1/*- 2 * Copyright (c) 2003 Jake Burkholder. 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/tstate.h> 36 37#include <errno.h> 38#include <stdarg.h> 39#include <stdlib.h> 40#include <unistd.h> 41 42__weak_reference(__makecontext, makecontext); 43 44void _ctx_done(ucontext_t *ucp); 45void _ctx_start(void); 46 47void 48__makecontext(ucontext_t *ucp, void (*start)(void), int argc, ...) 49{ 50 mcontext_t *mc; 51 uint64_t sp; 52 va_list ap; 53 int i; 54 55 mc = &ucp->uc_mcontext; 56 if (ucp == NULL || 57 (mc->_mc_flags & ((1L << _MC_VERSION_BITS) - 1)) != _MC_VERSION) 58 return; 59 if ((argc < 0) || (argc > 6) || 60 (ucp->uc_stack.ss_sp == NULL) || 61 (ucp->uc_stack.ss_size < MINSIGSTKSZ)) { 62 mc->_mc_flags = 0; 63 return; 64 } 65 mc = &ucp->uc_mcontext; 66 sp = (uint64_t)ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size; 67 va_start(ap, argc); 68 for (i = 0; i < argc; i++) 69 mc->mc_out[i] = va_arg(ap, uint64_t); 70 va_end(ap); 71 mc->mc_global[1] = (uint64_t)start; 72 mc->mc_global[2] = (uint64_t)ucp; 73 mc->mc_out[6] = sp - SPOFF - sizeof(struct frame); 74 mc->_mc_tnpc = (uint64_t)_ctx_start + 4; 75 mc->_mc_tpc = (uint64_t)_ctx_start; 76} 77 78void 79_ctx_done(ucontext_t *ucp) 80{ 81 82 if (ucp->uc_link == NULL) 83 exit(0); 84 else { 85 ucp->uc_mcontext._mc_flags = 0; 86 setcontext((const ucontext_t *)ucp->uc_link); 87 abort(); 88 } 89} 90