1/* $NetBSD: __sigtramp2.S,v 1.5 2021/11/21 23:58:09 thorpej Exp $ */ 2 3/*- 4 * Copyright (c) 2003 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#include "SYS.h" 30#include "assym.h" 31 32/* 33 * The m68k signal trampoline is invoked only to return from 34 * the signal; the kernel calls the signal handler directly. 35 * 36 * On entry, stack looks like: 37 * 38 * ucontext structure [12+sizeof(siginfo_t)] 39 * siginfo structure [12] 40 * pointer to ucontext structure [8] 41 * pointer to siginfo structure [4] 42 * sp-> signal number [0] 43 * 44 * The DWARF register numbers are 0-7 (dX), 8-15 (aX), 16-23 (fpX), 45 * which maps nicely to _REG_D[0-7] and _REG_A[0-7]. For m68k, there 46 * is a DWARF pseudo-register for the return address, and additionally 47 * another DWARF pseudo-register for signal handler return addresses. 48 * We will specify both return address pseudo-registers (without 49 * explicitly specifying .cfi_return_column) to keep the compiler 50 * run-time happy with whichever one it decides to use. 51 */ 52 53#define DWARF_RETURN_REG 24 54#if defined(__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__) 55#define DWARF_SIGRETURN_REG __LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__ 56#else 57#define DWARF_SIGRETURN_REG 25 58#endif 59 60#define CFI_OFFSET_DWARF_REG(d, r) .cfi_offset d, r * 4 61#define CFI_OFFSET(r) CFI_OFFSET_DWARF_REG(r, r) 62 63 .text 64 .cfi_startproc simple 65 .cfi_signal_frame 66 .cfi_def_cfa _REG_A7, 12 + SIZEOF_SIGINFO + UC_GREGS 67 CFI_OFFSET(_REG_D0) 68 CFI_OFFSET(_REG_D1) 69 CFI_OFFSET(_REG_D2) 70 CFI_OFFSET(_REG_D3) 71 CFI_OFFSET(_REG_D4) 72 CFI_OFFSET(_REG_D5) 73 CFI_OFFSET(_REG_D6) 74 CFI_OFFSET(_REG_D7) 75 CFI_OFFSET(_REG_A0) 76 CFI_OFFSET(_REG_A1) 77 CFI_OFFSET(_REG_A2) 78 CFI_OFFSET(_REG_A3) 79 CFI_OFFSET(_REG_A4) 80 CFI_OFFSET(_REG_A5) 81 CFI_OFFSET(_REG_A6) 82 CFI_OFFSET(_REG_A7) 83 CFI_OFFSET_DWARF_REG(DWARF_RETURN_REG, _REG_PC) 84 CFI_OFFSET_DWARF_REG(DWARF_SIGRETURN_REG, _REG_PC) 85 86/* 87 * The unwind entry includes one instruction slot prior to the trampoline 88 * because the unwinder will look up to (return PC - 1 insn) while unwinding. 89 * Normally this would be the jump / branch, but since there isn't one in 90 * this case, we place an explicit nop there instead. 91 */ 92 nop 93 94ENTRY_NOPROFILE(__sigtramp_siginfo_2) 95 movl 8(%sp),%a0 /* get pointer to ucontext */ 96 movl %a0,4(%sp) /* put it in the argument slot */ 97 /* fake return address already there */ 98 SYSTRAP(setcontext) 99 movl %d0,4(%sp) /* error code */ 100 SYSTRAP(exit) /* exit */ 101 .cfi_endproc 102END(__sigtramp_siginfo_2) 103