gdb/x86-fbsd-nat.c

   1 /* Native-dependent code for FreeBSD x86.
   2
   3    Copyright (C) 2022 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 "x86-fbsd-nat.h"
  22
  23 /* Implement the virtual fbsd_nat_target::low_new_fork method.  */
  24
  25 void
  26 x86_fbsd_nat_target::low_new_fork (ptid_t parent, pid_t child)
  27 {
  28   struct x86_debug_reg_state *parent_state, *child_state;
  29
  30   /* If there is no parent state, no watchpoints nor breakpoints have
  31      been set, so there is nothing to do.  */
  32   parent_state = x86_lookup_debug_reg_state (parent.pid ());
  33   if (parent_state == nullptr)
  34     return;
  35
  36   /* The kernel clears debug registers in the new child process after
  37      fork, but GDB core assumes the child inherits the watchpoints/hw
  38      breakpoints of the parent, and will remove them all from the
  39      forked off process.  Copy the debug registers mirrors into the
  40      new process so that all breakpoints and watchpoints can be
  41      removed together.  */
  42
  43   child_state = x86_debug_reg_state (child);
  44   *child_state = *parent_state;
  45 }