| //===-- UnwindAssembly-x86.cpp ----------------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "UnwindAssembly-x86.h" |
| |
| #include "llvm-c/Disassembler.h" |
| #include "llvm/Support/TargetSelect.h" |
| |
| #include "lldb/Core/Address.h" |
| #include "lldb/Core/Error.h" |
| #include "lldb/Core/ArchSpec.h" |
| #include "lldb/Core/PluginManager.h" |
| #include "lldb/Symbol/UnwindPlan.h" |
| #include "lldb/Target/ExecutionContext.h" |
| #include "lldb/Target/Process.h" |
| #include "lldb/Target/RegisterContext.h" |
| #include "lldb/Target/Thread.h" |
| #include "lldb/Target/Target.h" |
| #include "lldb/Target/UnwindAssembly.h" |
| |
| using namespace lldb; |
| using namespace lldb_private; |
| |
| enum CPU { |
| k_i386, |
| k_x86_64 |
| }; |
| |
| enum i386_register_numbers { |
| k_machine_eax = 0, |
| k_machine_ecx = 1, |
| k_machine_edx = 2, |
| k_machine_ebx = 3, |
| k_machine_esp = 4, |
| k_machine_ebp = 5, |
| k_machine_esi = 6, |
| k_machine_edi = 7, |
| k_machine_eip = 8 |
| }; |
| |
| enum x86_64_register_numbers { |
| k_machine_rax = 0, |
| k_machine_rcx = 1, |
| k_machine_rdx = 2, |
| k_machine_rbx = 3, |
| k_machine_rsp = 4, |
| k_machine_rbp = 5, |
| k_machine_rsi = 6, |
| k_machine_rdi = 7, |
| k_machine_r8 = 8, |
| k_machine_r9 = 9, |
| k_machine_r10 = 10, |
| k_machine_r11 = 11, |
| k_machine_r12 = 12, |
| k_machine_r13 = 13, |
| k_machine_r14 = 14, |
| k_machine_r15 = 15, |
| k_machine_rip = 16 |
| }; |
| |
| struct regmap_ent { |
| const char *name; |
| int machine_regno; |
| int lldb_regno; |
| }; |
| |
| static struct regmap_ent i386_register_map[] = { |
| {"eax", k_machine_eax, -1}, |
| {"ecx", k_machine_ecx, -1}, |
| {"edx", k_machine_edx, -1}, |
| {"ebx", k_machine_ebx, -1}, |
| {"esp", k_machine_esp, -1}, |
| {"ebp", k_machine_ebp, -1}, |
| {"esi", k_machine_esi, -1}, |
| {"edi", k_machine_edi, -1}, |
| {"eip", k_machine_eip, -1} |
| }; |
| |
| const int size_of_i386_register_map = sizeof (i386_register_map) / sizeof (struct regmap_ent); |
| |
| static int i386_register_map_initialized = 0; |
| |
| static struct regmap_ent x86_64_register_map[] = { |
| {"rax", k_machine_rax, -1}, |
| {"rcx", k_machine_rcx, -1}, |
| {"rdx", k_machine_rdx, -1}, |
| {"rbx", k_machine_rbx, -1}, |
| {"rsp", k_machine_rsp, -1}, |
| {"rbp", k_machine_rbp, -1}, |
| {"rsi", k_machine_rsi, -1}, |
| {"rdi", k_machine_rdi, -1}, |
| {"r8", k_machine_r8, -1}, |
| {"r9", k_machine_r9, -1}, |
| {"r10", k_machine_r10, -1}, |
| {"r11", k_machine_r11, -1}, |
| {"r12", k_machine_r12, -1}, |
| {"r13", k_machine_r13, -1}, |
| {"r14", k_machine_r14, -1}, |
| {"r15", k_machine_r15, -1}, |
| {"rip", k_machine_rip, -1} |
| }; |
| |
| const int size_of_x86_64_register_map = sizeof (x86_64_register_map) / sizeof (struct regmap_ent); |
| |
| static int x86_64_register_map_initialized = 0; |
| |
| //----------------------------------------------------------------------------------------------- |
| // AssemblyParse_x86 local-file class definition & implementation functions |
| //----------------------------------------------------------------------------------------------- |
| |
| class AssemblyParse_x86 { |
| public: |
| |
| AssemblyParse_x86 (const ExecutionContext &exe_ctx, int cpu, ArchSpec &arch, AddressRange func); |
| |
| ~AssemblyParse_x86 (); |
| |
| bool get_non_call_site_unwind_plan (UnwindPlan &unwind_plan); |
| |
| bool get_fast_unwind_plan (AddressRange& func, UnwindPlan &unwind_plan); |
| |
| bool find_first_non_prologue_insn (Address &address); |
| |
| private: |
| enum { kMaxInstructionByteSize = 32 }; |
| |
| bool nonvolatile_reg_p (int machine_regno); |
| bool push_rbp_pattern_p (); |
| bool push_0_pattern_p (); |
| bool mov_rsp_rbp_pattern_p (); |
| bool sub_rsp_pattern_p (int& amount); |
| bool push_reg_p (int& regno); |
| bool mov_reg_to_local_stack_frame_p (int& regno, int& fp_offset); |
| bool ret_pattern_p (); |
| uint32_t extract_4 (uint8_t *b); |
| bool machine_regno_to_lldb_regno (int machine_regno, uint32_t& lldb_regno); |
| bool instruction_length (Address addr, int &length); |
| |
| const ExecutionContext m_exe_ctx; |
| |
| AddressRange m_func_bounds; |
| |
| Address m_cur_insn; |
| uint8_t m_cur_insn_bytes[kMaxInstructionByteSize]; |
| |
| int m_machine_ip_regnum; |
| int m_machine_sp_regnum; |
| int m_machine_fp_regnum; |
| |
| int m_lldb_ip_regnum; |
| int m_lldb_sp_regnum; |
| int m_lldb_fp_regnum; |
| |
| int m_wordsize; |
| int m_cpu; |
| ArchSpec m_arch; |
| ::LLVMDisasmContextRef m_disasm_context; |
| |
| DISALLOW_COPY_AND_ASSIGN (AssemblyParse_x86); |
| }; |
| |
| AssemblyParse_x86::AssemblyParse_x86 (const ExecutionContext &exe_ctx, int cpu, ArchSpec &arch, AddressRange func) : |
| m_exe_ctx (exe_ctx), |
| m_func_bounds(func), |
| m_cur_insn (), |
| m_machine_ip_regnum (LLDB_INVALID_REGNUM), |
| m_machine_sp_regnum (LLDB_INVALID_REGNUM), |
| m_machine_fp_regnum (LLDB_INVALID_REGNUM), |
| m_lldb_ip_regnum (LLDB_INVALID_REGNUM), |
| m_lldb_sp_regnum (LLDB_INVALID_REGNUM), |
| m_lldb_fp_regnum (LLDB_INVALID_REGNUM), |
| m_wordsize (-1), |
| m_cpu(cpu), |
| m_arch(arch) |
| { |
| int *initialized_flag = NULL; |
| if (cpu == k_i386) |
| { |
| m_machine_ip_regnum = k_machine_eip; |
| m_machine_sp_regnum = k_machine_esp; |
| m_machine_fp_regnum = k_machine_ebp; |
| m_wordsize = 4; |
| initialized_flag = &i386_register_map_initialized; |
| } |
| else |
| { |
| m_machine_ip_regnum = k_machine_rip; |
| m_machine_sp_regnum = k_machine_rsp; |
| m_machine_fp_regnum = k_machine_rbp; |
| m_wordsize = 8; |
| initialized_flag = &x86_64_register_map_initialized; |
| } |
| |
| // we only look at prologue - it will be complete earlier than 512 bytes into func |
| if (m_func_bounds.GetByteSize() == 0) |
| m_func_bounds.SetByteSize(512); |
| |
| Thread *thread = m_exe_ctx.GetThreadPtr(); |
| if (thread && *initialized_flag == 0) |
| { |
| RegisterContext *reg_ctx = thread->GetRegisterContext().get(); |
| if (reg_ctx) |
| { |
| struct regmap_ent *ent; |
| int count, i; |
| if (cpu == k_i386) |
| { |
| ent = i386_register_map; |
| count = size_of_i386_register_map; |
| } |
| else |
| { |
| ent = x86_64_register_map; |
| count = size_of_x86_64_register_map; |
| } |
| for (i = 0; i < count; i++, ent++) |
| { |
| const RegisterInfo *ri = reg_ctx->GetRegisterInfoByName (ent->name); |
| if (ri) |
| ent->lldb_regno = ri->kinds[eRegisterKindLLDB]; |
| } |
| *initialized_flag = 1; |
| } |
| } |
| |
| // on initial construction we may not have a Thread so these have to remain |
| // uninitialized until we can get a RegisterContext to set up the register map table |
| if (*initialized_flag == 1) |
| { |
| uint32_t lldb_regno; |
| if (machine_regno_to_lldb_regno (m_machine_sp_regnum, lldb_regno)) |
| m_lldb_sp_regnum = lldb_regno; |
| if (machine_regno_to_lldb_regno (m_machine_fp_regnum, lldb_regno)) |
| m_lldb_fp_regnum = lldb_regno; |
| if (machine_regno_to_lldb_regno (m_machine_ip_regnum, lldb_regno)) |
| m_lldb_ip_regnum = lldb_regno; |
| } |
| |
| m_disasm_context = ::LLVMCreateDisasm(m_arch.GetTriple().getTriple().c_str(), |
| (void*)this, |
| /*TagType=*/1, |
| NULL, |
| NULL); |
| } |
| |
| AssemblyParse_x86::~AssemblyParse_x86 () |
| { |
| ::LLVMDisasmDispose(m_disasm_context); |
| } |
| |
| // This function expects an x86 native register number (i.e. the bits stripped out of the |
| // actual instruction), not an lldb register number. |
| |
| bool |
| AssemblyParse_x86::nonvolatile_reg_p (int machine_regno) |
| { |
| if (m_cpu == k_i386) |
| { |
| switch (machine_regno) { |
| case k_machine_ebx: |
| case k_machine_ebp: // not actually a nonvolatile but often treated as such by convention |
| case k_machine_esi: |
| case k_machine_edi: |
| case k_machine_esp: |
| return true; |
| default: |
| return false; |
| } |
| } |
| if (m_cpu == k_x86_64) |
| { |
| switch (machine_regno) { |
| case k_machine_rbx: |
| case k_machine_rsp: |
| case k_machine_rbp: // not actually a nonvolatile but often treated as such by convention |
| case k_machine_r12: |
| case k_machine_r13: |
| case k_machine_r14: |
| case k_machine_r15: |
| return true; |
| default: |
| return false; |
| } |
| } |
| return false; |
| } |
| |
| |
| // Macro to detect if this is a REX mode prefix byte. |
| #define REX_W_PREFIX_P(opcode) (((opcode) & (~0x5)) == 0x48) |
| |
| // The high bit which should be added to the source register number (the "R" bit) |
| #define REX_W_SRCREG(opcode) (((opcode) & 0x4) >> 2) |
| |
| // The high bit which should be added to the destination register number (the "B" bit) |
| #define REX_W_DSTREG(opcode) ((opcode) & 0x1) |
| |
| // pushq %rbp [0x55] |
| bool AssemblyParse_x86::push_rbp_pattern_p () { |
| uint8_t *p = m_cur_insn_bytes; |
| if (*p == 0x55) |
| return true; |
| return false; |
| } |
| |
| // pushq $0 ; the first instruction in start() [0x6a 0x00] |
| bool AssemblyParse_x86::push_0_pattern_p () |
| { |
| uint8_t *p = m_cur_insn_bytes; |
| if (*p == 0x6a && *(p + 1) == 0x0) |
| return true; |
| return false; |
| } |
| |
| // movq %rsp, %rbp [0x48 0x8b 0xec] or [0x48 0x89 0xe5] |
| // movl %esp, %ebp [0x8b 0xec] or [0x89 0xe5] |
| bool AssemblyParse_x86::mov_rsp_rbp_pattern_p () { |
| uint8_t *p = m_cur_insn_bytes; |
| if (m_wordsize == 8 && *p == 0x48) |
| p++; |
| if (*(p) == 0x8b && *(p + 1) == 0xec) |
| return true; |
| if (*(p) == 0x89 && *(p + 1) == 0xe5) |
| return true; |
| return false; |
| } |
| |
| // subq $0x20, %rsp |
| bool AssemblyParse_x86::sub_rsp_pattern_p (int& amount) { |
| uint8_t *p = m_cur_insn_bytes; |
| if (m_wordsize == 8 && *p == 0x48) |
| p++; |
| // 8-bit immediate operand |
| if (*p == 0x83 && *(p + 1) == 0xec) { |
| amount = (int8_t) *(p + 2); |
| return true; |
| } |
| // 32-bit immediate operand |
| if (*p == 0x81 && *(p + 1) == 0xec) { |
| amount = (int32_t) extract_4 (p + 2); |
| return true; |
| } |
| // Not handled: [0x83 0xc4] for imm8 with neg values |
| // [0x81 0xc4] for imm32 with neg values |
| return false; |
| } |
| |
| // pushq %rbx |
| // pushl $ebx |
| bool AssemblyParse_x86::push_reg_p (int& regno) { |
| uint8_t *p = m_cur_insn_bytes; |
| int regno_prefix_bit = 0; |
| // If we have a rex prefix byte, check to see if a B bit is set |
| if (m_wordsize == 8 && *p == 0x41) { |
| regno_prefix_bit = 1 << 3; |
| p++; |
| } |
| if (*p >= 0x50 && *p <= 0x57) { |
| regno = (*p - 0x50) | regno_prefix_bit; |
| return true; |
| } |
| return false; |
| } |
| |
| // Look for an instruction sequence storing a nonvolatile register |
| // on to the stack frame. |
| |
| // movq %rax, -0x10(%rbp) [0x48 0x89 0x45 0xf0] |
| // movl %eax, -0xc(%ebp) [0x89 0x45 0xf4] |
| bool AssemblyParse_x86::mov_reg_to_local_stack_frame_p (int& regno, int& rbp_offset) { |
| uint8_t *p = m_cur_insn_bytes; |
| int src_reg_prefix_bit = 0; |
| int target_reg_prefix_bit = 0; |
| |
| if (m_wordsize == 8 && REX_W_PREFIX_P (*p)) { |
| src_reg_prefix_bit = REX_W_SRCREG (*p) << 3; |
| target_reg_prefix_bit = REX_W_DSTREG (*p) << 3; |
| if (target_reg_prefix_bit == 1) { |
| // rbp/ebp don't need a prefix bit - we know this isn't the |
| // reg we care about. |
| return false; |
| } |
| p++; |
| } |
| |
| if (*p == 0x89) { |
| /* Mask off the 3-5 bits which indicate the destination register |
| if this is a ModR/M byte. */ |
| int opcode_destreg_masked_out = *(p + 1) & (~0x38); |
| |
| /* Is this a ModR/M byte with Mod bits 01 and R/M bits 101 |
| and three bits between them, e.g. 01nnn101 |
| We're looking for a destination of ebp-disp8 or ebp-disp32. */ |
| int immsize; |
| if (opcode_destreg_masked_out == 0x45) |
| immsize = 2; |
| else if (opcode_destreg_masked_out == 0x85) |
| immsize = 4; |
| else |
| return false; |
| |
| int offset = 0; |
| if (immsize == 2) |
| offset = (int8_t) *(p + 2); |
| if (immsize == 4) |
| offset = (uint32_t) extract_4 (p + 2); |
| if (offset > 0) |
| return false; |
| |
| regno = ((*(p + 1) >> 3) & 0x7) | src_reg_prefix_bit; |
| rbp_offset = offset > 0 ? offset : -offset; |
| return true; |
| } |
| return false; |
| } |
| |
| // ret [0xc9] or [0xc2 imm8] or [0xca imm8] |
| bool |
| AssemblyParse_x86::ret_pattern_p () |
| { |
| uint8_t *p = m_cur_insn_bytes; |
| if (*p == 0xc9 || *p == 0xc2 || *p == 0xca || *p == 0xc3) |
| return true; |
| return false; |
| } |
| |
| uint32_t |
| AssemblyParse_x86::extract_4 (uint8_t *b) |
| { |
| uint32_t v = 0; |
| for (int i = 3; i >= 0; i--) |
| v = (v << 8) | b[i]; |
| return v; |
| } |
| |
| bool |
| AssemblyParse_x86::machine_regno_to_lldb_regno (int machine_regno, uint32_t &lldb_regno) |
| { |
| struct regmap_ent *ent; |
| int count, i; |
| if (m_cpu == k_i386) |
| { |
| ent = i386_register_map; |
| count = size_of_i386_register_map; |
| } |
| else |
| { |
| ent = x86_64_register_map; |
| count = size_of_x86_64_register_map; |
| } |
| for (i = 0; i < count; i++, ent++) |
| { |
| if (ent->machine_regno == machine_regno) |
| if (ent->lldb_regno != -1) |
| { |
| lldb_regno = ent->lldb_regno; |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| bool |
| AssemblyParse_x86::instruction_length (Address addr, int &length) |
| { |
| const uint32_t max_op_byte_size = m_arch.GetMaximumOpcodeByteSize(); |
| llvm::SmallVector <uint8_t, 32> opcode_data; |
| opcode_data.resize (max_op_byte_size); |
| |
| if (!addr.IsValid()) |
| return false; |
| |
| const bool prefer_file_cache = true; |
| Error error; |
| Target *target = m_exe_ctx.GetTargetPtr(); |
| if (target->ReadMemory (addr, prefer_file_cache, opcode_data.data(), |
| max_op_byte_size, error) == static_cast<size_t>(-1)) |
| { |
| return false; |
| } |
| |
| char out_string[512]; |
| const addr_t pc = addr.GetFileAddress(); |
| const size_t inst_size = ::LLVMDisasmInstruction (m_disasm_context, |
| opcode_data.data(), |
| max_op_byte_size, |
| pc, // PC value |
| out_string, |
| sizeof(out_string)); |
| |
| length = inst_size; |
| return true; |
| } |
| |
| |
| bool |
| AssemblyParse_x86::get_non_call_site_unwind_plan (UnwindPlan &unwind_plan) |
| { |
| UnwindPlan::RowSP row(new UnwindPlan::Row); |
| int non_prologue_insn_count = 0; |
| m_cur_insn = m_func_bounds.GetBaseAddress (); |
| int current_func_text_offset = 0; |
| int current_sp_bytes_offset_from_cfa = 0; |
| UnwindPlan::Row::RegisterLocation initial_regloc; |
| Error error; |
| |
| if (!m_cur_insn.IsValid()) |
| { |
| return false; |
| } |
| |
| unwind_plan.SetPlanValidAddressRange (m_func_bounds); |
| unwind_plan.SetRegisterKind (eRegisterKindLLDB); |
| |
| // At the start of the function, find the CFA by adding wordsize to the SP register |
| row->SetOffset (current_func_text_offset); |
| row->SetCFARegister (m_lldb_sp_regnum); |
| row->SetCFAOffset (m_wordsize); |
| |
| // caller's stack pointer value before the call insn is the CFA address |
| initial_regloc.SetIsCFAPlusOffset (0); |
| row->SetRegisterInfo (m_lldb_sp_regnum, initial_regloc); |
| |
| // saved instruction pointer can be found at CFA - wordsize. |
| current_sp_bytes_offset_from_cfa = m_wordsize; |
| initial_regloc.SetAtCFAPlusOffset (-current_sp_bytes_offset_from_cfa); |
| row->SetRegisterInfo (m_lldb_ip_regnum, initial_regloc); |
| |
| unwind_plan.AppendRow (row); |
| |
| // Allocate a new Row, populate it with the existing Row contents. |
| UnwindPlan::Row *newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| |
| const bool prefer_file_cache = true; |
| |
| Target *target = m_exe_ctx.GetTargetPtr(); |
| while (m_func_bounds.ContainsFileAddress (m_cur_insn) && non_prologue_insn_count < 10) |
| { |
| int stack_offset, insn_len; |
| int machine_regno; // register numbers masked directly out of instructions |
| uint32_t lldb_regno; // register numbers in lldb's eRegisterKindLLDB numbering scheme |
| |
| if (!instruction_length (m_cur_insn, insn_len) || insn_len == 0 || insn_len > kMaxInstructionByteSize) |
| { |
| // An unrecognized/junk instruction |
| break; |
| } |
| if (target->ReadMemory (m_cur_insn, prefer_file_cache, m_cur_insn_bytes, |
| insn_len, error) == static_cast<size_t>(-1)) |
| { |
| // Error reading the instruction out of the file, stop scanning |
| break; |
| } |
| |
| if (push_rbp_pattern_p ()) |
| { |
| row->SetOffset (current_func_text_offset + insn_len); |
| current_sp_bytes_offset_from_cfa += m_wordsize; |
| row->SetCFAOffset (current_sp_bytes_offset_from_cfa); |
| UnwindPlan::Row::RegisterLocation regloc; |
| regloc.SetAtCFAPlusOffset (-row->GetCFAOffset()); |
| row->SetRegisterInfo (m_lldb_fp_regnum, regloc); |
| unwind_plan.AppendRow (row); |
| // Allocate a new Row, populate it with the existing Row contents. |
| newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| goto loopnext; |
| } |
| |
| if (mov_rsp_rbp_pattern_p ()) |
| { |
| row->SetOffset (current_func_text_offset + insn_len); |
| row->SetCFARegister (m_lldb_fp_regnum); |
| unwind_plan.AppendRow (row); |
| // Allocate a new Row, populate it with the existing Row contents. |
| newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| goto loopnext; |
| } |
| |
| // This is the start() function (or a pthread equivalent), it starts with a pushl $0x0 which puts the |
| // saved pc value of 0 on the stack. In this case we want to pretend we didn't see a stack movement at all -- |
| // normally the saved pc value is already on the stack by the time the function starts executing. |
| if (push_0_pattern_p ()) |
| { |
| goto loopnext; |
| } |
| |
| if (push_reg_p (machine_regno)) |
| { |
| current_sp_bytes_offset_from_cfa += m_wordsize; |
| bool need_to_push_row = false; |
| // the PUSH instruction has moved the stack pointer - if the CFA is set in terms of the stack pointer, |
| // we need to add a new row of instructions. |
| if (row->GetCFARegister() == static_cast<uint32_t>(m_lldb_sp_regnum)) |
| { |
| need_to_push_row = true; |
| row->SetCFAOffset (current_sp_bytes_offset_from_cfa); |
| } |
| // record where non-volatile (callee-saved, spilled) registers are saved on the stack |
| if (nonvolatile_reg_p (machine_regno) && machine_regno_to_lldb_regno (machine_regno, lldb_regno)) |
| { |
| need_to_push_row = true; |
| UnwindPlan::Row::RegisterLocation regloc; |
| regloc.SetAtCFAPlusOffset (-current_sp_bytes_offset_from_cfa); |
| row->SetRegisterInfo (lldb_regno, regloc); |
| } |
| if (need_to_push_row) |
| { |
| row->SetOffset (current_func_text_offset + insn_len); |
| unwind_plan.AppendRow (row); |
| // Allocate a new Row, populate it with the existing Row contents. |
| newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| } |
| goto loopnext; |
| } |
| |
| if (mov_reg_to_local_stack_frame_p (machine_regno, stack_offset) && nonvolatile_reg_p (machine_regno)) |
| { |
| if (machine_regno_to_lldb_regno (machine_regno, lldb_regno)) |
| { |
| row->SetOffset (current_func_text_offset + insn_len); |
| UnwindPlan::Row::RegisterLocation regloc; |
| regloc.SetAtCFAPlusOffset (-row->GetCFAOffset()); |
| row->SetRegisterInfo (lldb_regno, regloc); |
| unwind_plan.AppendRow (row); |
| // Allocate a new Row, populate it with the existing Row contents. |
| newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| goto loopnext; |
| } |
| } |
| |
| if (sub_rsp_pattern_p (stack_offset)) |
| { |
| current_sp_bytes_offset_from_cfa += stack_offset; |
| if (row->GetCFARegister() == static_cast<uint32_t>(m_lldb_sp_regnum)) |
| { |
| row->SetOffset (current_func_text_offset + insn_len); |
| row->SetCFAOffset (current_sp_bytes_offset_from_cfa); |
| unwind_plan.AppendRow (row); |
| // Allocate a new Row, populate it with the existing Row contents. |
| newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| } |
| goto loopnext; |
| } |
| |
| if (ret_pattern_p ()) |
| { |
| // we know where the end of the function is; set the limit on the PlanValidAddressRange |
| // in case our initial "high pc" value was overly large |
| // int original_size = m_func_bounds.GetByteSize(); |
| // int calculated_size = m_cur_insn.GetOffset() - m_func_bounds.GetBaseAddress().GetOffset() + insn_len + 1; |
| // m_func_bounds.SetByteSize (calculated_size); |
| // unwind_plan.SetPlanValidAddressRange (m_func_bounds); |
| break; |
| } |
| |
| // FIXME recognize the i386 picbase setup instruction sequence, |
| // 0x1f16: call 0x1f1b ; main + 11 at /private/tmp/a.c:3 |
| // 0x1f1b: popl %eax |
| // and record the temporary stack movements if the CFA is not expressed in terms of ebp. |
| |
| non_prologue_insn_count++; |
| loopnext: |
| m_cur_insn.SetOffset (m_cur_insn.GetOffset() + insn_len); |
| current_func_text_offset += insn_len; |
| } |
| |
| // Now look at the byte at the end of the AddressRange for a limited attempt at describing the |
| // epilogue. We're looking for the sequence |
| |
| // [ 0x5d ] mov %rbp, %rsp |
| // [ 0xc3 ] ret |
| // [ 0xe8 xx xx xx xx ] call __stack_chk_fail (this is sometimes the final insn in the function) |
| |
| // We want to add a Row describing how to unwind when we're stopped on the 'ret' instruction where the |
| // CFA is no longer defined in terms of rbp, but is now defined in terms of rsp like on function entry. |
| |
| uint64_t ret_insn_offset = LLDB_INVALID_ADDRESS; |
| Address end_of_fun(m_func_bounds.GetBaseAddress()); |
| end_of_fun.SetOffset (end_of_fun.GetOffset() + m_func_bounds.GetByteSize()); |
| |
| if (m_func_bounds.GetByteSize() > 7) |
| { |
| uint8_t bytebuf[7]; |
| Address last_seven_bytes(end_of_fun); |
| last_seven_bytes.SetOffset (last_seven_bytes.GetOffset() - 7); |
| if (target->ReadMemory (last_seven_bytes, prefer_file_cache, bytebuf, 7, |
| error) != static_cast<size_t>(-1)) |
| { |
| if (bytebuf[5] == 0x5d && bytebuf[6] == 0xc3) // mov, ret |
| { |
| ret_insn_offset = m_func_bounds.GetByteSize() - 1; |
| } |
| else if (bytebuf[0] == 0x5d && bytebuf[1] == 0xc3 && bytebuf[2] == 0xe8) // mov, ret, call |
| { |
| ret_insn_offset = m_func_bounds.GetByteSize() - 6; |
| } |
| } |
| } else if (m_func_bounds.GetByteSize() > 2) |
| { |
| uint8_t bytebuf[2]; |
| Address last_two_bytes(end_of_fun); |
| last_two_bytes.SetOffset (last_two_bytes.GetOffset() - 2); |
| if (target->ReadMemory (last_two_bytes, prefer_file_cache, bytebuf, 2, |
| error) != static_cast<size_t>(-1)) |
| { |
| if (bytebuf[0] == 0x5d && bytebuf[1] == 0xc3) // mov, ret |
| { |
| ret_insn_offset = m_func_bounds.GetByteSize() - 1; |
| } |
| } |
| } |
| |
| if (ret_insn_offset != LLDB_INVALID_ADDRESS) |
| { |
| // Create a fresh, empty Row and RegisterLocation - don't mention any other registers |
| UnwindPlan::RowSP epi_row(new UnwindPlan::Row); |
| UnwindPlan::Row::RegisterLocation epi_regloc; |
| |
| // When the ret instruction is about to be executed, here's our state |
| epi_row->SetOffset (ret_insn_offset); |
| epi_row->SetCFARegister (m_lldb_sp_regnum); |
| epi_row->SetCFAOffset (m_wordsize); |
| |
| // caller's stack pointer value before the call insn is the CFA address |
| epi_regloc.SetIsCFAPlusOffset (0); |
| epi_row->SetRegisterInfo (m_lldb_sp_regnum, epi_regloc); |
| |
| // saved instruction pointer can be found at CFA - wordsize |
| epi_regloc.SetAtCFAPlusOffset (-m_wordsize); |
| epi_row->SetRegisterInfo (m_lldb_ip_regnum, epi_regloc); |
| |
| unwind_plan.AppendRow (epi_row); |
| } |
| |
| unwind_plan.SetSourceName ("assembly insn profiling"); |
| unwind_plan.SetSourcedFromCompiler (eLazyBoolNo); |
| unwind_plan.SetUnwindPlanValidAtAllInstructions (eLazyBoolYes); |
| |
| return true; |
| } |
| |
| /* The "fast unwind plan" is valid for functions that follow the usual convention of |
| using the frame pointer register (ebp, rbp), i.e. the function prologue looks like |
| push %rbp [0x55] |
| mov %rsp,%rbp [0x48 0x89 0xe5] (this is a 2-byte insn seq on i386) |
| */ |
| |
| bool |
| AssemblyParse_x86::get_fast_unwind_plan (AddressRange& func, UnwindPlan &unwind_plan) |
| { |
| UnwindPlan::RowSP row(new UnwindPlan::Row); |
| UnwindPlan::Row::RegisterLocation pc_reginfo; |
| UnwindPlan::Row::RegisterLocation sp_reginfo; |
| UnwindPlan::Row::RegisterLocation fp_reginfo; |
| unwind_plan.SetRegisterKind (eRegisterKindLLDB); |
| |
| if (!func.GetBaseAddress().IsValid()) |
| return false; |
| |
| Target *target = m_exe_ctx.GetTargetPtr(); |
| |
| uint8_t bytebuf[4]; |
| Error error; |
| const bool prefer_file_cache = true; |
| if (target->ReadMemory (func.GetBaseAddress(), prefer_file_cache, bytebuf, |
| sizeof (bytebuf), error) == static_cast<size_t>(-1)) |
| return false; |
| |
| uint8_t i386_prologue[] = {0x55, 0x89, 0xe5}; |
| uint8_t x86_64_prologue[] = {0x55, 0x48, 0x89, 0xe5}; |
| int prologue_size; |
| |
| if (memcmp (bytebuf, i386_prologue, sizeof (i386_prologue)) == 0) |
| { |
| prologue_size = sizeof (i386_prologue); |
| } |
| else if (memcmp (bytebuf, x86_64_prologue, sizeof (x86_64_prologue)) == 0) |
| { |
| prologue_size = sizeof (x86_64_prologue); |
| } |
| else |
| { |
| return false; |
| } |
| |
| pc_reginfo.SetAtCFAPlusOffset (-m_wordsize); |
| row->SetRegisterInfo (m_lldb_ip_regnum, pc_reginfo); |
| |
| sp_reginfo.SetIsCFAPlusOffset (0); |
| row->SetRegisterInfo (m_lldb_sp_regnum, sp_reginfo); |
| |
| // Zero instructions into the function |
| row->SetCFARegister (m_lldb_sp_regnum); |
| row->SetCFAOffset (m_wordsize); |
| row->SetOffset (0); |
| unwind_plan.AppendRow (row); |
| UnwindPlan::Row *newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| |
| // push %rbp has executed - stack moved, rbp now saved |
| row->SetCFAOffset (2 * m_wordsize); |
| fp_reginfo.SetAtCFAPlusOffset (2 * -m_wordsize); |
| row->SetRegisterInfo (m_lldb_fp_regnum, fp_reginfo); |
| row->SetOffset (1); |
| unwind_plan.AppendRow (row); |
| |
| newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| |
| // mov %rsp, %rbp has executed |
| row->SetCFARegister (m_lldb_fp_regnum); |
| row->SetCFAOffset (2 * m_wordsize); |
| row->SetOffset (prologue_size); /// 3 or 4 bytes depending on arch |
| unwind_plan.AppendRow (row); |
| |
| newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| |
| unwind_plan.SetPlanValidAddressRange (func); |
| unwind_plan.SetSourceName ("fast unwind assembly profiling"); |
| unwind_plan.SetSourcedFromCompiler (eLazyBoolNo); |
| unwind_plan.SetUnwindPlanValidAtAllInstructions (eLazyBoolNo); |
| return true; |
| } |
| |
| bool |
| AssemblyParse_x86::find_first_non_prologue_insn (Address &address) |
| { |
| m_cur_insn = m_func_bounds.GetBaseAddress (); |
| if (!m_cur_insn.IsValid()) |
| { |
| return false; |
| } |
| |
| const bool prefer_file_cache = true; |
| Target *target = m_exe_ctx.GetTargetPtr(); |
| while (m_func_bounds.ContainsFileAddress (m_cur_insn)) |
| { |
| Error error; |
| int insn_len, offset, regno; |
| if (!instruction_length (m_cur_insn, insn_len) || insn_len > kMaxInstructionByteSize || insn_len == 0) |
| { |
| // An error parsing the instruction, i.e. probably data/garbage - stop scanning |
| break; |
| } |
| if (target->ReadMemory (m_cur_insn, prefer_file_cache, m_cur_insn_bytes, |
| insn_len, error) == static_cast<size_t>(-1)) |
| { |
| // Error reading the instruction out of the file, stop scanning |
| break; |
| } |
| |
| if (push_rbp_pattern_p () || mov_rsp_rbp_pattern_p () || sub_rsp_pattern_p (offset) |
| || push_reg_p (regno) || mov_reg_to_local_stack_frame_p (regno, offset)) |
| { |
| m_cur_insn.SetOffset (m_cur_insn.GetOffset() + insn_len); |
| continue; |
| } |
| |
| // Unknown non-prologue instruction - stop scanning |
| break; |
| } |
| |
| address = m_cur_insn; |
| return true; |
| } |
| |
| |
| |
| |
| |
| |
| //----------------------------------------------------------------------------------------------- |
| // UnwindAssemblyParser_x86 method definitions |
| //----------------------------------------------------------------------------------------------- |
| |
| UnwindAssembly_x86::UnwindAssembly_x86 (const ArchSpec &arch, int cpu) : |
| lldb_private::UnwindAssembly(arch), |
| m_cpu(cpu), |
| m_arch(arch) |
| { |
| } |
| |
| |
| UnwindAssembly_x86::~UnwindAssembly_x86 () |
| { |
| } |
| |
| bool |
| UnwindAssembly_x86::GetNonCallSiteUnwindPlanFromAssembly (AddressRange& func, Thread& thread, UnwindPlan& unwind_plan) |
| { |
| ExecutionContext exe_ctx (thread.shared_from_this()); |
| AssemblyParse_x86 asm_parse(exe_ctx, m_cpu, m_arch, func); |
| return asm_parse.get_non_call_site_unwind_plan (unwind_plan); |
| } |
| |
| bool |
| UnwindAssembly_x86::GetFastUnwindPlan (AddressRange& func, Thread& thread, UnwindPlan &unwind_plan) |
| { |
| ExecutionContext exe_ctx (thread.shared_from_this()); |
| AssemblyParse_x86 asm_parse(exe_ctx, m_cpu, m_arch, func); |
| return asm_parse.get_fast_unwind_plan (func, unwind_plan); |
| } |
| |
| bool |
| UnwindAssembly_x86::FirstNonPrologueInsn (AddressRange& func, const ExecutionContext &exe_ctx, Address& first_non_prologue_insn) |
| { |
| AssemblyParse_x86 asm_parse(exe_ctx, m_cpu, m_arch, func); |
| return asm_parse.find_first_non_prologue_insn (first_non_prologue_insn); |
| } |
| |
| UnwindAssembly * |
| UnwindAssembly_x86::CreateInstance (const ArchSpec &arch) |
| { |
| const llvm::Triple::ArchType cpu = arch.GetMachine (); |
| if (cpu == llvm::Triple::x86) |
| return new UnwindAssembly_x86 (arch, k_i386); |
| else if (cpu == llvm::Triple::x86_64) |
| return new UnwindAssembly_x86 (arch, k_x86_64); |
| return NULL; |
| } |
| |
| |
| //------------------------------------------------------------------ |
| // PluginInterface protocol in UnwindAssemblyParser_x86 |
| //------------------------------------------------------------------ |
| |
| ConstString |
| UnwindAssembly_x86::GetPluginName() |
| { |
| return GetPluginNameStatic(); |
| } |
| |
| |
| uint32_t |
| UnwindAssembly_x86::GetPluginVersion() |
| { |
| return 1; |
| } |
| |
| void |
| UnwindAssembly_x86::Initialize() |
| { |
| PluginManager::RegisterPlugin (GetPluginNameStatic(), |
| GetPluginDescriptionStatic(), |
| CreateInstance); |
| } |
| |
| void |
| UnwindAssembly_x86::Terminate() |
| { |
| PluginManager::UnregisterPlugin (CreateInstance); |
| } |
| |
| |
| lldb_private::ConstString |
| UnwindAssembly_x86::GetPluginNameStatic() |
| { |
| static ConstString g_name("x86"); |
| return g_name; |
| } |
| |
| const char * |
| UnwindAssembly_x86::GetPluginDescriptionStatic() |
| { |
| return "i386 and x86_64 assembly language profiler plugin."; |
| } |
