1*249d5c7aSAndrew Turner /*-
2*249d5c7aSAndrew Turner * Copyright (c) 2015 The FreeBSD Foundation
3*249d5c7aSAndrew Turner *
4*249d5c7aSAndrew Turner * This software was developed by Andrew Turner under
5*249d5c7aSAndrew Turner * sponsorship from the FreeBSD Foundation.
6*249d5c7aSAndrew Turner *
7*249d5c7aSAndrew Turner * Redistribution and use in source and binary forms, with or without
8*249d5c7aSAndrew Turner * modification, are permitted provided that the following conditions
9*249d5c7aSAndrew Turner * are met:
10*249d5c7aSAndrew Turner * 1. Redistributions of source code must retain the above copyright
11*249d5c7aSAndrew Turner * notice, this list of conditions and the following disclaimer.
12*249d5c7aSAndrew Turner * 2. Redistributions in binary form must reproduce the above copyright
13*249d5c7aSAndrew Turner * notice, this list of conditions and the following disclaimer in the
14*249d5c7aSAndrew Turner * documentation and/or other materials provided with the distribution.
15*249d5c7aSAndrew Turner *
16*249d5c7aSAndrew Turner * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17*249d5c7aSAndrew Turner * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18*249d5c7aSAndrew Turner * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19*249d5c7aSAndrew Turner * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20*249d5c7aSAndrew Turner * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21*249d5c7aSAndrew Turner * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22*249d5c7aSAndrew Turner * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23*249d5c7aSAndrew Turner * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24*249d5c7aSAndrew Turner * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25*249d5c7aSAndrew Turner * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26*249d5c7aSAndrew Turner * SUCH DAMAGE.
27*249d5c7aSAndrew Turner */
28*249d5c7aSAndrew Turner
29*249d5c7aSAndrew Turner #include <sys/param.h>
30*249d5c7aSAndrew Turner
31*249d5c7aSAndrew Turner #include <machine/armreg.h>
32*249d5c7aSAndrew Turner
33*249d5c7aSAndrew Turner #include <inttypes.h>
34*249d5c7aSAndrew Turner #include <stdarg.h>
35*249d5c7aSAndrew Turner #include <stdlib.h>
36*249d5c7aSAndrew Turner #include <ucontext.h>
37*249d5c7aSAndrew Turner
38*249d5c7aSAndrew Turner void _ctx_start(void);
39*249d5c7aSAndrew Turner
40*249d5c7aSAndrew Turner void
ctx_done(ucontext_t * ucp)41*249d5c7aSAndrew Turner ctx_done(ucontext_t *ucp)
42*249d5c7aSAndrew Turner {
43*249d5c7aSAndrew Turner
44*249d5c7aSAndrew Turner if (ucp->uc_link == NULL) {
45*249d5c7aSAndrew Turner exit(0);
46*249d5c7aSAndrew Turner } else {
47*249d5c7aSAndrew Turner setcontext((const ucontext_t *)ucp->uc_link);
48*249d5c7aSAndrew Turner abort();
49*249d5c7aSAndrew Turner }
50*249d5c7aSAndrew Turner }
51*249d5c7aSAndrew Turner
52*249d5c7aSAndrew Turner __weak_reference(__makecontext, makecontext);
53*249d5c7aSAndrew Turner
54*249d5c7aSAndrew Turner void
__makecontext(ucontext_t * ucp,void (* func)(void),int argc,...)55*249d5c7aSAndrew Turner __makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
56*249d5c7aSAndrew Turner {
57*249d5c7aSAndrew Turner struct gpregs *gp;
58*249d5c7aSAndrew Turner va_list ap;
59*249d5c7aSAndrew Turner int i;
60*249d5c7aSAndrew Turner
61*249d5c7aSAndrew Turner /* A valid context is required. */
62*249d5c7aSAndrew Turner if (ucp == NULL)
63*249d5c7aSAndrew Turner return;
64*249d5c7aSAndrew Turner
65*249d5c7aSAndrew Turner if ((argc < 0) || (argc > 8))
66*249d5c7aSAndrew Turner return;
67*249d5c7aSAndrew Turner
68*249d5c7aSAndrew Turner gp = &ucp->uc_mcontext.mc_gpregs;
69*249d5c7aSAndrew Turner
70*249d5c7aSAndrew Turner va_start(ap, argc);
71*249d5c7aSAndrew Turner /* Pass up to eight arguments in x0-7. */
72*249d5c7aSAndrew Turner for (i = 0; i < argc && i < 8; i++)
73*249d5c7aSAndrew Turner gp->gp_x[i] = va_arg(ap, uint64_t);
74*249d5c7aSAndrew Turner va_end(ap);
75*249d5c7aSAndrew Turner
76*249d5c7aSAndrew Turner /* Set the stack */
77*249d5c7aSAndrew Turner gp->gp_sp = STACKALIGN(ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
78*249d5c7aSAndrew Turner /* Arrange for return via the trampoline code. */
79*249d5c7aSAndrew Turner gp->gp_elr = (__register_t)_ctx_start;
80*249d5c7aSAndrew Turner gp->gp_x[19] = (__register_t)func;
81*249d5c7aSAndrew Turner gp->gp_x[20] = (__register_t)ucp;
82*249d5c7aSAndrew Turner }
83