* bsd-kvm.c, bsd-kvm.h: New files.

* i386fbsd-nat.c: Include <sys/types.h>, <machine/pcb.h> and
"bsd-kvm.h".
(i386fbsd_supply_pcb): New function.
* Makefile.in (ALLDEPFILES): Add bsd-kvm.c.
(i386fbsd-nat.o): Update dependencies.
(bsd_kvm_h): New variable.
(bsd-kvm.o): New dependency.
* config/i386/fbsd.mh (NATDEPFILES): Add bsd-kvm.o.
(LOADLIBES): New variable.

1 files changed, 226 insertions, 0 deletions

diff --git a/gdb/bsd-kvm.c b/gdb/bsd-kvm.c
new file mode 100644
index 00000000000..37fc2b48a6a
--- /dev/null
+++ b/gdb/bsd-kvm.c
@@ -0,0 +1,226 @@
+/* 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);
+
+  /* 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[1].n_value += offsetof (struct thread, td_pcb);
+      if (kvm_read (core_kd, nl[1].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);
+}