1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2004 Olivier Houchard 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/signal.h> 34 #include <sys/ucontext.h> 35 36 #include <machine/frame.h> 37 #include <machine/sigframe.h> 38 39 #include <errno.h> 40 #include <stdarg.h> 41 #include <stdlib.h> 42 #include <unistd.h> 43 #include <strings.h> 44 #include <signal.h> 45 46 __weak_reference(__signalcontext, signalcontext); 47 48 extern void _ctx_start(void); 49 50 int 51 __signalcontext(ucontext_t *ucp, int sig, __sighandler_t *func) 52 { 53 struct sigframe *sfp; 54 __greg_t *gr = ucp->uc_mcontext.__gregs; 55 unsigned int *sp; 56 57 sp = (unsigned int *)gr[_REG_SP]; 58 59 sfp = (struct sigframe *)sp - 1; 60 61 bzero(sfp, sizeof(*sfp)); 62 bcopy(ucp, &sfp->sf_uc, sizeof(*ucp)); 63 sfp->sf_si.si_signo = sig; 64 65 gr[_REG_SP] = (__greg_t)sfp; 66 /* Wipe out frame pointer. */ 67 gr[_REG_FP] = 0; 68 /* Arrange for return via the trampoline code. */ 69 gr[_REG_PC] = (__greg_t)_ctx_start; 70 gr[_REG_R4] = (__greg_t)func; 71 gr[_REG_R5] = (__greg_t)ucp; 72 gr[_REG_R0] = (__greg_t)sig; 73 gr[_REG_R1] = (__greg_t)&sfp->sf_si; 74 gr[_REG_R2] = (__greg_t)&sfp->sf_uc; 75 76 ucp->uc_link = &sfp->sf_uc; 77 sigdelset(&ucp->uc_sigmask, sig); 78 79 return (0); 80 } 81