sysdeps/nptl/dl-tls_init_tp.c

   1 /* Completion of TCB initialization after TLS_INIT_TP.  NPTL version.
   2    Copyright (C) 2020-2021 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 <kernel-features.h>
  20 #include <ldsodefs.h>
  21 #include <list.h>
  22 #include <nptl/pthreadP.h>
  23 #include <tls.h>
  24
  25 #ifndef __ASSUME_SET_ROBUST_LIST
  26 bool __nptl_set_robust_list_avail __attribute__ ((nocommon));
  27 rtld_hidden_data_def (__nptl_set_robust_list_avail)
  28 #endif
  29
  30 bool __nptl_initial_report_events __attribute__ ((nocommon));
  31 rtld_hidden_def (__nptl_initial_report_events)
  32
  33 #ifdef SHARED
  34 /* Dummy implementation.  See __rtld_mutex_init.  */
  35 static int
  36 rtld_mutex_dummy (pthread_mutex_t *lock)
  37 {
  38   return 0;
  39 }
  40 #endif
  41
  42 void
  43 __tls_pre_init_tp (void)
  44 {
  45   /* The list data structures are not consistent until
  46      initialized.  */
  47   INIT_LIST_HEAD (&GL (dl_stack_used));
  48   INIT_LIST_HEAD (&GL (dl_stack_user));
  49   INIT_LIST_HEAD (&GL (dl_stack_cache));
  50
  51 #ifdef SHARED
  52   ___rtld_mutex_lock = rtld_mutex_dummy;
  53   ___rtld_mutex_unlock = rtld_mutex_dummy;
  54 #endif
  55 }
  56
  57 void
  58 __tls_init_tp (void)
  59 {
  60   /* Set up thread stack list management.  */
  61   list_add (&THREAD_SELF->list, &GL (dl_stack_user));
  62
  63    /* Early initialization of the TCB.   */
  64    struct pthread *pd = THREAD_SELF;
  65    pd->tid = INTERNAL_SYSCALL_CALL (set_tid_address, &pd->tid);
  66    THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]);
  67    THREAD_SETMEM (pd, user_stack, true);
  68
  69   /* Before initializing GL (dl_stack_user), the debugger could not
  70      find us and had to set __nptl_initial_report_events.  Propagate
  71      its setting.  */
  72   THREAD_SETMEM (pd, report_events, __nptl_initial_report_events);
  73
  74   /* Initialize the robust mutex data.  */
  75   {
  76 #if __PTHREAD_MUTEX_HAVE_PREV
  77     pd->robust_prev = &pd->robust_head;
  78 #endif
  79     pd->robust_head.list = &pd->robust_head;
  80     pd->robust_head.futex_offset = (offsetof (pthread_mutex_t, __data.__lock)
  81                                     - offsetof (pthread_mutex_t,
  82                                                 __data.__list.__next));
  83     int res = INTERNAL_SYSCALL_CALL (set_robust_list, &pd->robust_head,
  84                                      sizeof (struct robust_list_head));
  85     if (!INTERNAL_SYSCALL_ERROR_P (res))
  86       {
  87 #ifndef __ASSUME_SET_ROBUST_LIST
  88         __nptl_set_robust_list_avail = true;
  89 #endif
  90       }
  91   }
  92
  93   /* Set initial thread's stack block from 0 up to __libc_stack_end.
  94      It will be bigger than it actually is, but for unwind.c/pt-longjmp.c
  95      purposes this is good enough.  */
  96   THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end);
  97
  98   THREAD_SETMEM (pd, cancelstate, PTHREAD_CANCEL_ENABLE);
  99   THREAD_SETMEM (pd, canceltype, PTHREAD_CANCEL_DEFERRED);
 100 }