xref: /openbsd/lib/libc/thread/callbacks.c (revision 3cab2bb3)
1 /*
2  * Copyright (c) 2014 Philip Guenther <guenther@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <pthread.h>
18 #include <signal.h>
19 #include <stdio.h>
20 #include <string.h>
21 #include <unistd.h>
22 
23 #include "thread_private.h"
24 #include "rthread_cb.h"
25 
26 static __dead void
27 _thread_canceled(void)
28 {
29 	pthread_exit(PTHREAD_CANCELED);
30 }
31 
32 void
33 _thread_set_callbacks(const struct thread_callbacks *cb, size_t len)
34 {
35 	sigset_t allmask, omask;
36 
37 	if (sizeof(*cb) != len) {
38 		fprintf(stderr, "library mismatch: libc expected %zu but"
39 		    " libpthread gave %zu\n", sizeof(*cb), len);
40 		fflush(stderr);
41 		_exit(44);
42 	}
43 
44 	sigfillset(&allmask);
45 	if (sigprocmask(SIG_BLOCK, &allmask, &omask) == 0) {
46 		/* mprotect RW */
47 		memcpy(&_thread_cb, cb, sizeof(_thread_cb));
48 
49 		/*
50 		 * These are supplied by libc, but only enabled
51 		 * here when we actually need to prep for doing MT.
52 		 */
53 		_thread_cb.tc_canceled		= _thread_canceled;
54 		_thread_cb.tc_flockfile		= _thread_flockfile;
55 		_thread_cb.tc_ftrylockfile	= _thread_ftrylockfile;
56 		_thread_cb.tc_funlockfile	= _thread_funlockfile;
57 		_thread_cb.tc_malloc_lock	= _thread_malloc_lock;
58 		_thread_cb.tc_malloc_unlock	= _thread_malloc_unlock;
59 		_thread_cb.tc_atexit_lock	= _thread_atexit_lock;
60 		_thread_cb.tc_atexit_unlock	= _thread_atexit_unlock;
61 		_thread_cb.tc_atfork_lock	= _thread_atfork_lock;
62 		_thread_cb.tc_atfork_unlock	= _thread_atfork_unlock;
63 		_thread_cb.tc_arc4_lock		= _thread_arc4_lock;
64 		_thread_cb.tc_arc4_unlock	= _thread_arc4_unlock;
65 		_thread_cb.tc_mutex_lock	= _thread_mutex_lock;
66 		_thread_cb.tc_mutex_unlock	= _thread_mutex_unlock;
67 		_thread_cb.tc_mutex_destroy	= _thread_mutex_destroy;
68 		_thread_cb.tc_tag_lock		= _thread_tag_lock;
69 		_thread_cb.tc_tag_unlock	= _thread_tag_unlock;
70 		_thread_cb.tc_tag_storage	= _thread_tag_storage;
71 
72 		/* mprotect RO | LOCKPERM | NOUNMAP */
73 		sigprocmask(SIG_SETMASK, &omask, NULL);
74 	}
75 }
76