Commit | Line | Data |
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2e0c3539 MK |
1 | /* BSD Kernel Data Access Library (libkvm) interface. |
2 | ||
e2882c85 | 3 | Copyright (C) 2004-2018 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 | 19 | |
c49fbc6c | 20 | #define _KMEMUSER |
2e0c3539 | 21 | #include "defs.h" |
963c4174 MK |
22 | #include "cli/cli-cmds.h" |
23 | #include "command.h" | |
2e0c3539 MK |
24 | #include "frame.h" |
25 | #include "regcache.h" | |
26 | #include "target.h" | |
963c4174 | 27 | #include "value.h" |
7f245d65 | 28 | #include "gdbcore.h" /* for get_exec_file */ |
6c613132 | 29 | #include "gdbthread.h" |
2e0c3539 | 30 | |
2e0c3539 MK |
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> |
f7efc967 | 40 | #ifdef HAVE_SYS_USER_H |
2e0c3539 | 41 | #include <sys/user.h> |
f7efc967 | 42 | #endif |
2e0c3539 MK |
43 | |
44 | #include "bsd-kvm.h" | |
45 | ||
2e5a5020 MK |
46 | /* Kernel memory device file. */ |
47 | static const char *bsd_kvm_corefile; | |
48 | ||
2e0c3539 | 49 | /* Kernel memory interface descriptor. */ |
2e5a5020 | 50 | static kvm_t *core_kd; |
2e0c3539 MK |
51 | |
52 | /* Address of process control block. */ | |
2e5a5020 | 53 | static struct pcb *bsd_kvm_paddr; |
2e0c3539 MK |
54 | |
55 | /* Pointer to architecture-specific function that reconstructs the | |
56 | register state from PCB and supplies it to REGCACHE. */ | |
2e5a5020 | 57 | static int (*bsd_kvm_supply_pcb)(struct regcache *regcache, struct pcb *pcb); |
2e0c3539 | 58 | |
6c613132 PA |
59 | /* This is the ptid we use while we're connected to kvm. The kvm |
60 | target currently doesn't export any view of the running processes, | |
61 | so this represents the kernel task. */ | |
62 | static ptid_t bsd_kvm_ptid; | |
63 | ||
f6ac5f3d PA |
64 | /* The libkvm target. */ |
65 | ||
d9f719f1 PA |
66 | static const target_info bsd_kvm_target_info = { |
67 | "kvm", | |
68 | N_("Kernel memory interface"), | |
69 | N_("Use a kernel virtual memory image as a target.\n\ | |
70 | Optionally specify the filename of a core dump.") | |
71 | }; | |
72 | ||
f6ac5f3d PA |
73 | class bsd_kvm_target final : public target_ops |
74 | { | |
75 | public: | |
76 | bsd_kvm_target () | |
77 | { this->to_stratum = process_stratum; } | |
78 | ||
d9f719f1 PA |
79 | const target_info &info () const override |
80 | { return bsd_kvm_target_info; } | |
f6ac5f3d | 81 | |
f6ac5f3d PA |
82 | void close () override; |
83 | ||
84 | void fetch_registers (struct regcache *, int) override; | |
85 | enum target_xfer_status xfer_partial (enum target_object object, | |
86 | const char *annex, | |
87 | gdb_byte *readbuf, | |
88 | const gdb_byte *writebuf, | |
89 | ULONGEST offset, ULONGEST len, | |
90 | ULONGEST *xfered_len) override; | |
91 | ||
92 | void files_info () override; | |
57810aa7 | 93 | bool thread_alive (ptid_t ptid) override; |
f6ac5f3d PA |
94 | const char *pid_to_str (ptid_t) override; |
95 | ||
57810aa7 PA |
96 | bool has_memory () override { return true; } |
97 | bool has_stack () override { return true; } | |
98 | bool has_registers () override { return true; } | |
f6ac5f3d PA |
99 | }; |
100 | ||
101 | /* Target ops for libkvm interface. */ | |
102 | static bsd_kvm_target bsd_kvm_ops; | |
103 | ||
2e0c3539 | 104 | static void |
d9f719f1 | 105 | bsd_kvm_target_open (const char *arg, int from_tty) |
2e0c3539 MK |
106 | { |
107 | char errbuf[_POSIX2_LINE_MAX]; | |
108 | char *execfile = NULL; | |
109 | kvm_t *temp_kd; | |
014f9477 | 110 | char *filename = NULL; |
2e0c3539 MK |
111 | |
112 | target_preopen (from_tty); | |
113 | ||
014f9477 | 114 | if (arg) |
2e0c3539 MK |
115 | { |
116 | char *temp; | |
117 | ||
014f9477 | 118 | filename = tilde_expand (arg); |
2e0c3539 MK |
119 | if (filename[0] != '/') |
120 | { | |
1754f103 | 121 | temp = concat (current_directory, "/", filename, (char *)NULL); |
2e0c3539 MK |
122 | xfree (filename); |
123 | filename = temp; | |
124 | } | |
125 | } | |
126 | ||
7f245d65 | 127 | execfile = get_exec_file (0); |
4a35b02a NW |
128 | temp_kd = kvm_openfiles (execfile, filename, NULL, |
129 | write_files ? O_RDWR : O_RDONLY, errbuf); | |
2e0c3539 | 130 | if (temp_kd == NULL) |
8a3fe4f8 | 131 | error (("%s"), errbuf); |
2e0c3539 | 132 | |
2e5a5020 | 133 | bsd_kvm_corefile = filename; |
2e0c3539 MK |
134 | unpush_target (&bsd_kvm_ops); |
135 | core_kd = temp_kd; | |
136 | push_target (&bsd_kvm_ops); | |
137 | ||
6c613132 PA |
138 | add_thread_silent (bsd_kvm_ptid); |
139 | inferior_ptid = bsd_kvm_ptid; | |
140 | ||
594f7785 | 141 | target_fetch_registers (get_current_regcache (), -1); |
2e0c3539 | 142 | |
35f196d9 | 143 | reinit_frame_cache (); |
08d72866 | 144 | print_stack_frame (get_selected_frame (NULL), 0, SRC_AND_LOC, 1); |
2e0c3539 MK |
145 | } |
146 | ||
f6ac5f3d PA |
147 | void |
148 | bsd_kvm_target::close () | |
2e0c3539 MK |
149 | { |
150 | if (core_kd) | |
151 | { | |
152 | if (kvm_close (core_kd) == -1) | |
8a3fe4f8 | 153 | warning (("%s"), kvm_geterr(core_kd)); |
2e0c3539 MK |
154 | core_kd = NULL; |
155 | } | |
6c613132 PA |
156 | |
157 | inferior_ptid = null_ptid; | |
b7a08269 | 158 | discard_all_inferiors (); |
2e0c3539 MK |
159 | } |
160 | ||
961cb7b5 MK |
161 | static LONGEST |
162 | bsd_kvm_xfer_memory (CORE_ADDR addr, ULONGEST len, | |
163 | gdb_byte *readbuf, const gdb_byte *writebuf) | |
2e0c3539 | 164 | { |
961cb7b5 MK |
165 | ssize_t nbytes = len; |
166 | ||
167 | if (readbuf) | |
168 | nbytes = kvm_read (core_kd, addr, readbuf, nbytes); | |
169 | if (writebuf && nbytes > 0) | |
170 | nbytes = kvm_write (core_kd, addr, writebuf, nbytes); | |
171 | return nbytes; | |
172 | } | |
2e0c3539 | 173 | |
f6ac5f3d PA |
174 | enum target_xfer_status |
175 | bsd_kvm_target::xfer_partial (enum target_object object, | |
176 | const char *annex, gdb_byte *readbuf, | |
177 | const gdb_byte *writebuf, | |
178 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) | |
961cb7b5 MK |
179 | { |
180 | switch (object) | |
181 | { | |
182 | case TARGET_OBJECT_MEMORY: | |
9b409511 YQ |
183 | { |
184 | LONGEST ret = bsd_kvm_xfer_memory (offset, len, readbuf, writebuf); | |
185 | ||
186 | if (ret < 0) | |
187 | return TARGET_XFER_E_IO; | |
188 | else if (ret == 0) | |
189 | return TARGET_XFER_EOF; | |
190 | else | |
191 | { | |
192 | *xfered_len = (ULONGEST) ret; | |
193 | return TARGET_XFER_OK; | |
194 | } | |
195 | } | |
961cb7b5 MK |
196 | |
197 | default: | |
2ed4b548 | 198 | return TARGET_XFER_E_IO; |
961cb7b5 | 199 | } |
2e0c3539 MK |
200 | } |
201 | ||
f6ac5f3d PA |
202 | void |
203 | bsd_kvm_target::files_info () | |
2e5a5020 MK |
204 | { |
205 | if (bsd_kvm_corefile && strcmp (bsd_kvm_corefile, _PATH_MEM) != 0) | |
206 | printf_filtered (_("\tUsing the kernel crash dump %s.\n"), | |
207 | bsd_kvm_corefile); | |
208 | else | |
209 | printf_filtered (_("\tUsing the currently running kernel.\n")); | |
210 | } | |
211 | ||
2e0c3539 MK |
212 | /* Fetch process control block at address PADDR. */ |
213 | ||
214 | static int | |
56be3814 | 215 | bsd_kvm_fetch_pcb (struct regcache *regcache, struct pcb *paddr) |
2e0c3539 MK |
216 | { |
217 | struct pcb pcb; | |
218 | ||
219 | if (kvm_read (core_kd, (unsigned long) paddr, &pcb, sizeof pcb) == -1) | |
8a3fe4f8 | 220 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 MK |
221 | |
222 | gdb_assert (bsd_kvm_supply_pcb); | |
56be3814 | 223 | return bsd_kvm_supply_pcb (regcache, &pcb); |
2e0c3539 MK |
224 | } |
225 | ||
f6ac5f3d PA |
226 | void |
227 | bsd_kvm_target::fetch_registers (struct regcache *regcache, int regnum) | |
2e0c3539 MK |
228 | { |
229 | struct nlist nl[2]; | |
230 | ||
231 | if (bsd_kvm_paddr) | |
efe1d7b9 | 232 | { |
56be3814 | 233 | bsd_kvm_fetch_pcb (regcache, bsd_kvm_paddr); |
efe1d7b9 MK |
234 | return; |
235 | } | |
2e0c3539 MK |
236 | |
237 | /* On dumping core, BSD kernels store the faulting context (PCB) | |
238 | in the variable "dumppcb". */ | |
239 | memset (nl, 0, sizeof nl); | |
240 | nl[0].n_name = "_dumppcb"; | |
241 | ||
242 | if (kvm_nlist (core_kd, nl) == -1) | |
8a3fe4f8 | 243 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 MK |
244 | |
245 | if (nl[0].n_value != 0) | |
246 | { | |
4a64f543 | 247 | /* Found dumppcb. If it contains a valid context, return |
2e0c3539 | 248 | immediately. */ |
56be3814 | 249 | if (bsd_kvm_fetch_pcb (regcache, (struct pcb *) nl[0].n_value)) |
2e0c3539 MK |
250 | return; |
251 | } | |
252 | ||
253 | /* Traditional BSD kernels have a process proc0 that should always | |
254 | be present. The address of proc0's PCB is stored in the variable | |
255 | "proc0paddr". */ | |
256 | ||
257 | memset (nl, 0, sizeof nl); | |
258 | nl[0].n_name = "_proc0paddr"; | |
259 | ||
260 | if (kvm_nlist (core_kd, nl) == -1) | |
8a3fe4f8 | 261 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 MK |
262 | |
263 | if (nl[0].n_value != 0) | |
264 | { | |
265 | struct pcb *paddr; | |
266 | ||
267 | /* Found proc0paddr. */ | |
268 | if (kvm_read (core_kd, nl[0].n_value, &paddr, sizeof paddr) == -1) | |
8a3fe4f8 | 269 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 | 270 | |
56be3814 | 271 | bsd_kvm_fetch_pcb (regcache, paddr); |
2e0c3539 MK |
272 | return; |
273 | } | |
274 | ||
275 | #ifdef HAVE_STRUCT_THREAD_TD_PCB | |
276 | /* In FreeBSD kernels for 5.0-RELEASE and later, the PCB no longer | |
277 | lives in `struct proc' but in `struct thread'. The `struct | |
278 | thread' for the initial thread for proc0 can be found in the | |
279 | variable "thread0". */ | |
280 | ||
281 | memset (nl, 0, sizeof nl); | |
282 | nl[0].n_name = "_thread0"; | |
283 | ||
284 | if (kvm_nlist (core_kd, nl) == -1) | |
8a3fe4f8 | 285 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 MK |
286 | |
287 | if (nl[0].n_value != 0) | |
288 | { | |
289 | struct pcb *paddr; | |
290 | ||
291 | /* Found thread0. */ | |
efe1d7b9 MK |
292 | nl[0].n_value += offsetof (struct thread, td_pcb); |
293 | if (kvm_read (core_kd, nl[0].n_value, &paddr, sizeof paddr) == -1) | |
8a3fe4f8 | 294 | error (("%s"), kvm_geterr (core_kd)); |
2e0c3539 | 295 | |
56be3814 | 296 | bsd_kvm_fetch_pcb (regcache, paddr); |
2e0c3539 MK |
297 | return; |
298 | } | |
299 | #endif | |
300 | ||
0963b4bd | 301 | /* i18n: PCB == "Process Control Block". */ |
3d263c1d | 302 | error (_("Cannot find a valid PCB")); |
2e0c3539 MK |
303 | } |
304 | \f | |
305 | ||
963c4174 | 306 | /* Kernel memory interface commands. */ |
fdb1bf9d | 307 | struct cmd_list_element *bsd_kvm_cmdlist; |
963c4174 MK |
308 | |
309 | static void | |
981a3fb3 | 310 | bsd_kvm_cmd (const char *arg, int fromtty) |
963c4174 MK |
311 | { |
312 | /* ??? Should this become an alias for "target kvm"? */ | |
313 | } | |
314 | ||
315 | #ifndef HAVE_STRUCT_THREAD_TD_PCB | |
316 | ||
317 | static void | |
94765011 | 318 | bsd_kvm_proc_cmd (const char *arg, int fromtty) |
963c4174 MK |
319 | { |
320 | CORE_ADDR addr; | |
321 | ||
322 | if (arg == NULL) | |
3d263c1d | 323 | error_no_arg (_("proc address")); |
963c4174 MK |
324 | |
325 | if (core_kd == NULL) | |
3d263c1d | 326 | error (_("No kernel memory image.")); |
963c4174 MK |
327 | |
328 | addr = parse_and_eval_address (arg); | |
da7d81e3 NW |
329 | #ifdef HAVE_STRUCT_LWP |
330 | addr += offsetof (struct lwp, l_addr); | |
331 | #else | |
963c4174 | 332 | addr += offsetof (struct proc, p_addr); |
da7d81e3 | 333 | #endif |
963c4174 MK |
334 | |
335 | if (kvm_read (core_kd, addr, &bsd_kvm_paddr, sizeof bsd_kvm_paddr) == -1) | |
8a3fe4f8 | 336 | error (("%s"), kvm_geterr (core_kd)); |
963c4174 | 337 | |
594f7785 | 338 | target_fetch_registers (get_current_regcache (), -1); |
963c4174 | 339 | |
35f196d9 | 340 | reinit_frame_cache (); |
08d72866 | 341 | print_stack_frame (get_selected_frame (NULL), 0, SRC_AND_LOC, 1); |
963c4174 MK |
342 | } |
343 | ||
344 | #endif | |
345 | ||
346 | static void | |
94765011 | 347 | bsd_kvm_pcb_cmd (const char *arg, int fromtty) |
963c4174 MK |
348 | { |
349 | if (arg == NULL) | |
0963b4bd | 350 | /* i18n: PCB == "Process Control Block". */ |
3d263c1d | 351 | error_no_arg (_("pcb address")); |
963c4174 MK |
352 | |
353 | if (core_kd == NULL) | |
3d263c1d | 354 | error (_("No kernel memory image.")); |
963c4174 | 355 | |
57ac95b8 | 356 | bsd_kvm_paddr = (struct pcb *)(u_long) parse_and_eval_address (arg); |
963c4174 | 357 | |
594f7785 | 358 | target_fetch_registers (get_current_regcache (), -1); |
963c4174 | 359 | |
35f196d9 | 360 | reinit_frame_cache (); |
08d72866 | 361 | print_stack_frame (get_selected_frame (NULL), 0, SRC_AND_LOC, 1); |
963c4174 MK |
362 | } |
363 | ||
57810aa7 | 364 | bool |
f6ac5f3d | 365 | bsd_kvm_target::thread_alive (ptid_t ptid) |
6c613132 | 366 | { |
57810aa7 | 367 | return true; |
6c613132 PA |
368 | } |
369 | ||
f6ac5f3d PA |
370 | const char * |
371 | bsd_kvm_target::pid_to_str (ptid_t ptid) | |
6c613132 PA |
372 | { |
373 | static char buf[64]; | |
374 | xsnprintf (buf, sizeof buf, "<kvm>"); | |
375 | return buf; | |
376 | } | |
377 | ||
2e0c3539 MK |
378 | /* Add the libkvm interface to the list of all possible targets and |
379 | register CUPPLY_PCB as the architecture-specific process control | |
380 | block interpreter. */ | |
381 | ||
382 | void | |
383 | bsd_kvm_add_target (int (*supply_pcb)(struct regcache *, struct pcb *)) | |
384 | { | |
385 | gdb_assert (bsd_kvm_supply_pcb == NULL); | |
386 | bsd_kvm_supply_pcb = supply_pcb; | |
387 | ||
d9f719f1 | 388 | add_target (bsd_kvm_target_info, bsd_kvm_target_open); |
963c4174 | 389 | |
3d263c1d BI |
390 | add_prefix_cmd ("kvm", class_obscure, bsd_kvm_cmd, _("\ |
391 | Generic command for manipulating the kernel memory interface."), | |
963c4174 MK |
392 | &bsd_kvm_cmdlist, "kvm ", 0, &cmdlist); |
393 | ||
394 | #ifndef HAVE_STRUCT_THREAD_TD_PCB | |
395 | add_cmd ("proc", class_obscure, bsd_kvm_proc_cmd, | |
3d263c1d | 396 | _("Set current context from proc address"), &bsd_kvm_cmdlist); |
963c4174 MK |
397 | #endif |
398 | add_cmd ("pcb", class_obscure, bsd_kvm_pcb_cmd, | |
0963b4bd | 399 | /* i18n: PCB == "Process Control Block". */ |
3d263c1d | 400 | _("Set current context from pcb address"), &bsd_kvm_cmdlist); |
6c613132 PA |
401 | |
402 | /* Some notes on the ptid usage on this target. | |
403 | ||
404 | The pid field represents the kvm inferior instance. Currently, | |
405 | we don't support multiple kvm inferiors, but we start at 1 | |
406 | anyway. The lwp field is set to != 0, in case the core wants to | |
407 | refer to the whole kvm inferior with ptid(1,0,0). | |
408 | ||
409 | If kvm is made to export running processes as gdb threads, | |
410 | the following form can be used: | |
411 | ptid (1, 1, 0) -> kvm inferior 1, in kernel | |
412 | ptid (1, 1, 1) -> kvm inferior 1, process 1 | |
413 | ptid (1, 1, 2) -> kvm inferior 1, process 2 | |
0963b4bd MS |
414 | ptid (1, 1, n) -> kvm inferior 1, process n */ |
415 | ||
fd79271b | 416 | bsd_kvm_ptid = ptid_t (1, 1, 0); |
2e0c3539 | 417 | } |