123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120 |
- /* Target memory searching
- Copyright (C) 2020-2022 Free Software Foundation, Inc.
- This file is part of GDB.
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- #include "gdbsupport/common-defs.h"
- #include "gdbsupport/search.h"
- #include "gdbsupport/byte-vector.h"
- /* This implements a basic search of memory, reading target memory and
- performing the search here (as opposed to performing the search in on the
- target side with, for example, gdbserver). */
- int
- simple_search_memory
- (gdb::function_view<target_read_memory_ftype> read_memory,
- CORE_ADDR start_addr, ULONGEST search_space_len,
- const gdb_byte *pattern, ULONGEST pattern_len,
- CORE_ADDR *found_addrp)
- {
- const unsigned chunk_size = SEARCH_CHUNK_SIZE;
- /* Buffer to hold memory contents for searching. */
- unsigned search_buf_size;
- search_buf_size = chunk_size + pattern_len - 1;
- /* No point in trying to allocate a buffer larger than the search space. */
- if (search_space_len < search_buf_size)
- search_buf_size = search_space_len;
- gdb::byte_vector search_buf (search_buf_size);
- /* Prime the search buffer. */
- if (!read_memory (start_addr, search_buf.data (), search_buf_size))
- {
- warning (_("Unable to access %s bytes of target "
- "memory at %s, halting search."),
- pulongest (search_buf_size), hex_string (start_addr));
- return -1;
- }
- /* Perform the search.
- The loop is kept simple by allocating [N + pattern-length - 1] bytes.
- When we've scanned N bytes we copy the trailing bytes to the start and
- read in another N bytes. */
- while (search_space_len >= pattern_len)
- {
- gdb_byte *found_ptr;
- unsigned nr_search_bytes
- = std::min (search_space_len, (ULONGEST) search_buf_size);
- found_ptr = (gdb_byte *) memmem (search_buf.data (), nr_search_bytes,
- pattern, pattern_len);
- if (found_ptr != NULL)
- {
- CORE_ADDR found_addr = start_addr + (found_ptr - search_buf.data ());
- *found_addrp = found_addr;
- return 1;
- }
- /* Not found in this chunk, skip to next chunk. */
- /* Don't let search_space_len wrap here, it's unsigned. */
- if (search_space_len >= chunk_size)
- search_space_len -= chunk_size;
- else
- search_space_len = 0;
- if (search_space_len >= pattern_len)
- {
- unsigned keep_len = search_buf_size - chunk_size;
- CORE_ADDR read_addr = start_addr + chunk_size + keep_len;
- int nr_to_read;
- /* Copy the trailing part of the previous iteration to the front
- of the buffer for the next iteration. */
- gdb_assert (keep_len == pattern_len - 1);
- if (keep_len > 0)
- memcpy (&search_buf[0], &search_buf[chunk_size], keep_len);
- nr_to_read = std::min (search_space_len - keep_len,
- (ULONGEST) chunk_size);
- if (!read_memory (read_addr, &search_buf[keep_len], nr_to_read))
- {
- warning (_("Unable to access %s bytes of target "
- "memory at %s, halting search."),
- plongest (nr_to_read),
- hex_string (read_addr));
- return -1;
- }
- start_addr += chunk_size;
- }
- }
- /* Not found. */
- return 0;
- }
|