xref: /illumos-gate/usr/src/cmd/mdb/common/kmdb/kmdb_main.c (revision d5b563f27eb78296f57dddced6755afe7445c4b9)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <sys/types.h>
27 #include <sys/mman.h>
28 #include <sys/resource.h>
29 #include <sys/termios.h>
30 #include <sys/param.h>
31 #include <sys/salib.h>
32 
33 #include <alloca.h>
34 #include <unistd.h>
35 #include <string.h>
36 #include <stdlib.h>
37 #include <fcntl.h>
38 #include <libctf.h>
39 #include <errno.h>
40 #include <ctype.h>
41 
42 #include <kmdb/kmdb_promif.h>
43 #include <kmdb/kmdb_dpi.h>
44 #include <kmdb/kmdb_umemglue.h>
45 #include <kmdb/kmdb_io.h>
46 #include <kmdb/kmdb_dpi.h>
47 #include <kmdb/kmdb_wr.h>
48 #include <kmdb/kmdb_start.h>
49 #include <kmdb/kmdb_kdi.h>
50 #include <kmdb/kmdb_kvm.h>
51 #include <mdb/mdb_lex.h>
52 #include <mdb/mdb_debug.h>
53 #include <mdb/mdb_signal.h>
54 #include <mdb/mdb_string.h>
55 #include <mdb/mdb_modapi.h>
56 #include <mdb/mdb_target.h>
57 #include <mdb/mdb_gelf.h>
58 #include <mdb/mdb_conf.h>
59 #include <mdb/mdb_err.h>
60 #include <mdb/mdb_io_impl.h>
61 #include <mdb/mdb_frame.h>
62 #include <mdb/mdb_set.h>
63 #include <mdb/mdb.h>
64 
65 #ifdef __sparc
66 #define	KMDB_STACK_SIZE	(384 * 1024)
67 #else
68 #define	KMDB_STACK_SIZE (192 * 1024)
69 #endif
70 
71 caddr_t kmdb_main_stack;
72 size_t kmdb_main_stack_size;
73 
74 #define	KMDB_DEF_IPATH	"internal"
75 #if defined(_LP64)
76 #define	KMDB_DEF_LPATH	\
77 	"%r/platform/%p/kernel/kmdb/%i:" \
78 	"%r/platform/%m/kernel/kmdb/%i:" \
79 	"%r/kernel/kmdb/%i"
80 #else
81 #define	KMDB_DEF_LPATH	\
82 	"%r/platform/%m/kernel/kmdb:" \
83 	"%r/kernel/kmdb"
84 #endif
85 
86 #define	MDB_DEF_PROMPT "[%<_cpuid>]> "
87 
88 #define	KMDB_DEF_TERM_TYPE	"vt100"
89 
90 /*
91  * Similar to the panic_* variables in the kernel, we keep some relevant
92  * information stored in a set of global _mdb_abort_* variables; in the
93  * event that the debugger dumps core, these will aid core dump analysis.
94  */
95 const char *volatile _mdb_abort_str;	/* reason for failure */
96 
97 /*
98  * The kernel supplies a space-delimited list of directories
99  * (/platform/sun4u/kernel /kernel /usr/kernel ...) which we must transform into
100  * a debugger-friendly, colon-delimited module search path.  We add the kmdb
101  * module directory to each component and change the delimiter.
102  */
103 static char *
104 kmdb_modpath2lpath(const char *modpath)
105 {
106 #ifdef	_LP64
107 	static const char suffix[] = "/kmdb/%i:";
108 #else
109 	static const char suffix[] = "/kmdb:";
110 #endif
111 	const char *c;
112 	char *lpath, *lpend, *nlpath;
113 	size_t lpsz, lpres;
114 
115 	if (strchr(modpath, ':') != NULL) {
116 		warn("invalid kernel module path\n");
117 		return (NULL);
118 	}
119 
120 	lpres = lpsz = strlen(modpath) + MAXPATHLEN;
121 	lpend = lpath = mdb_zalloc(lpsz, UM_SLEEP);
122 
123 	while (isspace(*modpath))
124 		modpath++;
125 
126 	for (; *modpath != '\0'; modpath = c) {
127 		size_t sz;
128 
129 		for (c = modpath; !isspace(*c) && *c != '\0'; c++)
130 			continue;
131 
132 		sz = (c - modpath) + sizeof (suffix) - 1;
133 		if (sz >= lpres)
134 			continue;
135 
136 		(void) strncpy(lpend, modpath, c - modpath);
137 		(void) strcpy(lpend + (c - modpath), suffix);
138 
139 		lpend += sz;
140 		lpres -= sz;
141 
142 		while (isspace(*c))
143 			c++;
144 	}
145 
146 	if (lpend != lpath)
147 		lpend[-1] = '\0';	/* eat trailing colon */
148 
149 	nlpath = strdup(lpath);
150 	mdb_free(lpath, lpsz);
151 	return (nlpath);
152 }
153 
154 /*
155  * called while the kernel is running
156  */
157 int
158 kmdb_init(const char *execname, kmdb_auxv_t *kav)
159 {
160 	mdb_io_t *in_io, *out_io, *err_io, *null_io;
161 	mdb_tgt_ctor_f *tgt_ctor = kmdb_kvm_create;
162 	mdb_tgt_t *tgt;
163 	int i;
164 
165 	/*
166 	 * The beginnings of debugger initialization are a bit of a dance, due
167 	 * to interlocking dependencies between kmdb_prom_init,
168 	 * mdb_umem_startup, and mdb_create.  In particular, allocator
169 	 * initialization can't begin until prom_init() is called,
170 	 * kmdb_prom_init can't finish until the allocator is ready and
171 	 * mdb_create has been called.  We therefore split kmdb_prom_init into
172 	 * two pieces, and call thembefore and after umem initialization and
173 	 * mdb_create.
174 	 */
175 	kmdb_prom_init_begin("kmdb", kav);
176 	mdb_umem_startup(kav->kav_dseg, kav->kav_dseg_size,
177 	    kav->kav_pagesize);
178 	mdb_create(execname, "kmdb");
179 	kmdb_prom_init_finish(kav);
180 
181 	mdb.m_dseg = kav->kav_dseg;
182 	mdb.m_dsegsz = kav->kav_dseg_size;
183 
184 	out_io = kmdb_promio_create("stdout");
185 	mdb.m_out = mdb_iob_create(out_io, MDB_IOB_WRONLY);
186 
187 	err_io = kmdb_promio_create("stderr");
188 	mdb.m_err = mdb_iob_create(err_io, MDB_IOB_WRONLY);
189 	mdb_iob_clrflags(mdb.m_err, MDB_IOB_AUTOWRAP);
190 
191 	null_io = mdb_nullio_create();
192 	mdb.m_null = mdb_iob_create(null_io, MDB_IOB_WRONLY);
193 
194 	in_io = kmdb_promio_create("stdin");
195 	mdb.m_term = NULL;
196 
197 	if (kav->kav_config != NULL)
198 		mdb_set_config(kav->kav_config);
199 
200 	if (kav->kav_argv != NULL) {
201 		for (i = 0; kav->kav_argv[i] != NULL; i++) {
202 			if (!mdb_set_options(kav->kav_argv[i], TRUE))
203 				return (-1);
204 		}
205 	}
206 
207 	if (kav->kav_flags & KMDB_AUXV_FL_NOUNLOAD)
208 		mdb.m_flags |= MDB_FL_NOUNLOAD;
209 
210 	mdb.m_in = mdb_iob_create(in_io, MDB_IOB_RDONLY);
211 	mdb_iob_setflags(mdb.m_in, MDB_IOB_TTYLIKE);
212 
213 	mdb_lex_reset();
214 
215 	kmdb_kdi_init(kav->kav_kdi, kav);
216 
217 	if (kmdb_dpi_init(kav) < 0) {
218 		warn("Couldn't initialize kernel/PROM interface\n");
219 		return (-1);
220 	}
221 
222 	/*
223 	 * Path evaluation part 1: Create the initial module path to allow
224 	 * the target constructor to load a support module.  We base kmdb's
225 	 * module path off the kernel's module path unless the user has
226 	 * explicitly supplied one.
227 	 */
228 	mdb_set_ipath(KMDB_DEF_IPATH);
229 	if (strlen(mdb.m_lpathstr) > 0) {
230 		mdb_set_lpath(mdb.m_lpathstr);
231 	} else {
232 		char *lpath;
233 
234 		if (kav->kav_modpath != NULL && *kav->kav_modpath != '\0' &&
235 		    (lpath = kmdb_modpath2lpath(kav->kav_modpath)) != NULL) {
236 			mdb_set_lpath(lpath);
237 			strfree(lpath);
238 		} else {
239 			mdb_set_lpath(KMDB_DEF_LPATH);
240 		}
241 	}
242 
243 	if (mdb_get_prompt() == NULL)
244 		(void) mdb_set_prompt(MDB_DEF_PROMPT);
245 
246 	tgt = mdb_tgt_create(tgt_ctor, mdb.m_tgtflags, 0, NULL);
247 
248 	if (tgt == NULL) {
249 		warn("failed to initialize target");
250 		return (-1);
251 	}
252 
253 	mdb_tgt_activate(tgt);
254 
255 	mdb_create_loadable_disasms();
256 
257 	/*
258 	 * Path evaluation part 2: Re-evaluate the path now that the target
259 	 * is ready (and thus we have access to the real platform string).
260 	 */
261 	mdb_set_ipath(mdb.m_ipathstr);
262 	mdb_set_lpath(mdb.m_lpathstr);
263 
264 	if (!(mdb.m_flags & MDB_FL_NOMODS))
265 		mdb_module_load_all(MDB_MOD_DEFER);
266 
267 	/* Allocate the main debugger stack */
268 	kmdb_main_stack = mdb_alloc(KMDB_STACK_SIZE, UM_SLEEP);
269 	kmdb_main_stack_size = KMDB_STACK_SIZE;
270 
271 	kmdb_kdi_end_init();
272 
273 	return (0);
274 }
275 
276 #ifdef sun4v
277 
278 void
279 kmdb_init_promif(char *pgmname, kmdb_auxv_t *kav)
280 {
281 	kmdb_prom_init_promif(pgmname, kav);
282 }
283 
284 #else
285 
286 /*ARGSUSED*/
287 void
288 kmdb_init_promif(char *pgmname, kmdb_auxv_t *kav)
289 {
290 	/*
291 	 * Fake function for non sun4v. See comments in kmdb_ctl.h
292 	 */
293 	ASSERT(0);
294 }
295 
296 #endif
297 
298 /*
299  * First-time kmdb startup.  Run when kmdb has control of the machine for the
300  * first time.
301  */
302 static void
303 kmdb_startup(void)
304 {
305 	mdb_io_t *inio, *outio;
306 
307 	if (mdb.m_termtype == NULL) {
308 		/*
309 		 * The terminal type wasn't specified, so we guess.  If we're
310 		 * on console, we'll get a terminal type from the PROM.  If not,
311 		 * we'll use the default.
312 		 */
313 		const char *ttype;
314 
315 		if ((ttype = kmdb_prom_term_type()) == NULL) {
316 			ttype = KMDB_DEF_TERM_TYPE;
317 			warn("unable to determine terminal type: "
318 			    "assuming `%s'\n", ttype);
319 		}
320 
321 		mdb.m_flags |= MDB_FL_TERMGUESS;
322 		mdb.m_termtype = strdup(ttype);
323 
324 	} else if (mdb.m_flags & MDB_FL_TERMGUESS) {
325 		/*
326 		 * The terminal type wasn't specified by the user, but a guess
327 		 * was made using either $TERM or a property from the SMF.  A
328 		 * terminal type from the PROM code overrides the guess, so
329 		 * we'll use that if we can.
330 		 */
331 		char *promttype;
332 
333 		if ((promttype = kmdb_prom_term_type()) != NULL) {
334 			strfree(mdb.m_termtype);
335 			mdb.m_termtype = strdup(promttype);
336 		}
337 	}
338 
339 	inio = kmdb_promio_create("stdin");
340 	outio = kmdb_promio_create("stdout");
341 
342 	if ((mdb.m_term = mdb_termio_create(mdb.m_termtype, inio, outio)) ==
343 	    NULL && strcmp(mdb.m_termtype, KMDB_DEF_TERM_TYPE) != 0) {
344 		warn("failed to set terminal type to `%s', using `"
345 		    KMDB_DEF_TERM_TYPE "'\n", mdb.m_termtype);
346 
347 		strfree(mdb.m_termtype);
348 		mdb.m_termtype = strdup(KMDB_DEF_TERM_TYPE);
349 
350 		if ((mdb.m_term = mdb_termio_create(mdb.m_termtype, inio,
351 		    outio)) == NULL) {
352 			fail("failed to set terminal type to `"
353 			    KMDB_DEF_TERM_TYPE "'\n");
354 		}
355 	}
356 
357 	mdb_iob_destroy(mdb.m_in);
358 	mdb.m_in = mdb_iob_create(mdb.m_term, MDB_IOB_RDONLY);
359 	mdb_iob_setpager(mdb.m_out, mdb.m_term);
360 	mdb_iob_setflags(mdb.m_out, MDB_IOB_PGENABLE);
361 
362 	kmdb_kvm_startup();
363 
364 	/*
365 	 * kmdb_init() and kctl_activate() may have been talking to each other,
366 	 * and may have left some messages for us.  The driver -> debugger
367 	 * queue is normally processed during the resume path, so we have to
368 	 * do it manually here if we want it to be run for first startup.
369 	 */
370 	kmdb_dpi_process_work_queue();
371 
372 	kmdb_kvm_poststartup();
373 }
374 
375 void
376 kmdb_main(void)
377 {
378 	int status;
379 
380 	kmdb_dpi_set_state(DPI_STATE_STOPPED, 0);
381 	mdb_printf("\nWelcome to kmdb\n");
382 	kmdb_startup();
383 
384 	/*
385 	 * Debugger termination is a bit tricky.  For compatibility with kadb,
386 	 * neither an EOF on stdin nor a normal ::quit will cause the debugger
387 	 * to unload.  In both cases, they get a trip to OBP, after which the
388 	 * debugger returns.
389 	 *
390 	 * The only supported way to cause the debugger to unload is to specify
391 	 * the unload flag to ::quit, or to have the driver request it.  The
392 	 * driver request is the primary exit mechanism - the ::quit flag is
393 	 * provided for convenience.
394 	 *
395 	 * Both forms of "exit" (unqualified ::quit that won't cause an unload,
396 	 * and a driver request that will) are signalled by an MDB_ERR_QUIT.  In
397 	 * the latter case, however, the KDI will have the unload request.
398 	 */
399 	for (;;) {
400 		status = mdb_run();
401 
402 		if (status == MDB_ERR_QUIT && kmdb_kdi_get_unload_request()) {
403 			break;
404 
405 		} else if (status == MDB_ERR_QUIT || status == 0) {
406 			kmdb_dpi_enter_mon();
407 
408 		} else if (status == MDB_ERR_OUTPUT) {
409 			/*
410 			 * If a write failed on stdout, give up.  A more
411 			 * informative error message will already have been
412 			 * printed by mdb_run().
413 			 */
414 			if (mdb_iob_getflags(mdb.m_out) & MDB_IOB_ERR)
415 				fail("write to stdout failed, exiting\n");
416 
417 		} else if (status != MDB_ERR_ABORT) {
418 			fail("debugger exited abnormally (status = %s)\n",
419 			    mdb_err2str(status));
420 		}
421 	}
422 
423 	mdb_destroy();
424 
425 	kmdb_dpi_resume_unload();
426 
427 	/*NOTREACHED*/
428 }
429