xref: /openbsd-src/lib/libc/thread/callbacks.c (revision 0b7734b3d77bb9b21afec6f4621cae6c805dbd45)
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 <stdio.h>
18 #include <signal.h>
19 #include <string.h>
20 #include <unistd.h>
21 #include "thread_private.h"
22 
23 void
24 _thread_set_callbacks(const struct thread_callbacks *cb, size_t len)
25 {
26 	sigset_t allmask, omask;
27 
28 	if (sizeof(*cb) != len) {
29 		fprintf(stderr, "library mismatch: libc expected %z but"
30 		    " libpthread gave %z\n", sizeof(*cb), len);
31 		fflush(stderr);
32 		_exit(44);
33 	}
34 
35 	sigfillset(&allmask);
36 	if (sigprocmask(SIG_BLOCK, &allmask, &omask) == 0) {
37 		/* mprotect RW */
38 		memcpy(&_thread_cb, cb, sizeof(_thread_cb));
39 		/* mprotect RO | LOCKPERM | NOUNMAP */
40 		sigprocmask(SIG_SETMASK, &omask, NULL);
41 	}
42 }
43