1 /*- 2 * Copyright (c) 2015 The FreeBSD Foundation 3 * All rights reserved. 4 * 5 * This software was developed by Andrew Turner under 6 * sponsorship from the FreeBSD Foundation. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 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. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 35 #include <machine/armreg.h> 36 37 #include <inttypes.h> 38 #include <stdarg.h> 39 #include <stdlib.h> 40 #include <ucontext.h> 41 42 void _ctx_start(void); 43 44 void 45 ctx_done(ucontext_t *ucp) 46 { 47 48 if (ucp->uc_link == NULL) { 49 exit(0); 50 } else { 51 setcontext((const ucontext_t *)ucp->uc_link); 52 abort(); 53 } 54 } 55 56 __weak_reference(__makecontext, makecontext); 57 58 void 59 __makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...) 60 { 61 struct gpregs *gp; 62 va_list ap; 63 int i; 64 65 /* A valid context is required. */ 66 if (ucp == NULL) 67 return; 68 69 if ((argc < 0) || (argc > 8)) 70 return; 71 72 gp = &ucp->uc_mcontext.mc_gpregs; 73 74 va_start(ap, argc); 75 /* Pass up to eight arguments in x0-7. */ 76 for (i = 0; i < argc && i < 8; i++) 77 gp->gp_x[i] = va_arg(ap, uint64_t); 78 va_end(ap); 79 80 /* Set the stack */ 81 gp->gp_sp = STACKALIGN(ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size); 82 /* Arrange for return via the trampoline code. */ 83 gp->gp_elr = (__register_t)_ctx_start; 84 gp->gp_x[19] = (__register_t)func; 85 gp->gp_x[20] = (__register_t)ucp; 86 } 87