| /* Native-dependent code for FreeBSD/i386. |
| |
| Copyright (C) 2001, 2002, 2003, 2004 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., 51 Franklin Street, Fifth Floor, |
| Boston, MA 02110-1301, USA. */ |
| |
| #include "defs.h" |
| #include "inferior.h" |
| #include "regcache.h" |
| #include "target.h" |
| |
| #include <sys/types.h> |
| #include <sys/ptrace.h> |
| #include <sys/sysctl.h> |
| |
| #include "fbsd-nat.h" |
| #include "i386-tdep.h" |
| #include "i386bsd-nat.h" |
| |
| /* Resume execution of the inferior process. If STEP is nonzero, |
| single-step it. If SIGNAL is nonzero, give it that signal. */ |
| |
| static void |
| i386fbsd_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) |
| { |
| ULONGEST 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. */ |
| |
| regcache_cooked_read_unsigned (current_regcache, I386_EFLAGS_REGNUM, |
| &eflags); |
| if (eflags & 0x0100) |
| regcache_cooked_write_unsigned (current_regcache, I386_EFLAGS_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")); |
| } |
| |
| |
| /* Support for debugging kernel virtual memory images. */ |
| |
| #include <sys/types.h> |
| #include <machine/pcb.h> |
| |
| #include "bsd-kvm.h" |
| |
| static int |
| i386fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb) |
| { |
| /* The following is true for FreeBSD 4.7: |
| |
| The pcb contains %eip, %ebx, %esp, %ebp, %esi, %edi and %gs. |
| This accounts for all callee-saved registers specified by the |
| psABI and then some. Here %esp contains the stack pointer at the |
| point just after the call to cpu_switch(). From this information |
| we reconstruct the register state as it would look when we just |
| returned from cpu_switch(). */ |
| |
| /* The stack pointer shouldn't be zero. */ |
| if (pcb->pcb_esp == 0) |
| return 0; |
| |
| pcb->pcb_esp += 4; |
| regcache_raw_supply (regcache, I386_EDI_REGNUM, &pcb->pcb_edi); |
| regcache_raw_supply (regcache, I386_ESI_REGNUM, &pcb->pcb_esi); |
| regcache_raw_supply (regcache, I386_EBP_REGNUM, &pcb->pcb_ebp); |
| regcache_raw_supply (regcache, I386_ESP_REGNUM, &pcb->pcb_esp); |
| regcache_raw_supply (regcache, I386_EBX_REGNUM, &pcb->pcb_ebx); |
| regcache_raw_supply (regcache, I386_EIP_REGNUM, &pcb->pcb_eip); |
| regcache_raw_supply (regcache, I386_GS_REGNUM, &pcb->pcb_gs); |
| |
| return 1; |
| } |
| |
| |
| /* Prevent warning from -Wmissing-prototypes. */ |
| void _initialize_i386fbsd_nat (void); |
| |
| void |
| _initialize_i386fbsd_nat (void) |
| { |
| struct target_ops *t; |
| |
| /* Add some extra features to the common *BSD/i386 target. */ |
| t = i386bsd_target (); |
| t->to_resume = i386fbsd_resume; |
| t->to_pid_to_exec_file = fbsd_pid_to_exec_file; |
| t->to_find_memory_regions = fbsd_find_memory_regions; |
| t->to_make_corefile_notes = fbsd_make_corefile_notes; |
| add_target (t); |
| |
| /* Support debugging kernel virtual memory images. */ |
| bsd_kvm_add_target (i386fbsd_supply_pcb); |
| |
| /* FreeBSD provides a kern.ps_strings sysctl that we can use to |
| locate the sigtramp. That way we can still recognize a sigtramp |
| if its 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]; |
| u_long 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) |
| { |
| i386fbsd_sigtramp_start_addr = ps_strings - 128; |
| i386fbsd_sigtramp_end_addr = ps_strings; |
| } |
| } |
| #endif |
| } |