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/param.h>
30
31 #include <machine/armreg.h>
32
33 #include <inttypes.h>
34 #include <stdarg.h>
35 #include <stdlib.h>
36 #include <ucontext.h>
37
38 void _ctx_start(void);
39
40 void
ctx_done(ucontext_t * ucp)41 ctx_done(ucontext_t *ucp)
42 {
43
44 if (ucp->uc_link == NULL) {
45 exit(0);
46 } else {
47 setcontext((const ucontext_t *)ucp->uc_link);
48 abort();
49 }
50 }
51
52 __weak_reference(__makecontext, makecontext);
53
54 void
__makecontext(ucontext_t * ucp,void (* func)(void),int argc,...)55 __makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
56 {
57 struct gpregs *gp;
58 va_list ap;
59 int i;
60
61 /* A valid context is required. */
62 if (ucp == NULL)
63 return;
64
65 if ((argc < 0) || (argc > 8))
66 return;
67
68 gp = &ucp->uc_mcontext.mc_gpregs;
69
70 va_start(ap, argc);
71 /* Pass up to eight arguments in x0-7. */
72 for (i = 0; i < argc && i < 8; i++)
73 gp->gp_x[i] = va_arg(ap, uint64_t);
74 va_end(ap);
75
76 /* Set the stack */
77 gp->gp_sp = STACKALIGN(ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
78 /* Arrange for return via the trampoline code. */
79 gp->gp_elr = (__register_t)_ctx_start;
80 gp->gp_x[19] = (__register_t)func;
81 gp->gp_x[20] = (__register_t)ucp;
82 }
83