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Diffstat (limited to 'libunwind/src/DwarfInstructions.hpp')
-rw-r--r-- | libunwind/src/DwarfInstructions.hpp | 760 |
1 files changed, 760 insertions, 0 deletions
diff --git a/libunwind/src/DwarfInstructions.hpp b/libunwind/src/DwarfInstructions.hpp new file mode 100644 index 00000000000..99737e0b66c --- /dev/null +++ b/libunwind/src/DwarfInstructions.hpp @@ -0,0 +1,760 @@ +//===-------------------------- DwarfInstructions.hpp ---------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is dual licensed under the MIT and the University of Illinois Open +// Source Licenses. See LICENSE.TXT for details. +// +// +// Processor specific interpretation of dwarf unwind info. +// +//===----------------------------------------------------------------------===// + +#ifndef __DWARF_INSTRUCTIONS_HPP__ +#define __DWARF_INSTRUCTIONS_HPP__ + +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> + +#include "dwarf2.h" +#include "AddressSpace.hpp" +#include "Registers.hpp" +#include "DwarfParser.hpp" +#include "config.h" + + +namespace libunwind { + + +/// DwarfInstructions maps abtract dwarf unwind instructions to a particular +/// architecture +template <typename A, typename R> +class DwarfInstructions { +public: + typedef typename A::pint_t pint_t; + typedef typename A::sint_t sint_t; + + static int stepWithDwarf(A &addressSpace, pint_t pc, pint_t fdeStart, + R ®isters); + +private: + + enum { + DW_X86_64_RET_ADDR = 16 + }; + + enum { + DW_X86_RET_ADDR = 8 + }; + + typedef typename CFI_Parser<A>::RegisterLocation RegisterLocation; + typedef typename CFI_Parser<A>::PrologInfo PrologInfo; + typedef typename CFI_Parser<A>::FDE_Info FDE_Info; + typedef typename CFI_Parser<A>::CIE_Info CIE_Info; + + static pint_t evaluateExpression(pint_t expression, A &addressSpace, + const R ®isters, + pint_t initialStackValue); + static pint_t getSavedRegister(A &addressSpace, const R ®isters, + pint_t cfa, const RegisterLocation &savedReg); + static double getSavedFloatRegister(A &addressSpace, const R ®isters, + pint_t cfa, const RegisterLocation &savedReg); + static v128 getSavedVectorRegister(A &addressSpace, const R ®isters, + pint_t cfa, const RegisterLocation &savedReg); + + static pint_t getCFA(A &addressSpace, const PrologInfo &prolog, + const R ®isters) { + if (prolog.cfaRegister != 0) + return (pint_t)((sint_t)registers.getRegister((int)prolog.cfaRegister) + + prolog.cfaRegisterOffset); + if (prolog.cfaExpression != 0) + return evaluateExpression((pint_t)prolog.cfaExpression, addressSpace, + registers, 0); + assert(0 && "getCFA(): unknown location"); + __builtin_unreachable(); + } +}; + + +template <typename A, typename R> +typename A::pint_t DwarfInstructions<A, R>::getSavedRegister( + A &addressSpace, const R ®isters, pint_t cfa, + const RegisterLocation &savedReg) { + switch (savedReg.location) { + case CFI_Parser<A>::kRegisterInCFA: + return addressSpace.getP(cfa + (pint_t)savedReg.value); + + case CFI_Parser<A>::kRegisterAtExpression: + return addressSpace.getP( + evaluateExpression((pint_t)savedReg.value, addressSpace, + registers, cfa)); + + case CFI_Parser<A>::kRegisterIsExpression: + return evaluateExpression((pint_t)savedReg.value, addressSpace, + registers, cfa); + + case CFI_Parser<A>::kRegisterInRegister: + return registers.getRegister((int)savedReg.value); + + case CFI_Parser<A>::kRegisterUnused: + case CFI_Parser<A>::kRegisterOffsetFromCFA: + // FIX ME + break; + } + _LIBUNWIND_ABORT("unsupported restore location for register"); +} + +template <typename A, typename R> +double DwarfInstructions<A, R>::getSavedFloatRegister( + A &addressSpace, const R ®isters, pint_t cfa, + const RegisterLocation &savedReg) { + switch (savedReg.location) { + case CFI_Parser<A>::kRegisterInCFA: + return addressSpace.getDouble(cfa + (pint_t)savedReg.value); + + case CFI_Parser<A>::kRegisterAtExpression: + return addressSpace.getDouble( + evaluateExpression((pint_t)savedReg.value, addressSpace, + registers, cfa)); + + case CFI_Parser<A>::kRegisterIsExpression: + case CFI_Parser<A>::kRegisterUnused: + case CFI_Parser<A>::kRegisterOffsetFromCFA: + case CFI_Parser<A>::kRegisterInRegister: + // FIX ME + break; + } + _LIBUNWIND_ABORT("unsupported restore location for float register"); +} + +template <typename A, typename R> +v128 DwarfInstructions<A, R>::getSavedVectorRegister( + A &addressSpace, const R ®isters, pint_t cfa, + const RegisterLocation &savedReg) { + switch (savedReg.location) { + case CFI_Parser<A>::kRegisterInCFA: + return addressSpace.getVector(cfa + (pint_t)savedReg.value); + + case CFI_Parser<A>::kRegisterAtExpression: + return addressSpace.getVector( + evaluateExpression((pint_t)savedReg.value, addressSpace, + registers, cfa)); + + case CFI_Parser<A>::kRegisterIsExpression: + case CFI_Parser<A>::kRegisterUnused: + case CFI_Parser<A>::kRegisterOffsetFromCFA: + case CFI_Parser<A>::kRegisterInRegister: + // FIX ME + break; + } + _LIBUNWIND_ABORT("unsupported restore location for vector register"); +} + +template <typename A, typename R> +int DwarfInstructions<A, R>::stepWithDwarf(A &addressSpace, pint_t pc, + pint_t fdeStart, R ®isters) { + FDE_Info fdeInfo; + CIE_Info cieInfo; + if (CFI_Parser<A>::decodeFDE(addressSpace, fdeStart, &fdeInfo, + &cieInfo) == NULL) { + PrologInfo prolog; + if (CFI_Parser<A>::parseFDEInstructions(addressSpace, fdeInfo, cieInfo, pc, + &prolog)) { + // get pointer to cfa (architecture specific) + pint_t cfa = getCFA(addressSpace, prolog, registers); + + // restore registers that dwarf says were saved + R newRegisters = registers; + pint_t returnAddress = 0; + const int lastReg = R::lastDwarfRegNum(); + assert((int)CFI_Parser<A>::kMaxRegisterNumber > lastReg && + "register range too large"); + assert(lastReg <= (int)cieInfo.returnAddressRegister && + "register range does not contain return address register"); + for (int i = 0; i <= lastReg; ++i) { + if (prolog.savedRegisters[i].location != + CFI_Parser<A>::kRegisterUnused) { + if (registers.validFloatRegister(i)) + newRegisters.setFloatRegister( + i, getSavedFloatRegister(addressSpace, registers, cfa, + prolog.savedRegisters[i])); + else if (registers.validVectorRegister(i)) + newRegisters.setVectorRegister( + i, getSavedVectorRegister(addressSpace, registers, cfa, + prolog.savedRegisters[i])); + else if (i == (int)cieInfo.returnAddressRegister) + returnAddress = getSavedRegister(addressSpace, registers, cfa, + prolog.savedRegisters[i]); + else if (registers.validRegister(i)) + newRegisters.setRegister( + i, getSavedRegister(addressSpace, registers, cfa, + prolog.savedRegisters[i])); + else + return UNW_EBADREG; + } + } + + // By definition, the CFA is the stack pointer at the call site, so + // restoring SP means setting it to CFA. + newRegisters.setSP(cfa); + + // Return address is address after call site instruction, so setting IP to + // that does simualates a return. + newRegisters.setIP(returnAddress); + + // Simulate the step by replacing the register set with the new ones. + registers = newRegisters; + + return UNW_STEP_SUCCESS; + } + } + return UNW_EBADFRAME; +} + +template <typename A, typename R> +typename A::pint_t +DwarfInstructions<A, R>::evaluateExpression(pint_t expression, A &addressSpace, + const R ®isters, + pint_t initialStackValue) { + const bool log = false; + pint_t p = expression; + pint_t expressionEnd = expression + 20; // temp, until len read + pint_t length = (pint_t)addressSpace.getULEB128(p, expressionEnd); + expressionEnd = p + length; + if (log) + fprintf(stderr, "evaluateExpression(): length=%" PRIu64 "\n", + (uint64_t)length); + pint_t stack[100]; + pint_t *sp = stack; + *(++sp) = initialStackValue; + + while (p < expressionEnd) { + if (log) { + for (pint_t *t = sp; t > stack; --t) { + fprintf(stderr, "sp[] = 0x%" PRIx64 "\n", (uint64_t)(*t)); + } + } + uint8_t opcode = addressSpace.get8(p++); + sint_t svalue, svalue2; + pint_t value; + uint32_t reg; + switch (opcode) { + case DW_OP_addr: + // push immediate address sized value + value = addressSpace.getP(p); + p += sizeof(pint_t); + *(++sp) = value; + if (log) + fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value); + break; + + case DW_OP_deref: + // pop stack, dereference, push result + value = *sp--; + *(++sp) = addressSpace.getP(value); + if (log) + fprintf(stderr, "dereference 0x%" PRIx64 "\n", (uint64_t)value); + break; + + case DW_OP_const1u: + // push immediate 1 byte value + value = addressSpace.get8(p); + p += 1; + *(++sp) = value; + if (log) + fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value); + break; + + case DW_OP_const1s: + // push immediate 1 byte signed value + svalue = (int8_t) addressSpace.get8(p); + p += 1; + *(++sp) = (pint_t)svalue; + if (log) + fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)svalue); + break; + + case DW_OP_const2u: + // push immediate 2 byte value + value = addressSpace.get16(p); + p += 2; + *(++sp) = value; + if (log) + fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value); + break; + + case DW_OP_const2s: + // push immediate 2 byte signed value + svalue = (int16_t) addressSpace.get16(p); + p += 2; + *(++sp) = (pint_t)svalue; + if (log) + fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)svalue); + break; + + case DW_OP_const4u: + // push immediate 4 byte value + value = addressSpace.get32(p); + p += 4; + *(++sp) = value; + if (log) + fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value); + break; + + case DW_OP_const4s: + // push immediate 4 byte signed value + svalue = (int32_t)addressSpace.get32(p); + p += 4; + *(++sp) = (pint_t)svalue; + if (log) + fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)svalue); + break; + + case DW_OP_const8u: + // push immediate 8 byte value + value = (pint_t)addressSpace.get64(p); + p += 8; + *(++sp) = value; + if (log) + fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value); + break; + + case DW_OP_const8s: + // push immediate 8 byte signed value + value = (pint_t)addressSpace.get64(p); + p += 8; + *(++sp) = value; + if (log) + fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value); + break; + + case DW_OP_constu: + // push immediate ULEB128 value + value = (pint_t)addressSpace.getULEB128(p, expressionEnd); + *(++sp) = value; + if (log) + fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value); + break; + + case DW_OP_consts: + // push immediate SLEB128 value + svalue = (sint_t)addressSpace.getSLEB128(p, expressionEnd); + *(++sp) = (pint_t)svalue; + if (log) + fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)svalue); + break; + + case DW_OP_dup: + // push top of stack + value = *sp; + *(++sp) = value; + if (log) + fprintf(stderr, "duplicate top of stack\n"); + break; + + case DW_OP_drop: + // pop + --sp; + if (log) + fprintf(stderr, "pop top of stack\n"); + break; + + case DW_OP_over: + // dup second + value = sp[-1]; + *(++sp) = value; + if (log) + fprintf(stderr, "duplicate second in stack\n"); + break; + + case DW_OP_pick: + // pick from + reg = addressSpace.get8(p); + p += 1; + value = sp[-reg]; + *(++sp) = value; + if (log) + fprintf(stderr, "duplicate %d in stack\n", reg); + break; + + case DW_OP_swap: + // swap top two + value = sp[0]; + sp[0] = sp[-1]; + sp[-1] = value; + if (log) + fprintf(stderr, "swap top of stack\n"); + break; + + case DW_OP_rot: + // rotate top three + value = sp[0]; + sp[0] = sp[-1]; + sp[-1] = sp[-2]; + sp[-2] = value; + if (log) + fprintf(stderr, "rotate top three of stack\n"); + break; + + case DW_OP_xderef: + // pop stack, dereference, push result + value = *sp--; + *sp = *((pint_t*)value); + if (log) + fprintf(stderr, "x-dereference 0x%" PRIx64 "\n", (uint64_t)value); + break; + + case DW_OP_abs: + svalue = (sint_t)*sp; + if (svalue < 0) + *sp = (pint_t)(-svalue); + if (log) + fprintf(stderr, "abs\n"); + break; + + case DW_OP_and: + value = *sp--; + *sp &= value; + if (log) + fprintf(stderr, "and\n"); + break; + + case DW_OP_div: + svalue = (sint_t)(*sp--); + svalue2 = (sint_t)*sp; + *sp = (pint_t)(svalue2 / svalue); + if (log) + fprintf(stderr, "div\n"); + break; + + case DW_OP_minus: + value = *sp--; + *sp = *sp - value; + if (log) + fprintf(stderr, "minus\n"); + break; + + case DW_OP_mod: + svalue = (sint_t)(*sp--); + svalue2 = (sint_t)*sp; + *sp = (pint_t)(svalue2 % svalue); + if (log) + fprintf(stderr, "module\n"); + break; + + case DW_OP_mul: + svalue = (sint_t)(*sp--); + svalue2 = (sint_t)*sp; + *sp = (pint_t)(svalue2 * svalue); + if (log) + fprintf(stderr, "mul\n"); + break; + + case DW_OP_neg: + *sp = 0 - *sp; + if (log) + fprintf(stderr, "neg\n"); + break; + + case DW_OP_not: + svalue = (sint_t)(*sp); + *sp = (pint_t)(~svalue); + if (log) + fprintf(stderr, "not\n"); + break; + + case DW_OP_or: + value = *sp--; + *sp |= value; + if (log) + fprintf(stderr, "or\n"); + break; + + case DW_OP_plus: + value = *sp--; + *sp += value; + if (log) + fprintf(stderr, "plus\n"); + break; + + case DW_OP_plus_uconst: + // pop stack, add uelb128 constant, push result + *sp += addressSpace.getULEB128(p, expressionEnd); + if (log) + fprintf(stderr, "add constant\n"); + break; + + case DW_OP_shl: + value = *sp--; + *sp = *sp << value; + if (log) + fprintf(stderr, "shift left\n"); + break; + + case DW_OP_shr: + value = *sp--; + *sp = *sp >> value; + if (log) + fprintf(stderr, "shift left\n"); + break; + + case DW_OP_shra: + value = *sp--; + svalue = (sint_t)*sp; + *sp = (pint_t)(svalue >> value); + if (log) + fprintf(stderr, "shift left arithmetric\n"); + break; + + case DW_OP_xor: + value = *sp--; + *sp ^= value; + if (log) + fprintf(stderr, "xor\n"); + break; + + case DW_OP_skip: + svalue = (int16_t) addressSpace.get16(p); + p += 2; + p = (pint_t)((sint_t)p + svalue); + if (log) + fprintf(stderr, "skip %" PRIu64 "\n", (uint64_t)svalue); + break; + + case DW_OP_bra: + svalue = (int16_t) addressSpace.get16(p); + p += 2; + if (*sp--) + p = (pint_t)((sint_t)p + svalue); + if (log) + fprintf(stderr, "bra %" PRIu64 "\n", (uint64_t)svalue); + break; + + case DW_OP_eq: + value = *sp--; + *sp = (*sp == value); + if (log) + fprintf(stderr, "eq\n"); + break; + + case DW_OP_ge: + value = *sp--; + *sp = (*sp >= value); + if (log) + fprintf(stderr, "ge\n"); + break; + + case DW_OP_gt: + value = *sp--; + *sp = (*sp > value); + if (log) + fprintf(stderr, "gt\n"); + break; + + case DW_OP_le: + value = *sp--; + *sp = (*sp <= value); + if (log) + fprintf(stderr, "le\n"); + break; + + case DW_OP_lt: + value = *sp--; + *sp = (*sp < value); + if (log) + fprintf(stderr, "lt\n"); + break; + + case DW_OP_ne: + value = *sp--; + *sp = (*sp != value); + if (log) + fprintf(stderr, "ne\n"); + break; + + case DW_OP_lit0: + case DW_OP_lit1: + case DW_OP_lit2: + case DW_OP_lit3: + case DW_OP_lit4: + case DW_OP_lit5: + case DW_OP_lit6: + case DW_OP_lit7: + case DW_OP_lit8: + case DW_OP_lit9: + case DW_OP_lit10: + case DW_OP_lit11: + case DW_OP_lit12: + case DW_OP_lit13: + case DW_OP_lit14: + case DW_OP_lit15: + case DW_OP_lit16: + case DW_OP_lit17: + case DW_OP_lit18: + case DW_OP_lit19: + case DW_OP_lit20: + case DW_OP_lit21: + case DW_OP_lit22: + case DW_OP_lit23: + case DW_OP_lit24: + case DW_OP_lit25: + case DW_OP_lit26: + case DW_OP_lit27: + case DW_OP_lit28: + case DW_OP_lit29: + case DW_OP_lit30: + case DW_OP_lit31: + value = static_cast<pint_t>(opcode - DW_OP_lit0); + *(++sp) = value; + if (log) + fprintf(stderr, "push literal 0x%" PRIx64 "\n", (uint64_t)value); + break; + + case DW_OP_reg0: + case DW_OP_reg1: + case DW_OP_reg2: + case DW_OP_reg3: + case DW_OP_reg4: + case DW_OP_reg5: + case DW_OP_reg6: + case DW_OP_reg7: + case DW_OP_reg8: + case DW_OP_reg9: + case DW_OP_reg10: + case DW_OP_reg11: + case DW_OP_reg12: + case DW_OP_reg13: + case DW_OP_reg14: + case DW_OP_reg15: + case DW_OP_reg16: + case DW_OP_reg17: + case DW_OP_reg18: + case DW_OP_reg19: + case DW_OP_reg20: + case DW_OP_reg21: + case DW_OP_reg22: + case DW_OP_reg23: + case DW_OP_reg24: + case DW_OP_reg25: + case DW_OP_reg26: + case DW_OP_reg27: + case DW_OP_reg28: + case DW_OP_reg29: + case DW_OP_reg30: + case DW_OP_reg31: + reg = static_cast<uint32_t>(opcode - DW_OP_reg0); + *(++sp) = registers.getRegister((int)reg); + if (log) + fprintf(stderr, "push reg %d\n", reg); + break; + + case DW_OP_regx: + reg = static_cast<uint32_t>(addressSpace.getULEB128(p, expressionEnd)); + *(++sp) = registers.getRegister((int)reg); + if (log) + fprintf(stderr, "push reg %d + 0x%" PRIx64 "\n", reg, (uint64_t)svalue); + break; + + case DW_OP_breg0: + case DW_OP_breg1: + case DW_OP_breg2: + case DW_OP_breg3: + case DW_OP_breg4: + case DW_OP_breg5: + case DW_OP_breg6: + case DW_OP_breg7: + case DW_OP_breg8: + case DW_OP_breg9: + case DW_OP_breg10: + case DW_OP_breg11: + case DW_OP_breg12: + case DW_OP_breg13: + case DW_OP_breg14: + case DW_OP_breg15: + case DW_OP_breg16: + case DW_OP_breg17: + case DW_OP_breg18: + case DW_OP_breg19: + case DW_OP_breg20: + case DW_OP_breg21: + case DW_OP_breg22: + case DW_OP_breg23: + case DW_OP_breg24: + case DW_OP_breg25: + case DW_OP_breg26: + case DW_OP_breg27: + case DW_OP_breg28: + case DW_OP_breg29: + case DW_OP_breg30: + case DW_OP_breg31: + reg = static_cast<uint32_t>(opcode - DW_OP_breg0); + svalue = (sint_t)addressSpace.getSLEB128(p, expressionEnd); + svalue += static_cast<sint_t>(registers.getRegister((int)reg)); + *(++sp) = (pint_t)(svalue); + if (log) + fprintf(stderr, "push reg %d + 0x%" PRIx64 "\n", reg, (uint64_t)svalue); + break; + + case DW_OP_bregx: + reg = static_cast<uint32_t>(addressSpace.getULEB128(p, expressionEnd)); + svalue = (sint_t)addressSpace.getSLEB128(p, expressionEnd); + svalue += static_cast<sint_t>(registers.getRegister((int)reg)); + *(++sp) = (pint_t)(svalue); + if (log) + fprintf(stderr, "push reg %d + 0x%" PRIx64 "\n", reg, (uint64_t)svalue); + break; + + case DW_OP_fbreg: + _LIBUNWIND_ABORT("DW_OP_fbreg not implemented"); + break; + + case DW_OP_piece: + _LIBUNWIND_ABORT("DW_OP_piece not implemented"); + break; + + case DW_OP_deref_size: + // pop stack, dereference, push result + value = *sp--; + switch (addressSpace.get8(p++)) { + case 1: + value = addressSpace.get8(value); + break; + case 2: + value = addressSpace.get16(value); + break; + case 4: + value = addressSpace.get32(value); + break; + case 8: + value = (pint_t)addressSpace.get64(value); + break; + default: + _LIBUNWIND_ABORT("DW_OP_deref_size with bad size"); + } + *(++sp) = value; + if (log) + fprintf(stderr, "sized dereference 0x%" PRIx64 "\n", (uint64_t)value); + break; + + case DW_OP_xderef_size: + case DW_OP_nop: + case DW_OP_push_object_addres: + case DW_OP_call2: + case DW_OP_call4: + case DW_OP_call_ref: + default: + _LIBUNWIND_ABORT("dwarf opcode not implemented"); + } + + } + if (log) + fprintf(stderr, "expression evaluates to 0x%" PRIx64 "\n", (uint64_t)*sp); + return *sp; +} + + + +} // namespace libunwind + +#endif // __DWARF_INSTRUCTIONS_HPP__ |