| 1 | /* The find command. |
| 2 | |
| 3 | Copyright (C) 2008-2016 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 "gdbcmd.h" |
| 24 | #include "value.h" |
| 25 | #include "target.h" |
| 26 | #include "cli/cli-utils.h" |
| 27 | #include <algorithm> |
| 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 = (gdb_byte *) 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 | + std::max (TYPE_LENGTH (t), |
| 183 | (unsigned) sizeof (int64_t))); |
| 184 | if (pattern_buf_size_need > pattern_buf_size) |
| 185 | { |
| 186 | size_t current_offset = pattern_buf_end - pattern_buf; |
| 187 | |
| 188 | pattern_buf_size = pattern_buf_size_need * 2; |
| 189 | pattern_buf = (gdb_byte *) xrealloc (pattern_buf, pattern_buf_size); |
| 190 | pattern_buf_end = pattern_buf + current_offset; |
| 191 | } |
| 192 | |
| 193 | if (size != '\0') |
| 194 | { |
| 195 | x = value_as_long (v); |
| 196 | switch (size) |
| 197 | { |
| 198 | case 'b': |
| 199 | *pattern_buf_end++ = x; |
| 200 | break; |
| 201 | case 'h': |
| 202 | put_bits (x, pattern_buf_end, 16, big_p); |
| 203 | pattern_buf_end += sizeof (int16_t); |
| 204 | break; |
| 205 | case 'w': |
| 206 | put_bits (x, pattern_buf_end, 32, big_p); |
| 207 | pattern_buf_end += sizeof (int32_t); |
| 208 | break; |
| 209 | case 'g': |
| 210 | put_bits (x, pattern_buf_end, 64, big_p); |
| 211 | pattern_buf_end += sizeof (int64_t); |
| 212 | break; |
| 213 | } |
| 214 | } |
| 215 | else |
| 216 | { |
| 217 | memcpy (pattern_buf_end, value_contents (v), TYPE_LENGTH (t)); |
| 218 | pattern_buf_end += TYPE_LENGTH (t); |
| 219 | } |
| 220 | |
| 221 | if (*s == ',') |
| 222 | ++s; |
| 223 | s = skip_spaces_const (s); |
| 224 | } |
| 225 | |
| 226 | if (pattern_buf_end == pattern_buf) |
| 227 | error (_("Missing search pattern.")); |
| 228 | |
| 229 | pattern_len = pattern_buf_end - pattern_buf; |
| 230 | |
| 231 | if (search_space_len < pattern_len) |
| 232 | error (_("Search space too small to contain pattern.")); |
| 233 | |
| 234 | *max_countp = max_count; |
| 235 | *pattern_bufp = pattern_buf; |
| 236 | *pattern_lenp = pattern_len; |
| 237 | *start_addrp = start_addr; |
| 238 | *search_space_lenp = search_space_len; |
| 239 | |
| 240 | /* We successfully parsed the arguments, leave the freeing of PATTERN_BUF |
| 241 | to the caller now. */ |
| 242 | discard_cleanups (old_cleanups); |
| 243 | } |
| 244 | |
| 245 | static void |
| 246 | find_command (char *args, int from_tty) |
| 247 | { |
| 248 | struct gdbarch *gdbarch = get_current_arch (); |
| 249 | bfd_boolean big_p = gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG; |
| 250 | /* Command line parameters. |
| 251 | These are initialized to avoid uninitialized warnings from -Wall. */ |
| 252 | ULONGEST max_count = 0; |
| 253 | gdb_byte *pattern_buf = 0; |
| 254 | ULONGEST pattern_len = 0; |
| 255 | CORE_ADDR start_addr = 0; |
| 256 | ULONGEST search_space_len = 0; |
| 257 | /* End of command line parameters. */ |
| 258 | unsigned int found_count; |
| 259 | CORE_ADDR last_found_addr; |
| 260 | struct cleanup *old_cleanups; |
| 261 | |
| 262 | parse_find_args (args, &max_count, &pattern_buf, &pattern_len, |
| 263 | &start_addr, &search_space_len, big_p); |
| 264 | |
| 265 | old_cleanups = make_cleanup (free_current_contents, &pattern_buf); |
| 266 | |
| 267 | /* Perform the search. */ |
| 268 | |
| 269 | found_count = 0; |
| 270 | last_found_addr = 0; |
| 271 | |
| 272 | while (search_space_len >= pattern_len |
| 273 | && found_count < max_count) |
| 274 | { |
| 275 | /* Offset from start of this iteration to the next iteration. */ |
| 276 | ULONGEST next_iter_incr; |
| 277 | CORE_ADDR found_addr; |
| 278 | int found = target_search_memory (start_addr, search_space_len, |
| 279 | pattern_buf, pattern_len, &found_addr); |
| 280 | |
| 281 | if (found <= 0) |
| 282 | break; |
| 283 | |
| 284 | print_address (gdbarch, found_addr, gdb_stdout); |
| 285 | printf_filtered ("\n"); |
| 286 | ++found_count; |
| 287 | last_found_addr = found_addr; |
| 288 | |
| 289 | /* Begin next iteration at one byte past this match. */ |
| 290 | next_iter_incr = (found_addr - start_addr) + 1; |
| 291 | |
| 292 | /* For robustness, we don't let search_space_len go -ve here. */ |
| 293 | if (search_space_len >= next_iter_incr) |
| 294 | search_space_len -= next_iter_incr; |
| 295 | else |
| 296 | search_space_len = 0; |
| 297 | start_addr += next_iter_incr; |
| 298 | } |
| 299 | |
| 300 | /* Record and print the results. */ |
| 301 | |
| 302 | set_internalvar_integer (lookup_internalvar ("numfound"), found_count); |
| 303 | if (found_count > 0) |
| 304 | { |
| 305 | struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr; |
| 306 | |
| 307 | set_internalvar (lookup_internalvar ("_"), |
| 308 | value_from_pointer (ptr_type, last_found_addr)); |
| 309 | } |
| 310 | |
| 311 | if (found_count == 0) |
| 312 | printf_filtered ("Pattern not found.\n"); |
| 313 | else |
| 314 | printf_filtered ("%d pattern%s found.\n", found_count, |
| 315 | found_count > 1 ? "s" : ""); |
| 316 | |
| 317 | do_cleanups (old_cleanups); |
| 318 | } |
| 319 | |
| 320 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 321 | extern initialize_file_ftype _initialize_mem_search; |
| 322 | |
| 323 | void |
| 324 | _initialize_mem_search (void) |
| 325 | { |
| 326 | add_cmd ("find", class_vars, find_command, _("\ |
| 327 | Search memory for a sequence of bytes.\n\ |
| 328 | Usage:\nfind \ |
| 329 | [/size-char] [/max-count] start-address, end-address, expr1 [, expr2 ...]\n\ |
| 330 | find [/size-char] [/max-count] start-address, +length, expr1 [, expr2 ...]\n\ |
| 331 | size-char is one of b,h,w,g for 8,16,32,64 bit values respectively,\n\ |
| 332 | and if not specified the size is taken from the type of the expression\n\ |
| 333 | in the current language.\n\ |
| 334 | Note that this means for example that in the case of C-like languages\n\ |
| 335 | a search for an untyped 0x42 will search for \"(int) 0x42\"\n\ |
| 336 | which is typically four bytes.\n\ |
| 337 | \n\ |
| 338 | The address of the last match is stored as the value of \"$_\".\n\ |
| 339 | Convenience variable \"$numfound\" is set to the number of matches."), |
| 340 | &cmdlist); |
| 341 | } |