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
ctx_done(ucontext_t * ucp)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
__makecontext(ucontext_t * ucp,void (* func)(void),int argc,...)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