/*
* Copyright (c) Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stratosphere.hpp>
#include "diag_symbol_impl.hpp"
#define PACKAGE "stratosphere"
#define PACKAGE_VERSION STRINGIFY(ATMOSPHERE_RELEASE_VERSION_MAJOR.ATMOSPHERE_RELEASE_VERSION_MINOR.ATMOSPHERE_RELEASE_VERSION_MICRO)
#if defined(ATMOSPHERE_OS_LINUX)
#include <bfd.h>
#include <unistd.h>
#include <dlfcn.h>
#include <link.h>
extern "C" char __init_array_start;
#endif
#include <cxxabi.h>
namespace ams::diag::impl {
namespace {
class BfdHelper {
private:
bfd *m_handle;
asymbol **m_symbol;
size_t m_num_symbol;
size_t m_num_func_symbol;
const char *m_module_name;
uintptr_t m_module_address;
size_t m_module_size;
private:
BfdHelper() : m_handle(nullptr), m_symbol(nullptr), m_module_name(nullptr) {
/* Get the current executable name. */
char exe_path[4_KB] = {};
GetExecutablePath(exe_path, sizeof(exe_path));
/* Open bfd. */
bfd *b = ::bfd_openr(exe_path, 0);
if (b == nullptr) {
return;
}
auto bfd_guard = SCOPE_GUARD { ::bfd_close(b); };
/* Check the format. */
if (!::bfd_check_format(b, bfd_object)) {
return;
}
/* Verify the file has symbols. */
if ((bfd_get_file_flags(b) & HAS_SYMS) == 0) {
return;
}
/* Read the symbols. */
unsigned int _;
void *symbol_table;
s64 num_symbols = bfd_read_minisymbols(b, false, std::addressof(symbol_table), std::addressof(_));
if (num_symbols == 0) {
num_symbols = bfd_read_minisymbols(b, true, std::addressof(symbol_table), std::addressof(_));
if (num_symbols < 0) {
return;
}
}
/* We successfully got the symbol table. */
bfd_guard.Cancel();
m_handle = b;
m_symbol = reinterpret_cast<asymbol **>(symbol_table);
m_num_symbol = static_cast<size_t>(num_symbols);
/* Sort the symbol table. */
std::sort(m_symbol + 0, m_symbol + m_num_symbol, [] (asymbol *lhs, asymbol *rhs) {
const bool l_func = (lhs->flags & BSF_FUNCTION);
const bool r_func = (rhs->flags & BSF_FUNCTION);
if (l_func == r_func) {
return bfd_asymbol_value(lhs) < bfd_asymbol_value(rhs);
} else {
return l_func;
}
});
/* Determine number of function symbols. */
m_num_func_symbol = 0;
for (size_t i = 0; i < m_num_symbol; ++i) {
if ((m_symbol[i]->flags & BSF_FUNCTION) == 0) {
m_num_func_symbol = i;
break;
}
}
for (int i = std::strlen(exe_path) - 1; i >= 0; --i) {
if (exe_path[i] == '/' || exe_path[i] == '\\') {
m_module_name = strdup(exe_path + i + 1);
break;
}
}
/* Get our module base/size. */
#if defined(ATMOSPHERE_OS_LINUX)
{
m_module_address = _r_debug.r_map->l_addr;
m_module_size = reinterpret_cast<uintptr_t>(std::addressof(__init_array_start)) - m_module_address;
}
#endif
}
~BfdHelper() {
if (m_symbol != nullptr) {
std::free(m_symbol);
}
if (m_handle != nullptr) {
::bfd_close(m_handle);
}
}
public:
static BfdHelper &GetInstance() {
AMS_FUNCTION_LOCAL_STATIC(BfdHelper, s_bfd_helper_instance);
return s_bfd_helper_instance;
}
private:
size_t GetSymbolSizeImpl(asymbol **symbol) const {
/* Do our best to guess. */
const auto vma = bfd_asymbol_value(*symbol);
if (symbol != m_symbol + m_num_func_symbol - 1) {
return bfd_asymbol_value(*(symbol + 1)) - vma;
} else {
const auto *sec = (*symbol)->section;
return (sec->vma + sec->size) - vma;
}
}
std::ptrdiff_t GetSymbolAddressDisplacement(uintptr_t address) const {
std::ptrdiff_t displacement = 0;
if (m_module_address <= address && address < m_module_address + m_module_size) {
displacement = m_module_address;
}
return displacement;
}
asymbol **GetBestSymbol(uintptr_t address) const {
/* Adjust the symbol address. */
address -= this->GetSymbolAddressDisplacement(address);
asymbol **best_symbol = std::lower_bound(m_symbol + 0, m_symbol + m_num_func_symbol, address, [](asymbol *lhs, uintptr_t rhs) {
return bfd_asymbol_value(lhs) < rhs;
});
if (best_symbol == m_symbol + m_num_func_symbol) {
return nullptr;
}
if (bfd_asymbol_value(*best_symbol) != address && best_symbol > m_symbol) {
--best_symbol;
}
const auto vma = bfd_asymbol_value(*best_symbol);
const auto end = vma + this->GetSymbolSizeImpl(best_symbol);
if (vma <= address && address < end) {
return best_symbol;
} else {
return nullptr;
}
}
public:
uintptr_t GetSymbolName(char *dst, size_t dst_size, uintptr_t address) const {
/* Get the symbol. */
auto **symbol = this->GetBestSymbol(address);
if (symbol == nullptr) {
return 0;
}
/* Print the symbol. */
const char *name = bfd_asymbol_name(*symbol);
int cpp_name_status = 0;
if (char *demangled = abi::__cxa_demangle(name, nullptr, 0, std::addressof(cpp_name_status)); cpp_name_status == 0) {
AMS_ASSERT(demangled != nullptr);
util::TSNPrintf(dst, dst_size, "%s", demangled);
std::free(demangled);
} else {
util::TSNPrintf(dst, dst_size, "%s", name);
}
return bfd_asymbol_value(*symbol) + this->GetSymbolAddressDisplacement(address);
}
size_t GetSymbolSize(uintptr_t address) const {
/* Get the symbol. */
auto **symbol = this->GetBestSymbol(address);
if (symbol == nullptr) {
return 0;
}
return this->GetSymbolSizeImpl(symbol);
}
private:
static void GetExecutablePath(char *dst, size_t dst_size) {
#if defined(ATMOSPHERE_OS_LINUX)
{
if (::readlink("/proc/self/exe", dst, dst_size) == -1) {
dst[0] = 0;
return;
}
}
#else
#error "Unknown OS for BfdHelper GetExecutablePath"
#endif
}
};
}
uintptr_t GetSymbolNameImpl(char *dst, size_t dst_size, uintptr_t address) {
return BfdHelper::GetInstance().GetSymbolName(dst, dst_size, address);
}
size_t GetSymbolSizeImpl(uintptr_t address) {
return BfdHelper::GetInstance().GetSymbolSize(address);
}
}