1 | /* Copyright (C) 2002-2016 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. |
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 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | #ifndef _DESCR_H |
20 | #define _DESCR_H 1 |
21 | |
22 | #include <limits.h> |
23 | #include <sched.h> |
24 | #include <setjmp.h> |
25 | #include <stdbool.h> |
26 | #include <sys/types.h> |
27 | #include <hp-timing.h> |
28 | #define __need_list_t |
29 | #include <list.h> |
30 | #include <lowlevellock.h> |
31 | #include <pthreaddef.h> |
32 | #include <dl-sysdep.h> |
33 | #include "../nptl_db/thread_db.h" |
34 | #include <tls.h> |
35 | #include <unwind.h> |
36 | #define __need_res_state |
37 | #include <resolv.h> |
38 | #include <kernel-features.h> |
39 | |
40 | #ifndef TCB_ALIGNMENT |
41 | # define TCB_ALIGNMENT sizeof (double) |
42 | #endif |
43 | |
44 | |
45 | /* We keep thread specific data in a special data structure, a two-level |
46 | array. The top-level array contains pointers to dynamically allocated |
47 | arrays of a certain number of data pointers. So we can implement a |
48 | sparse array. Each dynamic second-level array has |
49 | PTHREAD_KEY_2NDLEVEL_SIZE |
50 | entries. This value shouldn't be too large. */ |
51 | #define PTHREAD_KEY_2NDLEVEL_SIZE 32 |
52 | |
53 | /* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE |
54 | keys in each subarray. */ |
55 | #define PTHREAD_KEY_1STLEVEL_SIZE \ |
56 | ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \ |
57 | / PTHREAD_KEY_2NDLEVEL_SIZE) |
58 | |
59 | |
60 | |
61 | |
62 | /* Internal version of the buffer to store cancellation handler |
63 | information. */ |
64 | struct pthread_unwind_buf |
65 | { |
66 | struct |
67 | { |
68 | __jmp_buf jmp_buf; |
69 | int mask_was_saved; |
70 | } cancel_jmp_buf[1]; |
71 | |
72 | union |
73 | { |
74 | /* This is the placeholder of the public version. */ |
75 | void *pad[4]; |
76 | |
77 | struct |
78 | { |
79 | /* Pointer to the previous cleanup buffer. */ |
80 | struct pthread_unwind_buf *prev; |
81 | |
82 | /* Backward compatibility: state of the old-style cleanup |
83 | handler at the time of the previous new-style cleanup handler |
84 | installment. */ |
85 | struct _pthread_cleanup_buffer *cleanup; |
86 | |
87 | /* Cancellation type before the push call. */ |
88 | int canceltype; |
89 | } data; |
90 | } priv; |
91 | }; |
92 | |
93 | |
94 | /* Opcodes and data types for communication with the signal handler to |
95 | change user/group IDs. */ |
96 | struct xid_command |
97 | { |
98 | int syscall_no; |
99 | long int id[3]; |
100 | volatile int cntr; |
101 | volatile int error; /* -1: no call yet, 0: success seen, >0: error seen. */ |
102 | }; |
103 | |
104 | |
105 | /* Data structure used by the kernel to find robust futexes. */ |
106 | struct robust_list_head |
107 | { |
108 | void *list; |
109 | long int futex_offset; |
110 | void *list_op_pending; |
111 | }; |
112 | |
113 | |
114 | /* Data strcture used to handle thread priority protection. */ |
115 | struct priority_protection_data |
116 | { |
117 | int priomax; |
118 | unsigned int priomap[]; |
119 | }; |
120 | |
121 | |
122 | /* Thread descriptor data structure. */ |
123 | struct pthread |
124 | { |
125 | union |
126 | { |
127 | #if !TLS_DTV_AT_TP |
128 | /* This overlaps the TCB as used for TLS without threads (see tls.h). */ |
129 | tcbhead_t ; |
130 | #else |
131 | struct |
132 | { |
133 | /* multiple_threads is enabled either when the process has spawned at |
134 | least one thread or when a single-threaded process cancels itself. |
135 | This enables additional code to introduce locking before doing some |
136 | compare_and_exchange operations and also enable cancellation points. |
137 | The concepts of multiple threads and cancellation points ideally |
138 | should be separate, since it is not necessary for multiple threads to |
139 | have been created for cancellation points to be enabled, as is the |
140 | case is when single-threaded process cancels itself. |
141 | |
142 | Since enabling multiple_threads enables additional code in |
143 | cancellation points and compare_and_exchange operations, there is a |
144 | potential for an unneeded performance hit when it is enabled in a |
145 | single-threaded, self-canceling process. This is OK though, since a |
146 | single-threaded process will enable async cancellation only when it |
147 | looks to cancel itself and is hence going to end anyway. */ |
148 | int multiple_threads; |
149 | int gscope_flag; |
150 | # ifndef __ASSUME_PRIVATE_FUTEX |
151 | int private_futex; |
152 | # endif |
153 | } header; |
154 | #endif |
155 | |
156 | /* This extra padding has no special purpose, and this structure layout |
157 | is private and subject to change without affecting the official ABI. |
158 | We just have it here in case it might be convenient for some |
159 | implementation-specific instrumentation hack or suchlike. */ |
160 | void *__padding[24]; |
161 | }; |
162 | |
163 | /* This descriptor's link on the `stack_used' or `__stack_user' list. */ |
164 | list_t list; |
165 | |
166 | /* Thread ID - which is also a 'is this thread descriptor (and |
167 | therefore stack) used' flag. */ |
168 | pid_t tid; |
169 | |
170 | /* Process ID - thread group ID in kernel speak. */ |
171 | pid_t pid; |
172 | |
173 | /* List of robust mutexes the thread is holding. */ |
174 | #ifdef __PTHREAD_MUTEX_HAVE_PREV |
175 | void *robust_prev; |
176 | struct robust_list_head robust_head; |
177 | |
178 | /* The list above is strange. It is basically a double linked list |
179 | but the pointer to the next/previous element of the list points |
180 | in the middle of the object, the __next element. Whenever |
181 | casting to __pthread_list_t we need to adjust the pointer |
182 | first. */ |
183 | # define QUEUE_PTR_ADJUST (offsetof (__pthread_list_t, __next)) |
184 | |
185 | # define ENQUEUE_MUTEX_BOTH(mutex, val) \ |
186 | do { \ |
187 | __pthread_list_t *next = (__pthread_list_t *) \ |
188 | ((((uintptr_t) THREAD_GETMEM (THREAD_SELF, robust_head.list)) & ~1ul) \ |
189 | - QUEUE_PTR_ADJUST); \ |
190 | next->__prev = (void *) &mutex->__data.__list.__next; \ |
191 | mutex->__data.__list.__next = THREAD_GETMEM (THREAD_SELF, \ |
192 | robust_head.list); \ |
193 | mutex->__data.__list.__prev = (void *) &THREAD_SELF->robust_head; \ |
194 | THREAD_SETMEM (THREAD_SELF, robust_head.list, \ |
195 | (void *) (((uintptr_t) &mutex->__data.__list.__next) \ |
196 | | val)); \ |
197 | } while (0) |
198 | # define DEQUEUE_MUTEX(mutex) \ |
199 | do { \ |
200 | __pthread_list_t *next = (__pthread_list_t *) \ |
201 | ((char *) (((uintptr_t) mutex->__data.__list.__next) & ~1ul) \ |
202 | - QUEUE_PTR_ADJUST); \ |
203 | next->__prev = mutex->__data.__list.__prev; \ |
204 | __pthread_list_t *prev = (__pthread_list_t *) \ |
205 | ((char *) (((uintptr_t) mutex->__data.__list.__prev) & ~1ul) \ |
206 | - QUEUE_PTR_ADJUST); \ |
207 | prev->__next = mutex->__data.__list.__next; \ |
208 | mutex->__data.__list.__prev = NULL; \ |
209 | mutex->__data.__list.__next = NULL; \ |
210 | } while (0) |
211 | #else |
212 | union |
213 | { |
214 | __pthread_slist_t robust_list; |
215 | struct robust_list_head robust_head; |
216 | }; |
217 | |
218 | # define ENQUEUE_MUTEX_BOTH(mutex, val) \ |
219 | do { \ |
220 | mutex->__data.__list.__next \ |
221 | = THREAD_GETMEM (THREAD_SELF, robust_list.__next); \ |
222 | THREAD_SETMEM (THREAD_SELF, robust_list.__next, \ |
223 | (void *) (((uintptr_t) &mutex->__data.__list) | val)); \ |
224 | } while (0) |
225 | # define DEQUEUE_MUTEX(mutex) \ |
226 | do { \ |
227 | __pthread_slist_t *runp = (__pthread_slist_t *) \ |
228 | (((uintptr_t) THREAD_GETMEM (THREAD_SELF, robust_list.__next)) & ~1ul); \ |
229 | if (runp == &mutex->__data.__list) \ |
230 | THREAD_SETMEM (THREAD_SELF, robust_list.__next, runp->__next); \ |
231 | else \ |
232 | { \ |
233 | __pthread_slist_t *next = (__pthread_slist_t *) \ |
234 | (((uintptr_t) runp->__next) & ~1ul); \ |
235 | while (next != &mutex->__data.__list) \ |
236 | { \ |
237 | runp = next; \ |
238 | next = (__pthread_slist_t *) (((uintptr_t) runp->__next) & ~1ul); \ |
239 | } \ |
240 | \ |
241 | runp->__next = next->__next; \ |
242 | mutex->__data.__list.__next = NULL; \ |
243 | } \ |
244 | } while (0) |
245 | #endif |
246 | #define ENQUEUE_MUTEX(mutex) ENQUEUE_MUTEX_BOTH (mutex, 0) |
247 | #define ENQUEUE_MUTEX_PI(mutex) ENQUEUE_MUTEX_BOTH (mutex, 1) |
248 | |
249 | /* List of cleanup buffers. */ |
250 | struct _pthread_cleanup_buffer *cleanup; |
251 | |
252 | /* Unwind information. */ |
253 | struct pthread_unwind_buf *cleanup_jmp_buf; |
254 | #define HAVE_CLEANUP_JMP_BUF |
255 | |
256 | /* Flags determining processing of cancellation. */ |
257 | int cancelhandling; |
258 | /* Bit set if cancellation is disabled. */ |
259 | #define CANCELSTATE_BIT 0 |
260 | #define CANCELSTATE_BITMASK (0x01 << CANCELSTATE_BIT) |
261 | /* Bit set if asynchronous cancellation mode is selected. */ |
262 | #define CANCELTYPE_BIT 1 |
263 | #define CANCELTYPE_BITMASK (0x01 << CANCELTYPE_BIT) |
264 | /* Bit set if canceling has been initiated. */ |
265 | #define CANCELING_BIT 2 |
266 | #define CANCELING_BITMASK (0x01 << CANCELING_BIT) |
267 | /* Bit set if canceled. */ |
268 | #define CANCELED_BIT 3 |
269 | #define CANCELED_BITMASK (0x01 << CANCELED_BIT) |
270 | /* Bit set if thread is exiting. */ |
271 | #define EXITING_BIT 4 |
272 | #define EXITING_BITMASK (0x01 << EXITING_BIT) |
273 | /* Bit set if thread terminated and TCB is freed. */ |
274 | #define TERMINATED_BIT 5 |
275 | #define TERMINATED_BITMASK (0x01 << TERMINATED_BIT) |
276 | /* Bit set if thread is supposed to change XID. */ |
277 | #define SETXID_BIT 6 |
278 | #define SETXID_BITMASK (0x01 << SETXID_BIT) |
279 | /* Mask for the rest. Helps the compiler to optimize. */ |
280 | #define CANCEL_RESTMASK 0xffffff80 |
281 | |
282 | #define CANCEL_ENABLED_AND_CANCELED(value) \ |
283 | (((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK \ |
284 | | CANCEL_RESTMASK | TERMINATED_BITMASK)) == CANCELED_BITMASK) |
285 | #define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \ |
286 | (((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK \ |
287 | | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK)) \ |
288 | == (CANCELTYPE_BITMASK | CANCELED_BITMASK)) |
289 | |
290 | /* Flags. Including those copied from the thread attribute. */ |
291 | int flags; |
292 | |
293 | /* We allocate one block of references here. This should be enough |
294 | to avoid allocating any memory dynamically for most applications. */ |
295 | struct pthread_key_data |
296 | { |
297 | /* Sequence number. We use uintptr_t to not require padding on |
298 | 32- and 64-bit machines. On 64-bit machines it helps to avoid |
299 | wrapping, too. */ |
300 | uintptr_t seq; |
301 | |
302 | /* Data pointer. */ |
303 | void *data; |
304 | } specific_1stblock[PTHREAD_KEY_2NDLEVEL_SIZE]; |
305 | |
306 | /* Two-level array for the thread-specific data. */ |
307 | struct pthread_key_data *specific[PTHREAD_KEY_1STLEVEL_SIZE]; |
308 | |
309 | /* Flag which is set when specific data is set. */ |
310 | bool specific_used; |
311 | |
312 | /* True if events must be reported. */ |
313 | bool report_events; |
314 | |
315 | /* True if the user provided the stack. */ |
316 | bool user_stack; |
317 | |
318 | /* True if thread must stop at startup time. */ |
319 | bool stopped_start; |
320 | |
321 | /* The parent's cancel handling at the time of the pthread_create |
322 | call. This might be needed to undo the effects of a cancellation. */ |
323 | int parent_cancelhandling; |
324 | |
325 | /* Lock to synchronize access to the descriptor. */ |
326 | int lock; |
327 | |
328 | /* Lock for synchronizing setxid calls. */ |
329 | unsigned int setxid_futex; |
330 | |
331 | #if HP_TIMING_AVAIL |
332 | /* Offset of the CPU clock at start thread start time. */ |
333 | hp_timing_t cpuclock_offset; |
334 | #endif |
335 | |
336 | /* If the thread waits to join another one the ID of the latter is |
337 | stored here. |
338 | |
339 | In case a thread is detached this field contains a pointer of the |
340 | TCB if the thread itself. This is something which cannot happen |
341 | in normal operation. */ |
342 | struct pthread *joinid; |
343 | /* Check whether a thread is detached. */ |
344 | #define IS_DETACHED(pd) ((pd)->joinid == (pd)) |
345 | |
346 | /* The result of the thread function. */ |
347 | void *result; |
348 | |
349 | /* Scheduling parameters for the new thread. */ |
350 | struct sched_param schedparam; |
351 | int schedpolicy; |
352 | |
353 | /* Start position of the code to be executed and the argument passed |
354 | to the function. */ |
355 | void *(*start_routine) (void *); |
356 | void *arg; |
357 | |
358 | /* Debug state. */ |
359 | td_eventbuf_t eventbuf; |
360 | /* Next descriptor with a pending event. */ |
361 | struct pthread *nextevent; |
362 | |
363 | /* Machine-specific unwind info. */ |
364 | struct _Unwind_Exception exc; |
365 | |
366 | /* If nonzero pointer to area allocated for the stack and its |
367 | size. */ |
368 | void *stackblock; |
369 | size_t stackblock_size; |
370 | /* Size of the included guard area. */ |
371 | size_t guardsize; |
372 | /* This is what the user specified and what we will report. */ |
373 | size_t reported_guardsize; |
374 | |
375 | /* Thread Priority Protection data. */ |
376 | struct priority_protection_data *tpp; |
377 | |
378 | /* Resolver state. */ |
379 | struct __res_state res; |
380 | |
381 | /* This member must be last. */ |
382 | char end_padding[]; |
383 | |
384 | #define PTHREAD_STRUCT_END_PADDING \ |
385 | (sizeof (struct pthread) - offsetof (struct pthread, end_padding)) |
386 | } __attribute ((aligned (TCB_ALIGNMENT))); |
387 | |
388 | |
389 | #endif /* descr.h */ |
390 | |