1 /*- 2 * Copyright (c) 2015 The FreeBSD Foundation 3 * 4 * This software was developed by Andrew Turner under 5 * sponsorship from the FreeBSD Foundation. 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 #include <sys/param.h> 31 32 #include <machine/armreg.h> 33 34 #include <inttypes.h> 35 #include <stdarg.h> 36 #include <stdlib.h> 37 #include <ucontext.h> 38 39 void _ctx_start(void); 40 41 void 42 ctx_done(ucontext_t *ucp) 43 { 44 45 if (ucp->uc_link == NULL) { 46 exit(0); 47 } else { 48 setcontext((const ucontext_t *)ucp->uc_link); 49 abort(); 50 } 51 } 52 53 __weak_reference(__makecontext, makecontext); 54 55 void 56 __makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...) 57 { 58 struct gpregs *gp; 59 va_list ap; 60 int i; 61 62 /* A valid context is required. */ 63 if (ucp == NULL) 64 return; 65 66 if ((argc < 0) || (argc > 8)) 67 return; 68 69 gp = &ucp->uc_mcontext.mc_gpregs; 70 71 va_start(ap, argc); 72 /* Pass up to eight arguments in x0-7. */ 73 for (i = 0; i < argc && i < 8; i++) 74 gp->gp_x[i] = va_arg(ap, uint64_t); 75 va_end(ap); 76 77 /* Set the stack */ 78 gp->gp_sp = STACKALIGN(ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size); 79 /* Arrange for return via the trampoline code. */ 80 gp->gp_elr = (__register_t)_ctx_start; 81 gp->gp_x[19] = (__register_t)func; 82 gp->gp_x[20] = (__register_t)ucp; 83 } 84