1 /* Modify saved context.
3 Copyright (C) 2009-2023 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/>. */
23 #include "ucontext_i.h"
24 #include "ucontext-internal.h"
26 /* int swapcontext (ucontext_t *oucp, const ucontext_t *ucp) */
31 /* Set the value returned when swapcontext() returns in this context.
32 And set up x1 to become the return address of the caller, so we
33 can return there with a normal RET instead of an indirect jump. */
34 stp xzr, x30, [x0, oX0 + 0 * SZREG]
35 /* Arrange the oucp context to return to 2f. */
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]
49 /* Figure out where to place the first context extension
51 add x2, x0, #oEXTENSION
53 /* Write the context extension fpsimd header. */
54 mov w3, #(FPSIMD_MAGIC & 0xffff)
55 movk w3, #(FPSIMD_MAGIC >> 16), lsl #16
56 str w3, [x2, #oHEAD + oMAGIC]
57 mov w3, #FPSIMD_CONTEXT_SIZE
58 str w3, [x2, #oHEAD + oSIZE]
60 /* Fill in the FP SIMD context. */
61 add x3, x2, #oV0 + 8 * SZVREG
62 stp q8, q9, [x3], #2 * SZVREG
63 stp q10, q11, [x3], #2 * SZVREG
64 stp q12, q13, [x3], #2 * SZVREG
65 stp q14, q15, [x3], #2 * SZVREG
70 str w4, [x3, #oFPSR - oFPSR]
73 str w4, [x3, #oFPCR - oFPSR]
75 /* Write the termination context extension header. */
76 add x2, x2, #FPSIMD_CONTEXT_SIZE
78 str wzr, [x2, #oHEAD + oMAGIC]
79 str wzr, [x2, #oHEAD + oSIZE]
84 /* rt_sigprocmask (SIG_SETMASK, &ucp->uc_sigmask, &oucp->uc_sigmask,
86 /* Grab the signal mask */
87 /* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */
88 add x2, x0, #UCONTEXT_SIGMASK
92 mov x8, SYS_ify (rt_sigprocmask)
98 bl JUMPTARGET (__setcontext)
103 b C_SYMBOL_NAME(__syscall_error)
105 /* The oucp context is restored here via an indirect branch,
106 x1 must be restored too which has the real return address. */
110 PSEUDO_END (__swapcontext)
111 weak_alias (__swapcontext, swapcontext)