encoding_t encoding;
offset_t first_entry = entry_page_offset;
uint32_t low = 0;
uint32_t high = entry_count;
uint32_t last = high - 1;
while (low < high)
{
uint32_t mid = (low + high) / 2;
offset_t offset = first_entry + (mid * 8);
uint32_t mid_func_offset = m_unwindinfo_data.GetU32(&offset); // functionOffset
uint32_t next_func_offset = 0;
if (mid < last)
{
offset = first_entry + ((mid + 1) * 8);
next_func_offset = m_unwindinfo_data.GetU32(&offset); // functionOffset
}
if (mid_func_offset <= function_offset)
{
if (mid == last || (next_func_offset > function_offset))
{
if (entry_func_start_offset)
*entry_func_start_offset = mid_func_offset;
if (mid != last && entry_func_end_offset)
*entry_func_end_offset = next_func_offset;
return first_entry + (mid * 8);
}
else
{
low = mid + 1;
}
}
else
{
high = mid;
}
}
return LLDB_INVALID_OFFSET;
}
uint32_t
CompactUnwindInfo::BinarySearchCompressedSecondPage (uint32_t entry_page_offset, uint32_t entry_count, uint32_t function_offset_to_find, uint32_t function_offset_base, uint32_t *entry_func_start_offset, uint32_t *entry_func_end_offset)
{
offset_t first_entry = entry_page_offset;
uint32_t low = 0;
uint32_t high = entry_count;
uint32_t last = high - 1;
while (low < high)
{
uint32_t mid = (low + high) / 2;
offset_t offset = first_entry + (mid * 4);
uint32_t entry = m_unwindinfo_data.GetU32(&offset); // entry
uint32_t mid_func_offset = UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET (entry);
mid_func_offset += function_offset_base;
uint32_t next_func_offset = 0;
if (mid < last)
{
offset = first_entry + ((mid + 1) * 4);
uint32_t next_entry = m_unwindinfo_data.GetU32(&offset); // entry
next_func_offset = UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET (next_entry);
next_func_offset += function_offset_base;
}
if (mid_func_offset <= function_offset_to_find)
{
if (mid == last || (next_func_offset > function_offset_to_find))
{
if (entry_func_start_offset)
*entry_func_start_offset = mid_func_offset;
if (mid != last && entry_func_end_offset)
*entry_func_end_offset = next_func_offset;
return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX (entry);
}
else
{
low = mid + 1;
}
}
else
{
high = mid;
}
}
return UINT32_MAX;
}
bool
CompactUnwindInfo::GetCompactUnwindInfoForFunction (Target &target, Address address, FunctionInfo &unwind_info)
{
unwind_info.encoding = 0;
unwind_info.lsda_address.Clear();
unwind_info.personality_ptr_address.Clear();
if (!IsValid (target.GetProcessSP()))
return false;
addr_t text_section_file_address = LLDB_INVALID_ADDRESS;
SectionList *sl = m_objfile.GetSectionList ();
if (sl)
{
SectionSP text_sect = sl->FindSectionByType (eSectionTypeCode, true);
if (text_sect.get())
{
text_section_file_address = text_sect->GetFileAddress();
}
}
if (text_section_file_address == LLDB_INVALID_ADDRESS)
return false;
addr_t function_offset = address.GetFileAddress() - m_objfile.GetHeaderAddress().GetFileAddress();
UnwindIndex key;
key.function_offset = function_offset;
std::vector<UnwindIndex>::const_iterator it;
it = std::lower_bound (m_indexes.begin(), m_indexes.end(), key);
if (it == m_indexes.end())
{
return false;
}
if (it->function_offset != key.function_offset)
{
if (it != m_indexes.begin())
--it;
}
if (it->sentinal_entry == true)
{
return false;
}
auto next_it = it + 1;
if (next_it != m_indexes.end())
{
// initialize the function offset end range to be the start of the
// next index offset. If we find an entry which is at the end of
// the index table, this will establish the range end.
unwind_info.valid_range_offset_end = next_it->function_offset;
}
offset_t second_page_offset = it->second_level;
offset_t lsda_array_start = it->lsda_array_start;
offset_t lsda_array_count = (it->lsda_array_end - it->lsda_array_start) / 8;
offset_t offset = second_page_offset;
uint32_t kind = m_unwindinfo_data.GetU32(&offset); // UNWIND_SECOND_LEVEL_REGULAR or UNWIND_SECOND_LEVEL_COMPRESSED
if (kind == UNWIND_SECOND_LEVEL_REGULAR)
{
// struct unwind_info_regular_second_level_page_header
// {
// uint32_t kind; // UNWIND_SECOND_LEVEL_REGULAR
// uint16_t entryPageOffset;
// uint16_t entryCount;
// typedef uint32_t compact_unwind_encoding_t;
// struct unwind_info_regular_second_level_entry
// {
// uint32_t functionOffset;
// compact_unwind_encoding_t encoding;
uint16_t entry_page_offset = m_unwindinfo_data.GetU16(&offset); // entryPageOffset
uint16_t entry_count = m_unwindinfo_data.GetU16(&offset); // entryCount
offset_t entry_offset = BinarySearchRegularSecondPage (second_page_offset + entry_page_offset, entry_count, function_offset, &unwind_info.valid_range_offset_start, &unwind_info.valid_range_offset_end);
if (entry_offset == LLDB_INVALID_OFFSET)
{
return false;
}
entry_offset += 4; // skip over functionOffset
unwind_info.encoding = m_unwindinfo_data.GetU32(&entry_offset); // encoding
if (unwind_info.encoding & UNWIND_HAS_LSDA)
{
SectionList *sl = m_objfile.GetSectionList ();
if (sl)
{
uint32_t lsda_offset = GetLSDAForFunctionOffset (lsda_array_start, lsda_array_count, function_offset);
addr_t objfile_header_file_address = m_objfile.GetHeaderAddress().GetFileAddress();
unwind_info.lsda_address.ResolveAddressUsingFileSections (objfile_header_file_address + lsda_offset, sl);
}
}
if (unwind_info.encoding & UNWIND_PERSONALITY_MASK)
{
uint32_t personality_index = EXTRACT_BITS (unwind_info.encoding, UNWIND_PERSONALITY_MASK);
if (personality_index > 0)
{
personality_index--;
if (personality_index < m_unwind_header.personality_array_count)
{
offset_t offset = m_unwind_header.personality_array_offset;
offset += 4 * personality_index;
SectionList *sl = m_objfile.GetSectionList ();
if (sl)
{
uint32_t personality_offset = m_unwindinfo_data.GetU32(&offset);
addr_t objfile_header_file_address = m_objfile.GetHeaderAddress().GetFileAddress();
unwind_info.personality_ptr_address.ResolveAddressUsingFileSections (objfile_header_file_address + personality_offset, sl);
}
}
}
}
return true;
}
else if (kind == UNWIND_SECOND_LEVEL_COMPRESSED)
{
// struct unwind_info_compressed_second_level_page_header
// {
// uint32_t kind; // UNWIND_SECOND_LEVEL_COMPRESSED
// uint16_t entryPageOffset; // offset from this 2nd lvl page idx to array of entries
// // (an entry has a function offset and index into the encodings)
// // NB function offset from the entry in the compressed page
// // must be added to the index's functionOffset value.
// uint16_t entryCount;
// uint16_t encodingsPageOffset; // offset from this 2nd lvl page idx to array of encodings
// uint16_t encodingsCount;
uint16_t entry_page_offset = m_unwindinfo_data.GetU16(&offset); // entryPageOffset
uint16_t entry_count = m_unwindinfo_data.GetU16(&offset); // entryCount
uint16_t encodings_page_offset = m_unwindinfo_data.GetU16(&offset); // encodingsPageOffset
uint16_t encodings_count = m_unwindinfo_data.GetU16(&offset); // encodingsCount
uint32_t encoding_index = BinarySearchCompressedSecondPage (second_page_offset + entry_page_offset, entry_count, function_offset, it->function_offset, &unwind_info.valid_range_offset_start, &unwind_info.valid_range_offset_end);
if (encoding_index == UINT32_MAX || encoding_index >= encodings_count + m_unwind_header.common_encodings_array_count)
{
return false;
}
uint32_t encoding = 0;
if (encoding_index < m_unwind_header.common_encodings_array_count)
{
offset = m_unwind_header.common_encodings_array_offset + (encoding_index * sizeof (uint32_t));
encoding = m_unwindinfo_data.GetU32(&offset); // encoding entry from the commonEncodingsArray
}
else
{
uint32_t page_specific_entry_index = encoding_index - m_unwind_header.common_encodings_array_count;
offset = second_page_offset + encodings_page_offset + (page_specific_entry_index * sizeof (uint32_t));
encoding = m_unwindinfo_data.GetU32(&offset); // encoding entry from the page-specific encoding array
}
if (encoding == 0)
return false;
unwind_info.encoding = encoding;
if (unwind_info.encoding & UNWIND_HAS_LSDA)
{
SectionList *sl = m_objfile.GetSectionList ();
if (sl)
{
uint32_t lsda_offset = GetLSDAForFunctionOffset (lsda_array_start, lsda_array_count, function_offset);
addr_t objfile_header_file_address = m_objfile.GetHeaderAddress().GetFileAddress();
unwind_info.lsda_address.ResolveAddressUsingFileSections (objfile_header_file_address + lsda_offset, sl);
}
}
if (unwind_info.encoding & UNWIND_PERSONALITY_MASK)
{
uint32_t personality_index = EXTRACT_BITS (unwind_info.encoding, UNWIND_PERSONALITY_MASK);
if (personality_index > 0)
{
personality_index--;
if (personality_index < m_unwind_header.personality_array_count)
{
offset_t offset = m_unwind_header.personality_array_offset;
offset += 4 * personality_index;
SectionList *sl = m_objfile.GetSectionList ();
if (sl)
{
uint32_t personality_offset = m_unwindinfo_data.GetU32(&offset);
addr_t objfile_header_file_address = m_objfile.GetHeaderAddress().GetFileAddress();
unwind_info.personality_ptr_address.ResolveAddressUsingFileSections (objfile_header_file_address + personality_offset, sl);
}
}
}
}
return true;
}
return false;
}
enum x86_64_eh_regnum {
rax = 0,
rdx = 1,
rcx = 2,
rbx = 3,
rsi = 4,
rdi = 5,
rbp = 6,
rsp = 7,
r8 = 8,
r9 = 9,
r10 = 10,
r11 = 11,
r12 = 12,
r13 = 13,
r14 = 14,
r15 = 15,
rip = 16 // this is officially the Return Address register number, but close enough
};
// Convert the compact_unwind_info.h register numbering scheme
// to eRegisterKindEHFrame (eh_frame) register numbering scheme.
uint32_t
translate_to_eh_frame_regnum_x86_64 (uint32_t unwind_regno)
{
switch (unwind_regno)
{
case UNWIND_X86_64_REG_RBX:
return x86_64_eh_regnum::rbx;
case UNWIND_X86_64_REG_R12:
return x86_64_eh_regnum::r12;
case UNWIND_X86_64_REG_R13:
return x86_64_eh_regnum::r13;
case UNWIND_X86_64_REG_R14:
return x86_64_eh_regnum::r14;
case UNWIND_X86_64_REG_R15:
return x86_64_eh_regnum::r15;
case UNWIND_X86_64_REG_RBP:
return x86_64_eh_regnum::rbp;
default:
return LLDB_INVALID_REGNUM;
}
}
bool
CompactUnwindInfo::CreateUnwindPlan_x86_64 (Target &target, FunctionInfo &function_info, UnwindPlan &unwind_plan, Address pc_or_function_start)
{
unwind_plan.SetSourceName ("compact unwind info");
unwind_plan.SetSourcedFromCompiler (eLazyBoolYes);
unwind_plan.SetUnwindPlanValidAtAllInstructions (eLazyBoolNo);
unwind_plan.SetRegisterKind (eRegisterKindEHFrame);
unwind_plan.SetLSDAAddress (function_info.lsda_address);
unwind_plan.SetPersonalityFunctionPtr (function_info.personality_ptr_address);
UnwindPlan::RowSP row (new UnwindPlan::Row);
const int wordsize = 8;
int mode = function_info.encoding & UNWIND_X86_64_MODE_MASK;
switch (mode)
{
case UNWIND_X86_64_MODE_RBP_FRAME:
{
row->GetCFAValue().SetIsRegisterPlusOffset (
translate_to_eh_frame_regnum_x86_64 (UNWIND_X86_64_REG_RBP),
2 * wordsize);
row->SetOffset (0);
row->SetRegisterLocationToAtCFAPlusOffset (x86_64_eh_regnum::rbp, wordsize * -2, true);
row->SetRegisterLocationToAtCFAPlusOffset (x86_64_eh_regnum::rip, wordsize * -1, true);
row->SetRegisterLocationToIsCFAPlusOffset (x86_64_eh_regnum::rsp, 0, true);
uint32_t saved_registers_offset = EXTRACT_BITS (function_info.encoding, UNWIND_X86_64_RBP_FRAME_OFFSET);
uint32_t saved_registers_locations = EXTRACT_BITS (function_info.encoding, UNWIND_X86_64_RBP_FRAME_REGISTERS);
saved_registers_offset += 2;
for (int i = 0; i < 5; i++)
{
uint32_t regnum = saved_registers_locations & 0x7;
switch (regnum)
{
case UNWIND_X86_64_REG_NONE:
break;
case UNWIND_X86_64_REG_RBX:
case UNWIND_X86_64_REG_R12:
case UNWIND_X86_64_REG_R13:
case UNWIND_X86_64_REG_R14:
case UNWIND_X86_64_REG_R15:
row->SetRegisterLocationToAtCFAPlusOffset (translate_to_eh_frame_regnum_x86_64 (regnum), wordsize * -saved_registers_offset, true);
break;
}
saved_registers_offset--;
saved_registers_locations >>= 3;
}
unwind_plan.AppendRow (row);
return true;
}
break;
case UNWIND_X86_64_MODE_STACK_IND:
{
// The clang in Xcode 6 is emitting incorrect compact unwind encodings for this
// style of unwind. It was fixed in llvm r217020.
// The clang in Xcode 7 has this fixed.
return false;
}
break;
case UNWIND_X86_64_MODE_STACK_IMMD:
{
uint32_t stack_size = EXTRACT_BITS (function_info.encoding, UNWIND_X86_64_FRAMELESS_STACK_SIZE);
uint32_t register_count = EXTRACT_BITS (function_info.encoding, UNWIND_X86_64_FRAMELESS_STACK_REG_COUNT);
uint32_t permutation = EXTRACT_BITS (function_info.encoding, UNWIND_X86_64_FRAMELESS_STACK_REG_PERMUTATION);
if (mode == UNWIND_X86_64_MODE_STACK_IND && function_info.valid_range_offset_start != 0)
{
uint32_t stack_adjust = EXTRACT_BITS (function_info.encoding, UNWIND_X86_64_FRAMELESS_STACK_ADJUST);
// offset into the function instructions; 0 == beginning of first instruction
uint32_t offset_to_subl_insn = EXTRACT_BITS (function_info.encoding, UNWIND_X86_64_FRAMELESS_STACK_SIZE);
SectionList *sl = m_objfile.GetSectionList ();
if (sl)
{
ProcessSP process_sp = target.GetProcessSP();
if (process_sp)
{
Address subl_payload_addr (function_info.valid_range_offset_start, sl);
subl_payload_addr.Slide (offset_to_subl_insn);
Error error;
uint64_t large_stack_size = process_sp->ReadUnsignedIntegerFromMemory (subl_payload_addr.GetLoadAddress (&target),
4, 0, error);
if (large_stack_size != 0 && error.Success ())
{
// Got the large stack frame size correctly - use it
stack_size = large_stack_size + (stack_adjust * wordsize);
}
else
{
return false;
}
}
else
{
return false;
}
}
else
{
return false;
}
}
int32_t offset = mode == UNWIND_X86_64_MODE_STACK_IND ? stack_size : stack_size * wordsize;
row->GetCFAValue().SetIsRegisterPlusOffset (x86_64_eh_regnum::rsp, offset);
row->SetOffset (0);
row->SetRegisterLocationToAtCFAPlusOffset (x86_64_eh_regnum::rip, wordsize * -1, true);
row->SetRegisterLocationToIsCFAPlusOffset (x86_64_eh_regnum::rsp, 0, true);
if (register_count > 0)
{
// We need to include (up to) 6 registers in 10 bits.
// That would be 18 bits if we just used 3 bits per reg to indicate
// the order they're saved on the stack.
//
// This is done with Lehmer code permutation, e.g. see
// http://stackoverflow.com/questions/1506078/fast-permutation-number-permutation-mapping-algorithms
int permunreg[6] = {0, 0, 0, 0, 0, 0};
// This decodes the variable-base number in the 10 bits
// and gives us the Lehmer code sequence which can then
// be decoded.
switch (register_count)
{
case 6:
permunreg[0] = permutation/120; // 120 == 5!
permutation -= (permunreg[0]*120);
permunreg[1] = permutation/24; // 24 == 4!
permutation -= (permunreg[1]*24);
permunreg[2] = permutation/6; // 6 == 3!
permutation -= (permunreg[2]*6);
permunreg[3] = permutation/2; // 2 == 2!
permutation -= (permunreg[3]*2);
permunreg[4] = permutation; // 1 == 1!
permunreg[5] = 0;
break;
case 5:
permunreg[0] = permutation/120;
permutation -= (permunreg[0]*120);
permunreg[1] = permutation/24;
permutation -= (permunreg[1]*24);
permunreg[2] = permutation/6;
permutation -= (permunreg[2]*6);
permunreg[3] = permutation/2;
permutation -= (permunreg[3]*2);
permunreg[4] = permutation;
break;
case 4:
permunreg[0] = permutation/60;
permutation -= (permunreg[0]*60);
permunreg[1] = permutation/12;
permutation -= (permunreg[1]*12);
permunreg[2] = permutation/3;
permutation -= (permunreg[2]*3);
permunreg[3] = permutation;
break;
case 3:
permunreg[0] = permutation/20;
permutation -= (permunreg[0]*20);
permunreg[1] = permutation/4;
permutation -= (permunreg[1]*4);
permunreg[2] = permutation;
break;
case 2:
permunreg[0] = permutation/5;
permutation -= (permunreg[0]*5);
permunreg[1] = permutation;
break;
case 1:
permunreg[0] = permutation;
break;
}
// Decode the Lehmer code for this permutation of
// the registers v. http://en.wikipedia.org/wiki/Lehmer_code
int registers[6] = { UNWIND_X86_64_REG_NONE, UNWIND_X86_64_REG_NONE, UNWIND_X86_64_REG_NONE, UNWIND_X86_64_REG_NONE, UNWIND_X86_64_REG_NONE, UNWIND_X86_64_REG_NONE };
bool used[7] = { false, false, false, false, false, false, false };
for (uint32_t i = 0; i < register_count; i++)
{
int renum = 0;
for (int j = 1; j < 7; j++)
{
if (used[j] == false)
{
if (renum == permunreg[i])
{
registers[i] = j;
used[j] = true;
break;
}
renum++;
}
}
}
uint32_t saved_registers_offset = 1;
saved_registers_offset++;
for (int i = (sizeof (registers) / sizeof (int)) - 1; i >= 0; i--)
{
switch (registers[i])
{
case UNWIND_X86_64_REG_NONE:
break;
case UNWIND_X86_64_REG_RBX:
case UNWIND_X86_64_REG_R12:
case UNWIND_X86_64_REG_R13:
case UNWIND_X86_64_REG_R14:
case UNWIND_X86_64_REG_R15:
case UNWIND_X86_64_REG_RBP:
row->SetRegisterLocationToAtCFAPlusOffset (translate_to_eh_frame_regnum_x86_64 (registers[i]), wordsize * -saved_registers_offset, true);
saved_registers_offset++;
break;
}
}
}
unwind_plan.AppendRow (row);
return true;
}
break;
case UNWIND_X86_64_MODE_DWARF:
{
return false;
}
break;
case 0:
{
return false;
}
break;
}
return false;
}
enum i386_eh_regnum {
eax = 0,
ecx = 1,
edx = 2,
ebx = 3,
ebp = 4,
esp = 5,
esi = 6,
edi = 7,
eip = 8 // this is officially the Return Address register number, but close enough
};
// Convert the compact_unwind_info.h register numbering scheme
// to eRegisterKindEHFrame (eh_frame) register numbering scheme.
uint32_t
translate_to_eh_frame_regnum_i386 (uint32_t unwind_regno)
{
switch (unwind_regno)
{
case UNWIND_X86_REG_EBX:
return i386_eh_regnum::ebx;
case UNWIND_X86_REG_ECX:
return i386_eh_regnum::ecx;
case UNWIND_X86_REG_EDX:
return i386_eh_regnum::edx;
case UNWIND_X86_REG_EDI:
return i386_eh_regnum::edi;
case UNWIND_X86_REG_ESI:
return i386_eh_regnum::esi;
case UNWIND_X86_REG_EBP:
return i386_eh_regnum::ebp;
default:
return LLDB_INVALID_REGNUM;
}
}
bool
CompactUnwindInfo::CreateUnwindPlan_i386 (Target &target, FunctionInfo &function_info, UnwindPlan &unwind_plan, Address pc_or_function_start)
{
unwind_plan.SetSourceName ("compact unwind info");
unwind_plan.SetSourcedFromCompiler (eLazyBoolYes);
unwind_plan.SetUnwindPlanValidAtAllInstructions (eLazyBoolNo);
unwind_plan.SetRegisterKind (eRegisterKindEHFrame);
unwind_plan.SetLSDAAddress (function_info.lsda_address);
unwind_plan.SetPersonalityFunctionPtr (function_info.personality_ptr_address);
UnwindPlan::RowSP row (new UnwindPlan::Row);
const int wordsize = 4;
int mode = function_info.encoding & UNWIND_X86_MODE_MASK;
switch (mode)
{
case UNWIND_X86_MODE_EBP_FRAME:
{
row->GetCFAValue().SetIsRegisterPlusOffset (
translate_to_eh_frame_regnum_i386 (UNWIND_X86_REG_EBP), 2 * wordsize);
row->SetOffset (0);
row->SetRegisterLocationToAtCFAPlusOffset (i386_eh_regnum::ebp, wordsize * -2, true);
row->SetRegisterLocationToAtCFAPlusOffset (i386_eh_regnum::eip, wordsize * -1, true);
row->SetRegisterLocationToIsCFAPlusOffset (i386_eh_regnum::esp, 0, true);
uint32_t saved_registers_offset = EXTRACT_BITS (function_info.encoding, UNWIND_X86_EBP_FRAME_OFFSET);
uint32_t saved_registers_locations = EXTRACT_BITS (function_info.encoding, UNWIND_X86_EBP_FRAME_REGISTERS);
saved_registers_offset += 2;
for (int i = 0; i < 5; i++)
{
uint32_t regnum = saved_registers_locations & 0x7;
switch (regnum)
{
case UNWIND_X86_REG_NONE:
break;
case UNWIND_X86_REG_EBX:
case UNWIND_X86_REG_ECX:
case UNWIND_X86_REG_EDX:
case UNWIND_X86_REG_EDI:
case UNWIND_X86_REG_ESI:
row->SetRegisterLocationToAtCFAPlusOffset (translate_to_eh_frame_regnum_i386 (regnum), wordsize * -saved_registers_offset, true);
break;
}
saved_registers_offset--;
saved_registers_locations >>= 3;
}
unwind_plan.AppendRow (row);
return true;
}
break;
case UNWIND_X86_MODE_STACK_IND:
case UNWIND_X86_MODE_STACK_IMMD:
{
uint32_t stack_size = EXTRACT_BITS (function_info.encoding, UNWIND_X86_FRAMELESS_STACK_SIZE);
uint32_t register_count = EXTRACT_BITS (function_info.encoding, UNWIND_X86_FRAMELESS_STACK_REG_COUNT);
uint32_t permutation = EXTRACT_BITS (function_info.encoding, UNWIND_X86_FRAMELESS_STACK_REG_PERMUTATION);
if (mode == UNWIND_X86_MODE_STACK_IND && function_info.valid_range_offset_start != 0)
{
uint32_t stack_adjust = EXTRACT_BITS (function_info.encoding, UNWIND_X86_FRAMELESS_STACK_ADJUST);
// offset into the function instructions; 0 == beginning of first instruction
uint32_t offset_to_subl_insn = EXTRACT_BITS (function_info.encoding, UNWIND_X86_FRAMELESS_STACK_SIZE);
SectionList *sl = m_objfile.GetSectionList ();
if (sl)
{
ProcessSP process_sp = target.GetProcessSP();
if (process_sp)
{
Address subl_payload_addr (function_info.valid_range_offset_start, sl);
subl_payload_addr.Slide (offset_to_subl_insn);
Error error;
uint64_t large_stack_size = process_sp->ReadUnsignedIntegerFromMemory (subl_payload_addr.GetLoadAddress (&target),
4, 0, error);
if (large_stack_size != 0 && error.Success ())
{
// Got the large stack frame size correctly - use it
stack_size = large_stack_size + (stack_adjust * wordsize);
}
else
{
return false;
}
}
else
{
return false;
}
}
else
{
return false;
}
}
int32_t offset = mode == UNWIND_X86_MODE_STACK_IND ? stack_size : stack_size * wordsize;
row->GetCFAValue().SetIsRegisterPlusOffset (i386_eh_regnum::esp, offset);
row->SetOffset (0);
row->SetRegisterLocationToAtCFAPlusOffset (i386_eh_regnum::eip, wordsize * -1, true);
row->SetRegisterLocationToIsCFAPlusOffset (i386_eh_regnum::esp, 0, true);
if (register_count > 0)
{
// We need to include (up to) 6 registers in 10 bits.
// That would be 18 bits if we just used 3 bits per reg to indicate
// the order they're saved on the stack.
//
// This is done with Lehmer code permutation, e.g. see
// http://stackoverflow.com/questions/1506078/fast-permutation-number-permutation-mapping-algorithms
int permunreg[6] = {0, 0, 0, 0, 0, 0};
// This decodes the variable-base number in the 10 bits
// and gives us the Lehmer code sequence which can then
// be decoded.
switch (register_count)
{
case 6:
permunreg[0] = permutation/120; // 120 == 5!
permutation -= (permunreg[0]*120);
permunreg[1] = permutation/24; // 24 == 4!
permutation -= (permunreg[1]*24);
permunreg[2] = permutation/6; // 6 == 3!
permutation -= (permunreg[2]*6);
permunreg[3] = permutation/2; // 2 == 2!
permutation -= (permunreg[3]*2);
permunreg[4] = permutation; // 1 == 1!
permunreg[5] = 0;
break;
case 5:
permunreg[0] = permutation/120;
permutation -= (permunreg[0]*120);
permunreg[1] = permutation/24;
permutation -= (permunreg[1]*24);
permunreg[2] = permutation/6;
permutation -= (permunreg[2]*6);
permunreg[3] = permutation/2;
permutation -= (permunreg[3]*2);
permunreg[4] = permutation;
break;
case 4:
permunreg[0] = permutation/60;
permutation -= (permunreg[0]*60);
permunreg[1] = permutation/12;
permutation -= (permunreg[1]*12);
permunreg[2] = permutation/3;
permutation -= (permunreg[2]*3);
permunreg[3] = permutation;
break;
case 3:
permunreg[0] = permutation/20;
permutation -= (permunreg[0]*20);
permunreg[1] = permutation/4;
permutation -= (permunreg[1]*4);
permunreg[2] = permutation;
break;
case 2:
permunreg[0] = permutation/5;
permutation -= (permunreg[0]*5);
permunreg[1] = permutation;
break;
case 1:
permunreg[0] = permutation;
break;
}
// Decode the Lehmer code for this permutation of
// the registers v. http://en.wikipedia.org/wiki/Lehmer_code
int registers[6] = { UNWIND_X86_REG_NONE, UNWIND_X86_REG_NONE, UNWIND_X86_REG_NONE, UNWIND_X86_REG_NONE, UNWIND_X86_REG_NONE, UNWIND_X86_REG_NONE };
bool used[7] = { false, false, false, false, false, false, false };
for (uint32_t i = 0; i < register_count; i++)
{
int renum = 0;
for (int j = 1; j < 7; j++)
{
if (used[j] == false)
{
if (renum == permunreg[i])
{
registers[i] = j;
used[j] = true;
break;
}
renum++;
}
}
}
uint32_t saved_registers_offset = 1;
saved_registers_offset++;
for (int i = (sizeof (registers) / sizeof (int)) - 1; i >= 0; i--)
{
switch (registers[i])
{
case UNWIND_X86_REG_NONE:
break;
case UNWIND_X86_REG_EBX:
case UNWIND_X86_REG_ECX:
case UNWIND_X86_REG_EDX:
case UNWIND_X86_REG_EDI:
case UNWIND_X86_REG_ESI:
case UNWIND_X86_REG_EBP:
row->SetRegisterLocationToAtCFAPlusOffset (translate_to_eh_frame_regnum_i386 (registers[i]), wordsize * -saved_registers_offset, true);
saved_registers_offset++;
break;
}
}
}
unwind_plan.AppendRow (row);
return true;
}
break;
case UNWIND_X86_MODE_DWARF:
{
return false;
}
break;
}
return false;
}
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