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Diffstat (limited to 'gdb/i386fbsd-nat.c')
-rw-r--r-- | gdb/i386fbsd-nat.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/gdb/i386fbsd-nat.c b/gdb/i386fbsd-nat.c new file mode 100644 index 0000000..1c19ac8 --- /dev/null +++ b/gdb/i386fbsd-nat.c @@ -0,0 +1,102 @@ +/* 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 +} |