1 /* Get thread information.
2 Copyright (C) 1999-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <stddef.h>
20 #include <string.h>
21 #include <stdint.h>
22 #include "thread_dbP.h"
23
24
25 td_err_e
26 td_thr_get_info (const td_thrhandle_t *th, td_thrinfo_t *infop)
27 {
28 td_err_e err;
29 void *copy;
30 psaddr_t tls, schedpolicy, schedprio, cancelhandling, tid, report_events;
31
32 LOG ("td_thr_get_info");
33
34 if (th->th_unique == 0)
35 {
36 /* Special case for the main thread before initialization. */
37 copy = NULL;
38 tls = 0;
39 cancelhandling = 0;
40 schedpolicy = SCHED_OTHER;
41 schedprio = 0;
42 tid = 0;
43
44 /* Ignore errors to obtain the __nptl_initial_report_events
45 value because GDB no longer uses the events interface, and
46 other libthread_db consumers hopefully can handle different
47 libpthread/lds.o load orders. */
48 report_events = 0;
49 (void) DB_GET_VALUE (report_events, th->th_ta_p,
50 __nptl_initial_report_events, 0);
51 err = TD_OK;
52 }
53 else
54 {
55 /* Copy the whole descriptor in once so we can access the several
56 fields locally. Excess copying in one go is much better than
57 multiple ps_pdread calls. */
58 err = DB_GET_STRUCT (copy, th->th_ta_p, th->th_unique, pthread);
59 if (err != TD_OK)
60 return err;
61
62 err = DB_GET_FIELD_ADDRESS (tls, th->th_ta_p, th->th_unique,
63 pthread, specific, 0);
64 if (err != TD_OK)
65 return err;
66
67 err = DB_GET_FIELD_LOCAL (schedpolicy, th->th_ta_p, copy, pthread,
68 schedpolicy, 0);
69 if (err != TD_OK)
70 return err;
71 err = DB_GET_FIELD_LOCAL (schedprio, th->th_ta_p, copy, pthread,
72 schedparam_sched_priority, 0);
73 if (err != TD_OK)
74 return err;
75 err = DB_GET_FIELD_LOCAL (tid, th->th_ta_p, copy, pthread, tid, 0);
76 if (err != TD_OK)
77 return err;
78 err = DB_GET_FIELD_LOCAL (cancelhandling, th->th_ta_p, copy, pthread,
79 cancelhandling, 0);
80 if (err != TD_OK)
81 return err;
82 err = DB_GET_FIELD_LOCAL (report_events, th->th_ta_p, copy, pthread,
83 report_events, 0);
84 }
85 if (err != TD_OK)
86 return err;
87
88 /* Fill in information. Clear first to provide reproducible
89 results for the fields we do not fill in. */
90 memset (infop, '\0', sizeof (td_thrinfo_t));
91
92 infop->ti_tid = (thread_t) th->th_unique;
93 infop->ti_tls = (char *) tls;
94 infop->ti_pri = ((uintptr_t) schedpolicy == SCHED_OTHER
95 ? 0 : (uintptr_t) schedprio);
96 infop->ti_type = TD_THR_USER;
97
98 if ((((int) (uintptr_t) cancelhandling) & EXITING_BITMASK) == 0)
99 /* XXX For now there is no way to get more information. */
100 infop->ti_state = TD_THR_ACTIVE;
101 else if ((((int) (uintptr_t) cancelhandling) & TERMINATED_BITMASK) == 0)
102 infop->ti_state = TD_THR_ZOMBIE;
103 else
104 infop->ti_state = TD_THR_UNKNOWN;
105
106 /* Initialization which are the same in both cases. */
107 infop->ti_ta_p = th->th_ta_p;
108 infop->ti_lid = tid == 0 ? ps_getpid (th->th_ta_p->ph) : (uintptr_t) tid;
109 infop->ti_traceme = report_events != 0;
110
111 if (copy != NULL)
112 err = DB_GET_FIELD_LOCAL (infop->ti_startfunc, th->th_ta_p, copy, pthread,
113 start_routine, 0);
114 if (copy != NULL && err == TD_OK)
115 {
116 uint32_t idx;
117 for (idx = 0; idx < TD_EVENTSIZE; ++idx)
118 {
119 psaddr_t word;
120 err = DB_GET_FIELD_LOCAL (word, th->th_ta_p, copy, pthread,
121 eventbuf_eventmask_event_bits, idx);
122 if (err != TD_OK)
123 break;
124 infop->ti_events.event_bits[idx] = (uintptr_t) word;
125 }
126 if (err == TD_NOAPLIC)
127 memset (&infop->ti_events.event_bits[idx], 0,
128 (TD_EVENTSIZE - idx) * sizeof infop->ti_events.event_bits[0]);
129 }
130
131 return err;
132 }