1/* Swap two contexts. OpenRISC version.
2 Copyright (C) 2022-2024 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 "ucontext_i.h"
21
22/* int swapcontext (ucontext_t *oucp, const ucontext_t *ucp) */
23 .text
24ENTRY(__swapcontext)
25
26 /* Same as getcontext. */
27 /* Store r1, the stack pointer. */
28 l.sw (UCONTEXT_MCONTEXT + 1*4)(r3), r1
29 /* Store r2, the frame pointer. */
30 l.sw (UCONTEXT_MCONTEXT + 2*4)(r3), r2
31 /* Store r9, the link register. */
32 l.sw (UCONTEXT_MCONTEXT + 9*4)(r3), r9
33 /* Store r9 to reg[11] too, as we need two links for makecontext. */
34 l.sw (UCONTEXT_MCONTEXT + 11*4)(r3), r9
35 /* Store r10, the TLS register. */
36 l.sw (UCONTEXT_MCONTEXT + 10*4)(r3), r10
37 /* Store r14-r30 even, callee saved registers. */
38 l.sw (UCONTEXT_MCONTEXT + 14*4)(r3), r14
39 l.sw (UCONTEXT_MCONTEXT + 16*4)(r3), r16
40 l.sw (UCONTEXT_MCONTEXT + 18*4)(r3), r18
41 l.sw (UCONTEXT_MCONTEXT + 20*4)(r3), r20
42 l.sw (UCONTEXT_MCONTEXT + 22*4)(r3), r22
43 l.sw (UCONTEXT_MCONTEXT + 24*4)(r3), r24
44 l.sw (UCONTEXT_MCONTEXT + 26*4)(r3), r26
45 l.sw (UCONTEXT_MCONTEXT + 28*4)(r3), r28
46 l.sw (UCONTEXT_MCONTEXT + 30*4)(r3), r30
47
48 /* Store ucp to non-argument syscall preserved register. */
49 l.ori r30, r4, 0
50
51 /* Get signal mask. */
52 /* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */
53 l.ori r6, r0, _NSIG8
54 l.addi r5, r3, UCONTEXT_SIGMASK
55 l.ori r4, r0, 0
56 l.ori r3, r0, SIG_BLOCK
57 l.ori r11, r0, SYS_ify (rt_sigprocmask)
58 /* Do the syscall. */
59 l.sys 1
60 l.nop
61
62 /* if -4096 < ret < 0 holds, it's an error */
63 l.sfgeui r11, 0xf001
64 l.bf 1f
65 l.nop
66
67 /* Same as setcontext. */
68
69 /* Restore signal mask. */
70 /* rt_sigprocmask (SIG_SETMASK, &ucp->uc_sigmask, NULL, _NSIG8) */
71 l.ori r6, r0, _NSIG8
72 l.ori r5, r0, 0
73 l.addi r4, r30, UCONTEXT_SIGMASK
74 l.ori r3, r0, SIG_SETMASK
75 l.ori r11, r0, SYS_ify (rt_sigprocmask)
76 /* Do the syscall. */
77 l.sys 1
78 l.nop
79
80 /* if -4096 < ret < 0 holds, it's an error */
81 l.sfgeui r11, 0xf001
82 l.bf 1f
83 l.nop
84
85 /* Restore argument registers, for the makecontext case. */
86 l.lwz r3, (UCONTEXT_MCONTEXT + 3*4)(r30)
87 l.lwz r4, (UCONTEXT_MCONTEXT + 4*4)(r30)
88 l.lwz r5, (UCONTEXT_MCONTEXT + 5*4)(r30)
89 l.lwz r6, (UCONTEXT_MCONTEXT + 6*4)(r30)
90 l.lwz r7, (UCONTEXT_MCONTEXT + 7*4)(r30)
91 l.lwz r8, (UCONTEXT_MCONTEXT + 8*4)(r30)
92
93 /* Restore registers stored in getcontext. */
94 l.lwz r1, (UCONTEXT_MCONTEXT + 1*4)(r30)
95 l.lwz r2, (UCONTEXT_MCONTEXT + 2*4)(r30)
96 l.lwz r9, (UCONTEXT_MCONTEXT + 9*4)(r30)
97 l.lwz r10, (UCONTEXT_MCONTEXT + 10*4)(r30)
98 l.lwz r11, (UCONTEXT_MCONTEXT + 11*4)(r30)
99 l.lwz r14, (UCONTEXT_MCONTEXT + 14*4)(r30)
100 l.lwz r16, (UCONTEXT_MCONTEXT + 16*4)(r30)
101 l.lwz r18, (UCONTEXT_MCONTEXT + 18*4)(r30)
102 l.lwz r20, (UCONTEXT_MCONTEXT + 20*4)(r30)
103 l.lwz r22, (UCONTEXT_MCONTEXT + 22*4)(r30)
104 l.lwz r24, (UCONTEXT_MCONTEXT + 24*4)(r30)
105 l.lwz r26, (UCONTEXT_MCONTEXT + 26*4)(r30)
106 l.lwz r28, (UCONTEXT_MCONTEXT + 28*4)(r30)
107 l.lwz r30, (UCONTEXT_MCONTEXT + 30*4)(r30)
108
109 l.jr r11
110 l.ori r11, r0, 0
111
1121: l.j __syscall_error
113 l.ori r3, r11, 0
114
115END (__swapcontext)
116weak_alias (__swapcontext, swapcontext)
117

source code of glibc/sysdeps/unix/sysv/linux/or1k/swapcontext.S