1 /* Copyright (C) 2001-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <ucontext.h>
19
20 extern int __getcontext (ucontext_t *ucp);
21 extern int __setcontext (const ucontext_t *ucp, int restoremask);
22
23 int
__swapcontext(ucontext_t * oucp,const ucontext_t * ucp)24 __swapcontext (ucontext_t *oucp, const ucontext_t *ucp)
25 {
26 extern void __swapcontext_ret (void);
27 /* Save the current machine context to oucp. */
28 __getcontext (oucp);
29 /* Modify oucp to skip the __setcontext call on reactivation. */
30 oucp->uc_mcontext.mc_gregs[MC_PC] = (long) __swapcontext_ret;
31 oucp->uc_mcontext.mc_gregs[MC_NPC] = ((long) __swapcontext_ret) + 4;
32 /* Restore the machine context in ucp. */
33 __setcontext (ucp, 1);
34 return 0;
35 }
36
37 asm (" \n\
38 .text \n\
39 .type __swapcontext_ret, #function \n\
40 __swapcontext_ret: \n\
41 return %i7 + 8 \n\
42 clr %o0 \n\
43 .size __swapcontext_ret, .-__swapcontext_ret \n\
44 ");
45
46 weak_alias (__swapcontext, swapcontext)
47