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