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45 lines
1.9 KiB
C
45 lines
1.9 KiB
C
/* Restartable Sequences Linux riscv architecture header.
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Copyright (C) 2021-2025 Free Software Foundation, Inc.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <bits/endian.h>
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#ifndef _SYS_RSEQ_H
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# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
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#endif
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/* RSEQ_SIG is a signature required before each abort handler code.
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It is a 32-bit value that maps to actual architecture code compiled
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into applications and libraries. It needs to be defined for each
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architecture. When choosing this value, it needs to be taken into
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account that generating invalid instructions may have ill effects on
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tools like objdump, and may also have impact on the CPU speculative
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execution efficiency in some cases.
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Select the instruction "csrw mhartid, x0" as the RSEQ_SIG. Unlike
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other architectures, the ebreak instruction has no immediate field for
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distinguishing purposes. Hence, ebreak is not suitable as RSEQ_SIG.
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"csrw mhartid, x0" can also satisfy the RSEQ requirement because it
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is an uncommon instruction and will raise an illegal instruction
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exception when executed in all modes. */
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#if __BYTE_ORDER == __LITTLE_ENDIAN
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#define RSEQ_SIG 0xf1401073
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#else
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/* RSEQ is currently only supported on Little-Endian. */
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#endif
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