/*      $NetBSD: initfini.c,v 1.17 2024/01/20 14:52:48 christos Exp $    */

/*-
* Copyright (c) 2007 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Doran.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

#include <sys/cdefs.h>
__RCSID("$NetBSD: initfini.c,v 1.17 2024/01/20 14:52:48 christos Exp $");

#ifdef _LIBC
#include "namespace.h"
#endif

#include <sys/param.h>
#include <sys/exec.h>
#include <sys/tls.h>
#include <stdbool.h>
#include "extern.h"
#include "csu-common.h"

void    __guard_setup(void);
void    __libc_thr_init(void);
void    __libc_atexit_init(void);
void    __libc_env_init(void);

#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
__dso_hidden void       __libc_static_tls_setup(void);
#endif

#ifdef __weak_alias
__weak_alias(_dlauxinfo,___dlauxinfo)
static void *__libc_dlauxinfo;

void *___dlauxinfo(void) __pure;
__weakref_visible void * real_dlauxinfo(void) __weak_reference(_dlauxinfo);

void *
___dlauxinfo(void)
{
       return __libc_dlauxinfo;
}
#endif

static bool libc_initialised;

/*
* Declare as common symbol to allow new libc with older binaries to
* not trigger an undefined reference.
*/
struct ps_strings *__ps_strings __common;
char *__progname __common;
char **environ __common;

/*
* _libc_init is called twice.  One call comes explicitly from crt0.o
* (for newer versions) and the other is via global constructor handling.
*
* In static binaries the explicit call is first; in dynamically linked
* binaries the global constructors of libc are called from ld.elf_so
* before crt0.o is reached.
*
* Note that __ps_strings is set by crt0.o. So in the dynamic case, it
* hasn't been set yet when we get here, and __libc_dlauxinfo is not
* (ever) assigned. But this is ok because __libc_dlauxinfo is only
* used in static binaries, because it's there to substitute for the
* dynamic linker. In static binaries __ps_strings will have been set
* up when we get here and we get a valid __libc_dlauxinfo.
*
* This code causes problems for Emacs because Emacs's undump
* mechanism saves the __ps_strings value from the startup execution;
* then running the resulting binary it gets here before crt0 has
* assigned the current execution's value to __ps_strings, and in an
* environment with ASLR this can cause the assignment of
* __libc_dlauxinfo to receive SIGSEGV.
*/
void __section(".text.startup")
_libc_init(void)
{

       if (libc_initialised)
               return;

       libc_initialised = 1;

       /* Only initialize _dlauxinfo for static binaries. */
       if (__ps_strings != NULL && real_dlauxinfo == ___dlauxinfo)
               __libc_dlauxinfo = __ps_strings->ps_argvstr +
                   __ps_strings->ps_nargvstr + __ps_strings->ps_nenvstr + 2;

       /* For -fstack-protector */
       __guard_setup();

       /* Atomic operations */
       __libc_atomic_init();

#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
       /* Initialize TLS for statically linked programs. */
       __libc_static_tls_setup();
#endif

       /* Threads */
       __libc_thr_init();

       /* Initialize the atexit mutexes */
       __libc_atexit_init();
}