1 /* BSD Kernel Data Access Library (libkvm) interface.
3 Copyright (C) 2004, 2005, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "cli/cli-cmds.h"
28 #include "gdbcore.h" /* for get_exec_file */
29 #include "gdbthread.h"
31 #include "gdb_assert.h"
38 #include "readline/readline.h"
39 #include <sys/param.h>
45 /* Kernel memory device file. */
46 static const char *bsd_kvm_corefile;
48 /* Kernel memory interface descriptor. */
49 static kvm_t *core_kd;
51 /* Address of process control block. */
52 static struct pcb *bsd_kvm_paddr;
54 /* Pointer to architecture-specific function that reconstructs the
55 register state from PCB and supplies it to REGCACHE. */
56 static int (*bsd_kvm_supply_pcb)(struct regcache *regcache, struct pcb *pcb);
58 /* Target ops for libkvm interface. */
59 static struct target_ops bsd_kvm_ops;
61 /* This is the ptid we use while we're connected to kvm. The kvm
62 target currently doesn't export any view of the running processes,
63 so this represents the kernel task. */
64 static ptid_t bsd_kvm_ptid;
67 bsd_kvm_open (char *filename, int from_tty)
69 char errbuf[_POSIX2_LINE_MAX];
70 char *execfile = NULL;
73 target_preopen (from_tty);
79 filename = tilde_expand (filename);
80 if (filename[0] != '/')
82 temp = concat (current_directory, "/", filename, (char *)NULL);
88 execfile = get_exec_file (0);
89 temp_kd = kvm_openfiles (execfile, filename, NULL,
90 write_files ? O_RDWR : O_RDONLY, errbuf);
92 error (("%s"), errbuf);
94 bsd_kvm_corefile = filename;
95 unpush_target (&bsd_kvm_ops);
97 push_target (&bsd_kvm_ops);
99 add_thread_silent (bsd_kvm_ptid);
100 inferior_ptid = bsd_kvm_ptid;
102 target_fetch_registers (get_current_regcache (), -1);
104 reinit_frame_cache ();
105 print_stack_frame (get_selected_frame (NULL), -1, 1);
109 bsd_kvm_close (int quitting)
113 if (kvm_close (core_kd) == -1)
114 warning (("%s"), kvm_geterr(core_kd));
118 inferior_ptid = null_ptid;
119 delete_thread_silent (bsd_kvm_ptid);
123 bsd_kvm_xfer_memory (CORE_ADDR addr, ULONGEST len,
124 gdb_byte *readbuf, const gdb_byte *writebuf)
126 ssize_t nbytes = len;
129 nbytes = kvm_read (core_kd, addr, readbuf, nbytes);
130 if (writebuf && nbytes > 0)
131 nbytes = kvm_write (core_kd, addr, writebuf, nbytes);
136 bsd_kvm_xfer_partial (struct target_ops *ops, enum target_object object,
137 const char *annex, gdb_byte *readbuf,
138 const gdb_byte *writebuf,
139 ULONGEST offset, LONGEST len)
143 case TARGET_OBJECT_MEMORY:
144 return bsd_kvm_xfer_memory (offset, len, readbuf, writebuf);
152 bsd_kvm_files_info (struct target_ops *ops)
154 if (bsd_kvm_corefile && strcmp (bsd_kvm_corefile, _PATH_MEM) != 0)
155 printf_filtered (_("\tUsing the kernel crash dump %s.\n"),
158 printf_filtered (_("\tUsing the currently running kernel.\n"));
161 /* Fetch process control block at address PADDR. */
164 bsd_kvm_fetch_pcb (struct regcache *regcache, struct pcb *paddr)
168 if (kvm_read (core_kd, (unsigned long) paddr, &pcb, sizeof pcb) == -1)
169 error (("%s"), kvm_geterr (core_kd));
171 gdb_assert (bsd_kvm_supply_pcb);
172 return bsd_kvm_supply_pcb (regcache, &pcb);
176 bsd_kvm_fetch_registers (struct target_ops *ops,
177 struct regcache *regcache, int regnum)
183 bsd_kvm_fetch_pcb (regcache, bsd_kvm_paddr);
187 /* On dumping core, BSD kernels store the faulting context (PCB)
188 in the variable "dumppcb". */
189 memset (nl, 0, sizeof nl);
190 nl[0].n_name = "_dumppcb";
192 if (kvm_nlist (core_kd, nl) == -1)
193 error (("%s"), kvm_geterr (core_kd));
195 if (nl[0].n_value != 0)
197 /* Found dumppcb. If it contains a valid context, return
199 if (bsd_kvm_fetch_pcb (regcache, (struct pcb *) nl[0].n_value))
203 /* Traditional BSD kernels have a process proc0 that should always
204 be present. The address of proc0's PCB is stored in the variable
207 memset (nl, 0, sizeof nl);
208 nl[0].n_name = "_proc0paddr";
210 if (kvm_nlist (core_kd, nl) == -1)
211 error (("%s"), kvm_geterr (core_kd));
213 if (nl[0].n_value != 0)
217 /* Found proc0paddr. */
218 if (kvm_read (core_kd, nl[0].n_value, &paddr, sizeof paddr) == -1)
219 error (("%s"), kvm_geterr (core_kd));
221 bsd_kvm_fetch_pcb (regcache, paddr);
225 #ifdef HAVE_STRUCT_THREAD_TD_PCB
226 /* In FreeBSD kernels for 5.0-RELEASE and later, the PCB no longer
227 lives in `struct proc' but in `struct thread'. The `struct
228 thread' for the initial thread for proc0 can be found in the
229 variable "thread0". */
231 memset (nl, 0, sizeof nl);
232 nl[0].n_name = "_thread0";
234 if (kvm_nlist (core_kd, nl) == -1)
235 error (("%s"), kvm_geterr (core_kd));
237 if (nl[0].n_value != 0)
242 nl[0].n_value += offsetof (struct thread, td_pcb);
243 if (kvm_read (core_kd, nl[0].n_value, &paddr, sizeof paddr) == -1)
244 error (("%s"), kvm_geterr (core_kd));
246 bsd_kvm_fetch_pcb (regcache, paddr);
251 /* i18n: PCB == "Process Control Block" */
252 error (_("Cannot find a valid PCB"));
256 /* Kernel memory interface commands. */
257 struct cmd_list_element *bsd_kvm_cmdlist;
260 bsd_kvm_cmd (char *arg, int fromtty)
262 /* ??? Should this become an alias for "target kvm"? */
265 #ifndef HAVE_STRUCT_THREAD_TD_PCB
268 bsd_kvm_proc_cmd (char *arg, int fromtty)
273 error_no_arg (_("proc address"));
276 error (_("No kernel memory image."));
278 addr = parse_and_eval_address (arg);
279 #ifdef HAVE_STRUCT_LWP
280 addr += offsetof (struct lwp, l_addr);
282 addr += offsetof (struct proc, p_addr);
285 if (kvm_read (core_kd, addr, &bsd_kvm_paddr, sizeof bsd_kvm_paddr) == -1)
286 error (("%s"), kvm_geterr (core_kd));
288 target_fetch_registers (get_current_regcache (), -1);
290 reinit_frame_cache ();
291 print_stack_frame (get_selected_frame (NULL), -1, 1);
297 bsd_kvm_pcb_cmd (char *arg, int fromtty)
300 /* i18n: PCB == "Process Control Block" */
301 error_no_arg (_("pcb address"));
304 error (_("No kernel memory image."));
306 bsd_kvm_paddr = (struct pcb *)(u_long) parse_and_eval_address (arg);
308 target_fetch_registers (get_current_regcache (), -1);
310 reinit_frame_cache ();
311 print_stack_frame (get_selected_frame (NULL), -1, 1);
315 bsd_kvm_thread_alive (struct target_ops *ops,
322 bsd_kvm_pid_to_str (struct target_ops *ops, ptid_t ptid)
325 xsnprintf (buf, sizeof buf, "<kvm>");
330 bsd_kvm_return_one (struct target_ops *ops)
335 /* Add the libkvm interface to the list of all possible targets and
336 register CUPPLY_PCB as the architecture-specific process control
337 block interpreter. */
340 bsd_kvm_add_target (int (*supply_pcb)(struct regcache *, struct pcb *))
342 gdb_assert (bsd_kvm_supply_pcb == NULL);
343 bsd_kvm_supply_pcb = supply_pcb;
345 bsd_kvm_ops.to_shortname = "kvm";
346 bsd_kvm_ops.to_longname = _("Kernel memory interface");
347 bsd_kvm_ops.to_doc = _("Use a kernel virtual memory image as a target.\n\
348 Optionally specify the filename of a core dump.");
349 bsd_kvm_ops.to_open = bsd_kvm_open;
350 bsd_kvm_ops.to_close = bsd_kvm_close;
351 bsd_kvm_ops.to_fetch_registers = bsd_kvm_fetch_registers;
352 bsd_kvm_ops.to_xfer_partial = bsd_kvm_xfer_partial;
353 bsd_kvm_ops.to_files_info = bsd_kvm_files_info;
354 bsd_kvm_ops.to_thread_alive = bsd_kvm_thread_alive;
355 bsd_kvm_ops.to_pid_to_str = bsd_kvm_pid_to_str;
356 bsd_kvm_ops.to_stratum = process_stratum;
357 bsd_kvm_ops.to_has_memory = bsd_kvm_return_one;
358 bsd_kvm_ops.to_has_stack = bsd_kvm_return_one;
359 bsd_kvm_ops.to_has_registers = bsd_kvm_return_one;
360 bsd_kvm_ops.to_magic = OPS_MAGIC;
362 add_target (&bsd_kvm_ops);
364 add_prefix_cmd ("kvm", class_obscure, bsd_kvm_cmd, _("\
365 Generic command for manipulating the kernel memory interface."),
366 &bsd_kvm_cmdlist, "kvm ", 0, &cmdlist);
368 #ifndef HAVE_STRUCT_THREAD_TD_PCB
369 add_cmd ("proc", class_obscure, bsd_kvm_proc_cmd,
370 _("Set current context from proc address"), &bsd_kvm_cmdlist);
372 add_cmd ("pcb", class_obscure, bsd_kvm_pcb_cmd,
373 /* i18n: PCB == "Process Control Block" */
374 _("Set current context from pcb address"), &bsd_kvm_cmdlist);
376 /* Some notes on the ptid usage on this target.
378 The pid field represents the kvm inferior instance. Currently,
379 we don't support multiple kvm inferiors, but we start at 1
380 anyway. The lwp field is set to != 0, in case the core wants to
381 refer to the whole kvm inferior with ptid(1,0,0).
383 If kvm is made to export running processes as gdb threads,
384 the following form can be used:
385 ptid (1, 1, 0) -> kvm inferior 1, in kernel
386 ptid (1, 1, 1) -> kvm inferior 1, process 1
387 ptid (1, 1, 2) -> kvm inferior 1, process 2
388 ptid (1, 1, n) -> kvm inferior 1, process n
390 bsd_kvm_ptid = ptid_build (1, 1, 0);