| 1 | /* Memory breakpoint operations for the remote server for GDB. |
| 2 | Copyright (C) 2002, 2003, 2005, 2007 Free Software Foundation, Inc. |
| 3 | |
| 4 | Contributed by MontaVista Software. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 2 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| 21 | Boston, MA 02110-1301, USA. */ |
| 22 | |
| 23 | #include "server.h" |
| 24 | |
| 25 | const unsigned char *breakpoint_data; |
| 26 | int breakpoint_len; |
| 27 | |
| 28 | #define MAX_BREAKPOINT_LEN 8 |
| 29 | |
| 30 | struct breakpoint |
| 31 | { |
| 32 | struct breakpoint *next; |
| 33 | CORE_ADDR pc; |
| 34 | unsigned char old_data[MAX_BREAKPOINT_LEN]; |
| 35 | |
| 36 | /* Non-zero iff we are stepping over this breakpoint. */ |
| 37 | int reinserting; |
| 38 | |
| 39 | /* Non-NULL iff this breakpoint was inserted to step over |
| 40 | another one. Points to the other breakpoint (which is also |
| 41 | in the *next chain somewhere). */ |
| 42 | struct breakpoint *breakpoint_to_reinsert; |
| 43 | |
| 44 | /* Function to call when we hit this breakpoint. */ |
| 45 | void (*handler) (CORE_ADDR); |
| 46 | }; |
| 47 | |
| 48 | struct breakpoint *breakpoints; |
| 49 | |
| 50 | void |
| 51 | set_breakpoint_at (CORE_ADDR where, void (*handler) (CORE_ADDR)) |
| 52 | { |
| 53 | struct breakpoint *bp; |
| 54 | |
| 55 | if (breakpoint_data == NULL) |
| 56 | error ("Target does not support breakpoints."); |
| 57 | |
| 58 | bp = malloc (sizeof (struct breakpoint)); |
| 59 | memset (bp, 0, sizeof (struct breakpoint)); |
| 60 | |
| 61 | (*the_target->read_memory) (where, bp->old_data, |
| 62 | breakpoint_len); |
| 63 | (*the_target->write_memory) (where, breakpoint_data, |
| 64 | breakpoint_len); |
| 65 | |
| 66 | bp->pc = where; |
| 67 | bp->handler = handler; |
| 68 | |
| 69 | bp->next = breakpoints; |
| 70 | breakpoints = bp; |
| 71 | } |
| 72 | |
| 73 | static void |
| 74 | delete_breakpoint (struct breakpoint *bp) |
| 75 | { |
| 76 | struct breakpoint *cur; |
| 77 | |
| 78 | if (breakpoints == bp) |
| 79 | { |
| 80 | breakpoints = bp->next; |
| 81 | (*the_target->write_memory) (bp->pc, bp->old_data, |
| 82 | breakpoint_len); |
| 83 | free (bp); |
| 84 | return; |
| 85 | } |
| 86 | cur = breakpoints; |
| 87 | while (cur->next) |
| 88 | { |
| 89 | if (cur->next == bp) |
| 90 | { |
| 91 | cur->next = bp->next; |
| 92 | (*the_target->write_memory) (bp->pc, bp->old_data, |
| 93 | breakpoint_len); |
| 94 | free (bp); |
| 95 | return; |
| 96 | } |
| 97 | } |
| 98 | warning ("Could not find breakpoint in list."); |
| 99 | } |
| 100 | |
| 101 | static struct breakpoint * |
| 102 | find_breakpoint_at (CORE_ADDR where) |
| 103 | { |
| 104 | struct breakpoint *bp = breakpoints; |
| 105 | |
| 106 | while (bp != NULL) |
| 107 | { |
| 108 | if (bp->pc == where) |
| 109 | return bp; |
| 110 | bp = bp->next; |
| 111 | } |
| 112 | |
| 113 | return NULL; |
| 114 | } |
| 115 | |
| 116 | static void |
| 117 | reinsert_breakpoint_handler (CORE_ADDR stop_pc) |
| 118 | { |
| 119 | struct breakpoint *stop_bp, *orig_bp; |
| 120 | |
| 121 | stop_bp = find_breakpoint_at (stop_pc); |
| 122 | if (stop_bp == NULL) |
| 123 | error ("lost the stopping breakpoint."); |
| 124 | |
| 125 | orig_bp = stop_bp->breakpoint_to_reinsert; |
| 126 | if (orig_bp == NULL) |
| 127 | error ("no breakpoint to reinsert"); |
| 128 | |
| 129 | (*the_target->write_memory) (orig_bp->pc, breakpoint_data, |
| 130 | breakpoint_len); |
| 131 | orig_bp->reinserting = 0; |
| 132 | delete_breakpoint (stop_bp); |
| 133 | } |
| 134 | |
| 135 | void |
| 136 | reinsert_breakpoint_by_bp (CORE_ADDR stop_pc, CORE_ADDR stop_at) |
| 137 | { |
| 138 | struct breakpoint *bp, *orig_bp; |
| 139 | |
| 140 | set_breakpoint_at (stop_at, reinsert_breakpoint_handler); |
| 141 | |
| 142 | orig_bp = find_breakpoint_at (stop_pc); |
| 143 | if (orig_bp == NULL) |
| 144 | error ("Could not find original breakpoint in list."); |
| 145 | |
| 146 | bp = find_breakpoint_at (stop_at); |
| 147 | if (bp == NULL) |
| 148 | error ("Could not find breakpoint in list (reinserting by breakpoint)."); |
| 149 | bp->breakpoint_to_reinsert = orig_bp; |
| 150 | |
| 151 | (*the_target->write_memory) (orig_bp->pc, orig_bp->old_data, |
| 152 | breakpoint_len); |
| 153 | orig_bp->reinserting = 1; |
| 154 | } |
| 155 | |
| 156 | void |
| 157 | uninsert_breakpoint (CORE_ADDR stopped_at) |
| 158 | { |
| 159 | struct breakpoint *bp; |
| 160 | |
| 161 | bp = find_breakpoint_at (stopped_at); |
| 162 | if (bp == NULL) |
| 163 | error ("Could not find breakpoint in list (uninserting)."); |
| 164 | |
| 165 | (*the_target->write_memory) (bp->pc, bp->old_data, |
| 166 | breakpoint_len); |
| 167 | bp->reinserting = 1; |
| 168 | } |
| 169 | |
| 170 | void |
| 171 | reinsert_breakpoint (CORE_ADDR stopped_at) |
| 172 | { |
| 173 | struct breakpoint *bp; |
| 174 | |
| 175 | bp = find_breakpoint_at (stopped_at); |
| 176 | if (bp == NULL) |
| 177 | error ("Could not find breakpoint in list (uninserting)."); |
| 178 | if (! bp->reinserting) |
| 179 | error ("Breakpoint already inserted at reinsert time."); |
| 180 | |
| 181 | (*the_target->write_memory) (bp->pc, breakpoint_data, |
| 182 | breakpoint_len); |
| 183 | bp->reinserting = 0; |
| 184 | } |
| 185 | |
| 186 | int |
| 187 | check_breakpoints (CORE_ADDR stop_pc) |
| 188 | { |
| 189 | struct breakpoint *bp; |
| 190 | |
| 191 | bp = find_breakpoint_at (stop_pc); |
| 192 | if (bp == NULL) |
| 193 | return 0; |
| 194 | if (bp->reinserting) |
| 195 | { |
| 196 | warning ("Hit a removed breakpoint?"); |
| 197 | return 0; |
| 198 | } |
| 199 | |
| 200 | (*bp->handler) (bp->pc); |
| 201 | return 1; |
| 202 | } |
| 203 | |
| 204 | void |
| 205 | set_breakpoint_data (const unsigned char *bp_data, int bp_len) |
| 206 | { |
| 207 | breakpoint_data = bp_data; |
| 208 | breakpoint_len = bp_len; |
| 209 | } |
| 210 | |
| 211 | void |
| 212 | check_mem_read (CORE_ADDR mem_addr, unsigned char *buf, int mem_len) |
| 213 | { |
| 214 | struct breakpoint *bp = breakpoints; |
| 215 | CORE_ADDR mem_end = mem_addr + mem_len; |
| 216 | |
| 217 | for (; bp != NULL; bp = bp->next) |
| 218 | { |
| 219 | CORE_ADDR bp_end = bp->pc + breakpoint_len; |
| 220 | CORE_ADDR start, end; |
| 221 | int copy_offset, copy_len, buf_offset; |
| 222 | |
| 223 | if (mem_addr >= bp_end) |
| 224 | continue; |
| 225 | if (bp->pc >= mem_end) |
| 226 | continue; |
| 227 | |
| 228 | start = bp->pc; |
| 229 | if (mem_addr > start) |
| 230 | start = mem_addr; |
| 231 | |
| 232 | end = bp_end; |
| 233 | if (end > mem_end) |
| 234 | end = mem_end; |
| 235 | |
| 236 | copy_len = end - start; |
| 237 | copy_offset = start - bp->pc; |
| 238 | buf_offset = start - mem_addr; |
| 239 | |
| 240 | memcpy (buf + buf_offset, bp->old_data + copy_offset, copy_len); |
| 241 | } |
| 242 | } |
| 243 | |
| 244 | void |
| 245 | check_mem_write (CORE_ADDR mem_addr, unsigned char *buf, int mem_len) |
| 246 | { |
| 247 | struct breakpoint *bp = breakpoints; |
| 248 | CORE_ADDR mem_end = mem_addr + mem_len; |
| 249 | |
| 250 | for (; bp != NULL; bp = bp->next) |
| 251 | { |
| 252 | CORE_ADDR bp_end = bp->pc + breakpoint_len; |
| 253 | CORE_ADDR start, end; |
| 254 | int copy_offset, copy_len, buf_offset; |
| 255 | |
| 256 | if (mem_addr >= bp_end) |
| 257 | continue; |
| 258 | if (bp->pc >= mem_end) |
| 259 | continue; |
| 260 | |
| 261 | start = bp->pc; |
| 262 | if (mem_addr > start) |
| 263 | start = mem_addr; |
| 264 | |
| 265 | end = bp_end; |
| 266 | if (end > mem_end) |
| 267 | end = mem_end; |
| 268 | |
| 269 | copy_len = end - start; |
| 270 | copy_offset = start - bp->pc; |
| 271 | buf_offset = start - mem_addr; |
| 272 | |
| 273 | memcpy (bp->old_data + copy_offset, buf + buf_offset, copy_len); |
| 274 | if (bp->reinserting == 0) |
| 275 | memcpy (buf + buf_offset, breakpoint_data + copy_offset, copy_len); |
| 276 | } |
| 277 | } |