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This moves the simple_search_memory function to a new file, gdbsupport/search.cc. The API is slightly changed to make it more general. This generality is useful for wiring it to gdbserver, and also for unit testing. gdb/ChangeLog 2020-10-07 Tom Tromey <tromey@adacore.com> * target.h (simple_search_memory): Don't declare. * target.c (simple_search_memory): Move to gdbsupport. (default_search_memory): Update. * remote.c (remote_target::search_memory): Update. gdbsupport/ChangeLog 2020-10-07 Tom Tromey <tromey@adacore.com> * Makefile.in: Rebuild. * Makefile.am (libgdbsupport_a_SOURCES): Add search.cc. * search.h: New file. * search.cc: New file.users/ARM/morello-binutils-gdb-master
Tom Tromey
6 years ago
9 changed files with 197 additions and 113 deletions
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/* Target memory searching
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Copyright (C) 2020 Free Software Foundation, Inc. |
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This file is part of GDB. |
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This program is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 3 of the License, or |
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(at your option) any later version. |
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This program is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU General Public License for more details. |
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You should have received a copy of the GNU General Public License |
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "gdbsupport/common-defs.h" |
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#include "gdbsupport/search.h" |
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#include "gdbsupport/byte-vector.h" |
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/* This implements a basic search of memory, reading target memory and
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performing the search here (as opposed to performing the search in on the |
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target side with, for example, gdbserver). */ |
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int |
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simple_search_memory |
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(gdb::function_view<target_read_memory_ftype> read_memory, |
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CORE_ADDR start_addr, ULONGEST search_space_len, |
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const gdb_byte *pattern, ULONGEST pattern_len, |
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CORE_ADDR *found_addrp) |
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{ |
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const unsigned chunk_size = SEARCH_CHUNK_SIZE; |
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/* Buffer to hold memory contents for searching. */ |
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unsigned search_buf_size; |
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search_buf_size = chunk_size + pattern_len - 1; |
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/* No point in trying to allocate a buffer larger than the search space. */ |
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if (search_space_len < search_buf_size) |
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search_buf_size = search_space_len; |
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gdb::byte_vector search_buf (search_buf_size); |
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/* Prime the search buffer. */ |
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if (!read_memory (start_addr, search_buf.data (), search_buf_size)) |
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{ |
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warning (_("Unable to access %s bytes of target " |
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"memory at %s, halting search."), |
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pulongest (search_buf_size), hex_string (start_addr)); |
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return -1; |
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} |
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/* Perform the search.
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The loop is kept simple by allocating [N + pattern-length - 1] bytes. |
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When we've scanned N bytes we copy the trailing bytes to the start and |
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read in another N bytes. */ |
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while (search_space_len >= pattern_len) |
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{ |
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gdb_byte *found_ptr; |
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unsigned nr_search_bytes |
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= std::min (search_space_len, (ULONGEST) search_buf_size); |
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found_ptr = (gdb_byte *) memmem (search_buf.data (), nr_search_bytes, |
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pattern, pattern_len); |
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if (found_ptr != NULL) |
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{ |
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CORE_ADDR found_addr = start_addr + (found_ptr - search_buf.data ()); |
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*found_addrp = found_addr; |
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return 1; |
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} |
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/* Not found in this chunk, skip to next chunk. */ |
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/* Don't let search_space_len wrap here, it's unsigned. */ |
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if (search_space_len >= chunk_size) |
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search_space_len -= chunk_size; |
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else |
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search_space_len = 0; |
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if (search_space_len >= pattern_len) |
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{ |
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unsigned keep_len = search_buf_size - chunk_size; |
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CORE_ADDR read_addr = start_addr + chunk_size + keep_len; |
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int nr_to_read; |
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/* Copy the trailing part of the previous iteration to the front
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of the buffer for the next iteration. */ |
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gdb_assert (keep_len == pattern_len - 1); |
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if (keep_len > 0) |
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memcpy (&search_buf[0], &search_buf[chunk_size], keep_len); |
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nr_to_read = std::min (search_space_len - keep_len, |
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(ULONGEST) chunk_size); |
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if (!read_memory (read_addr, &search_buf[keep_len], nr_to_read)) |
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{ |
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warning (_("Unable to access %s bytes of target " |
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"memory at %s, halting search."), |
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plongest (nr_to_read), |
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hex_string (read_addr)); |
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return -1; |
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} |
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start_addr += chunk_size; |
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} |
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} |
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/* Not found. */ |
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return 0; |
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} |
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/* Copyright (C) 2020 Free Software Foundation, Inc.
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This file is part of GDB. |
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This program is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 3 of the License, or |
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(at your option) any later version. |
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This program is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU General Public License for more details. |
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You should have received a copy of the GNU General Public License |
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#ifndef COMMON_SEARCH_H |
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#define COMMON_SEARCH_H |
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#include "gdbsupport/function-view.h" |
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/* This is needed by the unit test, so appears here. */ |
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#define SEARCH_CHUNK_SIZE 16000 |
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/* The type of a callback function that can be used to read memory.
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Note that target_read_memory is not used here, because gdbserver |
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wants to be able to examine trace data when searching, and |
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target_read_memory does not do this. */ |
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typedef bool target_read_memory_ftype (CORE_ADDR, gdb_byte *, size_t); |
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/* Utility implementation of searching memory. */ |
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extern int simple_search_memory |
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(gdb::function_view<target_read_memory_ftype> read_memory, |
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CORE_ADDR start_addr, |
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ULONGEST search_space_len, |
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const gdb_byte *pattern, |
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ULONGEST pattern_len, |
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CORE_ADDR *found_addrp); |
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#endif /* COMMON_SEARCH_H */ |
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