1/* Modify saved context. 2 Copyright (C) 2015-2021 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 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 1091: 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 124PSEUDO_END (__swapcontext) 125weak_alias (__swapcontext, swapcontext) 126