glibc/dlfcn/dlinfo.c
Florian Weimer d056c21213 dlfcn: Implement the RTLD_DI_PHDR request type for dlinfo
The information is theoretically available via dl_iterate_phdr as
well, but that approach is very slow if there are many shared
objects.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@rehdat.com>
2022-04-29 17:00:53 +02:00

122 lines
3.0 KiB
C

/* dlinfo -- Get information from the dynamic linker.
Copyright (C) 2003-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <dlfcn.h>
#include <link.h>
#include <ldsodefs.h>
#include <libintl.h>
#include <dl-tls.h>
#include <shlib-compat.h>
struct dlinfo_args
{
void *handle;
int request;
void *arg;
/* This is the value that is returned from dlinfo if no error is
signaled. */
int result;
};
static void
dlinfo_doit (void *argsblock)
{
struct dlinfo_args *const args = argsblock;
struct link_map *l = args->handle;
switch (args->request)
{
case RTLD_DI_CONFIGADDR:
default:
args->result = -1;
_dl_signal_error (0, NULL, NULL, N_("unsupported dlinfo request"));
break;
case RTLD_DI_LMID:
*(Lmid_t *) args->arg = l->l_ns;
break;
case RTLD_DI_LINKMAP:
*(struct link_map **) args->arg = l;
break;
case RTLD_DI_SERINFO:
_dl_rtld_di_serinfo (l, args->arg, false);
break;
case RTLD_DI_SERINFOSIZE:
_dl_rtld_di_serinfo (l, args->arg, true);
break;
case RTLD_DI_ORIGIN:
strcpy (args->arg, l->l_origin);
break;
case RTLD_DI_TLS_MODID:
*(size_t *) args->arg = 0;
*(size_t *) args->arg = l->l_tls_modid;
break;
case RTLD_DI_TLS_DATA:
{
void *data = NULL;
if (l->l_tls_modid != 0)
data = GLRO(dl_tls_get_addr_soft) (l);
*(void **) args->arg = data;
break;
}
case RTLD_DI_PHDR:
*(const ElfW(Phdr) **) args->arg = l->l_phdr;
args->result = l->l_phnum;
break;
}
}
static int
dlinfo_implementation (void *handle, int request, void *arg)
{
struct dlinfo_args args = { handle, request, arg };
_dlerror_run (&dlinfo_doit, &args);
return args.result;
}
#ifdef SHARED
int
___dlinfo (void *handle, int request, void *arg)
{
if (GLRO (dl_dlfcn_hook) != NULL)
return GLRO (dl_dlfcn_hook)->dlinfo (handle, request, arg);
else
return dlinfo_implementation (handle, request, arg);
}
versioned_symbol (libc, ___dlinfo, dlinfo, GLIBC_2_34);
# if OTHER_SHLIB_COMPAT (libdl, GLIBC_2_3_3, GLIBC_2_34)
compat_symbol (libc, ___dlinfo, dlinfo, GLIBC_2_3_3);
# endif
#else /* !SHARED */
/* Also used with _dlfcn_hook. */
int
__dlinfo (void *handle, int request, void *arg)
{
return dlinfo_implementation (handle, request, arg);
}
weak_alias (__dlinfo, dlinfo)
#endif