1 /* Validate a thread handle.
2    Copyright (C) 1999-2022 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 "thread_dbP.h"
20 #include <stdbool.h>
21 
22 td_err_e
__td_ta_stack_user(td_thragent_t * ta,psaddr_t * plist)23 __td_ta_stack_user (td_thragent_t *ta, psaddr_t *plist)
24 {
25   if (__td_ta_rtld_global (ta))
26     return DB_GET_FIELD_ADDRESS (*plist, ta, ta->ta_addr__rtld_global,
27 				 rtld_global, _dl_stack_user, 0);
28   else
29     {
30       if (ta->ta_addr__dl_stack_user == 0
31 	  && td_mod_lookup (ta->ph, NULL, SYM__dl_stack_user,
32 			    &ta->ta_addr__dl_stack_user) != PS_OK)
33 	return TD_ERR;
34       *plist = ta->ta_addr__dl_stack_user;
35       return TD_OK;
36     }
37 }
38 
39 td_err_e
__td_ta_stack_used(td_thragent_t * ta,psaddr_t * plist)40 __td_ta_stack_used (td_thragent_t *ta, psaddr_t *plist)
41 {
42 
43   if (__td_ta_rtld_global (ta))
44     return DB_GET_FIELD_ADDRESS (*plist, ta, ta->ta_addr__rtld_global,
45 				 rtld_global, _dl_stack_used, 0);
46   else
47     {
48       if (ta->ta_addr__dl_stack_used == 0
49 	  && td_mod_lookup (ta->ph, NULL, SYM__dl_stack_used,
50 			    &ta->ta_addr__dl_stack_used) != PS_OK)
51 	return TD_ERR;
52       *plist = ta->ta_addr__dl_stack_used;
53       return TD_OK;
54     }
55 }
56 
57 static td_err_e
check_thread_list(const td_thrhandle_t * th,psaddr_t head,bool * uninit)58 check_thread_list (const td_thrhandle_t *th, psaddr_t head, bool *uninit)
59 {
60   td_err_e err;
61   psaddr_t next, ofs;
62 
63   err = DB_GET_FIELD (next, th->th_ta_p, head, list_t, next, 0);
64   if (err == TD_OK)
65     {
66       if (next == 0)
67 	{
68 	  *uninit = true;
69 	  return TD_NOTHR;
70 	}
71       err = DB_GET_FIELD_ADDRESS (ofs, th->th_ta_p, 0, pthread, list, 0);
72     }
73 
74   while (err == TD_OK)
75     {
76       if (next == head)
77 	return TD_NOTHR;
78 
79       if (next - (ofs - (psaddr_t) 0) == th->th_unique)
80 	return TD_OK;
81 
82       err = DB_GET_FIELD (next, th->th_ta_p, next, list_t, next, 0);
83     }
84 
85   return err;
86 }
87 
88 
89 td_err_e
td_thr_validate(const td_thrhandle_t * th)90 td_thr_validate (const td_thrhandle_t *th)
91 {
92   td_err_e err;
93   psaddr_t list;
94 
95   LOG ("td_thr_validate");
96 
97   /* First check the list with threads using user allocated stacks.  */
98   bool uninit = false;
99   err = __td_ta_stack_user (th->th_ta_p, &list);
100   if (err == TD_OK)
101     err = check_thread_list (th, list, &uninit);
102 
103   /* If our thread is not on this list search the list with stack
104      using implementation allocated stacks.  */
105   if (err == TD_NOTHR)
106     {
107       err = __td_ta_stack_used (th->th_ta_p, &list);
108       if (err == TD_OK)
109 	err = check_thread_list (th, list, &uninit);
110 
111       if (err == TD_NOTHR && uninit && th->th_unique == 0)
112 	/* __pthread_initialize_minimal has not run yet.
113 	   There is only the special case thread handle.  */
114 	err = TD_OK;
115     }
116 
117   return err;
118 }
119