1/* $NetBSD: __sigtramp3.S,v 1.3 2021/11/24 15:05:16 thorpej Exp $ */ 2 3/* 4 * Copyright (c) 2003 Matt Thomas <matt@3am-software.com> 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 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30#include "SYS.h" 31#include "assym.h" 32 33#ifdef SYSLIBC_SCCS 34RCSID("$NetBSD: __sigtramp3.S,v 1.3 2021/11/24 15:05:16 thorpej Exp $") 35#endif 36 37/* 38 * Signal trampoline; registers when called: 39 * pc, psl - obvious 40 * sp, ap - points to a CALLG argument list 41 * fp - address of signal handler 42 * 43 * Stack is set up like so: 44 * ucontext structure 45 * siginfo structure 46 * vvvv CALLG argument list vvvv 47 * 12(ap) -- pointer to ucontext 48 * 8(ap) -- pointer to siginfo 49 * 4(ap) -- signal number 50 * sp -> 0(ap) -- argument count 51 * ^^^^ CALLG argument list ^^^^ 52 * 53 * N.B. all of the DWARF register numbers match our _REG_* constants. 54 * Also notice that while the %ap is adjusted inside the trampoline, 55 * the %sp is not adjusted, and so the CFA base does not change. 56 */ 57 58#define CFI_OFFSET(r) .cfi_offset r, r * 4 59 60 .text 61#if 0 62 .cfi_startproc simple 63 .cfi_signal_frame 64 .cfi_def_cfa _REG_SP, 16 + SIZEOF_SIGINFO + UC_GREGS 65 CFI_OFFSET(_REG_R0) 66 CFI_OFFSET(_REG_R1) 67 CFI_OFFSET(_REG_R2) 68 CFI_OFFSET(_REG_R3) 69 CFI_OFFSET(_REG_R4) 70 CFI_OFFSET(_REG_R5) 71 CFI_OFFSET(_REG_R6) 72 CFI_OFFSET(_REG_R7) 73 CFI_OFFSET(_REG_R8) 74 CFI_OFFSET(_REG_R9) 75 CFI_OFFSET(_REG_R10) 76 CFI_OFFSET(_REG_R11) 77 CFI_OFFSET(_REG_AP) 78 CFI_OFFSET(_REG_FP) 79 CFI_OFFSET(_REG_SP) 80 CFI_OFFSET(_REG_PC) 81 CFI_OFFSET(_REG_PSL) 82#endif 83 84/* 85 * The unwind entry includes one instruction slot prior to the trampoline 86 * because the unwinder will look up to (return PC - 1) while unwinding. 87 * Normally this would be the jump / branch, but since there isn't one in 88 * this case, we place an explicit nop there instead. 89 */ 90 91#if 0 92 nop 93#endif 94 _ALIGN_TEXT 95 96 .globl _C_LABEL(__sigtramp_siginfo_3) 97_C_LABEL(__sigtramp_siginfo_3): 98 nop; nop 99 callg (%ap),(%fp) # use global arg list 100 addl2 $8,%ap # arg is pointer to ucontext 101 SYSTRAP(setcontext) # exit from here 102 halt # illegal insn 103#if 0 104 .cfi_endproc 105#endif 106