freebsd-skq/lib/libc/include/nss_tls.h
Jacques Vidrine a03fd3b656 When a dynamic NSS module is built and linked against a thread
library, it may pull in that thread library at run time.  If the
process started out single-threaded, this could cause attempts to
release locks that do not exist.  Guard against this possibility by
checking __isthreaded before invoking thread primitives.

A similar problem remains if the process is linked against one thread
library, but the NSS module is linked against another.  This can only
be avoided by careful design of the NSS module.

Submitted by:	Sean McNeil <sean@mcneil.com> (mostly; bugs are mine)
2004-03-30 15:56:15 +00:00

81 lines
2.9 KiB
C

/*-
* Copyright (c) 2003 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by
* Jacques A. Vidrine, Safeport Network Services, and Network
* Associates Laboratories, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
* ("CBOSS"), as part of the DARPA CHATS research program.
*
* 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 AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*
* Macros which generate thread local storage handling code in NSS modules.
*/
#ifndef _NSS_TLS_H_
#define _NSS_TLS_H_
#define NSS_TLS_HANDLING(name) \
static pthread_key_t name##_state_key; \
static void name##_keyinit(void); \
static int name##_getstate(struct name##_state **); \
\
static void \
name##_keyinit(void) \
{ \
(void)_pthread_key_create(&name##_state_key, name##_endstate); \
} \
\
static int \
name##_getstate(struct name##_state **p) \
{ \
static struct name##_state st; \
static pthread_once_t keyinit = PTHREAD_ONCE_INIT; \
int rv; \
\
if (!__isthreaded || _pthread_main_np() != 0) { \
*p = &st; \
return (0); \
} \
rv = _pthread_once(&keyinit, name##_keyinit); \
if (rv != 0) \
return (rv); \
*p = _pthread_getspecific(name##_state_key); \
if (*p != NULL) \
return (0); \
*p = calloc(1, sizeof(**p)); \
if (*p == NULL) \
return (ENOMEM); \
rv = _pthread_setspecific(name##_state_key, *p); \
if (rv != 0) { \
free(*p); \
*p = NULL; \
} \
return (rv); \
} \
/* allow the macro invocation to end with a semicolon */ \
struct _clashproof_bmVjdGFy
#endif /* _NSS_TLS_H_ */