xref: /dragonfly/gnu/usr.bin/gdb/kgdb/kthr.c (revision e69ec5f0230fbb05be3363d06adc7adbd56fdf3f)
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 CORE_ADDR dumptid;
51 
52 static struct kthr *first;
53 struct kthr *curkthr;
54 
55 #define LIVESYS_DUMPTID       10
56 
57 CORE_ADDR
kgdb_lookup(const char * sym)58 kgdb_lookup(const char *sym)
59 {
60           struct nlist nl[2];
61 
62           nl[0].n_name = (char *)(CORE_ADDR)sym;
63           nl[1].n_name = NULL;
64           if (kvm_nlist(kvm, nl) != 0)
65                     return (0);
66           return (nl[0].n_value);
67 }
68 
69 struct kthr *
kgdb_thr_first(void)70 kgdb_thr_first(void)
71 {
72           return (first);
73 }
74 
75 struct kthr *
kgdb_thr_init(void)76 kgdb_thr_init(void)
77 {
78           struct proc p;
79           struct thread td;
80           struct lwp lwp;
81           struct mdglobaldata gd;
82           struct kthr *kt;
83           CORE_ADDR addr, paddr, prvspace, gdptr;
84           int cpu, ncpus;
85 
86           while (first != NULL) {
87                     kt = first;
88                     first = kt->next;
89                     free(kt);
90           }
91 
92           addr = kgdb_lookup("_ncpus");
93           if (addr == 0)
94                     return (NULL);
95           kvm_read(kvm, addr, &ncpus, sizeof(ncpus));
96 
97           dumppcb = kgdb_lookup("_dumppcb");
98           if (dumppcb == 0)
99                     return (NULL);
100 
101           prvspace = kgdb_lookup("_CPU_prvspace");
102           if (prvspace == 0)
103                     return (NULL);
104 
105           addr = kgdb_lookup("_dumpthread");
106           if (addr != 0) {
107                     kvm_read(kvm, addr, &dumptid, sizeof(dumptid));
108           } else {
109                     /*
110                      * XXX Well then.  We don't know who dumped us.
111                      * We could do some fancy stack matching, but
112                      * I doubt this will work.  For now just use
113                      * cpu0's curthread.
114                      *
115                      * Actually we don't even know if we were dumped
116                      * or if we are live.  Find out by querying "dumping".
117                      */
118                     int dumping = 0;
119 
120                     addr = kgdb_lookup("_dumping");
121                     kvm_read(kvm, addr, &dumping, sizeof(dumping));
122                     if (dumping) {
123                               kvm_read(kvm, prvspace + 0, &gdptr, sizeof(gdptr));
124                               kvm_read(kvm, gdptr +
125                                          offsetof(struct privatespace, mdglobaldata),
126                                          &gd, sizeof(struct mdglobaldata));
127                               dumptid = (CORE_ADDR)gd.mi.gd_curthread;
128                     } else {
129                               /* We must be a live system */
130                               dumptid = LIVESYS_DUMPTID;
131                     }
132           }
133 
134           for (cpu = 0; cpu < ncpus; cpu++) {
135                     kvm_read(kvm, prvspace + cpu * sizeof(void *),
136                                &gdptr, sizeof(gdptr));
137                     kvm_read(kvm, gdptr +
138                                offsetof(struct privatespace, mdglobaldata),
139                                &gd, sizeof(struct mdglobaldata));
140 
141                     addr = (uintptr_t)TAILQ_FIRST(&gd.mi.gd_tdallq);
142                     while (addr != 0) {
143                               if (kvm_read(kvm, addr, &td, sizeof(td)) != sizeof(td)) {
144                                         warnx("kvm_read: %s, while accessing thread",
145                                               kvm_geterr(kvm));
146                                         break;
147                               }
148                               kt = malloc(sizeof(*kt));
149                               kt->next = first;
150                               kt->kaddr = addr;
151                               kt->tid = addr;
152                               kt->pcb = (kt->tid == dumptid) ? dumppcb :
153                                   (uintptr_t)td.td_pcb;
154                               kt->kstack = (uintptr_t)td.td_kstack;
155                               if (td.td_proc != NULL) {
156                                         paddr = (uintptr_t)td.td_proc;
157                                         if (kvm_read(kvm, paddr, &p, sizeof(p)) != sizeof(p))
158                                                   warnx("kvm_read: %s", kvm_geterr(kvm));
159                                         kt->pid = p.p_pid;
160                                         kt->paddr = paddr;
161                                         addr = (uintptr_t)td.td_lwp;
162                                         if (kvm_read(kvm, addr, &lwp, sizeof(lwp)) != sizeof(lwp))
163                                                   warnx("kvm_read: %s", kvm_geterr(kvm));
164                                         kt->lwpid = lwp.lwp_tid;
165                               } else {
166                                         /*
167                                          * XXX for some stupid reason, gdb uses pid == -1
168                                          * as a marker for "dead" threads, so we have to
169                                          * hook all kernel threads on a different pid :/
170                                          */
171                                         kt->pid = -2;
172                                         kt->paddr = 0;
173                                         /*
174                                          * We are a kernel thread, so our td_pcb is
175                                          * not used anyways.  An exception is the
176                                          * dumping thread.
177                                          * kt->pcb == 0 is a marker for
178                                          * "non-dumping kernel thread".
179                                          */
180                                         if (kt->tid != dumptid)
181                                                   kt->pcb = 0;
182                               }
183                               first = kt;
184                               addr = (uintptr_t)TAILQ_NEXT(&td, td_allq);
185                     }
186           }
187 
188           curkthr = kgdb_thr_lookup_tid(dumptid);
189           if (curkthr == NULL)
190                     curkthr = first;
191           return (first);
192 }
193 
194 struct kthr *
kgdb_thr_lookup_tid(CORE_ADDR tid)195 kgdb_thr_lookup_tid(CORE_ADDR tid)
196 {
197           struct kthr *kt;
198 
199           kt = first;
200           while (kt != NULL && kt->tid != tid)
201                     kt = kt->next;
202           return (kt);
203 }
204 
205 struct kthr *
kgdb_thr_lookup_taddr(uintptr_t taddr)206 kgdb_thr_lookup_taddr(uintptr_t taddr)
207 {
208           struct kthr *kt;
209 
210           kt = first;
211           while (kt != NULL && kt->kaddr != taddr)
212                     kt = kt->next;
213           return (kt);
214 }
215 
216 struct kthr *
kgdb_thr_lookup_pid(int pid)217 kgdb_thr_lookup_pid(int pid)
218 {
219           struct kthr *kt;
220 
221           kt = first;
222           while (kt != NULL && kt->pid != pid)
223                     kt = kt->next;
224           return (kt);
225 }
226 
227 struct kthr *
kgdb_thr_lookup_paddr(uintptr_t paddr)228 kgdb_thr_lookup_paddr(uintptr_t paddr)
229 {
230           struct kthr *kt;
231 
232           kt = first;
233           while (kt != NULL && kt->paddr != paddr)
234                     kt = kt->next;
235           return (kt);
236 }
237 
238 struct kthr *
kgdb_thr_next(struct kthr * kt)239 kgdb_thr_next(struct kthr *kt)
240 {
241           return (kt->next);
242 }
243 
244 struct kthr *
kgdb_thr_select(struct kthr * kt)245 kgdb_thr_select(struct kthr *kt)
246 {
247           struct kthr *pcur;
248 
249           pcur = curkthr;
250           curkthr = kt;
251           return (pcur);
252 }
253 
254 char *
kgdb_thr_extra_thread_info(CORE_ADDR tid)255 kgdb_thr_extra_thread_info(CORE_ADDR tid)
256 {
257 #if 0 /* Information already provided */
258           struct kthr *kt;
259           static char buf[64];
260           struct proc *p;
261           char comm[MAXCOMLEN + 1];
262 
263           kt = kgdb_thr_lookup_tid(tid);
264           if (kt == NULL)
265                     return (NULL);
266 
267           snprintf(buf, sizeof(buf), "PID=%d", kt->pid);
268           p = (struct proc *)kt->paddr;
269           if (kvm_read(kvm, (uintptr_t)&p->p_comm[0], &comm, sizeof(comm)) ==
270                     sizeof(comm)) {
271                     strlcat(buf, ": ", sizeof(buf));
272                     strlcat(buf, comm, sizeof(buf));
273           }
274           return (buf);
275 #endif
276           return (NULL);
277 }
278 
279 char *
kgdb_thr_pid_to_str(ptid_t ptid)280 kgdb_thr_pid_to_str(ptid_t ptid)
281 {
282           char comm[MAXCOMLEN + 1];
283           struct kthr *kt;
284           struct proc *p;
285           struct thread *t;
286           static char buf[64];
287           CORE_ADDR tid;
288 
289           tid = ptid_get_tid(ptid);
290           if (tid == 0)
291                     kt = kgdb_thr_lookup_pid(ptid_get_pid(ptid));
292           else
293                     kt = kgdb_thr_lookup_tid(tid);
294 
295           if (kt == NULL)
296                     return (NULL);
297 
298           buf[0] = 0;
299 
300           if (kt->pid != -2) {
301                     snprintf(buf, sizeof(buf), "pid %d", kt->pid);
302 
303                     if (tid != 0)
304                               snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
305                                          "/%ld", kt->lwpid);
306 
307                     p = (struct proc *)kt->paddr;
308                     if (kvm_read(kvm, (uintptr_t)&p->p_comm[0], &comm, sizeof(comm)) !=
309                         sizeof(comm))
310                               return (buf);
311 
312                     strlcat(buf, ", ", sizeof(buf));
313                     strlcat(buf, comm, sizeof(buf));
314           } else {
315                     strcpy(buf, "kernel");
316 
317                     if (tid != 0) {
318                               t = (struct thread *)kt->kaddr;
319                               if (kvm_read(kvm, (uintptr_t)&t->td_comm[0], &comm,
320                                   sizeof(comm)) == sizeof(comm)) {
321                                         strlcat(buf, " ", sizeof(buf));
322                                         strlcat(buf, comm, sizeof(buf));
323                               }
324                     }
325           }
326 
327           return (buf);
328 }
329