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b7247919 MK |
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 | } |