1 /* The find command. 2 3 Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 #include "defs.h" 21 #include "arch-utils.h" 22 #include <ctype.h> 23 #include "gdb_string.h" 24 #include "gdbcmd.h" 25 #include "value.h" 26 #include "target.h" 27 28 /* Copied from bfd_put_bits. */ 29 30 static void 31 put_bits (bfd_uint64_t data, char *buf, int bits, bfd_boolean big_p) 32 { 33 int i; 34 int bytes; 35 36 gdb_assert (bits % 8 == 0); 37 38 bytes = bits / 8; 39 for (i = 0; i < bytes; i++) 40 { 41 int index = big_p ? bytes - i - 1 : i; 42 43 buf[index] = data & 0xff; 44 data >>= 8; 45 } 46 } 47 48 /* Subroutine of find_command to simplify it. 49 Parse the arguments of the "find" command. */ 50 51 static void 52 parse_find_args (char *args, ULONGEST *max_countp, 53 char **pattern_bufp, ULONGEST *pattern_lenp, 54 CORE_ADDR *start_addrp, ULONGEST *search_space_lenp, 55 bfd_boolean big_p) 56 { 57 /* Default to using the specified type. */ 58 char size = '\0'; 59 ULONGEST max_count = ~(ULONGEST) 0; 60 /* Buffer to hold the search pattern. */ 61 char *pattern_buf; 62 /* Current size of search pattern buffer. 63 We realloc space as needed. */ 64 #define INITIAL_PATTERN_BUF_SIZE 100 65 ULONGEST pattern_buf_size = INITIAL_PATTERN_BUF_SIZE; 66 /* Pointer to one past the last in-use part of pattern_buf. */ 67 char *pattern_buf_end; 68 ULONGEST pattern_len; 69 CORE_ADDR start_addr; 70 ULONGEST search_space_len; 71 char *s = args; 72 struct cleanup *old_cleanups; 73 struct value *v; 74 75 if (args == NULL) 76 error (_("Missing search parameters.")); 77 78 pattern_buf = xmalloc (pattern_buf_size); 79 pattern_buf_end = pattern_buf; 80 old_cleanups = make_cleanup (free_current_contents, &pattern_buf); 81 82 /* Get search granularity and/or max count if specified. 83 They may be specified in either order, together or separately. */ 84 85 while (*s == '/') 86 { 87 ++s; 88 89 while (*s != '\0' && *s != '/' && !isspace (*s)) 90 { 91 if (isdigit (*s)) 92 { 93 max_count = atoi (s); 94 while (isdigit (*s)) 95 ++s; 96 continue; 97 } 98 99 switch (*s) 100 { 101 case 'b': 102 case 'h': 103 case 'w': 104 case 'g': 105 size = *s++; 106 break; 107 default: 108 error (_("Invalid size granularity.")); 109 } 110 } 111 112 while (isspace (*s)) 113 ++s; 114 } 115 116 /* Get the search range. */ 117 118 v = parse_to_comma_and_eval (&s); 119 start_addr = value_as_address (v); 120 121 if (*s == ',') 122 ++s; 123 while (isspace (*s)) 124 ++s; 125 126 if (*s == '+') 127 { 128 LONGEST len; 129 130 ++s; 131 v = parse_to_comma_and_eval (&s); 132 len = value_as_long (v); 133 if (len == 0) 134 { 135 printf_filtered (_("Empty search range.\n")); 136 return; 137 } 138 if (len < 0) 139 error (_("Invalid length.")); 140 /* Watch for overflows. */ 141 if (len > CORE_ADDR_MAX 142 || (start_addr + len - 1) < start_addr) 143 error (_("Search space too large.")); 144 search_space_len = len; 145 } 146 else 147 { 148 CORE_ADDR end_addr; 149 150 v = parse_to_comma_and_eval (&s); 151 end_addr = value_as_address (v); 152 if (start_addr > end_addr) 153 error (_("Invalid search space, end preceeds start.")); 154 search_space_len = end_addr - start_addr + 1; 155 /* We don't support searching all of memory 156 (i.e. start=0, end = 0xff..ff). 157 Bail to avoid overflows later on. */ 158 if (search_space_len == 0) 159 error (_("Overflow in address range computation, choose smaller range.")); 160 } 161 162 if (*s == ',') 163 ++s; 164 165 /* Fetch the search string. */ 166 167 while (*s != '\0') 168 { 169 LONGEST x; 170 int val_bytes; 171 172 while (isspace (*s)) 173 ++s; 174 175 v = parse_to_comma_and_eval (&s); 176 val_bytes = TYPE_LENGTH (value_type (v)); 177 178 /* Keep it simple and assume size == 'g' when watching for when we 179 need to grow the pattern buf. */ 180 if ((pattern_buf_end - pattern_buf + max (val_bytes, sizeof (int64_t))) 181 > pattern_buf_size) 182 { 183 size_t current_offset = pattern_buf_end - pattern_buf; 184 185 pattern_buf_size *= 2; 186 pattern_buf = xrealloc (pattern_buf, pattern_buf_size); 187 pattern_buf_end = pattern_buf + current_offset; 188 } 189 190 if (size != '\0') 191 { 192 x = value_as_long (v); 193 switch (size) 194 { 195 case 'b': 196 *pattern_buf_end++ = x; 197 break; 198 case 'h': 199 put_bits (x, pattern_buf_end, 16, big_p); 200 pattern_buf_end += sizeof (int16_t); 201 break; 202 case 'w': 203 put_bits (x, pattern_buf_end, 32, big_p); 204 pattern_buf_end += sizeof (int32_t); 205 break; 206 case 'g': 207 put_bits (x, pattern_buf_end, 64, big_p); 208 pattern_buf_end += sizeof (int64_t); 209 break; 210 } 211 } 212 else 213 { 214 memcpy (pattern_buf_end, value_contents (v), val_bytes); 215 pattern_buf_end += val_bytes; 216 } 217 218 if (*s == ',') 219 ++s; 220 while (isspace (*s)) 221 ++s; 222 } 223 224 if (pattern_buf_end == pattern_buf) 225 error (_("Missing search pattern.")); 226 227 pattern_len = pattern_buf_end - pattern_buf; 228 229 if (search_space_len < pattern_len) 230 error (_("Search space too small to contain pattern.")); 231 232 *max_countp = max_count; 233 *pattern_bufp = pattern_buf; 234 *pattern_lenp = pattern_len; 235 *start_addrp = start_addr; 236 *search_space_lenp = search_space_len; 237 238 /* We successfully parsed the arguments, leave the freeing of PATTERN_BUF 239 to the caller now. */ 240 discard_cleanups (old_cleanups); 241 } 242 243 static void 244 find_command (char *args, int from_tty) 245 { 246 struct gdbarch *gdbarch = get_current_arch (); 247 bfd_boolean big_p = gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG; 248 /* Command line parameters. 249 These are initialized to avoid uninitialized warnings from -Wall. */ 250 ULONGEST max_count = 0; 251 char *pattern_buf = 0; 252 ULONGEST pattern_len = 0; 253 CORE_ADDR start_addr = 0; 254 ULONGEST search_space_len = 0; 255 /* End of command line parameters. */ 256 unsigned int found_count; 257 CORE_ADDR last_found_addr; 258 struct cleanup *old_cleanups; 259 260 parse_find_args (args, &max_count, &pattern_buf, &pattern_len, 261 &start_addr, &search_space_len, big_p); 262 263 old_cleanups = make_cleanup (free_current_contents, &pattern_buf); 264 265 /* Perform the search. */ 266 267 found_count = 0; 268 last_found_addr = 0; 269 270 while (search_space_len >= pattern_len 271 && found_count < max_count) 272 { 273 /* Offset from start of this iteration to the next iteration. */ 274 ULONGEST next_iter_incr; 275 CORE_ADDR found_addr; 276 int found = target_search_memory (start_addr, search_space_len, 277 pattern_buf, pattern_len, &found_addr); 278 279 if (found <= 0) 280 break; 281 282 print_address (gdbarch, found_addr, gdb_stdout); 283 printf_filtered ("\n"); 284 ++found_count; 285 last_found_addr = found_addr; 286 287 /* Begin next iteration at one byte past this match. */ 288 next_iter_incr = (found_addr - start_addr) + 1; 289 290 /* For robustness, we don't let search_space_len go -ve here. */ 291 if (search_space_len >= next_iter_incr) 292 search_space_len -= next_iter_incr; 293 else 294 search_space_len = 0; 295 start_addr += next_iter_incr; 296 } 297 298 /* Record and print the results. */ 299 300 set_internalvar_integer (lookup_internalvar ("numfound"), found_count); 301 if (found_count > 0) 302 { 303 struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr; 304 305 set_internalvar (lookup_internalvar ("_"), 306 value_from_pointer (ptr_type, last_found_addr)); 307 } 308 309 if (found_count == 0) 310 printf_filtered ("Pattern not found.\n"); 311 else 312 printf_filtered ("%d pattern%s found.\n", found_count, 313 found_count > 1 ? "s" : ""); 314 315 do_cleanups (old_cleanups); 316 } 317 318 /* Provide a prototype to silence -Wmissing-prototypes. */ 319 extern initialize_file_ftype _initialize_mem_search; 320 321 void 322 _initialize_mem_search (void) 323 { 324 add_cmd ("find", class_vars, find_command, _("\ 325 Search memory for a sequence of bytes.\n\ 326 Usage:\n\ 327 find [/size-char] [/max-count] start-address, end-address, expr1 [, expr2 ...]\n\ 328 find [/size-char] [/max-count] start-address, +length, expr1 [, expr2 ...]\n\ 329 size-char is one of b,h,w,g for 8,16,32,64 bit values respectively,\n\ 330 and if not specified the size is taken from the type of the expression\n\ 331 in the current language.\n\ 332 Note that this means for example that in the case of C-like languages\n\ 333 a search for an untyped 0x42 will search for \"(int) 0x42\"\n\ 334 which is typically four bytes.\n\ 335 \n\ 336 The address of the last match is stored as the value of \"$_\".\n\ 337 Convenience variable \"$numfound\" is set to the number of matches."), 338 &cmdlist); 339 } 340