1 | /* Modify saved context. |
2 | Copyright (C) 2015-2022 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 |
24 | ENTRY(__swapcontext) |
25 | |
26 | /* Same as getcontext(). */ |
27 | stw r16, (UCONTEXT_MCONTEXT + 16*4)(r4) |
28 | stw r17, (UCONTEXT_MCONTEXT + 17*4)(r4) |
29 | stw r18, (UCONTEXT_MCONTEXT + 18*4)(r4) |
30 | stw r19, (UCONTEXT_MCONTEXT + 19*4)(r4) |
31 | stw r20, (UCONTEXT_MCONTEXT + 20*4)(r4) |
32 | stw r21, (UCONTEXT_MCONTEXT + 21*4)(r4) |
33 | stw r22, (UCONTEXT_MCONTEXT + 22*4)(r4) |
34 | stw ra, (UCONTEXT_MCONTEXT + 24*4)(r4) |
35 | stw fp, (UCONTEXT_MCONTEXT + 25*4)(r4) |
36 | stw gp, (UCONTEXT_MCONTEXT + 26*4)(r4) |
37 | /* Store return address at place for EA. */ |
38 | stw ra, (UCONTEXT_MCONTEXT + 28*4)(r4) |
39 | stw sp, (UCONTEXT_MCONTEXT + 29*4)(r4) |
40 | /* Store zero for return success. */ |
41 | stw zero, (UCONTEXT_MCONTEXT + 2*4)(r4) |
42 | |
43 | /* Store value "1" at uc_flags to recognize as getcontext created. */ |
44 | movi r2, 1 |
45 | stw r2, UCONTEXT_FLAGS(r4) |
46 | |
47 | /* Store MCONTEXT_VERSION at first word of mcontext_t. */ |
48 | movi r2, MCONTEXT_VERSION |
49 | stw r2, UCONTEXT_MCONTEXT(r4) |
50 | |
51 | /* Save ucp to non-argument syscall preserved register. */ |
52 | mov r10, r5 |
53 | |
54 | /* Get signal mask. */ |
55 | /* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */ |
56 | movi r7, _NSIG8 |
57 | addi r6, r4, UCONTEXT_SIGMASK |
58 | mov r5, zero |
59 | movi r4, SIG_BLOCK |
60 | movi r2, SYS_ify (rt_sigprocmask) |
61 | trap |
62 | bne r7, zero, SYSCALL_ERROR_LABEL |
63 | |
64 | |
65 | /* Same as setcontext(). */ |
66 | ldw r5, UCONTEXT_FLAGS(r10) |
67 | movi r6, 1 |
68 | bne r5, r6, .Lsigreturn |
69 | |
70 | /* Restore signal mask. */ |
71 | /* rt_sigprocmask (SIG_SETMASK, &ucp->uc_sigmask, NULL, _NSIG8) */ |
72 | movi r7, _NSIG8 |
73 | addi r5, r10, UCONTEXT_SIGMASK |
74 | mov r6, zero |
75 | movi r4, SIG_SETMASK |
76 | movi r2, SYS_ify (rt_sigprocmask) |
77 | trap |
78 | bne r7, zero, SYSCALL_ERROR_LABEL |
79 | |
80 | /* Restore argument registers, for the makecontext() case. */ |
81 | ldw r4, (UCONTEXT_MCONTEXT + 4*4)(r10) |
82 | ldw r5, (UCONTEXT_MCONTEXT + 5*4)(r10) |
83 | ldw r6, (UCONTEXT_MCONTEXT + 6*4)(r10) |
84 | ldw r7, (UCONTEXT_MCONTEXT + 7*4)(r10) |
85 | |
86 | ldw r16, (UCONTEXT_MCONTEXT + 16*4)(r10) |
87 | ldw r17, (UCONTEXT_MCONTEXT + 17*4)(r10) |
88 | ldw r18, (UCONTEXT_MCONTEXT + 18*4)(r10) |
89 | ldw r19, (UCONTEXT_MCONTEXT + 19*4)(r10) |
90 | ldw r20, (UCONTEXT_MCONTEXT + 20*4)(r10) |
91 | ldw r21, (UCONTEXT_MCONTEXT + 21*4)(r10) |
92 | ldw r22, (UCONTEXT_MCONTEXT + 22*4)(r10) |
93 | ldw ra, (UCONTEXT_MCONTEXT + 24*4)(r10) |
94 | ldw fp, (UCONTEXT_MCONTEXT + 25*4)(r10) |
95 | ldw gp, (UCONTEXT_MCONTEXT + 26*4)(r10) |
96 | /* Load address to continue execution. */ |
97 | ldw r3, (UCONTEXT_MCONTEXT + 28*4)(r10) |
98 | ldw sp, (UCONTEXT_MCONTEXT + 29*4)(r10) |
99 | |
100 | mov r2, zero |
101 | jmp r3 |
102 | |
103 | .Lsigreturn: |
104 | addi sp, sp, -RT_SIGFRAME_SIZE |
105 | cfi_adjust_cfa_offset (RT_SIGFRAME_SIZE) |
106 | |
107 | addi r2, sp, RT_SIGFRAME_UCONTEXT |
108 | movi r3, UCONTEXT_SIZE-4 |
109 | 1: |
110 | add r6, r4, r3 |
111 | ldw r5, 0(r6) |
112 | add r7, r2, r3 |
113 | addi r3, r3, -4 |
114 | stw r5, 0(r7) |
115 | bgt r3, zero, 1b |
116 | |
117 | movi r2, SYS_ify (rt_sigreturn) |
118 | trap |
119 | |
120 | addi sp, sp, RT_SIGFRAME_SIZE |
121 | cfi_adjust_cfa_offset (-RT_SIGFRAME_SIZE) |
122 | br SYSCALL_ERROR_LABEL |
123 | |
124 | PSEUDO_END (__swapcontext) |
125 | weak_alias (__swapcontext, swapcontext) |
126 | |