| 1 | /* Copyright (C) 2012-2022 Free Software Foundation, Inc. |
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| 2 | This file is part of the GNU C Library. |
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| 3 | |
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| 4 | The GNU C Library is free software; you can redistribute it and/or |
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| 5 | modify it under the terms of the GNU Lesser General Public |
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| 6 | License as published by the Free Software Foundation; either |
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| 7 | version 2.1 of the License, or (at your option) any later version. |
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| 8 | |
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| 9 | The GNU C Library is distributed in the hope that it will be useful, |
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 12 | Lesser General Public License for more details. |
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| 13 | |
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| 14 | You should have received a copy of the GNU Lesser General Public |
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| 15 | License along with the GNU C Library; if not, see |
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| 16 | <https://www.gnu.org/licenses/>. */ |
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| 17 | |
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| 18 | #include <sysdep.h> |
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| 19 | |
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| 20 | #include "ucontext_i.h" |
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| 21 | |
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| 22 | .syntax unified |
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| 23 | .text |
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| 24 | |
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| 25 | /* int swapcontext (ucontext_t *oucp, const ucontext_t *ucp) */ |
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| 26 | |
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| 27 | ENTRY(swapcontext) |
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| 28 | |
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| 29 | /* Have getcontext() do most of the work then fix up |
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| 30 | LR afterwards. Save R3 to keep the stack aligned. */ |
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| 31 | push {r0,r1,r3,r14} |
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| 32 | cfi_adjust_cfa_offset (16) |
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| 33 | cfi_rel_offset (r0,0) |
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| 34 | cfi_rel_offset (r1,4) |
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| 35 | cfi_rel_offset (r3,8) |
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| 36 | cfi_rel_offset (r14,12) |
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| 37 | |
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| 38 | bl __getcontext |
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| 39 | mov r4, r0 |
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| 40 | |
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| 41 | pop {r0,r1,r3,r14} |
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| 42 | cfi_adjust_cfa_offset (-16) |
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| 43 | cfi_restore (r0) |
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| 44 | cfi_restore (r1) |
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| 45 | cfi_restore (r3) |
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| 46 | cfi_restore (r14) |
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| 47 | |
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| 48 | /* Exit if getcontext() failed. */ |
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| 49 | cmp r4, #0 |
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| 50 | itt ne |
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| 51 | movne r0, r4 |
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| 52 | RETINSTR(ne, r14) |
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| 53 | |
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| 54 | /* Fix up LR and the PC. */ |
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| 55 | str r13,[r0, #MCONTEXT_ARM_SP] |
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| 56 | str r14,[r0, #MCONTEXT_ARM_LR] |
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| 57 | str r14,[r0, #MCONTEXT_ARM_PC] |
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| 58 | |
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| 59 | /* And swap using swapcontext(). */ |
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| 60 | mov r0, r1 |
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| 61 | b __setcontext |
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| 62 | |
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| 63 | END(swapcontext) |
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| 64 | |
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