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glibc/dlfcn/bug-dl-leaf-lib.c
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/* Make sure dlopen/dlclose are not marked as leaf functions. | |
Copyright (C) 2013-2016 Free Software Foundation, Inc. | |
This file is part of the GNU C Library. | |
Contributed by Mike Frysinger <vapier@gentoo.org> | |
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 | |
<http://www.gnu.org/licenses/>. */ | |
/* The bug-dl-leaf.c file will call our lib_main directly. We do this to | |
keep things simple -- no need to use --export-dynamic with the linker | |
or build the main ELF as a PIE. | |
The lib_main func will modify some of its state while dlopening and | |
dlclosing the bug-dl-leaf-lib-cb.so library. The constructors and | |
destructors in that library will call back into this library to also | |
muck with state (the check_val_xxx funcs). | |
If dlclose/dlopen are marked as "leaf" functions, then with newer | |
versions of gcc, the state modification won't work correctly. */ | |
#include <assert.h> | |
#include <dlfcn.h> | |
static int val = 1; | |
static int called = 0; | |
void check_val_init (void) | |
{ | |
called = 1; | |
assert (val == 2); | |
} | |
void check_val_fini (void) | |
{ | |
called = 2; | |
assert (val == 4); | |
} | |
int lib_main (void) | |
{ | |
int ret __attribute__ ((unused)); | |
void *hdl; | |
/* Make sure the constructor sees the updated val. */ | |
val = 2; | |
hdl = dlopen ("bug-dl-leaf-lib-cb.so", RTLD_GLOBAL | RTLD_LAZY); | |
val = 3; | |
assert (hdl); | |
assert (called == 1); | |
/* Make sure the destructor sees the updated val. */ | |
val = 4; | |
ret = dlclose (hdl); | |
val = 5; | |
assert (ret == 0); | |
assert (called == 2); | |
return !val; | |
} |