/* $NetBSD: __sigtramp2.S,v 1.5 2021/11/21 23:58:09 thorpej Exp $ */ /*- * Copyright (c) 2003 The NetBSD Foundation, Inc. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include "SYS.h" #include "assym.h" /* * The m68k signal trampoline is invoked only to return from * the signal; the kernel calls the signal handler directly. * * On entry, stack looks like: * * ucontext structure [12+sizeof(siginfo_t)] * siginfo structure [12] * pointer to ucontext structure [8] * pointer to siginfo structure [4] * sp-> signal number [0] * * The DWARF register numbers are 0-7 (dX), 8-15 (aX), 16-23 (fpX), * which maps nicely to _REG_D[0-7] and _REG_A[0-7]. For m68k, there * is a DWARF pseudo-register for the return address, and additionally * another DWARF pseudo-register for signal handler return addresses. * We will specify both return address pseudo-registers (without * explicitly specifying .cfi_return_column) to keep the compiler * run-time happy with whichever one it decides to use. */ #define DWARF_RETURN_REG 24 #if defined(__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__) #define DWARF_SIGRETURN_REG __LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__ #else #define DWARF_SIGRETURN_REG 25 #endif #define CFI_OFFSET_DWARF_REG(d, r) .cfi_offset d, r * 4 #define CFI_OFFSET(r) CFI_OFFSET_DWARF_REG(r, r) .text .cfi_startproc simple .cfi_signal_frame .cfi_def_cfa _REG_A7, 12 + SIZEOF_SIGINFO + UC_GREGS CFI_OFFSET(_REG_D0) CFI_OFFSET(_REG_D1) CFI_OFFSET(_REG_D2) CFI_OFFSET(_REG_D3) CFI_OFFSET(_REG_D4) CFI_OFFSET(_REG_D5) CFI_OFFSET(_REG_D6) CFI_OFFSET(_REG_D7) CFI_OFFSET(_REG_A0) CFI_OFFSET(_REG_A1) CFI_OFFSET(_REG_A2) CFI_OFFSET(_REG_A3) CFI_OFFSET(_REG_A4) CFI_OFFSET(_REG_A5) CFI_OFFSET(_REG_A6) CFI_OFFSET(_REG_A7) CFI_OFFSET_DWARF_REG(DWARF_RETURN_REG, _REG_PC) CFI_OFFSET_DWARF_REG(DWARF_SIGRETURN_REG, _REG_PC) /* * The unwind entry includes one instruction slot prior to the trampoline * because the unwinder will look up to (return PC - 1 insn) while unwinding. * Normally this would be the jump / branch, but since there isn't one in * this case, we place an explicit nop there instead. */ nop ENTRY_NOPROFILE(__sigtramp_siginfo_2) movl 8(%sp),%a0 /* get pointer to ucontext */ movl %a0,4(%sp) /* put it in the argument slot */ /* fake return address already there */ SYSTRAP(setcontext) movl %d0,4(%sp) /* error code */ SYSTRAP(exit) /* exit */ .cfi_endproc END(__sigtramp_siginfo_2)
