| 1 | /* The find command. |
| 2 | |
| 3 | Copyright (C) 2008-2019 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 | #include "gdbsupport/byte-vector.h" |
| 29 | |
| 30 | /* Copied from bfd_put_bits. */ |
| 31 | |
| 32 | static void |
| 33 | put_bits (bfd_uint64_t data, gdb::byte_vector &buf, int bits, bfd_boolean big_p) |
| 34 | { |
| 35 | int i; |
| 36 | int bytes; |
| 37 | |
| 38 | gdb_assert (bits % 8 == 0); |
| 39 | |
| 40 | bytes = bits / 8; |
| 41 | size_t last = buf.size (); |
| 42 | buf.resize (last + bytes); |
| 43 | for (i = 0; i < bytes; i++) |
| 44 | { |
| 45 | int index = big_p ? bytes - i - 1 : i; |
| 46 | |
| 47 | buf[last + index] = data & 0xff; |
| 48 | data >>= 8; |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | /* Subroutine of find_command to simplify it. |
| 53 | Parse the arguments of the "find" command. */ |
| 54 | |
| 55 | static gdb::byte_vector |
| 56 | parse_find_args (const char *args, ULONGEST *max_countp, |
| 57 | CORE_ADDR *start_addrp, ULONGEST *search_space_lenp, |
| 58 | bfd_boolean big_p) |
| 59 | { |
| 60 | /* Default to using the specified type. */ |
| 61 | char size = '\0'; |
| 62 | ULONGEST max_count = ~(ULONGEST) 0; |
| 63 | /* Buffer to hold the search pattern. */ |
| 64 | gdb::byte_vector pattern_buf; |
| 65 | CORE_ADDR start_addr; |
| 66 | ULONGEST search_space_len; |
| 67 | const char *s = args; |
| 68 | struct value *v; |
| 69 | |
| 70 | if (args == NULL) |
| 71 | error (_("Missing search parameters.")); |
| 72 | |
| 73 | /* Get search granularity and/or max count if specified. |
| 74 | They may be specified in either order, together or separately. */ |
| 75 | |
| 76 | while (*s == '/') |
| 77 | { |
| 78 | ++s; |
| 79 | |
| 80 | while (*s != '\0' && *s != '/' && !isspace (*s)) |
| 81 | { |
| 82 | if (isdigit (*s)) |
| 83 | { |
| 84 | max_count = atoi (s); |
| 85 | while (isdigit (*s)) |
| 86 | ++s; |
| 87 | continue; |
| 88 | } |
| 89 | |
| 90 | switch (*s) |
| 91 | { |
| 92 | case 'b': |
| 93 | case 'h': |
| 94 | case 'w': |
| 95 | case 'g': |
| 96 | size = *s++; |
| 97 | break; |
| 98 | default: |
| 99 | error (_("Invalid size granularity.")); |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | s = skip_spaces (s); |
| 104 | } |
| 105 | |
| 106 | /* Get the search range. */ |
| 107 | |
| 108 | v = parse_to_comma_and_eval (&s); |
| 109 | start_addr = value_as_address (v); |
| 110 | |
| 111 | if (*s == ',') |
| 112 | ++s; |
| 113 | s = skip_spaces (s); |
| 114 | |
| 115 | if (*s == '+') |
| 116 | { |
| 117 | LONGEST len; |
| 118 | |
| 119 | ++s; |
| 120 | v = parse_to_comma_and_eval (&s); |
| 121 | len = value_as_long (v); |
| 122 | if (len == 0) |
| 123 | { |
| 124 | printf_filtered (_("Empty search range.\n")); |
| 125 | return pattern_buf; |
| 126 | } |
| 127 | if (len < 0) |
| 128 | error (_("Invalid length.")); |
| 129 | /* Watch for overflows. */ |
| 130 | if (len > CORE_ADDR_MAX |
| 131 | || (start_addr + len - 1) < start_addr) |
| 132 | error (_("Search space too large.")); |
| 133 | search_space_len = len; |
| 134 | } |
| 135 | else |
| 136 | { |
| 137 | CORE_ADDR end_addr; |
| 138 | |
| 139 | v = parse_to_comma_and_eval (&s); |
| 140 | end_addr = value_as_address (v); |
| 141 | if (start_addr > end_addr) |
| 142 | error (_("Invalid search space, end precedes start.")); |
| 143 | search_space_len = end_addr - start_addr + 1; |
| 144 | /* We don't support searching all of memory |
| 145 | (i.e. start=0, end = 0xff..ff). |
| 146 | Bail to avoid overflows later on. */ |
| 147 | if (search_space_len == 0) |
| 148 | error (_("Overflow in address range " |
| 149 | "computation, choose smaller range.")); |
| 150 | } |
| 151 | |
| 152 | if (*s == ',') |
| 153 | ++s; |
| 154 | |
| 155 | /* Fetch the search string. */ |
| 156 | |
| 157 | while (*s != '\0') |
| 158 | { |
| 159 | LONGEST x; |
| 160 | struct type *t; |
| 161 | |
| 162 | s = skip_spaces (s); |
| 163 | |
| 164 | v = parse_to_comma_and_eval (&s); |
| 165 | t = value_type (v); |
| 166 | |
| 167 | if (size != '\0') |
| 168 | { |
| 169 | x = value_as_long (v); |
| 170 | switch (size) |
| 171 | { |
| 172 | case 'b': |
| 173 | pattern_buf.push_back (x); |
| 174 | break; |
| 175 | case 'h': |
| 176 | put_bits (x, pattern_buf, 16, big_p); |
| 177 | break; |
| 178 | case 'w': |
| 179 | put_bits (x, pattern_buf, 32, big_p); |
| 180 | break; |
| 181 | case 'g': |
| 182 | put_bits (x, pattern_buf, 64, big_p); |
| 183 | break; |
| 184 | } |
| 185 | } |
| 186 | else |
| 187 | { |
| 188 | const gdb_byte *contents = value_contents (v); |
| 189 | pattern_buf.insert (pattern_buf.end (), contents, |
| 190 | contents + TYPE_LENGTH (t)); |
| 191 | } |
| 192 | |
| 193 | if (*s == ',') |
| 194 | ++s; |
| 195 | s = skip_spaces (s); |
| 196 | } |
| 197 | |
| 198 | if (pattern_buf.empty ()) |
| 199 | error (_("Missing search pattern.")); |
| 200 | |
| 201 | if (search_space_len < pattern_buf.size ()) |
| 202 | error (_("Search space too small to contain pattern.")); |
| 203 | |
| 204 | *max_countp = max_count; |
| 205 | *start_addrp = start_addr; |
| 206 | *search_space_lenp = search_space_len; |
| 207 | |
| 208 | return pattern_buf; |
| 209 | } |
| 210 | |
| 211 | static void |
| 212 | find_command (const char *args, int from_tty) |
| 213 | { |
| 214 | struct gdbarch *gdbarch = get_current_arch (); |
| 215 | bfd_boolean big_p = gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG; |
| 216 | /* Command line parameters. |
| 217 | These are initialized to avoid uninitialized warnings from -Wall. */ |
| 218 | ULONGEST max_count = 0; |
| 219 | CORE_ADDR start_addr = 0; |
| 220 | ULONGEST search_space_len = 0; |
| 221 | /* End of command line parameters. */ |
| 222 | unsigned int found_count; |
| 223 | CORE_ADDR last_found_addr; |
| 224 | |
| 225 | gdb::byte_vector pattern_buf = parse_find_args (args, &max_count, |
| 226 | &start_addr, |
| 227 | &search_space_len, |
| 228 | big_p); |
| 229 | |
| 230 | /* Perform the search. */ |
| 231 | |
| 232 | found_count = 0; |
| 233 | last_found_addr = 0; |
| 234 | |
| 235 | while (search_space_len >= pattern_buf.size () |
| 236 | && found_count < max_count) |
| 237 | { |
| 238 | /* Offset from start of this iteration to the next iteration. */ |
| 239 | ULONGEST next_iter_incr; |
| 240 | CORE_ADDR found_addr; |
| 241 | int found = target_search_memory (start_addr, search_space_len, |
| 242 | pattern_buf.data (), |
| 243 | pattern_buf.size (), |
| 244 | &found_addr); |
| 245 | |
| 246 | if (found <= 0) |
| 247 | break; |
| 248 | |
| 249 | print_address (gdbarch, found_addr, gdb_stdout); |
| 250 | printf_filtered ("\n"); |
| 251 | ++found_count; |
| 252 | last_found_addr = found_addr; |
| 253 | |
| 254 | /* Begin next iteration at one byte past this match. */ |
| 255 | next_iter_incr = (found_addr - start_addr) + 1; |
| 256 | |
| 257 | /* For robustness, we don't let search_space_len go -ve here. */ |
| 258 | if (search_space_len >= next_iter_incr) |
| 259 | search_space_len -= next_iter_incr; |
| 260 | else |
| 261 | search_space_len = 0; |
| 262 | start_addr += next_iter_incr; |
| 263 | } |
| 264 | |
| 265 | /* Record and print the results. */ |
| 266 | |
| 267 | set_internalvar_integer (lookup_internalvar ("numfound"), found_count); |
| 268 | if (found_count > 0) |
| 269 | { |
| 270 | struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr; |
| 271 | |
| 272 | set_internalvar (lookup_internalvar ("_"), |
| 273 | value_from_pointer (ptr_type, last_found_addr)); |
| 274 | } |
| 275 | |
| 276 | if (found_count == 0) |
| 277 | printf_filtered ("Pattern not found.\n"); |
| 278 | else |
| 279 | printf_filtered ("%d pattern%s found.\n", found_count, |
| 280 | found_count > 1 ? "s" : ""); |
| 281 | } |
| 282 | |
| 283 | void |
| 284 | _initialize_mem_search (void) |
| 285 | { |
| 286 | add_cmd ("find", class_vars, find_command, _("\ |
| 287 | Search memory for a sequence of bytes.\n\ |
| 288 | Usage:\nfind \ |
| 289 | [/SIZE-CHAR] [/MAX-COUNT] START-ADDRESS, END-ADDRESS, EXPR1 [, EXPR2 ...]\n\ |
| 290 | find [/SIZE-CHAR] [/MAX-COUNT] START-ADDRESS, +LENGTH, EXPR1 [, EXPR2 ...]\n\ |
| 291 | SIZE-CHAR is one of b,h,w,g for 8,16,32,64 bit values respectively,\n\ |
| 292 | and if not specified the size is taken from the type of the expression\n\ |
| 293 | in the current language.\n\ |
| 294 | Note that this means for example that in the case of C-like languages\n\ |
| 295 | a search for an untyped 0x42 will search for \"(int) 0x42\"\n\ |
| 296 | which is typically four bytes, and a search for a string \"hello\" will\n\ |
| 297 | include the trailing '\\0'. The null terminator can be removed from\n\ |
| 298 | searching by using casts, e.g.: {char[5]}\"hello\".\n\ |
| 299 | \n\ |
| 300 | The address of the last match is stored as the value of \"$_\".\n\ |
| 301 | Convenience variable \"$numfound\" is set to the number of matches."), |
| 302 | &cmdlist); |
| 303 | } |