| 1 | /* Copyright (C) 1998-2022 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 | /* To enable unwinding through the signal frame without special hackery |
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| 21 | elsewhere, describe the entire struct sigcontext with unwind info. |
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| 22 | |
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| 23 | In order to minimize the size of the encoding, we set the CFA to the |
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| 24 | end of the sigcontext, which makes all of the registers have small |
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| 25 | negative offsets from that. */ |
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| 26 | |
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| 27 | .macro SIGCONTEXT_REGS_I base, from=0 |
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| 28 | cfi_offset (\from, \base + (4 + \from) * 8) |
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| 29 | .if 30-\from |
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| 30 | SIGCONTEXT_REGS_I \base, "(\from+1)" |
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| 31 | .endif |
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| 32 | .endm |
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| 33 | |
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| 34 | .macro SIGCONTEXT_REGS_F base, from=32 |
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| 35 | cfi_offset (\from, \base + (4 + 1 + \from) * 8) |
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| 36 | .if 62-\from |
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| 37 | SIGCONTEXT_REGS_F \base, "(\from+1)" |
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| 38 | .endif |
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| 39 | .endm |
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| 40 | |
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| 41 | .macro SIGCONTEXT_REGS base |
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| 42 | SIGCONTEXT_REGS_I \base |
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| 43 | SIGCONTEXT_REGS_F \base |
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| 44 | cfi_offset (63, \base + (4 + 32 + 1 + 32) * 8) |
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| 45 | cfi_offset (64, \base + 2 * 8) |
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| 46 | .endm |
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| 47 | |
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| 48 | cfi_startproc |
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| 49 | cfi_return_column (64) |
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| 50 | .cfi_signal_frame |
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| 51 | SIGCONTEXT_REGS -648 |
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| 52 | cfi_def_cfa_offset (648) |
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| 53 | |
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| 54 | /* While this frame is marked as a signal frame, that only applies |
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| 55 | to how this return address is handled for the outer frame. |
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| 56 | The return address that arrived here, from the inner frame, is |
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| 57 | not marked as a signal frame and so the unwinder still tries to |
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| 58 | subtract 1 to examine the presumed call insn. Thus we must |
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| 59 | extend the unwind info to a nop before the start. */ |
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| 60 | nop |
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| 61 | .align 4 |
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| 62 | |
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| 63 | __syscall_sigreturn: |
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| 64 | mov sp, a0 |
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| 65 | ldi v0, __NR_sigreturn |
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| 66 | callsys |
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| 67 | .size __syscall_sigreturn, .-__syscall_sigreturn |
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| 68 | .type __syscall_sigreturn, @function |
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| 69 | .global __syscall_sigreturn; |
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| 70 | .hidden __syscall_sigreturn; |
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| 71 | |
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| 72 | /* See above wrt including the nop. */ |
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| 73 | cfi_def_cfa_offset (176 + 648) |
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| 74 | nop |
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| 75 | .align 4 |
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| 76 | |
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| 77 | __syscall_rt_sigreturn: |
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| 78 | mov sp,a0 |
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| 79 | ldi v0,__NR_rt_sigreturn |
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| 80 | callsys |
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| 81 | .size __syscall_rt_sigreturn, .-__syscall_rt_sigreturn |
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| 82 | .type __syscall_rt_sigreturn, @function |
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| 83 | .global __syscall_rt_sigreturn; |
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| 84 | .hidden __syscall_rt_sigreturn; |
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| 85 | |
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| 86 | cfi_endproc |
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| 87 | |
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