add header glue
[dragonfly.git] / lib / libc / amd64 / gen / signalcontext.c
CommitLineData
17030342
MD
1/*
2 * Copyright (c) 2003 Marcel Moolenaar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 * $FreeBSD: src/lib/libc/amd64/gen/signalcontext.c,v 1.2 2003/07/26 12:58:28 davidxu Exp $
27 * $DragonFly: src/lib/libc/amd64/gen/Attic/signalcontext.c,v 1.1 2004/02/02 05:43:14 dillon Exp $
28 */
29
30#include <sys/types.h>
31#include <sys/ucontext.h>
32#include <signal.h>
33#include <stdlib.h>
34#include <strings.h>
35
36typedef void (*handler_t)(uint64_t, uint64_t, uint64_t);
37
38/* Prototypes */
39static void ctx_wrapper(ucontext_t *ucp, handler_t func, uint64_t *args);
40
41__weak_reference(__signalcontext, signalcontext);
42
43int
44__signalcontext(ucontext_t *ucp, int sig, __sighandler_t *func)
45{
46 uint64_t *args;
47 siginfo_t *sig_si;
48 ucontext_t *sig_uc;
49 uint64_t sp;
50
51 /* Bail out if we don't have a valid ucontext pointer. */
52 if (ucp == NULL)
53 abort();
54
55 /*
56 * Build a signal frame and copy the arguments of signal handler
57 * 'func' onto the stack. We only need 3 arguments, but we
58 * create room for 4 so that we are 16-byte aligned.
59 */
60 sp = (ucp->uc_mcontext.mc_rsp - sizeof(ucontext_t)) & ~15UL;
61 sig_uc = (ucontext_t *)sp;
62 bcopy(ucp, sig_uc, sizeof(*sig_uc));
63 sp = (sp - sizeof(siginfo_t)) & ~15UL;
64 sig_si = (siginfo_t *)sp;
65 bzero(sig_si, sizeof(*sig_si));
66 sig_si->si_signo = sig;
67 sp -= 4 * sizeof(uint64_t);
68 args = (uint64_t *)sp;
69 args[0] = sig;
70 args[1] = (intptr_t)sig_si;
71 args[2] = (intptr_t)sig_uc;
72 args[3] = 0;
73 sp -= 16;
74
75 /*
76 * Setup the ucontext of the signal handler.
77 */
78 bzero(&ucp->uc_mcontext, sizeof(ucp->uc_mcontext));
79 ucp->uc_link = sig_uc;
80 sigdelset(&ucp->uc_sigmask, sig);
81
82 ucp->uc_mcontext.mc_len = sizeof(mcontext_t);
83 ucp->uc_mcontext.mc_rdi = (register_t)ucp;
84 ucp->uc_mcontext.mc_rsi = (register_t)func;
85 ucp->uc_mcontext.mc_rdx = (register_t)args;
86 ucp->uc_mcontext.mc_rbp = (register_t)sp;
87 ucp->uc_mcontext.mc_rbx = (register_t)sp;
88 ucp->uc_mcontext.mc_rsp = (register_t)sp;
89 ucp->uc_mcontext.mc_rip = (register_t)ctx_wrapper;
90 return (0);
91}
92
93static void
94ctx_wrapper(ucontext_t *ucp, handler_t func, uint64_t *args)
95{
96
97 (*func)(args[0], args[1], args[2]);
98 if (ucp->uc_link == NULL)
99 exit(0);
100 setcontext((const ucontext_t *)ucp->uc_link);
101 /* should never get here */
102 abort();
103 /* NOTREACHED */
104}