From edefb593e2398530fe5b28d12761158ac1eedbae Mon Sep 17 00:00:00 2001 From: Andreas Schwab Date: Tue, 19 Nov 2002 23:14:45 +0000 Subject: * m68klinux-nat.c (IS_SIGTRAMP, IS_RT_SIGTRAMP) (m68k_linux_in_sigtramp, SIGCONTEXT_PC_OFFSET) (UCONTEXT_PC_OFFSET, m68k_linux_sigtramp_saved_pc) (m68k_linux_frame_saved_pc): Move to ... * m68klinux-tdep.c: ... here. New file. * Makefile.in (m68klinux-tdep.o): Add dependencies. * config/m68k/linux.mt (TDEPFILES): Add m68klinux-tdep.o. --- gdb/m68klinux-tdep.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 gdb/m68klinux-tdep.c (limited to 'gdb/m68klinux-tdep.c') diff --git a/gdb/m68klinux-tdep.c b/gdb/m68klinux-tdep.c new file mode 100644 index 00000000000..c4ae867f177 --- /dev/null +++ b/gdb/m68klinux-tdep.c @@ -0,0 +1,124 @@ +/* Motorola m68k target-dependent support for GNU/Linux. + + Copyright 1996, 1998, 2000, 2001, 2002 Free Software Foundation, + Inc. + + This file is part of GDB. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include "defs.h" +#include "gdbcore.h" +#include "frame.h" +#include "target.h" + + +/* Check whether insn1 and insn2 are parts of a signal trampoline. */ + +#define IS_SIGTRAMP(insn1, insn2) \ + (/* addaw #20,sp; moveq #119,d0; trap #0 */ \ + (insn1 == 0xdefc0014 && insn2 == 0x70774e40) \ + /* moveq #119,d0; trap #0 */ \ + || insn1 == 0x70774e40) + +#define IS_RT_SIGTRAMP(insn1, insn2) \ + (/* movel #173,d0; trap #0 */ \ + (insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \ + /* moveq #82,d0; notb d0; trap #0 */ \ + || (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40)) + +/* Return non-zero if PC points into the signal trampoline. For the sake + of m68k_linux_frame_saved_pc we also distinguish between non-RT and RT + signal trampolines. */ + +int +m68k_linux_in_sigtramp (CORE_ADDR pc) +{ + CORE_ADDR sp; + char buf[12]; + unsigned long insn0, insn1, insn2; + + if (read_memory_nobpt (pc - 4, buf, sizeof (buf))) + return 0; + insn1 = extract_unsigned_integer (buf + 4, 4); + insn2 = extract_unsigned_integer (buf + 8, 4); + if (IS_SIGTRAMP (insn1, insn2)) + return 1; + if (IS_RT_SIGTRAMP (insn1, insn2)) + return 2; + + insn0 = extract_unsigned_integer (buf, 4); + if (IS_SIGTRAMP (insn0, insn1)) + return 1; + if (IS_RT_SIGTRAMP (insn0, insn1)) + return 2; + + insn0 = (insn0 << 16) | (insn1 >> 16); + insn1 = (insn1 << 16) | (insn2 >> 16); + if (IS_SIGTRAMP (insn0, insn1)) + return 1; + if (IS_RT_SIGTRAMP (insn0, insn1)) + return 2; + + return 0; +} + +/* Offset to saved PC in sigcontext, from . */ +#define SIGCONTEXT_PC_OFFSET 26 + +/* Offset to saved PC in ucontext, from . */ +#define UCONTEXT_PC_OFFSET 88 + +/* Get saved user PC for sigtramp from sigcontext or ucontext. */ + +static CORE_ADDR +m68k_linux_sigtramp_saved_pc (struct frame_info *frame) +{ + CORE_ADDR sigcontext_addr; + char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT]; + int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT; + int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT; + + /* Get sigcontext address, it is the third parameter on the stack. */ + if (frame->next) + sigcontext_addr = read_memory_integer (FRAME_ARGS_ADDRESS (frame->next) + + FRAME_ARGS_SKIP + + sigcontext_offs, + ptrbytes); + else + sigcontext_addr = read_memory_integer (read_register (SP_REGNUM) + + sigcontext_offs, + ptrbytes); + + /* Don't cause a memory_error when accessing sigcontext in case the + stack layout has changed or the stack is corrupt. */ + if (m68k_linux_in_sigtramp (frame->pc) == 2) + target_read_memory (sigcontext_addr + UCONTEXT_PC_OFFSET, buf, ptrbytes); + else + target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes); + return extract_unsigned_integer (buf, ptrbytes); +} + +/* Return the saved program counter for FRAME. */ + +CORE_ADDR +m68k_linux_frame_saved_pc (struct frame_info *frame) +{ + if (get_frame_type (frame) == SIGTRAMP_FRAME) + return m68k_linux_sigtramp_saved_pc (frame); + + return read_memory_integer (frame->frame + 4, 4); +} -- cgit v1.2.1