| 1 | /* Target-dependent code for i386 BSD's. |
| 2 | Copyright 2001 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 19 | Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "frame.h" |
| 23 | #include "gdbcore.h" |
| 24 | #include "regcache.h" |
| 25 | |
| 26 | /* Support for signal handlers. */ |
| 27 | |
| 28 | /* Range in which to find the signaltramp routine, traditionally found |
| 29 | on the use stack, just below the user area. Initialized to values |
| 30 | that work for NetBSD and FreeBSD. */ |
| 31 | |
| 32 | CORE_ADDR i386bsd_sigtramp_start = 0xbfbfdf20; |
| 33 | CORE_ADDR i386bsd_sigtramp_end = 0xbfbfdff0; |
| 34 | |
| 35 | /* Return whether PC is in a BSD sigtramp routine. */ |
| 36 | |
| 37 | int |
| 38 | i386bsd_in_sigtramp (CORE_ADDR pc, char *name) |
| 39 | { |
| 40 | return (pc >= i386bsd_sigtramp_start && pc < i386bsd_sigtramp_end); |
| 41 | } |
| 42 | |
| 43 | /* Offset in the sigcontext structure of the program counter. |
| 44 | Initialized to the value from 4.4 BSD Lite. */ |
| 45 | int i386bsd_sigcontext_pc_offset = 20; |
| 46 | |
| 47 | /* Assuming FRAME is for a BSD sigtramp routine, return the address of |
| 48 | the associated sigcontext structure. */ |
| 49 | |
| 50 | static CORE_ADDR |
| 51 | i386bsd_sigcontext_addr (struct frame_info *frame) |
| 52 | { |
| 53 | if (frame->next) |
| 54 | /* If this isn't the top frame, the next frame must be for the |
| 55 | signal handler itself. A pointer to the sigcontext structure |
| 56 | is passed as the third argument to the signal handler. */ |
| 57 | return read_memory_unsigned_integer (frame->next->frame + 16, 4); |
| 58 | |
| 59 | /* This is the top frame. We'll have to find the address of the |
| 60 | sigcontext structure by looking at the stack pointer. */ |
| 61 | return read_memory_unsigned_integer (read_register (SP_REGNUM) + 8, 4); |
| 62 | } |
| 63 | |
| 64 | /* Assuming FRAME is for a BSD sigtramp routine, return the saved |
| 65 | program counter. */ |
| 66 | |
| 67 | static CORE_ADDR |
| 68 | i386bsd_sigtramp_saved_pc (struct frame_info *frame) |
| 69 | { |
| 70 | CORE_ADDR addr; |
| 71 | addr = i386bsd_sigcontext_addr (frame); |
| 72 | return read_memory_unsigned_integer (addr + i386bsd_sigcontext_pc_offset, 4); |
| 73 | } |
| 74 | |
| 75 | /* Return the saved program counter for FRAME. */ |
| 76 | |
| 77 | CORE_ADDR |
| 78 | i386bsd_frame_saved_pc (struct frame_info *frame) |
| 79 | { |
| 80 | if (frame->signal_handler_caller) |
| 81 | return i386bsd_sigtramp_saved_pc (frame); |
| 82 | |
| 83 | return read_memory_unsigned_integer (frame->frame + 4, 4); |
| 84 | } |