1 /* Private header for thread debug library
2 Copyright (C) 2003-2023 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 #ifndef _THREAD_DBP_H
20 #define _THREAD_DBP_H 1
21
22 #include <stdbool.h>
23 #include <stdint.h>
24 #include <string.h>
25 #include <stdlib.h>
26 #include <unistd.h>
27 #include <assert.h>
28 #include "proc_service.h"
29 #include "thread_db.h"
30 #include <pthreadP.h> /* This is for *_BITMASK only. */
31 #include <list.h>
32 #include <gnu/lib-names.h>
33 #include <libc-diag.h>
34
35 /* Indices for the symbol names. */
36 enum
37 {
38 # define DB_STRUCT(type) SYM_SIZEOF_##type,
39 # define DB_STRUCT_FIELD(type, field) SYM_##type##_FIELD_##field,
40 # define DB_STRUCT_FLEXIBLE_ARRAY(type, field) DB_STRUCT_FIELD (type, field)
41 # define DB_SYMBOL(name) SYM_##name,
42 # define DB_FUNCTION(name) SYM_##name,
43 # define DB_VARIABLE(name) SYM_##name, SYM_DESC_##name,
44 # include "structs.def"
45 # undef DB_STRUCT
46 # undef DB_STRUCT_FIELD
47 # undef DB_STRUCT_FLEXIBLE_ARRAY
48 # undef DB_SYMBOL
49 # undef DB_FUNCTION
50 # undef DB_VARIABLE
51
52 SYM_TH_UNIQUE_CONST_THREAD_AREA,
53 SYM_TH_UNIQUE_REGISTER64,
54 SYM_TH_UNIQUE_REGISTER32,
55 SYM_TH_UNIQUE_REGISTER64_THREAD_AREA,
56 SYM_TH_UNIQUE_REGISTER32_THREAD_AREA,
57
58 SYM_NUM_MESSAGES
59 };
60
61
62 /* Comment out the following for less verbose output. */
63 #ifndef NDEBUG
64 # define LOG(c) \
65 if (__td_debug) \
66 assert (write (2, c "\n", strlen (c "\n")) == strlen (c "\n"))
67 extern int __td_debug attribute_hidden;
68 #else
69 # define LOG(c)
70 #endif
71
72
73 #define DB_DESC_SIZE(desc) ((desc)[0])
74 #define DB_DESC_NELEM(desc) ((desc)[1])
75 #define DB_DESC_OFFSET(desc) ((desc)[2])
76 #define DB_SIZEOF_DESC (3 * sizeof (uint32_t))
77 #define DB_DEFINE_DESC(name, size, nelem, offset) \
78 const uint32_t name[3] = { (size), (nelem), (offset) }
79 typedef uint32_t db_desc_t[3];
80
81
82 /* Handle for a process. This type is opaque. */
83 struct td_thragent
84 {
85 /* Chain on the list of all agent structures. */
86 list_t list;
87
88 /* Delivered by the debugger and we have to pass it back in the
89 proc callbacks. */
90 struct ps_prochandle *ph;
91
92 /* Cached values read from the inferior. */
93 # define DB_STRUCT(type) \
94 uint32_t ta_sizeof_##type;
95 # define DB_STRUCT_FIELD(type, field) \
96 db_desc_t ta_field_##type##_##field;
97 # define DB_STRUCT_FLEXIBLE_ARRAY(type, field) DB_STRUCT_FIELD (type, field)
98 # define DB_SYMBOL(name) \
99 psaddr_t ta_addr_##name;
100 # define DB_FUNCTION(name) \
101 psaddr_t ta_addr_##name;
102 # define DB_VARIABLE(name) \
103 psaddr_t ta_addr_##name; \
104 db_desc_t ta_var_##name;
105 # include "structs.def"
106 # undef DB_STRUCT
107 # undef DB_STRUCT_FIELD
108 # undef DB_STRUCT_FLEXIBLE_ARRAY
109 # undef DB_FUNCTION
110 # undef DB_SYMBOL
111 # undef DB_VARIABLE
112
113 psaddr_t ta_addr__rtld_global;
114
115 /* The method of locating a thread's th_unique value. */
116 enum
117 {
118 ta_howto_unknown,
119 ta_howto_reg,
120 ta_howto_reg_thread_area,
121 ta_howto_const_thread_area
122 } ta_howto;
123 union
124 {
125 uint32_t const_thread_area; /* Constant argument to ps_get_thread_area. */
126 /* These are as if the descriptor of the field in prregset_t,
127 but DB_DESC_NELEM is overloaded as follows: */
128 db_desc_t reg; /* Signed bias applied to register value. */
129 db_desc_t reg_thread_area; /* Bits to scale down register value. */
130 } ta_howto_data;
131 };
132
133
134 /* List of all known descriptors. */
135 extern list_t __td_agent_list attribute_hidden;
136
137
138 /* Function used to test for correct thread agent pointer. */
139 static inline bool
140 ta_ok (const td_thragent_t *ta)
141 {
142 list_t *runp;
143
144 list_for_each (runp, &__td_agent_list)
145 if (list_entry (runp, td_thragent_t, list) == ta)
146 return true;
147
148 return false;
149 }
150
151
152 /* Internal wrappers around ps_pglobal_lookup. */
153 extern ps_err_e td_mod_lookup (struct ps_prochandle *ps, const char *modname,
154 int idx, psaddr_t *sym_addr) attribute_hidden;
155 #define td_lookup(ps, idx, sym_addr) \
156 td_mod_lookup ((ps), LIBPTHREAD_SO, (idx), (sym_addr))
157
158
159 /* Store in psaddr_t VAR the address of inferior's symbol NAME. */
160 #define DB_GET_SYMBOL(var, ta, name) \
161 (((ta)->ta_addr_##name == 0 \
162 && td_lookup ((ta)->ph, SYM_##name, &(ta)->ta_addr_##name) != PS_OK) \
163 ? TD_ERR : ((var) = (ta)->ta_addr_##name, TD_OK))
164
165 /* Store in psaddr_t VAR the value of ((TYPE) PTR)->FIELD[IDX] in the inferior.
166 A target field smaller than psaddr_t is zero-extended. */
167 #define DB_GET_FIELD(var, ta, ptr, type, field, idx) \
168 _td_fetch_value ((ta), (ta)->ta_field_##type##_##field, \
169 SYM_##type##_FIELD_##field, \
170 (psaddr_t) 0 + (idx), (ptr), &(var))
171
172 /* With GCC 5.3 when compiling with -Os the compiler emits a warning
173 that slot may be used uninitialized. This is never the case since
174 the dynamic loader initializes the slotinfo list and
175 dtv_slotinfo_list will point slot at the first entry. Therefore
176 when DB_GET_FIELD_ADDRESS is called with a slot for ptr, the slot is
177 always initialized. */
178 DIAG_PUSH_NEEDS_COMMENT;
179 DIAG_IGNORE_Os_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
180 #define DB_GET_FIELD_ADDRESS(var, ta, ptr, type, field, idx) \
181 ((var) = (ptr), _td_locate_field ((ta), (ta)->ta_field_##type##_##field, \
182 SYM_##type##_FIELD_##field, \
183 (psaddr_t) 0 + (idx), &(var)))
184 DIAG_POP_NEEDS_COMMENT;
185
186 extern td_err_e _td_locate_field (td_thragent_t *ta,
187 db_desc_t desc, int descriptor_name,
188 psaddr_t idx,
189 psaddr_t *address) attribute_hidden;
190
191
192 /* Like DB_GET_FIELD, but PTR is a local pointer to a structure that
193 has already been copied in from the inferior. */
194 #define DB_GET_FIELD_LOCAL(var, ta, ptr, type, field, idx) \
195 _td_fetch_value_local ((ta), (ta)->ta_field_##type##_##field, \
196 SYM_##type##_FIELD_##field, \
197 (psaddr_t) 0 + (idx), (ptr), &(var))
198
199 /* Store in psaddr_t VAR the value of variable NAME[IDX] in the inferior.
200 A target value smaller than psaddr_t is zero-extended. */
201 #define DB_GET_VALUE(var, ta, name, idx) \
202 (((ta)->ta_addr_##name == 0 \
203 && td_lookup ((ta)->ph, SYM_##name, &(ta)->ta_addr_##name) != PS_OK) \
204 ? TD_ERR \
205 : _td_fetch_value ((ta), (ta)->ta_var_##name, SYM_DESC_##name, \
206 (psaddr_t) 0 + (idx), (ta)->ta_addr_##name, &(var)))
207
208 /* Helper functions for those. */
209 extern td_err_e _td_fetch_value (td_thragent_t *ta,
210 db_desc_t field, int descriptor_name,
211 psaddr_t idx, psaddr_t address,
212 psaddr_t *result) attribute_hidden;
213 extern td_err_e _td_fetch_value_local (td_thragent_t *ta,
214 db_desc_t field,
215 int descriptor_name,
216 psaddr_t idx, void *address,
217 psaddr_t *result) attribute_hidden;
218
219 /* Store psaddr_t VALUE in ((TYPE) PTR)->FIELD[IDX] in the inferior.
220 A target field smaller than psaddr_t is zero-extended. */
221 #define DB_PUT_FIELD(ta, ptr, type, field, idx, value) \
222 _td_store_value ((ta), (ta)->ta_field_##type##_##field, \
223 SYM_##type##_FIELD_##field, \
224 (psaddr_t) 0 + (idx), (ptr), (value))
225
226 #define DB_PUT_FIELD_LOCAL(ta, ptr, type, field, idx, value) \
227 _td_store_value_local ((ta), (ta)->ta_field_##type##_##field, \
228 SYM_##type##_FIELD_##field, \
229 (psaddr_t) 0 + (idx), (ptr), (value))
230
231 /* Store psaddr_t VALUE in variable NAME[IDX] in the inferior.
232 A target field smaller than psaddr_t is zero-extended. */
233 #define DB_PUT_VALUE(ta, name, idx, value) \
234 (((ta)->ta_addr_##name == 0 \
235 && td_lookup ((ta)->ph, SYM_##name, &(ta)->ta_addr_##name) != PS_OK) \
236 ? TD_ERR \
237 : _td_store_value ((ta), (ta)->ta_var_##name, SYM_DESC_##name, \
238 (psaddr_t) 0 + (idx), (ta)->ta_addr_##name, (value)))
239
240 /* Helper functions for those. */
241 extern td_err_e _td_store_value (td_thragent_t *ta,
242 db_desc_t field, int descriptor_name,
243 psaddr_t idx, psaddr_t address,
244 psaddr_t value) attribute_hidden;
245 extern td_err_e _td_store_value_local (td_thragent_t *ta,
246 db_desc_t field, int descriptor_name,
247 psaddr_t idx, void *address,
248 psaddr_t value) attribute_hidden;
249
250 #define DB_GET_STRUCT(var, ta, ptr, type) \
251 ({ td_err_e _err = TD_OK; \
252 if ((ta)->ta_sizeof_##type == 0) \
253 _err = _td_check_sizeof ((ta), &(ta)->ta_sizeof_##type, \
254 SYM_SIZEOF_##type); \
255 if (_err == TD_OK) \
256 _err = ps_pdread ((ta)->ph, (ptr), \
257 (var) = __alloca ((ta)->ta_sizeof_##type), \
258 (ta)->ta_sizeof_##type) \
259 == PS_OK ? TD_OK : TD_ERR; \
260 else \
261 (var) = NULL; \
262 _err; \
263 })
264 #define DB_PUT_STRUCT(ta, ptr, type, copy) \
265 ({ assert ((ta)->ta_sizeof_##type != 0); \
266 ps_pdwrite ((ta)->ph, (ptr), (copy), (ta)->ta_sizeof_##type) \
267 == PS_OK ? TD_OK : TD_ERR; \
268 })
269
270 extern td_err_e _td_check_sizeof (td_thragent_t *ta, uint32_t *sizep,
271 int sizep_name) attribute_hidden;
272
273 extern td_err_e __td_ta_lookup_th_unique (const td_thragent_t *ta,
274 lwpid_t lwpid, td_thrhandle_t *th);
275
276 /* Try to initialize TA->ta_addr__rtld_global. Return true on
277 success, false on failure (which may be cached). */
278 bool __td_ta_rtld_global (td_thragent_t *ta) attribute_hidden;
279
280 /* Obtain the address of the list_t fields _dl_stack_user and
281 _dl_stack_used in _rtld_global, or fall back to the global
282 variables of the same name (to support statically linked
283 programs). */
284 td_err_e __td_ta_stack_user (td_thragent_t *ta, psaddr_t *plist)
285 attribute_hidden;
286 td_err_e __td_ta_stack_used (td_thragent_t *ta, psaddr_t *plist)
287 attribute_hidden;
288
289 #endif /* thread_dbP.h */