/* Restartable Sequences Linux s390 architecture header. Copyright (C) 2021-2023 Free Software Foundation, Inc. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see . */ #ifndef _SYS_RSEQ_H # error "Never use directly; include instead." #endif /* RSEQ_SIG is a signature required before each abort handler code. It is a 32-bit value that maps to actual architecture code compiled into applications and libraries. It needs to be defined for each architecture. When choosing this value, it needs to be taken into account that generating invalid instructions may have ill effects on tools like objdump, and may also have impact on the CPU speculative execution efficiency in some cases. RSEQ_SIG uses the trap4 instruction. As Linux does not make use of the access-register mode nor the linkage stack this instruction will always cause a special-operation exception (the trap-enabled bit in the DUCT is and will stay 0). The instruction pattern is b2 ff 0f ff trap4 4095(%r0) */ #define RSEQ_SIG 0xB2FF0FFF