1/* $NetBSD: __sigtramp2.S,v 1.5 2021/11/27 10:00:01 skrll Exp $ */ 2 3/*- 4 * Copyright (c) 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#include "SYS.h" 33#include "assym.h" 34 35#if defined(LIBC_SCCS) && !defined(lint) 36__RCSID("$NetBSD: __sigtramp2.S,v 1.5 2021/11/27 10:00:01 skrll Exp $") 37#endif /* LIBC_SCCS && !lint */ 38 39/* 40 * On entry to user space, stack and registers look like: 41 * 42 * r3 signal number 43 * r4 pointer to siginfo structure 44 * r5 pointer to ucontext structure 45 * r30 pointer to ucontext structure 46 * srr0 address of handler 47 * lr address of this trampoline 48 * 49 * We use r30 as the CFA base register since it's been conveniently set up 50 * for us that way. The DWARF register numbers used in the .eh_frame are: 51 * 52 * 0 - 31 GPRs 53 * 32 - 63 FPRs 54 * 65 LR 55 * 66 CTR 56 * 68-75 CRs 57 * 76 XER 58 * 77 - 108 AltiVec regs 59 * 99 signal trampoline return address 60 * 109 VRSAVE 61 * 110 VCSR 62 * 63 * N.B. Only one CR slot is used (CR2) in the SVR4 ABI. 64 */ 65 66#define DWARF_LR_REG 65 67#define DWARF_CTR_REG 66 68#define DWARF_CR2_REG 70 69#define DWARF_XER_REG 76 70#define DWARF_SIGRETURN_REG 99 71 72#define CFI_OFFSET_DWARF_REG(d, r) .cfi_offset d, r * 4 73#define CFI_OFFSET(r) CFI_OFFSET_DWARF_REG(r, r) 74 75 .text 76 .cfi_startproc simple 77 .cfi_signal_frame 78 .cfi_def_cfa _REG_R30, UC_GREGS 79 CFI_OFFSET(_REG_R0) 80 CFI_OFFSET(_REG_R1) 81 CFI_OFFSET(_REG_R2) 82 CFI_OFFSET(_REG_R3) 83 CFI_OFFSET(_REG_R4) 84 CFI_OFFSET(_REG_R5) 85 CFI_OFFSET(_REG_R6) 86 CFI_OFFSET(_REG_R7) 87 CFI_OFFSET(_REG_R8) 88 CFI_OFFSET(_REG_R9) 89 CFI_OFFSET(_REG_R10) 90 CFI_OFFSET(_REG_R11) 91 CFI_OFFSET(_REG_R12) 92 CFI_OFFSET(_REG_R13) 93 CFI_OFFSET(_REG_R14) 94 CFI_OFFSET(_REG_R15) 95 CFI_OFFSET(_REG_R16) 96 CFI_OFFSET(_REG_R17) 97 CFI_OFFSET(_REG_R18) 98 CFI_OFFSET(_REG_R19) 99 CFI_OFFSET(_REG_R20) 100 CFI_OFFSET(_REG_R21) 101 CFI_OFFSET(_REG_R22) 102 CFI_OFFSET(_REG_R23) 103 CFI_OFFSET(_REG_R24) 104 CFI_OFFSET(_REG_R25) 105 CFI_OFFSET(_REG_R26) 106 CFI_OFFSET(_REG_R27) 107 CFI_OFFSET(_REG_R28) 108 CFI_OFFSET(_REG_R29) 109 CFI_OFFSET(_REG_R30) 110 CFI_OFFSET(_REG_R31) 111 CFI_OFFSET_DWARF_REG(DWARF_CR2_REG, _REG_CR) 112 CFI_OFFSET_DWARF_REG(DWARF_LR_REG, _REG_LR) 113 CFI_OFFSET_DWARF_REG(DWARF_CTR_REG, _REG_CTR) 114 CFI_OFFSET_DWARF_REG(DWARF_XER_REG, _REG_XER) 115 .cfi_return_column DWARF_SIGRETURN_REG 116 CFI_OFFSET_DWARF_REG(DWARF_SIGRETURN_REG, _REG_PC) 117 118/* 119 * The unwind entry includes one instruction slot prior to the trampoline 120 * because the unwinder will look up to (return PC - 1 insn) while unwinding. 121 * Normally this would be the jump / branch, but since there isn't one in 122 * this case, we place an explicit nop there instead. 123 */ 124 nop 125 126ENTRY_NOPROFILE(__sigtramp_siginfo_2) 127 mr %r3,%r30 /* restore ucontext pointer */ 128 _DOSYSCALL(setcontext) /* restore machine state */ 129 _DOSYSCALL(exit) /* or exit with errno if failed */ 130 .cfi_endproc 131END(__sigtramp_siginfo_2) 132