xref: /dragonfly/gnu/usr.bin/gdb/kgdb/kthr.c (revision 6e278935)
1 /*
2  * Copyright (c) 2004 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD: src/gnu/usr.bin/gdb/kgdb/kthr.c,v 1.12 2008/05/01 20:36:48 jhb Exp $
27  */
28 
29 #include <sys/cdefs.h>
30 
31 #include <sys/param.h>
32 #include <machine/globaldata.h>
33 #include <sys/user.h>
34 #include <sys/types.h>
35 #include <sys/signal.h>
36 #include <err.h>
37 #include <inttypes.h>
38 #include <kvm.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 
43 #include <defs.h>
44 #include <frame-unwind.h>
45 #include <inferior.h>
46 
47 #include "kgdb.h"
48 
49 static CORE_ADDR dumppcb;
50 static int dumptid;
51 
52 static struct kthr *first;
53 struct kthr *curkthr;
54 
55 CORE_ADDR
56 kgdb_lookup(const char *sym)
57 {
58 	struct nlist nl[2];
59 
60 	nl[0].n_name = (char *)(CORE_ADDR)sym;
61 	nl[1].n_name = NULL;
62 	if (kvm_nlist(kvm, nl) != 0)
63 		return (0);
64 	return (nl[0].n_value);
65 }
66 
67 struct kthr *
68 kgdb_thr_first(void)
69 {
70 	return (first);
71 }
72 
73 struct kthr *
74 kgdb_thr_init(void)
75 {
76 	struct proc p;
77 	struct thread td;
78 	struct lwp lwp;
79 	struct mdglobaldata gd;
80 	struct kthr *kt;
81 	CORE_ADDR addr, paddr, prvspace;
82 	int cpu, ncpus;
83 
84 	while (first != NULL) {
85 		kt = first;
86 		first = kt->next;
87 		free(kt);
88 	}
89 
90 	addr = kgdb_lookup("_ncpus");
91 	if (addr == 0)
92 		return (NULL);
93 	kvm_read(kvm, addr, &ncpus, sizeof(ncpus));
94 
95 	dumppcb = kgdb_lookup("_dumppcb");
96 	if (dumppcb == 0)
97 		return (NULL);
98 
99 	prvspace = kgdb_lookup("_CPU_prvspace");
100 	if (prvspace == 0)
101 		return (NULL);
102 
103 	addr = kgdb_lookup("_dumpthread");
104 	if (addr != 0) {
105 		kvm_read(kvm, addr, &dumptid, sizeof(dumptid));
106 	} else {
107 		/*
108 		 * XXX Well then.  We don't know who dumped us.
109 		 * We could do some fancy stack matching, but
110 		 * I doubt this will work.  For now just use
111 		 * cpu0's curthread.
112 		 *
113 		 * Actually we don't even know if we were dumped
114 		 * or if we are life.  Find out by querying "dumping".
115 		 */
116 		int dumping = 0;
117 
118 		addr = kgdb_lookup("_dumping");
119 		kvm_read(kvm, addr, &dumping, sizeof(dumping));
120 		if (dumping) {
121 			kvm_read(kvm, prvspace +
122 				 offsetof(struct privatespace, mdglobaldata),
123 				 &gd, sizeof(struct mdglobaldata));
124 			dumptid = (intptr_t)gd.mi.gd_curthread;
125 		} else {
126 			/* We must be a live system */
127 			dumptid = -1;
128 		}
129 	}
130 
131 	for (cpu = 0; cpu < ncpus; cpu++) {
132 		kvm_read(kvm, prvspace +
133 			 cpu * sizeof(struct privatespace) +
134 			 offsetof(struct privatespace, mdglobaldata),
135 			 &gd, sizeof(struct mdglobaldata));
136 
137 		addr = (uintptr_t)TAILQ_FIRST(&gd.mi.gd_tdallq);
138 		while (addr != 0) {
139 			if (kvm_read(kvm, addr, &td, sizeof(td)) != sizeof(td)) {
140 				warnx("kvm_read: %s, while accessing thread",
141 				      kvm_geterr(kvm));
142 				break;
143 			}
144 			kt = malloc(sizeof(*kt));
145 			kt->next = first;
146 			kt->kaddr = addr;
147 			kt->tid = addr;		/* XXX do we have tids? */
148 			kt->pcb = (kt->tid == dumptid) ? dumppcb :
149 			    (uintptr_t)td.td_pcb;
150 			kt->kstack = (uintptr_t)td.td_kstack;
151 			if (td.td_proc != NULL) {
152 				paddr = (uintptr_t)td.td_proc;
153 				if (kvm_read(kvm, paddr, &p, sizeof(p)) != sizeof(p))
154 					warnx("kvm_read: %s", kvm_geterr(kvm));
155 				kt->pid = p.p_pid;
156 				kt->paddr = paddr;
157 				addr = (uintptr_t)td.td_lwp;
158 				if (kvm_read(kvm, addr, &lwp, sizeof(lwp)) != sizeof(lwp))
159 					warnx("kvm_read: %s", kvm_geterr(kvm));
160 				kt->lwpid = lwp.lwp_tid;
161 			} else {
162 				/*
163 				 * XXX for some stupid reason, gdb uses pid == -1
164 				 * as a marker for "dead" threads, so we have to
165 				 * hook all kernel threads on a different pid :/
166 				 */
167 				kt->pid = -2;
168 				kt->paddr = 0;
169 				/*
170 				 * We are a kernel thread, so our td_pcb is
171 				 * not used anyways.  An exception is the
172 				 * dumping thread.
173 				 * kt->pcb == 0 is a marker for
174 				 * "non-dumping kernel thread".
175 				 */
176 				if (kt->tid != dumptid)
177 					kt->pcb = 0;
178 			}
179 			first = kt;
180 			addr = (uintptr_t)TAILQ_NEXT(&td, td_allq);
181 		}
182 	}
183 
184 	curkthr = kgdb_thr_lookup_tid(dumptid);
185 	if (curkthr == NULL)
186 		curkthr = first;
187 	return (first);
188 }
189 
190 struct kthr *
191 kgdb_thr_lookup_tid(int tid)
192 {
193 	struct kthr *kt;
194 
195 	kt = first;
196 	while (kt != NULL && kt->tid != tid)
197 		kt = kt->next;
198 	return (kt);
199 }
200 
201 struct kthr *
202 kgdb_thr_lookup_taddr(uintptr_t taddr)
203 {
204 	struct kthr *kt;
205 
206 	kt = first;
207 	while (kt != NULL && kt->kaddr != taddr)
208 		kt = kt->next;
209 	return (kt);
210 }
211 
212 struct kthr *
213 kgdb_thr_lookup_pid(int pid)
214 {
215 	struct kthr *kt;
216 
217 	kt = first;
218 	while (kt != NULL && kt->pid != pid)
219 		kt = kt->next;
220 	return (kt);
221 }
222 
223 struct kthr *
224 kgdb_thr_lookup_paddr(uintptr_t paddr)
225 {
226 	struct kthr *kt;
227 
228 	kt = first;
229 	while (kt != NULL && kt->paddr != paddr)
230 		kt = kt->next;
231 	return (kt);
232 }
233 
234 struct kthr *
235 kgdb_thr_next(struct kthr *kt)
236 {
237 	return (kt->next);
238 }
239 
240 struct kthr *
241 kgdb_thr_select(struct kthr *kt)
242 {
243 	struct kthr *pcur;
244 
245 	pcur = curkthr;
246 	curkthr = kt;
247 	return (pcur);
248 }
249 
250 char *
251 kgdb_thr_extra_thread_info(int tid)
252 {
253 	struct kthr *kt;
254 	static char buf[64];
255 
256 	kt = kgdb_thr_lookup_tid(tid);
257 	if (kt == NULL)
258 		return (NULL);
259 
260 	buf[0] = 0;
261 
262 	return (NULL);
263 }
264 
265 char *
266 kgdb_thr_pid_to_str(ptid_t ptid)
267 {
268 	char comm[MAXCOMLEN + 1];
269 	struct kthr *kt;
270 	struct proc *p;
271 	struct thread *t;
272 	static char buf[64];
273 	int tid;
274 
275 	tid = ptid_get_tid(ptid);
276 	if (tid == 0)
277 		kt = kgdb_thr_lookup_pid(ptid_get_pid(ptid));
278 	else
279 		kt = kgdb_thr_lookup_tid(tid);
280 
281 	if (kt == NULL)
282 		return (NULL);
283 
284 	buf[0] = 0;
285 
286 	if (kt->pid != -2) {
287 		snprintf(buf, sizeof(buf), "pid %d", kt->pid);
288 
289 		if (tid != 0)
290 			snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
291 				 "/%d", kt->lwpid);
292 
293 		p = (struct proc *)kt->paddr;
294 		if (kvm_read(kvm, (uintptr_t)&p->p_comm[0], &comm, sizeof(comm)) !=
295 		    sizeof(comm))
296 			return (buf);
297 
298 		strlcat(buf, ", ", sizeof(buf));
299 		strlcat(buf, comm, sizeof(buf));
300 	} else {
301 		strcpy(buf, "kernel");
302 
303 		if (tid != 0) {
304 			t = (struct thread *)kt->kaddr;
305 			if (kvm_read(kvm, (uintptr_t)&t->td_comm[0], &comm,
306 			    sizeof(comm)) == sizeof(comm)) {
307 				strlcat(buf, " ", sizeof(buf));
308 				strlcat(buf, comm, sizeof(buf));
309 			}
310 		}
311 	}
312 
313 	return (buf);
314 }
315