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611cb4a5 DJ |
1 | /* Memory breakpoint operations for the remote server for GDB. |
2 | Copyright 2002 | |
3 | Free Software Foundation, Inc. | |
4 | ||
5 | Contributed by MontaVista Software. | |
6 | ||
7 | This file is part of GDB. | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 2 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program; if not, write to the Free Software | |
21 | Foundation, Inc., 59 Temple Place - Suite 330, | |
22 | Boston, MA 02111-1307, USA. */ | |
23 | ||
24 | #include "server.h" | |
25 | ||
26 | const char *breakpoint_data; | |
27 | int breakpoint_len; | |
28 | ||
29 | #define MAX_BREAKPOINT_LEN 8 | |
30 | ||
31 | struct breakpoint | |
32 | { | |
33 | struct breakpoint *next; | |
34 | CORE_ADDR pc; | |
35 | unsigned char old_data[MAX_BREAKPOINT_LEN]; | |
36 | ||
37 | /* Non-zero iff we are stepping over this breakpoint. */ | |
38 | int reinserting; | |
39 | ||
40 | /* Non-NULL iff this breakpoint was inserted to step over | |
41 | another one. Points to the other breakpoint (which is also | |
42 | in the *next chain somewhere). */ | |
43 | struct breakpoint *breakpoint_to_reinsert; | |
44 | ||
45 | /* Function to call when we hit this breakpoint. */ | |
46 | void (*handler) (CORE_ADDR); | |
47 | }; | |
48 | ||
49 | struct breakpoint *breakpoints; | |
50 | ||
51 | void | |
52 | set_breakpoint_at (CORE_ADDR where, void (*handler) (CORE_ADDR)) | |
53 | { | |
54 | struct breakpoint *bp; | |
55 | ||
56 | if (breakpoint_data == NULL) | |
57 | error ("Target does not support breakpoints."); | |
58 | ||
59 | bp = malloc (sizeof (struct breakpoint)); | |
60 | memset (bp, 0, sizeof (struct breakpoint)); | |
61 | ||
62 | (*the_target->read_memory) (where, bp->old_data, | |
63 | breakpoint_len); | |
64 | (*the_target->write_memory) (where, breakpoint_data, | |
65 | breakpoint_len); | |
66 | ||
67 | bp->pc = where; | |
68 | bp->handler = handler; | |
69 | ||
70 | bp->next = breakpoints; | |
71 | breakpoints = bp; | |
72 | } | |
73 | ||
74 | static void | |
75 | delete_breakpoint (struct breakpoint *bp) | |
76 | { | |
77 | struct breakpoint *cur; | |
78 | ||
79 | if (breakpoints == bp) | |
80 | { | |
81 | breakpoints = bp->next; | |
82 | (*the_target->write_memory) (bp->pc, bp->old_data, | |
83 | breakpoint_len); | |
84 | free (bp); | |
85 | return; | |
86 | } | |
87 | cur = breakpoints; | |
88 | while (cur->next) | |
89 | { | |
90 | if (cur->next == bp) | |
91 | { | |
92 | cur->next = bp->next; | |
93 | (*the_target->write_memory) (bp->pc, bp->old_data, | |
94 | breakpoint_len); | |
95 | free (bp); | |
96 | return; | |
97 | } | |
98 | } | |
99 | warning ("Could not find breakpoint in list."); | |
100 | } | |
101 | ||
102 | static struct breakpoint * | |
103 | find_breakpoint_at (CORE_ADDR where) | |
104 | { | |
105 | struct breakpoint *bp = breakpoints; | |
106 | ||
107 | while (bp != NULL) | |
108 | { | |
109 | if (bp->pc == where) | |
110 | return bp; | |
111 | bp = bp->next; | |
112 | } | |
113 | ||
114 | return NULL; | |
115 | } | |
116 | ||
117 | static void | |
118 | reinsert_breakpoint_handler (CORE_ADDR stop_pc) | |
119 | { | |
120 | struct breakpoint *stop_bp, *orig_bp; | |
121 | ||
122 | stop_bp = find_breakpoint_at (stop_pc); | |
123 | if (stop_bp == NULL) | |
124 | error ("lost the stopping breakpoint."); | |
125 | ||
126 | orig_bp = stop_bp->breakpoint_to_reinsert; | |
127 | if (orig_bp == NULL) | |
128 | error ("no breakpoint to reinsert"); | |
129 | ||
130 | (*the_target->write_memory) (orig_bp->pc, breakpoint_data, | |
131 | breakpoint_len); | |
132 | orig_bp->reinserting = 0; | |
133 | delete_breakpoint (stop_bp); | |
134 | } | |
135 | ||
136 | void | |
137 | reinsert_breakpoint_by_bp (CORE_ADDR stop_pc, CORE_ADDR stop_at) | |
138 | { | |
139 | struct breakpoint *bp, *orig_bp; | |
140 | ||
141 | set_breakpoint_at (stop_at, reinsert_breakpoint_handler); | |
142 | ||
fd3a5ca1 | 143 | orig_bp = find_breakpoint_at (stop_pc); |
611cb4a5 DJ |
144 | if (orig_bp == NULL) |
145 | error ("Could not find original breakpoint in list."); | |
146 | ||
147 | bp = find_breakpoint_at (stop_at); | |
148 | if (bp == NULL) | |
149 | error ("Could not find breakpoint in list (reinserting by breakpoint)."); | |
150 | bp->breakpoint_to_reinsert = orig_bp; | |
151 | ||
152 | (*the_target->write_memory) (orig_bp->pc, orig_bp->old_data, | |
153 | breakpoint_len); | |
154 | orig_bp->reinserting = 1; | |
155 | } | |
156 | ||
157 | void | |
158 | uninsert_breakpoint (CORE_ADDR stopped_at) | |
159 | { | |
160 | struct breakpoint *bp; | |
161 | ||
162 | bp = find_breakpoint_at (stopped_at); | |
163 | if (bp == NULL) | |
164 | error ("Could not find breakpoint in list (uninserting)."); | |
165 | ||
166 | (*the_target->write_memory) (bp->pc, bp->old_data, | |
167 | breakpoint_len); | |
168 | bp->reinserting = 1; | |
169 | } | |
170 | ||
171 | void | |
172 | reinsert_breakpoint (CORE_ADDR stopped_at) | |
173 | { | |
174 | struct breakpoint *bp; | |
175 | ||
176 | bp = find_breakpoint_at (stopped_at); | |
177 | if (bp == NULL) | |
178 | error ("Could not find breakpoint in list (uninserting)."); | |
179 | if (! bp->reinserting) | |
180 | error ("Breakpoint already inserted at reinsert time."); | |
181 | ||
182 | (*the_target->write_memory) (bp->pc, breakpoint_data, | |
183 | breakpoint_len); | |
184 | bp->reinserting = 0; | |
185 | } | |
186 | ||
187 | int | |
188 | check_breakpoints (CORE_ADDR stop_pc) | |
189 | { | |
190 | struct breakpoint *bp; | |
191 | ||
192 | bp = find_breakpoint_at (stop_pc); | |
193 | if (bp == NULL) | |
194 | return 0; | |
195 | if (bp->reinserting) | |
196 | { | |
197 | warning ("Hit a removed breakpoint?"); | |
198 | return 0; | |
199 | } | |
200 | ||
201 | (*bp->handler) (bp->pc); | |
202 | return 1; | |
203 | } | |
204 | ||
205 | void | |
206 | set_breakpoint_data (const char *bp_data, int bp_len) | |
207 | { | |
208 | breakpoint_data = bp_data; | |
209 | breakpoint_len = bp_len; | |
210 | } | |
211 | ||
212 | void | |
213 | check_mem_read (CORE_ADDR mem_addr, char *buf, int mem_len) | |
214 | { | |
215 | struct breakpoint *bp = breakpoints; | |
216 | CORE_ADDR mem_end = mem_addr + mem_len; | |
217 | ||
218 | for (; bp != NULL; bp = bp->next) | |
219 | { | |
220 | CORE_ADDR bp_end = bp->pc + breakpoint_len; | |
221 | CORE_ADDR start, end; | |
222 | int copy_offset, copy_len, buf_offset; | |
223 | ||
224 | if (mem_addr >= bp_end) | |
225 | continue; | |
226 | if (bp->pc >= mem_end) | |
227 | continue; | |
228 | ||
229 | start = bp->pc; | |
230 | if (mem_addr > start) | |
231 | start = mem_addr; | |
232 | ||
233 | end = bp_end; | |
234 | if (end > mem_end) | |
235 | end = mem_end; | |
236 | ||
237 | copy_len = end - start; | |
238 | copy_offset = start - bp->pc; | |
239 | buf_offset = start - mem_addr; | |
240 | ||
241 | memcpy (buf + buf_offset, bp->old_data + copy_offset, copy_len); | |
242 | } | |
243 | } | |
244 | ||
245 | void | |
246 | check_mem_write (CORE_ADDR mem_addr, char *buf, int mem_len) | |
247 | { | |
248 | struct breakpoint *bp = breakpoints; | |
249 | CORE_ADDR mem_end = mem_addr + mem_len; | |
250 | ||
251 | for (; bp != NULL; bp = bp->next) | |
252 | { | |
253 | CORE_ADDR bp_end = bp->pc + breakpoint_len; | |
254 | CORE_ADDR start, end; | |
255 | int copy_offset, copy_len, buf_offset; | |
256 | ||
257 | if (mem_addr >= bp_end) | |
258 | continue; | |
259 | if (bp->pc >= mem_end) | |
260 | continue; | |
261 | ||
262 | start = bp->pc; | |
263 | if (mem_addr > start) | |
264 | start = mem_addr; | |
265 | ||
266 | end = bp_end; | |
267 | if (end > mem_end) | |
268 | end = mem_end; | |
269 | ||
270 | copy_len = end - start; | |
271 | copy_offset = start - bp->pc; | |
272 | buf_offset = start - mem_addr; | |
273 | ||
274 | memcpy (bp->old_data + copy_offset, buf + buf_offset, copy_len); | |
275 | if (bp->reinserting == 0) | |
276 | memcpy (buf + buf_offset, breakpoint_data + copy_offset, copy_len); | |
277 | } | |
278 | } | |
279 | ||
280 |