2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2004 Marcel Moolenaar, Peter Grehan
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/ucontext.h>
38 typedef void (*handler_t)(uint32_t, uint32_t, uint32_t);
41 static void ctx_wrapper(ucontext_t *ucp, handler_t func, uint32_t sig,
42 uint32_t sig_si, uint32_t sig_uc);
44 __weak_reference(__signalcontext, signalcontext);
47 __signalcontext(ucontext_t *ucp, int sig, __sighandler_t *func)
53 /* Bail out if we don't have a valid ucontext pointer. */
58 * Build a 16-byte-aligned signal frame
60 sp = (ucp->uc_mcontext.mc_gpr[1] - 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;
69 * Subtract 48 bytes from stack to allow for frameptr
71 sp -= 6*sizeof(uint64_t);
75 * Setup the ucontext of the signal handler.
77 bzero(&ucp->uc_mcontext, sizeof(ucp->uc_mcontext));
78 ucp->uc_link = sig_uc;
79 sigdelset(&ucp->uc_sigmask, sig);
81 ucp->uc_mcontext.mc_vers = _MC_VERSION;
82 ucp->uc_mcontext.mc_len = sizeof(struct __mcontext);
83 ucp->uc_mcontext.mc_srr0 = (uint64_t) ctx_wrapper;
84 ucp->uc_mcontext.mc_gpr[1] = (uint64_t) sp;
85 ucp->uc_mcontext.mc_gpr[3] = (uint64_t) func;
86 ucp->uc_mcontext.mc_gpr[4] = (uint64_t) sig;
87 ucp->uc_mcontext.mc_gpr[5] = (uint64_t) sig_si;
88 ucp->uc_mcontext.mc_gpr[6] = (uint64_t) sig_uc;
94 ctx_wrapper(ucontext_t *ucp, handler_t func, uint32_t sig, uint32_t sig_si,
98 (*func)(sig, sig_si, sig_uc);
99 if (ucp->uc_link == NULL)
101 setcontext((const ucontext_t *)ucp->uc_link);
102 /* should never get here */