1 /*- 2 * Copyright (c) 2004 Olivier Houchard 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 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/signal.h> 32 #include <sys/ucontext.h> 33 34 #include <machine/frame.h> 35 #include <machine/sigframe.h> 36 37 #include <errno.h> 38 #include <stdarg.h> 39 #include <stdlib.h> 40 #include <unistd.h> 41 #include <strings.h> 42 #include <signal.h> 43 44 __weak_reference(__signalcontext, signalcontext); 45 46 extern void _ctx_start(void); 47 48 int 49 __signalcontext(ucontext_t *ucp, int sig, __sighandler_t *func) 50 { 51 struct sigframe *sfp; 52 __greg_t *gr = ucp->uc_mcontext.__gregs; 53 unsigned int *sp; 54 mcontext_t *mc; 55 56 mc = &ucp->uc_mcontext; 57 sp = (unsigned int *) 58 (((uintptr_t)ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size) & ~7); 59 60 sfp = (struct sigframe *)sp - 1; 61 62 bzero(sfp, sizeof(*sfp)); 63 bcopy(ucp, &sfp->sf_uc, sizeof(*ucp)); 64 sfp->sf_si.si_signo = sig; 65 66 gr[_REG_SP] = (__greg_t)sp; 67 /* Wipe out frame pointer. */ 68 gr[_REG_FP] = 0; 69 /* Arrange for return via the trampoline code. */ 70 gr[_REG_LR] = (__greg_t)_ctx_start; 71 gr[_REG_PC] = (__greg_t)func; 72 gr[_REG_R0] = (__greg_t)ucp; 73 74 ucp->uc_link = &sfp->sf_uc; 75 sigdelset(&ucp->uc_sigmask, sig); 76 77 return (0); 78 } 79