1 | /* Create new context for ARC. |
2 | Copyright (C) 2020-2024 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <sysdep.h> |
20 | #include <stdarg.h> |
21 | #include <stdint.h> |
22 | #include <sys/ucontext.h> |
23 | |
24 | void |
25 | __makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...) |
26 | { |
27 | extern void __startcontext (void) attribute_hidden; |
28 | unsigned long int sp, *r; |
29 | va_list vl; |
30 | int i, reg_args, stack_args; |
31 | |
32 | sp = ((unsigned long int) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size) & ~7; |
33 | |
34 | ucp->uc_mcontext.__sp = sp; |
35 | ucp->uc_mcontext.__fp = 0; |
36 | |
37 | /* __startcontext is sort of trampoline to invoke @func |
38 | From setcontext pov, the resume address is __startcontext, |
39 | set it up in BLINK place holder. */ |
40 | |
41 | ucp->uc_mcontext.__blink = (unsigned long int) &__startcontext; |
42 | |
43 | /* __startcontext passed 2 types of args |
44 | - args to @func setup in canonical r0-r7 |
45 | - @func and next function in r14,r15. */ |
46 | |
47 | ucp->uc_mcontext.__r14 = (unsigned long int) func; |
48 | ucp->uc_mcontext.__r15 = (unsigned long int) ucp->uc_link; |
49 | |
50 | r = &ucp->uc_mcontext.__r0; |
51 | |
52 | va_start (vl, argc); |
53 | |
54 | reg_args = argc > 8 ? 8 : argc; |
55 | for (i = 0; i < reg_args; i++) |
56 | *r-- = va_arg (vl, unsigned long int); |
57 | |
58 | stack_args = argc - reg_args; |
59 | |
60 | if (__glibc_unlikely (stack_args > 0)) |
61 | { |
62 | sp -= stack_args * sizeof (unsigned long int); |
63 | ucp->uc_mcontext.__sp = sp; |
64 | r = (unsigned long int *) sp; |
65 | |
66 | for (i = 0; i < stack_args; i++) |
67 | *r++ = va_arg (vl, unsigned long int); |
68 | } |
69 | |
70 | va_end (vl); |
71 | } |
72 | |
73 | weak_alias (__makecontext, makecontext) |
74 | |