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eb9dc1341da5aaf76e330331abf26b84f10d7169
pstrace/framework/sysutils.cpp
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/*
* sysutils.cpp
*
* Created on: Dec 28, 2019
* Author: nnosov
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <unistd.h>
#include <limits.h>
#include <elfutils/libdwfl.h>
#include <cxxabi.h>
#include <execinfo.h>
#include <dwarf.h>
#include <inttypes.h>
#include "sysutils.h"
#include "logger/log.h"
#define USEI_LIBUNWIND
#ifdef USEI_LIBUNWIND
#include <libunwind.h>
#endif
#include "common.h"
#include "dwarf_operations.h"
// dwfl_addrsegment() possibly can be used to check address validity
// dwarf_getattrs() allows to enumerate all DIE attributes
// dwarf_getfuncs() allows to enumerate functions within CU
typedef struct __reginfo {
__reginfo() {
regname[0] = 0;
regno = -1;
}
char regname[1024];
int regno;
} reginfo;
int regname_callback (void *arg, int regno, const char *setname, const char *prefix, const char *regname, int bits, int type)
{
reginfo* info = (reginfo*)arg;
if(info->regno == regno) {
snprintf(info->regname, sizeof(info->regname), "%s %s%s", setname, prefix, regname);
}
return 0;
}
/*
int reginfo_callback (void *arg, int regno, const char *setname, const char *prefix, const char *regname, int bits, int type)
{
reginfo* info = (reginfo*)arg;
//logger->Log(SEVERITY_DEBUG, "%s: info_reg = 0x%hhX, reg = 0x%hhX", __FUNCTION__, info->regno, regno);
if(info->regno == regno) {
snprintf(info->regname, sizeof(info->regname), "%s %s%s", setname, prefix, regname);
Dwarf_Op ops_mem[3];
Dwarf_Op* ops;
size_t nops;
int ret = dwarf_frame_register(frame, info->regno, ops_mem, &ops, &nops);
if(ret != 0) {
logger->Log(SEVERITY_DEBUG, "Failed to get CFI expression for register %s", info->regname);
return 0;
}
if(nops == 0 && ops == ops_mem) {
logger->Log(SEVERITY_DEBUG, "CFI expression for register %s is UNDEFINED", info->regname);
return 0;
}
if(nops == 0 && ops == NULL) {
logger->Log(SEVERITY_DEBUG, "CFI expression for register %s is SAME VALUE", info->regname);
return 0;
}
logger->Log(SEVERITY_DEBUG, "Found CFI expression for register %s, number of expressions: %d", info->regname, nops);
for(size_t i = 0; i < nops; ++i) {
logger->Log(SEVERITY_DEBUG, "\t[%d] operation: 0x%hhX, operand1: 0x%lX, operand2: 0x%lx, offset: 0x%lX", i, ops[i].atom, ops[i].number, ops[i].number2, ops[i].offset);
}
}
return 0;
}
*/
/*
void print_framereg(int regno)
{
Dwarf_Op ops_mem[3];
Dwarf_Op* ops;
size_t nops;
int ret = dwarf_frame_register(frame, regno, ops_mem, &ops, &nops);
if(ret != 0) {
logger->Log(SEVERITY_DEBUG, "Failed to get CFI expression for register 0x%hhX", regno);
return;
}
if(nops == 0 && ops == ops_mem) {
logger->Log(SEVERITY_DEBUG, "CFI expression for register 0x%hhX is UNDEFINED", regno);
return;
}
if(nops == 0 && ops == NULL) {
logger->Log(SEVERITY_DEBUG, "CFI expression for register 0x%hhX is SAME VALUE", regno);
return;
}
logger->Log(SEVERITY_DEBUG, "Found CFI expression for register 0x%hhX, number of expressions: %d", regno, nops);
for(size_t i = 0; i < nops; ++i) {
logger->Log(SEVERITY_DEBUG, "\t[%d] operation: 0x%hhX, operand1: 0x%lX, operand2: 0x%lx, offset: 0x%lX", i, ops[i].atom, ops[i].number, ops[i].number2, ops[i].offset);
}
}
*/
bool __pst_parameter::print_dwarf()
{
if(types.size()) {
if(!is_return) {
ctx->print("%s %s = 0x%lX", types[0].c_str(), name.c_str(), value);
} else {
ctx->print("%s", types[0].c_str());
}
} else {
ctx->print("%s = 0x%lX", name.c_str(), value);
}
return true;
}
bool __pst_parameter::handle_type(Dwarf_Attribute* param, bool is_return)
{
Dwarf_Attribute attr_mem;
Dwarf_Attribute* attr;
// get DIE of return type
Dwarf_Die ret_die;
if(!dwarf_formref_die(param, &ret_die)) {
ctx->log(SEVERITY_ERROR, "Failed to get parameter DIE");
return false;
}
switch (dwarf_tag(&ret_die)) {
case DW_TAG_base_type: {
// get Size attribute and it's value
Dwarf_Word size = 0;
attr = dwarf_attr(&ret_die, DW_AT_byte_size, &attr_mem);
if(attr) {
dwarf_formudata(attr, &size);
}
ctx->log(SEVERITY_DEBUG, "base type '%s'(%lu)", dwarf_diename(&ret_die), size);
types.push_back(dwarf_diename(&ret_die));
break;
}
case DW_TAG_array_type:
ctx->log(SEVERITY_DEBUG, "array type");
types.push_back("[]");
break;
case DW_TAG_structure_type:
ctx->log(SEVERITY_DEBUG, "structure type");
types.push_back("struct");
break;
case DW_TAG_union_type:
ctx->log(SEVERITY_DEBUG, "union type");
types.push_back("union");
break;
case DW_TAG_class_type:
ctx->log(SEVERITY_DEBUG, "class type");
types.push_back("class");
break;
case DW_TAG_pointer_type:
ctx->log(SEVERITY_DEBUG, "pointer type");
types.push_back("*");
break;
case DW_TAG_enumeration_type:
ctx->log(SEVERITY_DEBUG, "enumeration type");
types.push_back("enum");
break;
case DW_TAG_const_type:
ctx->log(SEVERITY_DEBUG, "constant type");
types.push_back("const");
break;
case DW_TAG_subroutine_type:
ctx->log(SEVERITY_DEBUG, "subroutine type");
break;
case DW_TAG_typedef:
ctx->log(SEVERITY_DEBUG, "typedef '%s' type", dwarf_diename(&ret_die));
types.push_back(dwarf_diename(&ret_die));
break;
default:
ctx->log(SEVERITY_WARNING, "Unknown 0x%X tag type", dwarf_tag(&ret_die));
break;
}
attr = dwarf_attr(&ret_die, DW_AT_type, &attr_mem);
if(attr) {
return handle_type(attr);
}
return true;
}
bool __pst_parameter::handle_dwarf(Dwarf_Die* result)
{
die = result;
Dwarf_Attribute attr_mem;
Dwarf_Attribute* attr;
name = dwarf_diename(result);
is_variable = (dwarf_tag(result) == DW_TAG_variable);
// Get reference to attribute type of the parameter/variable
attr = dwarf_attr(result, DW_AT_type, &attr_mem);
ctx->log(SEVERITY_DEBUG, "Handle '%s' %s", name.c_str(), dwarf_tag(result) == DW_TAG_formal_parameter ? "parameter" : "variable");
if(attr) {
handle_type(attr);
}
Dwarf_Addr pc;
unw_get_reg(&ctx->cursor, UNW_REG_IP, &pc);
Dwarf_Addr offset = pc - ctx->base_addr;
dwarf_stack stack(ctx);
// determine location of parameter in stack/heap or CPU registers
attr = dwarf_attr(result, DW_AT_location, &attr_mem);
if(attr) {
if(dwarf_hasform(attr, DW_FORM_exprloc)) {
Dwarf_Op *expr;
size_t exprlen;
if(dwarf_getlocation(attr, &expr, &exprlen) == 0) {
char str[1024]; str[0] = 0;
ctx->print_expr_block (expr, exprlen, str, sizeof(str), attr);
if(stack.calc_expression(expr, exprlen, attr)) {
if(stack.get_value(value)) {
ctx->log(SEVERITY_DEBUG, "DW_AT_location expression: \"%s\" ==> 0x%lX", str, value);
} else {
ctx->log(SEVERITY_ERROR, "Failed to get value of calculated DW_AT_location expression: %s", str);
}
} else {
ctx->log(SEVERITY_ERROR, "Failed to calculate DW_AT_location expression: %s", str);
}
}
} else if(dwarf_hasform(attr, DW_FORM_sec_offset)) {
Dwarf_Addr base, start, end;
ptrdiff_t off = 0;
Dwarf_Op *expr;
size_t exprlen;
// handle list of possible locations of parameter
for(int i = 0; (off = dwarf_getlocations (attr, off, &base, &start, &end, &expr, &exprlen)) > 0; ++i) {
if(offset >= start && offset <= end) {
// actual location, try to calculate Location expression and retrieve value of parameter
char str[1024]; str[0] = 0;
ctx->print_expr_block (expr, exprlen, str, sizeof(str), attr);
if(stack.calc_expression(expr, exprlen, attr)) {
if(stack.get_value(value)) {
ctx->log(SEVERITY_DEBUG, "Location list expression: [%d] (low_offset: 0x%" PRIx64 ", high_offset: 0x%" PRIx64"), \"%s\" ==> 0x%lX", i, start, end, str, value);
} else {
ctx->log(SEVERITY_DEBUG, "Failed to get value of calculated Location list expression: [%d] (low_offset: 0x%" PRIx64 ", high_offset: 0x%" PRIx64 "), \"%s\" ==> 0x%lX",
i, start, end, str, value);
}
} else {
ctx->log(SEVERITY_DEBUG, "Failed to calculate Location list expression: [%d] (low_offset: 0x%" PRIx64 ", high_offset: 0x%" PRIx64 "), \"%s\" ==> 0x%lX",
i, start, end, str, value);
}
} else {
// Location skipped due to don't match current PC offset
}
}
} else {
ctx->log(SEVERITY_WARNING, "Unknown attribute form = 0x%X, code = 0x%X, ", attr->form, attr->code);
}
}
return true;
}
bool __pst_function::print_dwarf()
{
//std::vector<std::string>::const_iterator param;
//for (param = params.begin(); param != params.end(); ++param) {
bool first = true; bool start_variable = false;
for(auto param : params) {
if(param.is_return) {
// print return value, function name and start list of parameters
param.print_dwarf();
ctx->print(" %s(", name.c_str());
continue;
}
if(param.is_variable) {
if(!start_variable) {
ctx->print(")\n");
ctx->print("{\n");
start_variable = true;
}
ctx->print("\t");
param.print_dwarf();
ctx->print(";\n");
} else {
if(first) {
first = false;
} else {
ctx->print(", ");
}
param.print_dwarf();
}
}
if(!start_variable) {
ctx->print(");\n");
} else {
ctx->print("}\n");
}
return true;
}
bool __pst_function::handle_dwarf(Dwarf_Die* d)
{
die = d;
Dwarf_Attribute attr_mem;
Dwarf_Attribute* attr;
// get list of offsets from process base address of continuous memory ranges where function's code resides
// if(dwarf_haspc(d, pc)) {
dwarf_lowpc(d, &lowpc);
dwarf_highpc(d, &highpc);
// } else {
// ctx->log(SEVERITY_ERROR, "Function's '%s' DIE hasn't definitions of memory offsets of function's code", dwarf_diename(d));
// return false;
// }
unw_proc_info_t info;
unw_get_proc_info(&ctx->cursor, &info);
unw_word_t sp;
unw_get_reg(&ctx->cursor, UNW_REG_SP, &sp);
ctx->log(SEVERITY_DEBUG, "Found function in debug info. name = %s(...), PC = 0x%lX, LOW_PC = 0x%lX, HIGH_PC = 0x%lX, offset from base address: 0x%lX, BASE_PC = 0x%lX, offset from start of function: 0x%lX, stack address: 0x%lX",
dwarf_diename(d), pc, lowpc, highpc, pc - ctx->base_addr, info.start_ip, info.start_ip - ctx->base_addr, sp);
// determine function's stack frame base
attr = dwarf_attr(die, DW_AT_frame_base, &attr_mem);
if(attr) {
if(dwarf_hasform(attr, DW_FORM_exprloc)) {
Dwarf_Op *expr;
size_t exprlen;
if (dwarf_getlocation (attr, &expr, &exprlen) == 0) {
char str[1024]; str[0] = 0;
ctx->print_expr_block (expr, exprlen, str, sizeof(str), attr);
dwarf_stack stack(ctx);
if(stack.calc_expression(expr, exprlen, attr)) {
uint64_t value;
if(stack.get_value(value)) {
ctx->log(SEVERITY_DEBUG, "DW_AT_framebase expression: \"%s\"==> 0x%lX", str, value);
} else {
ctx->log(SEVERITY_ERROR, "Failed to get value of calculated DW_AT_framebase expression: %s", str);
}
} else {
ctx->log(SEVERITY_ERROR, "Failed to calculate DW_AT_framebase expression: %s", str);
}
} else {
ctx->log(SEVERITY_WARNING, "Unknown attribute form = 0x%X, code = 0x%X", attr->form, attr->code);
}
}
}
// Get reference to return attribute type of the function
// may be to use dwfl_module_return_value_location() instead
pst_parameter ret_p(ctx); ret_p.is_return = true;
attr = dwarf_attr(die, DW_AT_type, &attr_mem);
if(attr) {
ctx->log(SEVERITY_DEBUG, "Handle return parameter");
if(ret_p.handle_type(attr, true)) {
params.push_back(ret_p);
}
} else {
ret_p.types.push_back("void");
params.push_back(ret_p);
ctx->log(SEVERITY_DEBUG, "return attr name = 'void(0)'");
}
Dwarf_Die result;
if(dwarf_child(die, &result) != 0)
return false;
// went through parameters and local variables of the function
do {
pst_parameter param(ctx);
switch (dwarf_tag(&result)) {
case DW_TAG_formal_parameter:
case DW_TAG_variable:
if(param.handle_dwarf(&result)) {
params.push_back(param);
}
break;
// case DW_TAG_inlined_subroutine:
// /* Recurse further down */
// HandleFunction(&result, dwarf_diename(&result));
// break;
default:
break;
}
} while(dwarf_siblingof(&result, &result) == 0);
return true;
}
bool __pst_function::unwind(Dwfl* dwfl, Dwfl_Module* module, Dwarf_Addr addr)
{
pc = addr;
Dwfl_Line *line = dwfl_getsrc(dwfl, addr);
if(line != NULL) {
int nline;
Dwarf_Addr addr;
const char* filename = dwfl_lineinfo (line, &addr, &nline, NULL, NULL, NULL);
if(filename) {
const char* str = strrchr(filename, '/');
if(str && *str != 0) {
str++;
} else {
str = filename;
}
ctx->print("%s:%d", str, nline);
} else {
ctx->print("%p", (void*)addr);
}
} else {
ctx->print("%p", (void*)addr);
}
const char* addrname = dwfl_module_addrname(module, addr);
char* demangle_name = NULL;
if(addrname) {
int status;
demangle_name = abi::__cxa_demangle(addrname, NULL, NULL, &status);
char* function_name = NULL;
if(asprintf(&function_name, "%s%s", demangle_name ? demangle_name : addrname, demangle_name ? "" : "()") == -1) {
ctx->log(SEVERITY_ERROR, "Failed to allocate memory");
return false;
}
ctx->print(" --> %s", function_name);
char* str = strchr(function_name, '(');
if(str) {
*str = 0;
}
name = function_name;
free(function_name);
}
if(demangle_name) {
free(demangle_name);
}
return true;
}
bool __pst_handler::get_frame()
{
// get CFI (Call Frame Information) for current module
// from handle_cfi()
Dwarf_Addr mod_bias = 0;
Dwarf_CFI* cfi = dwfl_module_eh_cfi(module, &mod_bias);
//Dwarf_CFI* cfi = dwfl_module_dwarf_cfi(module, &mod_bias);
if(!cfi) {
ctx.log(SEVERITY_INFO, "Cannot find CFI for module");
return false;
}
// get frame of CFI for address
int result = dwarf_cfi_addrframe (cfi, addr - mod_bias, &frame);
if (result == 0) {
// get frame information
ctx.log(SEVERITY_INFO, "Found CFI frame for module");
Dwarf_Addr start = addr;
Dwarf_Addr end = addr;
bool signalp;
int ra_regno = dwarf_frame_info (frame, &start, &end, &signalp);
if(ra_regno >= 0) {
start += mod_bias;
end += mod_bias;
}
ctx.log(SEVERITY_DEBUG, "Per '.eh_frame' info has %#" PRIx64 " => [%#" PRIx64 ", %#" PRIx64 "] in_signal = %s", addr, start, end, signalp ? "true" : "false");
if (ra_regno < 0)
ctx.log(SEVERITY_DEBUG, "return address register unavailable (%s)", dwarf_errmsg(0));
else {
reginfo info; info.regno = ra_regno;
dwfl_module_register_names(module, regname_callback, &info);
ctx.log(SEVERITY_DEBUG, "return address in reg%u%s ==> %s", ra_regno, signalp ? " (signal frame)" : "", info.regname);
}
// finally get CFA (Canonical Frame Address)
// Point cfa_ops to dummy to match print_detail expectations.
// (nops == 0 && cfa_ops != NULL => "undefined")
Dwarf_Op dummy;
Dwarf_Op *cfa_ops = &dummy;
size_t cfa_nops;
result = dwarf_frame_cfa(frame, &cfa_ops, &cfa_nops);
char str[1024]; str[0] = 0;
ctx.print_expr_block (cfa_ops, cfa_nops, str, sizeof(str));
ctx.log(SEVERITY_INFO, "Found CFA expression: %s", str);
//print_detail (result, cfa_ops, cfa_nops, mod_bias, "\tCFA ");
}
return true;
}
bool __pst_handler::get_dwarf_function(pst_function& fun)
{
Dwarf_Addr mod_cu = 0;
// get CU(Compilation Unit) debug definition
Dwarf_Die* cdie = dwfl_module_addrdie(module, addr, &mod_cu);
//Dwarf_Die* cdie = dwfl_addrdie(dwfl, addr, &mod_bias);
if(!cdie) {
ctx.log(SEVERITY_INFO, "Failed to find DWARF DIE for address %X", addr);
return false;
}
if(dwarf_tag(cdie) != DW_TAG_compile_unit) {
ctx.log(SEVERITY_DEBUG, "Skipping non-cu die. DWARF tag: 0x%X, name = %s", dwarf_tag(cdie), dwarf_diename(cdie));
return false;
}
Dwarf_Die result;
if(dwarf_child(cdie, &result)) {
ctx.log(SEVERITY_ERROR, "No child DIE found for CU %s", dwarf_diename(cdie));
return false;
}
bool nret = false;
do {
int tag = dwarf_tag(&result);
if(tag == DW_TAG_subprogram || tag == DW_TAG_entry_point || tag == DW_TAG_inlined_subroutine) {
if(!strcmp(fun.name.c_str(), dwarf_diename(&result))) {
return fun.handle_dwarf(&result);
}
}
} while(dwarf_siblingof(&result, &result) == 0);
return nret;
}
void __pst_handler::print_dwarf()
{
ctx.offset = 0;
ctx.print("DWARF-based stack trace information:\n");
for(auto function : functions) {
function.print_dwarf();
ctx.print("\n");
}
}
char *debuginfo_path = NULL;
Dwfl_Callbacks callbacks = {
.find_elf = dwfl_linux_proc_find_elf,
.find_debuginfo = dwfl_standard_find_debuginfo,
.section_address = dwfl_offline_section_address,
.debuginfo_path = &debuginfo_path,
};
#include <dlfcn.h>
bool __pst_handler::unwind()
{
#ifdef REG_RIP // x86_64
caller = (void *) ctx.hcontext->uc_mcontext.gregs[REG_RIP];
#elif defined(REG_EIP) // x86_32
caller_address = (void *) uctx->uc_mcontext.gregs[REG_EIP]);
#elif defined(__arm__)
caller_address = (void *) uctx->uc_mcontext.arm_pc);
#elif defined(__aarch64__)
caller_address = (void *) uctx->uc_mcontext.pc);
#elif defined(__ppc__) || defined(__powerpc) || defined(__powerpc__) || defined(__POWERPC__)
caller_address = (void *) uctx->uc_mcontext.regs->nip);
#elif defined(__s390x__)
caller_address = (void *) uctx->uc_mcontext.psw.addr);
#elif defined(__APPLE__) && defined(__x86_64__)
caller_address = (void *) uctx->uc_mcontext->__ss.__rip);
#else
# error "unknown architecture!"
#endif
handle = dlopen(NULL, RTLD_NOW);
Dl_info info;
dladdr(caller, &info);
ctx.base_addr = (uint64_t)info.dli_fbase;
ctx.log(SEVERITY_INFO, "Process address information: base address: %p, object name: %s", info.dli_fbase, info.dli_fname);
int skipped = 0;
#ifndef USEI_LIBUNWIND
int size = 0;
void * array[50];
size = backtrace(array, 50);
for(int i = 0; i < size && array[i] != caller_address; ++i, ++skipped);
print("Stack trace(caller = %p. Total stack frames: %d, skipped: %d):\n", caller_address, size, skipped);
#else
unw_word_t pc;
unw_getcontext(&ctx.context);
unw_init_local(&ctx.cursor, &ctx.context);
while (unw_step(&ctx.cursor) > 0) {
unw_get_reg(&ctx.cursor, UNW_REG_IP, &pc);
if(pc == (uint64_t)caller) {
break;
} else {
++skipped;
}
}
ctx.print("Stack trace(caller = %p. Skipped stack frames: %d):\n", caller, skipped);
#endif
dwfl = dwfl_begin(&callbacks);
if(dwfl == NULL) {
ctx.print("Failed to initialize libdw session for parse stack frames");
return false;
}
if(dwfl_linux_proc_report(dwfl, getpid()) != 0 || dwfl_report_end(dwfl, NULL, NULL) !=0) {
ctx.print("Failed to parse debug section of executable");
return false;
}
#ifndef USEI_LIBUNWIND
for (int i = skipped, idx = 0; i < size ; ++i, ++idx) {
print("[%-2d] ", idx);
Dwarf_Addr addr = (uintptr_t)array[i];
#else
for (int i = skipped, idx = 0; true ; ++i, ++idx) {
unw_get_reg(&ctx.cursor, UNW_REG_IP, &pc);
addr = pc;
ctx.print("[%-2d] ", idx);
#endif
module = dwfl_addrmodule(dwfl, addr);
//get_frame();
pst_function fun(&ctx);
if(fun.unwind(dwfl, module, pc)) {
if(get_dwarf_function(fun)) {
functions.push_back(fun);
}
}
ctx.print("\n");
#ifdef USEI_LIBUNWIND
if(unw_step(&ctx.cursor) <= 0) {
break;
}
#endif
}
// for(int op = DW_OP_breg0; op <= DW_OP_breg16; op++ ) {
// printf("{0x%X, 0x%X, \"%s\"},\n", op, op - DW_OP_breg0, unw_regname(op - DW_OP_breg0));
// }
return true;
}
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