mirror of
https://github.com/matrix-construct/construct
synced 2024-06-09 13:38:55 +02:00
133 lines
2.9 KiB
C++
133 lines
2.9 KiB
C++
// Matrix Construct
|
|
//
|
|
// Copyright (C) Matrix Construct Developers, Authors & Contributors
|
|
// Copyright (C) 2016-2019 Jason Volk <jason@zemos.net>
|
|
//
|
|
// Permission to use, copy, modify, and/or distribute this software for any
|
|
// purpose with or without fee is hereby granted, provided that the above
|
|
// copyright notice and this permission notice is present in all copies. The
|
|
// full license for this software is available in the LICENSE file.
|
|
|
|
// This file is platform specific. It is conditionally compiled and included
|
|
// in libircd glibc+ELF supporting environments. Do not rely on these
|
|
// definitions being available on all platforms.
|
|
|
|
#include <RB_INC_DLFCN_H
|
|
#include <RB_INC_LINK_H
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// mods/ldso.h
|
|
//
|
|
|
|
bool
|
|
ircd::mods::ldso::for_each(const link_name_closure &closure)
|
|
{
|
|
return !for_each(link_map_closure{[&closure]
|
|
(struct link_map &map)
|
|
{
|
|
return closure(map.l_name);
|
|
}});
|
|
}
|
|
|
|
bool
|
|
ircd::mods::ldso::for_each(const link_map_closure &closure)
|
|
{
|
|
auto *map
|
|
{
|
|
reinterpret_cast<struct link_map *>(::dlopen(NULL, RTLD_NOLOAD|RTLD_LAZY))
|
|
};
|
|
|
|
if(unlikely(!map))
|
|
throw error
|
|
{
|
|
::dlerror()
|
|
};
|
|
|
|
for(; map; map = map->l_next)
|
|
if(!closure(*map))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Symbolic dl-error redefinition to throw our C++ exception for the symbol
|
|
// lookup failure, during the lazy binding, directly from the callsite. THIS IS
|
|
// BETTER than the default glibc/elf/dl behavior of terminating the program.
|
|
//
|
|
// We probably need asynchronous-unwind-tables for an exception to safely
|
|
// transit from here through libdl and out of a random PLT slot. non-call-
|
|
// exceptions does not appear to be necessary, at least for FUNC symbols.
|
|
//
|
|
|
|
// glibc/sysdeps/generic/ldsodefs.h
|
|
struct dl_exception
|
|
{
|
|
const char *objname;
|
|
const char *errstring;
|
|
char *message_buffer;
|
|
};
|
|
|
|
extern "C" void
|
|
_dl_exception_free(struct dl_exception *)
|
|
__attribute__ ((nonnull(1)));
|
|
|
|
extern "C" void
|
|
__attribute__((noreturn))
|
|
_dl_signal_exception(int errcode,
|
|
struct dl_exception *e,
|
|
const char *occasion)
|
|
{
|
|
const ircd::unwind free
|
|
{
|
|
std::bind(_dl_exception_free, e)
|
|
};
|
|
|
|
ircd::log::derror
|
|
{
|
|
ircd::mods::log, "dynamic linker (%d) %s in `%s' :%s",
|
|
errcode,
|
|
occasion,
|
|
e->objname,
|
|
e->errstring
|
|
};
|
|
|
|
throw ircd::mods::error
|
|
{
|
|
"%s in %s (%d) %s",
|
|
occasion,
|
|
e->objname,
|
|
errcode,
|
|
e->errstring,
|
|
};
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// symbolic dlsym hook
|
|
//
|
|
#ifdef IRCD_MODS_HOOK_DLSYM
|
|
|
|
extern "C" void *
|
|
__libc_dlsym(void *, const char *);
|
|
|
|
extern "C" void *
|
|
dlsym(void *const handle,
|
|
const char *const symbol)
|
|
{
|
|
#ifdef RB_DEBUG_MODS_HOOK_DLSYM
|
|
ircd::log::debug
|
|
{
|
|
ircd::mods::log, "handle:%p symbol lookup '%s'",
|
|
handle,
|
|
symbol
|
|
};
|
|
#endif
|
|
|
|
return __libc_dlsym(handle, symbol);
|
|
}
|
|
|
|
#endif IRCD_MODS_HOOK_DLSYM
|