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/* BSD Kernel Data Access Library (libkvm) interface.
Copyright 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., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "frame.h"
#include "regcache.h"
#include "target.h"
#include "gdb_assert.h"
#include <fcntl.h>
#include <kvm.h>
#include <nlist.h>
#include "readline/readline.h"
#include <sys/param.h>
#include <sys/user.h>
#include "bsd-kvm.h"
/* Kernel memory interface descriptor. */
kvm_t *core_kd;
/* Address of process control block. */
struct pcb *bsd_kvm_paddr;
/* Pointer to architecture-specific function that reconstructs the
register state from PCB and supplies it to REGCACHE. */
int (*bsd_kvm_supply_pcb)(struct regcache *regcache, struct pcb *pcb);
/* Target ops for libkvm interface. */
struct target_ops bsd_kvm_ops;
static void
bsd_kvm_open (char *filename, int from_tty)
{
char errbuf[_POSIX2_LINE_MAX];
char *execfile = NULL;
kvm_t *temp_kd;
target_preopen (from_tty);
if (filename)
{
char *temp;
filename = tilde_expand (filename);
if (filename[0] != '/')
{
temp = concat (current_directory, "/", filename, NULL);
xfree (filename);
filename = temp;
}
}
temp_kd = kvm_openfiles (execfile, filename, NULL, O_RDONLY, errbuf);
if (temp_kd == NULL)
error ("%s", errbuf);
unpush_target (&bsd_kvm_ops);
core_kd = temp_kd;
push_target (&bsd_kvm_ops);
target_fetch_registers (-1);
flush_cached_frames ();
select_frame (get_current_frame ());
print_stack_frame (get_selected_frame (), -1, 1);
}
static void
bsd_kvm_close (int quitting)
{
if (core_kd)
{
if (kvm_close (core_kd) == -1)
warning ("%s", kvm_geterr(core_kd));
core_kd = NULL;
}
}
static int
bsd_kvm_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len,
int write, struct mem_attrib *attrib,
struct target_ops *ops)
{
if (write)
return kvm_write (core_kd, memaddr, myaddr, len);
else
return kvm_read (core_kd, memaddr, myaddr, len);
return -1;
}
/* Fetch process control block at address PADDR. */
static int
bsd_kvm_fetch_pcb (struct pcb *paddr)
{
struct pcb pcb;
if (kvm_read (core_kd, (unsigned long) paddr, &pcb, sizeof pcb) == -1)
error ("%s", kvm_geterr (core_kd));
gdb_assert (bsd_kvm_supply_pcb);
return bsd_kvm_supply_pcb (current_regcache, &pcb);
}
static void
bsd_kvm_fetch_registers (int regnum)
{
struct nlist nl[2];
if (bsd_kvm_paddr)
{
bsd_kvm_fetch_pcb (bsd_kvm_paddr);
return;
}
/* On dumping core, BSD kernels store the faulting context (PCB)
in the variable "dumppcb". */
memset (nl, 0, sizeof nl);
nl[0].n_name = "_dumppcb";
if (kvm_nlist (core_kd, nl) == -1)
error ("%s", kvm_geterr (core_kd));
if (nl[0].n_value != 0)
{
/* Found dumppcb. If it contains a valid context, return
immediately. */
if (bsd_kvm_fetch_pcb ((struct pcb *) nl[0].n_value))
return;
}
/* Traditional BSD kernels have a process proc0 that should always
be present. The address of proc0's PCB is stored in the variable
"proc0paddr". */
memset (nl, 0, sizeof nl);
nl[0].n_name = "_proc0paddr";
if (kvm_nlist (core_kd, nl) == -1)
error ("%s", kvm_geterr (core_kd));
if (nl[0].n_value != 0)
{
struct pcb *paddr;
/* Found proc0paddr. */
if (kvm_read (core_kd, nl[0].n_value, &paddr, sizeof paddr) == -1)
error ("%s", kvm_geterr (core_kd));
bsd_kvm_fetch_pcb (paddr);
return;
}
#ifdef HAVE_STRUCT_THREAD_TD_PCB
/* In FreeBSD kernels for 5.0-RELEASE and later, the PCB no longer
lives in `struct proc' but in `struct thread'. The `struct
thread' for the initial thread for proc0 can be found in the
variable "thread0". */
memset (nl, 0, sizeof nl);
nl[0].n_name = "_thread0";
if (kvm_nlist (core_kd, nl) == -1)
error ("%s", kvm_geterr (core_kd));
if (nl[0].n_value != 0)
{
struct pcb *paddr;
/* Found thread0. */
nl[0].n_value += offsetof (struct thread, td_pcb);
if (kvm_read (core_kd, nl[0].n_value, &paddr, sizeof paddr) == -1)
error ("%s", kvm_geterr (core_kd));
bsd_kvm_fetch_pcb (paddr);
return;
}
#endif
error ("Cannot find a valid PCB");
}
/* Add the libkvm interface to the list of all possible targets and
register CUPPLY_PCB as the architecture-specific process control
block interpreter. */
void
bsd_kvm_add_target (int (*supply_pcb)(struct regcache *, struct pcb *))
{
gdb_assert (bsd_kvm_supply_pcb == NULL);
bsd_kvm_supply_pcb = supply_pcb;
bsd_kvm_ops.to_shortname = "kvm";
bsd_kvm_ops.to_longname = "Kernel memory interface";
bsd_kvm_ops.to_doc = "Use a kernel virtual memory image as a target.\n\
Optionally specify the filename of a core dump.";
bsd_kvm_ops.to_open = bsd_kvm_open;
bsd_kvm_ops.to_close = bsd_kvm_close;
bsd_kvm_ops.to_fetch_registers = bsd_kvm_fetch_registers;
bsd_kvm_ops.to_xfer_memory = bsd_kvm_xfer_memory;
bsd_kvm_ops.to_stratum = process_stratum;
bsd_kvm_ops.to_has_memory = 1;
bsd_kvm_ops.to_has_stack = 1;
bsd_kvm_ops.to_has_registers = 1;
bsd_kvm_ops.to_magic = OPS_MAGIC;
add_target (&bsd_kvm_ops);
}
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