cpptrace/src/binary/safe_dl.cpp

77 lines
2.6 KiB
C++

#include "binary/safe_dl.hpp"
#include "utils/common.hpp"
#include "utils/utils.hpp"
#include "platform/program_name.hpp"
#include <string>
#include <vector>
#include <mutex>
#include <unordered_map>
#include <cstring>
#include <iostream>
#ifdef CPPTRACE_HAS_DL_FIND_OBJECT
#if IS_LINUX || IS_APPLE
#include <unistd.h>
#include <dlfcn.h>
#include <link.h>
#endif
namespace cpptrace {
namespace detail {
void get_safe_object_frame(frame_ptr address, safe_object_frame* out) {
out->raw_address = address;
dl_find_object result;
if(_dl_find_object(reinterpret_cast<void*>(address), &result) == 0) { // thread-safe, signal-safe
out->address_relative_to_object_start = address - to_frame_ptr(result.dlfo_link_map->l_addr);
if(result.dlfo_link_map->l_name != nullptr && result.dlfo_link_map->l_name[0] != 0) {
std::size_t path_length = std::strlen(result.dlfo_link_map->l_name);
std::memcpy(
out->object_path,
result.dlfo_link_map->l_name,
std::min(path_length + 1, std::size_t(CPPTRACE_PATH_MAX + 1))
);
} else {
// empty l_name, this means it's the currently running executable
memset(out->object_path, 0, CPPTRACE_PATH_MAX + 1);
// signal-safe
auto res = readlink("/proc/self/exe", out->object_path, CPPTRACE_PATH_MAX);
if(res == -1) {
// error handling?
}
// TODO: Special handling for /proc/pid/exe unlink edge case
}
} else {
// std::cout<<"error"<<std::endl;
out->address_relative_to_object_start = 0;
out->object_path[0] = 0;
}
// TODO: Handle this part of the documentation?
// The address can be a code address or data address. On architectures using function descriptors, no attempt is
// made to decode the function descriptor. Depending on how these descriptors are implemented, _dl_find_object
// may return the object that defines the function descriptor (and not the object that contains the code
// implementing the function), or fail to find any object at all.
}
bool has_get_safe_object_frame() {
return true;
}
}
}
#else
namespace cpptrace {
namespace detail {
void get_safe_object_frame(frame_ptr address, safe_object_frame* out) {
out->raw_address = address;
out->address_relative_to_object_start = 0;
out->object_path[0] = 0;
}
bool has_get_safe_object_frame() {
return false;
}
}
}
#endif