196 lines
5.8 KiB
C
196 lines
5.8 KiB
C
/* Native-dependent code for FreeBSD/i386.
|
||
|
||
Copyright (C) 2001-2017 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 3 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, see <http://www.gnu.org/licenses/>. */
|
||
|
||
#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 <sys/user.h>
|
||
|
||
#include "fbsd-nat.h"
|
||
#include "i386-tdep.h"
|
||
#include "x86-nat.h"
|
||
#include "x86-bsd-nat.h"
|
||
#include "i386-bsd-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 (struct target_ops *ops,
|
||
ptid_t ptid, int step, enum gdb_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)
|
||
{
|
||
struct regcache *regcache = get_current_regcache ();
|
||
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 (regcache, I386_EFLAGS_REGNUM,
|
||
&eflags);
|
||
if (eflags & 0x0100)
|
||
regcache_cooked_write_unsigned (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,
|
||
gdb_signal_to_host (signal)) == -1)
|
||
perror_with_name (("ptrace"));
|
||
}
|
||
|
||
|
||
/* Support for debugging kernel virtual memory images. */
|
||
|
||
#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;
|
||
}
|
||
|
||
|
||
#ifdef PT_GETXSTATE_INFO
|
||
/* Implement the to_read_description method. */
|
||
|
||
static const struct target_desc *
|
||
i386fbsd_read_description (struct target_ops *ops)
|
||
{
|
||
static int xsave_probed;
|
||
static uint64_t xcr0;
|
||
|
||
if (!xsave_probed)
|
||
{
|
||
struct ptrace_xstate_info info;
|
||
|
||
if (ptrace (PT_GETXSTATE_INFO, ptid_get_pid (inferior_ptid),
|
||
(PTRACE_TYPE_ARG3) &info, sizeof (info)) == 0)
|
||
{
|
||
x86bsd_xsave_len = info.xsave_len;
|
||
xcr0 = info.xsave_mask;
|
||
}
|
||
xsave_probed = 1;
|
||
}
|
||
|
||
if (x86bsd_xsave_len == 0)
|
||
xcr0 = X86_XSTATE_SSE_MASK;
|
||
|
||
return i386_target_description (xcr0);
|
||
}
|
||
#endif
|
||
|
||
/* 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 ();
|
||
|
||
#ifdef PT_GETXSTATE_INFO
|
||
t->to_read_description = i386fbsd_read_description;
|
||
#endif
|
||
|
||
t->to_resume = i386fbsd_resume;
|
||
fbsd_nat_add_target (t);
|
||
|
||
/* Support debugging kernel virtual memory images. */
|
||
bsd_kvm_add_target (i386fbsd_supply_pcb);
|
||
|
||
#ifdef KERN_PROC_SIGTRAMP
|
||
/* Normally signal frames are detected via i386fbsd_sigtramp_p.
|
||
However, FreeBSD 9.2 through 10.1 do not include the page holding
|
||
the signal code in core dumps. These releases do provide a
|
||
kern.proc.sigtramp.<pid> sysctl that returns the location of the
|
||
signal trampoline for a running process. We fetch the location
|
||
of the current (gdb) process and use this to identify signal
|
||
frames in core dumps from these releases. */
|
||
{
|
||
int mib[4];
|
||
struct kinfo_sigtramp kst;
|
||
size_t len;
|
||
|
||
mib[0] = CTL_KERN;
|
||
mib[1] = KERN_PROC;
|
||
mib[2] = KERN_PROC_SIGTRAMP;
|
||
mib[3] = getpid ();
|
||
len = sizeof (kst);
|
||
if (sysctl (mib, 4, &kst, &len, NULL, 0) == 0)
|
||
{
|
||
i386fbsd_sigtramp_start_addr = (uintptr_t) kst.ksigtramp_start;
|
||
i386fbsd_sigtramp_end_addr = (uintptr_t) kst.ksigtramp_end;
|
||
}
|
||
}
|
||
#endif
|
||
}
|