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2e0c3539 MK |
1 | /* BSD Kernel Data Access Library (libkvm) interface. |
2 | ||
9b254dd1 | 3 | Copyright (C) 2004, 2005, 2007, 2008 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 MK |
37 | #include "readline/readline.h" |
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 MK |
65 | static void |
66 | bsd_kvm_open (char *filename, int from_tty) | |
67 | { | |
68 | char errbuf[_POSIX2_LINE_MAX]; | |
69 | char *execfile = NULL; | |
70 | kvm_t *temp_kd; | |
71 | ||
72 | target_preopen (from_tty); | |
73 | ||
74 | if (filename) | |
75 | { | |
76 | char *temp; | |
77 | ||
78 | filename = tilde_expand (filename); | |
79 | if (filename[0] != '/') | |
80 | { | |
1754f103 | 81 | temp = concat (current_directory, "/", filename, (char *)NULL); |
2e0c3539 MK |
82 | xfree (filename); |
83 | filename = temp; | |
84 | } | |
85 | } | |
86 | ||
7f245d65 | 87 | execfile = get_exec_file (0); |
4a35b02a NW |
88 | temp_kd = kvm_openfiles (execfile, filename, NULL, |
89 | write_files ? O_RDWR : O_RDONLY, errbuf); | |
2e0c3539 | 90 | if (temp_kd == NULL) |
8a3fe4f8 | 91 | error (("%s"), errbuf); |
2e0c3539 | 92 | |
2e5a5020 | 93 | bsd_kvm_corefile = filename; |
2e0c3539 MK |
94 | unpush_target (&bsd_kvm_ops); |
95 | core_kd = temp_kd; | |
96 | push_target (&bsd_kvm_ops); | |
97 | ||
6c613132 PA |
98 | add_thread_silent (bsd_kvm_ptid); |
99 | inferior_ptid = bsd_kvm_ptid; | |
100 | ||
594f7785 | 101 | target_fetch_registers (get_current_regcache (), -1); |
2e0c3539 | 102 | |
35f196d9 | 103 | reinit_frame_cache (); |
b04f3ab4 | 104 | print_stack_frame (get_selected_frame (NULL), -1, 1); |
2e0c3539 MK |
105 | } |
106 | ||
107 | static void | |
108 | bsd_kvm_close (int quitting) | |
109 | { | |
110 | if (core_kd) | |
111 | { | |
112 | if (kvm_close (core_kd) == -1) | |
8a3fe4f8 | 113 | warning (("%s"), kvm_geterr(core_kd)); |
2e0c3539 MK |
114 | core_kd = NULL; |
115 | } | |
6c613132 PA |
116 | |
117 | inferior_ptid = null_ptid; | |
118 | delete_thread_silent (bsd_kvm_ptid); | |
2e0c3539 MK |
119 | } |
120 | ||
961cb7b5 MK |
121 | static LONGEST |
122 | bsd_kvm_xfer_memory (CORE_ADDR addr, ULONGEST len, | |
123 | gdb_byte *readbuf, const gdb_byte *writebuf) | |
2e0c3539 | 124 | { |
961cb7b5 MK |
125 | ssize_t nbytes = len; |
126 | ||
127 | if (readbuf) | |
128 | nbytes = kvm_read (core_kd, addr, readbuf, nbytes); | |
129 | if (writebuf && nbytes > 0) | |
130 | nbytes = kvm_write (core_kd, addr, writebuf, nbytes); | |
131 | return nbytes; | |
132 | } | |
2e0c3539 | 133 | |
961cb7b5 MK |
134 | static LONGEST |
135 | bsd_kvm_xfer_partial (struct target_ops *ops, enum target_object object, | |
136 | const char *annex, gdb_byte *readbuf, | |
137 | const gdb_byte *writebuf, | |
138 | ULONGEST offset, LONGEST len) | |
139 | { | |
140 | switch (object) | |
141 | { | |
142 | case TARGET_OBJECT_MEMORY: | |
143 | return bsd_kvm_xfer_memory (offset, len, readbuf, writebuf); | |
144 | ||
145 | default: | |
146 | return -1; | |
147 | } | |
2e0c3539 MK |
148 | } |
149 | ||
2e5a5020 MK |
150 | static void |
151 | bsd_kvm_files_info (struct target_ops *ops) | |
152 | { | |
153 | if (bsd_kvm_corefile && strcmp (bsd_kvm_corefile, _PATH_MEM) != 0) | |
154 | printf_filtered (_("\tUsing the kernel crash dump %s.\n"), | |
155 | bsd_kvm_corefile); | |
156 | else | |
157 | printf_filtered (_("\tUsing the currently running kernel.\n")); | |
158 | } | |
159 | ||
2e0c3539 MK |
160 | /* Fetch process control block at address PADDR. */ |
161 | ||
162 | static int | |
56be3814 | 163 | bsd_kvm_fetch_pcb (struct regcache *regcache, struct pcb *paddr) |
2e0c3539 MK |
164 | { |
165 | struct pcb pcb; | |
166 | ||
167 | if (kvm_read (core_kd, (unsigned long) paddr, &pcb, sizeof pcb) == -1) | |
8a3fe4f8 | 168 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 MK |
169 | |
170 | gdb_assert (bsd_kvm_supply_pcb); | |
56be3814 | 171 | return bsd_kvm_supply_pcb (regcache, &pcb); |
2e0c3539 MK |
172 | } |
173 | ||
174 | static void | |
56be3814 | 175 | bsd_kvm_fetch_registers (struct regcache *regcache, int regnum) |
2e0c3539 MK |
176 | { |
177 | struct nlist nl[2]; | |
178 | ||
179 | if (bsd_kvm_paddr) | |
efe1d7b9 | 180 | { |
56be3814 | 181 | bsd_kvm_fetch_pcb (regcache, bsd_kvm_paddr); |
efe1d7b9 MK |
182 | return; |
183 | } | |
2e0c3539 MK |
184 | |
185 | /* On dumping core, BSD kernels store the faulting context (PCB) | |
186 | in the variable "dumppcb". */ | |
187 | memset (nl, 0, sizeof nl); | |
188 | nl[0].n_name = "_dumppcb"; | |
189 | ||
190 | if (kvm_nlist (core_kd, nl) == -1) | |
8a3fe4f8 | 191 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 MK |
192 | |
193 | if (nl[0].n_value != 0) | |
194 | { | |
195 | /* Found dumppcb. If it contains a valid context, return | |
196 | immediately. */ | |
56be3814 | 197 | if (bsd_kvm_fetch_pcb (regcache, (struct pcb *) nl[0].n_value)) |
2e0c3539 MK |
198 | return; |
199 | } | |
200 | ||
201 | /* Traditional BSD kernels have a process proc0 that should always | |
202 | be present. The address of proc0's PCB is stored in the variable | |
203 | "proc0paddr". */ | |
204 | ||
205 | memset (nl, 0, sizeof nl); | |
206 | nl[0].n_name = "_proc0paddr"; | |
207 | ||
208 | if (kvm_nlist (core_kd, nl) == -1) | |
8a3fe4f8 | 209 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 MK |
210 | |
211 | if (nl[0].n_value != 0) | |
212 | { | |
213 | struct pcb *paddr; | |
214 | ||
215 | /* Found proc0paddr. */ | |
216 | if (kvm_read (core_kd, nl[0].n_value, &paddr, sizeof paddr) == -1) | |
8a3fe4f8 | 217 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 | 218 | |
56be3814 | 219 | bsd_kvm_fetch_pcb (regcache, paddr); |
2e0c3539 MK |
220 | return; |
221 | } | |
222 | ||
223 | #ifdef HAVE_STRUCT_THREAD_TD_PCB | |
224 | /* In FreeBSD kernels for 5.0-RELEASE and later, the PCB no longer | |
225 | lives in `struct proc' but in `struct thread'. The `struct | |
226 | thread' for the initial thread for proc0 can be found in the | |
227 | variable "thread0". */ | |
228 | ||
229 | memset (nl, 0, sizeof nl); | |
230 | nl[0].n_name = "_thread0"; | |
231 | ||
232 | if (kvm_nlist (core_kd, nl) == -1) | |
8a3fe4f8 | 233 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 MK |
234 | |
235 | if (nl[0].n_value != 0) | |
236 | { | |
237 | struct pcb *paddr; | |
238 | ||
239 | /* Found thread0. */ | |
efe1d7b9 MK |
240 | nl[0].n_value += offsetof (struct thread, td_pcb); |
241 | if (kvm_read (core_kd, nl[0].n_value, &paddr, sizeof paddr) == -1) | |
8a3fe4f8 | 242 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 | 243 | |
56be3814 | 244 | bsd_kvm_fetch_pcb (regcache, paddr); |
2e0c3539 MK |
245 | return; |
246 | } | |
247 | #endif | |
248 | ||
3d263c1d BI |
249 | /* i18n: PCB == "Process Control Block" */ |
250 | error (_("Cannot find a valid PCB")); | |
2e0c3539 MK |
251 | } |
252 | \f | |
253 | ||
963c4174 | 254 | /* Kernel memory interface commands. */ |
fdb1bf9d | 255 | struct cmd_list_element *bsd_kvm_cmdlist; |
963c4174 MK |
256 | |
257 | static void | |
258 | bsd_kvm_cmd (char *arg, int fromtty) | |
259 | { | |
260 | /* ??? Should this become an alias for "target kvm"? */ | |
261 | } | |
262 | ||
263 | #ifndef HAVE_STRUCT_THREAD_TD_PCB | |
264 | ||
265 | static void | |
266 | bsd_kvm_proc_cmd (char *arg, int fromtty) | |
267 | { | |
268 | CORE_ADDR addr; | |
269 | ||
270 | if (arg == NULL) | |
3d263c1d | 271 | error_no_arg (_("proc address")); |
963c4174 MK |
272 | |
273 | if (core_kd == NULL) | |
3d263c1d | 274 | error (_("No kernel memory image.")); |
963c4174 MK |
275 | |
276 | addr = parse_and_eval_address (arg); | |
da7d81e3 NW |
277 | #ifdef HAVE_STRUCT_LWP |
278 | addr += offsetof (struct lwp, l_addr); | |
279 | #else | |
963c4174 | 280 | addr += offsetof (struct proc, p_addr); |
da7d81e3 | 281 | #endif |
963c4174 MK |
282 | |
283 | if (kvm_read (core_kd, addr, &bsd_kvm_paddr, sizeof bsd_kvm_paddr) == -1) | |
8a3fe4f8 | 284 | error (("%s"), kvm_geterr (core_kd)); |
963c4174 | 285 | |
594f7785 | 286 | target_fetch_registers (get_current_regcache (), -1); |
963c4174 | 287 | |
35f196d9 | 288 | reinit_frame_cache (); |
b04f3ab4 | 289 | print_stack_frame (get_selected_frame (NULL), -1, 1); |
963c4174 MK |
290 | } |
291 | ||
292 | #endif | |
293 | ||
294 | static void | |
295 | bsd_kvm_pcb_cmd (char *arg, int fromtty) | |
296 | { | |
297 | if (arg == NULL) | |
3d263c1d BI |
298 | /* i18n: PCB == "Process Control Block" */ |
299 | error_no_arg (_("pcb address")); | |
963c4174 MK |
300 | |
301 | if (core_kd == NULL) | |
3d263c1d | 302 | error (_("No kernel memory image.")); |
963c4174 | 303 | |
57ac95b8 | 304 | bsd_kvm_paddr = (struct pcb *)(u_long) parse_and_eval_address (arg); |
963c4174 | 305 | |
594f7785 | 306 | target_fetch_registers (get_current_regcache (), -1); |
963c4174 | 307 | |
35f196d9 | 308 | reinit_frame_cache (); |
b04f3ab4 | 309 | print_stack_frame (get_selected_frame (NULL), -1, 1); |
963c4174 MK |
310 | } |
311 | ||
6c613132 PA |
312 | static int |
313 | bsd_kvm_thread_alive (ptid_t ptid) | |
314 | { | |
315 | return 1; | |
316 | } | |
317 | ||
318 | static char * | |
319 | bsd_kvm_pid_to_str (ptid_t ptid) | |
320 | { | |
321 | static char buf[64]; | |
322 | xsnprintf (buf, sizeof buf, "<kvm>"); | |
323 | return buf; | |
324 | } | |
325 | ||
2e0c3539 MK |
326 | /* Add the libkvm interface to the list of all possible targets and |
327 | register CUPPLY_PCB as the architecture-specific process control | |
328 | block interpreter. */ | |
329 | ||
330 | void | |
331 | bsd_kvm_add_target (int (*supply_pcb)(struct regcache *, struct pcb *)) | |
332 | { | |
333 | gdb_assert (bsd_kvm_supply_pcb == NULL); | |
334 | bsd_kvm_supply_pcb = supply_pcb; | |
335 | ||
336 | bsd_kvm_ops.to_shortname = "kvm"; | |
3d263c1d BI |
337 | bsd_kvm_ops.to_longname = _("Kernel memory interface"); |
338 | bsd_kvm_ops.to_doc = _("Use a kernel virtual memory image as a target.\n\ | |
339 | Optionally specify the filename of a core dump."); | |
2e0c3539 MK |
340 | bsd_kvm_ops.to_open = bsd_kvm_open; |
341 | bsd_kvm_ops.to_close = bsd_kvm_close; | |
342 | bsd_kvm_ops.to_fetch_registers = bsd_kvm_fetch_registers; | |
961cb7b5 | 343 | bsd_kvm_ops.to_xfer_partial = bsd_kvm_xfer_partial; |
2e5a5020 | 344 | bsd_kvm_ops.to_files_info = bsd_kvm_files_info; |
6c613132 PA |
345 | bsd_kvm_ops.to_thread_alive = bsd_kvm_thread_alive; |
346 | bsd_kvm_ops.to_pid_to_str = bsd_kvm_pid_to_str; | |
2e0c3539 MK |
347 | bsd_kvm_ops.to_stratum = process_stratum; |
348 | bsd_kvm_ops.to_has_memory = 1; | |
349 | bsd_kvm_ops.to_has_stack = 1; | |
350 | bsd_kvm_ops.to_has_registers = 1; | |
351 | bsd_kvm_ops.to_magic = OPS_MAGIC; | |
352 | ||
353 | add_target (&bsd_kvm_ops); | |
963c4174 | 354 | |
3d263c1d BI |
355 | add_prefix_cmd ("kvm", class_obscure, bsd_kvm_cmd, _("\ |
356 | Generic command for manipulating the kernel memory interface."), | |
963c4174 MK |
357 | &bsd_kvm_cmdlist, "kvm ", 0, &cmdlist); |
358 | ||
359 | #ifndef HAVE_STRUCT_THREAD_TD_PCB | |
360 | add_cmd ("proc", class_obscure, bsd_kvm_proc_cmd, | |
3d263c1d | 361 | _("Set current context from proc address"), &bsd_kvm_cmdlist); |
963c4174 MK |
362 | #endif |
363 | add_cmd ("pcb", class_obscure, bsd_kvm_pcb_cmd, | |
3d263c1d BI |
364 | /* i18n: PCB == "Process Control Block" */ |
365 | _("Set current context from pcb address"), &bsd_kvm_cmdlist); | |
6c613132 PA |
366 | |
367 | /* Some notes on the ptid usage on this target. | |
368 | ||
369 | The pid field represents the kvm inferior instance. Currently, | |
370 | we don't support multiple kvm inferiors, but we start at 1 | |
371 | anyway. The lwp field is set to != 0, in case the core wants to | |
372 | refer to the whole kvm inferior with ptid(1,0,0). | |
373 | ||
374 | If kvm is made to export running processes as gdb threads, | |
375 | the following form can be used: | |
376 | ptid (1, 1, 0) -> kvm inferior 1, in kernel | |
377 | ptid (1, 1, 1) -> kvm inferior 1, process 1 | |
378 | ptid (1, 1, 2) -> kvm inferior 1, process 2 | |
379 | ptid (1, 1, n) -> kvm inferior 1, process n | |
380 | */ | |
381 | bsd_kvm_ptid = ptid_build (1, 1, 0); | |
2e0c3539 | 382 | } |