103 lines
3.3 KiB
C
103 lines
3.3 KiB
C
/* Native-dependent code for FreeBSD/i386.
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Copyright 2001 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 2 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, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "inferior.h"
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#include "regcache.h"
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#include <sys/types.h>
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#include <sys/ptrace.h>
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#include <sys/sysctl.h>
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/* Prevent warning from -Wmissing-prototypes. */
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void _initialize_i386fbsd_nat (void);
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/* Resume execution of the inferior process.
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If STEP is nonzero, single-step it.
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If SIGNAL is nonzero, give it that signal. */
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void
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child_resume (ptid_t ptid, int step, enum target_signal signal)
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{
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pid_t pid = ptid_get_pid (ptid);
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int request = PT_STEP;
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if (pid == -1)
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/* Resume all threads. This only gets used in the non-threaded
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case, where "resume all threads" and "resume inferior_ptid" are
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the same. */
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pid = ptid_get_pid (inferior_ptid);
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if (!step)
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{
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unsigned int eflags;
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/* Workaround for a bug in FreeBSD. Make sure that the trace
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flag is off when doing a continue. There is a code path
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through the kernel which leaves the flag set when it should
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have been cleared. If a process has a signal pending (such
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as SIGALRM) and we do a PT_STEP, the process never really has
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a chance to run because the kernel needs to notify the
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debugger that a signal is being sent. Therefore, the process
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never goes through the kernel's trap() function which would
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normally clear it. */
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eflags = read_register (PS_REGNUM);
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if (eflags & 0x0100)
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write_register (PS_REGNUM, eflags & ~0x0100);
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request = PT_CONTINUE;
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}
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/* An addres of (caddr_t) 1 tells ptrace to continue from where it
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was. (If GDB wanted it to start some other way, we have already
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written a new PC value to the child.) */
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if (ptrace (request, pid, (caddr_t) 1,
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target_signal_to_host (signal)) == -1)
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perror_with_name ("ptrace");
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}
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void
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_initialize_i386fbsd_nat (void)
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{
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/* FreeBSD provides a kern.ps_strings sysctl that we can use to
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locate the sigtramp. That way we can still recognize a sigtramp
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if it's location is changed in a new kernel. Of course this is
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still based on the assumption that the sigtramp is placed
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directly under the location where the program arguments and
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environment can be found. */
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#ifdef KERN_PS_STRINGS
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{
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int mib[2];
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int ps_strings;
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size_t len;
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mib[0] = CTL_KERN;
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mib[1] = KERN_PS_STRINGS;
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len = sizeof (ps_strings);
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if (sysctl (mib, 2, &ps_strings, &len, NULL, 0) == 0)
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{
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i386bsd_sigtramp_start = ps_strings - 128;
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i386bsd_sigtramp_end = ps_strings;
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}
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}
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#endif
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}
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