1 /* Set current context.
3 Copyright (C) 2009-2015 Free Software Foundation, Inc.
5 This file is part of the GNU C Library.
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Lesser General Public License as
9 published by the Free Software Foundation; either version 2.1 of the
10 License, or (at your option) any later version.
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
17 You should have received a copy of the GNU Lesser General Public
18 License along with the GNU C Library; if not, see
19 <http://www.gnu.org/licenses/>. */
22 #include "ucontext_i.h"
23 #include "ucontext-internal.h"
25 /* int __setcontext (const ucontext_t *ucp)
27 Restores the machine context in UCP and thereby resumes execution
30 This implementation is intended to be used for *synchronous* context
31 switches only. Therefore, it does not have to restore anything
32 other than the PRESERVED state. */
37 /* Save a copy of UCP. */
40 /* Set the signal mask with
41 rt_sigprocmask (SIG_SETMASK, mask, NULL, _NSIG/8). */
43 add x1, x9, #UCONTEXT_SIGMASK
46 mov x8, SYS_ify (rt_sigprocmask)
49 b C_SYMBOL_NAME (__syscall_error)
51 /* Restore the general purpose registers. */
54 cfi_offset (x18, oX0 + 18 * SZREG)
55 cfi_offset (x19, oX0 + 19 * SZREG)
56 cfi_offset (x20, oX0 + 20 * SZREG)
57 cfi_offset (x21, oX0 + 21 * SZREG)
58 cfi_offset (x22, oX0 + 22 * SZREG)
59 cfi_offset (x23, oX0 + 23 * SZREG)
60 cfi_offset (x24, oX0 + 24 * SZREG)
61 cfi_offset (x25, oX0 + 25 * SZREG)
62 cfi_offset (x26, oX0 + 26 * SZREG)
63 cfi_offset (x27, oX0 + 27 * SZREG)
64 cfi_offset (x28, oX0 + 28 * SZREG)
65 cfi_offset (x29, oX0 + 29 * SZREG)
66 cfi_offset (x30, oX0 + 30 * SZREG)
68 cfi_offset ( d8, oV0 + 8 * SZVREG)
69 cfi_offset ( d9, oV0 + 9 * SZVREG)
70 cfi_offset (d10, oV0 + 10 * SZVREG)
71 cfi_offset (d11, oV0 + 11 * SZVREG)
72 cfi_offset (d12, oV0 + 12 * SZVREG)
73 cfi_offset (d13, oV0 + 13 * SZVREG)
74 cfi_offset (d14, oV0 + 14 * SZVREG)
75 cfi_offset (d15, oV0 + 15 * SZVREG)
76 ldp x18, x19, [x0, oX0 + 18 * SZREG]
77 ldp x20, x21, [x0, oX0 + 20 * SZREG]
78 ldp x22, x23, [x0, oX0 + 22 * SZREG]
79 ldp x24, x25, [x0, oX0 + 24 * SZREG]
80 ldp x26, x27, [x0, oX0 + 26 * SZREG]
81 ldp x28, x29, [x0, oX0 + 28 * SZREG]
82 ldr x30, [x0, oX0 + 30 * SZREG]
86 /* Check for FP SIMD context. We don't support restoring
87 contexts created by the kernel, so this context must have
88 been created by getcontext. Hence we can rely on the
89 first extension block being the FP SIMD context. */
90 add x2, x0, #oEXTENSION
92 mov w3, #(FPSIMD_MAGIC & 0xffff)
93 movk w3, #(FPSIMD_MAGIC >> 16), lsl #16
94 ldr w1, [x2, #oHEAD + oMAGIC]
98 /* Restore the FP SIMD context. */
99 add x3, x2, #oV0 + 8 * SZVREG
100 ldp d8, d9, [x3], #2 * SZVREG
101 ldp d10, d11, [x3], #2 * SZVREG
102 ldp d12, d13, [x3], #2 * SZVREG
103 ldp d14, d15, [x3], #2 * SZVREG
110 ldr w4, [x3, oFPCR - oFPSR]
115 /* Restore arg registers. */
116 ldp x2, x3, [x0, oX0 + 2 * SZREG]
117 ldp x4, x5, [x0, oX0 + 4 * SZREG]
118 ldp x6, x7, [x0, oX0 + 6 * SZREG]
119 ldp x0, x1, [x0, oX0 + 0 * SZREG]
120 /* Jump to the new pc value. */
122 PSEUDO_END (__setcontext)
123 weak_alias (__setcontext, setcontext)
125 ENTRY (__startcontext)
127 cbnz x0, __setcontext
128 1: b HIDDEN_JUMPTARGET (_exit)