Commit | Line | Data |
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2e0c3539 MK |
1 | /* BSD Kernel Data Access Library (libkvm) interface. |
2 | ||
ecd75fc8 | 3 | Copyright (C) 2004-2014 Free Software Foundation, Inc. |
2e0c3539 MK |
4 | |
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
2e0c3539 MK |
10 | (at your option) any later version. |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
2e0c3539 MK |
19 | |
20 | #include "defs.h" | |
963c4174 MK |
21 | #include "cli/cli-cmds.h" |
22 | #include "command.h" | |
2e0c3539 MK |
23 | #include "frame.h" |
24 | #include "regcache.h" | |
25 | #include "target.h" | |
963c4174 | 26 | #include "value.h" |
7f245d65 | 27 | #include "gdbcore.h" /* for get_exec_file */ |
6c613132 | 28 | #include "gdbthread.h" |
2e0c3539 MK |
29 | |
30 | #include "gdb_assert.h" | |
31 | #include <fcntl.h> | |
32 | #include <kvm.h> | |
ac5754fa | 33 | #ifdef HAVE_NLIST_H |
2e0c3539 | 34 | #include <nlist.h> |
ac5754fa | 35 | #endif |
2e5a5020 | 36 | #include <paths.h> |
2e0c3539 | 37 | #include "readline/readline.h" |
af09351e | 38 | #include <sys/param.h> |
963c4174 | 39 | #include <sys/proc.h> |
2e0c3539 MK |
40 | #include <sys/user.h> |
41 | ||
42 | #include "bsd-kvm.h" | |
43 | ||
2e5a5020 MK |
44 | /* Kernel memory device file. */ |
45 | static const char *bsd_kvm_corefile; | |
46 | ||
2e0c3539 | 47 | /* Kernel memory interface descriptor. */ |
2e5a5020 | 48 | static kvm_t *core_kd; |
2e0c3539 MK |
49 | |
50 | /* Address of process control block. */ | |
2e5a5020 | 51 | static struct pcb *bsd_kvm_paddr; |
2e0c3539 MK |
52 | |
53 | /* Pointer to architecture-specific function that reconstructs the | |
54 | register state from PCB and supplies it to REGCACHE. */ | |
2e5a5020 | 55 | static int (*bsd_kvm_supply_pcb)(struct regcache *regcache, struct pcb *pcb); |
2e0c3539 MK |
56 | |
57 | /* Target ops for libkvm interface. */ | |
2e5a5020 | 58 | static struct target_ops bsd_kvm_ops; |
2e0c3539 | 59 | |
6c613132 PA |
60 | /* This is the ptid we use while we're connected to kvm. The kvm |
61 | target currently doesn't export any view of the running processes, | |
62 | so this represents the kernel task. */ | |
63 | static ptid_t bsd_kvm_ptid; | |
64 | ||
2e0c3539 | 65 | static void |
014f9477 | 66 | bsd_kvm_open (const char *arg, int from_tty) |
2e0c3539 MK |
67 | { |
68 | char errbuf[_POSIX2_LINE_MAX]; | |
69 | char *execfile = NULL; | |
70 | kvm_t *temp_kd; | |
014f9477 | 71 | char *filename = NULL; |
2e0c3539 MK |
72 | |
73 | target_preopen (from_tty); | |
74 | ||
014f9477 | 75 | if (arg) |
2e0c3539 MK |
76 | { |
77 | char *temp; | |
78 | ||
014f9477 | 79 | filename = tilde_expand (arg); |
2e0c3539 MK |
80 | if (filename[0] != '/') |
81 | { | |
1754f103 | 82 | temp = concat (current_directory, "/", filename, (char *)NULL); |
2e0c3539 MK |
83 | xfree (filename); |
84 | filename = temp; | |
85 | } | |
86 | } | |
87 | ||
7f245d65 | 88 | execfile = get_exec_file (0); |
4a35b02a NW |
89 | temp_kd = kvm_openfiles (execfile, filename, NULL, |
90 | write_files ? O_RDWR : O_RDONLY, errbuf); | |
2e0c3539 | 91 | if (temp_kd == NULL) |
8a3fe4f8 | 92 | error (("%s"), errbuf); |
2e0c3539 | 93 | |
2e5a5020 | 94 | bsd_kvm_corefile = filename; |
2e0c3539 MK |
95 | unpush_target (&bsd_kvm_ops); |
96 | core_kd = temp_kd; | |
97 | push_target (&bsd_kvm_ops); | |
98 | ||
6c613132 PA |
99 | add_thread_silent (bsd_kvm_ptid); |
100 | inferior_ptid = bsd_kvm_ptid; | |
101 | ||
594f7785 | 102 | target_fetch_registers (get_current_regcache (), -1); |
2e0c3539 | 103 | |
35f196d9 | 104 | reinit_frame_cache (); |
08d72866 | 105 | print_stack_frame (get_selected_frame (NULL), 0, SRC_AND_LOC, 1); |
2e0c3539 MK |
106 | } |
107 | ||
108 | static void | |
de90e03d | 109 | bsd_kvm_close (struct target_ops *self) |
2e0c3539 MK |
110 | { |
111 | if (core_kd) | |
112 | { | |
113 | if (kvm_close (core_kd) == -1) | |
8a3fe4f8 | 114 | warning (("%s"), kvm_geterr(core_kd)); |
2e0c3539 MK |
115 | core_kd = NULL; |
116 | } | |
6c613132 PA |
117 | |
118 | inferior_ptid = null_ptid; | |
119 | delete_thread_silent (bsd_kvm_ptid); | |
2e0c3539 MK |
120 | } |
121 | ||
961cb7b5 MK |
122 | static LONGEST |
123 | bsd_kvm_xfer_memory (CORE_ADDR addr, ULONGEST len, | |
124 | gdb_byte *readbuf, const gdb_byte *writebuf) | |
2e0c3539 | 125 | { |
961cb7b5 MK |
126 | ssize_t nbytes = len; |
127 | ||
128 | if (readbuf) | |
129 | nbytes = kvm_read (core_kd, addr, readbuf, nbytes); | |
130 | if (writebuf && nbytes > 0) | |
131 | nbytes = kvm_write (core_kd, addr, writebuf, nbytes); | |
132 | return nbytes; | |
133 | } | |
2e0c3539 | 134 | |
9b409511 | 135 | static enum target_xfer_status |
961cb7b5 MK |
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, | |
9b409511 | 139 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
961cb7b5 MK |
140 | { |
141 | switch (object) | |
142 | { | |
143 | case TARGET_OBJECT_MEMORY: | |
9b409511 YQ |
144 | { |
145 | LONGEST ret = bsd_kvm_xfer_memory (offset, len, readbuf, writebuf); | |
146 | ||
147 | if (ret < 0) | |
148 | return TARGET_XFER_E_IO; | |
149 | else if (ret == 0) | |
150 | return TARGET_XFER_EOF; | |
151 | else | |
152 | { | |
153 | *xfered_len = (ULONGEST) ret; | |
154 | return TARGET_XFER_OK; | |
155 | } | |
156 | } | |
961cb7b5 MK |
157 | |
158 | default: | |
2ed4b548 | 159 | return TARGET_XFER_E_IO; |
961cb7b5 | 160 | } |
2e0c3539 MK |
161 | } |
162 | ||
2e5a5020 MK |
163 | static void |
164 | bsd_kvm_files_info (struct target_ops *ops) | |
165 | { | |
166 | if (bsd_kvm_corefile && strcmp (bsd_kvm_corefile, _PATH_MEM) != 0) | |
167 | printf_filtered (_("\tUsing the kernel crash dump %s.\n"), | |
168 | bsd_kvm_corefile); | |
169 | else | |
170 | printf_filtered (_("\tUsing the currently running kernel.\n")); | |
171 | } | |
172 | ||
2e0c3539 MK |
173 | /* Fetch process control block at address PADDR. */ |
174 | ||
175 | static int | |
56be3814 | 176 | bsd_kvm_fetch_pcb (struct regcache *regcache, struct pcb *paddr) |
2e0c3539 MK |
177 | { |
178 | struct pcb pcb; | |
179 | ||
180 | if (kvm_read (core_kd, (unsigned long) paddr, &pcb, sizeof pcb) == -1) | |
8a3fe4f8 | 181 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 MK |
182 | |
183 | gdb_assert (bsd_kvm_supply_pcb); | |
56be3814 | 184 | return bsd_kvm_supply_pcb (regcache, &pcb); |
2e0c3539 MK |
185 | } |
186 | ||
187 | static void | |
28439f5e PA |
188 | bsd_kvm_fetch_registers (struct target_ops *ops, |
189 | struct regcache *regcache, int regnum) | |
2e0c3539 MK |
190 | { |
191 | struct nlist nl[2]; | |
192 | ||
193 | if (bsd_kvm_paddr) | |
efe1d7b9 | 194 | { |
56be3814 | 195 | bsd_kvm_fetch_pcb (regcache, bsd_kvm_paddr); |
efe1d7b9 MK |
196 | return; |
197 | } | |
2e0c3539 MK |
198 | |
199 | /* On dumping core, BSD kernels store the faulting context (PCB) | |
200 | in the variable "dumppcb". */ | |
201 | memset (nl, 0, sizeof nl); | |
202 | nl[0].n_name = "_dumppcb"; | |
203 | ||
204 | if (kvm_nlist (core_kd, nl) == -1) | |
8a3fe4f8 | 205 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 MK |
206 | |
207 | if (nl[0].n_value != 0) | |
208 | { | |
4a64f543 | 209 | /* Found dumppcb. If it contains a valid context, return |
2e0c3539 | 210 | immediately. */ |
56be3814 | 211 | if (bsd_kvm_fetch_pcb (regcache, (struct pcb *) nl[0].n_value)) |
2e0c3539 MK |
212 | return; |
213 | } | |
214 | ||
215 | /* Traditional BSD kernels have a process proc0 that should always | |
216 | be present. The address of proc0's PCB is stored in the variable | |
217 | "proc0paddr". */ | |
218 | ||
219 | memset (nl, 0, sizeof nl); | |
220 | nl[0].n_name = "_proc0paddr"; | |
221 | ||
222 | if (kvm_nlist (core_kd, nl) == -1) | |
8a3fe4f8 | 223 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 MK |
224 | |
225 | if (nl[0].n_value != 0) | |
226 | { | |
227 | struct pcb *paddr; | |
228 | ||
229 | /* Found proc0paddr. */ | |
230 | if (kvm_read (core_kd, nl[0].n_value, &paddr, sizeof paddr) == -1) | |
8a3fe4f8 | 231 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 | 232 | |
56be3814 | 233 | bsd_kvm_fetch_pcb (regcache, paddr); |
2e0c3539 MK |
234 | return; |
235 | } | |
236 | ||
237 | #ifdef HAVE_STRUCT_THREAD_TD_PCB | |
238 | /* In FreeBSD kernels for 5.0-RELEASE and later, the PCB no longer | |
239 | lives in `struct proc' but in `struct thread'. The `struct | |
240 | thread' for the initial thread for proc0 can be found in the | |
241 | variable "thread0". */ | |
242 | ||
243 | memset (nl, 0, sizeof nl); | |
244 | nl[0].n_name = "_thread0"; | |
245 | ||
246 | if (kvm_nlist (core_kd, nl) == -1) | |
8a3fe4f8 | 247 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 MK |
248 | |
249 | if (nl[0].n_value != 0) | |
250 | { | |
251 | struct pcb *paddr; | |
252 | ||
253 | /* Found thread0. */ | |
efe1d7b9 MK |
254 | nl[0].n_value += offsetof (struct thread, td_pcb); |
255 | if (kvm_read (core_kd, nl[0].n_value, &paddr, sizeof paddr) == -1) | |
8a3fe4f8 | 256 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 | 257 | |
56be3814 | 258 | bsd_kvm_fetch_pcb (regcache, paddr); |
2e0c3539 MK |
259 | return; |
260 | } | |
261 | #endif | |
262 | ||
0963b4bd | 263 | /* i18n: PCB == "Process Control Block". */ |
3d263c1d | 264 | error (_("Cannot find a valid PCB")); |
2e0c3539 MK |
265 | } |
266 | \f | |
267 | ||
963c4174 | 268 | /* Kernel memory interface commands. */ |
fdb1bf9d | 269 | struct cmd_list_element *bsd_kvm_cmdlist; |
963c4174 MK |
270 | |
271 | static void | |
272 | bsd_kvm_cmd (char *arg, int fromtty) | |
273 | { | |
274 | /* ??? Should this become an alias for "target kvm"? */ | |
275 | } | |
276 | ||
277 | #ifndef HAVE_STRUCT_THREAD_TD_PCB | |
278 | ||
279 | static void | |
280 | bsd_kvm_proc_cmd (char *arg, int fromtty) | |
281 | { | |
282 | CORE_ADDR addr; | |
283 | ||
284 | if (arg == NULL) | |
3d263c1d | 285 | error_no_arg (_("proc address")); |
963c4174 MK |
286 | |
287 | if (core_kd == NULL) | |
3d263c1d | 288 | error (_("No kernel memory image.")); |
963c4174 MK |
289 | |
290 | addr = parse_and_eval_address (arg); | |
da7d81e3 NW |
291 | #ifdef HAVE_STRUCT_LWP |
292 | addr += offsetof (struct lwp, l_addr); | |
293 | #else | |
963c4174 | 294 | addr += offsetof (struct proc, p_addr); |
da7d81e3 | 295 | #endif |
963c4174 MK |
296 | |
297 | if (kvm_read (core_kd, addr, &bsd_kvm_paddr, sizeof bsd_kvm_paddr) == -1) | |
8a3fe4f8 | 298 | error (("%s"), kvm_geterr (core_kd)); |
963c4174 | 299 | |
594f7785 | 300 | target_fetch_registers (get_current_regcache (), -1); |
963c4174 | 301 | |
35f196d9 | 302 | reinit_frame_cache (); |
08d72866 | 303 | print_stack_frame (get_selected_frame (NULL), 0, SRC_AND_LOC, 1); |
963c4174 MK |
304 | } |
305 | ||
306 | #endif | |
307 | ||
308 | static void | |
309 | bsd_kvm_pcb_cmd (char *arg, int fromtty) | |
310 | { | |
311 | if (arg == NULL) | |
0963b4bd | 312 | /* i18n: PCB == "Process Control Block". */ |
3d263c1d | 313 | error_no_arg (_("pcb address")); |
963c4174 MK |
314 | |
315 | if (core_kd == NULL) | |
3d263c1d | 316 | error (_("No kernel memory image.")); |
963c4174 | 317 | |
57ac95b8 | 318 | bsd_kvm_paddr = (struct pcb *)(u_long) parse_and_eval_address (arg); |
963c4174 | 319 | |
594f7785 | 320 | target_fetch_registers (get_current_regcache (), -1); |
963c4174 | 321 | |
35f196d9 | 322 | reinit_frame_cache (); |
08d72866 | 323 | print_stack_frame (get_selected_frame (NULL), 0, SRC_AND_LOC, 1); |
963c4174 MK |
324 | } |
325 | ||
6c613132 | 326 | static int |
28439f5e PA |
327 | bsd_kvm_thread_alive (struct target_ops *ops, |
328 | ptid_t ptid) | |
6c613132 PA |
329 | { |
330 | return 1; | |
331 | } | |
332 | ||
333 | static char * | |
117de6a9 | 334 | bsd_kvm_pid_to_str (struct target_ops *ops, ptid_t ptid) |
6c613132 PA |
335 | { |
336 | static char buf[64]; | |
337 | xsnprintf (buf, sizeof buf, "<kvm>"); | |
338 | return buf; | |
339 | } | |
340 | ||
c35b1492 PA |
341 | static int |
342 | bsd_kvm_return_one (struct target_ops *ops) | |
343 | { | |
344 | return 1; | |
345 | } | |
346 | ||
2e0c3539 MK |
347 | /* Add the libkvm interface to the list of all possible targets and |
348 | register CUPPLY_PCB as the architecture-specific process control | |
349 | block interpreter. */ | |
350 | ||
351 | void | |
352 | bsd_kvm_add_target (int (*supply_pcb)(struct regcache *, struct pcb *)) | |
353 | { | |
354 | gdb_assert (bsd_kvm_supply_pcb == NULL); | |
355 | bsd_kvm_supply_pcb = supply_pcb; | |
356 | ||
357 | bsd_kvm_ops.to_shortname = "kvm"; | |
3d263c1d BI |
358 | bsd_kvm_ops.to_longname = _("Kernel memory interface"); |
359 | bsd_kvm_ops.to_doc = _("Use a kernel virtual memory image as a target.\n\ | |
360 | Optionally specify the filename of a core dump."); | |
2e0c3539 MK |
361 | bsd_kvm_ops.to_open = bsd_kvm_open; |
362 | bsd_kvm_ops.to_close = bsd_kvm_close; | |
363 | bsd_kvm_ops.to_fetch_registers = bsd_kvm_fetch_registers; | |
961cb7b5 | 364 | bsd_kvm_ops.to_xfer_partial = bsd_kvm_xfer_partial; |
2e5a5020 | 365 | bsd_kvm_ops.to_files_info = bsd_kvm_files_info; |
6c613132 PA |
366 | bsd_kvm_ops.to_thread_alive = bsd_kvm_thread_alive; |
367 | bsd_kvm_ops.to_pid_to_str = bsd_kvm_pid_to_str; | |
2e0c3539 | 368 | bsd_kvm_ops.to_stratum = process_stratum; |
c35b1492 PA |
369 | bsd_kvm_ops.to_has_memory = bsd_kvm_return_one; |
370 | bsd_kvm_ops.to_has_stack = bsd_kvm_return_one; | |
371 | bsd_kvm_ops.to_has_registers = bsd_kvm_return_one; | |
2e0c3539 MK |
372 | bsd_kvm_ops.to_magic = OPS_MAGIC; |
373 | ||
374 | add_target (&bsd_kvm_ops); | |
963c4174 | 375 | |
3d263c1d BI |
376 | add_prefix_cmd ("kvm", class_obscure, bsd_kvm_cmd, _("\ |
377 | Generic command for manipulating the kernel memory interface."), | |
963c4174 MK |
378 | &bsd_kvm_cmdlist, "kvm ", 0, &cmdlist); |
379 | ||
380 | #ifndef HAVE_STRUCT_THREAD_TD_PCB | |
381 | add_cmd ("proc", class_obscure, bsd_kvm_proc_cmd, | |
3d263c1d | 382 | _("Set current context from proc address"), &bsd_kvm_cmdlist); |
963c4174 MK |
383 | #endif |
384 | add_cmd ("pcb", class_obscure, bsd_kvm_pcb_cmd, | |
0963b4bd | 385 | /* i18n: PCB == "Process Control Block". */ |
3d263c1d | 386 | _("Set current context from pcb address"), &bsd_kvm_cmdlist); |
6c613132 PA |
387 | |
388 | /* Some notes on the ptid usage on this target. | |
389 | ||
390 | The pid field represents the kvm inferior instance. Currently, | |
391 | we don't support multiple kvm inferiors, but we start at 1 | |
392 | anyway. The lwp field is set to != 0, in case the core wants to | |
393 | refer to the whole kvm inferior with ptid(1,0,0). | |
394 | ||
395 | If kvm is made to export running processes as gdb threads, | |
396 | the following form can be used: | |
397 | ptid (1, 1, 0) -> kvm inferior 1, in kernel | |
398 | ptid (1, 1, 1) -> kvm inferior 1, process 1 | |
399 | ptid (1, 1, 2) -> kvm inferior 1, process 2 | |
0963b4bd MS |
400 | ptid (1, 1, n) -> kvm inferior 1, process n */ |
401 | ||
6c613132 | 402 | bsd_kvm_ptid = ptid_build (1, 1, 0); |
2e0c3539 | 403 | } |