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Use _dl_find_object over dladdr when possible in object resolution, it's so much faster

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Jeremy 2023-11-20 23:36:55 -06:00
parent 9113cc5ffc
commit 87cd24438b
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GPG Key ID: B4C8300FEC395042
1 changed files with 39 additions and 4 deletions
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43
src/binary/object.hpp
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@ -17,6 +17,9 @@
#else
#include "elf.hpp"
#endif
#if CPPTRACE_HAS_DL_FIND_OBJECT
#include <link.h>
#endif
#elif IS_WINDOWS
#include <windows.h>
#include "pe.hpp"
@ -61,6 +64,39 @@ namespace detail {
}
}
#endif
#if CPPTRACE_HAS_DL_FIND_OBJECT
inline std::vector<object_frame> get_frames_object_info(const std::vector<frame_ptr>& addrs) {
// Use _dl_find_object when we can, it's orders of magnitude faster
std::vector<object_frame> frames;
frames.reserve(addrs.size());
for(const frame_ptr addr : addrs) {
object_frame frame;
frame.raw_address = addr;
frame.object_address = 0;
dl_find_object result;
if(_dl_find_object(reinterpret_cast<void*>(addr), &result) == 0) { // thread safe
if(result.dlfo_link_map->l_name != nullptr && result.dlfo_link_map->l_name[0] != 0) {
frame.object_path = result.dlfo_link_map->l_name;
} else {
// empty l_name, this means it's the currently running executable
// TODO: Caching and proper handling
char buffer[CPPTRACE_PATH_MAX + 1]{};
auto res = readlink("/proc/self/exe", buffer, CPPTRACE_PATH_MAX);
if(res == -1) {
// error handling?
} else {
frame.object_path = buffer;
}
}
frame.object_address = addr
- reinterpret_cast<std::uintptr_t>(result.dlfo_map_start)
+ get_module_image_base(frame.object_path);
}
frames.push_back(frame);
}
return frames;
}
#else
// aladdr queries are needed to get pre-ASLR addresses and targets to run addr2line on
inline std::vector<object_frame> get_frames_object_info(const std::vector<frame_ptr>& addrs) {
// reference: https://github.com/bminor/glibc/blob/master/debug/backtracesyms.c
@ -72,17 +108,16 @@ namespace detail {
frame.raw_address = addr;
frame.object_address = 0;
if(dladdr(reinterpret_cast<void*>(addr), &info)) { // thread safe
// dli_sname and dli_saddr are only present with -rdynamic, sname will be included
// but we don't really need dli_saddr
frame.object_path = info.dli_fname;
frame.object_address = addr
- reinterpret_cast<std::uintptr_t>(info.dli_fbase)
+ get_module_image_base(info.dli_fname);
- reinterpret_cast<std::uintptr_t>(info.dli_fbase)
+ get_module_image_base(info.dli_fname);
}
frames.push_back(frame);
}
return frames;
}
#endif
#else
inline std::string get_module_name(HMODULE handle) {
static std::mutex mutex;