1 /* Save current context.
3 Copyright (C) 2009-2020 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 <https://www.gnu.org/licenses/>. */
22 #include "ucontext_i.h"
23 #include "ucontext-internal.h"
25 /* int getcontext (ucontext_t *ucp)
27 Returns 0 on success -1 and errno on failure.
34 /* The saved context will return to the getcontext() call point
35 with a return value of 0 */
36 str xzr, [x0, oX0 + 0 * SZREG]
38 stp x18, x19, [x0, oX0 + 18 * SZREG]
39 stp x20, x21, [x0, oX0 + 20 * SZREG]
40 stp x22, x23, [x0, oX0 + 22 * SZREG]
41 stp x24, x25, [x0, oX0 + 24 * SZREG]
42 stp x26, x27, [x0, oX0 + 26 * SZREG]
43 stp x28, x29, [x0, oX0 + 28 * SZREG]
44 str x30, [x0, oX0 + 30 * SZREG]
46 /* Place LR into the saved PC, this will ensure that when
47 switching to this saved context with setcontext() control
48 will pass back to the caller of getcontext(), we have
49 already arrange to return the appropriate return value in x0
53 /* Save the current SP */
57 /* Initialize the pstate. */
58 str xzr, [x0, oPSTATE]
60 /* Figure out where to place the first context extension
62 add x2, x0, #oEXTENSION
64 /* Write the context extension fpsimd header. */
65 mov w3, #(FPSIMD_MAGIC & 0xffff)
66 movk w3, #(FPSIMD_MAGIC >> 16), lsl #16
67 str w3, [x2, #oHEAD + oMAGIC]
68 mov w3, #FPSIMD_CONTEXT_SIZE
69 str w3, [x2, #oHEAD + oSIZE]
71 /* Fill in the FP SIMD context. */
72 add x3, x2, #oV0 + 8 * SZVREG
73 stp q8, q9, [x3], # 2 * SZVREG
74 stp q10, q11, [x3], # 2 * SZVREG
75 stp q12, q13, [x3], # 2 * SZVREG
76 stp q14, q15, [x3], # 2 * SZVREG
84 str w4, [x3, oFPCR - oFPSR]
86 /* Write the termination context extension header. */
87 add x2, x2, #FPSIMD_CONTEXT_SIZE
89 str xzr, [x2, #oHEAD + oMAGIC]
90 str xzr, [x2, #oHEAD + oSIZE]
92 /* Grab the signal mask */
93 /* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */
94 add PTR_REG (2), PTR_REG (0), #UCONTEXT_SIGMASK
98 mov x8, SYS_ify (rt_sigprocmask)
102 /* Return 0 for success */
106 b C_SYMBOL_NAME(__syscall_error)
108 PSEUDO_END (__getcontext)
109 weak_alias (__getcontext, getcontext)