1 /* The find command. 2 3 Copyright (C) 2008-2013 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 #include "cli/cli-utils.h" 28 29 /* Copied from bfd_put_bits. */ 30 31 static void 32 put_bits (bfd_uint64_t data, gdb_byte *buf, int bits, bfd_boolean big_p) 33 { 34 int i; 35 int bytes; 36 37 gdb_assert (bits % 8 == 0); 38 39 bytes = bits / 8; 40 for (i = 0; i < bytes; i++) 41 { 42 int index = big_p ? bytes - i - 1 : i; 43 44 buf[index] = data & 0xff; 45 data >>= 8; 46 } 47 } 48 49 /* Subroutine of find_command to simplify it. 50 Parse the arguments of the "find" command. */ 51 52 static void 53 parse_find_args (char *args, ULONGEST *max_countp, 54 gdb_byte **pattern_bufp, ULONGEST *pattern_lenp, 55 CORE_ADDR *start_addrp, ULONGEST *search_space_lenp, 56 bfd_boolean big_p) 57 { 58 /* Default to using the specified type. */ 59 char size = '\0'; 60 ULONGEST max_count = ~(ULONGEST) 0; 61 /* Buffer to hold the search pattern. */ 62 gdb_byte *pattern_buf; 63 /* Current size of search pattern buffer. 64 We realloc space as needed. */ 65 #define INITIAL_PATTERN_BUF_SIZE 100 66 ULONGEST pattern_buf_size = INITIAL_PATTERN_BUF_SIZE; 67 /* Pointer to one past the last in-use part of pattern_buf. */ 68 gdb_byte *pattern_buf_end; 69 ULONGEST pattern_len; 70 CORE_ADDR start_addr; 71 ULONGEST search_space_len; 72 const char *s = args; 73 struct cleanup *old_cleanups; 74 struct value *v; 75 76 if (args == NULL) 77 error (_("Missing search parameters.")); 78 79 pattern_buf = xmalloc (pattern_buf_size); 80 pattern_buf_end = pattern_buf; 81 old_cleanups = make_cleanup (free_current_contents, &pattern_buf); 82 83 /* Get search granularity and/or max count if specified. 84 They may be specified in either order, together or separately. */ 85 86 while (*s == '/') 87 { 88 ++s; 89 90 while (*s != '\0' && *s != '/' && !isspace (*s)) 91 { 92 if (isdigit (*s)) 93 { 94 max_count = atoi (s); 95 while (isdigit (*s)) 96 ++s; 97 continue; 98 } 99 100 switch (*s) 101 { 102 case 'b': 103 case 'h': 104 case 'w': 105 case 'g': 106 size = *s++; 107 break; 108 default: 109 error (_("Invalid size granularity.")); 110 } 111 } 112 113 s = skip_spaces_const (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 s = skip_spaces_const (s); 124 125 if (*s == '+') 126 { 127 LONGEST len; 128 129 ++s; 130 v = parse_to_comma_and_eval (&s); 131 len = value_as_long (v); 132 if (len == 0) 133 { 134 do_cleanups (old_cleanups); 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 precedes 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 " 160 "computation, choose smaller range.")); 161 } 162 163 if (*s == ',') 164 ++s; 165 166 /* Fetch the search string. */ 167 168 while (*s != '\0') 169 { 170 LONGEST x; 171 struct type *t; 172 ULONGEST pattern_buf_size_need; 173 174 s = skip_spaces_const (s); 175 176 v = parse_to_comma_and_eval (&s); 177 t = value_type (v); 178 179 /* Keep it simple and assume size == 'g' when watching for when we 180 need to grow the pattern buf. */ 181 pattern_buf_size_need = (pattern_buf_end - pattern_buf 182 + max (TYPE_LENGTH (t), sizeof (int64_t))); 183 if (pattern_buf_size_need > pattern_buf_size) 184 { 185 size_t current_offset = pattern_buf_end - pattern_buf; 186 187 pattern_buf_size = pattern_buf_size_need * 2; 188 pattern_buf = xrealloc (pattern_buf, pattern_buf_size); 189 pattern_buf_end = pattern_buf + current_offset; 190 } 191 192 if (size != '\0') 193 { 194 x = value_as_long (v); 195 switch (size) 196 { 197 case 'b': 198 *pattern_buf_end++ = x; 199 break; 200 case 'h': 201 put_bits (x, pattern_buf_end, 16, big_p); 202 pattern_buf_end += sizeof (int16_t); 203 break; 204 case 'w': 205 put_bits (x, pattern_buf_end, 32, big_p); 206 pattern_buf_end += sizeof (int32_t); 207 break; 208 case 'g': 209 put_bits (x, pattern_buf_end, 64, big_p); 210 pattern_buf_end += sizeof (int64_t); 211 break; 212 } 213 } 214 else 215 { 216 memcpy (pattern_buf_end, value_contents (v), TYPE_LENGTH (t)); 217 pattern_buf_end += TYPE_LENGTH (t); 218 } 219 220 if (*s == ',') 221 ++s; 222 s = skip_spaces_const (s); 223 } 224 225 if (pattern_buf_end == pattern_buf) 226 error (_("Missing search pattern.")); 227 228 pattern_len = pattern_buf_end - pattern_buf; 229 230 if (search_space_len < pattern_len) 231 error (_("Search space too small to contain pattern.")); 232 233 *max_countp = max_count; 234 *pattern_bufp = pattern_buf; 235 *pattern_lenp = pattern_len; 236 *start_addrp = start_addr; 237 *search_space_lenp = search_space_len; 238 239 /* We successfully parsed the arguments, leave the freeing of PATTERN_BUF 240 to the caller now. */ 241 discard_cleanups (old_cleanups); 242 } 243 244 static void 245 find_command (char *args, int from_tty) 246 { 247 struct gdbarch *gdbarch = get_current_arch (); 248 bfd_boolean big_p = gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG; 249 /* Command line parameters. 250 These are initialized to avoid uninitialized warnings from -Wall. */ 251 ULONGEST max_count = 0; 252 gdb_byte *pattern_buf = 0; 253 ULONGEST pattern_len = 0; 254 CORE_ADDR start_addr = 0; 255 ULONGEST search_space_len = 0; 256 /* End of command line parameters. */ 257 unsigned int found_count; 258 CORE_ADDR last_found_addr; 259 struct cleanup *old_cleanups; 260 261 parse_find_args (args, &max_count, &pattern_buf, &pattern_len, 262 &start_addr, &search_space_len, big_p); 263 264 old_cleanups = make_cleanup (free_current_contents, &pattern_buf); 265 266 /* Perform the search. */ 267 268 found_count = 0; 269 last_found_addr = 0; 270 271 while (search_space_len >= pattern_len 272 && found_count < max_count) 273 { 274 /* Offset from start of this iteration to the next iteration. */ 275 ULONGEST next_iter_incr; 276 CORE_ADDR found_addr; 277 int found = target_search_memory (start_addr, search_space_len, 278 pattern_buf, pattern_len, &found_addr); 279 280 if (found <= 0) 281 break; 282 283 print_address (gdbarch, found_addr, gdb_stdout); 284 printf_filtered ("\n"); 285 ++found_count; 286 last_found_addr = found_addr; 287 288 /* Begin next iteration at one byte past this match. */ 289 next_iter_incr = (found_addr - start_addr) + 1; 290 291 /* For robustness, we don't let search_space_len go -ve here. */ 292 if (search_space_len >= next_iter_incr) 293 search_space_len -= next_iter_incr; 294 else 295 search_space_len = 0; 296 start_addr += next_iter_incr; 297 } 298 299 /* Record and print the results. */ 300 301 set_internalvar_integer (lookup_internalvar ("numfound"), found_count); 302 if (found_count > 0) 303 { 304 struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr; 305 306 set_internalvar (lookup_internalvar ("_"), 307 value_from_pointer (ptr_type, last_found_addr)); 308 } 309 310 if (found_count == 0) 311 printf_filtered ("Pattern not found.\n"); 312 else 313 printf_filtered ("%d pattern%s found.\n", found_count, 314 found_count > 1 ? "s" : ""); 315 316 do_cleanups (old_cleanups); 317 } 318 319 /* Provide a prototype to silence -Wmissing-prototypes. */ 320 extern initialize_file_ftype _initialize_mem_search; 321 322 void 323 _initialize_mem_search (void) 324 { 325 add_cmd ("find", class_vars, find_command, _("\ 326 Search memory for a sequence of bytes.\n\ 327 Usage:\nfind \ 328 [/size-char] [/max-count] start-address, end-address, expr1 [, expr2 ...]\n\ 329 find [/size-char] [/max-count] start-address, +length, expr1 [, expr2 ...]\n\ 330 size-char is one of b,h,w,g for 8,16,32,64 bit values respectively,\n\ 331 and if not specified the size is taken from the type of the expression\n\ 332 in the current language.\n\ 333 Note that this means for example that in the case of C-like languages\n\ 334 a search for an untyped 0x42 will search for \"(int) 0x42\"\n\ 335 which is typically four bytes.\n\ 336 \n\ 337 The address of the last match is stored as the value of \"$_\".\n\ 338 Convenience variable \"$numfound\" is set to the number of matches."), 339 &cmdlist); 340 } 341