/* Simulate breakpoints by patching locations in the target system, for GDB. Copyright (C) 1990-1993, 1995, 1997-2000, 2002, 2007-2012 Free Software Foundation, Inc. Contributed by Cygnus Support. Written by John Gilmore. 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 "defs.h" /* This file is only useful if BREAKPOINT_FROM_PC is set. If not, we punt. */ #include "symtab.h" #include "breakpoint.h" #include "inferior.h" #include "target.h" #include "gdb_string.h" /* Insert a breakpoint on targets that don't have any better breakpoint support. We read the contents of the target location and stash it, then overwrite it with a breakpoint instruction. BP_TGT->placed_address is the target location in the target machine. BP_TGT->shadow_contents is some memory allocated for saving the target contents. It is guaranteed by the caller to be long enough to save BREAKPOINT_LEN bytes (this is accomplished via BREAKPOINT_MAX). */ int default_memory_insert_breakpoint (struct gdbarch *gdbarch, struct bp_target_info *bp_tgt) { int val; const unsigned char *bp; gdb_byte *readbuf; /* Determine appropriate breakpoint contents and size for this address. */ bp = gdbarch_breakpoint_from_pc (gdbarch, &bp_tgt->placed_address, &bp_tgt->placed_size); if (bp == NULL) error (_("Software breakpoints not implemented for this target.")); /* Save the memory contents in the shadow_contents buffer and then write the breakpoint instruction. */ bp_tgt->shadow_len = bp_tgt->placed_size; readbuf = alloca (bp_tgt->placed_size); val = target_read_memory (bp_tgt->placed_address, readbuf, bp_tgt->placed_size); if (val == 0) { memcpy (bp_tgt->shadow_contents, readbuf, bp_tgt->placed_size); val = target_write_raw_memory (bp_tgt->placed_address, bp, bp_tgt->placed_size); } return val; } int default_memory_remove_breakpoint (struct gdbarch *gdbarch, struct bp_target_info *bp_tgt) { return target_write_raw_memory (bp_tgt->placed_address, bp_tgt->shadow_contents, bp_tgt->placed_size); } int memory_insert_breakpoint (struct gdbarch *gdbarch, struct bp_target_info *bp_tgt) { return gdbarch_memory_insert_breakpoint (gdbarch, bp_tgt); } int memory_remove_breakpoint (struct gdbarch *gdbarch, struct bp_target_info *bp_tgt) { return gdbarch_memory_remove_breakpoint (gdbarch, bp_tgt); }